Gastrointestinal Intervention

Similar documents
Percutaneous Metallic Stent Placement for Palliative Management of Malignant Biliary Hilar Obstruction

Double-Stent System with Long Duodenal Extension for Palliative Treatment of Malignant Extrahepatic Biliary Obstructions: A Prospective Study

Intraluminal Brachytherapy after Metallic Stent Placement in Primary Bile Duct Carcinoma 1

Bilateral stenting methods for hilar biliary obstructions

Percutaneous Biliary Drainage Using Open Cell Stents for Malignant Biliary Hilar Obstruction

ACUTE CHOLANGITIS AS a result of an occluded

Jennifer Hsieh 1, Amar Thosani 1, Matthew Grunwald 2, Satish Nagula 1, Juan Carlos Bucobo 1, Jonathan M. Buscaglia 1. Introduction

Clinical Performance of GORE VIABIL Biliary Endoprosthesis in the Treatment of Malignant Strictures

Endoscopic Management of Biliary Strictures. Sammy Ho, MD Director of Pancreaticobiliary Services and Endoscopic Ultrasound Montefiore Medical Center

Covered biliary stents with proximal bare stent extension for the palliation of malignant biliary disease: can we reduce tumour overgrowth rate?

EGIS BILIARY STENT. 1. Features & Benefits 2. Ordering information 3. References

Early Infectious Complications of Percutaneous Metallic Stent Insertion for Malignant Biliary Obstruction

Afferent Loop Syndrome: Treatment by Means of the Placement of Dual Stents

Maximize Control. Minimize Migration.

Fluoroscopically Guided Balloon Dilation for Benign Anastomotic Stricture in the Upper Gastrointestinal Tract

Стенты «Ella-cs» Уважаемые коллеги! Высылаем очередной выпуск «Issue of ELLA Abstracts»

Endoscopic stenting in bile duct cancer increases liver volume

Manuel José Antunes Liberato * and Jorge Manuel Tavares Canena

Air cholangiography in endoscopic bilateral stent-in-stent placement of metallic stents for malignant hilar biliary obstruction

Lobar and segmental liver atrophy associated with hilar cholangiocarcinoma and the impact of hilar biliary anatomical variants: a pictorial essay

Biliary Metal Stents MAKING A DIFFERENCE TO HEALTH

STRICTURES OF THE BILE DUCTS Session No.: 5. Andrea Tringali Digestive Endoscopy Unit Catholic University Rome - Italy

Expandable stents in digestive pathology present use in an emergency hospital

Percutaneous biliary drainage: complications and efficiency at short and mean terms: about 50 cases

Hilar cholangiocarcinoma. Frank Wessels, Maarten van Leeuwen, UMCU utrecht

Original article: new surgical approaches to the Klatskin tumour

Cholangiocarcinoma (Bile Duct Cancer)

To evaluate 792 patients with malignant biliary obstruction after inner-stents drainage procedure

Approach to the Biliary Stricture

CURRICULUM VITAE

Percutaneous Metallic Stents in Patients with Obstructive Jaundice due to Hepatocellular Carcinoma

Dual Catheter Placement Technique for Treatment of Biliary Anastomotic Strictures After Liver Transplantation

Usefulness of a Guiding Sheath for Fluoroscopic Colorectal Stent Placement

Endoscopic Stent Placement in the Palliation of Malignant Biliary Obstruction

Current status of hepatic surgery in Korea

Primary patency of percutaneously inserted self-expanding metallic stents in patients with malignant biliary obstructionhpb_

Palliative Treatment of Malignant Esophagopulmonary Fistulas With Covered Expandable Metallic Stents

Endoscopic Management of the Iatrogenic CBD Injury

pitfall Table 1 4 disorientation pitfall pitfall Table 1 Tel:

The first stents designed for use in the biliary tree and

Interventional Endoscopy in PB Malignancy

Original Article Intervention

Portal vein stent placement for the treatment of postoperative portal vein stenosis: long-term success and factor associated with stent failure

Current Treatment Strategies for Hilar and Intrahepatic Cholangiocarcinoma

Biliary Anatomy in Living-related Liver Transplantation

Intraductal papillary mucinous neoplasm of the bile ducts: a rare form of premalignant lesion of invasive cholangiocarcinoma

of bile leakage after liver resecti

Bronchobiliary fistula treated with histoacryl embolization under bronchoscopic guidance: A case report

