Flaps 01-22 Flashcards
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 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 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.
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 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 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 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 65-year-old woman presents with a 4 x 4-cm elliptical defect on the vertex of the scalp after resection of a trichilemmal cyst. Local advancement flaps are planned for closure with wide undermining. Division of which of the following layers is important during scalp flap advancement?
A) Dermis
B) Galeal aponeurosis
C) Innominate fascia
D) Pericranium
E) Subgaleal fascia
The correct response is Option B.
During a scalp advancement flap, release of the galeal aponeurosis is important, as this layer provides the majority of resistance to scalp advancement. Often scoring of the galea is performed in parallel 1-cm intervals to provide adequate release.
The layers of the scalp include: skin, dense connective tissue, galeal/epicranial aponeurosis, loose areolar connective tissue, and pericranium. Release of the other layers listed is not effective, as they do not provide appreciable resistance. The innominate and the subgaleal fascia are the same layer, otherwise known as the subaponeurotic layer or the loose areolar layer. Release of this layer does not offer appreciable laxity when performing advancement flaps.
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.
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 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 43-year-old man presents for reconstruction of a soft tissue deficit of the antecubital fossa with a reverse lateral arm pedicled flap. Which of the following arteries is the blood supply for this flap?
A) Anterior interosseous
B) Persistent median
C) Posterior interosseous
D) Radial recurrent
E) Ulnar
The correct response is Option D.
Although the lateral arm flap has predominantly been used in free tissue transfer for distant defects based on the posterior radial collateral artery, transfer as a pedicled reverse-flow flap based on the radial recurrent artery has been both anatomically and clinically proven. Occasionally, it is performed with a delay procedure at an intermediate stage.
The anterior and posterior interosseous arteries can provide circulation to perforator flaps. The ulnar artery has been occasionally used for an ulnar artery based fasciocutaneous flap. The persistent median artery passes through the carpal tunnel and runs with the median nerve.
A 10-year-old boy with osteosarcoma is undergoing resection of 8 cm of proximal tibia. Reconstruction with a vascularized bone flap is planned. Which of the following arteries is the primary blood supply for this flap?
A) Anterior tibial
B) Dorsalis pedis
C) Peroneal
D) Popliteal
E) Posterior tibial
The correct response is Option C.
The peroneal artery is adjacent to the fibula. It arises from the tibioperoneal trunk, immediately distal to the takeoff of the anterior tibial artery. It perforates the interosseous membrane. The peroneal artery also gives perforators to the skin of the lower leg. The length of the pedicle is usually short, but can be increased substantially by dissecting the peroneal artery from the fibula and using the distal bone for reconstruction.
The popiteal artery is proximal to the other arteries mentioned. After crossing the knee, it branches into the anterior and posterior tibial arteries. The posterior tibial artery then gives off the peroneal artery.
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 4-year-old girl is evaluated for an axillary skin contracture from a burn. Z-plasty is planned to lengthen the scar in order to improve the contracture. If 45-degree angles are planned, the most likely expected increase in the length of the scar would be which of the following?
A) 25%
B) 50%
C) 75%
D) 100%
E) 120%
The correct response is Option B.
The most likely expected increase in scar length is 50%. A Z-plasty is a technique using two triangular flaps which are interdigitated, producing a gain in length of the central limb placed along the line of contracture. The angles of the Z-plasty range from 30 to 90 degrees. The wider the angles, the greater the lengthening. A 30-degree angle is equal to a 25% increase in length, a 45-degree angle is equal to a 50% increase in length, a 75-degree angle is equal to a 100% increase in length, and a 90-degree angle is equal to a 120% increase in length. The most commonly used angle is 60 degrees, giving a 75% increase in length. This angle is optimal because angles less than 60 degrees may not provide enough lengthening, and angles greater than 60 degrees can produce significant tension inhibiting flap transposition.
A 35-year-old man is brought to the emergency department with a 15-cm open wound on the left hip and thigh after he was involved in an accident while using machinery at a construction site. Much of the skin of the lateral thigh is injured, and exposed bone is noted over the trochanter of the hip. Wound coverage using an anterolateral thigh flap from the right side is planned. When the flap is harvested, which of the following muscles must be identified in order to preserve perforators to the flap?
A) Gracilis
B) Inferior gluteal
C) Sartorius
D) Tensor fascia lata
E) Vastus lateralis
The correct response is Option E.
