Updated Alternative Fistula Risk Score (ua-FRS) to Include Minimally Invasive Pancreatoduodenectomy

Abstract
Minimally invasive pancreatoduodenectomy (MIPD) may be associated with an increased risk of postoperative pancreatic fistula. In this study, the alternative Fistula Risk Score (a-FRS) was validated in a pan-European cohort of 952 patients undergoing MIPD and performed well after minor adjustment, in both open and MIPD. 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. MIPD may be associated with an increased risk of postoperative 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. 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. 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. 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.