Development and validation of risk prediction nomogram for pancreatic fistula and risk-stratified strategy for drainage management after pancreaticoduodenectomy.

Abstract

Postoperative pancreatic fistula (POPF) is the major complication following pancreaticoduodenectomy (PD). We sought to develop and validate a risk prediction model for POPF after PD with the aim of determining personal risk probability and proposing a novel strategy for intraoperative placement and/or early-removal of prophylactic drainage. Data from 993 patients undergoing PD from January 2012 to December 2016 were retrospectively analyzed. Patients were randomly assigned to either training cohort or validation cohort. A nomogram was formulated based on the results from multivariable regression model for prediction of POPF. Internal and external validation were carried out with calibration plot respectively. POPF occurred in 162 (16.3%) patients. The final pre-/intra-operative prediction model included alanine transaminase level [odds ratio (OR) 1.00, 95% confidence interval (CI): 1.00-1.00, P=0.023], combined portal-superior mesenteric vein resection (OR 0.22, 95% CI: 0.05-0.95, P=0.043), pancreatic duct diameter (OR 1.48, 95% CI: 1.11-1.96, P=0.007), intraoperative colloid infusion (OR 1.00, 95% CI: 1.00-1.00, P=0.001), pathology (OR 1.71, 95% CI: 1.09-2.66, P=0.018). The area under the curve (AUC) was 0.667 in the training cohort and 0.621 in the validation cohort. The final postoperative prediction model included pancreatic duct diameter (OR 1.58, 95% CI: 1.14-2.19, P=0.006), intraoperative colloid infusion (OR 2.52, 95% CI: 1.26-5.06, P=0.009), drainage fluid amylase on postoperative day 3 (POD3) (OR 4.70, 95% CI: 3.30-6.70, P<0.001), and neutrophil count on POD3 (OR 2.83, 95% CI: 1.63-4.93, P<0.001). The AUC was 0.809 in the training cohort and 0.797 in the validation cohort. Based on these variables, two nomogram prediction models were developed respectively. The calibration plot of the two models showed a good correlation between the expected risk and the actual risk in the low-risk range. Our risk-stratified strategy for drain management according to nomograms may be beneficial for 34.5% of patients. Our study formulated and validated two nomogram models for predicting POPF that performed particularly well in the low-risk range. This tool may allow surgeons to propose a risk stratified strategy for intraoperative drain placement and early drain removal, which may be beneficial for a substantial proportion of patients.