External Validation of the ISGPS Complexity Grading System for Minimally Invasive Pancreatoduodenectomy: Insights from the IGOMIPS registry

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.