Flaps Flashcards
A Z-plasty revision procedure is to be performed for lengthening of a scar contracture. In order to achieve a theoretical 100% gain in the length, the angle of the Z-plasty should be how many degrees?
(A) 30
(B) 45
(C) 60
(D) 75
(E) 90
The correct response is Option D.
The Z-plasty is a technique in which pairs of triangular transposition flaps are created adjacent to a scar and then transposed across the scar, resulting in an increase in the length of the central limb and a change in the orientation of the scar. This technique can be used in patients undergoing burn reconstruction to lengthen linear scar contractures, disperse linear scars, and realign the scars within the lines of minimal tension. The actual amount of scar lengthening correlates directly with the angle and length of the flap limbs, as demonstrated in the table above.
A vastus lateralis muscle flap elevated on its dominant pedicle provides reliable coverage for each of the following anatomic sites EXCEPT the
(A) acetabulum
(B) groin
(C) knee
(D) perineum
(E) trochanter
The correct response is Option C.
When the vastus lateralis flap is based on its dominant pedicle, the descending branch of the lateral femoral circumflex artery, it has an area of rotation that will provide vascularized coverage of the lower abdomen, groin, perineum, ischium, trochanter, and acetabular fossa. However, the flap must be reversed in order to rotate and provide coverage of knee defects. When used in this manner, the flap is then based on a branch of the lateral genicular artery, which is a minor distal pedicle. Because the risk for partial flap loss is greater, this flap is not often advocated for coverage of knee defects.
A 58-year-old man undergoes a left hemimandibulectomy. Reconstruction with an osteocutaneous free flap harvested from the ipsilateral pelvis is planned. The vascular pedicle supplying this flap is based on which of the following arteries?
A) Ascending branch of the lateral circumflex femoral artery
B) Deep circumflex iliac artery
C) Deep inferior epigastric artery
D) Descending branch of the geniculate artery
E) Peroneal artery
The correct response is Option B.
The deep circumflex iliac artery arises from the external iliac artery and is the blood supply to the iliac crest osteocutaneous flap. This flap can be harvested either as a bone-only or an osteocutaneous free flap. It is often used in hemimandibular reconstruction because the natural curvature of the iliac crest closely resembles the shape of the hemimandible. A portion of the internal oblique muscle, based on the ascending branch of the deep circumflex iliac artery, can also be included with this flap.
The descending branch of the geniculate artery is the blood supply to the medial femoral condyle flap. The ascending branch of the lateral circumflex femoral artery is the blood supply to the tensor fascia lata flap. The peroneal artery is the blood supply to the fibula flap. The deep inferior epigastric artery is the blood supply to the rectus abdominis myocutaneous flap.
A 50-year-old man is scheduled to undergo resection of a squamous cell cancer of the right floor of the mouth with invasion into the mandibular body. Composite resection of the right hemimandible and a 2-cm resection of the floor of the mouth followed by immediate reconstruction with a fibula flap are planned, necessitating the use of an osteocutaneous flap. Which of the following best describes the course of the blood supply for the skin paddle of this flap?
A) Musculocutaneus and septocutaneous perforators from the peroneus longus and brevis muscles
B) Musculocutaneus perforators from the flexor hallucis brevis muscle
C) Septocutaneous and musculocutaneus perforators from the anterior tibialis muscle
D) Septocutaneous perforators from the posterior intermuscular septum
E) Septocutaneous perforators from the posterior tibialis muscle
The correct response is Option D.
The blood supply for the fibula flap skin paddle used for reconstruction arises from septocutaneous perforators from the peroneal artery that traverse the posterior intermuscular septum. The position of these vessels can be marked before the procedure with a pencil Doppler probe. In the majority of cases, the blood supply to the fibula flap skin paddle is reliable for microsurgical transfer. The skin flap also has blood supply arising from musculocutaneus perforators originating from the soleus and gastrocnemius muscles; however, these vessels are, in most cases, ligated because their dissection is tedious, and they often arise from the posterior tibial artery. The anterior and posterior tibialis muscles do not provide blood supply to the fibula flap skin paddle.
A 35-year-old man undergoes coverage of a soft-tissue defect on the posterior right elbow with a reverse lateral arm flap. He does not have a history of serious illness and has never smoked cigarettes. Vascular examination shows no abnormalities. Arterial blood to the flap is provided primarily by which of the following arteries?
A ) Artery to the biceps muscle
B ) Inferior cubital
C ) Musculocutaneous perforating branches from the brachioradialis muscle
D ) Posterior radial collateral
E ) Radial recurrent
The correct response is Option E.
The most likely dominant arterial supply to the reverse lateral arm flap is the radial recurrent artery. It is a branch of the radial artery and arises in the cubital fossa. It anastomoses with the posterior radial collateral artery just above the lateral epicondyle and medial to the brachioradialis within the lateral intermuscular septum. This pedicled flap can be used to cover defects of the elbow and requires retrograde flow through the posterior radial collateral artery via the radial recurrent artery. Prior trauma or radical surgery around the elbow and severe peripheral vascular disease warrant confirmation of presence or patency of the pedicle via Doppler ultrasonography or angiography. After rotating this flap more than 180 degrees, venous insufficiency may result and require microanastomosis of a superficial vein in the flap to a receptor vein in the defect to augment outflow.
The posterior radial collateral artery is the dominant inflow for the standard lateral arm flap. The inferior cubital artery is the dominant inflow and the musculocutaneous perforating branches from the brachioradialis muscle are the minor pedicles for the antecubital flap. The artery to the biceps muscle supplies the medial arm flap.
A 35-year-old man is undergoing repair of a pressure sore on the left ischium using the musculocutaneous flap shown in the photograph. Which of the following is the Mathes and Nahai classification of this flap?
A ) Type I
B ) Type II
C ) Type III
D ) Type IV
E ) Type V
The correct response is Option C.
The gluteal musculocutaneous flap is a Type III flap, meaning it has two dominant pedicles (the superior and inferior gluteal arteries). These arteries are separated by the piriformis muscle and are sourced to the internal iliac system.
A Type I flap has a single dominant pedicle (ie, tensor fascia lata). A Type II flap has dominant and minor pedicle(s) (ie, gracilis). A Type IV flap has multiple segmental pedicles (ie, sartorius). A Type V flap has a dominant pedicle and secondary segmental pedicles (ie, latissimus).
A 45-year-old woman is brought to the emergency department after sustaining a shotgun injury to the nondominant left forearm. A preoperative x-ray study is shown. Bone stabilization is performed. The ulnar nerve, multiple flexor tendons, and the ulnar artery are repaired during surgery and are left exposed. A photograph taken following the repair is shown. The wound was covered with allograft skin while viability of the hand was confirmed for 2 days. Which of the following is the most appropriate definitive coverage for the wound?
A) Free anterolateral thigh flap
B) Full-thickness skin grafting from the groin
C) Pedicled groin flap
D) Reverse lateral arm flap
E) Split-thickness skin grafting from the thigh
The correct response is Option A.
Shotgun blasts at close range can create a devastating pattern of injury. X-ray study shows a heavily comminuted ulna fracture. The scenario also involves tendon, vascular, and nerve injury. In choosing the appropriate coverage for the wound described, the surgeon will need to consider the protection of exposed structures, the ability to rehabilitate the extremity, and the possible need for future surgery on the arm.
A free tissue transfer will provide viable, full-thickness tissue from a nontraumatized area to cover the wound. Many donor sites are available, including fasciocutaneous flaps such as the anterolateral thigh flap, as well as muscle flaps. Some authors advocate fasciocutaneous flaps over muscle flaps with the rationale that the fat on the deep surface of the flap will better allow glide of tendons and nerves deep to it; in addition, a fasciocutaneous flap, once healed, can be incised like normal skin for any future surgery that might be necessary in the patient’s arm. A photograph is shown.
Skin grafting, whether split-thickness or full-thickness, carries several liabilities. Both types of grafts provide skin but no subcutaneous tissue. In addition, both heal by adhering to the wound bed. Because the patient described has exposed tendon in the wound bed, skin grafting would likely cause significant tendon adhesions and thus impaired mobility. In addition, adhesion of the skin graft to a nerve, particularly a repaired nerve, carries a risk of chronic pain and nerve dysfunction.
A pedicled groin flap can provide thin, pliable, full-thickness tissue to cover defects of the forearm. However, the flap is done as a two-staged procedure, with the arm tethered to the groin for 2 to 3 weeks to allow vascular ingrowth. In the patient described, having the arm dependent for that period of time would significantly worsen edema and compromise the ability to begin rehabilitation of the extremity.
A reversed lateral arm flap provides full-thickness soft-tissue coverage for defects about the elbow. Its harvest does not require sacrifice of a major artery to the hand. The lateral arm flap would not be able to reach the distal limit of the wound described. In addition, the lateral arm flap donor site can be closed primarily for flaps up to 12 × 6 cm, which is significantly smaller than the wound in the patient described.
A 28-year-old woman presents to the clinic 3 years after she sustained large, full-thickness burns to the anterior neck. She has undergone reconstruction with a fasciocutaneous free flap. She does not like the contracture and webbing along the margin of the reconstruction. Two contiguous 45-degree Z-plasties are planned over a total length of 10 cm. The expected increase in scar length is which of the following?
A) 2.5 cm
B) 5.0 cm
C) 7.5 cm
D) 10.0 cm
E) 12.5 cm
The correct response is Option B.
A 45-degree Z-plasty is expected to lengthen the total scar by 50%. If each Z-plasty covers 5 cm of scar, then each Z-plasty will increase scar length by 2.5 cm, for a total increase of 5 cm. Theoretical gains in length for Z-plasty angles are as follows:
The Z-plasty was the first flap introduced using a mathematical approach to correct a skin defect or scar. A standard Z-plasty design uses three incisions of equal length and two angles of equal degree. The primary principle is to transfer lateral skin excess to lengthen and reorient tight scars or contractures. The central incision is oriented parallel to the long axis of the scar, or the scar may be incorporated as an excision acting as the central incision. The resultant triangular skin flaps are transposed with each other, resulting in a new central incision that is perpendicular to the original orientation.
A patient with a complex defect that requires replacement of skin, muscle, and bone is scheduled to have reconstruction with a single free flap from the subscapular system. Which of the following would NOT be used as part of this reconstruction?
(A) Parascapular fasciocutaneous tissue
(B) Serratus anterior muscle
(C) Trapezius muscle
(D) Vascularized rib
(E) Vascularized scapular bone
The correct response is Option C.
Unlike the other tissues, the trapezius muscle is based on the transverse cervical artery (based on the thyrocervical trunk in 80% of cases or the subclavian artery in 20% of cases). The subscapular system allows for the creation of chimeric flaps that can include bone, muscle, fascia, fat, and skin. Flaps that have been used include the serratus anterior muscle and fascia, latissimus dorsi muscle and fascia, scapular and parascapular fascia and overlying skin, and scapular and rib bone. Such combinations allow for versatility in reconstructing complex three €‘dimensional defects that are often encountered in the face.
A 75-year-old man who had femoral-popliteal bypass surgery 2 weeks ago has an infection in the proximal groin. A muscle flap to fill the dead space is planned. Which of the following muscle flap options has a type IV Mathes-Nahai (multiple segmental vascular pedicles) vascular anatomy?
A) Gracilis
B) Rectus abdominis
C) Rectus femoris
D) Sartorius
E) Vastus medialis
The correct response is Option D.
The sartorius muscle classically has a type IV Mathes-Nahai vascular anatomy, which may limit its arc of rotation. In a recent study, even though the sartorius muscle has multiple segmental pedicles, there tend to be codominant superior and inferior pedicles that could possibly allow for the majority of the muscle to be raised on either the superior or inferior dominant pedicle.
Mathes-Nahai vascular anatomy classification for muscle flaps:
I – Single dominant vascular pedicle
II – Single dominant vascular pedicle with secondary minor vascular pedicles
III – Codominant major vascular pedicles
IV – Multiple segmental vascular pedicles
V – Dominant vascular pedicle with segmental secondary pedicles that can supply muscle if dominant is divided
Type II vascular anatomy is seen with the rectus femoris, vastus medialis, and gracilis muscles. The rectus abdominis has a type III vascular anatomy. Type V would be a latissimus dorsi muscle flap.
Which of the following vessels runs within the pedicle of the reverse sural artery flap and serves as primary venous drainage?
A) Femoral
B) Greater saphenous
C) Lesser saphenous
D) Popliteal
E) Posterior tibial
The correct response is Option C.
The reverse superficial sural artery flap (RSSAF) is a distally based fasciocutaneous or adipofascial flap that is increasingly being used for coverage of defects that involve the distal third of the leg, ankle, and foot. First described by Donski and Fogdestam and later championed by Masquelet et al, RSSAF has become a popular option for these difficult wounds. The description of the RSSAF (Masquelet flap) has revolutionized the osteoplastic armamentarium of surgeons not conversant with microvascular free flaps. The reliability of septocutaneous perforators has been well documented. Hence, raising a flap based on this reliable anastomosis of peroneal artery and median sural artery, along with the sural nerve and lesser (short) saphenous vein has been described to be successful.
A significant advantage of this flap is that it does not require sacrifice of a major artery to the lower limb. Touted for its ease of dissection, the RSSAF is often reputed to have a favorable complication profile as evidenced by a recent meta-analysis that found 82% of flaps heal without any flap-related complications. The main complications include venous congestion of the flap requiring delay or leech therapy in some higher-risk patients.
The greater saphenous vein runs proximal and medial to the lesser saphenous vein, and it drains the medial and anteromedial portion of the lower leg.
The popliteal vein drains the lesser (short) saphenous vein, and it is therefore not the primary drainage of the reverse sural flap. The anterior and posterior tibial veins are the deep venous drainage of the lower leg and do not drain the RSSAF.
The femoral vein is the deep venous drainage system in the upper leg.