The anterolateral thigh flap is a versatile coverage tool because of its wide skin island (up to 8 x 25 cm) and long, accessible pedicle (up to 7 cm). The blood supply originates from the lateral femoral circumflex artery descending branch, and sends perforating branches through the vastus lateralis and rectus femoris muscles, and occasionally through the intermuscular septum.
The inferior gluteal muscle, while a common muscle flap, is further posterior and proximal. The tensor fascia lata is more lateral to the anterolateral thigh flap zone, though it also has a blood supply from the lateral femoral circumflex system, as the vessel terminates in the tensor fascia lata. The sartorius is more medial and proximal and has a segmental circulation based on the femoral artery branches. The gracilis is more medially based, and is supplied by the medial femoral circumflex.
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 63-year-old man has a full-thickness scalp defect following resection of a melanoma. Final pathology has confirmed clear margins. Which of the following criteria is an indication for coverage of the defect with a flap instead of a skin graft?
A) Alopecia of the surrounding skin
B) Exposed calvarium
C) Granulation tissue in the base of the wound
D) Intact pericranium
E) Posterior location
The correct response is Option B.
Exposed bone does not provide an adequately vascularized bed for skin graft take. Pericranium, in contrast, can support a skin graft. The presence of granulation tissue is a good sign that the wound bed is adequately vascularized for a skin graft to take. Surrounding alopecia decreases aesthetic concerns associated with reconstructive options that do not support hair growth. Defect location does not significantly affect the need for vascularized coverage.
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 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.
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 55-year-old man who recently underwent a cardiac bypass procedure has a sternal infection that requires debridement. The defect is evaluated, and reconstruction using an omental flap is planned. Which of the following vessels provides the blood supply for this flap?
A) Gastroepiploic
B) Left gastric
C) Right gastric
D) Short gastric
E) Superior mesenteric
The correct response is Option A.
The omental flap is supplied by the gastroepiploic vessels. Common options for sternal wound reconstruction include the pectoralis major, rectus abdominis, latissimus dorsi, and omental flaps. The use of an omental flap for a mediastinal defect was described in the 1970s; however, muscle flaps became a popular choice for reconstruction in the 1980s. Based on the size of the defect, the omental flap can be used with or without a skin graft. The omentum has angiogenic and immunogenic properties that make it ideal for reconstruction of sternal wound infections.
The omentum is based on the left and right gastroepiploic vessels. In order to increase length, the flap can be based on one set of vessels, usually the right gastroepiploic vessels. The left gastroepiploic vessels are a branch of the splenic vessels; the right gastroepiploic vessels are a branch of the gastroduodenal vessels. Harvest can be performed through either an upper abdominal incision, transdiaphragmatic, or laparoscopically. There is a risk of donor site morbidity such as abdominal wound infections or symptomatic hernias.
The superior mesenteric vessels supply the lower part of the duodenum extending to the middle third of the transverse colon, as well as the pancreas. The left and right gastric vessels supply the lesser curvature of the stomach. The short gastric vessels supply a portion of the greater curvature of the stomach and are branches of the splenic vessels. The left and right gastroepiploic vessels supply the greater curvature of the stomach along with the omentum.
A 23-year-old man presents 2 years after sustaining full-thickness burns on the anterior neck. He has undergone tissue expansion and local flap reconstruction of the burn defect. He notes webbing and contracture at the margin of one of the prior flap reconstructions. Three identical 60-degree Z-plasties are planned over a total length of 12 cm. The expected gain in scar length is which of the following?
A) 3 cm
B) 4 cm
C) 6 cm
D) 8 cm
E) 9 cm
The correct response is Option E.
A 60-degree z-plasty lengthens a scar by 75%. If each z-plasty covers 4 cm of scar, each will lengthen the scar by 3 cm, for a total increase of 9 cm. In contrast, a 30-degree z-plasty lengthens an incision by 25%, and a 45-degree z-plasty lengthens an incision by 50%. To prevent undue tension, angles greater than 60 degrees should be avoided.
A 24-year-old man comes to the emergency department because of a dorsal hand injury. Physical examination shows a 6 × 4-cm full-thickness defect with exposed metacarpal bones. A medial sural artery perforator flap for soft-tissue coverage is planned. From which of the following vessels does the vascular pedicle for this flap originate?
A) Anterior tibial
B) Descending genicular
C) Peroneal
D) Popliteal
E) Posterior tibial
The correct response is Option D.
The vascular pedicle for the medial sural artery perforator flap arises from the popliteal vessels.