Optimal Bile Duct Division Using Real- Time Indocyanine Green Near-Infrared Fluorescence Cholangiography During Laparoscopic Donor Hepatectomy

Percutaneous Transhepatic Stent Placement in the Management of Portal Venous Stenosis After Curative Surgery for Pancreatic and Biliary Neoplasms

Management of Cholangiocarcinoma. Roseanna Lee, MD PGY-5 Kings County Hospital

Stent Collapse as a Delayed Complication of Placement of a Covered Gastroduodenal Stent

Paola Figueroa-Barojas, Mihir R. Bakhru, Nagy A. Habib, Kristi Ellen, Jennifer Millman, Armeen Jamal-Kabani, Monica Gaidhane, and Michel Kahaleh

Partially Covered Metal Stents May Not Prolong Stent Patency Compared to Uncovered Stents in Unresectable Malignant Distal Biliary Obstruction

The management of malignant tumours involving the main

Endoscopic Deployment of Multiple JOSTENT SelfX Is Effective and Safe in Treatment of Malignant Hilar Biliary Strictures

담낭절제술후발생한미리찌증후군의내시경적치료 1 예

Individual Pulmonary Vein Atresia in Adults: Report of Two Cases

Interventional Radiology Rounds:

Tumor Overgrowth After Expandable Metallic Stent Placement: Experience in 583 Patients With Malignant Gastroduodenal Obstruction

Percutaneous biliary drainage catheter insertion in patients with extensive hepatic metastatic tumor burden

Radiotherapy Prolongs Biliary Metal Stent Patency in Malignant Pancreatobiliary Obstructions

Self Expandable Metallic Stents in Malignant Biliary Obstruction: Safety and Efficacy

Treatment outcomes and prognostic factors of gallbladder cancer patients after postoperative radiation therapy

Jung-Hoon Park 1 Ho-Young Song 1 Jin Hyoung Kim 1 Deok Ho Nam 2 Jae-Ik Bae 3 Min-Hee Ryu 4 Hwoon-Yong Jung 4

Post-operative complications following hepatobiliary surgery: imaging findings and current radiological treatment options

Percutaneous transhepatic and endoscopic biliary drainage for malignant biliary tract obstruction: a meta-analysis

Newly Designed Sheaths for Gastroduodenal Intervention: An Experimental Study in a Phantom and Dogs

ROLE OF RADIOLOGY IN INVESTIGATION OF JAUNDICE

LIVER SURGERY 2. Case 1. Med 5 Refresher Course (Surgery) 2013/14. Dr Sunny Cheung

Management of Extensive Portal Vein Thrombosis

Management of the Mucin Filled Bile Duct. A Complication of Intraductal Papillary Mucinous Tumor of the Pancreas

Evaluation and Management of Refractory Biliary Stricture. J. David Horwhat, MD, FACG Director of Endoscopy Lancaster Gastroenterology, Inc.

Personal Profile. Name: 劉 XX Gender: Female Age: 53-y/o Past history. Hepatitis B carrier

Laparoscopic left hepatectomy in patients with intrahepatic duct stones and recurrent pyogenic cholangitis

Enteral stenting for gastric outlet obstruction and afferent limb syndrome following pancreaticoduodenectomy

MAKING CONNECTIONS. Los Angeles Medical Center

Is a Metallic Stent Useful for Non Resectable Esophageal Cancer?

Obstructive Jaundice Caused by Tuberculous Lymphadenopathies

Case Report pissn J Korean Soc Radiol 2012;67(4): INTRODUCTION CASE REPORT

7/11/2017. We re gonna help a lot of people today. Biliary/Pancreatic Endoscopy. AGS July 1-2, Kenneth M. Sigman, MD

EGIS ESOPHAGEAL STENT. 1. Features & Benefits 2. Ordering information 3. References & Clinical case

Percutaneous Transhepatic Release of an Impacted Lithotripter Basket and Its Fractured Traction Wire Using a Goose-Neck Snare: a Case Report

Intrahepatic Sarcomatoid Cholangiocarcinoma with Portal Vein Thrombosis: A Case Report 1

