Risk scoring system and predictor for clinically relevant pancreatic fistula after pancreaticoduodenectomy.

Abstract

To establish a scoring system to predict clinically relevant postoperative pancreatic fistula (CR-POPF) after pancreaticoduodenectomy (PD). The clinical records of 921 consecutive patients who underwent PD between 2008 and 2013 were reviewed retrospectively. Postoperative pancreatic fistula (POPF) was defined and classified by the international study group of pancreatic fistula (ISGPF). We used a logistic regression model to determine the independent risk factors of CR-POPF and developed a scoring system based on the regression coefficient of the logistic regression model. The optimal cut-off value to divide the risk strata was determined by the Youden index. The patients were divided into two groups (low risk and high risk). The independent sample t test was used to detect differences in the means of drain amylase on postoperative day (POD) 1, 2 and 3. The optimal cut-off level of the drain amylase to distinguish CR-POPF from non-clinical POPF in the two risk strata groups was determined using the receiver operating characteristic (ROC) curves. Grade A POPF occurred in 106 (11.5%) patients, grade B occurred in 57 (6.2%) patients, and grade C occurred in 32 (3.5%) patients. A predictive scoring system for CR-POPF (0-6 points) was constructed using the following four factors: 1 point for each body mass index ≥ 28 [odds ratio (OR) = 3.86; 95% confidence interval (CI): 1.92-7.75, P = 0.00], soft gland texture (OR = 4.50; 95%CI, 2.53-7.98, P = 0.00), and the difference between the blood loss and transfusion in operation ≥ 800 mL (OR = 3.45; 95%CI, 1.92-7.75, P = 0.00); and from 0 points for a 5 mm or greater duct diameter to 3 points for a less than 2 mm duct (OR = 8.97; 95%CI: 3.70-21.77, P = 0.00). The ROC curve showed that the area under the curve of this score was 0.812. A score of 3 points was suggested to be the best cut-off value (Youden index = 0.485). In the low risk group, a drain amylase level ≥ 3600 U/L on POD3 could distinguish CR-POPF from non-clinical POPF (the sensitivity and specificity were 75% and 85%, respectively). In the high risk group, the best cut-off was a drain amylase level of 1600 (the sensitivity and specificity were 77 and 63%, respectively). A 6-point scoring system accurately predicted the occurrence of CR-POPF. In addition, a drain amylase level on POD3 might be a predictor of this complication.