The medial sural artery flap is a thin, pliable perforator flap that can provide well vascularized soft-tissue coverage, especially for relatively small defects. It is commonly used for head/neck, hand, and lower-extremity defects. The first perforator is frequently found along a line connecting the mid-popliteal area to the medial malleolus at the 8-cm mark from the proximal end. Preoperative planning is facilitated with ultrasound identification of the perforators. Sub-fascial dissection is frequently performed to protect the perforator and blood supply and to allow for a gliding surface for tendon repairs. Donor sites that are narrower than 5 cm can frequently be closed primarily. The main benefit of the medial sural artery perforator flap over an anterolateral thigh flap is the relative thinness of the flap, which can be significant in overweight or obese patients.
A 24-year-old man comes to the office because of an open wound and osteomyelitis of the right elbow after sustaining a fracture of the olecranon during a fall 1 month ago. Use of the lateral arm flap for coverage of the defect is planned. Which of the following is the arterial supply to the lateral arm flap?
A) Medial collateral
B) Posterior radial collateral
C) Posterior ulnar collateral
D) Radial
E) Ulnar
The correct response is Option B.
The posterior radial collateral artery is a branch from the profunda brachial artery, which is off the brachial artery. A second branch is the anterior radial collateral artery but this is variable and of small caliber so does not contribute to the vascular supply. The posterior radial collateral artery interconnects with the radial recurrent artery off the radial artery. This will allow for reverse pedicle design. The middle or medial collateral artery is a branch off the posterior radial collateral artery in 61.5% and off the profunda brachial artery in 38.5%. It can be used as an elongated lateral flap by converting a Y to a V.
The radial, ulnar, and posterior ulnar collateral arteries are not appropriate. The radial artery supplies the radial forearm flap, a fasciocutaneous flap. The ulnar artery supplies a fasciocutaneous flap as well. The posterior ulnar recurrent artery supplies the flexor carpi ulnaris flap, which is a muscle or musculocutaneous flap.
A 73-year-old man comes to the office for evaluation of an 8-cm mandibular defect with commensurate skin loss 6 weeks after sustaining a gunshot wound to the face. Reconstruction with a free fibula composite flap with skin paddle is planned. Which of the following arteries is the most common origin for blood supply to the skin paddle?
A) Anterior tibial
B) Peroneal
C) Popliteal
D) Posterior tibial
E) Sural
The correct response is Option B.
The skin paddle of the free fibula flap receives its vascular supply from the peroneal, posterior tibial vessels, or from both. While a majority (95.8%) of the skin paddles receive their blood supply from the peroneal septocutaneous perforators, a few receive vascular contribution from both peroneal and posterior tibial systems, a few from only the posterior tibial system, and finally, a few from the popliteal artery.
The anterior tibial and sural arteries do not typically contribute to the skin paddle of the free fibula graft.
A 57-year-old man comes to the office because of a rectourethral fistula that developed after he underwent radiation treatment for prostate cancer. Reconstruction with a pedicled muscle-only gracilis flap is performed. From which of the following directions does the medial femoral circumflex artery pedicle enter the gracilis muscle?
A) Anterior
B) Inferior
C) Lateral
D) Medial
The correct response is Option C.
The gracilis muscle is a useful flap for perineal reconstruction. It was first described for use in rectourethral fistula repair by Ryan et al. in 1979. The gracilis muscle is the most superficial of the adductor group and can easily be found in the mid thigh, traversing between the pubic tubercle and medial femoral condyle. Its blood supply is from the profunda femoris as a direct branch or terminal branch of the medial femoral circumflex. There are multiple additional minor pedicles along the muscle’s length (Mathes and Nahai type II). The dominant pedicle enters the muscle approximately a handbreadth below the inguinal crease. It enters the deep aspect of the muscle (ie, from lateral to medial) making dissection of the superficial muscle safe and easy.
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 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 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 35-year-old paraplegic man presents with a 5 × 5-cm pressure ulcer over his left ischium involving the skin, subcutaneous tissue, and bone. After debridement, a gluteal rotation flap is planned for closure. Compared with a transposition flap, which of the following is the most significant benefit of using a rotation flap for coverage of this patient’s wound?
A) Ability to reuse flap for future surgery
B) Decreased recurrence rate
C) Improved pressure relief
D) Improved scar placement
E) Improved vascularity
The correct response is Option A.