A 5-year-old boy presents to the emergency department 4 hours after he sustained an amputation of his left index finger when it was slammed in a door. The parents brought the amputated digit in a plastic bag on ice. The amputation is at the level of the mid proximal phalanx. Which of the following is the most important reason to attempt replantation?
A) The amputation is proximal to the flexor digitorum superficialis insertion
B) The cold ischemia time is less than 6 hours
C) It is the index finger
D) It is a single-digit amputation
E) The patient is a child
The correct response is Option E.
Digital replantation should almost always be attempted in a child, except when the amputated part is severely crushed or there are other life-threatening injuries that preclude surgery. Replantation in children is technically more challenging due to the smaller size of the vessels. However, functional outcomes are more superior than in adults. The replanted parts have better sensory return and can have normal growth. Amputations through joints also exhibit remarkable joint remodeling.
A single digit amputation, especially proximal to the flexor digitorum superficialis (FDS) insertion is considered a contraindication to replantation. Digit replantations proximal to the FDS insertion have a poor range of motion as compared to amputations distal to the FDS insertion. This is, thus, an important landmark when making decisions about amputation versus replantation. Multiple digit amputations are an indication for replantation as the functioning deficit with loss of multiple digits is great. The thumb is responsible for 40% of the function of the hand and should always be replanted, if possible. Even if it is stiff and insensate, a replanted thumb will act as a post for opposition.
Index finger amputations at or proximal to the proximal interphalangeal joint are considered by many to be an indication for amputation. A stiff and painful index finger is likely to be excluded by the patient; amputation will result in better global hand function.
Digits tolerate longer ischemia times than more proximal level amputations, due to absence of muscle. Amputated digits tolerate warm ischemia times of 6 to 12 hours and cold ischemia times of 12 to 24 hours. Digital replantation has been reported with warm ischemia time of 33 hours and cold ischemia time of 94 hours. Cold ischemia time is thus not a major consideration in the decision-making process for amputation versus replantation.
Which of the following arteries is the major blood supply to the flap most often used in the reconstruction of open-knee defects?
(A) Anterior tibial
(B) Medial circumflex femoral
(C) Peroneal
(D) Posterior tibial
(E) Sural
The correct response is Option E.
The medial and lateral sural arteries supply circulation to the gastrocnemius muscle, which, when released and rotated proximally, provides the best coverage for complex knee wounds. The gastrocnemius muscle may be harvested with overlying skin or may be skin-grafted.
The medial circumflex femoral artery and profunda femoris vessels supply the gracilis muscle, which provides coverage for medial thigh and groin defects. It cannot be rotated distally.
The posterior tibial artery provides some blood supply to the soleus muscle, which is the preferred muscle coverage to wounds to the middle one third of the lower extremity. The posterior tibial, peroneal, and anterior tibial arteries provide perforators for fasciocutaneous flaps in the lower extremity, which are limited in their applicability and are too distal for coverage of the wound.
A 46-year-old man undergoes resection of a sarcoma involving the posterior neck. Photographs are shown. Which of the following arteries supplies the musculocutaneous flap used to reconstruct this defect?
A ) Circumflex scapular
B ) Deep temporal
C ) Internal carotid
D) Superficial temporal
E ) Transverse cervical
The correct response is Option E.
The transverse cervical artery is the blood supply to the trapezius flap which is used to reconstruct the defect described. The circumflex scapular artery is the blood supply to the scapular/parascapular flap. This artery has a length of approximately 6 to 7 cm and does not have the arc of rotation to reach a posterior neck defect. The deep temporal artery is the blood supply of the temporalis muscle. The arc of rotation of this muscle does not enable repair of posterior neck defects. The internal carotid artery does not give rise to branches that supply the muscles of the neck/back that may be useful for reconstruction of this defect. The superficial temporal artery is the blood supply of the superficial temporal fascia. This flap is quite thin with a limited reach and would not be appropriate for reconstruction of an extensive resection that includes skin, subcutaneous tissues, and muscle as shown.
In a patient who has undergone resection of a squamous cell carcinoma of the floor of the mouth, which of the following free flaps will provide vascularized bone and a sensate skin paddle?
(A) Iliac crest flap
(B) Lateral arm flap
(C) Parascapular flap
(D) Serratus anterior flap
The correct response is Option B.
Because the lateral arm flap provides both vascularized bone and a sensate skin paddle, it is best used for reconstruction of this patient’s defect involving the floor of the mouth. Vascularity and skin sensibility are provided by the radial collateral artery and posterior brachial cutaneous nerve (C5-6), respectively. As much as 7 cm * 12 cm of skin can be elevated with the flap; in addition, because of its periosteal attachments, as much as one-third of the posterior lateral humerus (or 10 cm to 15 cm in length and 1 cm to 1.5 cm in diameter) can be harvested.
The iliac crest osteocutaneous flap, which is based on the deep circumflex iliac artery, can provide a skin paddle as large as 12 cm * 6 cm and a bone segment as large as 8 cm ( 18 cm. Although this flap can be used for reconstruction of large mandibular segments and extensive soft-tissue defects, the skin component is bulky and insensate. Meticulous closure of the donor site defect is required to prevent hernia formation.
The parascapular flap is based on the circumflex scapular artery. Advantages of this flap include multiple skin paddles, a large segment of bone, and a high degree of independent motion between the skin and bone segments. The serratus anterior and/or latissimus dorsi muscles can be included with the flap to reconstruct complex defects. However, the skin paddles of this flap are also bulky and lack a cutaneous sensory nerve.
The serratus anterior flap is extremely versatile. Skin, muscle, and an iliac bone graft can be included with this flap; its pedicle is long and has a large diameter. It can be harvested as a functional muscle flap with inclusion of the branches of the long thoracic nerve; however, the upper four to five muscle slips must be preserved in order to prevent winging of the scapula. This primary disadvantage of this flap is that any bone incorporated with it will be less substantial and have poor vascularization when compared with other osteocutaneous flaps. The skin component of this flap is also insensate.
A 55-year-old woman is scheduled to undergo surgery for soft-tissue coverage of an open joint elbow wound. The vascular pedicle of the flap in the photograph shown passes between which of the following tendons?
A) Brachioradialis and abductor pollicis longus
B) Brachioradialis and flexor carpi radialis
C) Brachioradialis and flexor pollicis longus
D) Brachioradialis and pronator teres
E) Flexor carpi radialis and pronator teres
The correct response is Option B.
The clinical image shown depicts a radial forearm flap. The vascular pedicle of the radial forearm flap is the radial artery that is a branch of the brachial artery. Proximally, the radial artery runs deep to the brachioradialis muscle and it passes distally between the bellies of the brachioradialis and flexor carpi radialis. The radial forearm flap cutaneous paddle is perfused by septocutaneous perforators from the radial artery.
The other options are incorrect because the vascular pedicle does not pass between those muscles.
References
A 14-year-old girl who has flexion deformities of the right wrist and fingers, numbness of the radial-volar hand, and forearm atrophy 6 months after sustaining an electrical burn to the right upper extremity is brought for evaluation. A functional free gracilis muscle transfer is planned to improve finger flexion. Which of the following nerves innervates this flap?
A) Femoral
B) Genitofemoral
C) Ilioinguinal
D) Obturator
E) Pudendal
The correct response is Option D.
The gracilis muscle is the workhorse for functional muscle transfer, and it has been successfully used to restore hand function in patients with severe Volkmann ischemic contracture. Innervation of the muscle is via a branch of the obturator nerve, which is composed of 2 to 3 fascicular bundles. The nerve length from its emergence from the obturator foramen to its insertion into the muscle averages 7.7 cm, and separation of the fascicular bundles can allow the muscle to be segmented. The other nerves listed do not innervate the gracilis muscle.
A 52-year-old man is brought to the emergency department after sustaining injuries in a motor vehicle collision. Physical examination shows a traumatic degloving injury to the dorsum of the right hand with exposed, intact extensor tendons. Reconstruction with a fascial free flap and full-thickness skin grafting are planned. Which of the following arteries supplies blood to the most appropriate choice of flap?
A) Posterior auricular
B) Superficial temporal
C) Superior thyroid
D) Supratrochlear
E) Transverse facial
The correct response is Option B.
The temporoparietal fascial flap is supplied by the superficial temporal artery. This thin fascial free flap is useful in reconstruction of traumatic injuries that are not amenable to reconstruction with a skin graft alone. This flap is particularly useful in reconstruction of gliding surfaces with denuded tendons or exposed joints.
The posterior auricular artery is a branch of the external carotid artery and supplies the posterior ear. The superior thyroid artery arises from the external carotid artery and supplies the thyroid gland. The supratrochlear artery supplies the forehead and scalp. The transverse facial artery is a branch of the superficial temporal artery and supplies the parotid gland. None of these vessels is involved in the vascular supply of the temporoparietal fascial flap.
An 18-year-old man is scheduled to undergo free fibula flap for mandible reconstruction. The patient reports that he is a track and field athlete. Regarding the function of his great toe, which of the following is the most likely outcome?
A) Abduction deformity
B) Decreased flexion strength
C) Neuropathic pain
D) Normal extension
The correct response is Option B.
The fibula free flap is commonly used for mandibular reconstruction because of the availability of up to 25 cm of bone. However, donor site morbidity is a significant consideration and is common with this flap. Common motor morbidity includes impaired flexor hallucis longus (FHL) function, with a significant reduction in strength between the affected and unaffected legs. As a result of loss of the FHL and decreased opposition to the long toe flexors, claw toe deformity and weakened dorsiflexion are also common. Gait may be affected by these deformities.
Sensory deficits typically include the peroneal nerve distribution and may cause pain at the operative site or sensory deficits over the dorsum of the foot.
A 35-year-old man sustains a traumatic injury to the lower leg and undergoes closure of the wound using an anterolateral thigh free flap (shown). A cuff of muscle is harvested with the flap to fill a bone defect. Which of the following muscles can be safely harvested while using the same vascular pedicle as the flap?
A ) Adductor longus
B ) Rectus abdominis
C ) Vastus intermedius
D ) Vastus lateralis
E ) Vastus medialis
The correct response is Option D.
The anterolateral thigh flap is located over the lateral third of the thigh, between the borders of the rectus femoris and vastus lateralis muscle. Its blood supply comes from perforating branches of the lateral circumflex femoral artery and its venae comitantes. These vessels arise from the profunda femoris artery and vein. By utilizing the transverse branch of the lateral femoral circumflex artery and venae comitantes and their musculocutaneous perforators, the vastus lateralis muscle can be harvested with the anterolateral thigh flap. This muscle can be used for added bulk in the flap. The anterolateral thigh flap may also be harvested with the tensor fascia lata muscle. This flap may also be used as a functional muscle transfer.
The deep inferior epigastric artery arises from which of the following arteries?
(A) External iliac
(B) Femoral
(C) Internal iliac
(D) Internal mammary
(E) Superficial inferior epigastric
The correct response is Option A.
The deep inferior epigastric artery and vein arise from the external iliac artery at a point just proximal to where the artery passes beneath the inguinal ligament.
The internal mammary vessels provide the regional source for the superior epigastric artery. The femoral, internal iliac, and superficial inferior epigastric arteries are not source vessels for the deep inferior epigastric artery and vein. The femoral artery originates as the external iliac vessels exit from the inguinal ligament. The internal iliac artery supplies blood to structures within the pelvis.
A 65-year-old woman has a draining sinus tract at the lower chest 2 weeks after undergoing a cardiac bypass procedure. After extensive debridement, there is a large central defect requiring an omental flap for obliteration of the dead space. Which of the following arteries supplies the omental flap?
A) Gastroduodenal
B) Gastroepiploic
C) Left gastric
D) Superior epigastric
E) Superior mesenteric
The correct response is Option B.
The blood supply to the omental flap is through the right and left gastroepiploic arteries.
Understanding the anatomy and blood supply to the omentum is crucial for success in omental flap transfer. The greater omentum is harvested from the transverse colon, as the short gastric vessels are ligated and the gastroepiploic vessels preserved. The omentum can be transposed to the chest through either an opening in the diaphragm or a fascial defect in the abdominal wall.
The left gastric vessels arise from the celiac vessels and supply the lesser curvature of the stomach. The gastroduodenal artery arises from the celiac trunk and provides blood supply to the pylorus and proximal duodenum. One of the terminal branches of the gastroduodenal artery is the right gastroepiploic artery. The superior epigastric artery supplies the rectus abdominis muscle and is not intraperitoneal. The superior mesenteric artery arises from the aorta below the celiac trunk and supplies the lower duodenum through the transverse colon; it does not carry the blood supply necessary for design of an omental flap.
A 25-year-old woman who sustained the forearm avulsion shown in the photograph above subsequently underwent reconstruction using a free groin flap based on the superficial circumflex iliac artery. Which of the following best describes the vascular anatomy of this flap?
(A) The superficial circumflex iliac artery arises directly from the external iliac artery in approximately 85% of patients
(B) The superficial circumflex iliac artery arises from a common trunk, terminally splitting with the superficial inferior epigastric artery in approximately 70% of patients
(C) The superficial circumflex iliac and superficial inferior epigastric arteries have separate origins in approximately 40% of patients
(D) The superficial circumflex iliac artery is generally found approximately 1 cm below the inguinal ligament in approximately 70% of patients
The correct response is Option C.
The free groin flap is typically an axially patterned flap that receives its vascularity by the superficial circumflex iliac artery, which arises from the common or superficial femoral artery and then traverses laterally, parallel to the inguinal ligament, typically 2 to 3 cm inferior to the ligament. Although it provides excellent thin soft-tissue coverage of cutaneous defects and is associated with minimal donor site morbidity, especially in women, its use is limited by potential variations in vascular anatomy, as shown in the illustration below.
