Prophylactic Negative Pressure Wound Therapy (VAC) in Gynecologic Oncology (G.O.)

Overview

A prospective controlled randomized study aimed to prospectively evaluate, the impact and effectiveness of clean incision prophylactic vacuum negative pressure therapy on wound healing (ciNPWT) in women at high risk of developing wound complications who undergo major gynecologic surgery. Gynecologic Oncology patients appear to be more at risk of developing wound complications than the general surgery population, reaching infection rates of 36 vs. 24 % that become 40 and 60% for obese and morbidly obese patients, respectively. Data about the use of ciNPWT are few, controversial and are of poor quality. No randomized, controlled trials have yet been reported in support of the use of ciNPWT in the gynecologic population.

Wound complications in patients undergoing surgery for malignancies have a negative impact on quality of life and, in addition, are associated with an increase of the duration of hospital stay, imparting a significant socio-economic burden. Several approaches have been proposed to reduce the wound complications rate without success. Instead, a novel and promising method has been employed which utilizes prophylactic negative pressure wound therapy placed over clean and closed surgical incisions immediately after surgery (ciNPWT). In a recent meta-analysis across studies including all types of wounds and surgeries, ciNPWT was observed to reduce by 29.4 % the incidence of SSI and the odds of SSI. In the same meta-analysis, while limiting attention to general abdominal surgery alone, the weighted average of the selected studies reported a reduction in wound complications of 10.43% (13.54% vs 23.97%) for the ciNPWT group compared with controls which was a significant benefit. This study is a prospective multi-centre controlled randomized trial, where after gynecologic oncologic laparotomic surgery and standard abdominal wall closure (if inclusion criteria result satisfied), patient is randomized to one of the two arms of the study: ARM A (sperimental): ciNPWT ARM B ( control): standard dressing. For women in arm A: prophylactic ciNPWT therapy entails placement of the device over a closed incision immediately post-operatively. The device may be left in place with no additional intervention for up to 7 days. The use of the device does not require specialty care services or continued hospitalization. For women in arm B: standard dressing should be changed every 2 days after sterile medication. People will be visited after 7 day of VAC-therapy (first visit) , discharge time (second visit or coincidence with the first visit), after 15 days from surgery (third visit for agraphis removal), after 30 days from surgery (fourth visit). Sample size determination. A review of previous literature suggests that the incidence of wound-SSI is about 35% in G.O. patients. We assume that the use of ciNPWT could be linked to an wound-SSI incidence of 15% Setting a two-sided α=0.05 and power = 80%, the sample size is N=164 subjects. A dropout rate of 20% is added, reaching a final sample size of N=196 subjects (98 subjects per arm). The primary objective will be achieved calculating and comparing the proportions of wound-SSI in the two arms. The comparison will be performed with a Chi-squared test. The same test will be applied to the comparisons of final and intermediate wound healing rates. The comparison of the proportion of wound complications and the proportion of patients in need of antibiotics will be achieved with a Chi-squared test, as well. Comparison of the time of operating room required to apply the dressings, hospital stay and time to adjuvant therapies will be performed with a T-test (if data are normally distributed) or with the Wilcoxon test (if data are not normal). A p-value \<0.05 will be considered statistically significant. All patient data will be collected and managed using an electronic database anonymously.