[A single-center retrospective study of percutaneous drainage clinical characteristics of grade B and C postoperative pancreatic fistula and determination of the optimal intervention time].

Objective: To classified the fluid location of of grade B and C postoperative pancreatic fistula (POPF) and propose processing flow. Methods: Data from 232 patients who underwent pancreatic surgery from January 2018 to December 2022 at Department of General Surgery & Hepato-billo-pancreatic,Beijing Hospital were collected retrospectively. Forty-six patients who suffered from grade B and C POPF underwent ultrasound-guided drainage. There were 32 males and 14 females, with an age of (60.2±13.7)years (range:18 to 85 years). The imaging data of postoperative CT were collected and the the fluid location was classified. Then analyzed the drainage status when patents were diagnosed as POPF. Machine learning was performed and a random forest model was applied to construct the relationship between intervention time and mortality. The optimal intervention time was calculated. The patients were then divided into early and late intervention groups and clinical data and outcomes were compared using the t test,Mann-Whitney U test, χ ² test or Fisher's exact test between the two groups. Results: Based on the results of the random forest model, the optimal puncture time was within 5.38 days after the diagnosis of POPF. Based on the optimal time, 21 patients were subsumed into early intervention group and 25 patients were subsumed into late intervention group. The location of fluid collection was classified into four types: peripancreatic (32.7%,15/46), extra-pancreatic and epigastric (41.3%,19/46), extra-pancreatic and hypogastic (13.0%,6/46) and diffused (13.0%,6/46). The status of the drainage included normal in 10 patients (21.8%), displaced drain in 18 patients (39.1%) and drain removed or blocked in 18 patients (39.1%). The perioperative mortality rate was 19.0% (4/21) in the early intervention group and 8.0%(2/25) in the late. The late intervention group had significantly higher rates of positive drainage fluid cultures (88.0%(22/25) vs. 42.9%(10/21), χ ² =10.584, P =0.001), secondary surgery (24.0%(6/25) vs. 0(0/21), P =0.025), and readmission within 90 days(32.0%(8/25) vs. 4.8%(1/21), χ ² =5.381, P =0.020) than the early group, and a significantly longer postoperative hospital stay( M (IQR))(24(20)days vs. 39(53)days, Z =3.023, P =0.003). Conclusions: The location of the POPF fluid collection is classified into four types. Early radiological evaluation can detect abdominal effusion promptly,and early puncture and drainage will be beneficial in improving outcomes in these patents.