Preventing Adverse Incisional Outcomes at Cesarean Multicenter Trial (Prevena-C)

Prophylactic Negative Pressure Wound Therapy in Obese Women at Cesarean: a Multicenter Randomized Trial

The Prophylactic Negative Pressure Wound Therapy in Obese Women at Cesarean Trial is a large pragmatic multi-center randomized clinical trial designed to evaluate the effectiveness, safety and cost-effectiveness of prophylactic negative pressure wound therapy (NPWT) - a closed, sealed system that applies negative pressure to the wound surface via a single-use, battery-powered, portable device - to decrease surgical site infections (SSIs) in obese women.

Experimental evidence suggests that NPWT promotes wound healing by removing exudate, approximating the wound edges, and reducing bacterial contamination. Obesity (body mass index [BMI] ≥30kg/m2) increases the risk for both cesarean delivery and SSIs compared to non-obese women. The increased risk of SSIs is in part due to the increased thickness of the subcutaneous space, allowing collection of exudates and increasing tension on wound edges, promoting the growth of bacteria, and leading to wound infection and breakdown. Thus, prophylactic NPWT may be particularly effective in this patient population. During the 5-year project period, investigators from 4 collaborating perinatal centers in the United Stated (two university and two community) will randomize 2850 obese women undergoing cesarean delivery to receive either prophylactic negative pressure wound therapy with the Prevena device or standard wound dressing. Women will be followed up to 30 days postoperatively to ascertain study outcomes. The primary outcome for the trial is superficial or deep SSI after cesarean according to the CDC's National Healthcare Safety Network definitions. The investigators will also assess other wound complications, adverse events potentially attributable to NPWT and cost-effectiveness as measured by incremental cost per case of SSI prevented and per quality-adjusted life year (QALY).

Women assigned to prophylactic NPWT will have the Prevena device applied and secured with fixation adhesion strips. The device will be monitored while the patient is in the hospital to confirm that it is functioning well. The device will be removed prior to discharge, typically on postoperative day 4, but longer for up to 7 days for patients who remain hospitalized.

Women assigned to standard care will receive routine postoperative wound dressing consisting of layers of gauze and adhesive tap. The dressing will be removed after 24 - 48 hours.

The Prevena NPWT system is a small, lightweight, portable suction device consisting of an electric motor-driven vacuum pump connected to a proprietary foam and adhesive dressing. It is supplied as a pump with a sterile dressing kit and two batteries. Different dressing sizes are available for transverse and vertical incisions ranging from 13 to 20 cm and more. The pump maintains negative pressure of -125 mmHg to the wound surface. The device is placed after skin closure.

Standard wound dressing is routine postoperative wound dressing consisting of layers of gauze and adhesive tape.

As defined according to the Center for Disease Control and Prevention's (CDC) National Healthcare Safety Network criteria.

Frequency of wound hematoma, seroma, separation (other wound complications). Hematoma, seroma, separation (2cm or more).

Number of Participants With a Composite of Any Wound Complication Including SSI, Hematoma, Seroma, Separation (2cm or More).

Frequency of a composite of any wound complication including SSI, hematoma, seroma, separation (2cm or more). SSI, hematoma, seroma, separation (2cm or more).

Number of Participants With Physician Office Visit, Emergency Room Visit, Attendance at Wound Clinic, Use Antibiotics, Hospital Readmission for Wound Related Problems (Measures of Healthcare Resource Utilization)

Frequency of physician office visit, emergency room visit, attendance at wound clinic, use antibiotics, hospital readmission for wound related problems (measures of healthcare resource utilization).

Number of Participants With Skin Blistering, Erythema, Wound Bleeding (Measures of Adverse Skin Events)

Based on economic analysis to be done along side trial. Results of the economic analysis will be published separately from the effectiveness and safety data.

Based on economic analysis to be done along side trial. Results of the economic analysis will be published separately from the effectiveness and safety data.

Based on combined cohort. Results of the risk factor analysis will be published separately from the effectiveness and safety data.

Inclusion Criteria Gestational age ≥23weeks BMI≥30 Pre-pregnancy or BMI at first prenatal visit Planned or unplanned cesarean delivery Exclusion Criteria: Non-availability for postoperative follow-up Contraindication to NPWT applicable to women undergoing cesarean: Pre-existing infection around incision site, Bleeding disorder, Therapeutic anticoagulation, Irradiated skin, Allergy to any component of the dressing (e.g. silver, acrylic, silicone, adhesive tape)

Mark KS, Alger L, Terplan M. Incisional negative pressure therapy to prevent wound complications following cesarean section in morbidly obese women: a pilot study. Surg Innov. 2014 Aug;21(4):345-9. doi: 10.1177/1553350613503736. Epub 2013 Sep 20.

Swift SH, Zimmerman MB, Hardy-Fairbanks AJ. Effect of Single-Use Negative Pressure Wound Therapy on Postcesarean Infections and Wound Complications for High-Risk Patients. J Reprod Med. 2015 May-Jun;60(5-6):211-8.

Bullough, L, Wilkinson, D., Burns, S, Wan, L, Changing wound care protocols to reduce postoperative caesarean section infection and readmission, Wounds , 2014 (10), 1 : 72 - 76. 46

Chaboyer W, Anderson V, Webster J, Sneddon A, Thalib L, Gillespie BM. Negative Pressure Wound Therapy on Surgical Site Infections in Women Undergoing Elective Caesarean Sections: A Pilot RCT. Healthcare (Basel). 2014 Sep 30;2(4):417-28. doi: 10.3390/healthcare2040417.

Tuuli MG, Liu J, Tita ATN, Longo S, Trudell A, Carter EB, Shanks A, Woolfolk C, Caughey AB, Warren DK, Odibo AO, Colditz G, Macones GA, Harper L. Effect of Prophylactic Negative Pressure Wound Therapy vs Standard Wound Dressing on Surgical-Site Infection in Obese Women After Cesarean Delivery: A Randomized Clinical Trial. JAMA. 2020 Sep 22;324(12):1180-1189. doi: 10.1001/jama.2020.13361.