External pancreatic fistula as a sequel to management of acute severe necrotizing pancreatitis

Background/aims: External pancreatic fistula (EPF) is a common sequel to surgical or percutaneous intervention for infective complications of acute severe pancreatitis. The present study was aimed at studying the clinical profile, course and outcome of patients with EPF following surgical or percutaneous management of these infective complications.

Methods: A retrospective analysis of clinical data of patients with EPF following intervention (surgical or percutaneous) for acute severe pancreatitis managed between January 1989 and April 2002 recorded on a prospective database was done. Univariate analysis of various factors (etiology, imaging findings prior to intervention, fistula characteristics and management) that could predict early closure of fistula was performed.

Results: Of 210 patients with acute severe pancreatitis, 43 (20%) patients developed EPF (mean age 38 (range 16-78) years, M:F ratio 5:1) following intervention for infected pancreatic necrosis (n=23) and pancreatic abscess (n=20) and constituted the study group. The fistula output was categorized as low (<200 ml), moderate (200-500 ml) and high (>500 ml) in 29 (67%), 11 (26%) and 3 (7%) patients, respectively. Fifteen patients (35%) had morbidity in the form of abscess (n=5), bleeding (n=1), pseudoaneurysm (n=2) and fever with no other focus of infection (n=7). Spontaneous closure of the fistula occurred in 38 (88%) patients. The average time to closure of fistula was 109+/- 26 (median 70) days. Fistula closed after intervention in 5 patients (2 after endoscopic papillotomy, 1 after fistulojejunostomy and 2 after downsizing the drains). Of the 38 patients with spontaneous closure, 9 (24%) patients developed a pseudocyst after a mean interval of 123 days of which 7 underwent surgical drainage of the cyst. Univariate analysis of various factors (etiology, imaging findings prior to intervention, fistula characteristics and management) failed to identify any factors that could predict early closure of fistula.

Conclusions: EPF is a common sequel following intervention in acute severe pancreatitis. The majority of these are low output fistulae and close spontaneously with conservative management. One-fourth of patients with spontaneous closure develop a pseudocyst as a sequel, requiring surgical management.