Abstract

Introduction

Abdominal compartment syndrome, damage control surgery in traumatology, diffuse peritonitis and wound dehiscence are the most common indications for applying the open abdomen (OA) treatment concept. The requirements for the ideal temporary abdominal closure (TAC) are numerous and include the following: to protect and keep the abdominal content in place, to prevent adherences to the abdominal wall, to reduce oedema of the intestinal wall and to drain the abdominal cavity. In addition, the TAC must prevent lateral retraction of the fascia in order to obtain early secondary closure, and finally it should not lead to serious complications, such as enteroatmospheric fistula formation.

Several methods have been developed to meet the criteria of the ideal TAC. Overall, they can be divided into three different types. The first is skin‐closing techniques that include the simple running suture of the skin and the Bogota Bag. The major concerns with this method are the lateral retraction of the abdominal fascia, which later may lead to large incisional hernias. Furthermore, it does not allow effective drainage of the abdominal cavity. The second includes Wittmann Patch (WP) and polypropylene mesh, which provide high fascial closure rates and are often recommended when using long‐term OA treatment; however, they do not provide effective drainage. The third is negative pressure applications using Barker’s vacuum packing technique (BVPT) and the commercial abdominal dressing systems, V.A.C.^® Abdominal Dressing System and ABThera™ Open Abdomen Negative Pressure Therapy (OA NPT) System. When properly used, these systems provide high rates of secondary fascial closure and provide effective drainage of the abdominal cavity. However, there has been some concern on the development of enteroatmospheric fistulas.

This study is a review of our results with the commercially available NPT systems (V.A.C.^® Abdominal Dressing System and ABThera™ OA NPT System) using a new method of applying the system, called the narrowing technique. The primary endpoints were fascial closure rate, presence of enteroatmospheric fistulas and 30‐day mortality rates.

Patients and methods

The records of all the patients treated with an OA in the surgical departments at the Odense University Hospital and at the Esbjerg Hospital during a 5‐year period between May 2008 and October 2012 were retrospectively reviewed. The hospital at Odense provides primary medical care for approximately 350 ۰۰۰ inhabitants and is a tertiary referral centre for 1·۳ million inhabitants. The Esbjerg Hospital provides primary medical care for approximately 400 ۰۰۰ inhabitants. Patients were identified from the hospitals’ central patient register systems (register was searched for NPT treatment and all patients who were not treated with an OA were excluded). Demographic data including age and the American Society of Anesthesiologists (ASA) Physical Status classification score were registered. The indications for using NPT, number of dressing changes and the duration of treatment were registered. Secondary closure of the fascia at the end of treatment and development of fistula during the treatment were also registered. Death within 30 days of initiating the OA treatment was also noted. In the observation period, we used both commercialised NPT systems (V.A.C.^® Abdominal Dressing System and ABThera™ OA NPT System, KCI, San Antonio, TX). We did not differentiate between the two systems used in this study, as we have been using both systems as standard at different times in the observation time.

NPT application

Using either system, the intestines, including the lateral aspects, were covered by a visceral protective layer (protective non‐adherent and/or fenestrated layer). For the narrowing technique, the first layer of foam was placed flat in the wound, which included 5 cm underneath the fascia. A minimum of one piece of foam was folded and placed in the laparostoma prolapering above the laparostoma​. Then we applied the occlusive drape loosely in 10–۱۵ cm wide strips. During the application of the negative pressure, the fascial edges were approximated manually towards the midline. This was done to make the laparostoma opening as narrow as possible. We used a standard negative pressure of −۱۲۵ mmHg, but when an anastomosis was performed, the negative pressure was sometimes reduced to as low as −۲۵ mmHg, because lowering the pressure will protect the anastomosis, and a pressure of −۲۵ mmHg was high enough to prevent the lateralisation of fascial edges. The dressing was changed with an intended interval of 48 hours depending on the clinical condition, with earlier changes as an option. Each dressing change was performed at the operation theatre, and the patient was in general anaesthesia at maximum relaxation. When the patient attained an improvement in general condition as judged by gastrointestinal and renal functions and a decline in inflammatory parameters, the fascia was successively closed with non‐resorbable single stitch sutures starting from the proximal to distal ends of the wound.

Schematic of negative pressure therapy (NPT) application.

Demonstration of the placement of first foam underneath the fascia.

Demonstration of the pushing of the fascial edges towards the midline when negative pressure was applied.

