Negative pressure wound therapy for the open abdomen

Mortality of 22% (95% confidence interval [CI] 18 to 28) for negative pressure wound therapy (NPWT), 33% (95% CI 25 to 42) for packing, 30% (95% CI 24 to 37) for mesh, 30% (95% CI 23 to 36) for zipper, 28% (95% CI 20 to 37) for Bogota bag and 16% (95% CI 5 to 30) for Wittmann patch were reported in the meta-analysis of 4,303 patients. Mortality of 26% (48 out of 187) for patients treated by NPWT and 29% (55 out of 187) for patients treated by other temporary abdominal closure techniques (p=0.40, matched pair analysis) were reported in the non-randomised comparative study of 578 patients. Mortality of 30% (33 out of 111) was reported in the case series of 111 patients.

Fistulae were reported in 7% (95% CI 5 to 9) of patients treated by NPWT compared with 13% (95% CI 5 to 23) treated by zipper, 11% (95% CI 6 to 16) treated by packing, 8% (95% CI 5 to 10) treated by mesh, 8% (95% CI 2 to 16) treated by Bogota bag and 3% (95% CI 1 to 5) treated by Wittmann patch in the meta-analysis of 4,303 patients. Intestinal fistulae were reported in 8% (15 out of 187) of patients treated by NPWT and in 10% (18 out of 187) of patients treated by other techniques (p=0.58, matched pair analysis) in the non-randomised comparative study of 578 patients. Intestinal fistulae that were considered possibly to be related to NPWT were reported in 7% (8 out of 111) of patients in the case series of 111 patients (7 occurred during treatment and 1 after treatment).

Intestinal failure (defined as the need for parenteral nutrition for more than 28 days) was reported in 15% (28 out of 187) of patients treated by NPWT and in 15% (28 out of 187) of patients treated by other techniques (p=1.00, matched pair analysis) in the non-randomised comparative study of 578 patients.

Abscess was reported in 4% (95% CI 2 to 7) of patients treated by NPWT compared with 16% (95% CI 4 to 19) treated by zipper, 12% (95% CI 1 to 31) treated by Bogota bag, 9% (95% CI 5 to 13) treated by mesh, 7% (95% CI 2 to 16) treated by packing and 2% (95% CI 0.1 to 8) treated by Wittmann patch, in the meta-analysis of 4,303 patients. Abdominal abscess was reported in 5% (5 out of 111) of patients in the case series of 111 patients (1 occurred during treatment and 4 after treatment).

Intervention to control bleeding was reported in 12% (23 out of 187) of patients treated by NPWT and in 17% (31 out of 187) of patients treated by other techniques (p=0.25, matched pair analysis) in the non-randomised comparative study of 578 patients.

The specialist advisers stated that it could sometimes be difficult to remove the foam component of NPWT because of granulation tissue that had anchored it to the wound. In addition to the adverse events described above, the specialist advisers drew attention to pain as an adverse event reported in the literature. They listed theoretical adverse events as bowel perforation, and in the longer term an increased risk of cancerous cell regeneration.