Management of Skin Grafts and Flaps


  • Reconstructive surgery of the upper limb has been advanced by the continual addition and use of new flaps and the increasing use of functional free tissue transfer, with improved microsurgical techniques, postoperative management, and intensive rehabilitation.

  • Soft tissue reconstruction options include primary closure, delayed primary closure, healing by secondary intention, skin grafting, local tissue transfer, free tissue transfer, or any combination of these techniques.

  • An algorithmic approach to reconstruction of the upper extremity for the evaluation and treatment of upper extremity wounds and defects is based on the extent and severity of the wounds, the functional needs of the patient, and the availability of required tissue elements. This algorithmic approach facilitates localized healing and optimizes each individual patient’s functional rehabilitation and overall recovery.

Reconstructive surgery of the upper extremity has developed significantly over the last four decades. Microsurgical techniques, a variety of new flaps, and the increasing use of functional free tissue transfer have greatly enhanced the armamentarium of reconstructive surgical concepts and procedures. At the same time, the continuing sophistication of postoperative wound management has created an optimal environment for wound healing, rehabilitation, and overall recovery. Reconstructive surgery has evolved from the practice of simply providing soft tissue coverage for traumatic defects, to a complex algorithmic process of wound management involving thorough clinical assessment, evaluation of individual functional and social needs of the patient, creation and implementation of a surgical plan, and meticulous postoperative management. The algorithmic approach offers a reconstructive ladder for the evaluation and treatment of wounds, ranging from acute traumatic injuries to various chronic conditions, including osteomyelitis, nonhealing wounds, and defects following tumor resection. This ladder directs the reconstructive surgeon to the indicated reconstructive surgical approach, based on the extent and severity of the wound, the functional needs of the patient, and the availability of required tissue elements. The initial goal of the reconstructive surgeon is the reconstitution of the soft tissue envelope, providing a well-vascularized, healthy environment to facilitate localized healing. With successful recovery and healing, the reconstructive surgeon can attain the ultimate goal of optimizing rehabilitation based on individual needs, thus maximizing functional restoration, providing patients with the opportunity for rapid social reintegration and the overall improvement of their quality, productive recovery. This chapter discusses an algorithmic approach to reconstruction of the hand and upper extremity, providing examples of excellent reconstructive options for complex surgical problems, ranging from skin grafts, to local tissue flaps, to advanced free tissue transfer. Management strategies for facilitating localized healing and optimizing functional rehabilitation and recovery are outlined.

Patient Assessment

The first step in developing a reconstructive strategy is the assessment of the patient. The surgeon must recognize the clinical reconstructive needs of the patient, based on the severity of a traumatic injury, the extent and complexity of a chronic wound, or a malignant tumor requiring resection. Important considerations include age, significant medical conditions, preinjury functional status, occupation, dominance of the extremity involved, psychosocial considerations, and individual patient motivation and compliance. In patients with acute traumatic injuries of the upper extremity, a thorough clinical evaluation is necessary to first rule out the presence of other significant life-threatening conditions. Once a patient’s overall condition is established hemodynamically, the clinician may proceed to further assess the extremities. Evaluation of the hand and upper extremity involves a systematic approach to the extremity as a functional organ. Complete examination includes gross visual inspection, evaluation of limb perfusion, assessment of passive and active motion, and a review of neurologic function. Imaging studies, such as radiographs, ultrasonography, CT, MRI, or angiography are incorporated as indicated, to further establish the extent of soft tissue, bone, and vascular involvement. Once the clinical needs of the patient have been clearly established, an algorithmic surgical management strategy can then be created to optimize the reconstruction, postoperative management, and the overall functional rehabilitation of the patient, based on those individual needs.

