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

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1 LIVER TRANSPLANTATION 17: , 2011 ORIGINAL ARTICLE Dual Catheter Placement Technique for Treatment of Biliary Anastomotic Strictures After Liver Transplantation Dong Il Gwon, 1 Kyu-Bo Sung, 1 Gi-Young Ko, 1 Hyun-Ki Yoon, 1 and Sung-Gyu Lee 2 1 Department of Radiology and Research Institute of Radiology and 2 Division of Hepatobiliary Surgery and Liver Transplantation, Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea The purpose of this study was to evaluate the results of percutaneous transhepatic management of anastomotic biliary strictures using the dual catheter placement technique (2 drainage catheters inserted via single percutaneous tract). The protocol of this retrospective study was approved by the institutional review board of our institution and written informed consent was waived. Percutaneous transhepatic biliary drainage and subsequent balloon dilation of anastomotic strictures were performed in 79 patients. Serial exchanges of drainage via catheter with larger diameters up to 14-French were performed at 1-month intervals followed by 3 exchanges of dual catheters at 2 month intervals. Drainage catheters were removed when follow-up cholangiography revealed improved strictures without recurrence of symptoms or elevation of biochemical findings. Technical success was achieved in all 79 (100%) patients after percutaneous transhepatic treatment. The mean period of dual catheter placement was months (range, months). Clinical success was achieved in 78 (98.7%) of 79 patients and drainage catheters were removed months (range, months) after the initial percutaneous transhepatic biliary drainage. Procedure-related complications occurred in 14 (17.8%) patients. During the mean followup period of months (range, months) in the 78 patients, the primary patency rates were 96%, 92%, and 91% at 1, 2, and 3 years, respectively. Seven (9%) of the 78 patients experienced recurrent symptoms at a mean of months (range, months) after catheter removal. In conclusion, the dual catheter placement technique seems to be an easy, safe, and effective method with an acceptable catheter intervention period for the treatment of anastomotic strictures following LDLT. Liver Transpl 17: , VC 2011 AASLD. Received July 29, 2010; accepted October 6, Anastomotic biliary strictures remain an important cause of morbidity following liver transplantation. For its management, endoscopic balloon dilation and stent placement have largely come to replace surgery as the first-line treatment option due to the lower morbidity and mortality rates. 1-5 Indeed, the success rate of endoscopic intervention in living donor liver transplantation (LDLT) has been reported to be between 64.5% and 86.4%. 3-5 However, there are still several problems to be overcome in the endoscopic intervention of LDLT, the main one being technical difficulty such as guide wire passage through tight strictures and hepaticojejunostomy (HJ) anastomosis. In such situations, percutaneous transhepatic treatment, including percutaneous transhepatic biliary drainage (PTBD), balloon dilation, and stent placement have been suggested as acceptable alternatives In previous reports, percutaneous treatment of anastomotic biliary strictures after liver transplantation have had varied results. Recurrent strictures after percutaneous transhepatic treatment of biliary strictures have been reported to occur in 16%-44% of cases, and the diameter of the drainage catheters used have been 8-French (Fr) to 18-Fr In the present Abbreviations: Fr, French; HBV, hepatitis B virus; HCC, hepatocellular carcinoma; HJ, hepaticojejunostomy; LDLT, living donor liver transplantation; OPD, outpatient department; PTBD, percutaneous transhepatic biliary drainage. Address reprint requests to Kyu-Bo Sung, M.D., Ph.D., Department of Radiology, Asan Medical Center, Poongnap-2-dong Songpa-ku, Seoul, , Korea. Telephone: ; FAX: ; kbsung@amc.seoul.kr DOI /lt View this article online at wileyonlinelibrary.com. LIVER TRANSPLANTATION.DOI /lt. Published on behalf of the American Association for the Study of Liver Diseases VC 2011 American Association for the Study of Liver Diseases.

