PROphylactic Wound VACuum Therapy to Decrease Rates of Cesarean Section in the Obese Population

Objectives To evaluate whether there is a decrease in wound complications among obese patients who are treated with closed incision NPWT versus standard post cesarean section wound care protocol.

Primary outcome variable(s) The primary outcome variable is wound complications defined as any readmission for a wound issue within four weeks of discharge, infection, or wound breakdown.

Secondary outcome will look at patient quality of life among those with NPWT versus usual care arm.

A survey addressing pain, breast feeding questions and ability to perform activity of daily living will be administered during the inpatient stay and at the postpartum visit.

Background Obesity, defined as a body mass index (BMI) 30kg/m2, continues to be a growing epidemic in the United States. According to National Center for Health Statistics Data1, almost one third of adults and 17% of youth were obese in 2009-2010. Furthermore, non-Hispanic Blacks have the age-adjusted rates of obesity (49.5%). In a study by Chu et al analyzing data from 26 states in the Pregnancy Risk Assessment Monitoring System (PRAMS) database, 20% of women who delivered were obese and in certain ethnic and insurance subgroups, the rates were as high as 33%. In 2008, according to reports by the Pennsylvania State statistics, the rates of obesity in the city of Philadelphia were as high as 64%. Multiple studies have demonstrated the increased risks for diabetes, hypertension and adverse pregnancy outcomes (APO) during pregnancy in the obese population. In addition, obesity is a well established independent risk factor for the development of a wound complication or infection after a cesarean delivery, with rates ranging from 10-15% . Certain measures such as antibiotic prophylaxis and closure of the subcutaneous space are techniques that have demonstrated a decreased incidence of wound disruption. Currently no randomized controlled trials have looked at the effects of surgical approach or choice of abdominal incision in the obese or extremely obese woman undergoing cesarean delivery. However, the few retrospective studies that have addressed this issue have demonstrated mixed results. Given the paucity of randomized controlled trials evaluating the prevention of wound complications in obese women undergoing cesarean delivery, a recent review by Tipton emphasized the necessity for such trials to evaluate methods with which to improve postoperative wound care and healing in this high risk cohort. In the past decade, negative pressure wound therapy (NPWT) has become accepted in the treatment of expediting healing of open wounds 15-18. NPWT is a method in which a vacuum device is placed on the wound in order to remove excess interstitial fluid, increase tissue vascularity, decrease bacterial colonization, and place mechanical stress on adjacent wound edges which aids in wound contractility and closure. Therefore, the positive effects of NPWT on open wounds have been well studied and established. Recent studies have been performed to assess a potential effect of NPWT on closed incisions non-obstetric fields. A recent study by Grauhan et al compared the effects of NPWT over closed sternotomy incisions in obese patients compared to conventional sterile wound dressing and noted a significant reduction in the rates of wound infection in those treated with NPWT.

Another study by Vargo assessed the effects of NPWT on closed incisions in patients undergoing abdominal therapy compared to a historical control also noted a decreased wound infection rate and no evidence of skin necrosis. In contrast, a recent study by Masden et al. looked at rates of infection and dehiscence in patients with multiple comorbidities status post predominantly lower extremity wounds and did not appreciate a difference between the NPWT group and dry dressing group24. Therefore, the need for further studies assessing the benefits of NPWT on various anatomical sites has been clearly established.