Percutaneous Palliation of Pancreatic Head Cancer: Randomized Comparison of eptfe/fep Covered Versus Uncovered Nitinol Biliary Stents

Endovascular Stent Placement for Interposed Middle Hepatic Vein Graft Occlusion after Living-Donor Liver Transplantation Using Right- Lobe Graft

State of the Art Imaging for Hepatic Malignancy: My Assignment

WallFlex Biliary RX Fully Covered Stent System Prescriptive Information

Case Report Thoracic Imaging. Eun Kyung Khil, MD 1, Heon Lee, MD, PhD 1, Keun Her, MD 2 INTRODUCTION CASE REPORT

Vascular complications in percutaneous biliary interventions: A series of 111 procedures

Early Symptomatic Strictures after Gastric Surgery: Palliation with Balloon Dilation and Stent Placement

Surgical anatomy of the biliary tract

Imaging diagnosis of clonorchiasis

Placement of self-expanding metal stents is a safe and effective palliative

Balloon Sheaths for Gastrointestinal Guidance and Access: A Preliminary Phantom Study

BRTO: Updates to Techniques

Gum O Jung and Dong Eun Park. Department of Surgery, Wonkwang University Hospital, Wonkwang University School of Medicine, Iksan, Korea

The Egyptian Journal of Hospital Medicine (July 2018) Vol. 72 (9), Page

Ultrasonography in the Surgical Treatment

OBJECTIVE. The purpose of this article is to compare the clinical effectiveness and complications. the treatment of benign urethral strictures.

Transcription:

Gastrointest Interv 2016;5:47 51 Gastrointestinal Intervention journal homepage: www.gi-intervention.org Review rticle Interventional radiologic approach to hilar malignant biliary obstruction Dong Il Gwon* S T R C T iliary obstruction due to advanced hepatic hilar malignancy is difficult to treat, both surgically and non-surgically, using endoscopic or percutaneous drainage. Since only about 10% to 20% of patients are eligible for resection of hepatic hilar malignancies, most patients receive palliative rather than curative treatment. Percutaneous palliation of advanced hepatic hilar malignancies can be accomplished in a variety of ways. Percutaneous bilateral metallic stent placement may be a reasonable option in patients with hilar malignancies to preserve the functional volume of the liver during the course of chemotherapy and to prevent procedure-related cholangitis of a contaminated undrained lobe. Percutaneous bilateral stent-in-stent placement using wide-mesh or open-cell design stents is a feasible and effective method of achieving bilateral drainage. Moreover, unilateral covered or uncovered metallic stent placement in the lobe with patent portal vein is safe and effective method for palliative treatment in patients with contralateral portal vein occlusion caused by hilar malignancies, obviating the need for bilateral stent placement in these patients. Keywords: ile ducts, intrahepatic; Malignancy; Percutaneous; Stents Copyright 2016, Society of Gastrointestinal Intervention. ll rights reserved. Introduction iliary obstruction due to advanced hepatic hilar malignancy is difficult to treat, both surgically and non-surgically, using endoscopic or percutaneous drainage. Since only about 10% to 20% of patients are eligible for resection of hepatic hilar malignancies, 1,2 most patients receive palliative rather than curative treatment. percutaneous approach can be a reasonable option to treat malignant hilar obstruction and is often the most appropriate management. Previous studies reported that percutaneous approaches had a higher technical/clinical success rate and lower incidence of infective complications compared with endoscopic approaches. 3 5 Percutaneous palliation of advanced hepatic hilar malignancies can be accomplished in a variety of ways. 6 18 The author therefore reviews percutaneous techniques for the treatment of hilar malignant biliary obstruction. Unilateral vs ilateral iliary Stent Placement There have been conflicting opinions as to whether stent placement should be unilateral or bilateral. 6,7,19 24 Some investigators have preferred bilateral stenting not only because unilateral stenting alone may not completely relieve jaundice 22 and may induce acute cholangitis 7 but also because stent patency may be longer than unilateral stenting. 6 On the other hand, others have advocated unilateral drainage not only because the risk of complications is lower than multiple stent deployment 20 but also because adequate palliation can be achieved by the drainage of only 25% of the liver. 24 In a report by De Palma et al, 19 patients with bilateral drainage had a significantly lower rate of successful stent insertion and a significantly higher rate of early cholangitis than patients with unilateral drainage. However, these previous reports have usually focused on technical or clinical outcomes of unilateral or bilateral drainage in advanced hilar obstruction according to ismuth-corlette classification. lthough it is unclear whether drainage of both liver lobes in patients with ismuth type II or higher malignant hilar tumors is necessary, to preserve the functional volume of the liver during the course of chemotherapy and to prevent procedure-related cholangitis of a contaminated undrained lobe, 6,7,19 23 bilateral drainage may be a reasonable option. ilateral biliary drainage can be accomplished by the percutaneous placement of multiple stents. 6 18 Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, san Medical Center, Seoul, Korea Received May 26, 2015; Revised July 14, 2015; ccepted July 14, 2015 * Corresponding author. Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, san Medical Center, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 05505, Korea. E-mail address: radgwon@amc.seoul.kr (D.I. Gwon). pissn 2213-1795 eissn 2213-1809 http://dx.doi.org/10.18528/gii150004 This is an open-access article distributed under the terms of the Creative Commons ttribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

