Bilateral vs unilateral placement of metal stents for inoperable high-grade malignant hilar biliary strictures

Post written by Tae Hoon Lee, MD, PhD, and Jong Ho Moon, MD, PhD, from the Department of Internal Medicine, Soonchunhyang University College of Medicine, Cheonan Hospital, and the Department of Internal Medicine, Soonchunhyang University College of Medicine, Bucheon Hospital, Bucheon, Republic of Korea.

There is no definite consensus on whether bilateral placement of metal stents is superior to single placement in patients with inoperable high-grade malignant hilar biliary stricture (MHS). Still endoscopic bilateral metal stenting is considered a technically difficult procedure in comparison with unilateral stenting and may increase the risk of complications in cases of technical failure. However, technical success rate is dramatically increasing with new metal stents and associated accessories with technical development. Therefore, we conducted this multicenter, prospective, randomized study to investigate the clinical outcomes of bilateral and unilateral placement of self-expandable metal stent (SEMS) in patients with inoperable high-grade MHS.


In advanced hilar strictures such as Bismuth type III or IV, stent patency was prolonged in the bilateral SEMS group. There was no difference in Bismuth type II between two groups.

The efficacy of bilateral or unilateral stenting for complex MHS remains controversial because of the lack of well-designed prospective comparative studies. This is the first prospective, randomized, multi-center study of bilateral and unilateral SEMS in patients with advanced high-grade MHS. Our results may provide a palliative endoscopic guidance to manage advanced MHS. The primary technical success rate was 95.5% (64/67) in the bilateral group and 100% (66/66) in the unilateral group (P = 0.244). Primarily bilateral drainage resulted in fewer re-interventions [42.6% (26/61)] in the bilateral group and 60.3% (38/63) in the unilateral group (P = 0.049). The median cumulative stent patency duration was 252 days in the bilateral group and 139 days in the unilateral group (log-rank test, P < 0.01). Also, in multivariate analyses, endoscopic bilateral drainage using an SEMS was more effective than unilateral drainage in terms of stent patency and survival in patients with advanced inoperable MHS.


Figure 3. Endoscopic bilateral and unilateral placement of self-expandable metal stent (SEMS). Bilateral stent-in-stent deployment (A): after deployment of the second stent through the deployed X-marked first stent, the bilateral metal stents were in a Y configuration. Bilateral side-by-side deployment (B): 2 stents were inserted in parallel into both intrahepatic ducts, and both were positioned above the level of the papilla, with their distal ends at the same level. Unilateral deployment (C): a single SEMS was inserted into the right intrahepatic duct side across the hilar stricture.

In our results, bilateral drainage using metallic stents was technically feasible and provided more prolonged stent patency duration by reducing the rate of re-intervention. For long-term palliation of advanced MHS, bilateral drainage using a metal stent may be recommended by expert endoscopists working in high-volume centers. Further studies with larger sample sizes are needed to confirm our results.

Read the full article online.

The information presented in Endoscopedia reflects the opinions of the authors and does not represent the position of the American Society for Gastrointestinal Endoscopy (ASGE). ASGE expressly disclaims any warranties or guarantees, expressed or implied, and is not liable for damages of any kind in connection with the material, information, or procedures set forth.

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