2 160 GWON ET AL. LIVER TRANSPLANTATION, February 2011 study, we adopted the dual catheter placement technique (insertion of 2 drainage catheters via a single percutaneous tract) in order to achieve sufficient dilation of the stricture, and retrospectively evaluated the efficacy of repeat balloon dilation followed by dual catheter placement in 79 patients with anastomotic stricture following LDLT. PATIENTS AND METHODS Patient Population Between March 1999 and June 2006, 161 patients underwent LT followed by percutaneous transhepatic treatment to manage anastomotic strictures at our institution. Among them, 92 patients who had HJ biliary strictures were included in a previous report from our institution 12 and were thus excluded from our study, except for 14 patients who were included due to a recurrent anastomotic stricture after other percutaneous treatment. In addition, another 4 patients were ultimately excluded from the study, either because of patient death unrelated to percutaneous procedures (n ¼ 3) or reoperation at another hospital (n ¼ 1). Finally, 79 patients constituted the study population. The mean interval between the end of previous percutaneous treatment (drainage catheter removal) and recurrence in 14 patients was 21.9 months (range, months). In the remaining 65 patients, anastomotic stricture was initially diagnosed. A total of 44 patients of the 65 patients were converted to the dual catheter placement protocol after an initial other treatment protocol (repeat balloon dilation and 14-Fr catheter placement) due to persistent stricture, and 21 entered the dual catheter placement protocol at initial treatment of a new lesion. Demographic, clinical, and laboratory data were collected from patients medical records or from the electronic patient information database of our hospital (Table 1). The protocol of this retrospective study was approved by the institutional review board of our institution, and written informed consent was waived. The initial diagnosis of biliary stricture was based on combinations of clinical symptoms, biochemical data, and the results of imaging using various modalities, including ultrasonography, computed tomography, or diisopropyl iminodiacetic acid scan. The diagnosis was confirmed by percutaneous transhepatic cholangiography or endoscopic retrograde cholangiography. In our institution, a percutaneous procedure is performed as a first-line procedure for anastomotic stricture with HJ biliary reconstruction because surgeons had favored percutaneous transhepatic drainage with balloon dilatation over an endoscopic procedure. The percutaneous procedure was also selected for anastomotic strictures with duct-to-duct biliary reconstruction when endoscopic guide wire passage across the strictures had failed or by surgeon s preference in some cases. In this study, 29 patients underwent the endoscopic approach as the initial therapeutic method for biliary stricture. However, guide wire passage across the stricture had failed in 23 patients and effective biliary drainage via endoscopic nasobiliary drainage (n ¼ 3) or plastic stenting (n ¼ 3) had failed in 6 patients. Technique TABLE 1. Demographic Data of 79 Patients Number Classifications of Patients Percentage Sex Male Female Age (years) Mean Range Underlying diseases Liver cirrhosis (HBV) Liver cirrhosis (HBV) and HCC Liver cirrhosis (others)* Graft Living donor 79 Single lobe 68 (55/13) 86 (69.6/16.4) (right/left) Dual lobe 11 (6/5) 14 (7.6/6.4) (right/left) Type of biliary anastomosis Duct-to-duct Hepaticojejunostomy *Including fulminant hepatitis (n ¼ 9), primary biliary cirrhosis (n ¼ 2), liver cirrhosis (Wilson s disease) (n ¼ 2), primary sclerosing cholangitis (n ¼ 1), and cholangiocarcinoma (n ¼ 1). Our treatment protocol is summarized in Fig. 1. The intrahepatic bile duct was punctured with a 21-gauge Chiba needle (Cook, Bloomington, IN) under fluoroscopic or ultrasonographic guidance. The needle was then exchanged for a 5-Fr coaxial dilator and a 6-Fr to 7-Fr sheath (Terumo, Tokyo, Japan) over a inch or inch angled hydrophilic guide wire (Terumo). The inch guide wire and a 5-Fr cobra or Kumpe catheter (Cook) were used to traverse the stricture. Before inserting a drainage catheter, dilation of the stricture was performed using balloon catheters 6-8 mm in diameter (Cronus II; Medispes, Zug, Switzerland or Synergy; Boston Scientific, Galway, Ireland). An internal-external 8.5-Fr or 10-Fr drainage catheter (Cook) was then placed across the stricture. Serial exchanges of the internal drainage catheter for catheters of a larger diameter up to 14-Fr and repeated dilation of the stricture using a balloon catheter of a larger diameter up to 8-mm were performed at 1-month intervals on an outpatient basis.

