Endoscopic intervention has emerged to become the first line treatment for benign biliary strictures following liver transplantation. The current endoscopic approach involves repetitive dilatation of the stricture and placement of multiple large-diameter parallel plastic stents with frequent stent exchange to prevent biliary infection. Self-expandable metal stents (SEMSs) have been used for malignant biliary strictures, however SEMS placement for benign biliary conditions like post-transplantation have not been widely accepted due to tissue in-growth leading to long-term complications.
A research article to be published on July 28, 2010 in the World Journal of Gastroenterology described a preliminary experience with a prototype removable covered SEMS in two patients with refractory benign anastomotic biliary strictures.
The article described two patients who had similar clinical scenarios: recurrent biliary infection secondary to anastomotic biliary stricture, and failure of conventional placement of plastic stent in the common bile duct to alleviate biliary stricture. As a result, their liver function tests were persistently abnormal.
The prototype removable covered SEMS is a Niti-S biliary stent which consists of an implantable metal stent and a flexible introducer system (Taewoong Medical Co Ltd., Korea). The stent is a semi-rigid, flexible and expandable tubular device made of nitinol (nickel titanium alloy) wire. Upon deployment, the removable covered SEMS imparts an outward radial force on the luminal surface of the biliary duct to establish patency. There are two characteristic features of this prototype stent. Firstly, a 10 cm radio-opaque nylon string is incorporated into the distal end of the stent to facilitate endoscopic retrieval. Secondly, it has a waist which is 2 mm narrower than each end. The removal of RCSEMS was performed using a standard endoscopy biopsy forceps by grasping the string attached at the distal end of the RCSEMS and then pulling it via the working channel of the scope.
Following the placement of SEMS, the two patients had improved liver function. The stent remained in situ for 42 and 70 d and no stent migration was observed. Images of bile ducts post-SEMS removal demonstrated good patency with an improvement in diameter of more than 50% at the strictured area. Patients were followed up after the SEMS removal for 14 and 18 months respectively. During follow-up, liver function tests remained stable. No further episode of jaundice and infection and no further procedure was indicated.
This article described a new trend in managing benign biliary strictures. The authors believe that with this prototype stent, it could bring about a paradigm shift in the management of post-liver transplantation biliary strictures.
Reference: Tee HP, James MW, Kaffes AJ. Placement of removable metal biliary stent in post-orthotopic liver transplantation anastomotic stricture. World J Gastroenterol 2010; 16(28): 3597-3600
Correspondence to: Dr. Hoi-Poh Tee, MRCP, Gastroenterology Unit, Hospital Tengku Ampuan Afzan, Jalan Tanah Putih, 25100 Kuantan, Pahang, Malaysia. firstname.lastname@example.org
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World Journal of Gastroenterology (WJG), a leading international journal in gastroenterology and hepatology, has established a reputation for publishing first class research on esophageal cancer, gastric cancer, liver cancer, viral hepatitis, colorectal cancer, and H. pylori infection and provides a forum for both clinicians and scientists. WJG has been indexed and abstracted in Current Contents/Clinical Medicine, Science Citation Index Expanded (also known as SciSearch) and Journal Citation Reports/Science Edition, Index Medicus, MEDLINE and PubMed, Chemical Abstracts, EMBASE/Excerpta Medica, Abstracts Journals, Nature Clinical Practice Gastroenterology and Hepatology, CAB Abstracts and Global Health. ISI JCR 2009 IF: 2.092. WJG is a weekly journal published by WJG Press. The publication dates are the 7th, 14th, 21st, and 28th day of every month. WJG is supported by The National Natural Science Foundation of China, No. 30224801 and No. 30424812, and was founded with the name of China National Journal of New Gastroenterology on October 1, 1995, and renamed WJG on January 25, 1998.
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