Use of NPWT with and without Soft Port technology in infected foot wounds undergoing partial diabetic foot amputation.

OBJECTIVE: Negative pressure wound therapy (NPWT) has previously been shown to be effective in closing diabetic foot wounds that have undergone amputation over a 16-week period. For patients with plantar foot wounds, NPWT is a key therapy. An alternative NPWT with and without a novel soft, flexible port system needs to be evaluated for its comparable efficacy. Our objective was to show the non-inferiority of an alternative negative pressure system, and in a small subset, a novel foam dressing system.

METHOD: We performed a single centre prospective study of patients with diabetes undergoing open bone resection in the foot for acutely infected wounds. Wounds were treated with NPWT/soft port technology (SPT), for 112 days or until primary closure or the wound was deemed ready for delayed primary closure. Rate of closure and quality of life were analysed. A previously published cohort was used as a control.

RESULTS: Of the 30 patients initially recruited, 29 met eligibility requirements and had NPWT applied a median of 2 days postoperatively. There were seven patients (24%) who had delayed primary closure (mean=58 days) and 52% had sufficient progress to change in treatment (15/29; mean=62 days). Only one patient reached the 112-day mark without sufficient progress to be closed. The primary method of delayed primary closure was split-thickness skin graft. There was a reduction in wound area 56.3% (initial mean area=17.4cm(2) to final mean area=7.6 cm(2); p=0.001) at the end of treatment (mean=58.7 days) reduced to 4.3cm(2) a 67.2% reduction (p=0.004) at the end of study (112 days).

CONCLUSION: The alternative NPWT and the soft port technology was well tolerated and effective in the population in aggregate. There was no inferiority between the two technologies. The aggregate closure or progression to be ready for closure rate of 75% at 69 days compares very favourably with previously published data for NPWT in this population of 56% at 56 days (range: 26-92 days). Both cohorts did significantly better than previously published standard of care closure rates of 39% at 77 days.

DECLARATION OF INTEREST: J.C. Lantis is a paid consultant for Smith & Nephew, Acelity, Macrocure and Manukamed. This trial as supported by an institutional grant to St Luke's and Roosevelt Hospital sponsored by Smith & Nephew. The outcome of the trial had no bearing on the condition of the grant. No investigator holds an equity position in Smith & Nephew. C. Gendics is a paid consultant of Acelity.