Entero-atmospheric fistula migration: a new management alternative for complex septic open abdomen

**Background:** The open abdomen (OA) technique is a surgical strategy used in life-threatening conditions including intra-abdominal bleeding, prevention or treatment of intra-abdominal hypertension, and management of intra-abdominal sepsis. Temporary abdominal closure (TAC) aims to create tension-free closure without increasing intra-abdominal pressure. Negative pressure wound therapy (NPWT) has become a key TAC method, but entero-atmospheric fistulas (EAF) remain a major challenge. EAF formation is one of the most devastating complications of prolonged OA management, predisposing patients to intra-abdominal adhesions and frozen abdomen. The authors describe two new management alternatives for the complex septic abdomen with EAF.

**Methods:** The first technique is described in a 32-year-old woman who underwent complex gastric bypass requiring two re-interventions (postoperative days 5 and 9) due to severe bowel adhesions. At the last intervention, an EAF was noted (Björck grade IIIb). The acute care surgery team isolated the fistula with a Foley catheter and used a "donut technique" to isolate the EAF over a cropped ABThera NPWT system. A port-o-vac drain was placed circling both the inner part of the donut and the Foley catheter, exiting through the abdominal wall. A polypropylene mesh was sutured to the fascia with a running suture at the midline to promote tension. NPWT was applied at 125 mm Hg (16.7 kPa). The patient was kept sedated and paralyzed with neuromuscular blockade to avoid abdominal hypertension. Early parenteral nutrition was started at 2086 kcal/day, and octreotide was prescribed at 100 µg subcutaneously every 8 hours for 10 days. The second technique involved off-label use of the Flexi-Seal (ConvaTec) fecal incontinence control device to divert enteric effluents away from the skin in 5 consecutive patients with frozen abdomen and EAF or collapsed colostomies.

**Key Results:** In the first case, the leukogram began falling to regular levels after the initial procedure. At the first NPWT change on day 4, very little enteric leak was captured by the port-o-vac drain. After 8 days of effective dynamic fascial treatment, the EAF remained controlled by the Foley catheter with no contamination observed. At 12 days, the abdomen was clean with granulation tissue. The Foley catheter was removed, non-absorbable sutures were placed at the fistula hole, and the port-o-vac drain was kept guarding the former EAF site. Abdominal fascia and skin were completely closed at the end of 12 days with total resolution of the EAF. The port-o-vac drain was removed within the next 4 days. Oral nutrition started after the third day following the last surgical intervention, and the patient was discharged home on the tenth day after the last surgical procedure. For the Flexi-Seal technique, successful intestinal effluent diversion was achieved in all 5 consecutive patients, allowing abdominal skin to recover faster in OA cases with EAF and permitting ischemic/collapsed stomas to heal or buying time for new intervention in critical patients.

**Clinical Implications:** The intra-cavitary donut technique represents a novel strategy that allows NPWT to work on the abdominal fascia without leakage from the EAF, effectively "excluding" the fistula site from the rest of the abdomen. This approach transformed an EAF into an enteric fistula by migrating the fistula laterally rather than at the midline, facilitating abdominal closure. The authors propose a treatment algorithm for migrating fistula using the intra-cavitary donut or EAF diversion device via the stoma. They note that NPWT with continuous fascial traction has proven its role as an efficient means to achieve primary fascial closure after OA, and a 2014 European study concluded NPWT to be the best option currently available to treat grade 3 OA with an EAF. The authors acknowledge that to their knowledge there are no clinical studies corroborating the use of the Flexi-Seal device via a stoma, but its use was reasonable, caused no harm, and produced remarkable results.