Management Strategy

A reconstructive management strategy is created based on the evaluation of an injury or wound and the patient’s individual needs. The complexity of the surgical reconstruction is directed by the severity and extent of the wound, the viability of the remaining tissues, and the exposure of underlying vital structures. The first step in surgical wound management is exploration, irrigation, and meticulous debridement. Adequate débridement of all nonviable tissues is required to establish a healthy environment for healing and to decrease the risk of potential infection. Underlying injuries to vital structures must be identified and repaired. Neurovascular injuries need to be repaired either primarily or with the use of conduits if indicated. Fractures must be identified, irrigated, and débrided, and then be stabilized with internal or external fixation. Tendon injuries should be repaired primarily, if possible, or prepared for more extensive future reconstruction as a staged procedure. Following repair of these underlying vital structures, soft tissue coverage becomes the primary consideration. Soft tissue reconstruction options include primary closure, delayed primary closure, healing by secondary intention, skin grafting, local tissue transfer, free tissue transfer, or any combination of these techniques.

Primary Wound Closure

Primary wound closure simply involves reapproximating the wound edges. This is accomplished with the use of sutures, staples, tapes, or skin glue, as a single or multilayered repair. Delayed primary closure suggests a delay in the repair, such as waiting to allow associated edema to resolve enough to facilitate direct skin closing or to allow future reassessment of the soft tissue viability before closure considerations.

Healing by Secondary Intention

Healing by secondary intention refers to leaving a wound open and allowing it to heal spontaneously through contraction and epithelialization. In the hand and upper extremity, healing by secondary intention can be successfully applied to small wounds (with acceptable results) such as fingertip injuries involving less than a 1-cm defect, without exposed underlying bone. Healing of larger hand and upper extremity wounds by secondary intention, however, can result in significant scar formation and contracture, with subsequent limitations in range of motion (ROM) and function.

Skin Grafts

A skin graft is a harvested segment of epidermis and dermis that has been elevated and separated completely from its blood supply. The first reported transfer of skin was credited to Reverdin in 1870, but skin grafting did not become common until the invention of the dermatome by Padget during World War II. The dermatome simplified the method of elevating a skin graft, providing a reliable instrument for consistently harvesting a graft of a desired size and depth. The dermatome remains the primary tool used today for harvesting skin grafts. With the increased use of skin grafts, it was recognized that their early use for wound coverage could retard the extent of wound contracture, thus limiting deformity and functional disability.

Skin grafts can either be full thickness or split thickness. A full-thickness skin graft is a segment that includes the epidermis and entire dermis. A full-thickness graft resembles normal skin more closely, including texture, color, and potential for hair growth. A full-thickness graft demonstrates the greatest amount of primary contracture, but the least amount of secondary wound contracture. That is, after the harvest of a full-thickness skin graft, it quickly contracts and appears much smaller because of the elasticity of the tissues. However, when that full-thickness graft is applied to a wound defect early, it maintains its size and can completely stop the contracture of the wound. Full-thickness skin grafting does have limitations. There is a slightly greater risk of nonadherence of the graft, and donor site availability must be considered before full-thickness skin harvest. A full-thickness skin graft donor site must be amenable to primary closure, or the created donor defect may require an additional split-thickness skin graft for coverage.

A split-thickness skin graft is a sample of partial thickness that consists of the entire epidermis and a portion of the dermis. Partial-thickness skin grafts can be harvested at varying depths and are classified according to the thickness of dermis included: thin split-thickness grafts, intermediate- or medium-thickness grafts, or thick split-thickness skin grafts. Compared with a full-thickness graft, a split-thickness graft demonstrates less primary contracture following harvest, but greater secondary contracture of the grafted wound. A thin split-thickness skin graft produces the least primary contracture because of the decreased elastic tissues, but it produces the greatest secondary wound contracture. A thick split-thickness graft can decrease the rate of wound contracture, but it does not retard it completely as a full-thickness graft can.

