Possible reasons for the regrettable results of patency of an inside stent in endoscopic transpapillary biliary stenting

Abstract

Endoscopic biliary decompression is a minimally invasive procedure for cholestasis since the first endoscopic retrograde cholangiopancreatography-guided biliary stenting performed by Soehendra and Reynders-Frederix. Among the endoscopic biliary decompression, endoscopic transpapillary biliary stenting (EBS), is a mainstream choice and presently has two methods of placement: stenting above the sphincter of Oddi (SO) (suprapapillary) and stenting across the SO (transpapillary). Stent patency is the most important concern for patients, endoscopists and physicians because it can affect both the life prognosis and treatment schedule of patients. Biliary stent occlusion can occur because of several factors. Among them, direct food impaction, biofilm formation, and sludge formation play important roles and are presumed to be theoretically overcome by EBS above the SO. Thus, EBS above the SO is expected to result in a longer patency than EBS across the SO.In the literature, there have been six comparative studies on EBS for distal biliary obstruction in which the stent was placed above or across the SO, including two randomized controlled trials (RCTs) with negative results of stenting above the SO. With respect to EBS for hilar biliary obstruction, there have been no RCTs, whereas four retrospective comparative studies with negative results and four retrospective comparative studies showing positive results of stenting above the SO have been reported. In this review, we focused on EBS above and across the SO, and summarized the positive and negative results of the two types of stenting to promote effective clinical practice and to provide a basis for future studies.

A Prospective Multicenter Study of “Inside Stents” for Biliary Stricture: Multicenter Evolving Inside Stent Registry (MEISteR)

“…Although stent placement across the papilla has been the standard of care, the concept of metal and plastic stents above the papilla has been investigated both in malignant and benign biliary strictures [9]. However, most studies were retrospective with a small sample size, and no RCTs have proven the superiority of stents above the stricture to stents across the papilla thus far.…”

“…Clinical trials of anti-reflux biliary stents have been conducted, but their role is still controversial [8]. Stents above the papilla, so-called "inside stents," have been investigated using both metal and plastic stents [9]. Fully-covered self-expandable metal stents (FCSEMS) with a retrieval lasso are increasingly utilized for benign biliary strictures at the hilum or anastomotic strictures [10][11][12][13], but FCSEMS is not always indicated in patients with nondilated ducts.…”

Endoscopic management of perihilar cholangiocarcinoma

“…A recent randomized controlled trial 86 has also reported that efficacy of bilateral SIS and SBS deployment may be similar in terms of total adverse events, technical and clinical success, stent patency, and survival (the stent patency rates at 3 and 6 months was higher in the SIS group without statistical difference). Furthermore, it has been recommended that SEMS (via SBS deployment) should be placed above the papilla to avoid pancreatitis and methods involving stent placement across the papilla should be avoided 87,88 . Exchangeable IS and slim‐covered SEMS (6 mm in diameter) have been used for not only preoperative drainage but also unresectable PHCC 89–92 .…”

“…Furthermore, it has been recommended that SEMS (via SBS deployment) should be placed above the papilla to avoid pancreatitis and methods involving stent placement across the papilla should be avoided. 87,88 Exchangeable IS and slim-covered SEMS (6 mm in diameter) have been used for not only preoperative drainage but also unresectable PHCC. [89][90][91][92] Furthermore, EUS-guided biliary drainage (EUS-BD) has recently been reported for unresectable PHCC [93][94][95] with a technical success rate of over 90% and a clinical success rate of over 70%.…”

Efficacy Analysis of Suprapapillary versus Transpapillary Self-Expandable Metal Stents According to the Level of Obstruction in Malignant Extrahepatic Biliary Obstruction

“…A previous study has shown that placement of the stent above the intact sphincter of Oddi is associated with longer stent patency and lower occlusion rate. 4 In hilar MBO, stent patency is affected by various factors such as insertion method (side-by-side, stent-in-stent) and how much intrahepatic bile duct drainage has been performed. Thus, there is a limit to the interpretation of the role of stent position with AOV.…”