3 LIVER TRANSPLANTATION, Vol. 17, No. 2, 2011 GWON ET AL. 161 Figure 1. Schematic diagram of our treatment protocol. To perform the dual catheter placement technique (Fig. 2), the 14-Fr catheter was removed over the guide wire (first guide wire) and a 12-Fr sheath was inserted over the first guide wire. Then, another inch guide wire was placed through the sheath, and the sheath was removed. A 14-Fr drainage catheter with multisided holes was inserted across the stricture over the 2 guide wires simultaneously, the first guide wire via the end hole of the 14-Fr catheter and the second guide wire via 1 side hole of the 14-Fr drainage catheter. The first guide wire was then removed and the 14-Fr catheter was cut 3-5 cm from the skin entry site. Next, an 8.5-Fr drainage catheter was inserted across the stricture over the second guide wire via the side hole of the 14-Fr drainage catheter. The 8.5-Fr drainage catheter was then cut, with the tips clamped to minimize discomfort from the drainage catheters. Figure 3 illustrates the schematic drawings of the dual catheter. Three sessions of repeat dual catheter exchanges after balloon dilation using an 8-mm balloon catheter were performed at 2-month intervals on an outpatient basis. After 3 sessions of dual catheter placement, if there was a patent anastomosis, an external 14-Fr catheter was placed and clamped for 1 month in order to evaluate the presence of elastic restricture. Before intrahepatic catheter placement, if the lesion showed a persistent stricture on cholangiography, additional dual catheter placement was performed to treat the persistent stricture. The drainage catheters were removed when cholangiography revealed fluent passage of contrast medium without recurrence of patient symptoms or changes in biochemical data. However, if there was restricture, dual catheters were replaced across the stricture for an additional 1 month or more following balloon dilation. Follow-Up Blood chemistry, including serum bilirubin and liver enzyme assay, was measured prior to PTBD on the day of drainage catheter exchanges and on the day of drainage catheter removal. Clinical and radiological data of all patients were also obtained in the liver transplant outpatient clinic. Following drainage catheter removal, patient symptoms and blood chemistry were routinely assessed every 8-12 weeks. Study Endpoints, Definitions, and Statistical Analysis Study endpoints were the assessment of technical success, clinical success, primary patency, and complications. Technical success was defined as successful

4 162 GWON ET AL. LIVER TRANSPLANTATION, February 2011 Figure 2. A case of anastomotic stricture treated with dual catheter placement. (A) Cholangiogram shows focal stricture of duct-to-duct anastomosis (black arrow). (B) Photography image shows the 14-Fr catheter (black arrow) placement via the first guide wire (black arrowhead) at the end of the 14-Fr catheter and via the second guide wire (white arrowhead) at the side hole of the 14-Fr catheter, simultaneously. (C) The 14-Fr catheter (black arrow) is inserted across the stricture while keeping the second guide wire (white arrowheads) in place. (D) The 8.5-Fr catheter (white arrows) is inserted over the second guide wire, exiting through the side hole of the 14Fr catheter. (E) Follow-up cholangiogram 6 months after dual stent placement shows a widened anastomotic stricture. (F) Cholangiogram obtained 4 weeks after positioning the tip of the 14-Fr catheter above the stricture shows the patent anastomosis (black arrow) with fluent passage of contrast medium.

