Prospective Validation of the Pancreatic Fistula Risk Classification by the International Study Group for Pancreatic Surgery (PARIS trial).

Objective: The aim of this study was a prospective validation of the recently established ISGPS pancreas classification as a parenchymal risk classification system for pancreatic fistula after pancreatoduodenectomy.

Summary background data: Postoperative pancreatic fistula (POPF) is the major driver for complications after partial pancreatoduodenectomy (PD). Recently, the International Study Group for Pancreatic Surgery (ISGPS) published a pancreas classification containing the parameters main pancreatic duct diameter (MPD) and pancreatic texture to help assess the risk of POPF development following pancreatoduodenectomy.

Methods: From January 2020 to July 2021, 271 patients receiving elective PD were included after informed consent. The postoperative course was documented prospectively up to postoperative day 30. Among the pancreas characteristics, MPD and pancreatic texture were assessed intraoperatively at the pancreatic resection margin and the pancreatic glands were assigned to one of the four pancreas classes according to the ISGPS (A to D). The primary endpoint was POPF according to the updated ISGPS definition. Secondary endpoints comprised other post-PD morbidity and mortality.

Results: Of 271 patients, 264 had available data according to the ISGPS pancreas classification. Of those, 78 were assigned to class A (30%), 53 to class B (20%), 50 to class C (19%) and 83 to class D (31%). POPF occurred in 54 of 271 patients (19.9%). The 30-day mortality was 7/271 (2.6%), with 6/7 having developed POPF (86%). POPF rates within the classes A, B, C and D were 9.0%, 11.3%, 20.0% and 37.4%, respectively (P<0.001). In the univariable regression analysis, only patients in pancreas class D demonstrated a significantly higher risk for POPF when compared to class A (OR 6.05, 95%-CI: 2.6-15.9, P<0.001). In the multivariable regression model, patients in class D had a significantly higher risk for POPF compared to class A (OR 3.45, 95%-CI: 1.15-11.3, P=0.032). The model comprised Body Mass Index, surgery duration, microscopic fibrosis and the ISGPS pancreas classification, demonstrating an AUC-value of approximately 0.82 when tested on the PARIS dataset.

Conclusion: This prospective trial shows that the ISGPS pancreas classification is valid. Patients in risk class D are prone to POPF independently of other factors. Therefore, all future publications on pancreatic surgery should report the risk class according to the ISGPS pancreas classification to allow for a better comparison of reported cohorts.