In 45% to 50% of persons the superficial circumflex iliac artery and superficial inferior epigastric artery arise from a common trunk, as shown in the figure on the left. In contrast, 40% to 45% of persons have a superficial circumflex iliac artery and superficial inferior epigastric artery that arise from separate origins, as shown in the figure on the right. The middle figure demonstrates a large superficial circumflex iliac artery without a superficial inferior epigastric artery, which is present in 10% to 15% of persons. In patients being considered for reconstructive procedures using the free groin flap, vascular anatomy can be determined preoperatively using Doppler ultrasonography.
In addition to its usefulness in coverage of cutaneous defects, as shown in the postoperative photograph below, the free groin flap can also be deepithelialized and transferred as soft-tissue fill in patients with Romberg’s disease or hemifacial microsomia.
A 28-year-old man is brought to the emergency department 30 minutes after he sustained avulsion injuries to the nondominant left hand when it became caught in a motor vehicle fanbelt. Physical examination shows amputation of the index finger at the level of the proximal interphalangeal joint as well as a 2 x 1-cm area of soft-tissue loss. Replantation of the amputated digit is performed, and the resulting 2 x 1-cm soft-tissue avulsion volar defect is covered with an arterialized venous flow-through flap with overlying skin interposed as a vein graft in the arterial repair. Which of the following is the most likely early complication of this flap procedure?
(A) Arterial thrombosis
(B) Congestion of the flap
(C) Failure of the replantation
(D) Hematoma from vessel leak
(E) Loss of flap due to infection
The correct response is Option B.
Venous flow €‘through flaps (VFTFs) are unusual but are gaining acceptance for certain kinds of hand and finger wounds. The ideal site for coverage with a VFTF is a long and narrow defect needing thin soft tissue. VFTFs typically become congested in the first week and then decongest over the following two weeks as they revascularize from the wound bed. VFTFs cannot reliably transfer composite tissue such as bone and tendon or cover a wide defect such as an entire palm. Because VFTFs do not bring in vascularization to the wound bed as well as classic flaps, they are not indicated in radiated or potentially infected wound beds. A small defect such as the 2-cm defect needing coverage during the replantation of the finger in the scenario described is the ideal candidate for this flap.
When compared with simple vein grafts, VFTFs are not associated with increased rates of arterial thrombosis, failure of replantation, or hematoma. Although VFTFs are more susceptible to infection than typical flaps, congestion of the flap with superior epidermolysis is a much more likely complication.
A 9-year-old girl is evaluated for scar revision after sustaining a laceration of the left cheek that was repaired in the emergency department 2 years ago. Examination shows a 4 × 0.7-cm scar that is pale, flat, and wide in appearance. It has an oblique orientation between the oral commissure and zygomatic arch. W-plasty is considered. Which of the following is the most likely outcome of the W-plasty when compared with linear closure in this patient?
A) Decreased initial wound tension
B) Decreased procedural time
C) Increased contracture of the wound
D) Increased removal of healthy tissue
The correct response is Option D.
The W-plasty was first described by Borges in 1953. The repair involves a regular pattern of interdigitating triangular advancement flaps. This repair allows for the scar to have an accordion-like effect secondary to the broken line configuration. The W-plasty and geometric broken line closure (GBLC) techniques are commonly used for scar revisions and are best indicated for scars that cross the relaxed skin tension lines (RSTL) to redirect portions of the scar. Because of the flexibility these scars have, they are also indicated over convex or concave surfaces.
Compared with linear closure, the W-plasty will have decreased contracture of the wound because of the interrupted orientation of the scar. Even though a portion of the final closure will go against the RSTLs, W-plasties can be designed to orient a significant portion along the RSTLs. Because of the many triangular flaps made and repaired, it takes significantly longer to perform a W-plasty repair. The main disadvantage of the W-plasty and GBLC procedures is the need to remove a significant amount of healthy tissue on either side of the scar to be revised, which can lead to increased wound tension and the need for significant undermining.
Which of the following interventions is most appropriate to improve the viability of an ischemic skin flap?
(A) Apply medicinal leeches to the flap
(B) Apply nitroglycerin paste to the flap
(C) Elevate the affected area
(D) Ensure adequate fluid resuscitation
(E) Perform hyperbaric oxygen therapy
The correct response is Option D.
The initial 24-hour period is critical to flap viability. In cases of compromised arterial inflow, steps that can be taken to improve arterial inflow are of primary concern. Ensuring adequate postoperative fluid resuscitation is paramount. This ensures adequate cardiac output and optimizes tissue perfusion.
Medicinal leeches are indicated for venous congestion and would have questionable value in an ischemic setting. Although hyperbaric oxygen therapy and elevation may both have beneficial effects in this setting, they are less appropriate than fluid resuscitation. Some clinicians will use 2% nitroglycerin ointment to ischemic areas every four to six hours or silver sulfadiazine cream twice daily. Either of these techniques is believed to be useful in reducing the risk and extent of full-thickness skin loss but would probably not be as important as ensuring adequate hydration.
A 26-year-old woman is evaluated for burns on the dorsum of the right hand. After serial debridement is performed, the patient has exposed extensor tendons, wrist capsule, and superficial radial nerve. A pedicled groin flap is planned for coverage. Which of the following vessels is most likely to supply arterial blood to the groin flap?
A) Deep circumflex iliac
B) Deep external pudendal
C) Lateral femoral circumflex
D) Superficial circumflex iliac
E) Superficial inferior epigastric
The correct response is Option D.
Although all of these vessels supply flaps in the region of the lower abdominal wall, groin, and thigh, the superficial circumflex iliac artery (SCIA) is the dominant pedicle for free or pedicled, fasciocutaneous groin flaps. The long axis of the flap is centered over a line parallel and 3 cm inferior to the inguinal ligament, with a maximum reliable width of 10 cm. The flap is harvested from lateral to medial, beginning caudad to the posterior iliac spine and extending across the sartorius muscle to femoral vessels. To improve the reliability of the flap, Scarpa’s fascia should be incorporated with the flap laterally, and dissection must continue below the sartorius fascia, as the deep circumflex iliac artery (DCIA) courses between the deep investing fascia of the sartorius and Scarpa’s fascia. The base of the flap can be tubed to improve wound care and allow for closure of most of the donor site.
A 68-year-old man who underwent thoracic fusion is evaluated because of
exposed spinal hardware. Physical examination shows a loss of soft tissue and an
exposed hardware cage at the T2 level. There is no sign of infection. Coverage
with a paraspinous muscle flap is planned. Which of the following is the Mathes
and Nahai classification for this flap?
A) I
B) II
C) III
D) IV
E) V
The correct response is Option D.
Paraspinous muscle flaps are considered the “workhorse” of spinal reconstruction and are
useful for the coverage of exposed hardware and the obliteration of dead space. The
paraspinal muscles are classified as Type IV flaps with multiple segmental pedicles. The
dominant pedicle of the paraspinous muscle flap consists of segmental perforating vessels
arising from the posterior intercostal vessels. The minor pedicle includes lateral row
perforators arising from the posterior intercostal arteries.
REFERENCES:
1. Inglesby DC, Young ZT, Alshareef M, et al. Paraspinous muscle flaps for the treatment of
complex spinal wounds. Spine. 2020;45(9);599-604. doi:
10.1097/BRS.0000000000003341
2. Zenn MR, Jones G, eds. Reconstructive surgery: anatomy technique and clinical
applications. Quality Medical Publishing. St. Louis, Missouri; 2012: 758-776.
A 24-year-old man presents with a burn contracture of the third web space of the hand. A jumping man (five flap) plasty is planned. In this technique, the final position of the central flap is achieved through which of the following techniques?
A) 45-degree transposition
B) 60-degree transposition
C) 75-degree transposition
D) V-Y advancement
E) Y-V advancement
The correct response is Option E.
In the jumping man or five flap plasty, the central flap is advanced through a Y to V method where the tip of the V is advanced into an incision made in the opposing tissue. There are different modifications to this technique for local flap lengthening of flexion contractures. Traditionally, the lateral limbs are designed with 60-degree angles to the central limb and the opposing limbs are designed more obtusely to prevent ischemia at the base. This type of reconstruction requires laxity of the surrounding skin and is therefore most often employed in places like the medial canthus, web spaces of the feet and hands, or the axilla.
A V-Y advancement is commonly used in pressure ulcer repair where the base of the V is advanced into the defect to create a Y. This is the opposite of what one is trying to achieve in a jumping man plasty. Transpositions of 75, 60, and 45 degrees are all different variations of z-plasties and are utilized in this local rearrangement, but the central flap is advanced, not transposed/rotated.
A 45-year-old male fitness instructor has squamous cell carcinoma of the oral cavity requiring reconstruction with a soft-tissue free flap. The patient is very concerned about maintaining all muscular function at the flap donor site. To address the patient’s concern, which of the following fasciocutaneous flaps should be used for reconstruction to minimize muscular donor site morbidity?
a. Anterolateral thigh flap
b. Deep inferior epigastric artery perforator flap
c. Medial sural artery perforator flap
d. Parascapular flap
e. Profunda artery perforator flap
The correct response is Option D.
The benefit of perforator flaps over traditional musculocutaneous flaps is the ability to preserve muscle at the donor site. Depending on perforator anatomy, it can either traverse between surrounding myofascial units requiring no muscle sacrifice, or alternatively pass through the muscle substance requiring division of a small amount of muscle to liberate the flap. The anterolateral thigh (ALT) or deep inferior epigastric artery perforator (DIEP) flaps have variable perforator anatomy containing either septal or muscular perforators, or both within the same flap. The profunda and medial sural artery perforator flaps have vessels that pierce the adductor magnus and gastrocnemius muscles, respectively. Of the options listed, only the parascapular flap consistently has a septal perforator located between the teres major, teres minor, and the triceps.
Reference(s)
- Zenn and Jones. Reconstructive Surgery: Anatomy, Technique and Clinical Applications. 1st ed. Boca Raton, Florida: CRC Press; 2012:150.
- Wei and Mardini. Flaps and Reconstructive Surgery. 1st ed. Philadelphia, PA: Elsevier Health Sciences; 2009: 326.
Immediately after undergoing reconstruction of a wound of the dorsal aspect of the hand using a reverse radial forearm flap, a patient has marked venous congestion of the flap. There is no hematoma visible under the flap. Which of the following is the most appropriate management?
(A) Increasing the temperature of the hand
(B) Elevation of the hand
(C) Intravenous infusion of heparin
(D) Application of leeches to the flap
(E) Anastomosis of an outflow vein
The correct response is Option E.
When harvesting a reverse island flap such as the reverse radial forearm flap, the surgeon should always attempt to preserve an outflow vein, which will be necessary for drainage of the flap if the reverse flow venous system does not function adequately. Most patients exhibit only mild venous congestion, and leeches can be applied to drain the flap sufficiently and thus preserve it. However, any patient who has immediate onset of marked venous congestion in which the cause is not obvious (ie, kinking of the pedicle or hematoma under the flap) should undergo immediate anastomosis of an outflow vein to decompress the flap.
Conservative measures such as increasing the temperature of the hand, elevating the extremity, or infusing heparin intravenously will ultimately fail in a patient with marked venous congestion requiring immediate operative treatment.
A 54-year-old man has a nonhealing wound of the lateral aspect of the right ankle (shown) three months after he underwent open reduction and internal fixation of a fracture. Physical examination shows exposed bone at the base of the wound but no evidence of deep infection. Which of the following flap procedures is most appropriate for closure of this patient=s defect?
(A) Bilateral V-to-Y advancement flaps
(B) Dorsalis pedis fasciocutaneous flap
(C) Extensor digitorum brevis muscle flap
(D) Flexor digiti minimi muscle flap
(E) Lateral calcaneal flap
The correct response is option E.
The most appropriate procedure to close this defect is a lateral calcaneal flap, which has an axial pattern based on the lateral calcaneal artery, a terminal branch of the peroneal artery. This flap is very reliable, even in older patients, and lateral calcaneal artery patency and flow can be determined by preoperative Doppler examination. The donor site is usually skin grafted. (See photographs below.) Other acceptable options include reverse sural flap and free tissue transfer.
Bilateral V-to-Y advancement would be difficult in this patient because there is edema and inflammation associated with a chronic wound. The dorsalis pedis fasciocutaneous flap would reach this defect but has significant donor site morbidity and should be reserved for situations in which other options are not available. The flexor digiti minimi muscle flap is lateral on the foot but is not able to reach the lateral ankle. The extensor digitorum brevis muscle flap has a large arc of rotation but requires sacrifice of the dorsalis pedis artery.
A 52-year-old man with a 10-year history of intravenous drug use is evaluated for right groin pseudoaneurysm. He has a history of right groin reconstruction with a local sartorius flap. After vascular reconstruction, he is left with an exposed vascular conduit in need of stable coverage. The local groin tissues are indurated and stiff. The rectus femoris muscle is rotated to provide coverage. Which of the following lower extremity function deficits is most likely in this patient?
A) Inability to abduct the thigh
B) Inability to extend the knee
C) Inability to flex the ipsilateral hip
D) Weakened extension of the knee
E) No functional deficit
The correct response is Option D.
The rectus femoris muscle is the most superficial and central of the quadriceps extensor muscle group. It is a bipennate muscle that extends from the ilium to the patella and is surrounded by the vastus lateralis and vastus medialis muscles. The rectus femoris acts as an extensor of the knee, specifically powering the terminal 15 to 20 degrees of knee extension. It is also a powerful flexor of the hip. Recent studies have shown that the use of this muscle is effective for groin reconstruction. Mild, isolated deficits are observed although there is no clinical significance of this deficit.
A 45-year-old man is evaluated 2 weeks after open reduction and internal fixation of an extra-articular fracture of the distal tibia because of wound dehiscence. Physical examination shows exposed hardware and a 5 × 3-cm open wound above the medial malleolus. After thorough debridement, hardware removal, and placement of an external fixator, the wound is closed with a perforator propeller flap based on a posterior tibial artery perforator. During dissection and inset, the flap becomes progressively swollen and blue, with brisk capillary refill noted for the entire length of the flap. Which of the following is the most appropriate next step in management?
