The Effect of an Invasive Strategy for Treating Pancreatic Necrosis on Mortality: a Retrospective Multicenter Cohort Study

Background Infected acute necrotic collections (ANC) and walled-off necrosis (WON) of the pancreas are associated with high mortality. The difference in mortality between open necrosectomy and minimally invasive therapies in these patients remains unclear. Methods This retrospective multicenter cohort study was conducted among 44 institutions in Japan from 2009 to 2013. Patients who had undergone invasive treatment for suspected infected ANC/WON were enrolled and classified into open necrosectomy and minimally invasive treatment (laparoscopic, percutaneous, and endoscopic) groups. The association of each treatment with mortality was evaluated and compared. Results Of 1159 patients with severe acute pancreatitis, 122 with suspected infected ANC or WON underwent the following treatments: open necrosectomy (33) and minimally invasive treatment (89), (laparoscopic three, percutaneous 49, endoscopic 37). Although the open necrosectomy group had a significantly higher mortality on univariate analysis (p = 0.047), multivariate analysis showed no significant associations between open necrosectomy or Charlson index and mortality (p = 0.29,p = 0.19, respectively). However, age (for each additional 10 years,p = 0.012, odds ratio [OR] 1.50, 95% confidence interval [CI] 1.09-2.06) and revised Atlanta criteria-severe (p = 0.001, OR 7.84, 95% CI 2.40-25.6) were significantly associated with mortality. Conclusions In patients with acute pancreatitis and infected ANC/WON, age and revised Atlanta criteria-severe classification are significantly associated with mortality whereas open necrosectomy is not. The mortality risk for patients undergoing open necrosectomy and minimally invasive treatment does not differ significantly. Although minimally invasive surgery is generally preferred for patients with infected ANC/WON, open necrosectomy may be considered if clinically indicated.