Mutual decision Walter Reed/U Maryland and Mesh Suture Inc.

This is a multisite randomized control proof-of-concept trial to evaluate the safety of Duramesh laparotomy closure in the trauma and emergency laparotomy setting. The study will be performed at University of Maryland Shock Trauma Center and Walter Reed National Military Medical Center. One hundred (100) patients will be randomized (2:1) to Duramesh laparotomy closure versus conventional suture closure.

After the patient has been confirmed to be a candidate for the trial, randomization will be performed in the operating room upon completion of the index abdominal procedure. Duramesh will be provided for patients assigned to the Duramesh treatment arm. Patients will be followed for 1 year following laparotomy closure at follow-up intervals of 1 month, 3 months, 6 months, and 12 months.

Primary Laparotomy Closure Treatment 1) Study Group - Duramesh Laparotomy Closure (DLC) Treatment 2) Control Group - Conventional Suture Closure (CSC)

Patients undergoing a midline laparotomy for trauma or emergency surgery will have their abdominal wall laparotomy incision closed with size 0 Duramesh suturable mesh. Patients randomized to conventional laparotomy closure will be closed using size

1 slowly-absorbing (PDS) single strand or looped suture, based on surgeon preference.

While it would be preferable to identify a single conventional suture to serve as the control group, polling of potential participating surgeons demonstrated a preference for both single strand and looped sutures to be available for use in the conventional suture closure group. Both Duramesh and conventional sutures will be placed using a standardized closure technique that incorporates 1cm wide bites and 1cm spacing, as this is the established technique for trauma and emergency laparotomy closure at both participating institutions. An effort to quantify suture to wound length ratio will be made in an effort to confirm standardization of closure technique between groups. The small-bites surgical closure technique popular in Europe has not been adopted by trauma and emergency surgeons at either institution given concerns related to early dehiscence and the inability to extrapolate the STITCH trial data to a US trauma population. The surgeons at both institutions do not believe it acceptable to generalize the European trial with a mean BMI of 24 to the United States population, nor do they believe it wise to close the abdominal wall with a 2-0 polydioxanone suture, as this technique trended towards a higher rate of acute fascial dehiscence (burst abdomen).

All patients will be assessed for post-operative complications ( i . e . , infection, seroma, hematoma), a t 1 , 3 , 6 , and 12 months p o s t o p e r a t i v e l y . Patient will also be assessed for incisional hernia formation at the same post-operative time points (1, 3, 6, 12 months). Hernia outcomes will be based on physical examination, with ultrasound used for any uncertainties. While surveillance imaging has been shown to be more sensitive for hernia detection, the primary purpose of this study is to compare the safety profile of Duramesh laparotomy closure to standard closure technique. Surveillance imaging for hernia identification is not a part of standard clinical practice at the participating study sites. The rate of clinically relevant hernias found on physical exam will be used to inform future efficacy studies, where routine surveillance imaging will be incorporated into the study design.

In addition to the patients undergoing primary laparotomy closure following an open trauma or emergency abdominal surgery, an additional subset of 20 patients undergoing delayed primary closure of an open abdomen will also be studied. These patients represent a particularly challenging clinical problem, for which there is no standard approach to repair. All 20 study patients undergoing delayed primary closure of an open abdomen will be closed with #1 or #2 Duramesh and followed according to the same post-operative protocol as those undergoing primary laparotomy closure. This subgroup is too small for randomization to provide useful data for comparison, and thus will be used to provide only a descriptive analysis of this early experience with delayed Duramesh closure of the open abdomen. The safety of Duramesh closure in this patient population can be extrapolated from the previously referenced experience of mesh strip closures in contaminated incisional hernias.

Inclusion Criteria:

• Midline laparotomy greater than 5 cm in length
• Urgent or emergent surgery following trauma
• Urgent or emergent surgery for diverticulitis
• Large or small bowel obstruction, acute abdomen, or intra-abdominal hemorrhage.
• Open abdomen after midline laparotomy.

Exclusion Criteria:

• Prior hernia repair or existing abdominal mesh
• Metastatic cancer
• Pregnancy
• Immunosuppression.

As per the sponsor wishes