5 LIVER TRANSPLANTATION, Vol. 17, No. 2, 2011 GWON ET AL. 163 TABLE 2. Characteristics of the Anastomotic Stricture in 79 Patients Figure 3. Schematic drawings of a dual catheter. (A) Schematic drawing of a dual catheter. Arrowheads indicate a side hole for the exit of an 8.5-Fr catheter. Arrows indicate the level of anastomotic stricture. (B) Schematic drawing of the axial view at each level (corresponding to dotted lines a, b, or c in panel A). Arrowheads indicate the exit side hole for the 8.5-Fr catheter. Number Characteristic of Patients Percentage Interval between LDLT and PTBD Mean months Range months 6 months >6 months Number of PTBD One PTBD Two PTBDs Cholangiographic finding Complete occlusion Stricture biliary drainage and balloon dilation followed by drainage catheter interposition across the biliary strictures. Clinical success was defined as the disappearance of patient symptoms and normalization of chemical data or their decrease to less than 1.5 times the normal levels after drainage catheter removal. Catheter independence was defined as the drainagecatheter-free status of the patients after treatment. Primary patency was defined as the time interval from drainage catheter removal to the detection of recurrent symptoms or the last follow-up. Complications were classified as major and minor according to guidelines from the Standards of Practice Committee of the Society of Interventional Radiology. 13 Major complications were defined as those necessitating major therapy, those necessitating an unplanned increase in the level of care or prolonged hospitalization (>48 hours), and those resulting in permanent adverse sequelae or death. Cholangitis was defined as leukocytosis, fever and chill, and worsening of liver function tests within 24 hours of the procedure. Severe hemobilia was defined as clinically significant bleeding requiring transfusion of blood and/or angiographic intervention. Bile ductal injury was defined as bile peritonitis or biloma detected by physical and radiologic examinations. Minor complications were defined as those requiring no therapy or nominal therapy, including overnight admission for observation only. Stent patency was estimated using life-table analysis according to the Kaplan-Meier method. All statistical analyses were conducted using SPSS software (version 14.0; SPSS, Inc., Chicago, IL). RESULTS Table 2 summarizes the characteristics of the anastomotic strictures in the 79 patients included in this study, and Fig. 4 summarizes the clinical outcomes. Mean interval between LDLT and PTBD was months (range, months). Sixty-six of the 79 patients could be treated with 1 PTBD (Fig. 3); Figure 4. Clinical outcomes of the 79 patients who had anastomotic biliary strictures. however, 13 patients required 2 PTBDs in order to treat 2 anastomotic strictures. Therefore, a total of 92 PTBDs were performed in 79 patients. Negotiation of biliary strictures and subsequent balloon dilations was technically successful in all patients after a mean of (range, 1-23) cannulation attempts. Removal of bile duct stones was also performed in 5 (6.3%) patients. A 14-Fr catheter placement across the stricture and subsequent insertion of an 8.5-Fr catheter via the side hole of the 14-Fr catheter was successful in all patients. The mean catheter intervention period was months (range, months) and the mean indwelling period of the dual catheter was months (range, months). Seventy-seven of the 79 patients could be treated with 3 sessions of dual catheter exchange for months (range, months); however, 2 patients required additional sessions of dual catheter placement for 12.2

6 164 GWON ET AL. LIVER TRANSPLANTATION, February 2011 TABLE 3. Procedure-Related Complications Following 92 PTBDs in 79 Patients Complications Number of Patients Incidence (%) Management Major Cholangitis Antibiotics and drainage catheter exchange Severe hemobilia Transarterial embolization (n ¼ 2), Portal vein embolization (n ¼1) Ductal injury (biloma) Aspiration Minor Catheter extraction Catheter reposition or reinsertion via a previous percutaneous tract Total Figure 5. Kaplan-Meier curve of primary patency after drainage catheter removal in 78 patients. and 14.2 months because of the restricture of the lesion prior to catheter removal. The mean catheter intervention period of the 21 patients who underwent our treatment protocol from the beginning was months (range, months), and the mean catheter intervention period of the remaining 58 patients from the other treatment protocol was months (range, months). Clinical success was achieved in 78 (98.7%) of 79 patients, and the drainage catheters were removed months (range, months) after the initial PTBD. The drainage catheter could not be removed in 1 (1.3%) of the 79 patients because of residual stricture requiring further indwelling of catheter placement. In this patient, cholangiography performed 4 weeks after intrahepatic positioning of the drainage catheter tip above the stricture showed significant restenosis as well as significant elevation in liver enzymes. Because of the