Clinical significance of postoperative acute pancreatitis after pancreatoduodenectomy and distal pancreatectomy

Background: The definition of postoperative acute pancreatitis as a specific complication of pancreatic surgery was proposed in 2016. Its presence and relevance have not been established, especially after a distal pancreatectomy. Methods: Medical records of 319 patients who underwent pancreatoduodenectomy or distal pancreatectomy were analyzed. Postoperative acute pancreatitis was defined as an increase in serum amylase activity greater than the upper normal limit on postoperative day 1, according to Connor's definition of postoperative acute pancreatitis. Results: Postoperative acute pancreatitis occurred in 63.4% of 153 of the patients undergoing pancreatoduodenectomy and 65.7% of the 166 undergoing distal pancreatectomies. Patients who developed postoperative acute pancreatitis after pancreatoduodenectomy experienced an increase in the rate of morbidity (22.7% vs 7.1%; P = .0137), including postoperative pancreatic fistula (18.6% vs 1.8%; P = .024), resulting in greater postoperative stays (21 days vs 17 days; P = .0008). Postoperative acute pancreatitis in association with an increased serum C-reactive protein ≥18.0 mg/dL (which we defined as a clinically relevant postoperative acute pancreatitis) more strongly indicated the occurrence of severe complications (P = .0032) and was an independent predictor of postoperative pancreatic fistula after pancreatoduodenectomy (odds ratio, 3.03; P = .0448). Patients who developed postoperative acute pancreatitis after distal pancreatectomy experienced similar postoperative courses regarding morbidity and the duration of postoperative stay. Conclusion: The clinical relevance of postoperative acute pancreatitis differs after a pancreatoduodenectomy versus a distal pancreatectomy. The development of effective strategies for preventing postoperative acute pancreatitis might improve surgical outcomes after pancreatoduodenectomy.