Sterile fluid collections in acute pancreatitis: catheter drainage versus simple aspiration.

PURPOSE: To compare the clinical outcome of needle aspiration versus percutaneous catheter drainage of sterile fluid collections in patients with acute pancreatitis.

METHODS: We reviewed the clinical and imaging data of patients with acute pancreatic fluid collections from 1998 to 2003. Referral for fluid sampling was based on elevated white blood cell count and fevers. Those patients with culture-negative drainages or needle aspirations were included in the study. Fifteen patients had aspiration of 10-20 ml fluid only (group A) and 22 patients had catheter placement for chronic evacuation of fluid (group C). We excluded patients with grossly purulent collections and chronic pseudocysts. We also recorded the number of sinograms and catheter changes and duration of catheter drainage. The CT severity index, Ranson scores, and maximum diameter of abdominal fluid collections were calculated for all patients at presentation. The total length of hospital stay (LOS), length of hospital stay after the drainage or aspiration procedure (LOS-P), and conversions to percutaneous and/or surgical drainage were recorded as well as survival.

RESULTS: The CT severity index and acute Ransom scores were not different between the two groups (p = 0.15 and p = 0.6, respectively). When 3 crossover patients from group A to group C were accounted for, the duration of hospitalization did not differ significantly, with a mean LOS and LOS-P of 33.8 days and 27.9 days in group A and 41.5 days and 27.6 days in group C, respectively (p = 0.57 and 0.98, respectively). The 60-day mortality was 2 of 15 (13%) in group A and 2 of 22 (9.1%) in group C. Kaplan-Meier survival curves for the two groups were not significantly different (p = 0.3). Surgical or percutaneous conversions occurred significantly more often in group A (7/15, 47%) than surgical conversions in group C (4/22, 18%) (p = 0.03). Patients undergoing catheter drainage required an average of 2.2 sinograms/tube changes and kept catheters in for an average of 52 days. Aspirates turned culture-positive in 13 of 22 patients (59%) who had chronic catheterization. In group A, 3 of the 7 patients converted to percutaneous or surgical drainage had infected fluid at the time of conversion (total positive culture rate in group A 3/15 or 20%).

CONCLUSIONS: There is no apparent clinical benefit for catheter drainage of sterile fluid collections arising in acute pancreatitis as the length of hospital stay and mortality were similar between patients undergoing aspiration versus catheter drainage. However, almost half of patients treated with simple aspiration will require surgical or percutaneous drainage at some point. Disadvantages of chronic catheter drainage include a greater than 50% rate of bacterial colonization and the need for multiple sinograms and tube changes over an average duration of about 2 months.