risk of early recurrence, this patient underwent a repeat drainage catheter placement across the stricture following repeat balloon dilation. This patient has maintained the internal drainage catheter for 20.2 months as of this writing. Procedure-related complications that arose during treatment are summarized in Table 3. Major complications occurred in 10 sessions in 10 different patients and minor complications occurred during 4 sessions in 4 different patients. Five (6.4%) patients experienced cholangitis, probably due to catheter blockage and/or side branch occlusion by the catheter, and were treated through antibiotic therapy and catheter change. Three (3.8%) patients experienced severe hemobilia from the hepatic artery (n ¼ 2) and portal vein (n ¼ 1). The bleeding was successfully controlled in all 3 patients by coil embolization of the hepatic arteries and portal vein via the PTBD tract. Intrahepatic bilomas (n ¼ 2, 2.5%), probably due to PTBD, were detected incidentally by radiologic examination after catheter change. Percutaneous needle aspirations were performed for the 2 patients with biloma that was 3 cm and 4 cm in diameter. Four (5.1%) patients experienced complete or partial catheter extraction. Three patients required insertion of new PTBD catheters and 1 required repositioning of the PTBD catheter. Clinical follow-up until the end of this study was available for all patients. The cutoff date for data analysis was May 30, During the mean followup period of months (range, months) in the 78 patients, the primary patency rates were 96%, 92%, and 91% at 1, 2, and 3 years, respectively (Fig. 5). Seven (9%) of the 78 patients experienced recurrent symptoms at a mean of months (range, months) after catheter removal. Four patients had HJ anastomotic stricture and 3 had duct-to-duct anastomotic stricture. Among the 7 patients who had recurrent stricture after dual catheter placement and catheter removal, 5 patients had a history of persistent stricture during other percutaneous treatments and 2 had a recurrent stricture after another percutaneous treatment. Four of the 7 patients with recurrence underwent repeat PTBD with subsequent balloon dilation to treat recurrent biliary strictures and 4 patients still maintain drainage catheters. The other 3 patients underwent endoscopic drainage with subsequent plastic stent placement and still maintain plastic stents. DISCUSSION This study is a large retrospective study including 79 patients with anastomotic strictures after LDLT. In this study, we found that the primary patency rates

7 LIVER TRANSPLANTATION, Vol. 17, No. 2, 2011 GWON ET AL. 165 were 96%, 92%, and 91% at 1, 2, and 3 years, respectively. The 3-year primary patency rate of this study was superior to the 52.0%-82.3% 3-year primary patency rates reported in previous studies In a previous study performed in our institution, which used repeat balloon dilation and 8.5-Fr to 14-Fr drainage catheter placements for months, Ko et al. reported that 1-year and 3-year primary patency rates were 95.3% and 80.9%, respectively. 12 They, therefore, suggested that a sufficiently large-diameter drainage catheter with long-term placement was needed to minimize the incidence of early recurrence following drainage catheter removal. Although a relatively long duration (mean, months [range, months] in 21 patients who underwent our treatment protocol from the beginning) was necessary in order to treat the anastomotic stricture after LDLT in this study, the recurrence rate of 9% was also superior to the 15.8%-44% recurrence rates reported in previous studies In addition, our observed clinical success and catheter independence rate, which were both 98.8% (78 of 79 patients), were comparable to the 51%- 100% clinical success rates and 93.8%-94.9% catheter independence rates reported in previous studies The principal advantage of the dual catheter placement technique is that larger size dilation up to Fr and multiple balloon dilations can achieve effective stricture dilation without a percutaneous tract dilation of more than 14-Fr. Moreover, long-term maintenance (more than 6 months) of the dual catheters produces a similar effect as with stenting. Although placement of a large-bore catheter greater than 14-Fr may be effective for the treatment of biliary strictures, patients will be subject to greater discomfort and in addition, complication rates may increase. In one such study performed by Choo et al., 10 a large-bore catheter (14-Fr to 18-Fr) maintenance method was used to treat anastomotic strictures after LDLT, and they reported a relatively high rate of cholangitis (25%). Moreover, because intrahepatic bile ducts do not always sufficiently dilate in spite of the strictures, placement of a large-bore catheter greater than 14-Fr may not be technically feasible and furthermore, segmental cholangitis or liver abscess can be formed. This is one reason why large-bore catheter management of biliary strictures in liver transplantation is difficult. In this study using the dual catheter placement technique, the 14-Fr percutaneous