Endoscopy 2021; 53(10): 1020-1022
DOI: 10.1055/a-1446-9437

Transpancreatic biliary sphincterotomy for difficult biliary cannulation: can it be better than other methods?

Referring to Kylänpää L et al. p. 1011–1019
Hsiu-Po Wang
Division of Gastroenterology and Hepatology, Department of Internal Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
› Author Affiliations

Selective biliary cannulation is the critical step when endoscopic retrograde cholangiopancreatography (ERCP) is used to manage pancreaticobiliary diseases. However, difficult cannulation and failure of initial biliary cannulation can occur in 10 %–20 % of patients with a native major papilla [1]. Difficult biliary cannulation increases the risk of post-ERCP adverse events, such as post-ERCP pancreatitis (PEP), post-ERCP bleeding, and perforation.

“Transpancreatic biliary sphincterotomy, double-guidewire cannulation, and pre-cut sphincterotomy are all good choices, and the choice depends on each patient’s anatomy, such as patterns of biliary-pancreatic duct union or presence of diverticulum, as well as the endoscopist’s preference and experience.”

Several techniques have been developed to overcome difficult cannulation, including transpancreatic biliary sphincterotomy (TPBS), double-guidewire cannulation (DGC), and precut sphincterotomy, such as needle-knife papillotomy, or needle-knife fistulotomy (NKF). In TPBS, a sphincterotome is applied to dissect the septum between bile and pancreatic ducts after incidental cannulation of the pancreatic duct. Compared with needle-knife techniques, TPBS is less technically demanding because the depth of cutting is easier to control. In DGC, a guidewire is placed when pancreatic duct cannulation is achieved, to assist biliary cannulation with another guidewire. Both TPBS and DGC are easier to perform compared with the free-hand technique in precut sphincterotomy and have been recommended by the European Society of Gastrointestinal Endoscopy (ESGE) for cases of difficult cannulation or when repeated unintentional pancreatic cannulation occurs [2].

In the current issue of Endoscopy, Kylänpää et al. present results from a prospective, multicenter, randomized study that compared the rates of successful biliary cannulation and adverse events between TPBS and DGC in cases of difficult biliary cannulation [3]. The study screened 1190 ERCPs, and 203 patients were randomized. All cases met the Scandinavian Association for Digestive Endoscopy criteria for difficult biliary cannulation and involved the guidewire entering the pancreatic duct. The successful biliary cannulation rate was significantly higher in the TPBS group (84.6 %) than in the DGC group (69.7 %). Furthermore, TPBS with or without NKF rescued 70 % of cases of DGC failure (Kylänpä et al., Fig. 4). There was no difference in PEP rate or severity of PEP between the two groups. This is the largest randomized controlled trial (RCT) comparing TPBS and DGC to date, and all patients met the same criteria for difficult biliary cannulation. Weaknesses include the fact that PEP prophylaxis with rectal nonsteroidal anti-inflammatory drugs was not used in all patients. Prophylactic pancreatic stents, which are suggested by ESGE guidelines for TPBS [2], were placed at the discretion of the endoscopist and were seldom used. Finally, only short-term follow-up was done in this study.

The efficacy of TPBS has been inconsistent in previous small studies. The retrospective study by Huang et al. showed a similar rate of successful cannulation in TPBS (90.8 %) and DGC (86.9 %; P = 0.09), with a lower complication rate in the DGC group [4]. The RCT by Angsuwatcharakon et al. demonstrated that DGC had a similar biliary access rate vs. TPBS (73.9 % vs. 80.9 %, respectively; P = 0.724), but a shorter procedure time [5]. In the RCT by Sugiyama et al., TPBS had a higher success rate than DGC (94.1 % vs. 58.8 %; P = 0.001), with no significant difference in the overall adverse event rates between the two groups [6].

TPBS appears to be a safe and good choice in difficult biliary cannulation based on the available studies. The biliary cannulation rate was high in the TPBS group in the Kylänpää et al. study. However, the high overall success rate in the TPBS group may be attributed to two factors. First, all of the procedures were performed by experienced endoscopists and the results may not be generalizable to daily practice. Second, in the TPBS group, 10 /104 patients (9.6 %) underwent additional needle-knife techniques, which are usually considered to require more skill and experience in order to achieve biliary access. When TPBS cases with the combination technique (needle-knife technique) were excluded, the success rate in pure TPBS was 75 %, which was not significantly superior to pure DGC (69.7 %).

To date, the technique of TPBS has not been standardized and in the study by Kylänpää et al., the endpoint of TPBS was to expose the CBD. I suggest trying biliary cannulation guided by the patterns of biliary-pancreatic duct union (BPDU) ([Fig. 1]) to improve the success rate after a full-cut TPBS. Type A pattern is with long BPDU; after full-cut TPBS, the bile duct and pancreatic duct are completely divided. Type B pattern is with short BPDU; after full-cut TPBS, the orifice of the bile duct will be noted over the surface of sphincter muscle of the post-sphincterotomy ampulla. Additional NKF is needed for type C (separated type), the bile duct of which is buried in the sphincter muscle after full-cut TPBS. In our retrospective study comparing TPBS and NKF, we performed full-cut TPBS, followed by biliary cannulation guided by BPDU pattern. The rate of successful cannulation was similar between the pure TPBS group and the NKF group (74.2 % vs. 83.0 %; P = 0.34). The successful cannulation rate for TPBS with additional NKF was up to 83.9 %. The adverse events rates were not significantly different [7].

Zoom Image
Fig. 1 Suggested patterns of bile duct locations after full-cut transpancreatic biliary sphincterotomy. Type A: long biliary-pancreatic duct union (BPDU); Type B: short BPDU; Type C: separated BPDU.

A systematic review by Kawakami et al. concluded that precut techniques showed comparable results in achieving biliary access compared with TPBS [8]. Moreover, the presence of a diverticulum may increase the risk of complications and interfere with endoscopists’ decisions. Overcoming difficult biliary cannulation is a complex issue. In addition to endoscopist experience, the appearance of the ampulla of Vater, such as small and flat, may influence the success rate of biliary cannulation and the risk of complications. Prospective comparative trials with adequate statistical power are warranted to determine the best cannulation methods in different ampulla of Vater anatomy.

“Every road leads to Rome.” In my opinion, TPBS, DGC, and pre-cut sphincterotomy are all good choices. The choice of rescue procedure in patients with difficult cannulation depends on each patient’s anatomy, such as the pattern of biliary-pancreatic duct union or presence of diverticulum, as well as the endoscopist’s preference and experience.

Publication History

Publication Date:
15 July 2021 (online)

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