A) Application of nitropaste
B) Free flap salvage
C) Postoperative leech therapy
D) Proximal perforator dissection to source vessel
E) Observation
The correct response is Option D.
This patient has an open wound in the distal third of the tibia closed with a propeller flap based on a perforator from the posterior tibial artery. The most common complications associated with this type of reconstruction are venous congestion and partial flap loss. If congestion is encountered during flap elevation, it is essential to dissect the perforator all the way back to the named source vessel to release all fascial attachments and any areas of potential constriction or tethering. This would be the first strategy to improve venous outflow during flap dissection. The venae comitantes accompanying the perforator are very thin-walled and susceptible to kinking, especially when flap inset requires a 180-degree rotation.
Propeller flaps are island fasciocutaneous flaps based on a single dissected perforator. They are termed “freestyle” because the design of the flap is determined intraoperatively based on the dissection of the perforator, which has variable anatomy. Ideal perforators are greater than 0.5 mm in diameter and pulsatile. Perforator flaps of the lower extremity should be designed longitudinally based on directional blood flow. Most published series report greater than 90% flap survival with an 8 to 10% rate of complications. If tension or kinking still exists after proximal perforator dissection, microsurgical venous supercharging would be the next course of action, if possible. De-rotating the flap and placing it back into the donor site as a delay procedure can be used as a last resort; however, vascular delay is traditionally used to augment the arterial inflow of a flap by allowing the choke vessels to open and organize the flow in an axial fashion. The flap remains susceptible to venous congestion when it is rotated for inset after the delay as well.
A small amount of decreased venous drainage is expected with most perforator flaps; however, it is generally mild, not progressive, and confined to the distal tip of the flap. This venous insufficiency can be observed and will generally resolve in the early postoperative period. In this case, the congestion was noted early during flap dissection along the full length of the flap. For severe early venous congestion, observation is not appropriate.
Leech therapy is often used to relieve venous congestion of flaps and replanted parts postoperatively if additional venous outflow cannot be established surgically. Abandoning further surgical efforts to plan for leeching would not be advised as an initial course of action.
The traditional reconstructive algorithm for reconstruction of distal one-third defects recommends free tissue transfer. The advent of perforator propeller flaps allows for reconstruction with available like tissue that does not involve microsurgery. Free flap reconstruction would generally be the plan following complete flap loss, but it would not be the next step in management of venous congestion.
Acute venous insufficiency should not be managed with nitropaste therapy.
The direct vascular supply to the arm flap shown is which of the following arteries?
A) Posterior interosseous
B) Posterior radial collateral
C) Profunda brachial
D) Recurrent radial
Correct answer is option B.
Flaps require preservation of the defined arterial and venous supply. Regional flaps can be based distally or proximally. The lateral arm flap was initially described by Song and popularized by Matloub, et al. and Katsaros, et al. This flap has considerable application in reconstruction of the upper extremity. It can be harvested from the same extremity; it has thin, pliable skin; and it can be innervated. The lateral arm flap can also include a segment of vascularized humerus or a segment of vascularized triceps tendon. The flap can also be segmentally contoured for hand defects. The lateral arm free flap is based on the posterior radial collateral artery, which is a branch of the profunda brachial artery. A reversed pedicled lateral arm flap can also be performed. This reverse flap is based on the radial recurrent artery. The superior ulnar collateral artery is the dominant pedicle of the medial arm flap. The medial arm flap is also useful for upper extremity coverage, but there are significant variations in the superior ulnar collateral artery which makes this flap a less-than-optimal choice for microvascular surgical reconstruction. The posterior interosseous artery is the dominant blood supply of the posterior interosseous artery flap. The posterior interosseous artery flap is also used for reconstruction of the hand because it has thin, pliable skin. As a pedicle flap, it can cover the wrist and extend to the first web space. Use of the posterior interosseous flap can compromise motor nerves to the extensor carpi ulnaris or extensor digiti quinti.
A 54-year-old man is scheduled for correction of a defect on the back 1 week after undergoing resection of a 3 × 3-cm recurrent sarcoma. The skin was closed primarily during the procedure, but skin necrosis and wound breakdown occurred. History includes radiation therapy to the spine for soft-tissue sarcoma 2 years ago. Physical examination shows a 5 × 5-cm defect in the mid back at the level of T10 with exposed spinous processes. Which of the following is most appropriate to achieve complete wound closure?
A ) Latissimus dorsi flap
B ) Rectus abdominis free tissue transfer
C ) Split-thickness skin graft
D ) Trapezius muscle flap
E ) Wide undermining with primary reclosure
The correct response is Option A.
The latissimus dorsi flap would allow for the mobilization of sufficient skin and muscle to close the defect in the patient described. The latissimus dorsi muscle is a Mathes-Nahai Type V flap, with the main blood supply from the thoracodorsal artery and vein, and secondary segmental pedicles from the posterior intercostal and lumbar perforators. The latissimus dorsi insertion onto the humerus can be divided to provide further mobilization of the flap. To close the defect, the flap can be used as a €œturnover flap, € with its blood supply based medially on the secondary pedicles. It can also be transposed and advanced on its main blood supply. If needed, interposition vein grafts can be used to extend the vascular pedicle. The flap has a very well-defined anatomy with few anatomical variations, and its harvest is fairly straightforward. It has found tremendous use in reconstructing defects of the scalp, lower extremity, breast, and chest wall.
A free rectus abdominis muscle flap could be performed, but recipient vessels in this area are not readily available. There have been reports of utilizing posterior intercostal perforators as recipient vessels for microvascular anastomosis, but this is an option best reserved as a last resort. Split-thickness skin grafting over a previously irradiated wound bed with exposed bone is not likely to heal. A trapezius muscle flap will not reach the level of T10. Wide undermining is a poor choice because this would lead to further devascularization of previously irradiated skin. Reclosure of the skin primarily is likely to occur under significant tension and would be prone to further necrosis and wound breakdown.
Which of the following structures provides motor innervation to the gracilis free muscle flap?
(A) Anterior branch of the obturator nerve
(B) Femoral nerve
(C) Inferior branch of the superior gluteal nerve
(D) Medial femoral cutaneous nerve
(E) Median sural nerve
The correct response is Option A.
The anterior branch of the obturator nerve provides motor innervation to the gracilis free muscle flap. This nerve branch courses between the adductor longus and adductor brevis tendons to innervate the gracilis muscle.
The femoral nerve innervates the rectus femoris muscle at the level of the thigh, while the inferior branch of the superior gluteal nerve supplies motor innervation to the tensor fascia lata. The medial femoral cutaneous nerve, which is a branch of the femoral nerve, supplies sensory innervation to the medial thigh flap. The median sural nerve is found below the knee and courses parallel to the lesser saphenous vein.
A 62-year-old man is diagnosed with osteosarcoma involving the mandible. Microsurgical reconstruction with a free osseocutaneous flap using iliac bone is planned. The vascular pedicle to this flap is which of the following?
A) Deep circumflex iliac vessels
B) Deep inferior epigastric vessels
C) Superficial circumflex iliac vessels
D) Superficial femoral vessels
E) Superficial inferior epigastric vessels
The correct response is Option A.
The deep circumflex iliac artery (DCIA) arises from the lateral aspect of the external iliac artery. From its takeoff point, it travels toward the anterior superior iliac spine (ASIS) between the transversalis fascia and transversus abdominis muscle. Just medial to the ASIS, it gives off an ascending branch which supplies the internal oblique muscle. Lateral to the ascending branch, the DCIA courses through the transversalis fascia along the inner lip of the iliac crest, where it lies in the line of fusion between the iliacus and transversalis fascia, and supplies the iliac crest bone.
The deep inferior epigastric vessels supply transverse rectus abdominis myocutaneous (TRAM) and deep inferior epigastric artery perforator (DIEP) flaps. The superficial circumflex iliac vessels supply the groin flap. The superficial inferior epigastric vessels supply the superficial inferior epigastric artery (SIEA) flap, which comprises the skin and subcutaneous tissue only of the lower ipsilateral hemi-abdomen. The superficial femoral vessels supply flaps such as the sartorius muscle flap.
A 59-year-old man comes to the office for follow-up examination three weeks after undergoing left total knee replacement. Physical examination shows a draining sinus on the distal aspect of the knee. Surgical removal of the hardware and flap reconstruction are planned. Which of the following is the dominant pedicle to the muscle flap that is most appropriate for reconstruction?
(A) Anterior tibial artery
(B) Ascending branch of the medial circumflex femoral artery
(C) Medial sural artery
(D) Perforating branch of the distal superficial femoral artery
(E) Proximal branches of the posterior tibial artery
The correct response is Option C.
The muscle flap best suited to reconstruct this defect is a medial head of gastrocnemius muscle rotation flap. Its dominant pedicle is the medial sural artery, which is a branch of the popliteal artery.
The ascending branch of the medial circumflex artery is the dominant pedicle to the gracilis flap, whereas the minor pedicles are perforating branches of the distal superficial femoral artery. A proximally based gracilis flap would not have the arc of rotation to adequately cover the knee. A distally based flap would require a delay procedure and is not the best choice for this defect.
The lateral sural artery is the dominant blood supply to the lateral head of the gastrocnemius, which is smaller, and, therefore, not as well suited for coverage of large patellar defects such as this one.
The soleus is based off the proximal two branches of the posterior tibial artery, branches of the proximal popliteal, and branches of the peroneal artery. It is used for reconstruction of defects of the middle third of the lower extremity and does not have an arc of rotation sufficient enough to cover this defect.
According to the Mathes-Nahai classification of muscle and musculocutaneous flaps, which of the following is a type I flap?
(A) Gluteus maximus
(B) Gracilis
(C) Latissimus dorsi
(D) Sartorius
(E) Tensor fascia lata
The correct response is Option E.
The tensor fascia lata, gastrocnemius, and vastus lateralis muscle flaps have a type I vascular pattern consisting of one dominant pedicle. These muscles can be used as rotation flaps for regional reconstruction or as free tissue for transfer.
Type II muscle flaps have one dominant pedicle and several minor pedicles; examples include the abductor digiti minimi, gracilis, and soleus. In type III muscle flaps, such as the gluteus maximus, rectus abdominis, and serratus, there are two dominant vascular pedicles. The extensor hallucis longus, sartorius, and tibialis anterior muscle flaps have a type IV vascular pattern, with multiple segmental vascular pedicles entering along the course of the muscle belly. Type V muscle flaps, such as the latissimus dorsi and pectoralis major, have one dominant pedicle and secondary segmental pedicles, which provide a significant source of muscle circulation.
A 48-year-old man has infected hardware 4 weeks after undergoing spinal fusion. The neurosurgeon washes out the wound and requests consultation for coverage of the defect. In the operating room, the plastic surgeon notes that coverage with a paraspinous muscle flap is not possible, as the muscle has been heavily debrided by the neurosurgeon. Use of a reverse latissimus dorsi flap is planned. These two flaps share an arterial blood supply from which of the following arteries?
A) Circumflex scapular
B) Posterior intercostal
C) Superior gluteal
D) Thoracodorsal
E) Transverse cervical
The correct response is Option B.
The paraspinous muscle is supplied by the posterior intercostal artery; this is the same vessel that supplies the reverse latissimus dorsi flap. For a midline spinal defect, it is unlikely that these vessels are damaged; however, this is possible in large oncologic resections or traumatic injuries.
The circumflex scapular artery supplies multiple flaps that are used for reconstruction, including the scapular and parascapular flaps. The transverse cervical artery supplies the trapezius muscle flap. The superior gluteal artery supplies the gluteus maximus muscle. The thoracodorsal artery is the main arterial supply of the latissimus muscle.
When used for breast reconstruction, both the superior and the inferior gluteal artery perforator flaps utilize a vascular bundle that is a terminal branch of which of the following arteries?
A ) Deep circumflex iliac
B ) External iliac
C ) Femoral
D ) Internal iliac
E ) Pudendal
The correct response is Option D.
Both the superior and inferior gluteal arteries are terminal branches of the internal iliac artery. They pass out of the pelvis above and below the piriformis muscle, supplying the upper and lower halves of the muscle, respectively. As the superior gluteal artery passes the greater sciatic foramen, it divides into superficial and deep branches. The deep branch travels between the gluteus medius muscle and the iliac bone. The superficial branch goes on to supply the gluteus muscle and the overlying skin territory. The superficial branch of the gluteal artery nourishes the fat and skin in the musculocutaneous flaps in this region. These perforating vessels can be separated from the underlying muscle and fascia and form the basis for the S-GAP flap, which allows maximal preservation of the donor site muscle and other underlying structures while creating a reliable skin €“soft-tissue flap. Two to three perforators are usually found arising from this vessel, with a pedicle length between 3 cm and 8 cm.
A 50-year-old man is scheduled to undergo mandibulectomy with floor of mouth resection for cancer. An osteocutaneous radial forearm free flap is being considered. Which of the following is the strongest contraindication to performing this flap?
A) Abnormal Allen test
B) Anterior mandibular tumor location
C) Defect length of 8 cm
D) History of prior radiation
E) Lack of availability of ipsilateral neck muscles as recipients
The correct response is Option A.
The osteocutaneous radial forearm free flap (OCRFFF) is based on the radial artery, one of the major sources of blood to the hand. An abnormal Allen test is a sign of insufficient ulnar artery blood flow and would be a major contraindication to utilizing this flap.
