8 skin flaps grafts wound healing Flashcards
What is an axial pattern flap?
An area of skin supplied by a direct cutaneous artery and vein.
Includes island axial pattern flap and subdermal plexus flap.
What is an island axial pattern flap?
A flap that’s not connected to the donor site by skin, with the skin incised on all edges, rotating on the direct cutaneous artery and vein.
What is a subdermal plexus flap?
Flaps elevated without inclusion of a direct cutaneous artery and vein.
List ways to maximize survival of axial pattern flaps (12).
- Pre-stretching prior to surgery
- Patient preparation (preoperative vs. perioperative antibiotics)
- Culture recipient site after debriding
- Use ultrasound to check artery location
- Measure flap size accurately
- Care with patient positioning
- Prep recipient bed cleanly
- Avoid excessive twisting (not more than 180 degrees)
- Use peripheral tacking sutures
- Close with simple interrupted pattern
- Consider a drain for larger flaps
- Gentle tissue handling
What are postoperative measures to reduce tension, swelling, and inflammation? (6)
- NSAIDs
- Cool packs for first 36-72 hours
- Warm packs for 3-5 days
- Bandage (not too tight)
- Use active drain
- E collar or other protective measures
Name four axial pattern flaps and their clinical scenarios.
- Angularis Oris – facial, palatal, nasal defects
- Superficial Temporal – maxillofacial, eyelid
- Caudal auricular – for large eyelid tumors
- Thoracodorsal – thoracic, shoulder, forelimb defects
What are the 5 stages of acceptance of full thickness free skin grafts?
- Adherence
- Plasmatic imbibition
- Inosculation
- Vascular ingrowth
- Remodelling
What are factors that influence the take of skin grafts? (7)
- the health of the recipient wound bed (vascularity)
- infection at the graft or donor site
- presence of hematoma or seroma
- patient’s overall health (cushings, diabetes)
- wound bed preparation
- surgical technique/gentle tissue handling/suture patterns used
- The type of graft used (axial pattern vs. subdermal plexus)
essentially, any factor that disrupts blood supply to the graft or causes excessive movement or stress on the newly placed skin can lead to graft failure.
Three techniques to eliminate dead space includes _______. (3)
- Adequate subcutaneous sutures
- Tacking sutures
- Negative pressure/active drains
What is the delay phenomenon in relation to axial pattern flaps?
It increases flap survival through staged procedures that restrict blood supply gradually, allowing for better revascularization.
What anatomical features allow for axial pattern flaps in canine and feline skin?
- Direct cutaneous vessels run parallel to skin in dogs and cats
- Greater density of collateral subcutaneous vessels in dogs
- Thinner dog skin compared to human skin
What are four patient factors that affect cutaneous wound healing?
- Species differences (cats vs. dogs)
- Breed (tight skin prone to complications)
- Body condition (increased SC fat challenging)
- Age (geriatric patients have less perfusion)
What are 5 intrinsic local wound factors affecting wound healing? (5)
- Blood supply
- Granulation tissue health
- Bacterial load (contaminated wounds require different management)
- Structural damage (debride devitalized tissue)
- Periwound status (oedema and inflammation)
What is the expected time frame for the adherence phase of free skin grafts?
1st phase:: First 8 hours
2nd phase: 72hrs
What are the phases of integration for free skin grafts? (5)
- Adherence
- Plasmatic imbibition
- Inosculation
- Vascular ingrowth
- Reinnervation
True or False: Dogs have a greater density of collateral subcutaneous vessels compared to cats.
True
What is the significance of using Halsted’s principles during grafting?
They emphasize gentle tissue handling and infection control to improve graft survival.
What happens during plasmatic imbibition phase?
Graft blood vessels vasospasm, expelling blood, then dilate to receive serum-like fluid and cells.
The skin graft passively absorbs oxygen and nutrients from the wound bed via capillary action. During this phase, the skin graft is ischemic and survives on diffusion alone until reestablishing graft vasculature. The graft is pale/white during this time. Split-thickness skin grafts can tolerate up to 4 days of ischemia.
What are dog ears?
Triangular skin protrusions that can affect local structures like the eye but are mostly cosmetically displeasing.
If less than 8mm, they will regress themselves; larger ones should be resected
What is the effect of step defects on healing?
Epithelialisation is delayed.
What are tension relieving suture patterns? (4)
- Strong subcutaneous sutures
- Stent or bolster sutures
- Walking sutures
- Horizontal mattress sutures
- Vertical mattress sutures
What is the purpose of walking sutures?
To create staggered rows of interrupted intradermal sutures that are secured to underlying fascia with directional tension towards closure.
True or False: Horizontal mattress sutures may compromise blood supply to the wound edge.
True.
What is the effect of vertical mattress sutures on blood supply? (2)
Vertical mattresses do not compromise blood supply but can create eversion.
What are the types of skin stretching techniques? (5)
- Pretensioning sutures
- Posttensioning sutures
- Presuturing
- Intraoperative skin stretching
- Chronic skin expansion
What is a VY plasty?
A flap technique that uses a triangular cut to advance tissue and create a Y incision
What is the purpose of Z plasty?
To change the direction of tension and make more skin available.
Can increase length of scar by 50-75%
Fill in the blank: The skin has ______ basic layers.
[two] (epidermis and dermis).
Hypodermis includes SC and adipose/connective tissue
What are the vascular supply divisions in the skin? (3)
- Subpapillary plexus (superficial)
- Cutaneous plexus (middle)
- Subcutaneous plexus (deep/subdermal)
How strong is a surgical wound after 14 days?
5-10% as strong as normal skin.