48 Gastrointestinal Intervention 2016 5(1), 47 51 Percutaneous ilateral iliary Stent Placement Palliative stent placement for advanced hilar malignancies is usually accomplished through two separate transhepatic punctures in a Y configuration, X configuration or single transhepatic puncture in a T configuration. 6 18 Two techniques have been developed for the percutaneous placement of bilateral metallic stents, sideby-side and stent-in-stent deployment techniques. The side-byside deployment technique results in the simultaneous insertion of two parallel metallic stents to drain the bile ducts of both hepatic lobes (Fig. 1). This parallel arrangement, however, may prevent full expansion of metallic stents at and below the hepatic confluence. 9 lthough adequate drainage may be achieved, expansion of the stents to less than their full diameter may result in stent elongation or partial collapse of one or both stents. Recently, bilateral drainage using the partial stent-in-stent deployment procedure has been reported. 9,10 13,15,17 In the stent-instent deployment technique, a second stent is placed through the mesh of the first stent to enter the common bile duct (Fig. 2). Using this technique, the entire length of the stricture can continuously expand within a single stent caliber, a result that cannot be achieved using the side-by-side stent deployment technique. Moreover, overlapping of the two stents can effectively prevent displacement of the stents. However, passing a second metallic stent through the mesh of the first stent can be technically difficult if the first stent has a tightly woven closed-cell-design. 25 To overcome the technical difficulties associated with the stentin-stent deployment technique using closed-cell-design stents, some investigators adopted two types of metallic stents, of widemesh and open-cell design stents, as first stents and determined that both types performed equally well in bilateral stent-in-stent deployment. 10 13,15,17 The wide-mesh-design stent has a wider central mesh portion, permitting easy passage of the delivery system for the second stent. In a report by Kim et al, 10 the creation of a true T configuration using wide-mesh first stent was preferable to other approaches as it offered a large luminal diameter throughout the mesh of the first stent and that overlapping two stents was effective in preventing their displacement. The cells of the open-celldesign stents are connected more easily than the tight weaving and interlocking of other closed-cell-design stents. 15,17 Thus, opencell-design stents can be dilated easily by ballooning and remain dilated, thus permitting easy passage of the second stent during bilateral stenting and its wide expansion. Moreover, open-celldesign stents could be easily navigated through the tortuous strictures due to their low profile delivery system and high flexibility. Despite a paucity of percutaneous studies, there were no significant between group differences in stent occlusion rate and stent patency period. 15,17 Moreover, there were no significant differences between the wide-mesh and open-cell design stent groups in technical success, complications, successful internal drainage, and patient survival. 17 To achieve bilateral drainage in patients with stent occlusion, reintervention was more easily performed in patients in whom stents had been inserted in a T than in a Y configuration. 17 Therefore, T-configured stent-in-stent deployment for bilateral drainage may be preferable in patients with malignant hilar biliary obstruction unless technical difficulties necessitate Y- configured stent-in-stent deployment. 17 In previous studies using percutaneous bilateral stenting, the technical success rate ranged from 93% to 100%, the overall complication rate ranged from 0% to 7.7%, the successful internal drainage rate ranged from 87.5% to 92%, the median stent pa- Fig. 1. Side-by-side deployment technique (Y confi gu ration) for bilateral drainage. () Note simultaneous insertion of two stent endoprostheses from intrahepatic bile duct of both hepatic lobes to common bile ducts. () Cholangiogram after deployment shows successful Y-configured stent placement using two close-cell-design stents. Note right-sided stent (black arrows) and left-sided stent (white arrows). C Fig. 2. Stent-in-stent deployment technique (T configuration) for bilateral drainage. () Cholangiogram shows a malignant hilar obstruction. () fter inserting the first transverse stent from right to left hepatic duct, the guide wire for second stenting was successfully inserted into common bile duct through the mesh of the first stent (arrow). (C) Cholangiogram shows successful deployment of the second stent from the left side into the common bile duct through the mesh of the first stent.

