Simplified negative pressure wound therapy: clinical evaluation of an ultraportable, no-canister system

Abstract

The aim of this study was to evaluate a prototype negative pressure wound therapy (NPWT) system that has been developed to simplify NPWT for wounds at the lower end of the acuity scale. The new device has a single preset pressure of -80 mmHg, is single use and operates without an exudate canister. The disposable NPWT system (PICO™) was tested in a prospective, non-comparative, multicentre clinical trial to assess device functionality and clinical acceptance. Twenty patients were recruited for a maximum treatment period of 14 days. The NPWT devices were fitted with data log chips to enable longitudinal assessment of negative pressure and leak rates during therapy. Sixteen (80%) patients had closed surgical wounds, two (10%) patients had traumatic wounds and two (10%) patients received meshed split thickness skin grafts. The mean study duration was 10·7 days (range: 5-14 days) and the mean dressing wear time per individual patient was 4·6 days (range: 2-11). Fifty-five percent of wounds had closed by the end of the 14-day study or earlier, with a further 40% of wounds progressing to closure. Real-time pressure monitoring showed continuous delivery of NPWT. Three cases are discussed representing different wound locations and different patient factors that can increase the risk of post-surgical complications. Clinical studies of the disposable NPWT system confirmed the ability of the simplified single-use device to function consistently over the expected wear time. The anticipated reduced costs, ease of use and increased mobility of patients using this system may enable NPWT benefits to be available to a greater proportion of patients.

Keywords: Closed surgical incision; Negative pressure wound therapy; Portable; Postoperative care; Wound healing.

Figure 1

Simplified disposable negative pressure wound therapy (NPWT) system. (A) Pump and dressing: the ultraportable pump (PICO™, Smith & Nephew) is single use and disposable after 7 days of continual use, operates without a canister and is 85 × 85 × 25 mm in size. The device simplifies NPWT by replacing the exudate canister with a high evaporative loss dressing, which has a wear time of up to 7 days and can be replaced if necessary by detaching at the device. (B) Illustration of fluid flow through the layers of the dressing and evaporative fluid loss through the high moisture vapour transmission rate (MVTR) upper layer.

Figure 2

Reference wound progression at treatment discontinuation. Treatment was discontinued either at the end of the study period (14 days) or earlier if the wound was deemed closed. Mean treatment duration was 10·7 days.

Figure 3

Case 1 – Post‐surgical wound following breast reconstruction. A 41‐year‐old woman recently received radiotherapy following a mastectomy. The patient underwent surgery for breast reconstruction and tissue expander placement. (A) The wound measured 15 cm in length and 0·5 cm in width. Note that the closed incision is raised above the level of surrounding skin. (B) Patient with NPWT dressing system in place on first assessment (day 1). (C) Post‐surgical wound after dressing removal, day 11. The surgical incision is closed, there is no exudate and the incision is flat. Note the tunnelled IV site wound that remains raised. The device was changed after 7 days.

Figure 4

Case 2 – Post‐surgical wound following a hip replacement procedure. A 65‐year‐old woman with hypertension, diabetes, high body mass index (BMI) and osteoarthritis who underwent surgery for a hip replacement. (A) Hip implant wound immediately after surgery was closed with sutures and Steri‐Strips™. (B) Negative pressure wound therapy (NPWT) system in place over the hip on day 1. (C) Wound progressing to closure on day 7 before being discontinued on the ninth day. The device was changed after 7 days.

Figure 5

Case 3 – Post‐surgical wound following revision knee surgery. A 48‐year‐old woman had undergone two previous procedures to the knee. (A) Wound immediately post‐surgery was closed with sutures and Steri‐Strips^TM prior to application of disposable negative pressure wound therapy (NPWT) system. (B) NPWT dressing system in place at day 3. (C) Surgical wound at dressing change on day 10. The wound was deemed to be closed and therapy discontinued at day 10. The device was changed after 6 days.