While the quantity of bone available for transfer from the radius is thought of as a limitation of this flap, many authors have reported safely harvesting up to 10 cm or more of bone length. The thickness of the bone is also a limitation and it is recommended that no more than one-third to one-half of the bone thickness be harvested to avoid an iatrogenic radial fracture, even when the remaining bone is prophylactically plated and/or bone grafted. Because of this, osseointegrated implants for dental restoration can rarely be performed. The bone component of the OCRFFF is well vascularized and associated with high rates of union and can tolerate osteotomies needed for anterior mandible restoration as well as be used for closing irradiated wounds. An advantage of this flap, in addition to providing a thin, pliable skin paddle, is that it has a long pedicle length that can often reach the inspilateral transverse cervical blood vessels or contralateral neck blood vessels without the need for interposition vein grafting.
A healthy 40-year-old man comes to the office because of an injury to his finger. Examination shows a 4 × 3-cm, full-thickness defect over the proximal interphalangeal (PIP) joint of the right index finger. The joint capsule and extensor tendons are exposed. No sign of infection is noted. Coverage with an arterialized venous free flap from the forearm is planned. Which of the following is the main disadvantage of using this flap in reconstruction?
A ) Difficult flap monitoring
B ) High incidence of total flap failure
C ) Inability to transfer flap with nerve and/or tendon
D ) Limited supply of donor sites
E ) Technically demanding flap harvest
The correct response is Option A.
Arterialized venous free flaps are thin fasciocutaneous flaps that are useful in reconstructing defects of the hand. The main advantage of an arterialized venous flap is the ease of harvesting a thin flap without the need to sacrifice a major artery at the donor site. The design of venous flaps is very easy because of direct visualization of the venous plexus through the thin overlying skin. There is no limitation of the donor site because it is possible to find the venous network at any location of the body. They can be harvested as composite flaps, including nerve and tendon flaps. Despite many advantages, arterialized venous flaps are not commonly selected as the first choice for microsurgical reconstruction. Venous congestion is an expected part of the flap’s postoperative course, and this makes monitoring the flap especially difficult as compared with other conventional flaps. Signs of vascular insufficiency and characteristic edema and congestion of venous flaps are difficult to differentiate. In cases of venous congestion, flap viability can be monitored only by palpating the pulse or by laser Doppler probe analysis. Though venous congestion is common, the ultimate success rate of arterialized venous flaps is similar to that of conventional flaps, with total flap loss a rare occurrence.
A 50-year-old woman has wound breakdown in the lumbosacral region after spinal instrumentation, as shown in the photograph on the left. The superior aspect is closed with local paraspinal muscle advancement. The lower aspect is closed with a musculocutaneous V-Y advancement flap, as shown in the photograph on the right. Which of the following Mathes/Nahai classifications is most appropriate for this flap?
A) Type I
B) Type II
C) Type III
D) Type IV
E) Type V
The correct response is Option C.
The Mathes and Nahai classification system is useful for predicting clinical applicability of various muscle and musculocutaneous flaps. With proper knowledge of the location and variation of muscle blood supply, the surgeon can safely determine the extent of muscle transposition during surgery. Five patterns of muscle circulation have been described. These patterns are based on the following relationships between the muscle and its vascular pedicle:
The regional source of the vascular pedicle(s) entering the muscle
Pedicle size
Number of vascular pedicles
Location of the pedicle in relation to muscle origin and insertion
The angiographic patterns of intramuscular vessels
The gluteal V-Y advancement flap used in the clinical scenario described is a Mathes/Nahai Type III flap. Type III muscle flaps demonstrate two large, independent vascular pedicles arising from separate regional arteries. Other Type III muscles include the rectus abdominis and serratus anterior. Angiographic studies have shown equal filling of the intramuscular vascular system with either pedicle injection. Type III muscle flaps can be based on either pedicle and can be split to preserve muscle function. In this particular ambulatory patient, only the superior half of the gluteal muscle (based on the superior gluteal artery) was used in order to preserve lower gluteal function.
Type I muscles have a single dominant pedicle. Examples include the gastrocnemius, rectus femoris, and tensor fascia lata flaps.
Type II muscle flaps demonstrate one or more large vascular pedicles near the muscle origin and several small pedicles entering the muscle belly distally. Commonly used muscle flaps in this group include the gracilis, soleus, and trapezius. The minor pedicles are typically divided to allow maximal muscle transposition. Division of the minor pedicles typically has little effect on muscle flap survival, but poorly planned musculocutaneous flaps may suffer distal skin ischemia if not planned appropriately. This vascular pattern is the most common pattern observed in anatomical studies of human cadaveric muscle.
Type IV muscles demonstrate segmental vascularization along the entire length of the muscle. The sartorius and tibialis anterior muscles are the most clinically relevant muscles that display this type of pattern. The segmental nature of the blood supply severely limits the ability to transpose these muscles and therefore the utility is limited.
Type V muscles display one dominant vascular pedicle near the muscle origin and multiple segmental pedicles near the muscle insertion. The latissimus and pectoralis major muscles demonstrate this vascular pattern. Angiographic studies demonstrate that the intramuscular vasculature can be supplied by either the dominant or segmental pedicles. As a result, the flaps can be elevated on either vascular system.
A 70-year-old woman has a circular defect 18 cm in diameter on the parietal aspect of the scalp after excision of squamous cell carcinoma. The pericranium has been removed with the scalp tissue. Adjuvant radiation therapy is planned beginning 4 to 6 weeks after surgery. Which of the following is most appropriate for coverage of the defect?
A) Latissimus dorsi muscle free flap with split-thickness skin graft
B) Primary closure after galeal scoring
C) Split-thickness skin grafting
D) Temporary reconstruction with a split-thickness skin graft followed by a rotation-advancement flap after scalp tissue expansion
The correct response is Option A.
The latissimus dorsi muscle free flap with split-thickness skin grafting can be used to reconstruct large scalp defects in a single stage, allowing the patient to proceed with radiation therapy after recovery from surgery.
While temporary reconstruction with a split-thickness skin graft followed by definitive reconstruction with a rotation-advancement flap after tissue expansion is feasible for defects approaching 50% of the scalp surface area, this choice is inappropriate, as skin grafts usually have poor take on bare calvarium devoid of pericranium, particularly when treated with radiation. Radiated tissues are more difficult to expand, and their expansion is associated with a high rate of complications. Primary closure is usually only feasible in scalp defects less than 3 cm in diameter, even with galeal scoring to increase scalp flap length and reduce wound tension. Graft take can be improved by burring the bone down to the bleeding diploic space, but this technique results in unstable bone coverage, particularly in the setting of postoperative radiation.
Which of the following is NOT an indication for Z-plasty?
(A) Adjusting soft-tissue contour
(B) Dispersing linear scars
(C) Lengthening linear scar contractures
(D) Preventing burn scar contractures
The correct response is Option D.
The Z-plasty is a fundamental plastic surgery technique that involves the elevation and interposition of two equal, interposed triangular skin flaps. This procedure can be used to improve soft-tissue contour via reorientation of skin, realign scars within the lines of minimal tension, and lengthen linear scar contractures. However, it is not performed for prevention of burn scar contractures.
Which of the following muscles comprise the boundaries of the triangular space in which the circumflex scapular artery is located?
(A) Infraspinatus, latissimus, and teres minor
(B) Latissimus, long head of the triceps, and teres major
(C) Latissimus, teres minor, and teres major
(D) Long head of the triceps, supraspinatus, and teres major
(E) Long head of the triceps, teres major, and teres minor
The correct response is Option E.
The boundaries of the triangular (or omotricipetal) space, in which the circumflex scapular artery is located, are comprised of the long head of the triceps muscle laterally, the teres major muscle inferiorly, and the teres minor muscle superiorly. The circumflex scapular artery is a branch of the subscapular artery and emerges from the triangular space to supply blood to the parascapular flap.
The quadrangular space can be found immediately lateral to the triangular space. This space is defined by the surgical neck of the humerus, lateral head of the triceps muscle, teres major muscle, and teres minor muscle. The axillary nerve and posterior humeral circumflex artery pass through this space.
The other muscles listed above can be identified in the region of the shoulder and trunk but do not define the triangular space.
A 65-year-old man undergoes operative removal of a basal cell carcinoma at the junction of the upper cheek and temporal region, followed by coverage of the resultant 10 _ 5-cm defect with a submental myocutaneous flap. This flap derives its blood supply from a branch of which of the following arteries?
(A) Facial
(B) Inferior thyroid
(C) Lingual
(D) Superior thyroid
(E) Transverse cervical
The correct response is Option A.
The submental flap is a myocutaneous flap that is useful in head and neck reconstruction. This flap provides a contour, color, and tissue texture that is suitably matched to the face. The flap is elevated below the level of the platysma muscle and includes the submental artery and vein, which are direct branches of the facial artery and vein. The flap can be transposed to cover defects in the lower and central thirds of the face and into the inferior aspect of the upper third of the face.
The submental artery is a consistent branch of the facial artery and gives off one or two cutaneous perforators to the submental skin. The submental artery runs in relation to the anterior belly of the diagastric muscle. Of the choices listed, the facial artery is the most superior branch of the external carotid artery. The lingual artery provides the blood supply to the tongue, the superior thyroid and inferior thyroid arteries provide the blood supply to the thyroid gland, and the transverse cervical artery gives off a descending branch, which provides the blood supply to the trapezius muscle.
A 27-year-old man has a large segmental defect of the humerus. Reconstruction using an osteocutaneous free flap from the lower leg is planned. A portion of which of the following muscles is most appropriately included with the bone to protect the pedicle and improve reliability of the skin island?
A ) Extensor digitorum longus
B ) Flexor hallucis longus
C ) Gastrocnemius
D ) Peroneus longus
E ) Tibialis posterior
The correct response is Option B.
The most appropriate muscle is the flexor hallucis longus.
The fibular free flap is a workhorse flap for reconstruction of large segmental bone defects. The vascular supply of this flap comes from the peroneal artery. A large segment of bone can be harvested, consisting of the majority of the fibula with the exception of the proximal 6 cm at the fibular head and the distal 6 cm near the ankle joint. The fibular flap can be harvested with a skin paddle on the lateral aspect of the leg, based on perforators through the lateral intermuscular septum or via the muscle. The pedicle is located adjacent to the flexor hallucis longus muscle in the deep posterior compartment of the leg. Inclusion of a cuff of the flexor hallucis longus muscle can be performed to protect the pedicle and add bulk to the reconstruction if necessary. A composite flap of fibula and the entire flexor hallucis longus muscle has been described. The lateral portion of soleus muscle can also be included in the fibula free flap if desired.
The extensor digitorum longus muscle is in the anterior compartment of the leg. The gastrocnemius muscle is in the posterior compartment of the leg and is more superficial. The peroneus longus muscle is in the lateral compartment of the leg. The tibialis posterior muscle is in the deep posterior compartment of the leg and is located along the interosseous membrane.
A 24-year-old man is brought to the emergency department after sustaining a degloving injury of the long, ring, and little fingers of the dorsal, nondominant left hand in a high-speed, rollover motor vehicle collision. Following debridement, the patient has obvious open proximal interphalangeal (PIP) joints of each of these fingers. Which of the following is the most appropriate management of these defects?
A ) Cross-finger flap coverage
B ) Full-thickness skin grafting from the groin
C ) Pedicle lateral arm flap coverage
D ) Reverse radial forearm flap coverage
E ) Split-thickness skin grafting from the thigh
The correct response is Option D.
Pedicled fascial flaps to the hand provide an excellent reconstructive option in cases of exposed tendon, joint, or bone where soft-tissue coverage is needed. They provide thin, broad, well-vascularized coverage and a gliding surface for tendons and joints. The pedicled reverse radial forearm flap is the most appropriate option for this defect. The cross-finger flap may be an option for a single digit, but not in the large zone-of-injury described. The groin flap, although reliable, is bulky and requires the attachment of the upper extremity to the trunk, followed by division and insetting of the flap at a later time. The pedicle lateral arm flap cannot reach the fingers. The reverse radial forearm flap may be harvested with skin or simply as a fascial flap. Skin grafting, either full- or split-thickness, would not be appropriate coverage for exposed joint surfaces.
A 53-year-old woman comes to the office with an exposed vascular graft in the left groin caused by postoperative wound infection. After operative debridement, a proximally based sartorius muscle flap is transferred to cover the graft. Several days after surgery, it is evident that the distal portion of the muscle flap is necrotic. This most likely occurred because the sartorius muscle demonstrates which of the following Mathes-Nahai types of vascular pattern?
A)
B)
C)
D)
E)
The correct response is Option D.
The sartorius muscle demonstrates a Mathes-Nahai Type IV vascular pattern with multiple segmental vascular pedicles. For this reason, it is important to preserve as many segmental pedicles as possible when transferring this flap. The sartorius flap is usually transferred as a distally based flap, and not a proximally based flap as presented in the clinical scenario. When based proximally, it is necessary to ligate multiple segmental pedicles to achieve an adequate arc of rotation, and this can lead to flap necrosis. When based distally, it is often necessary to divide 1 to 2 segmental pedicles superiorly to allow an adequate arc of rotation, but this usually does not compromise the flap. If there is any concern regarding flap perfusion, the pedicles can be temporarily clamped before division to assess the effects of pedicle ligation.
Examples of muscle flaps with the other Mathes-Nahai types of vascular pattern include the following:
Type I – tensor fascia lata
Type II – gracilis
Type III – gluteus maximus
Type V – latissimus dorsi
A 22-year-old man has undergone multiple debridements of a wound of the right hand since he sustained a gunshot wound six days ago. Physical examination shows a significant soft-tissue defect and a 4-cm segment of bone loss from the third metacarpal. A radial forearm osteofasciocutaneous flap procedure for simultaneous reconstruction of the soft-tissue and skeletal defects is planned. Which of the following portions of the radius is the most appropriate site for harvesting the cortical bone graft?