Ischial pressure ulcers can be one of the most difficult wounds for which to achieve long-term coverage and success. The best outcomes arise from multidisciplinary care teams that focus on pressure alleviation (both perioperative and chronic), nutrition, smoking cessation, muscle spasm management, and vigilant observation. Despite best efforts, ischial pressure ulcers still have up to a 70% recurrence rate. Because of high recurrence rates, surgical planning needs take potential future wounds into consideration. Large rotation or advancement flaps have the benefit of being able to be re-rotated or re-advanced, whereas transposition flaps do not, and can make future surgery more difficult. With good surgical planning, rotation and transposition flaps would not have a difference in vascularity, scar placement, pressure relief, or recurrence rates.
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 45-year-old man is brought to the emergency department 2 hours after sustaining an avulsion injury to the dorsum of the left hand in a motorcycle accident. Physical examination shows complete loss of the dorsal skin and exposure of the extensor tendons in the dorsal hand with no viable peritenon. Reconstruction of the defect with a lateral arm free flap is planned. Which of the following arterial pedicles will supply this flap?
A) Anterior interosseous
B) Inferior cubital cutaneous
C) Posterior radial collateral
D) Radial recurrent
E) Superior ulnar collateral
The correct response is Option C.
The correct answer is the posterior radial collateral artery, which is a branch of the profundus brachial artery. The profundus brachial artery arises from the brachial artery and accompanies the radial nerve. The posterior radial collateral artery passes posterior to the lateral intramuscular septum between the deltoid tubercle and epicondyle. The flap can be harvested from the same extremity, offering pliable tissue for soft-tissue coverage. The lateral arm flap also may be taken with muscle, bone, or cutaneous nerves for composite tissue reconstruction.
The anterior interosseous artery supplies the posterior interosseous artery flap (via its connection to the posterior interosseous artery through the distal interosseous membrane) located on the dorsum of the forearm. This flap may be reversed to cover small to moderate defects on the dorsum of the hand.
The superior ulnar collateral artery arises from the brachial artery in the upper arm. This artery is the blood supply of the medial arm flap. The medial arm flap offers the advantage of a well-hidden donor site; however, flap dissection may be extremely tedious and the flap may have significant subcutaneous fat.
The inferior cubital cutaneous artery may be used as a source of a fascial cutaneous flap in the forearm.
The radial recurrent artery arises from the radial artery below the elbow. This artery anastomoses with the radial collateral artery and can be used as a reversed pedicle flap of the lateral arm skin. This flap may reach to the level of the mid-forearm but cannot reach the hand.
A 45-year-old man is evaluated because of a traumatic plantar heel wound following a calcaneal fracture of the left foot. A pedicled fasciocutaneous flap from the plantar instep is designed for reconstruction. Which of the following best describes the anatomic location of the arterial pedicle of this flap?
A) Between the abductor hallucis and flexor digitorum brevis
B) Between the flexor digitorum brevis and abductor digiti minimi
C) Between the flexor hallucis brevis and adductor hallucis
D) Between the flexor hallucis longus and quadratus plantae
E) Between the tendons of the extensor hallucis longus and extensor digitorum longus
The correct response is Option A.
Reconstruction of the weightbearing plantar surface ideally requires skin that is sensate and glabrous. When possible, replacing like-with-like tissue is preferred. The donor site for the medial plantar artery flap is located on the non-weightbearing plantar surface and provides tissue that is structurally similar to the plantar area of the hind foot including fibro-fatty subcutaneous tissue and plantar fascia.
The medial plantar artery is a terminal branch of the posterior tibial artery, and lies between the abductor hallucis and flexor digitorum brevis. Fibers of the medial plantar nerve can be harvested with the flap to provide sensation. The flap can also be raised as a distally-based flap from retrograde flow through the lateral plantar artery for forefoot wounds, or as a free flap. This flap has been shown to provide reliable reconstruction of the plantar surfaces.
The lateral plantar artery runs between the flexor digitorum brevis and abductor digiti minimi. The dorsalis pedis artery runs between the extensor hallucis longus and extensor digitorum longus tendons. The remaining muscle intervals do not contain any major arterial branches used in flap reconstruction.
Which of the following arteries most likely supplies a vascularized bone free flap from the medial condyle of the femur?
A) Descending genicular
B) Medial femoral circumflex
C) Posterior radial collateral
D) Posterior tibial
E) Sural artery
The correct response is Option A.
There has been recent increased interest in the use of the medial condyle of the femur as a source of vascularized bone. The blood supply appears to be robust and predictable. In one study, the descending genicular artery was present in 89%, and the superior medial genicular artery was present in 100% of specimens with average distances proximal to the articular surface of 13.7 cm and 5.2 cm, respectively.
