Prophylactic 5-Fr pancreatic duct stents are superior to 3-Fr stents: a randomized controlled trial

Abstract

Background: Temporary prophylactic pancreatic duct stenting effectively reduces post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) in high-risk patients, but the optimal stent remains unclear. We compared rate of spontaneous passage, and technical difficulty of placement for 3-Fr and 5-Fr stents.

Methods: A randomized controlled trial at a single academic medical center. Patients deemed high risk for PEP randomly received 5-Fr or 3-Fr pancreatic duct stents. Primary outcome was spontaneous stent passage by 2 weeks. Secondary outcomes were ease and time for stent placement, and number of guide wires required for the entire procedure.

Results: Patients (69 female [89 %]; mean age 44.9 years, standard deviation [SD] 16.8) were randomly assigned to receive 5-Fr (n = 38) and 3-Fr (n = 40) stents. Indications for stenting were similar. Seven patients in the 3-Fr group actually received a 5-Fr stent, and two in the 5-Fr group had a 3-Fr stent. Spontaneous passage or non-passage was confirmed in 64 (83 %). No statistically significant difference in spontaneous passage rates was seen (5-Fr group, 68.4 %; 3-Fr group 75.0 %; P = 0.617). Non-passage rates were 10.5 % (5-Fr group) and 10.0 % (3-Fr group) ( P = 1.00). The study was stopped after a futility analysis for the primary end point. Placement of 5-Fr stents was rated easier, at a mean score of 1.8 (5-Fr) vs. 3.4 (3-Fr), P < 0.001, with a trend towards being faster, 9.2 vs. 11.1 minutes ( P = 0.355). Fewer guide wires were required for 5-Fr stent placement, 1.5 vs. 1.9 ( P = 0.002). PEP rates did not differ ( P = 0.519).

Conclusion: Placement of 5-Fr compared to 3-Fr pancreatic duct stents for PEP prophylaxis is easier, faster, and requires fewer wires. No statistically significant difference in spontaneous passage was found between the two sizes.

Fig. 1

Patient flow chart represents all patients who consented to participate in the study. Numbers of patients excluded from the study, with reasons, are shown. A total of 156 were excluded. Among these four patients (2%) received a pancreatic duct stent for high-risk PEP prophylaxis but were not randomized at the request of the treating endoscopist.

Fig. 2

A pancreatic duct stent was successfully placed in 77 patients; 1 stent spontaneously fell out during the endoscopic retrograde cholangiopancreatography (ERCP) procedure. A total of 64 patients (82%) had spontaneous passage (n = 56) or non-passage (n = 8) documented within 2 weeks. Stent passage could not be classified in 13 patients (17%): 7 patients (5-Fr group, n = 5; 3-Fr group, n = 2) had abdominal X-rays taken > 18 days after placement, and 6 patients (5-Fr group, n = 3; 3-Fr group, n = 3) had endoscopic removal of the stent <10 days after placement. Stents were removed because of concern about stent occlusion in 5 patients (1 patient with mild post-ERCP pancreatitis). One pancreatic duct stent was exchanged during follow-up ERCP on day 2 after failed biliary cannulation on index ERCP.

Fig. 3

Time required for stent placement. a Requirement of greater than average amount of time (≥ 10 min) for stent placement occurred more frequently in the 3-Fr group compared with the 5-Fr group (P = 0.051). b Requirement of less than half the average amount of time for stent placement (≤ 5 min) occurred more frequently in the 5-Fr group compared with the 3-Fr group (P = 0.011). c Box plot of absolute time (minutes) required for all stent placements for 3-Fr and 5-Fr groups. Third quartile, median and first quartile data are represented numerically.