Introduction : The definition of postoperative pancreatic fistula (POPF) by the international study group for pancreatic surgery (ISGPS) is based on the drain fluid amylase (DFA) level. However, for this definition, the drains need to be positioned around the pancreatic anastomosis or stump. The aim of this study is to evaluate the clinical relevance of drain position and DFA after distal pancreatectomy (DP).

Methods : A retrospective study was performed of 355 patients who received DP at Seoul National University Bundang Hospital, between June, 2004 and December, 2018. Patients with no measured DFA or postoperative CT were excluded from the study. Demographic data and perioperative data including drain positions identified on CT and DFA were analyzed.

Results : Of 355 patients, 46 patients (13.0%) had clinically relevant POPF (CR-POPF), and 81 patients (22.9%) had a malpositioned drain. Patients with malpositioned drains developed more symptomatic fluid collections. (58.0% vs 43.1%, P=0.022) High BMI and longer operation time were risk factors of CR-POPF, while drain position was not. The rate of CR-POPF was significantly higher in the high DFA group, but even in the low DFA group, 9.1% of patients had CR-POPF.

Conclusions : The drain is malpositioned in about 1/5 of patients after DP. Drain malposition has a higher risk of symptomatic fluid collection, but does not lead to a higher risk of CR-POPF. The total POPF rate was 13.0%, and the POPF rate of patients with low DFA was 9.1%. These findings suggest that the ISGPS definition of POPF based on DFA levels is limited in DP.