The posterior radial collateral artery is the pedicle for the lateral arm flap. The sural artery perfuses the posterior skin of the calf. The medial femoral circumflex artery lies in the upper thigh and helps supply blood to the neck of the femur. The posterior tibial artery carries blood to the plantar surface of the foot from the posterior artery.
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 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 42-year-old man undergoes resection of a dermatofibrosarcoma protuberans of the lower abdomen. A 15 × 9-cm skin and subcutaneous defect results and is closed with a pedicled anterolateral thigh flap. The most common dominant blood supply to this flap is which of the following arteries?
A) Ascending branch of the lateral femoral circumflex
B) Ascending branch of the medial femoral circumflex
C) Descending branch of the lateral femoral circumflex
D) Descending branch of the medial femoral circumflex
E) Transverse branch of the lateral femoral circumflex
The correct response is Option C.
The anterolateral thigh flap (ATL) is most frequently used as a free flap. However, it is an extremely reliable and versatile pedicled flap which can be used to reconstruct a variety of lower abdominal, perineal, and pelvic defects. Proximally based ATL flaps are based on flow from the descending branch of the lateral femoral circumflex artery. The descending branch runs between the vastus lateralis laterally and the rectus femoris medially. The perforators from this vessel run through the vastus lateralis to supply the overlying skin. Perforators usually penetrate the anterior aspect of the vastus lateralis. In less than 15% of cases, the perforators run in the septum between the vastus lateralis and the rectus femoris, and in this case, no intramuscular dissection is required.
The medial femoral circumflex is the other main branch of the profunda femoris artery. It divides into the ascending superficial, deep, and acetabular branches and supplies the adductor brevis and magnus as well as the femoral neck. The lateral femoral circumflex divides into ascending, descending, and transverse branches. The ascending or transverse branch and its perforators supplies the tensor fascia lata muscle, and the descending branch supplies the rectus femoris. Its perforators supply the vastus lateralis and its overlying skin.
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.
A 43-year-old electrician sustains a high-voltage electrical injury and undergoes multiple debridement procedures of the right upper extremity. The hand, ulnar aspect of the forearm, and medial upper arm are spared. Two weeks following the injury, a final debridement is performed leaving a 6-cm segment of the brachial artery and median nerve exposed in the proximal forearm. Which of the following is the most appropriate method for wound coverage?
A) Above-elbow amputation
B) Dermal substitute followed by skin graft
C) Free tissue transfer
D) Local tissue flap
E) Split-thickness skin graft
The correct response is Option D.
The most appropriate method for wound coverage is a local tissue flap, which could come from the intact medial upper arm and/or ulnar aspect of the forearm. A split-thickness skin graft is not appropriate coverage for vital structures. The time it takes for a dermal substitute to vascularize and form the basis of subsequent grafting is too long to leave such vital structures exposed. Free tissue transfer is an option; however, this patient is 2 weeks out from injury and the associated hypercoagulable state is a relative contraindication if local tissues are available. Above-elbow amputation is not an appropriate option as the hand is spared and there are viable coverage options for this young manual laborer.
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 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.
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 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 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 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 25-year-old man is brought to the emergency department after he sustained a mutilating injury to the right hand and wrist that requires soft-tissue reconstruction. Examination shows exposed tendon and bone over the dorsum of the right hand and wrist. The zone of injury extends to the level of the elbow. Allen test is abnormal. Which of the following is the most appropriate method of reconstruction?
A) Coverage with a groin flap
B) Coverage with a reverse radial forearm flap
C) Full-thickness skin grafting
D) Negative pressure wound therapy
E) Split-thickness skin grafting
The correct response is Option A.
The patient described has a mutilating injury to the dorsum of the hand and wrist with exposed extensor tendons and metacarpals, which would not be an appropriate bed for a skin graft. Skin grafts survive initially by plasmatic imbibition and then by inosculation from the wound bed. Wounds with extensive exposure of tendons do not provide the potential for in-growth of vascularized tissue to maintain a skin graft. The radial forearm flap cannot be used in this patient because the palmar arch has been injured and the patient does not have communication between the radial and ulnar arterial system such that arterial compromise can occur if the radial artery is transected for the flap. Negative pressure wound therapy can be considered temporarily, but will not provide definitive management of this complex wound.
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.
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 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 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.
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 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 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 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 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.
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.
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.
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.
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