Dong Il Gwon / Percutaneous hilar stenting 49 tency time ranged from 170 to 275 days, and the median patient survival time ranged from 126 to 299 days (Table 1). 10,11,15,17 Multiple stent placement can be a reasonable option in the patients who are anicteric with a high-grade hilar stricture and cholangitic after bilateral stent placement (Fig. 3). Percutaneous Unilateral iliary Stent Placement The indications for percutaneous unilateral biliary stent placement are no/little functional liver parenchyma due to huge tumor and unilateral portal vein occlusion with/without subsequent hepatic lobar atrophy due to hilar or parenchymal tumor. In general, the most important factor in regulating the volume of bile flow is the rate of bile salt synthesis by hepatocytes, which is regulated by the return of bile salts to the liver through enterohepatic circulation. When the portal vein of one liver lobe is obstructed, portal vein obstruction interrupts the cycle of enterohepatic circulation in the obstructed lobe. 13 Previous investigators reported successfully treating bile leakage by performing selective portal vein embolization, which induces cessation of bile production. 26,27 Thus, the liver lobe with portal vein occlusion caused by advanced hilar malignancies ceases to produce bile and becomes nonfunctional and atrophied. Hepatic lobar atrophy is a frequent accompaniment of hilar cholangiocarcinoma and has been reported to occur in 20% to 30% of patients with that diagnosis. 28,29 Hepatic lobar atrophy usually occurs in the setting of combined biliary and portal vein occlusion, which is most frequently ipsilateral to the atrophic lobe. Moreover, previous studies have reported a significant correlation between hepatic lobar atrophy and ipsilateral portal vein occlusion and that unilateral portal vein occlusion in the at- Table 1 Studies Involving Percutaneous ilateral Stenting for Hilar Malignant iliary Obstruction Study Number of patients Company Type of stent Number of stent Technical success (%) Stent patency (day, median) Patient survival (day, median) Kim et al 10 (2004) 57 Taewoong Medical Kim stent & Niti-S 114 100 170.3 193.6 ae et al 11 (2008) 42 Taewoong Medical Kim stent & Niti-D 82 98 187 247 hn et al 15 (2012) 26 oston Scientific Sentinol 59 93 191.8 299 Gwon et al 17 (2013) 106 Cook, oston Scientific Zilver, Sentinol 212 100 319 192 Fig. 3. Multiple stent deployment due to anatomic variation. () fter inserting of two stents in a T configuration from left side to right anterior and common bile duct, a 5-F catheter (arrowheads) was successfully inserted from right posterior duct to common bile duct. () Cholangiogram shows successful deployment of the third stent (arrows) from right posterior duct to common bile duct through the mesh of the first stent. Fig. 4. Computed tomographic images obtained before percutaneous transhepatic biliary drainage () and two months after unilateral stent placement () in a 75-year-old man with cholangiocarcinoma and right portal vein occlusion show little diameter change of left intrahepatic bile duct after right-sided unilateral stent placement (arrow).

