A Cochrane review included 17 studies with a total of 1 034 subjects. In 12 studies participants also received compression bandaging. Eleven trials compared a graft with standard care in which no graft was used. Two of these trials (n=102) compared a dressing with an autograft; 3 trials (n=80) compared frozen allografts with dressings, and 2 trials (n=45) compared fresh allografts with dressings. Two trials (n=345) compared tissue-engineered skin (bilayer artificial skin) with a dressing. In two trials (n=97) a single-layer dermal replacement was compared with standard care. Six trials compared alternative skin grafting techniques. The first trial (n=92) compared autografts with frozen allograft, a second (n=51) compared a pinch graft (autograft) with porcine dermis (xenograft), the third (n=110) compared growth-arrested human keratinocytes and fibroblasts with placebo, the fourth (n=10) compared an autograft delivered on porcine pads with an autograft delivered on porcine gelatin microbeads, the fifth trial (n=92) compared a meshed graft with a cultured keratinocyte autograft, and the sixth trial (n=50) compared a frozen keratinocyte allograft with a lyophilised (freeze-dried) keratinocyte allografts.
Significantly more ulcers healed when treated with bilayer artificial skin than with dressings (RR 1.51, 95% CI 1.22 to 1.88; 2 studies, n=345). There was insufficient evidence from the other trials to determine whether other types of skin grafting increased the healing of venous ulcers.
Comment: The quality of evidence is downgraded by study limitations (unclear allocation concealment and inadequate intention-to-treat adherence).