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.

Key inclusion criteria BMI greater than or equal to 30 kg/m2 at less than or equal to 22
weeks of gestation Subject is laboring Subject is having an unplanned cesarean section
Subject will have Pfannenstiel Skin Incision Subject has the ability to take a picture and
email it to a secure account Subject receives prenatal care in the University of
Pennsylvania health system and plans to follow up postpartum in the system Subject is
greater than or equal to 18 years of age

Key exclusion criteria Subject cannot read or speak English Subject is not 18 years of age
Subject does not have ability to send a picture by email Subject has preexisting diabetes
mellitus (Type 1 or Type 2) , is using chronic steroids or immune-suppressants, OR being
actively treated for a malignancy Subject is undergoing a scheduled cesarean section
Subject is allergic to silver