Final result of narrowing technique after the application of negative pressure therapy (NPT).

Results

In the period from May 2008 to October 2012, a total of 115 (72 males and 43 females) patients were treated with an OA. The median age was 68 years (range: 15–۸۷). The median ASA score was 4 (range: 1–۴) (Table ​(Table1).۱). The median of length of stay in hospital was 25 days (range: 1–۱۳۰) and that of an intensive care unit stay was 3 days (range: 0–۸۳).

The indications for an OA were diffuse peritonitis in 64 patients, scheduled second look in 22 patients, wound dehiscence in 19 patients and abdominal compartment syndrome in 10 patients. Our definition of abdominal compartment syndrome is intraabdominal pressure (IAP) of >20 mmHg and new organ dysfunction. We measured the IAP by bladder pressure. The median number of dressing changes before closure was 4 (range: 1–۳۶) and the median duration of NPT before closing the fascia was 7 days (range: 1–۷۵). The mortality rate was 17% (20/115). Of the 20 patients who died, 10 patients had been treated with an OA because of severe peritonitis, 6 patients because of second look, 2 patients with abdominal compartment syndrome and 2 patients with wound dehiscence. Secondary closure of the fascia was obtained in 92% (106/115) of the patients. However, none of the patients had undergone clinical, CT scan or ultrasonography as follow‐up. In nine patients, it was not possible to obtain closure of the fascia, and they received therapy for a median of 14 days (range: 7–۷۵) and a median of 5 (range: 2–۳۷) dressing changes. An enterosphincteric fistula had developed in 3·۵% (۴/۱۱۵) of the patients.

Discussion

It is important to keep in mind that this group of patients was critically ill and needed special attention with a multidisciplinary approach to stabilise the patient. This allowed us to obtain the earliest closure possible, which appears necessary for a high success rate of fascial closure and a low mortality rate. Another important factor was the progression in the stepwise closure at each NPT dressing change.

We found that using the narrowing NPT technique without any use of mesh or soft sutures during NPT to prevent the retraction of the abdominal wall gave high rates of fascial closure compared with the results of other studies that used NPT. Although sutures were used for closing the abdominal wall, we found that applying NPT without using soft sutures or mesh is easier and faster. Compared with other studies that used only NPT to prevent lateralisation of the abdominal wall, it was found that this study had higher closing rates. However, the patient population of this study was a very heterogeneous group treated for wound dehiscence and second look; one would expect it to be easier to close these wounds than those of severe peritonitis. The fistula rate of this study was also comparable to that of other studies that used NPT. A prospective observational study by Cheatham et al. showed a fistula development rate of 4% in 111 patients treated with NPT. In addition, Franklin et al. reported only 1 out of 19 patients developing a fistula. However, this patient spent 90 days in the intensive care unit and was critically ill (history of anastomotic leak, development of large ventral hernia, previous hernia repair with biological mesh and a protective ileostomy) and may have developed a fistula regardless of TAC method. A review article by Boele van Hensbroek et al. reported an overall fistula rate of 2·۹% for NPT compared with the higher rates of other TACs: 5·۷% (BVPT), 13·۸% (zipper) and 28% (loose packing). Furthermore, a more recent prospective observational study of 578 patients by Carlson et al. found that NPT patients were not more likely to develop a fistula compared with non‐NPT patients.

We found that it is easy to apply the NPT system with the narrowing technique, and also that this method caused less damage to the abdominal wall. The narrowing technique with the foam underneath the fascia was a new method to apply the NPT systems and may explain the high closure rates (92%) observed in the patient population of this study. Other NPT studies have reported closure rates between 69% and 89·۵%. Further studies need to be conducted to compare the different methods and to evaluate the long‐term outcomes.

Conflicts of Interest

Dr UTH presented as a faculty member during the 2013 International Surgical Wound Forum (ISWF), an annual educational event sponsored by Kinetic Concepts, Inc. (KCI). The article is part of a KCI‐funded educational supplement based on 2013 ISWF faculty presentations about wound care strategies using Negative Pressure Wound Therapy (V.A.C.^® Therapy and Prevena™ Incision Management System) over closed surgical incisions and Negative Pressure Therapy (V.A.C.^® Abdominal Dressing System and ABThera™ Open Abdomen Negative Pressure Therapy) to treat OAs. KCI assisted with the editorial review of the manuscript. Drs HTH, ME and NQ have no conflict of interest and have no financial relationship with KCI.