Weekly Changes in Wound Parameters Following Treatment with Either Single-Use or Traditional Negative Pressure Wound Therapy: Results of a Randomized Controlled Trial in Patients with Venous Leg Ulcers and Diabetic Foot Ulcers

Introduction: Early intervention with negative pressure wound therapy (NPWT) in hard-to-heal wounds is associated not only with improved outcomes, but also with lower costs of treatment.

Objective: A multicenter RCT compared traditional NPWT therapy (t-NPWT) with single-use NPWT system (s-NPWT) in subjects with VLU or DFU. Ad hoc analyses were performed in order to determine the weekly percentage change in target ulcer surface area, depth, and volume between baseline and end of treatment period or wound closure. A time/response sensitivity analysis was conducted to determine when the highest percentage of mean variations in wound parameters occurred in three different clusters (weeks 1–4, 5–8, and 9–11).

Results: Out of 164 randomized subjects, 161 competed at least one visit (ITT population; 101 with VLU, 60 with DFU). Of these, 115 completed follow-up without protocol deviations (PP population; 64 with s-NPWT and 51 with t-NPWT). The average weekly reduction in wound surface area was 10.2% in the s-NPWT group and 3.8% in the t-NPWT group in DFU patients, and 11% and 2.8%, respectively, in VLU patients. In DFU, s-NPWT led to the largest reductions in area (63.2%), depth (52.6%), and volume (32.5%) during the first four weeks. By comparison, t-NPWT had its highest variation in area (28.7%) during weeks 1–4, in depth (45.3%) at weeks 9–11, and volume (51.0%) at weeks 5–8. In VLU, s-NPWT led to the largest variations in area (59.5%) and volume (42.4%) during weeks 1–4, and in depth (54.5%) at weeks 5–8. By comparison, t-NPWT had its highest variations in area (31.7%) during weeks 2–5 and in depth (46.0%) and volume (47.4%) during weeks 6–9.

Conclusion: These results indicate that this s-NPWT system delivers most of its beneficial effects during the first four weeks of treatment, when wound dimensions may experience an approximate 60% improvement in surface area.