Postpancreatectomy Acute Pancreatitis After Pancreaticoduodenectomy

Objective: This study aimed to characterize postpancreatectomy acute pancreatitis (PPAP) after pancreaticoduodenectomy (PD) in a high-volume center. Background: The International Study Group for Pancreatic Surgery (ISGPS) has recently proposed a new definition and grading scale of PPAP, but specific studies are lacking. Methods: Patients who underwent PD from 2020 to 2021 were retrospectively reviewed. PPAP was defined based on the International Study Group for Pancreatic Surgery definition: sustained elevation of serum amylase levels for least the first 48 hours postoperatively and radiologic alterations consistent with PPAP. Results: Among a total of 716 patients who were finally analyzed, PPAP occurred in 152 (21.2%) patients. Patients with PPAP were associated with significantly higher incidences of postoperative pancreatic fistula (POPF) (40.8% vs 11.7%, P <0.001), major complications (13.8% vs 6.6%, P =0.004), and biliary leak (11.8% vs 4.6%, P =0.001). Among them, 8 patients developed grade C PPAP leading to organ failure, reoperation, or death. Patients developing PPAP alone also demonstrated a statistically significantly increased rate of major complications than those without PPAP or POPF. In contrast, no differences were found in postoperative outcomes in patients with POPF in terms of whether they were associated with PPAP. Conclusion: PPAP is a distinct complication after PD with distinctive clinical outcomes. A part of PPAP presents as an inflammatory process in the early postoperative period but sometimes could lead to necrotizing pancreatitis or other severe clinical scenarios, and another part of PPAP would lead to anastomotic failure that accounts for a great proportion of POPF occurrence.