(A) Radial aspect, between the brachioradialis and pronator teres insertions
(B) Radial aspect, between the brachioradialis insertion and flexor pollicis longus origin
(C) Radial aspect, between the pronator teres insertion and flexor pollicis longus origin
(D) Ulnar aspect, between the brachioradialis and pronator teres insertions
(E) Ulnar aspect, between the pronator teres insertion and flexor pollicis longus origin
The correct response is Option A.
When raising a radial forearm osteofasciocutaneous flap, cortical bone should be harvested from the radial aspect of the radius between the brachioradialis and pronator teres muscle insertions. A cuff of the flexor pollicis longus to the radius is maintained to preserve the periosteal vessels. A small cuff of periosteum is maintained on both sides of the radial vessels. All of the other optional donor sites are anatomically not appropriate. A segment up to 10 cm in length and up to 40% of the cross €‘sectional area of the radius may be harvested. The superficial branch of the radial nerve, running adjacent to the brachioradialis, is at risk and is sometimes sacrificed.
After undergoing radical mastectomy of the left breast for management of breast carcinoma, a 40-year-old woman with obesity is scheduled for delayed reconstruction using a transverse rectus abdominis myocutaneous (TRAM) flap. Which of the following is the most likely sequela of a delayed TRAM flap procedure?
(A) Increased blood flow to the deep inferior epigastric artery
(B) Increased diameter of the superior epigastric artery
(C) Increased pressure within the superior epigastric vein
(D) Increased quantity of choke vessels
(E) Increased quantity of myocutaneous perforators
The correct response is Option B.
A delay procedure is appropriate for any patient considering TRAM flap reconstruction who has risk factors for flap loss, including obesity, a smoking history, a previous history of radiation therapy, or large volume requirements. A delayed procedure is typically performed in the outpatient setting and involves ligation of the deep and superficial inferior epigastric vessels, eliminating blood flow through the deep inferior epigastric artery. Studies of patients who have undergone this procedure demonstrated increased diameter and flow volume of the superior epigastric artery. The vascular structures within the flap are also dilated during the delay procedure. The choke vessels connect adjacent vascular regions and have been shown in animal studies to achieve maximum dilation 48 to 72 hours after surgery. Cell hypertrophy has been demonstrated within the walls of the choke vessels.
A 27-year-old woman is evaluated for a traumatic wound to the left heel that she sustained when she was attacked by a shark 6 days ago. Physical examination shows a 5 × 5-cm soft-tissue defect with exposed bone. Reconstruction with a sensate flap taken from the instep region is planned. Which of the following nerves provides innervation to this flap?
A) Calcaneal
B) Lateral femoral
C) Medial plantar
D) Superficial peroneal
E) Sural
The correct response is Option C.
The nerve supply to the medial plantar artery flap is the medial plantar nerve.
The medial plantar artery flap is a sensate flap that can be used for coverage of heel defects. The flap incorporates tissue from the medial instep of the foot in a non–weight-bearing area, and can be transposed posteriorly to allow for coverage of heel defects. This flap provides durable plantar glabrous skin that can allow for weight bearing.
The flap is based on the medial plantar artery, which arises from the posterior tibial artery. A branch of the medial plantar nerve providing sensation to the instep of the foot can be harvested with the flap, allowing for preservation of sensation in the reconstructed heel.
The medial plantar artery flap can also be raised as a sensate free flap, with anastomosis of the medial plantar nerve to a nerve at the recipient site.
The calcaneal nerve provides native sensory innervation to the heel.
The lateral femoral cutaneous nerve provides sensation to the anterolateral thigh flap.
The superficial peroneal nerve provides motor innervation to the lateral leg.
The sural nerve provides sensation to the lateral side of the foot.
A 47-year-old woman is brought to the emergency department immediately after sustaining a laceration of the left thumb while cutting pastrami with an industrial meat slicer. Physical examination shows loss of skin and subcutaneous tissue on the volar aspect of the thumb from the metacarpophalangeal joint flexion crease to the interphalangeal joint flexion crease. The flexor tendon and digital neurovascular bundles are exposed in the wound base. Perfusion and sensation of the tip of the thumb are intact. Which of the following is the most appropriate management?
A) Full-thickness skin grafting
B) Reconstruction with a first dorsal metacarpal artery flap
C) Reconstruction with a thenar flap
D) Reconstruction with a volar advancement (Moberg) flap
E) Split-thickness skin grafting
Correct answer is option B.
The tissue requirements are determined by the nature of the wound bed and functional requirements for the site of reconstruction. Skin grafts are inappropriate in the face of exposed tendon or tendon sheath. Advancement of the volar tissue of the thumb is useful for distal thumb defects. Dissection of the skin, subcutaneous tissue, and neurovascular bundles from the underlying tissue and flexion of the interphalangeal joint allow for distal movement of the tissue for thumb pulp pad coverage. This approach would not be useful for a volar defect at the level of the proximal phalanx. The first dorsal metacarpal artery flap could be used to provide coverage of this area of the thumb. The skin and subcutaneous tissue can be elevated from the dorsum of the index finger to the level of the middle phalanx. The first dorsal metacarpal artery is included with this tissue. If a sensory flap is desired, branches of the radial nerve within the flap can be preserved or coapted to sensory nerves at the recipient site. A thenar flap would be appropriate for providing coverage for fingertips but not this region of the thumb.
A 32-year-old male athlete sustains a contact burn to the right foot. Serial debridement results in exposure of the medial aspect of the first metatarsophalangeal joint. A photograph is shown. Which of the following is the most appropriate option for definitive wound management?
A) Amputation of the great toe
B) Bony debridement and primary closure
C) Coverage with a fasciocutaneous free flap
D) Local tissue rearrangement
E) Negative pressure wound therapy
The correct response is Option C.
The most appropriate option to obtain definitive wound coverage is a fasciocutaneous free flap harvested from outside the zone of injury. Amputation is not indicated when the majority of the great toe is viable. In addition, this would be highly morbid for this young athlete. Negative pressure wound therapy alone would promote healing by secondary intention, but with an exposed joint this would likely result in an unstable wound. Local tissue rearrangement in this area results in marked donor site morbidity. Bony debridement and primary closure may lead to a healed wound, but functional morbidity would be high in this athlete.
What is the theoretic gain in length achieved by performing a Z-plasty with angles of 75 degrees?
(A) 25%
(B) 50%
(C) 75%
(D) 100%
The correct response is Option D.
The Z-plasty is a technique in which pairs of triangular transposition flaps are created adjacent to a scar and then transposed across the scar, increasing the length of the central limb and changing the orientation of the scar. This technique can be used in patients undergoing burn reconstruction to lengthen linear scar contractures, disperse linear scars, and realign scars within the lines of minimal tension. The theoretic gain in length correlates directly with the angle and length of the flap limbs. The actual gain in the length of the central axis will be decreased by 30% to 50% because of the contractile properties of skin.
The theoretic gain achieved with each angle is illustrated in the table below.
A 60-degree Z-plasty is performed most commonly because it produces a significant gain in length while minimizing the tension of closure.
An otherwise healthy 55-year-old man is diagnosed with a soft-tissue sarcoma of his mid-anterior leg. Neoadjuvant radiation therapy is performed, followed by wide local excision. A superficial circumflex iliac perforator-based flap is planned for reconstruction of the 10 × 5-cm defect. Which of the following is the main advantage of this flap over a radial forearm flap?
A) Ability to neurotize the flap
B) Ease of flap harvest
C) Length of pedicle
D) Lower donor site morbidity
E) Thickness of flap
The correct response is Option D.
The main advantage of the superficial circumflex iliac perforator-based (SCIP) flap over the radial forearm flap (RFF) is the improved donor site outcome. The SCIP flap can be primarily closed in most cases, whereas most RFF donor sites need a split skin graft to get closure. Additionally, the groin donor site is in a relatively hidden area compared with the RFF. The SCIP flap is a more difficult flap to raise compared with the RFF, and also has a smaller diameter and length of pedicle. Both flaps are known for being raised as thin flaps and can potentially be neurotized, with the SCIP utilizing an intercostal nerve branch, whereas the RFF uses the lateral and/or medial antebrachial cutaneous nerve(s).
A 45-year-old man is evaluated for unstable plantar scar 3 years after undergoing skin grafting for a traumatic amputation at the tarsometatarsal joints. A photograph is shown. An anterolateral thigh flap is planned for coverage of the resultant plantar defect. Which of the following coaptations is most likely to allow for sensory recovery of the flap?
A) Lateral femoral cutaneous nerve to a deep peroneal nerve branch
B) Lateral femoral cutaneous nerve to a superficial peroneal nerve branch
C) Lateral femoral cutaneous nerve to a tibial nerve branch
D) Medial femoral cutaneous nerve to a deep peroneal nerve branch
E) Medial femoral cutaneous nerve to a tibial nerve branch
The correct response is Option C.
The medial femoral cutaneous nerve provides sensation to the anteromedial, not the anterolateral, thigh flap.
Achieving durable results after reconstruction of defects on the weight-bearing surface of the foot is challenging for two main reasons: flap donor sites (other than the medial plantar artery flap) do not have the specialized skin structures of the sole of the foot and are thus less durable than native foot skin; a transferred flap will always be less sensate than native, uninjured plantar foot skin. Flaps are thus more vulnerable to trauma because they cannot feel, and they are less able to tolerate trauma because they lack the native characteristics of plantar skin.
Coapting the sensory nerve of a flap to the native sensory nerve of the recipient area will allow a flap to recover some sensibility, and thus it may be more able to tolerate weight bearing. The sensory innervation to the anterolateral thigh flap is the lateral femoral cutaneous nerve. The sensory innervation to the plantar midfoot is the medial plantar nerve, a terminal branch of the tibial nerve.
The superficial peroneal nerve provides sensation to the dorsal foot.
The deep peroneal nerve provides sensation to the dorsal foot.
A 24-year-old right-hand-dominant male construction worker is evaluated because of a right dorsal thumb abscess that is treated with debridement and administration of antibiotics. A photograph of the residual defect is shown. Which of the following is the most appropriate method for reconstruction in this patient?
A ) Coverage with a muscle flap
B ) Coverage with a skin flap
C ) Full-thickness skin grafting
D ) Negative pressure wound therapy
E ) Split-thickness skin grafting
The correct response is Option B.
The residual defect includes exposed extensor tendon without paratenon. This fact, combined with the need for flexion at the interphalangeal joint and avoidance of contracture, as well as the likely need for future tenolysis, makes a skin flap the most appropriate option for reconstruction. In the scenario described, a first dorsal metacarpal artery pedicled skin flap is used to reconstruct the thumb defect with the need for back grafting of the donor site. This provides the best combination of low donor-site morbidity, the ability to provide stable soft-tissue coverage over exposed tendon without paratenon, and the competitive advantage of being relatively easy to re-elevate for subsequent procedures, if needed.
A muscle flap could be used to reconstruct the defect but would not be optimal due to the increased donor site morbidity from muscle sacrifice, as well as the increased difficulty in re-elevation versus a skin flap over tendon.
Healing by secondary intention, with or without topical negative pressure wound therapy, will certainly result in extensive contracture as well as an increased time to heal. This will impact the patient’s outcome both in terms of his ability to return to work as a construction worker as well as limitations on his functional range of motion.
Skin grafting, whether split- or full-thickness, is not a reliable option in this patient because of the exposed tendon without paratenon. It is important to note that this is a classic contraindication to skin grafting and therefore leads to a flap-based reconstruction.
Furthermore, skin grafts would lead to increased contraction versus flaps and would be difficult to re-elevate for subsequent procedures.
A 65-year-old woman presents with a malignant melanoma of the right ankle that requires resection resulting in exposed bone. Her thighs are too bulky as donor sites for ankle skin resurfacing. Reconstruction with a free fascio-cutaneous scapular flap is planned. Through which of the following anatomic landmarks will the pedicle for this flap pass?
A) Anterior triangle of the neck
B) Posterior triangle of the neck
C) Quadrangular space
D) Subclavian triangle
E) Triangular space
The correct response is Option E.
The pedicle for the scapular fasciocutaneous flap is the circumflex scapular artery arising from the subscapular system. The circumflex scapular artery travels through the triangular space bordered laterally by the long head of the triceps, the teres minor above and teres major below.
The posterior circumflex humeral vessels travel within the quadrangular space, which is adjacent to the triangular space and is bordered by the teres minor above, teres major below, long head of the triceps medially, and the humerus laterally.
The anterior triangle of the neck is bordered superiorly by the mandible, laterally by the sternocleidomastoid muscle, and medially by the midline of the neck. The contents of the anterior triangle include cranial nerves VII, IX to XII, and the carotid arteries and internal jugular vein.
The posterior triangle of the neck is bordered by the trapezius muscle posteriorly, the sternocleidomastoid muscle anteriorly, and the middle third of the clavicle inferiorly. The posterior triangle of the neck contains the external jugular vein, the brachial plexus, regional lymph nodes, third part of the subclavian artery, as well as the suprascapular vessels and cervical branches of thyrocervical trunk. The posterior triangle of the neck is divided by the inferior belly of the omohyoid muscle into the occipital triangle above and subclavian triangle below.
The subclavian triangle is bounded by the sternocleidomastoid, omohyoid, and the clavicle.
A 20-year-old woman is undergoing evaluation eight months after sustaining a severe degloving injury, including multiple injuries to skin and tendons, to the dorsal aspect of the left hand. At the time of injury, extensive wound care was followed by full-thickness skin grafting from the left side of the groin. On current physical examination, the patient has severe contractures and clawing of the metacarpophalangeal joints. The photograph above shows an outline of the flap that is to be used to resurface the dorsal aspect of the hand.
This flap derives its axial blood supply from which of the following arteries?
(A) Deep inferior epigastric artery
(B) Medial femoral circumflex artery
(C) Superficial circumflex iliac artery
(D) Superficial external pudendal artery
(E) Superficial inferior epigastric artery
The correct response is Option E.
