Bret T. Petersen, MD, FASGE

Associate Editor



Bret T. Petersen, MD, FASGE, is Professor of Medicine in the Division of Gastroenterology and Hepatology at the Mayo Clinic in Rochester, Minnesota. His practice is focused in the Mayo Pancreas Clinic and the Advanced Endoscopy Group. His professional interests include pancreatic and biliary diseases, performance and outcomes of ERCP, and delivery of endoscopic services. At Mayo, Dr. Petersen is a past Director of Endoscopy and has served on multiple clinic and foundation committees. He has directed numerous American Society for Gastrointestinal Endoscopy (ASGE) and Mayo courses, particularly related to the performance of ERCP. He has received the Mayo Award for Excellence, GI Fellows Award for Outstanding Teacher, and Department of Medicine Laureate Award (GI), as well as the Master Endoscopist Award of the ASGE. Dr. Petersen is the incoming Secretary for (ASGE) and a past Chair of the Technology and Quality Assurance in Endoscopy committees.



Boston Scientific 

Advisory Board 

Ethicon/J & J



Stenting for Hilar Strictures – Stent-In-Stent and Side-By-Side Equivalent but Different

Bret T. Petersen, MD, FASGE reviewing Lee TH, et al. Gastrointest Endosc 2019 Mar 21.

Malignant biliary strictures at the hepatic hilum are relatively common lesions, for which endoscopic stenting is appropriate. When surgical resection for cure cannot be entertained and long-term palliation is desired, bilateral metal stents are commonly employed. Placement can be performed in semi-parallel side-by-side (SBS) alignment or in a stent-in stent (SIS) (or “Y”) alignment to the right and left lobes. In this prospective, multicenter study, 69 patients with confirmed, inoperable malignant hilar lesions were randomized to SIS (34) versus SBS (35) biliary drainage. The primary outcome of total adverse events did not differ between SIS and SBS treatment (23.5% vs 28.6%, respectively; p=0.633). Non-significant differences were noted for outcomes of primary technical success (SIS 100% vs SBS 91.4%; p=0.081), clinical success (SIS 94.1% vs SBS 90.6%; p=0.668), patency at 3 months (85.3% in the SIS group and 65.7% in the SBS group; p=0.059), patency at 6 months (SIS 47.1% and SBS 31.4%; p=0.184), median cumulative patency, and survival probability.

When malignant hilar obstruction develops, current practice strives to drain 50% or more of the liver to preserve sufficient hepatic function. Plastic stents are often employed if uncertainty exists regarding whether the accessible ducts will provide adequate drainage. When extensive lobar drainage can be accomplished and surgery is not planned, metal stents are preferable. While prior retrospective studies differ, this prospective study demonstrates virtual equivalence of the 2 conformations of stenting for hilar obstruction, with slightly better success and patency duration using the stent-within-stent approach. While parallel stents may occlude earlier, they also can be easier to palliate by re-stenting upon secondary occlusion. One challenge of either approach is that of pain from excessive stent calibers deployed in the extrahepatic ducts, perhaps favoring the stent-within-stent approach. Either approach appears acceptable, assuming appropriate skills and availability of correct stent calibers and lengths.
Note to readers:
At the time we reviewed this paper, its publisher noted that it was not in final form and that subsequent changes might be made.

Bret T. Petersen, MD, FASGE
Bio and Disclosures

Back to Journal Scan

Lee TH, Moon JH, Choi JH, et al. Prospective comparison of endoscopic bilateral stent-in-stent versus stent-by-stent deployment for inoperable advanced malignant hilar biliary stricture. Gastrointest Endosc 2019 Mar 21. (Epub ahead of print) (