Keys To Optimizing Split-Thickness Skin Grafts

Split-thickness skin grafting is an underutilized modality that is easy to perform, has minimal cost and offers exceptional efficacy. A well-performed STSG is low risk and has a healing time of three to four weeks in both low and high-risk patients. Many clinicians are timid about this modality while others lack the proper scope of practice in their state. Nonetheless, skin grafting is a viable option of tremendous value. 

When I consider a patient for a skin graft, I evaluate the likelihood if the patient can heal his or her wound faster with or without a STSG. If the wound is healing too slowly, I introduce the STSG as part of the plan. When the wound is progressively improving but the residual wound remains too large and the risk of infection is high, one should consider a STSG. 

Preoperatively, there are several important considerations. Mechanical or enzymatic wound bed preparation is a valuable means toward facilitating wound closure. A prerequisite for any STSG is a healthy granular foundation. In the outpatient setting, one often facilitates this by using a dermal curette. There should, however, be a low threshold for surgical debridement. 

Intraoperatively, tissue cultures can help you understand the associated flora and direct tailored antibiotics as necessary. It is wise to ensure a healthy, vascular, non-infected wound bed prior to committing to a STSG. Thus, I educate and obtain the consent of my patients for a debridement and “possible” skin graft. The wound may require several surgical debridements prior to finally committing to a STSG. I prefer a hydroscalpel for surgical debridement, particularly for wound bed preparation on the day of skin grafting. 

Antibiotic coverage for STSGs can quickly become tricky. There are three important principles to keep in mind. All venous stasis ulcerations require antibiotics to treat against Pseudomonas prior to skin grafting. All wounds associated with underlying osteomyelitis require extended antibiotics prior to grafting, even if one has resected osteomyelitis. Finally, in addition to metabolic optimization for all patients with suboptimal glycemic control, these patients should also receive empiric coverage for gram positive organisms perioperatively. Timing of antibiotic therapy is on a case by case basis and extends across the perioperative course. 

There are a few other intraoperative considerations. First, it is best to harvest from the ipsilateral limb, most commonly the anterolateral thigh, which should be devoid of scar, rash or any other dermatopathology. Tumescent local anesthetic infiltration should include, at minimum, the surface area of the dermatome. A common mistake is to only infiltrate under the area measured for the STSG/wound area. Keep in mind that the dermatome needs to glide over the skin evenly for a more even harvest. Mineral oil can also help with even gliding during the harvest. One should base the width of the dermatome on the width of the planned graft while the length should always be longer, traversing the dermatome over the skin until one has obtaining the measured length of the graft. 

The more contentious intraoperative decision is what thickness of STSG to harvest. In general, you will find an overabundance of literature relating to skin graft thickness. Interestingly, thickness seems to matter significantly with respect to take and overall outcomes. If the skin from the thigh is of good quality, it is reasonable to obtain a graft between 0.10 and 0.14 inches. One should mesh the harvested skin based on the size of the wound needing coverage or pie crust/ fenestrate the graft. The surgeon should affix the skin graft via sutures. The type of suture and technique is of little consequence as long as it stays put. I prefer a continuous running 5-0 Prolene. 

One must bolster all STSGs or apply negative pressure wound therapy (NPWT). These modalities prevent shear forces and hematoma/seroma formation, both of which are devastating to graft take. I prefer a three- to four-layer compression dressing as my bolster. Otherwise, I use NPWT. There is much debate about what pressure a STSG can tolerate. Whether one is using a bolster or NPWT, STSGs are resilient to pressure as long as the patient has adequate perfusion to the wound angiosome. The provider may reduce NPWT pressure as necessary. 

Postoperative results will vary. While the graft for some patients will look great at week one, for other patients, the graft may appear ischemic or macerated with wound bed fibrosis. Patience is the most important part of the post-skin graft evaluation. Most grafts will look worse before they look better. Also, even if a portion of the graft fails, the areas that completely take will continue to epithelialize the wound. 

All in all, nothing can substitute for a patient’s own skin. Autologous skin grafting is worth exploring. Biologic allografts can help build an adequate wound bed. Moreover, tissue allografts and other specialized wound products may help post-STSG patients with suboptimal take. Although there are patients for whom a STSG may not be the ideal choice, STSG can indeed facilitate positive outcomes. n 

Dr. Elmarsafi is a fellowship-trained attending physician who is affiliated with the Department of Plastic Surgery at Georgetown University Hospital and Washington Hospital Center in Washington, D.C.