50 Gastrointestinal Intervention 2016 5(1), 47 51 rophied lobe was present in 87% to 100% of patients. 28,29 To date, there has been only one radiologic comparative study of unilateral and bilateral stenting in patients with hilar biliary obstruction with unilobar portal vein occlusion caused by advanced malignancies. 13 In a report by Gwon et al, 13 unilateral biliary metallic stent placement in the lobe with patent portal vein seemed to be a safe and effective palliative treatment of patients with contralateral portal vein occlusion caused by advanced hilar malignancy, obviating bilateral stent placement in these patients, because the hepatic lobe with portal vein occlusion caused by advanced hilar malignancies ceases to produce bile due to interruption of enterohepatic circulation. In the study, during the followup period, the intrahepatic bile ducts of the undrained lobe with portal vein occlusion in patients who underwent unilateral biliary stent placement showed a slight decrease in diameter on followup computed tomography, which means bile production in the undrained lobe may be functionally impaired or ceased by bile duct obstruction as well as portal vein occlusion (Fig. 4). Percutaneous Covered iliary Stent Placement The use of covered stents in the biliary system was initially developed to address the issue of tumor ingrowth. Recently, the use of polytetrafluoroethylene (PTFE)-covered stents has been found to be an effective treatment method, with the PTFE material serving as an effective barrier to prevent tumor ingrowth. 30 33 In * C Fig. 5. Unilateral covered stent placement in a 83-year-old man with intrahepatic cholangiocarcinoma and right portal vein occlusion. () Computed tomographic image shows intrahepatic bile duct dilatation and right portal vein occlusion (arrow) caused by intrahepatic cholangiocarcinoma (asterisk). () Cholangiogram via the left-sided catheter shows occlusion of the left intrahepatic bile duct and upper common bile duct. Right intrahepatic bile duct is not opacified by contrast media. (C) Cholangiogram 3 days after polytetrafluoroethylen-covered stent placement shows good passage of contrast media through the stent (arrows). Malignant hilar obstruction CT or MR ismuth type, PV occlusion PV occlusion (+) PV occlusion ( ) Unilobar PTD at lobe with patent PV Unilobar PTD at lobe with larger drainage Cholangitis (+) Cholangitis ( ) Cholangitis (+) Cholangitis ( ) Catheter advance or additional PTD Catheter advance or additional PTD Cholangitis ( ) Cholangitis ( ) Unilateral (covered) stenting ilateral (covered) stenting T stenting then YorXstenting Cholangitis ( ) Catheter removal Fig. 6. uthor s treatment algorithm of hilar malignant biliary obstruction. CT, computed tomography; MR, magnetic resonance; PV, portal vein; PTD, percutaneous transhepatic biliary drainage.