The flap depicted in the photograph is the superficial inferior epigastric artery (SIEA) flap, also known as the Shaw flap. This flap derives its axial blood supply from the superficial inferior epigastric (SIE) artery, one of three cutaneous arteries supplied by the common femoral artery. The SIE artery arises from the intersection of the inguinal ligament and the femoral artery, then courses superiorly and laterally toward the anterior axillary line.
The SIEA flap is typically transferred as a pedicled flap, but fasciocutaneous free tissue transfer has also been described. This flap is recommended for coverage of wounds of the hand and forearm because it lies in a relatively higher position on the torso than the groin flap; this allows for improved mobility of the shoulder while placing the elbow in a comfortable, flexed position while the flap matures. To confirm the pedicle pattern, Doppler ultrasonography can be performed prior to elevation of the flap. A photograph of the inset of the flap is shown above.
The superficial circumflex iliac artery provides the axial blood supply to the groin flap. This artery also originates from the femoral artery and travels parallel to the inguinal ligament, approximately 1 cm deep to the ligament.
Although the deep inferior epigastric artery supplies the rectus muscle on its deep surface, it does not supply the skin of the abdomen directly; instead, perforators emerge from the deep inferior epigastric artery and course through the rectus muscle to supply blood to the skin of the abdomen. This vascularity allows the skin and muscle to be harvested for free flap transfer.
The superficial ex
Between what muscles the lumbar artery flap perforator pedicle passes:
A. Semispinalis and Longissimus
B. Erector spinae and Quadratus lumborum
C. Iliocostalis and Longissimus
D. Erector spinae and Semispinalis
Correct answer is option B.
The lumbar artery perforator flap is an option for autologous breast reconstruction. Within the flap, the cluneal nerve can be harvested for sensation. The flap is based off of the lumbar artery perforator (L4), which runs lateral to the erector spinae muscle, with the quadratus lumborum muscle on the other side. The perforator does not run in between the other muscles listed.
- Stillaert FBJL, Opsomer D, Blondeel PN, Van Landuyt K. The lumbar artery perforator flap in
breast reconstruction. Plast Reconstr Surg. 2023;151(1):41-44.
doi:10.1097/PRS.0000000000009782 - Peters KT, Blondeel PN, Lobo F, van Landuyt K. Early experience with the free lumbar artery
perforator flap for breast reconstruction. J Plast Reconstr Aesthet Surg. 2015;68(8):1112-1119
A 75-year-old man with a history of renal transplantation presents with a rapidly growing squamous cell carcinoma involving his anterior scalp and forehead. A photograph is shown. Wide excision results in a 20 × 20-cm defect with exposed calvarium. Which of the following flaps is most appropriate for coverage of this wound?
A) Anterolateral thigh free flap
B) Gracilis free flap
C) Lateral arm free flap
D) Radial forearm free flap
E) Rectus abdominis free flap
The correct response is Option A.
The anterolateral thigh (ALT) free flap (shown) is the only option listed with the requisite tissue characteristics, size, and pedicle length necessary to repair a defect of this size and location. The ALT flap has rapidly become a first-line option for covering large or irregular head and neck defects. It is an extremely versatile flap with chimeric options allowing for multiple skin paddles, muscle bulk (vastus lateralis) if needed for dead space obliteration, as well as bone (iliac crest) for midface or small mandibular defects. The tissue thickness is well suited for large scalp defects. Flaps as large as 35 × 25 cm have been described, although defects larger than 10 to 12 cm in width generally require skin grafting the donor site. Pedicle lengths of 12 to 16 cm have been described, which is often long enough to reach the upper neck if necessary.
The radial forearm free flap is an excellent option in many cases, providing a pedicle length up to 18 to 20 cm with maximal dimensions up to 12 × 30 cm. A major criticism of this flap is the poor cosmesis of the donor site and lack of subcutaneous tissue necessary to match the surrounding cutaneous defect. The lateral arm flap based on the radial collateral artery is useful for smaller defects in the head and neck but is limited in this situation by a short pedicle (6 cm) and smaller skin paddle (6 × 12 cm).
Muscle flaps covered with skin grafts have also been described for scalp coverage. When necessary, a latissimus dorsi flap is a great option for near total scalp coverage. With the examples listed here, the gracilis flap is too narrow (5 to 6 cm) with too short a pedicle (medial femoral circumflex, 7 cm). While the pedicle for the rectus free flap (deep inferior epigastric, 8 to 10 cm) might be long enough in this situation, the muscle is not big enough (6 cm wide) to cover the defect.
A 24-year-old man has defects over the dorsal aspect of the proximal phalanges of the index and long fingers after sustaining a grinder injury. The extensor tendon of the index finger is denuded of peritenon over a 1cm diameter area extending from the metacarpophalangeal joint to the proximal interphalangeal joint. A skin graft is planned to reconstruct the defect over the long finger. Which of the following flaps is most appropriate to reconstruct the defect over the index finger?
A) Adipofascial turndown
B) Cross-finger
C) Dorsal thumb metacarpal transposition
D) Reverse posterior interosseous artery
E) Reverse radial forearm
Correct answer is option A.
Small, dorsal defects of the fingers can be reconstructed via a number of local flaps; as in many other parts of the body, adipofascial turnover flaps have been developed for the upper extremity, hand, and fingers. Advantages of these flaps include almost limitless donor sites, single stage reconstruction, and minimal donor site morbidity. For coverage of dorsal digital defects, adipofascial turnover flaps are designed with the base of the flap proximal to the defect. The flap itself is designed to be 2 to 4 mm wider than the skin defect with a base to length ratio of 1:1.5 to 1:3. A longitudinal incision over the center of the flap allows dissection of the flap from the overlying skin. The adipofascial flap is then elevated from proximal to distal from the underlying paratenon. Elevation stops approximately 0.5 to 1 cm proximal to the defect to create the base of the flap; the flap is then turned over into the digital defect and covered with a split thickness skin graft (see the figure below). Given the damage to the adjacent long finger, a cross finger flap would not be possible. A transposition flap from the dorsal thumb may suffice for first web resurfacing but will not adequately reach the dorsal index finger. Both the posterior interosseous artery and radial-artery based flaps are capable of resurfacing sizable defects on the hand and fingers; however, the added morbidity of harvesting these flaps does not warrant their use when a more suitable local flap is available.
The direct vascular supply to the arm flap shown is which of the following arteries?
(A) Posterior interosseous
(B) Posterior radial collateral
(C) Profunda brachial
(D) Recurrent radial
(E) Superior ulnar collateral
The correct response is Option B
Flaps require preservation of the defined arterial and venous supply. Regional flaps can be based distally or proximally. The lateral arm flap was initially described by Song and popularized by Matloub, et al. and Katsaros, et al. This flap has considerable application in reconstruction of the upper extremity. It can be harvested from the same extremity; it has thin, pliable skin; and it can be innervated. The lateral arm flap can also include a segment of vascularized humerus or a segment of vascularized triceps tendon. The flap can also be segmentally contoured for hand defects. The lateral arm free flap is based on the posterior radial collateral artery, which is a branch of the profunda brachial artery. A reversed pedicled lateral arm flap can also be performed. This reverse flap is based on the radial recurrent artery. The superior ulnar collateral artery is the dominant pedicle of the medial arm flap. The medial arm flap is also useful for upper extremity coverage, but there are significant variations in the superior ulnar collateral artery which makes this flap a less-than-optimal choice for microvascular surgical reconstruction. The posterior interosseous artery is the dominant blood supply of the posterior interosseous artery flap. The posterior interosseous artery flap is also used for reconstruction of the hand because it has thin, pliable skin. As a pedicle flap, it can cover the wrist and extend to the first web space. Use of the posterior interosseous flap can compromise motor nerves to the extensor carpi ulnaris or extensor digiti quinti.
To reconstruct a traumatic soft-tissue defect of the hand, a lateral arm fasciocutaneous flap is chosen for free tissue transfer. The vascular pedicle for this flap is located between which of the following structures?
A) Brachioradialis and brachialis
B) Lateral head of the triceps and biceps
C) Lateral head of the triceps and the brachialis
D) Lateral head of the triceps and the extensor carpi radialis longus
E) Lateral head of the triceps and the humerus
The correct response is Option C.
The lateral arm flap is a reliable fasciocutaneous flap used for reconstruction of small to medium size soft-tissue defects of the forearm and hand. It provides thin tissue of excellent quality and a satisfactory aesthetic outcome with the ability for primary closure of the donor site.
The dominant pedicle is the posterior radial collateral artery. This vessel originates from the radial collateral artery which is a branch of the brachial artery in the upper arm and emerges between the brachialis muscle anteriorly and the lateral head of the triceps posteriorly to supply the skin and soft tissue of the lateral arm.
In addition, the anatomic relationships between the vascular pedicle and radial nerve are important to understand when dissecting this flap. The radial nerve courses posterior to the humerus before wrapping around the lateral aspect of the humerus from posterior to anterior. The antebrachial cutaneous nerve of the forearm branches from the radial nerve to join the vascular pedicle (posterior branch of radial collateral artery). This cutaneous nerve can be preserved with careful dissection and helps to identify the radial nerve proximally during flap elevation. Segmental perforating vessels emerge within the septum separating the triceps and brachialis muscles.
A 40-year-old man sustains burns to 35% of his total body surface area, including the neck, chest, axillae, and upper extremities. After subsequent skin grafting, a right anterior axillary dome scar contracture develops. The patient is scheduled to undergo revision of the scar using Z-plasty. Which of the following lateral limb angles will result in a theoretical 75% gain in central limb length?
A) 30 degree
B) 45 degree
C) 60 degree
D) 75 degree
E) 90 degree
A 40-year-old man sustains burns to 35% of his total body surface area, including the neck, chest, axillae, and upper extremities. After subsequent skin grafting, a right anterior axillary dome scar contracture develops. The patient is scheduled to undergo revision of the scar using Z-plasty. Which of the following lateral limb angles will result in a theoretical 75% gain in central limb length?
A) 30 degree
B) 45 degree
C) 60 degree
D) 75 degree
E) 90 degree
The correct response is Option C.
The traditional standard Z-plasty consists of at least three incisions of equal length (two limbs and one central incision) and two angles of equal degree. Ideally, the central incision runs parallel to the long axis of the scar, or the scar itself may be completely excised with the fusiform defect acting as the central incision.
The resultant subcutaneous triangular skin flaps are transposed with each other such that the new, central incision lies perpendicular to the original central incision. After closure, the scar is reoriented along the limb incisions, and the new central incision lies within relaxed skin tension lines. The length of the original scar also increases after a Z-plasty, which is a useful characteristic when a surgeon desires release of a scar contracture, as in this specific example. In general, as the central incision lengthens (given a constant angle), so does the resultant scar. Additionally, as the angles between the limbs increase (given a constant limb length), so does the resultant scar.
A 79-year-old woman comes to the office because of a large scalp defect following Mohs micrographic surgery for basal cell carcinoma. A photograph of the defect (left) and a rotation flap designed to cover the defect (right) are shown. At the completion of the procedure, a large “dog ear” is noted at the pivot point of the flap. Which of the following is the most appropriate next step in management?
A) Burrow triangle
B) Compression
C) Direct excision
D) Staged advancement
E) Observation
The correct response is Option E.
The most appropriate next step in management is observation. A Burrow triangle would not sufficiently address this deformity and is not necessary. Compression and staged advancement are not necessary, as the deformity resolves spontaneously. The temptation to excise should be resisted, as most of these ?dog ears? resolve over time. Photographs immediately after the procedure (left) and 5 months later (right) are shown.
Excision would only increase the length-to-width ratio and compromise blood supply to the flap. If the contour abnormality is unacceptable to the patient after some time has passed, then excision at a later time can be performed. The need for this is exceedingly rare.
A 48-year-old man is brought to the emergency department after being involved in a high-speed motorcycle collision. Physical examination shows comminuted fractures of the left radius and ulna. A photograph of his wounds is shown. After debridement of the necrotic tissue, the brachial vessels and median nerve are exposed. Microsurgical techniques are not available. Which of the following is the most appropriate choice for tissue coverage in this patient?
A ) Groin flap
B ) Lateral arm flap
C ) Posterior interosseous artery flap
D ) Radial forearm flap
E ) Split-thickness skin graft
The correct response is Option B.
The vascular supply of the lateral arm flap is from the posterior radial collateral artery, a terminal branch of the deep brachial artery. This artery communicates distally with the ulnar artery, allowing the flap to be raised in a distally based fashion, as it was for the patient in this item. For most adult patients, a 12 × 6-cm flap can be harvested and still allow for primary donor site closure. The major extremity vessels are not disturbed with the harvest of this flap.
A groin flap would be difficult to mobilize sufficiently to reach the defect shown. It would also require leaving the arm attached to the torso for several weeks for vascular ingrowth prior to division and inset.
The posterior interosseous artery flap is based on the communication between the anterior and posterior interosseous arteries just proximal to the distal radioulnar joint. Its pedicle can be used in a distally based fashion to allow for coverage of defects of the hand and wrist. It cannot reach to cover defects at the elbow.
A radial forearm flap has two major disadvantages. It will remove a major vessel to a wrist and hand that is needed to heal a severe injury. It will also expose the radius fracture, requiring secondary flap reconstruction of the donor site. Split-thickness skin grafting is inappropriate to place over an exposed nerve, as sensitivity and pain would be expected to persist after healing. In addition, a skin graft would suffer secondary contraction, which would impair elbow extension.
A 16-year-old boy develops a severe left first web space contracture 8 months after undergoing skin grafting for a soft-tissue avulsion injury. At the time of contracture release, a pedicled fasciocutaneous flap is planned for coverage of the soft-tissue defect. On the basis of the preoperative markings for the flap in the photographs shown, the flap pedicle is located between which of the following muscles?
a. Brachioradialis and extensor carpi radialis longus
b. Brachioradialis and flexor carpi radialis
c. Extensor digiti minimi and extensor carpi ulnaris
d. Extensor digiti minimi and the extensor digitorum communis
e. Extensor digitorum communis and extensor carpi radialis brevis
The correct response is Option C.