What is the wound healing difference between cats and dogs?
Cats have lower cutaneous perfusion and wound breaking strength than dogs at 1 week post-op, with healing more by contraction.
List factors that influence wound healing.
- Tension
- Pressure
- Motion
- Self mutilation
- Patient health (uremia, glucocorticoid excess, etc.)
- Infection
How does malnutrition affect wound healing? (4)
- Delayed neovascularisation
- Decreased collagen synthesis
- Prolonged inflammation,
- Decreased immune function.
What is the typical healing strength of skin at 3-4 weeks post-surgery?
25% as strong as normal skin.
What is the role of tension lines in wound closure?
Wounds should generally be made parallel to tension lines to reduce tension during healing.
Taking care of an active drain: (2) to avoid/control infection
- Cover drain exit sites with sterile dressing
- Consider culturing drain fluid when removed
Tension reducing suture patterns (7)
- SC sutures
- bolster/stent sutures
- Walking sutures
- Far, near, near, Far
- Far, far, near near
- horizontal mattress
- vertical mattress
What type of defects does Angularis Oris address?
Facial, palatal, nasal defects
Angularis Oris is involved in reconstructive procedures for facial and palatial areas.
What is the application of the Caudal auricular axial pattern flap?
For dorsal/lateral large eyelid tumours or tumours adjacent to that area
This flap can also be used for reconstructions in the neck, fascial, dorsal head, and ear.
Which anatomical areas does the Thoracodorsal flap cover?
Thoracic, shoulder, forelimb, axillary defects
What defects are associated with the Superficial brachial flap?
Antebrachial, elbow defects
This flap is specifically designed for the forelimb area.
What areas does the Dorsal deep circumflex iliac flap target?
Flank same side, lateral lumbar, pelvic lateromedial thigh, greater trochanter
The Ventral deep circumflex iliac flap is used for which defects?
Lateral abdominal wall, pelvic, sacral defects
This flap is important for reconstructive procedures in the lower abdominal area.
What defects does the Cranial superficial epigastric flap address?
Sternal defects
What types of defects can the Caudal superficial epigastric flap repair?
Inguinal, preputial, perineal, stifle defects
What is the focus area of the Lateral Caudal flap?
Lateral perineal, caudodorsal pelvic defects
The Lateral Genicular axial pattern flap is used for repairing defects in which specific areas?
Medial or lateral aspects of crus (between stifle and tibiotarsal joint)
Fill in the blank: The Superficial Temporal flap is used for _______.
maxillofacial, eyelid area
This flap is crucial for addressing defects in the facial and eyelid areas.
How many branches are associated with the Cervical Cutaneous branch Omocervical?
2
How many branches does the Dorsal deep circumflex iliac flap have?
6
This number indicates its complexity and range.
True or False: The Caudal superficial epigastric flap is primarily used for upper body defects.
False
It is used for lower body defects.
3 advantages of axial pattern flaps over other types of wound closure
- more robust blood supply; flaps can be 2 x size of subdermal plexus
- More reliable survival
- Can be placed over bone, doesnt need granulation tissue/2 stages
Reasons Axial pattern flaps can necrose
- twisting around more than 180 degrees
- excessive undermining
- previous tissue trauma
- damage to primary axial artery and vein during harvesting
- excessive wound tension
- hematoma/seroma formation
- skin flap too long
Whats another name for Delay Phenomenon
Ischemic preconditioning
how long do you leave pre incised skin flap prior to grafting if using preconditioning ischemic technique
3 weeks.
how does uremia affect wound healing (3)
- causes chronic inflammation
- inhibits fibroblasts activity
- reduces collagen production
how strong is wound 14 days after surgery
5-10% as strong as normal skin
what factors affect healing of wounds
tension
pressure
motion
self mutilation
patient health
infection
Time frame Adherance
1-3 days (2 phases)
Time frame plasma imbibition (skin grafting)
1-3 days, peaks at 48-72hrs
what is Inosculation and Time frame (skin grafting)
The graft’s cut vessels connect with the recipient’s capillary beds.
This process usually happens about 48 hours after the graft is placed.
The graft turns pink when inosculation occurs.
1-3 days, reduced perfusion by 5-6days.
what happens during 4th phase skin grafting, name, timing
Vascular ingrowth: vessels grow from the recipient bed into the skin graft, and may grow into the dermis of graft ,
begins within 48hrs, peak vascular growth 5-7days,
Describe deep ventral circumflex iliac axial pattern flap
base of flap is ventral extent cranial aspect wing ilium.
Caudal incision begins that level, midway between wing of ilium and greater trochanter, and extends ventrally.
Distance between caudal incision and cranial edge wing ilium measured;
cranial incision parallel to caudal incision/cranial border femoral shaft and equidistant to iliac wing.
Can extend ventrally to the level of proximal patella.
Flaps elevated beneath the cutaneous trunci muscle.
type of comorbidities that reduce chance of skin flap healing (6)
Infection
anemia
anorexia
cachexia
Uremia
chronic inflammatory dz
post operative factors that impair skin graft healing
- seroma/hematoma formation (drains/bandage)
- infection (culture + Abs)
- excessive movement (splints/bandages)
- self trauma (E collars, bandages)
how long to bandage a skin graft for
24-48hrs
what are Halsteds principles (7)
- Handle tissues with care and avoid damaging them
- Control bleeding effectively
- Maintain the blood supply to the surgical site
- Maintain strict asepsis, or cleanliness, throughout the procedure
- Avoid excessive tension on tissues
- Position tissues accurately
- Eliminate dead space, or areas where tissue has been removed
