Updated Alternative Fistula Risk Score (ua-FRS) to Include Minimally Invasive Pancreatoduodenectomy: Pan-European Validation

Objective: The aim of the study was to validate and optimize the alternative Fistula Risk Score (a-FRS) for patients undergoing minimally invasive pancreatoduodenectomy (MIPD) in a large pan-European cohort. Background: MIPD may be associated with an increased risk of postopera-tive pancreatic fistula (POPF). The a-FRS could allow for risk-adjusted comparisons in research and improve preventive strategies for high-risk patients. The a-FRS, however, has not yet been validated specifically for laparoscopic, robot-assisted, and hybrid MIPD. Methods: A validation study was performed in a pan-European cohort of 952 consecutive patients undergoing MIPD (543 laparoscopic, 258 robot-assisted, 151 hybrid) in 26 centers from 7 countries between 2007 and 2017. The primary outcome was POPF (International Study Group on Pancreatic Surgery grade B/C). Model performance was assessed using the area under the receiver operating curve (AUC; discrimination) and calibration plots. Validation included univariable screening for clinical variables that could improve performance. Results: Overall, 202 of 952 patients (21%) developed POPF after MIPD. Before adjustment, the original a-FRS performed moderately (AUC 0.68) and calibration was inadequate with systematic underestimation of the POPF risk. Single-row pancreatojejunostomy (odds ratio 4.6, 95 confidence interval [CI] 2.8-7.6) and male sex (odds ratio 1.9, 95 CI 1.4-2.7) were identified as important risk factors for POPF in MIPD. The updated a-FRS, consisting of body mass index, pancreatic texture, duct size, and male sex, showed good discrimination (AUC 0.75, 95 CI 0.71-0.79) and adequate calibration. Performance was adequate for laparoscopic, robot-assisted, and hybrid MIPD and open pancreatoduodenectomy. Conclusions: The updated a-FRS (www.pancreascalculator.com) now includes male sex as a risk factor and is validated for both MIPD and open pancreatoduodenectomy. The increased risk of POPF in laparoscopic MIPD was associated with single-row pancreatojejunostomy, which should therefore be discouraged.