Dong Il Gwon / Percutaneous hilar stenting 51 one comparative study of PTFE-covered and uncovered stents, 34 PTFE-covered stents were significantly superior to uncovered stents in terms of stent patency. In general, one important limitation in using covered stent for treatment of malignant hilar biliary obstruction is a risk of occlusion of branching intrahepatic bile duct. Interestingly, in the previous studies, PTFE-covered stents for palliative treatment of malignant hilar biliary obstruction prevented tumor ingrowth without functional occlusion of the hepatic segmental bile ducts. 12,14 The branching intrahepatic bile ducts blocked by the covered stents showed a significant diameter decrease on the follow-up computed tomographic images and the serum bilirubin level also decreased significantly. In a report by Yi et al, 35 unilateral placement of PTFE-covered stents in the hepatic lobe with a patent portal vein was a safe and effective method for palliative treatment of patients with contralateral portal vein occlusion caused by advanced hilar malignancies (Fig. 5). lthough a covered stent could effectively prevent stent dysfunction caused by tumor ingrowth, covered stent dysfunction was mainly caused by sludge incrustation. Further investigations will be required in order to determine how to decrease the incidence of sludge formation. Conclusion In conclusion, percutaneous bilateral stenting may be a reasonable option in patients with hilar malignancies to preserve the functional volume of the liver during the course of chemotherapy and to prevent procedure-related cholangitis of a contaminated undrained lobe. Percutaneous bilateral stent-in-stent placement using wide-mesh or open-cell design stents is a feasible and effective method of achieving bilateral drainage in patients with malignant hilar biliary obstruction. Moreover, unilateral covered or uncovered metallic stent placement in the lobe with patent portal vein is safe and effective method for palliative treatment in patients with contralateral portal vein occlusion caused by advanced hilar malignancies, obviating the need for bilateral biliary stent placement in these patients. The author s percutaneous approach to treatment of patients with hilar malignant biliary obstruction was summarized in Fig. 6. Conflicts of Interest No potential conflict of interest relevant to this article was reported. References 1. ismuth H, Castaing D, Traynor O. Resection or palliation: priority of surgery in the treatment of hilar cancer. World J Surg. 1988;12:39-47. 2. Ogura Y, Mizumoto R, Tabata M, Matsuda S, Kusuda T. Surgical treatment of carcinoma of the hepatic duct confluence: analysis of 55 resected carcinomas. World J Surg. 1993;17:85-92; discussion 92-3. 3. Saluja SS, Gulati M, Garg PK, Pal H, Pal S, Sahni P, et al. Endoscopic or percutaneous biliary drainage for gallbladder cancer: a randomized trial and quality of life assessment. Clin Gastroenterol Hepatol. 2008;6:944-50. 4. Walter T, Ho CS, Horgan M, Warkentin, Gallinger S, Greig PD, et al. Endoscopic or percutaneous biliary drainage for Klatskin tumors? J Vasc Interv Radiol. 2013;24:113-21. 5. Paik WH, Park YS, Hwang JH, Lee SH, Yoon CJ, Kang SG, et al. Palliative treatment with self-expandable metallic stents in patients with advanced type III or IV hilar cholangiocarcinoma: a percutaneous versus endoscopic approach. Gastrointest Endosc. 2009;69:55-62. 6. Inal M, kgül E, ksungur E, Seydaoğlu G. Percutaneous placement of biliary metallic stents in patients with malignant hilar obstruction: unilobar versus bilobar drainage. J Vasc Interv Radiol. 2003;14:1409-16. 7. Cowling MG, dam N. Internal stenting in malignant biliary obstruction. World J Surg. 2001;25:355-9. 8. Laerge JM, Doherty M, Gordon RL, Ring EJ. Hilar malignancy: treatment with an expandable metallic transhepatic biliary stent. Radiology. 1990;177:793-7. 9. Kubota Y, Nakatani S, Nakahashi Y, Takaoka M, Kin H, Inoue K. ilateral internal biliary drainage of hilar cholangiocarcinoma with modified Gianturco Z stents inserted via a single percutaneous tract. J Vasc Interv Radiol. 1993;4:605-10. 10. Kim CW, Park W, Won JW, Kim S, Lee JW, Lee SH. T-configured dual stent placement in malignant biliary hilar duct obstructions with a newly designed stent. J Vasc Interv Radiol. 2004;15:713-7. 11. ae JI, Park W, Choi SJ, Kim HP, Lee SJ, Park YM, et al. Crisscross-configured dual stent placement for trisectoral drainage in patients with advanced biliary hilar malignancies. J Vasc Interv Radiol. 2008;19:1614-9. 12. Gwon DI, Ko GY, Yoon HK, Kim JH, Lee JM, Ohm JY, et al. Prospective evaluation of a newly designed T-configured stent graft system for palliative treatment of advanced hilar malignant biliary obstructions. J Vasc Interv Radiol. 