Negative Pressure Wound Therapy With Instillation and Dwell Time Modifications for Lower Limb Wounds With the Waterfall Technique: A Case Series.

Background: Negative pressure wound therapy with instillation and dwell time (NPWTi-d) is an integrated system that combines conventional NPWT with an irrigation feature. Wound size and location of diabetic foot wounds may make NPWTi-d utilization difficult, commonly resulting in leakages and blockages.

Objective: This study evaluates the effectiveness of a novel waterfall technique, a modification of the usual bridging used during NPWTi-d application, to facilitate the channeling of instillation fluid into diabetic foot wounds with small entry points.

Materials And Methods: A literature review of NPWTi-d use in the treatment of infected diabetic foot wounds and a case series of 9 patients with infected diabetic foot wounds who were admitted to a tertiary health care institution from September 2019 to May 2020 were carried out.

Results: Six patients were male and 3 were female, with a median age of 56 years (range, 45-67 years). All patients underwent a surgical procedure of the infected foot wounds (7 minor ray amputations, 2 wound debridements). All resultant wounds were ray amputation wounds over the metatarsals, except for one wound over the plantar midfoot. Wound sizes ranged from 2 cm x 4 cm x 4 cm to 11 cm x 4 cm x 8 cm. Median duration from surgery to initialization of NPWTi-d was 2 days (range, 1-22 days). Only 1 case reported a leak in NPWTi-d, which was resolved with minor adjustments and without changing the dressing in its entirety; no incidents of blockage were encountered. None of the patients required repeat surgical debridement during index hospitalization, and full epithelialization was achieved in 88.9% of patients.

Conclusions: The waterfall technique ensures placement of the NPWTi-d tubing pad in a dependent position to improve flow of instillation fluid with minimal risk of leakage or blockage.