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Abstract

We thank Dr Menon for his interest in our study1Mariani A. Giussani A. Di Leo M. et al.Guidewire biliary cannulation does not reduce post-ERCP pancreatitis compared with the contrast injection technique in low-risk and high-risk patients.Gastrointest Endosc. 2012; 75: 339-346Abstract Full Text Full Text PDF PubMed Scopus (63) Google Scholar in which we concluded that guidewire and contrast biliary cannulation of the common bile duct have similar effects on the incidence of post-ERCP pancreatitis (PEP) in low-risk and high-risk patients. The study was powered assuming an expected rate of PEP about twice as high in patients examined with contrast injection than in those undergoing guidewire cannulation. Before our study, the literature reported a protective effect of the guidewire over contrast injection against PEP. This was why we did not record the number of guidewire cannulations of the pancreatic duct (PD). Among the 5 published randomized controlled trials, only one trial2Lee T.H. Park do H. Park J.Y. et al.Can wire-guided cannulation prevent post-ERCP pancreatitis? A prospective randomized trial.Gastrointest Endosc. 2009; 69: 444-449Abstract Full Text Full Text PDF PubMed Scopus (118) Google Scholar reported the numbers of unintended PD cannulations in the guidewire (5 passes) and contrast (5 passes and 2 injections) arms. Taking 3 contrast injections into the PD as the cutoff usually considered to avoid further risk of PEP, do 3 guidewire cannulations of the PD constitute a similar risk factor ? If so, from a methodologic point of view, can it be proposed that only after 3 guidewire cannulations of the PD—as in the case of 3 contrast injections—one should already cross over to the other technique? How many patients would have to be excluded in a study with such firm methodologic criteria? Dr. Menon's comments should stimulate fresh studies to answer these questions. In answer to the second question, we confirm that our study was not powered to detect any difference in the method of biliary access between high-risk and low-risk subgroups. To overcome the problem of the subgroup analysis, we have now added, in logistic regression analysis, not only the method of cannulation and the risk class but also the interaction between these 2 variables. The only variable significantly associated with PEP was the risk class (odds ratio = 3.79; CI, 1.8-7.9; P < .001). Therefore, the effect of the method of cannulation on the incidence of PEP was not significantly different in the low-risk and high-risk patients who underwent ERCP. Guidewire cannulation and the risk of post-ERCP pancreatitisGastrointestinal EndoscopyVol. 76Issue 2PreviewMariani et al1 should be commended for an excellent study examining the risk of the contrast injection technique and the guidewire cannulation technique for post-ERCP pancreatitis (PEP). However, their conclusion that the risk of PEP is no different between the two techniques is too strong and therefore misleading. A major limitation of their method was the nonrecording of the number of guidewire cannulations of the pancreatic duct despite a similar control in the contrast injection arm (no more than 3 inadvertent pancreatic injections). Full-Text PDF