tract diameter was relatively tolerable in all patients. In addition, only 5 (6.4%) patients had cholangitis which was treated with antibiotics and a catheter change. In this study, before the dual catheter placement, 58 patients had recurrent or persistent strictures after long-term treatment with a 14-Fr drainage catheter and repeat balloon dilation. Among them, 7 of the patients had a recurrence after the dual catheter placement technique. We could not analyze the risk factors for recurrence because the number of recurrences was small, however, we could consider that a large-diameter dilation of the anastomotic stricture might have been one of the important factors for treatment success. Although there is no consensus regarding the best period to place the indwelling catheter, we thought that the mean treatment period of months (range, months) in 21 patients who underwent our treatment protocol from the beginning was an acceptable period of catheter intervention, and our low recurrence rate may validate our procedure. In order to shorten the duration of catheter intervention, however, a retrievable stent-graft may be another possible option. Previous studies have reported that placement and removal of a retrievable biliary stent-graft for the treatment of benign biliary stricture was technically feasible 14,15 ; however, the studies did not deal with biliary strictures in liver transplant patients. Further investigation is needed to evaluate the efficacy of a retrievable stent for treatment of anastomotic strictures following LDLT. In conclusion, the 3-year primary patency rate of 91% and recurrence rate of 9% are clearly better than that of previously reported percutaneous treatments. Therefore, the dual catheter placement technique seems to be an easy, safe, and effective method with an acceptable catheter intervention period for treatment of anastomotic strictures following LDLT. REFERENCES 1. Rossi AF, Grosso C, Zanasi G, Gambitta P, Bini M, De Carlis L, et al. Long-term efficacy of endoscopic stenting in patients with stricture of the biliary anastomosis after orthotopic liver transplantation. Endoscopy 1998;30: Moser MA, Wall WJ. Management of biliary problems after liver transplantation. Liver Transpl 2001;7(11 Suppl 1):S46-S Hisatsune H, Yazumi S, Egawa H, Asada M, Hasegawa K, Kodama Y, et al. Endoscopic management of biliary strictures after duct-to-duct biliary reconstruction in right-lobe living-donor liver tansplantation. Transplantation 2003;76: Yazumi S, Yoshimoto T, Hisatsune H, Hasegawa K, Kida M, Tada S, et al. Endoscopic treatment of biliary complications after right-lobe living-donor liver transplantation with duct-to-duct biliary anastomosis. J Hepatobiliary Pancreat Surg 2006;13: Seo JK, Ryu JK, Lee SH, Park JK, Yang KY, Kim YT, et al. Endoscopic treatment for biliary stricture after adult living donor liver transplantation. Liver Transpl 2009;15: Righi D, Cesarani F, Muraro E, Gazzera C, Salizzoni M, Gandini G. Role of interventional radiology in the treatment of biliary strictures following orthotopic liver transplantation. Cardiovasc Intervent Radiol 2002;25: Roumilhac D, Poyet G, Sergent G, Declerck N, Karoui M, Mathurin P, et al. Long-term results of percutaneous management for anastomotic biliary stricture after orthotopic liver transplantation. Liver Transpl 2003;9: Sung RS, Campbell DA Jr, Rudich SM, Punch JD, Shieck VL, Armstrong JM, et al. Long-term follow-up of percutaneous transhepatic balloon cholangioplasty in the management of biliary strictures after liver transplantation. Transplantation 2004;77: Saad WE, Saad NE, Davies MG, Lee DE, Patel NC, Sahler LG, et al. Transhepatic balloon dilation of anastomotic biliary strictures in liver transplant recipients: the significance of a patent hepatic artery. J Vasc Interv Radiol 2005;16:

8 166 GWON ET AL. LIVER TRANSPLANTATION, February Choo SW, Shin SW, Do YS, Liu WC, Park KB, Sung YM, Choo IW. The balloon dilatation and large profile catheter maintenance method for the management of the bile duct stricture following liver transplantation. Korean J Radiol 2006;7: Zajko AB, Sheng R, Zetti GM, Madariaga JR, Bron KM. Transhepatic balloon dilation of biliary strictures in liver transplant patients: a 10-year experience. J Vasc Interv Radiol 1995;6: Ko GY, Sung KB, Yoon HK, Kim KR, Gwon DI, Lee SG. Percutaneous transhepatic treatment of hepaticojejunal anastomotic biliary strictures after living donor liver tansplantation. Liver Transpl 2008;14: Omary RA, Bettmann MA, Cardella JF, Bakal CW, Schwartzberg MS, Sacks D, et al. Quality improvement guidelines for the reporting and archiving of interventional radiology procedures. J Vasc Interv Radiol 2003; 14:S293-S Petersen BD, Timmermans HA, Uchida BT, Rabkin JM, Keller FS. Treatment of refractory benign biliary stenosis in liver transplant patients by placement and retrieval of a temporary stent-graft: work in progress. J Vasc Interv Radiol 2000;11: Gwon DI, Shim HJ, Kwak BK. Retrievable biliary stentgraft in the treatment of benign biliary strictures. J Vasc Interv Radiol 2008;19: