Full-thickness skin grafting for coverage of dorsal hand defect

Procedure: This video depicts the use of a full-thickness skin graft to cover two defects on the dorsum of the hand in a patient who had undergone numerous prior debridements for necrotizing cellulitis of the hand. Introduction: Defects on the dorsum of the hand are a common result of multiple debridements or Mohs’s surgery of the hand. Closure of dorsal hand defects presents a challenge for plastic surgeons, as contraction of the wound either by primary closure or secondary intention can impair hand flexion. Indications/Contraindications: Full thickness skin grafting of the hand is indicated following any procedure which leaves a >1cm defect. This patient had two defects measuring 15cm2, which required closure either by adjacent tissue flap, or skin graft. For defects of the hand, full thickness skin grafting is preferred to split thickness skin grafting. Materials and Methods: The dorsal hand wounds were debrided sharply with the edge of a metal ruler. A skin graft was taken sharply with a 15-blade scalpel from the axilla, where there was determined to be adequate laxity for primary closure. Results: The graft was vented and sutured in place with a running chromic suture. Negative pressure dressing with silver nitrate was applied at the end of the case. The patient was seen at their postoperative clinic visit and had no complications. Conclusion: This report demonstrates how to perform an full-thickness skin graft for coverage of a dorsal hand defect.

Purpose of technique: Skin grafting is one of the fundamental procedures of plastic surgery, allowing for coverage of defects that are unable to be closed primarily, either due to their size or their location. Full-thickness skin grafts (FTSG) and split-thickness skin grafts (STSG) both allow for coverage of wounds that are not amenable to healing by secondary intention. Proper patient/case selection (indications): FTSG is indicated in defects where primary closure is not feasible, and there is lack adjacent tissue suitable for coverage1. FTSG is the first line therapy for closure of defects on the dorsum of the hand >1cm2 2. This patient had two defects measuring approximately 15cm2 on the dorsum of the hand. FTSG is preferred to STSG in this patient (see below for rationale). Contraindications (absolute and relative): FTSG is absolutely contraindicated at infected recipient sites, and sites with compromised blood supply, including exposed bone or cartilage >1cm2 1,2. It is also contraindicated in patients who do not have a donor site that can be closed primarily (i.e. massive burn patients)1. Additionally, patients who are immunosuppressed or have peripheral vascular disease have a decreased chance of graft survival3. Advantages and disadvantages over alternative techniques: Options for closure of defects >1cm2 include, primary closure, healing by secondary intention, STSG, FTSG, and adjacent tissue flap4. Healing by secondary intention is contraindicated for wounds >1cm2 on the dorsum of the hand, as the resulting scarring and contracture will impair flexion of the hand2. Similarly, the dorsum of the hand does not have enough laxity to accommodate primary closure of wounds this size. Adjacent tissue transfer is a poor option because donor skin on the dorsum of the hand is often poor in quality, and typically contracted, which increases the risk of donor morbidity2. FTSG is preferred to STSG because it has a lower risk of contracture and an improved chance of regaining sensation1,3. Additionally, FTSG permits better skin color matching of the graft with the recipient site, which creates a better cosmetic result. The donor site can be anywhere on the body with enough laxity to permit primary closure, typically the inner thigh or axilla, and there is usually little to no donor site morbidity. Therefore, FTSG is the ideal method of closure for this patient. Complications and risks: The primary complications of skin grafting is graft failure. This can be caused by hematoma, seroma, infection, or poor graft fixation1. All of these obstruct the diffusion of nutrients and oxygen from the tissue below to the graft, and result in graft loss. Grafts can also be complicated by pigment changes from the donor skin to the recipient skin and scarring, which affect the cosmetic result1.

Instrumentation (please include device company and model number, if available): 15-blade scalpel, 1% lidocaine with epinephrine, Adson pickups, 4-0 chromic gut suture Setup: Skin grafting may be performed under local anesthesia with monitored anesthesia care (MAC). Preoperative workup: Modifiable risk factors for complications should be checked prior to surgery. The recipient bed should ideally be proven culture-negative (though this is not always done in practice). Smoking should be stopped at least 2 days prior to and after surgery4, and blood glucose level should be controlled. Anatomy and landmarks with figures as needed. Skin grafts can either be full-thickness skin grafts (FTSG) or split-thickness skin grafts (STSG). FTSGs contain epidermis and the full thickness of the dermis, while STSGs only contain a small part of the dermis. Skin grafts heal initially by diffusion of nutrients from the recipient bed1. This requires both vital tissue in the recipient bed and an uninterrupted path of nutrients from the bed to the graft1. Detailed steps to procedure: The recipient site is identified and marked on the patient. The recipient and donor sites (in this patient, the axilla) are prepped and draped in a sterile fashion. The defects are measured to estimate the size of the graft. An elliptical graft is then marked on the axilla, which overshoots the size needed to cover the graft. Prior to incision, the edges of the proposed donor site are approximated to ensure primary closure. The recipient bed is debrided of granulation tissue with the sharp edge of a metal ruler. Debridement is considered adequate when healthy, bleeding tissue is reached. The incision is made at the donor site with a 15-blade scalpel. The incision should go through dermis, but should avoid penetrating deeper than subcutaneous fat. The corner of the graft is elevated with an Adson pickup, and the graft is dissected away sharply with a scalpel along the dermal-hypodermal plane. The graft is amputated, and the donor site is closed first with a deep-dermal layer of 3-0 Vicryl suture, and then with a 4-0 Monocryl subcuticular layer. The graft is de-fatted along its deep edge, and is approximated to the defect. The grafts are then secured in a “ship-to-shore” fashion (suturing from graft to recipient edge) to the recipient bed. The graft is vented with tissue-cutting scissors, and then a negative pressure dressing is applied using Silverlon dressing to prevent skin maceration and provide bacteriostasis. A soft dressing is applied to the patients hand and the patient is instructed to keep the hand immobilized until his/her clinic follow-up in 4-5 days.

A positive result of this procedure is determined by the degree of graft “take”. This is defined as the percentage of the graft that survives as living skin on the recipient bed. A negative result this procedure is a graft with all or some of the recipient site occupied by necrotic skin4. The graft will heal and contract over the next 18 months if it takes1. FTSGs have a lower rate of contraction than STSGs, due to the increased amount of dermis in the graft, which reduces the rate of secondary contraction5. An unacceptable result would also include functional impairment of the appendage being grafted, which in this case would manifest as contracture impairing flexion of the hand2. Additional complications including infection, bleeding, or damage to structures in the donor site or recipient site are rare.

Critical steps of the procedure: The critical steps of this procedure is the securing of the graft to the donor site with a running “baseball stitch” suture, and the venting of the graft with tissue-cutting scissors. Both of these steps are vital to ensuring an uninterrupted path of nutrients from the recipient bed to the graft above. Failure to properly secure the graft allows shearing forces to move the graft off of the recipient bed, increasing the distance of diffusion of nutrients into the graft. Failure to vent the graft can allow accumulation of hematoma or seroma under the graft which also obstructs the diffusion of nutrients to the graft, and causes graft failure, and need for future surgery. Common modifications: Common modifications of this procedure include site selection for the donor, and bolstering versus negative pressure dressing for securing the graft. Regarding the donor site, any inconspicuous donor site that has the skin laxity necessary for primary closure is appropriate, and patient preference may be used to guide this decision as well. Negative pressure dressing provides an advantage over bolstering because the negative pressure on the wound is believed to increase blood flow to the wound, stimulates granulation, and reduces interstitial edema and bacterial load7. Common pitfalls: The most common pitfall of FTSG is failure to properly secure the graft to the recipient site, allowing shear stress to disrupt the diffusion of nutrients to the graft. Inadequate defatting of the skin graft can also impair diffusion and result in graft failure1. Troubleshooting of the technique(s): By securing the graft to the recipient bed in a “ship-to-shore” fashion, adequate bites can be taken to allow for the graft to be secured without shearing it or shifting it, and limiting tension on the graft site. Defatting of the graft should be performed under loupe magnification with a tenotomy or other tissue-cutting scissor to ensure its adequacy. Limitations of the technique: While FTSG is a very useful technique for closing wounds on the dorsal hand and palm, it should not be used for coverage of defects on the fingertips6. FTSG on the fingertip creates excess bulk on the volar pad. While FTSG is superior to STSG in terms of sensation regained2, a skin-grafted fingertip will have diminished sensation relative to the other digits, which reduces the function of the repaired digit6. Defects of the fingertip that are too large to be closed primarily can be closed with a dorsal-volar V-Y advancement flap. If this still fails to close the defect, loose sutures can be placed to allow 2mm of space between the V and Y flaps. This wound will close by secondary intention6. FTSG is not recommended for large defects, and STSG is more appropriate for these as they can be meshed to cover a greater surface area1. Alternatively, if FTSG is required, a tissue expander may be used preoperatively to increase the size of the donor1. Potential further applications of the technique(s): FTSG can be used to cover small defects on the hand, face, and other extremities for which STSG is otherwise contraindicated5.

There was no funding for this project and the authors have no financial disclosures or conflicts of interest.

We would like to acknowledge the Vanderbilt Digital Slide Collection for access to histologic images for figures.

1. Brown DL, Borschel GM, Levi B. Michigan Manual of Plastic Surgery. 2nd ed. Lippincott Williams And Wilkin; 2014. 2. Gloster HM, Daoud MS, Roenigk RK. The Use of Full-Thickness Skin Grafts for the Repair of Defects on the Dorsal Hand and Digits. Dermatologic Surgery. 1995;21(11):953-959. doi:10.1111/j.1524-4725.1995.tb00532.x. 3. Reddy S, El-Haddawi F, Fancourt M, et al. The incidence and risk factors for lower limb skin graft failure. Dermatol Res Pract. 2014;2014:582080. doi:10.1155/2014/582080 4. Ramsey ML, Patel BC. Full Thickness Skin Grafts. [Updated 2018 Dec 20]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2019 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK532875/?report=classic 5. Jones AP, Janis JE, Barnard AR. Essentials of Plastic Surgery. Boca Raton, FL: CRC Press, Taylor & Francis Group; 2016. 6. Elliot D, Adani R, Woo SH, Tang JB. Repair of soft tissue defects in finger, thumb and forearm: less invasive methods with similar outcomes. Journal of Hand Surgery (European Volume). 2018;43(10):1019-1029. doi:10.1177/1753193418805698. 7. Stanley BJ, Pitt KA, Weder CD, Fritz MC, Hauptman JG, Steficek BA. Effects of negative pressure wound therapy on healing of free full-thickness skin grafts in dogs. Vet Surg. 2013;42(5):511–522. doi:10.1111/j.1532-950X.2013.12005.x