A multi-institutional external validation of the fistula risk score for pancreatoduodenectomy

Abstract

Background: The Fistula Risk Score (FRS), a ten-point scale that relies on weighted influence of four variables, has been shown to effectively predict clinically relevant postoperative pancreatic fistula (CR-POPF) development and its consequences after pancreatoduodenectomy (PD). The proposed FRS demonstrated excellent predictive capacity; however, external validation of this tool would confirm its universal applicability.

Methods: From 2001 to 2012, 594 PDs with pancreatojejunostomy reconstructions were performed at three institutions. POPFs were graded by International Study Group on Pancreatic Fistula standards as grades A, B, or C. The FRS was calculated for each patient, and clinical outcomes were evaluated across four discrete risk zones as described in the original work. Receiver operator curve analysis was performed to judge model validity.

Results: One hundred forty-two patients developed any sort of POPF, of which 68 were CR-POPF (11.4 % overall; 8.9 % grade B, 2.5 % grade C). Increasing FRS scores (0-10) correlated well with CR-POPF development (p < 0.001) with a C-statistic of 0.716. When segregated by discrete FRS-risk groups, CR-POPFs occurred in low-, moderate-, and high-risk patients, 6.6, 12.9, and 28.6 % of the time, respectively (p < 0.001). Clinical outcomes including complications, length of stay, and readmission rates also increased across risk groups.

Conclusion: This multi-institutional experience confirms the Fistula Risk Score as a valid tool for predicting the development of CR-POPF after PD. Patients devoid of any risk factors did not develop a CR-POPF, and the rate of CR-POPF approximately doubles with each subsequent risk zone. The FRS is validated as a strongly predictive tool, with widespread applicability, which can be readily incorporated into common clinical practice and research analysis.