- Discussion:
- pedicle flaps can incorporate a variety of tissues, ranging from skin and subQ fat to essentially a complete finger;
- used to provide coverage in areas where tendon (denuded of epitenon), bone (denuded of periosteum), or joints are exposed;
- areas that must support tendon grafting or transfers are best covered w/ pedicle flap;
- periosteal surfaces can be skin grafted, but flap coverage provides more durable surface that is less prone to traumatic breakdown;
- pedicle flaps can be used to provide sensation or specialized tissues
- blood supply to pedicle flaps is thru intact base, stalk, or pedicle;
- donor site is closed primarily or is skin grafted;
- local flaps are obtained within the area of the defect and mobilized to fill the defect;
- regional flaps are further removed from the defect but raised on the same extremity;
- most regional and all distant pedicle flaps coverage requires at least two stages;
- in the first stage the flap is inset at the recipient site;
- more complete the inset at primary stage, more extensive vascular ingrowth into the flap;
- vascular supply of either local or distant pedicle flap can be enhanced by the staged division of a portion of its vascular supply
(delay maneuver), thereby encouraging a more efficienct circulation;
- this permits its use of a greater length to width ratio than would otherwise be possible;
- after flap has established sufficient vascular connections w/ recipient site, the second stage, pedicle transection and inset completion, is performed;
- Axial Pedicle Flaps:
- classified as either peninsular or island
- peninsular flaps maintain tissue continuity across the length of to the donor area;
- island flaps consist of an island of skin, muscle, fascia, or subQ tissue maintained on a debulked or skeletonized pedicle;
- flaps are often designed of greater dimension than initially estimated to avoid tension, since undue tension will initially impair venous return;
- tension associated with a single suture can produce a white line across a flap, resulting in distal necrosis;
- thick flaps are less pliable and compensations for their inelasticity must be made;
- pallor reflects inadequate arterial supply, while cyanosis indicates venous congestion;
- mottling, cyanosis, and and edema herald impending necrosis, and violet discoloration signals established tissue necrosis;
- hematoma or seroma between the flap and recipient bed will impair healing and predispose to infection and flap necrosis;
- hematoma can also reduce vascular flow thru direct pressure;
- Innervated Pedicle Flaps:
- innervated flaps are used primarily to provide coverage of the working (opposable) surfaces of the hand;
- this includes the ulnovolar surfaces of the thumb pad and the radio-volar surfaces of the finger pads;
- these flaps can be developed from local or regional tissues
- References:
Wound tension and blood flow in skin flaps.
Complications of 100 Consecutive Local Fasciocutaneous Flaps.
An Anatomic Review of the Delay Phenomenon: II. Clinical Applications.
Classification of the vascular anatomy of muscles: experimental and clinical correlation.
Muscle flap transposition with function preservation: technical and clinical considerations.
When does a random flap die?
Tissue oxygen measurements in delayed skin flaps: a reconsideration of the mechanisms of the delay phenomenon.
Enhanced capillary blood flow in rapidly expanded random pattern flaps.
Augmentation of blood flow in delayed random skin flaps in the pig: effect of length of delay period and angiogenesis.