External Validation of the ISGPS Complexity Grading System for Minimally Invasive Pancreatoduodenectomy

Objective: To validate the ISGPS complexity grading system for minimally invasive pancreaticoduodenectomy (MIPD). Background: Although concerns about patient safety persist, MIPD is gaining popularity. The ISGPS recently introduced a difficulty grading system to improve patient selection by aligning procedural complexity with surgeon and center expertise. Methods: Data from MIPD cases reported in the IGOMIPS registry (October 2019-February 2024) were analyzed, with severe postoperative complications as the primary outcome. Logistic regression was used to identify risk factors for complications. Results: Of the 771 MIPD cases, 426 (55.3%) were analyzed. A pancreatic duct size ≤3 mm was the only significant risk factor for severe complications (OR=2.22, P=0.0001). Most cases (n=255; 59.9%) were classified as grade C complexity, whereas 22 (5.1%) were classified as grade A. Severe postoperative complications increased with complexity (grade A, 31.8%; grade B, 36.3%; grade C, 48.6%; P=0.0091). For grade A complexity, the outcomes were consistent across surgeons and centers. Grade B outcomes were similar between grade B and C centers but superior to grade A centers. In grade C cases, outcomes were comparable between grade A and B centers, with improvements at grade C centers. Grade A ISGPS experience correlated strongly with mismatches between planned and performed procedures (grade A, 15.0%; grade B, 3.0%; grade C, 3.1%; P<0.0001), including total pancreatectomy (grade A, 11.5%; grade B, 1.2%; grade C, 3.1%; P=0.0005). Conclusions: The ISGPS complexity grading system effectively predicted MIPD outcomes, supporting better patient selection and alignment of complexity with surgical expertise.