A split-thickness skin graft can be either meshed or unmeshed. Split-thickness grafts are typically meshed at ratios of 1:1 to 3:1, with the ratio selected depending on the size of the defect needed to be grafted and the skin available for grafting. Meshing of the harvested skin graft facilitates expansion of the graft for coverage of more extensive wound defects. A split-thickness graft also may be left unmeshed and used to cover a wound as a sheet graft. A sheet graft avoids the meshed-pattern scarring associated with meshed skin grafts, thus resulting in a better cosmetic appearance.

Skin grafts may be secured to the margins of the wound with sutures, staples, tape, or skin glue. At this point, the wound dressing and the postoperative management take precedence. The postoperative wound care can greatly influence the survival of the transferred skin graft. Various potential postoperative complications can lead to the demise of a skin graft. The best method for avoiding graft failure is prevention by meticulous postoperative management. The number one reason for failure of a skin graft is hematoma. A hematoma can form beneath the graft, preventing adherence and promoting graft loss. Prevention includes meticulous perioperative hemostasis and appropriate postoperative dressings. Dressings over a skin graft must provide lubrication to prevent desiccation, appropriate compression to eliminate the potential space between the skin graft and the wound bed, and local immobilization to prevent shearing of the graft. An appropriate dressing promotes imbibition, inosculation, adherence, and success of the skin graft. A lubricating (petrolatum) gauze such as Adaptic, Xeroform, or Xeroflo initially is placed directly over the skin graft, followed by layered moist cotton balls, cotton sheets, or gauze, saturated in a solution such as Bunnell’s, or mineral oil. Bunnell’s solution, consisting of benzalkonium chloride, acetic acid, and glycerin, is the lubricating liquid we prefer. A convex wound may only require a simple dressing under which compression can occur naturally because of the projection of the convex surface of the wound. A concave wound often requires a tie-over dressing, also called a bolster or stent, to compress the skin graft against the surface of the wound defect. This is accomplished with the use of sutures, staples, or a circumferential dressing, to secure the bolster dressing over the skin graft, facilitating graft adherence and healing. Recently the wound vac has been used to stabilize grafts and promote healing.

Graft survival also is enhanced by strict local immobilization. This is achieved by immobilizing the appropriate associated joint(s) with an orthosis, at the level of the digits, wrist, or elbow, to maintain a constant protective position and decrease the risk of shearing of the graft.

Postoperative Follow-up and Management

The dressing over an upper extremity skin graft typically is removed in 4 to 7 days, and the wound is reevaluated. By this time, the skin graft should be adherent to the wound bed, but meticulous wound care is still required to protect the reconstruction. It remains important to maintain a moist/lubricated environment to prevent the persistent risk of desiccation of the skin graft and to facilitate complete healing. This is accomplished with either continued wet-to-wet dressing changes or the application of a lubricating agent such as an antibacterial ointment (e.g., bacitracin). Once complete, epithelialization of the skin graft is recognized, the use of the lubricating ointments and dressings can be discontinued and a simple moisturizing cream started. The continued serial application of a moisturizing cream, such as Eucerin or the equivalent, in combination with gentle massage, can facilitate progressive contoured scar maturation with flattening of the grafted surface and improve the overall cosmetic results. Once adherence of the skin graft is recognized, and as long as there are no significant underlying injuries, rehabilitation of the upper extremity can be initiated and rapidly advanced. Neurovascular, tendon, and bone injuries influence the rehabilitation plan, the timing of which is directed by the individual extent of their involvement.

Management of the Skin Graft Donor Site

We prefer to simply cover the harvested split-thickness skin graft donor site with an OpSite (Smith and Nephew) transparent, adherent dressing, and allow spontaneous reepithelialization of the donor bed. Reepithelialization of the graft donor site typically occurs in approximately 1 week. If fluid collects beneath the dressing, it is simply drained with a needle and the dressing patched with an additional OpSite, or the entire dressing is changed. Following complete reepithelialization of the donor site, dressings are discontinued and the healing bed can be treated for dryness as needed, using a moisturizing lotion such as Eucerin or an equivalent.

