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Abstract

We would like to thank Zhang et al1Zhang D. Li J. Li Z. et al.Research design can be improved to support double-guidewire technique.Gastrointest Endosc. 2019; 89: 654Scopus (1) Google Scholar for their interest in and comments on our study.2Eminler A.T. Parlak E. Koksal A.S. et al.Wire-guided cannulation over a pancreatic stent method increases the need for needle-knife precutting in patients with difficult biliary cannulation.Gastrointest Endosc. 2019; 89: 301-308Abstract Full Text Full Text PDF PubMed Scopus (15) Google Scholar Randomization based on a single sequence of random assignments is defined as a simple randomization. This technique maintains complete randomness of the assignment of a subject to a particular group. It is simple and easy to implement in clinical research. Simple randomization works well for large trials (n >100) and small to moderate clinical trials (n <100) without covariates.3KP Suresh An overview of randomization techniques: an unbiased assessment of outcome in clinical research.J Hum Reprod Sci. 2011; 4: 8-11Crossref PubMed Scopus (627) Google Scholar In our study, we simply aimed to compare the 2 most common methods that have been used to improve the success rate of biliary cannulation, without any covariates; therefore, we prefered to use the simple randomization method. Second, it is well known that endoscopists face a dilemma when making a choice about the cannulation technique if the guidewire inadvertently enters the pancreatic duct during attempts at biliary cannulation. In this study, we compared only the 2 most common methods: double-guidewire technique and wire-guided cannulation over a pancreatic stent. Transpancreatic precut sphincterotomy (TPS) is another technique that can be performed in such a case. We agree with Zhang et al1Zhang D. Li J. Li Z. et al.Research design can be improved to support double-guidewire technique.Gastrointest Endosc. 2019; 89: 654Scopus (1) Google Scholar that needle-knife precutting (NKP) is a somewhat high-risk procedure, as we mentioned in our study. However, the incidence of adverse events after TPS ranges from 3.5% to 20.5% (median, 13.1%) and the European Society of Gastrointestinal Endoscopy recommends this technique to be performed by only experts.4Testoni P.A. Mariani A. Aabakken L. et al.Papillary cannulation and sphincterotomy techniques at ERCP: European Society of Gastrointestinal Endoscopy (ESGE) clinical guideline.Endoscopy. 2016; 48: 657-683Crossref PubMed Scopus (277) Google Scholar Recently, we observed 2 patients who experienced perforation or dissection after TPS, and we hypothesized that the septum seperating the common bile duct and pancreatic duct was overablated by transpancreatic septotomy, and as a result of loss of tissue integrity, the guidewire was passed through the soft tissue or the common bile duct, causing perforation or dissection.5Eminler AT, Koksal AS, Parlak E. Modified transprepancreatic septotomy reduces postoperative complications: Is it always innocent? Available at: https://journals.lww.com/md-journal/Blog/MedicineCorrespondenceBlog/pages/post.aspx?PostID=82. Accessed June 1, 2018.Google Scholar There are not enough data to guide endoscopists to make a choice between TPS and NKP. However, the anatomy of the papilla (eg, small, protuberant) and the experience of the endoscopist with the technique may play a role.4Testoni P.A. Mariani A. Aabakken L. et al.Papillary cannulation and sphincterotomy techniques at ERCP: European Society of Gastrointestinal Endoscopy (ESGE) clinical guideline.Endoscopy. 2016; 48: 657-683Crossref PubMed Scopus (277) Google Scholar Finally, we mentioned the increased risk of adverse events (especially post-ERCP pancreatitis) with the double-guidewire technique, and we think that one of the most important factors determining the development of post-ERCP pancreatitis is the succesful replacement of a pancreatic stent. We agree with Zhang et al1Zhang D. Li J. Li Z. et al.Research design can be improved to support double-guidewire technique.Gastrointest Endosc. 2019; 89: 654Scopus (1) Google Scholar that endoscopists should consider a stepwise algorithm in patients with unintentional passage of the guidewire into the main pancreatic duct. Further prospective randomized studies, including all of the above-mentioned techniques (double-guidewire, wire-guided cannulation over a pancreatic stent, NKP, TPS), and taking into consideration the anatomy of the papilla and experience of the endoscopists, are needed to clarify the issue. Research design can be improved to support double-guidewire techniqueGastrointestinal EndoscopyVol. 89Issue 3PreviewWe have read with great interest the article by Eminler et al1 concerning how the method of wire-guided cannulation over a pancreatic stent (WGC-PS) increases the need for needle-knife precutting (NKP) in comparison with the double-guidewire technique (DGW) in patients with difficult biliary cannulation. This is an interesting prospective randomized study; however, we believe that the research design can still be improved. Full-Text PDF