Clinical and Financial Validation of the International Study Group for Pancreatic Surgery (ISGPS) Definition of Post-pancreatectomy Acute Pancreatitis (PPAP)

OBJECTIVE: To validate the International Study Group for Pancreatic Surgery (ISGPS) definition and grading system of post-pancreatectomy acute pancreatitis (PPAP) after pancreatoduodenectomy (PD). BACKGROUND: In 2022, the ISGPS defined PPAP and recommended a prospective validation of its diagnostic criteria and grading system. METHODS: This was a prospective, international, multicenter study including patients undergoing PD at 17 referral pancreatic centers across Europe, Asia, Oceania, and the United States. PPAP diagnosis required the following 3 parameters: (1) postoperative serum hyperamylasemia /hyperlipasemia (POH) persisting on postoperative days 1 and 2, (2) radiologic alterations consistent with PPAP, and (3) a clinically relevant deterioration in the patient's condition. To validate the grading system, clinical and economic parameters were analyzed across all grades. RESULTS: Among 2902 patients undergoing PD, 7.5% (n=218) developed PPAP (6.3% grade B and 1.2% grade C). POH occurred in 24.1% of patients. Hospital stay was associated with PPAP grades [no POH/PPAP 10 days [interquartile range (IQR): 7-17] days, grade B 22 days (IQR: 15-34) days, and grade C 43 days (IQR: 27-54) days; P <0.001], as well as intensive care unit admission (no POH/PPAP 5.4%, grade B 12.6%, grade C 82.9%; P <0.010), and hospital readmission rates (no POH/PPAP 7.3%, grade B 16.1%, grade C 18.5%; P <0.05). Costs of grade B and C PPAP were 2 and 11 times greater than uncomplicated clinical courses, respectively ( P <0.001). CONCLUSIONS: This first prospective, international validation study of the ISGPS definition and grading system for PPAP highlighted the relevant clinical and financial implications of this condition. These results stress the importance of routine screening for PPAP in patients undergoing PD.