Performance of either biliary endoscopic sphincterotomy alone or dual biliary and pancreatic sphincterotomy similarly prevented approximately half of idiopathic recurrent acute pancreatitis cases in a trial in which 89 patients were randomized to treatments based on the presence or absence of sphincter of Oddi dysfunction.
The study is "the largest randomized clinical trial studying ERCP [endoscopic retrograde cholangiopancreatography] with SOM [sphincter of Oddi manometry] in this population" with long-term follow-up data, Dr. Gregory A. Coté of Indiana University in Indianapolis and his colleagues reported in the December issue of Gastroenterology (2012 [doi: 10.1053/j.gastro.2012.09.006]).
Source: American Gastroenterological Institute
Finding therapeutic equivalence between biliary endoscopic sphincterotomy (BES) and dual endoscopic sphincterotomy (DES) in preventing at least one episode of acute pancreatitis during follow-up is important, because the addition of pancreatic sphincterotomy to ERCP carries the risk of post-ERCP pancreatitis, bleeding, perforation, and sphincter restenosis, according to Dr. Coté and his associates.
To assess the therapeutic value of two types of sphincterotomy and the prognostic value of pancreatic SOD for patients with idiopathic recurrent acute pancreatitis (RAP), the researchers randomized 69 adults with SOD to BES or DES. The other 20 patients who did not have SOD were randomized to BES or a sham therapy. SOD was defined as basal pressure of 40 mm Hg or greater, "sustained for at least 30 seconds across two transducers," the researchers noted.
The patients were aged 18 years and older, and those with chronic pancreatitis or an identified cause of RAP were excluded from the study.
Of the 69 patients with SOD, RAP occurred in 49% of patients who underwent BES and 47% who underwent DES. There was no significant difference in rates of RAP between non-SOD patients who had BES and those who had a sham procedure (27% vs. 11%, respectively).
The risk of RAP was approximately four times higher in patients with SOD than in those without SOD, they added.
"Most RAP events occurred within 30 months of randomization in all subgroups," the researchers said.
Overall, chronic pancreatitis developed in 17% of all patients over a median of 78 months, and there was no difference in the probability of developing chronic pancreatitis in patients with and without SOD.
The study was limited by several factors, including its small sample size for the non-SOD population and the impact of environmental and genetic risk factors on idiopathic RAP, the researchers noted.
The small sample of patients with normal SOM meant that the researchers could draw no conclusions about the benefit of BES in these patients, but the results "represent preliminary data for estimating the sample size of a future definitive trial of ERCP with empiric biliary sphincterotomy," they noted.
In addition, the findings suggest that SOD "may be a secondary marker of more significant inflammation related to previous acute pancreatitis," and that pancreatic sphincterotomy "cannot be recommended as a curative treatment of unexplained RAP alone," they wrote.
None of the study authors had any financial conflicts to disclose.
