Open abdomen therapy with vacuum-assisted wound closure and mesh-mediated fascial traction

Abstract: Introduction:
Several life-threatening intra-abdominal conditions may be treated with open abdomen (OA) therapy. Potential complications to OA treatment include damage to the exposed bowel resulting in enteric fistulas, and inability to close the abdomen afterwards resulting in large ventral hernias. Vacuum-assisted wound closure and mesh-mediated fascial traction (VAWCM) is a novel technique for temporary closure of an OA, intended to increase the chances of subsequent delayed primary fascial closure without increasing the risk of complications. A classification system for the OA has been proposed by the World Society of the Abdominal Compartment Syndrome (WSACS), aimed at improving OA therapy and facilitating clinical research, but has not previously been evaluated.

Aims:
The aims were to study:
- Short-term clinical outcome of OA therapy with VAWCM with regards to fascial closure and factors associated
with failure of fascial closure, mortality, morbidity and possible technique-related complications.
- One-year clinical outcome of OA therapy with VAWCM with regards to the incidence of incisional- and parastomal hernias, abdominal wall discomfort and frequency of hernia repair operations after one year.
- Validity and reliability of the 2013 OA classification system by WSACS and to propose instructions for use with the classification.
- Physiological effects of vacuum therapy (VAWC) in an OA with regards to the extent of negative pressure reaching the bowel, the efficacy of the VAWC system in draining fluid from the abdominal cavity and whether paraffin gauzes can be effectively used as pressure isolation when placed between the vacuum source and the bowel.

Results/conclusions :
- VAWCM provided a high fascial closure rate after long-term OA treatment in mostly elderly, non-trauma patients. Technique-related complications were few and fistula incidence and mortality were similar to other studies.
- Incisional hernia incidence one year after OA therapy with VAWCM was high. Most hernias were small and asymptomatic and few required surgical repair during the first year.
- The validity and reliability analysis of the OA classification system by WSACS showed that each patient’s most complex OA grade, worsening OA grade without later improvement, as well as development of grade C (enteric leak) or grade 4 (entero-atmospheric fistula) were associated with worse outcome (mortality and failure of fascial closure). Every effort should be made to prevent patients from ascending to a more complex OA grade, to try to repair enteric leaks and to avoid enteroatmospheric fistulas.
- Negative pressure reaching the bowel during VAWC therapy was limited, regardless of negative pressure setting. Reduced therapy pressure did not lead to reduced pressure at the bowel surface. The system drained the abdominal cavity completely of fluid. Paraffin gauzes were of limited value as a means of isolation against pressure propagation.