ORIGINAL ARTICLE Endoscopic stenting in bile duct cancer increases liver volume Chang Hun Lee, MD, 1,3 Seong Hun Kim, MD, PhD, 1,3 In Hee Kim, MD, PhD, 1,3 Sang Wook Kim, MD, PhD, 1,3 Soo Teik Lee, MD, PhD, 1,3 Dae Ghon Kim, MD, PhD, 1,3 Jae Do Yang, MD, 2,3 Hee Chul Yu, 2,3 Baik Hwan Cho, MD, PhD, 2,3 Seung Ok Lee, MD, PhD 1,3 Jeonju, South Korea Background: Objective evaluation tools for assessing the effectiveness of stenting in palliative treatment of malig- nant biliary obstruction are not satisfactory. Effects of biliary stenting on liver volume change have never been studied. Objective: We aimed to use volumetry to analyze liver volume changes after endoscopic stenting in bile duct cancer according to the location and number of stents. Design: Retrospective review. Setting: University hospital. Patients: Patients with a diagnosis of hilar or distal bile duct cancer and who underwent biliary metal stenting. Interventions: ERCP with self-expandable metal stent placement. Main Outcome Measurements: Liver volume change after biliary stenting and its comparison according to the location (hilar vs distal common bile duct) and number (hilar bilateral vs hilar unilateral). Results: There were 60 patients; 31 were treated for hilar bile duct cancer (13 for bilateral stent and 18 for uni- lateral stent) and 29 for distal bile duct cancer. Overall mean follow-up duration was 11.7  4.9 weeks. Liver vol- ume increased 17.4  24.1%. The rate of liver growth was rapid during the early period from 4 to 8 weeks. Stenting in hilar bile duct cancer tended to increase liver volume more than distal biliary stents (22.5% vs 11.9%, P Z .091). In hilar bile duct cancer, unilateral and bilateral stents showed similar liver volume increases (20.1% and 25.8%, respectively; P Z .512). Limitations: Single center, retrospective. Conclusions: Biliary stenting markedly increased liver volume in both hilar and distal bile duct cancer. Our data suggest that liver volume assessment could be a useful tool for evaluating stent efficacy. (Gastrointest Endosc 2014;-:1-9.) Bile duct cancers are one of the most common causes of biliary obstruction, and endoscopic biliary stenting is widely used to decompress obstructive lesions. 1,2 Most bile duct cancers do not cause any symptoms until they reach an advanced stage and are unresectable at the time of diagnosis. 3,4 Biliary stenting is an alternative to surgery for palliative treatment of patients with advanced bile duct cancer. The optimal stent type or number for biliary stenting is an unresolved issue, and the relative merits of unilateral and bilateral stenting for treating hilar biliary obstruction are still under debate. Unilateral stenting is technically easier and less expensive than bilateral stenting and, in most cases, covers more than 25% to 30% of the liver vol- ume, which is known as the minimum range, to relieve jaundice. However, in some instances, unilateral drainage Abbreviations: AST, aspartate aminotransferase; 3D, 3-dimensional; SEMS, self-expandable metal stent. DISCLOSURE: All authors disclosed no financial relationships relevant to this article. Copyright ª 2014 by the American Society for Gastrointestinal Endoscopy 0016-5107/$36.00 http://dx.doi.org/10.1016/j.gie.2014.01.051 Received August 30, 2013. Accepted January 27, 2014. Current affiliations: Division of Gastroenterology, Department of Internal Medicine (1), Department of Surgery, Chonbuk National University Medical School and Hospital (2), Biomedical Research Institute, Chonbuk National University Hospital (3), Jeonju, South Korea. Reprint requests: Seung Ok Lee, MD, PhD, Department of Internal Medicine, Chonbuk National University Medical School, San 2-20 Geumam-dong, Deokjin-gu, Jeonju, Jeonbuk 561-180, South Korea. www.giejournal.org Volume -, No. - : 2014 GASTROINTESTINAL ENDOSCOPY 1