Local Tissue Transfer

Earlier in this chapter, we noted that skin grafts are not appropriate for all wounds. For traumatic defects of the upper extremity involving soft tissue loss, with associated exposure of underlying vital structures, such as blood vessels, nerves, tendons devoid of paratenon, bones devoid of periosteum, or wounds with insufficient vascularity to support a skin graft, a more complex reconstructive approach must be used. The surgeon’s initial consideration in this situation is the next step in the algorithmic approach to reconstruction of the upper extremity, that is, use of a local tissue flap. Local tissue transfer refers to the dissection, elevation, and transfer of skin, combined with a varied amount of underlying tissue, potentially including subcutaneous tissue, fascia, muscle, nerve, tendon, or bone. The composition of the tissue harvested and used is determined by the type and extent of tissue loss. During the elevation of a local tissue flap, the local blood supply supporting the flap is preserved. This undivided portion of the flap containing the vascularity required for flap survival, is labeled the pedicle. A local tissue flap can close a local tissue defect, establishing a well-vascularized, healthy environment to potentiate healing of the associated underlying injuries. Local tissue flaps are labeled according to the layers of tissue used, the pattern of the blood supply, and the type of mobilization required.

Skin Flaps

Using a local skin flap for reconstruction of an upper extremity defect refers to rotating adjacent skin and subcutaneous tissue into a wound to supply coverage and closure. A skin flap design is based on the local vascular anatomy of the skin. A random pattern flap is a local skin flap that has no specific arteriovenous system. An axial pattern flap is a single-pedicle skin flap with an anatomically established arteriovenous system along its longitudinal axis. An island flap is an axial pattern flap in which the skin bridge has been separated, leaving only the vascular pedicle intact at the base. Skin flaps are also classified by mobilization techniques, rotational versus advancement. Rotation flaps rotate around a fixed point to reach a wound defect ( Fig. 20-1 ). An advancement flap advances from the donor site to the recipient wound bed in a straight line, without any rotation ( Fig. 20-2 ). Numerous accounts of local flaps are well described in the literature; local flaps are traditionally valuable and versatile options in the reconstruction of many upper extremity defects at all levels: the fingers, hands, forearm, and upper arm.

Figure 20-1

Rotation flap. The flap is designed to rotate around a fixed point to reach a wound defect.

Figure 20-2

Advancement flap. The flap is designed to advance from the donor site to the recipient wound bed in a straight line, without any rotation.

Digital Reconstruction

Our fingers are the tools we use to reach out and engage our environment. Whether at work or at play, our fingers are always in front of us and subsequently are injured often. Fingertip injuries involving a surface area of less than 1 cm, without exposure of bone or vital structures, can simply be allowed to close by secondary intention. Moist dressings can be applied until the wound has reepithelialized. In fingertip injuries involving a surface area defect greater than 1 cm, or digital defects with exposed underlying vital structures, a reconstructive procedure is indicated. The reconstructive goal is to provide wound closure and restore functional sensibility to the finger. As noted before, many well-described local skin flap procedures are illustrated in the reconstructive literature. The selection of a particular surgical procedure is individualized to the patient, based primarily on the size and the location of the wound defect.

V – Y Advancement Flap

The volar V – Y , or lateral V – Y , advancement flaps are skin flaps indicated for small fingertip injuries. These flaps offer a reconstructive dimension of 1 to 1.5 cm. Following appropriate debridement of the injured tissues, the volar V – Y flap is created by making a triangular skin incision(s) just below the defect. The subcutaneous tissue is preserved, and the fibrous septa from the pulp to the periosteum is released. The dissected V -shaped flap is then advanced distally to cover the defect, and subsequently closed in a Y -pattern with surgical sutures ( Fig. 20-3 ). The flap is covered with a nonadherent lubricating gauze and protected with a bulky dressing. Sutures are typically removed in 2 weeks, and early motion is initiated.

Apr 21, 2019 | Posted by in PHYSICAL MEDICINE & REHABILITATION | Comments Off on Management of Skin Grafts and Flaps
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