© Georg Thieme Verlag KG Stuttgart · New York
Pancreatic endoscopic retrograde cholangiopancreatography
11 January 2010 (online)
Short 5Fr versus long 3Fr pancreatic stents in patients at risk for post-endoscopic retrograde cholangiopancreatography pancreatitis (Chahal et al., Clin Gastroenterol Hepatol 2009 )
Some good studies as well as meta-analyses have demonstrated that prophylactic stent placement in patients at high risk for developing postendoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) decreases the risk of this complication    . What is uncertain, however, is whether short unflanged 5-Fr prostheses and 3-Fr long prostheses have comparable efficacy and spontaneous migration rates. A previous retrospective study from Indianapolis suggested that patients who had 3-Fr stents placed had decreased, albeit not statistically significant, rates of pancreatitis and higher rates of spontaneous stent migration precluding the need for additional endoscopic manipulation.
This prospective, unblinded, two-center study randomly placed 5-Fr/3-cm proximally unflanged pancreatic duct stents (n = 116) or 3-Fr/≥ 8-cm pancreatic duct stents (n = 133) in patients deemed to be at high risk for PEP. Outcome parameters included PEP and spontaneous stent migration at 24 hours, 7 days, and 14 days. After 14 days, spontaneous stent migration was noted in 88 % of patients with 3-Fr stents and in 98 % of patients with 5-Fr stents (P = 0.001). PEP occurred in 14 % of the 3-Fr and 9 % of the 5-Fr group, respectively (P = 0.3). There were no placement failures with 5-Fr stents whereas placement of 3-Fr stents was unsuccessful in 11 of the 133 patients (P = 0.0003). The authors concluded that 5-Fr stent placement is preferable in patients at high risk for PEP because of increased procedural success rates and higher rates of spontaneous passage.
Indications for stent placement were risk factors for pancreatitis, including major or minor papilla endoscopic sphincterotomy in approximately 50 % of the patients with suspected sphincter of Oddi dysfunction (SOD), biliary precut, balloon sphincteroplasty, papillectomy, difficult cannulation, and prior PEP. In our institution, only the papillectomy and those with a pancreatic duct leak in the setting of severe acute pancreatitis would receive 5-Fr stents, usually with barbs, as we routinely re-assess the papillectomy side for complete adenoma excision at 4 – 6 weeks and do not wish spontaneous stent extrusion in those patients with active duct disruption. We routinely use 0.021-inch Tracer Metro wire (Cook Inc., Winston-Salem, North Carolina, USA) with the result that unsuccessful placement of 3-Fr stents occurs in < 5 % of procedures and the need for multiple guide wires is uncommon (a risk factor for PEP in this study). This wire can be used to place manometry catheters, facilitate bile duct access, and undertake both endoscopic sphincterotomy and biliary stent placement. Moreover, only 6 % – 7 % of our patients require stent retrieval. We use 3-Fr stents because of a significantly lower incidence of both stent-related ductitis related to side branch occlusion and stent impaction at angulations within the pancreatic duct. The reason for discordance between our institutional results and the current study may simply be methodologic issues between a prospective and retrospective series in which patients with ansa loops and other variant anatomy were likely selected for placement of short stents. Nevertheless, ansa loops and acute ductal angulations do not preclude long stent placement in the vast majority of patients treated in our practice, and these loops can actually be straightened in most instances ([Fig. 1]).
Fig. 1 Ansa loop. a Ansa loop in a patient with hereditary pancreatitis. b Loop resolution followed by stricture dilation. c, d Multiple stent placement.