Diabetes mellitus when combined with peripheral neuropathy, foot deformity and ischemia can increase an individual’s risk of developing diabetic foot ulcerations1. Diabetic foot ulcers can be very challenging to treat and increases the burden on the health care system. Conservative treatment of diabetic foot wounds includes regular wound debridements, offloading, negative pressure wound therapy (NPWT) and myriad of topical wound dressing [2, 3]. In the last decade many biological dressings have been described and utilized. Split-thickness skin graft (STSGs) have not been traditionally used in chronic diabetic wounds and wounds on plantar, weight bearing areas. However it remains our first line procedure to heal diabetic foot ulcers as it has been found to successfully and rapidly heal complex diabetic foot wounds [4, 5].
The objective is to achieve wound closure involve a “vertical” and “horizontal” strategy. Our vertical strategy involves utilizing NPWT to reduce the depth of a wound initially. A local or free flap may also be used for this purpose in some circumstances. Our horizontal strategy involves methods to achieve epithelialization/coverage. This may be achieved with surgical debridement and good quality offloading alone in smaller wounds (total contact casting), or assisted via “advanced” wound therapies with or without skin grafting.
To prepare the wound, we perform surgical debridement utilizing a combination of scalpel, curette and hydrodebridement tools to create a wound base capable of producing and maintaining granulation tissue . We follow this with application of NPWT as described above until an appropriate recipient bed is present (often 2-4 weeks).
We generally harvest skin graft from the ipsilateral thigh of 0.0012-0.0018 inches in thickness [4, 5, 6]. We choose a slightly thicker-than-normal graft because of the more significant demands for durability placed on the foot. Alternatively skin graft can be harvested from the leg as well. We use staples or absorbable sutures to secure the graft to the wound base. We apply a NPWT dressing for one week and a splint when needed to reduce motion in foot and ankle for the initial dressing.
Diabetic foot ulcers that are free of active infection with granular wound base.
STSG should not be used on wounds that are fibrotic, have an active infection and are deep in nature. It is also paramount to evaluate patient for ischemia and do a vascular consult if needed to resolve any ischemia prior to moving forward with this procedure [4, 5].
This procedure is done with the patient under general anesthesia. We use local anesthetic with epinephrine to the harvesting site.
We apply NPWT dressing in the operating room to the recipient site. NPWT has been utilized successfully as a bolster dressing for STSGs and has shown to help incorporate STSGs faster, decrease seroma and hematoma formation and help conform the graft to difficult uneven wounds [6, 7, 8]. We keep NPWT dressing at 75mmHg to 125mmHg as indicated for 5-7 days. We remove the NPWT dressing in clinic making sure the skin graft is kept well adhered to the wound base as the dressing is removed. We examine the skin graft and wound site for any signs of infection. We also examine any offloading devices that are being used such as the splint for its integrity as it may need to be replaced. If skin graft is taking well then we apply a non adherent to the skin graft and wet to dry gauze dressing as our next dressing. Patient is instructed to change this dressing every other day for the first two weeks until the graft shows signs of incorporation. If staples were used, we remove the staples in three to four weeks.
We apply a non adherent dressing with 3% bismuth tribromophenate covered with an occlusive dressing. We have also utilized platelet rich plasma dressing as it has been shown to decrease pain at the harvest site . We keep the harvest site dressing for two weeks. This will allow the harvest site to heal without any interruption. We apply a non adherent occlusive dressing until the harvest site forms an eschar then we do not apply any dressing.
STSGs are at a risk for infection especially in the first week given graft may not have fully incorporated and vascularized. Pseudomonas is an opportunistic bacteria and have been known to infect skin grafts often. We sometimes use acetic acid wet to dry dressing if patient has had previous pseudomonas infection or shows signs of active pseudomonas colonization . Appropriate use of antibiotics should be considered if there are any signs of infection at the donor or recipient site.
STSGs may fail in the near-term due to seroma or hematoma formation, in the near to mid-term from infection and in the medium to long-term from repetitive moderate or constant low-grade normal/shear stress. Therefore, in the near term, it is important to achieve appropriate hemostasis prior to application of the graft to the wound base. If there is a seroma or hematoma formation it must be evacuated to keep the skin graft from lifting off the wound base and getting infected as seroma can be a nidus for infection. Negative Pressure Wound Therapy is frequently helpful in some of this regard. It may serve either as a protective bolster, an avenue for drainage, and a controlled environment to facilitate incorporation.
Furthermore, in lower extremity wounds weight bearing and shearing forces may prevent STSG from healing however proper immobilization with posterior splint or cast will help with this .
Other complications include non healing or delayed healing of harvest site however this is quite rare. It is important to evaluate patient for any factors that would prevent harvest site from healing prior to this procedure.
- Singh N, Armstrong DG, Lipsky BA. Preventing foot ulcers in patients with diabetes. 2005; (2): 217-228.
- Isaac AL, Armstrong DG. Negative pressure wound therapy and other new therapies for diabetic foot ulceration: the current state of play. Med. Clin. North. Am., 2013 Sep; 97 (5): 899-909.
- Armstrong DG, Lavery LA, Nixon BP, Boulton AJM. It’s not what you put on, but what you take off: techniques for debriding and offloading the diabetic foot wound. Clinical Infectious Diseases, 2004; 38: S92-S99.
- Lew EJ, Sauciuc V, Armstrong DG. Pearls and Pitfalls of Ssplit Thickness Skin Grafting the Diabetic Foot Ulceration. Journal of Wound Technology, 2014;26:16-21.
- Rose JF, Giovinco N, Mills JL, Najafi B, Pappalardo J, Armstrong DG. Split-thickness skin grafting the high-risk diabetic foot. Journal of Vascular Surgery, 2014; 59(6):1657–63.
- Giovinco NA, Zubrak MS, Armstrong DG. Technique Pearls For Application of And Maintenance of Split-Thickness Skin Grafts in Foot Wounds. The Podiatry Institute. 2014; 28: 171-174.
- Moisidis E, Health T, Boorer C, Ho K, Deva AK. A prospective, blinded, randomized, controlled clinical trial of topical negative pressure use in skin grafting. Past. Reconstr Surg 2004;114:917-22.
- Issac AL, Rose J, Armstrong DG. Mechanically Powered Negative Pressure Wound Therapy as a Bolster Dressing for Skin Grafting. Past. Reconstr. Surg Glob Open, 2014; 2:e103.
- Miller JD, Rankin TM, Hua NT, Ontiveros T, Giovinco NA, Mills JL, Armstrong DG. Reduction of Pain via Platelet-rich Plasma in Split-Thickness Skin Graft Donor Sites: A series of Matched Pairs. Diabet Foot Ankle. 2015:6;24972.