2010;21:1410-8. 13. Gwon DI, Ko GY, Sung K, Yoon HK, Shin JH, Hyoung Kim J, et al. Percutaneous biliary metallic stent placement in patients with unilobar portal vein occlusion caused by advanced hilar malignancy: outcome of unilateral versus bilateral stenting. JR m J Roentgenol. 2011;197:795-801. 14. Gwon DI, Ko GY, Yoon HK, Kim YJ, Kim TH, Lee WH, et al. Safety and efficacy of percutaneous Y-configured covered stent placement for malignant hilar biliary obstruction: a prospective, pilot study. J Vasc Interv Radiol. 2012;23:528-34. 15. hn SJ, ae JI, Han TS, Won JH, Kim JD, Kwack KS, et al. Percutaneous biliary drainage using open cell stents for malignant biliary hilar obstruction. Korean J Radiol. 2012;13:795-802. 16. Kang C, Lee SW, Chung HH. newly designed Y-shaped covered stent in the palliative treatment of hepatic hilar malignant obstruction: case report. Korean J Radiol. 2013;14:97-101. 17. Gwon DI, Ko GY, Kim JH, Shin JH, Kim K, Yoon HK, et al. Percutaneous bilateral metallic stent placement using a stentin-stent deployment technique in patients with malignant hilar biliary obstruction. JR m J Roentgenol. 2013;200:909-14. 18. Li TF, Li Z, Han XW, Ren JZ, Jiao C, i YH, et al. Combined T/Y biliary stent placement for the treatment of biliary obstruction caused by ismuth-corlett type IV hilar cholangiocarcinoma. Hepatogastroenterology. 2014;61:1519-22. 19. De Palma GD, Pezzullo, Rega M, Persico M, Patrone F, Mastantuono L, et al. Unilateral placement of metallic stents for malignant hilar obstruction: a prospective study. Gastrointest Endosc. 2003;58:50-3. 20. Polydorou, Cairns SR, Dowsett JF, Hatfield R, Salmon PR, Cotton P, et al. Palliation of proximal malignant biliary obstruction by endoscopic endoprosthesis insertion. Gut. 1991;32:685-9. 21. urke DR, McLean GK. Obstructions of the hepatic duct confluence: internal drainage of bilateral lesions with a single catheter. Radiology. 1989;172:1035-8. 22. Chang WH, Kortan P, Haber G. Outcome in patients with bifurcation tumors who undergo unilateral versus bilateral hepatic duct drainage. Gastrointest Endosc. 1998;47:354-62. 23. Naitoh I, Ohara H, Nakazawa T, ndo T, Hayashi K, Okumura F, et al. Unilateral versus bilateral endoscopic metal stenting for malignant hilar biliary obstruction. J Gastroenterol Hepatol. 2009;24:552-7. 24. dam. Metallic biliary endoprostheses. Cardiovasc Intervent Radiol. 1994;17: 127-32. 25. Silverman W, Slivka. New technique for bilateral metal mesh stent insertion to treat hilar cholangiocarcinoma. Gastrointest Endosc. 1996;43:61-3. 26. Yamakado K, Nakatsuka, Iwata M, Kondo, Isaji S, Uemoto S, et al. Refractory biliary leak from intrahepatic biliary-enteric anastomosis treated by selective portal vein embolization. J Vasc Interv Radiol. 2002;13:1279-81. 27. Sadakari Y, Miyoshi, Ohtsuka T, Kohya N, Takahashi T, Matsumoto K, et al. Percutaneous transhepatic portal embolization for persistent bile leakage after hepatic resection: report of a case. Surg Today. 2008;38:668-71. 28. Hann LE, Getrajdman GI, rown KT, ach M, Teitcher J, Fong Y, et al. Hepatic lobar atrophy: association with ipsilateral portal vein obstruction. JR m J Roentgenol. 1996;167:1017-21. 29. Takayasu K, Muramatsu Y, Shima Y, Moriyama N, Yamada T, Makuuchi M. Hepatic lobar atrophy following obstruction of the ipsilateral portal vein from hilar cholangiocarcinoma. Radiology. 1986;160:389-93. 30. Schoder M, Rossi P, Uflacker R, ezzi M, Stadler, Funovics M, et al. Malignant biliary obstruction: treatment with eptfe-fep- covered endoprostheses initial technical and clinical experiences in a multicenter trial. Radiology. 2002;225:35-42. 31. Hatzidakis, Krokidis M, Kalbakis K, Romanos J, Petrakis I, Gourtsoyiannis N. eptfe/fep-covered metallic stents for palliation of malignant biliary disease: can tumor ingrowth be prevented? Cardiovasc Intervent Radiol. 2007;30:950-8. 32. Han YM, Kwak HS, Jin GY, Lee SO, Chung GH. Treatment of malignant biliary obstruction with a PTFE-covered self-expandable nitinol stent. Korean J Radiol. 2007;8:410-7. 33. Gwon DI, Ko GY, Sung K, Yoon HK, Shin JH, Kim JH, et al. novel double stent system for palliative treatment of malignant extrahepatic biliary obstructions: a pilot study. JR m J Roentgenol. 2011;197:W942-7. 34. Gwon DI, Ko GY, Kim JH, Yoon HK, Lee IS, Kim K, et al. comparative analysis of PTFE-covered and uncovered stents for palliative treatment of malignant extrahepatic biliary obstruction. JR m J Roentgenol. 2010;195:W463-9. 35. Yi R, Gwon DI, Ko GY, Yoon HK, Kim JH, Shin JH, et al. Percutaneous unilateral placement of biliary covered metallic stent in patients with malignant hilar biliary obstruction and contralateral portal vein occlusion. cta Radiol. 2012;53:742-9.