The photograph illustrates the markings for a reverse posterior interosseous artery (PIA) flap. The reverse PIA flap is a thin, pliable fasciocutaneous flap that can provide reliable coverage of soft-tissue defects involving the dorsal hand, metacarpophalangeal joints, and first web space. Some surgeons report success using this flap for coverage of palmar wounds and soft-tissue injuries of the thumb as well.
Perfusion of the flap is based on retrograde flow through the posterior interosseous artery, which sends septocutaneous perforators to the overlying skin. The axis of the flap can be marked corresponding to a line between the lateral epicondyle and the radial aspect of the ulnar styloid. The location of the posterior interosseous artery pedicle is between the extensor digiti minimi and the extensor carpi ulnaris. Retrograde perfusion through the flap relies on an intact communication of the PIA with the dorsal branch of the anterior interosseous artery, which is present in nearly all cases. This anastomosis is located 2 cm proximal to the radial aspect of the ulnar styloid; therefore, it corresponds to the pivot point of the flap. One of the advantages of this flap is that it does not require sacrifice of a major arterial source of blood to the hand.
The other responses do not correctly describe the location of the PIA. Of note, the interval between the brachioradialis and the flexor carpi radialis represents the location of the radial artery fasciocutaneous flap pedicle.
Reference(s)
- Acharya AM, Bhat AK, Bhaskaranand K. The reverse posterior interosseous artery flap: technical considerations in raising an easier and more reliable flap. J Hand Surg Am. 2012;37(3):575-582.
- Gavaskar AS. Posterior interosseous artery flap for resurfacing posttraumatic soft tissue defects of the hand. Hand (N Y). 2010;5(4):397-402.
- Wang JQ, Cai QQ, Yao WT, Gao ST, Wang X, Zhang P. Reverse posterior interosseous artery flap for reconstruction of the wrist and hand after sarcoma resection. Orthop Surg. 2013;5(4):250-254.
A 56-year-old man presents to the emergency department with fever and neck pain 2.5 weeks after undergoing posterior cervical spine fusion. Clinical examination shows peri-incisional edema and erythema. CT scan shows a deep posterior fluid collection. The orthopedic surgery team plans surgical treatment with debridement and washout and consults the plastic surgeon for obliteration of an anticipated dead space. A Mathes and Nahai type II muscle flap is planned for reconstruction. Which of the following arteries is most likely involved in this reconstruction?
A) Circumflex scapular
B) Occipital
C) Thoracoacromial
D) Thoracodorsal
E) Transverse cervical
The correct response is Option E.
The transverse cervical artery is the main pedicle to the trapezius muscle flap (type II muscle), which is particularly suitable for high cervical defects since the paraspinous muscles are of limited size and mobility at this level. The main pedicle of the trapezius flap enters the deep aspect of the muscle approximately 8 cm from the midline at the level of C7. Following identification of the main pedicle, the lateral aspect of the muscle is divided to permit transposition into the defect.
Postoperative wound complications following spinal procedures approach 40% in high-risk patients. Thus, combined reconstructive approaches with orthopedic surgery and neurosurgery are common for management of these complex soft-tissue defects. Key management principles include timely debridement, bony fixation, and dead space obliteration. Therefore, muscle flaps are particularly suitable for reconstruction.
A branch of the occipital artery is the dominant pedicle to the sternocleidomastoid flap, which is not a suitable reconstructive option for coverage of a posterior cervical defect. The circumflex scapular artery is the dominant pedicle to the scapular/parascapular fasciocutaneous (not muscle) flaps. The thoracoacromial artery is the dominant pedicle to the pectoralis major muscle (type V muscle). The thoracodorsal artery is the dominant pedicle to the latissimus dorsi muscle (type V muscle).
A 32-year-old man sustains a burn to his hand, resulting in a first web space contracture. A four-flap Z-plasty is planned for release of the contracture. Which of the following best describes the flap reconstruction for this defect?
The correct response is Option F.
Random pattern flaps are generally classified based on the primary motion of the flap. There are three basic types of tissue movement: transposition, advancement, and rotation. Transposition flaps incorporate noncontiguous skin into a defect by lifting the flap over normal skin for inset into a defect. Advancement flaps recruit adjacent tissue to close a defect via soft-tissue movement in a linear direction. Rotation flaps move adjacent tissue around an axis to close a defect, rotating soft tissue into the defect. Advancement and rotation flaps recruit adjacent lax tissue and move in either a linear or arced motion (respectively) to fill the defect. Transposition flaps recruit noncontiguous tissue, which is lifted over intact soft tissue and placed into the defect. Random pattern flaps lack a defined named arterial vascular supply. Because of their lack of an axial vascular supply, they are subject to dimensional restrictions. In general, they are designed to not exceed a length:width ratio of 2:1. An axial pattern flap is a single pedicled flap that has an anatomically named arterial blood supply running along its long axis. Because of the presence of a named arterial blood supply, axial pattern flaps are not subject to the length:width ratio restrictions that apply to random pattern flaps.
A 44-year-old man presents with a 20-degree extension deformity of his wrist because of burn scarring. Z-plasty for contracture release is planned. Which of the following (A-D) is the most appropriate placement of the central limb for this procedure in this patient?
A) (see image above)
B) (see image above)
C) (see image above)
D) (see image above)
The correct response is Option A.
Z-plasty is a fundamental and common reconstructive technique used to elongate scars or contractures, narrow scars, rearrange tissues into relaxed skin tension lines, camouflage scars, or releasing tension. This is a form of rotation and advancement whereby a central limb of the Z-plasty is drawn parallel to the line of maximal tension, and subsequent limbs are drawn anywhere from 30 to 90 degrees from this. Wider angles give greater scar elongation at the expense of greater transverse tension.
In this scenario, the line of maximum tension is longitudinal, creating an extension deformity. Maximal contracture release will occur with a central limb of the Z-plasty drawn longitudinally.
A 76-year-old woman with a history of left modified radical mastectomy and radiation therapy comes to the office because of a chronic wound of the left axilla associated with limitation of abduction and exposed rib at the wound base. A photograph is shown. Examination of a biopsy specimen excludes malignancy. In addition to appropriate debridement, which of the following is likely to be most effective in achieving wound closure?
A) Adjacent tissue transfer
B) Left latissimus dorsi myocutaneous flap
C) Negative pressure wound therapy
D) Radial forearm fasciocutaneous free flap
E) Split-thickness skin graft
The correct response is Option B.
The best option to achieve wound closure in this patient is an ipsilateral latissimus dorsi myocutaneous flap. For chronic wounds in an irradiated field, the best option is debridement followed by transfer of healthy, nonirradiated tissue. Negative pressure wound therapy is likely to result in a recurrent chronic wound, albeit a clean one. Split-thickness skin graft would be inappropriate in an irradiated wound bed with exposed bone. Autologous fat grafting can help improve the quality of irradiated tissues in the absence of a wound, and some studies have shown promise in the treatment of superficial radiation ulcers; however, this patient has necrotic rib, and following debridement the wound will be deep and large. Although wound management and fat grafting have been shown to promote healing in isolated cases, this approach is not yet an accepted standard of care. Adjacent tissue transfer will employ irradiated tissue, and is thus prone to necrosis, wound breakdown, and recurrent chronic wound formation. A free flap could be an option, but a forearm flap would not have the volume required for the expected defect. In addition, a free flap is more morbid than a local pedicled flap in this elderly patient.
A 48-year-old male presents with a large soft tissue defect of the medial thigh (20x20 cm) following traumatic injury. The defect involves full-thickness loss of skin and subcutaneous tissue, with exposed muscle. The patient is otherwise healthy, with no significant comorbidities. Which of the following is the most appropriate flap for reconstructing this large defect while minimizing donor site morbidity and avoiding the need for microsurgical techniques?
A) Free anterolateral thigh flap
B) Keystone design perforator island flap
C) Rectus abdominis myocutaneous flap
D) Medial gastrocnemius flap
E) Latissimus dorsi myocutaneous flap
The correct answer is B) Keystone design perforator island flap
Explanation:
The keystone design perforator island flap is an ideal option for reconstructing large soft tissue defects, especially when there is no need for microsurgical techniques. The flap is designed to use random fasciocutaneous and musculocutaneous perforators, with an advancement technique that minimizes tension and improves closure. The design allows for excellent aesthetic coverage, especially in areas like the medial thigh, and reduces the need for skin grafting. The inclusion of V-Y advancement flaps at the poles further facilitates closure and minimizes tension.
Rationale for other options:
• A) Free anterolateral thigh flap: While this is a reliable option, it involves microsurgery and a higher donor site morbidity, which could be avoided with the keystone flap in this case.
• C) Rectus abdominis myocutaneous flap: This flap involves harvesting a muscle, which increases morbidity, especially for a defect in the thigh, where a fasciocutaneous flap would be preferable.
• D) Medial gastrocnemius flap: This flap would not be suitable for a defect on the medial thigh as it cannot reach the area effectively, and it involves sacrificing muscle.
• E) Latissimus dorsi myocutaneous flap: Although effective, this flap requires muscle harvesting and a more invasive approach, making it less ideal compared to the keystone flap for this specific defect.
Key considerations for flap design:
The keystone design perforator island flap allows for a well-vascularized coverage of large defects using locally available tissue, preserving the integrity of the surrounding area. The proper design and execution of the flap, along with techniques like V-Y advancement and deep fascial release, optimize the success of the reconstruction while minimizing donor site morbidity.
References:
1. Weinberg M, Heiman AJ, DeSanti R, Lanni MA, Kouwenberg EV, Patel A. Outcomes of the keystone island perforator flap: a systematic review. J Reconstr Microsurg. 2022;38(9):727-733. doi:10.1055/s-0042-1745744
2. Gómez OJ, Barón OI, Peñarredonda ML. Keystone flap: overcoming paradigms. Plast Reconstr Surg Glob Open. 2019;7(3):e2126. doi:10.1097/GOX.0000000000002126
3. Khouri JS, Egeland BM, Daily SD, et al. The keystone island flap: use in large defects of the trunk and extremities in soft-tissue reconstruction. Plast Reconstr Surg. 2011;127(3):1212-1221. doi:10.1097/PRS.0b013e318205f36f
4. Behan FC. The keystone design perforator island flap in reconstructive surgery. ANZ J Surg. 2003;73(3):112-120. doi:10.1046/j.1445-2197.2003.02638.x
A 45-year-old patient undergoes free fibula osteocutaneous flap harvest for reconstruction after head and neck tumor resection. Over time, the patient develops a claw toe. Which of the following is the most likely cause of this deformity?
A. Injury to the extensor hallucis longus
B. Injury to the peroneus longus
C. Contracture of the flexor hallucis longus muscle
D. Injury to the tibialis posterior
E. Injury to the peroneus brevis
Correct answer: C. Contracture of the flexor hallucis longus muscle.
When harvesting a free fibula osteocutaneous flap, the flexor hallucis longus muscle is separated from the fibula bone and preserved. However, because its attachments to the fibula have been divided, contracture of the flexor hallucis longus muscle can develop, resulting in a claw toe over time. If the flexor hallucis longus muscle is harvested with the flap, the patient will be unable to flex the great toe immediately postoperatively.
The extensor hallucis longus, peroneus brevis, peroneus longus, and tibialis posterior muscles are all dissected away from the fibula and could be injured during the dissection. However, this would not result in a claw toe.
References:
1. Ling XF, Peng X. What is the price to pay for a free fibula flap? A systematic review of donor-site morbidity following free fibula flap surgery.
Plast Reconstr Surg. 2012;129(3):657-674.
doi:10.1097/PRS.0b013e3182402d9a
2. Ni Y, Zhang X, Zhang Z, et al. Assessment of fibula flap with flexor hallucis longus’s effect on head & neck tumor patients’ quality of life and function of donor site.
Oral Oncol. 2020;100:104489.
doi:10.1016/j.oraloncology.2019.104489
A 55-year-old male presents with a squamous cell carcinoma of the floor of the mouth requiring surgical resection and reconstruction. The surgical team plans to use a submental flap for reconstruction. During the procedure, the surgeon identifies the submental artery and prepares to harvest the flap. Which of the following structures is NOT typically included in the submental flap based on its arterial supply and anatomical relationships?
A. Mylohyoid muscle
B. Platysma muscle
C. Anterior belly of the digastric muscle
D. Hyoglossus muscle
Correct Answer: D. Hyoglossus muscle
Rationale:
The submental flap is an axial-patterned flap based on the submental artery, a reliable branch of the facial artery. The submental artery runs between the horizontal ramus of the mandible and the submandibular gland, supplying the surrounding structures. The muscles that can be included with the flap are the mylohyoid, platysma, and the anterior belly of the digastric muscle. The submental artery also supplies the submandibular gland, mandible, and cutaneous perforating vessels through the platysma. However, the hyoglossus muscle is not included in this flap or the same anatomic area, as it receives its blood supply from the lingual artery, specifically its sublingual branch. The genioglossus, hyoglossus, and stylohyoid muscles are not part of the submental flap’s vascular territory.
References:
Bertrand B, Honeyman CS, Emparanza A, et al. Twenty-five years of experience with the submental flap in facial reconstruction: evolution and technical refinements following 311 cases in Europe and Africa. Plast Reconstr Surg. 2019;143(6):1747-1758. doi:10.1097/PRS.0000000000005678
Honeyman C, Cebron U, Bradley D, et al. Increasing the reach of the submental artery island flap using the Y-V pedicle lengthening technique: video and technical considerations. Plast Reconstr Surg. 2021;148(5):1121-1124. doi:10.1097/PRS.0000000000008486
