NPWT in skin transplantation: Promising, but is the jury still out?

When a chronic wound has healed, the patient, the family and the physician may feel very relieved. Especially, ulcers located on the lower leg often take months to years to close. The impact on quality of life is significant: Patients often report pain, sleep disturbances and impaired mobility. They may become frail and deteriorate in their ability to perform daily activities.1 Treatment directed at the underlying cause should be started as soon as possible. Then the chances of rapid closure increase.2 For example, in the case of a venous leg ulcer, endovenous thermal ablation is used in cases of an insufficient saphenous vein. Subsequently, the ulcer may be covered with dressings or with autologous punch or split- skin grafts. It is of special interest to read the systematic review performed by M. Gamel et al. in this Issue.3 The article highlights the possibility of skin grafting for chronic leg ulcers and the use of negative-pressure wound therapy (NPWT). Although pain scores were not systematically evaluated in this review, it is important to note that skin grafts often reduce pain and the use of pain medication.4, 5 When pain is reduced, proper wound care and compression therapy may again be possible. From 1381 articles, 21 publications with 1861 patients were included for the review. The study designs included 12 clinical case reports, 4 case series, two retrospective comparative studies and only three prospective randomized controlled trials. The mean age of the included patients was 66 years, and the mean duration of ulcers with a surface of 165 cm2 was 27 months. It is striking to read that it took more than 2 years to apply skin grafts with NPWT in the included publications. The aetiologies of the chronic ulcers varied, with venous ulcers (54%), pyoderma gangrenosum (19%) and arterial ulcers (9.7%) being the most common causes. The authors report a graft take of ≥90% in 77% of the patients (125/162). Complete wound healing was achieved in 79% of patients (110/140), with a mean healing time of 73 days. The conclusion of this review, stating that NPWT improves graft take, accelerates healing and reduces treatment costs while maintaining good patient tolerance, sounds optimistic. First, the primary concern may be that the quality of the included studies was not rated. The heterogeneity among the studies was high, and the included studies often had small sample sizes. In addition, it is not clear whether the endpoints of the studies aligned, for example when and how (blinded observer?) the graft takes were evaluated. Of note, in the three included RCTs published in 2004, 2006 and 2016, the results did not show a significant difference in healing times between NPWT and conventional dressings after skin grafting. Second, treatment costs were not studied in this review. In addition, exploratory univariate analyses were performed to examine graft take across subgroups. However, these groups were often small, making it difficult to draw conclusions. Lastly, adverse effects related to NPWT were reported in 54% of cases, primarily pain or noise-related discomfort. The question if and when to use NPWT in skin-grafted chronic leg ulcer patients may best be answered by a randomized controlled trial focusing on healing rate, tolerability and costs of skin grafting with NPWT compared to skin grafting with immobilization. Rapid closure of a leg ulcer is essential before it becomes chronic and the patient enters a downward spiral. None declared. Data sharing not applicable to this article as no datasets were generated or analysed during the current study.