- Email: [email protected]
Toward a better biliary confluence stent
Topazian
Editorial
5. Polydorou AA, Cairns SR, Dowsett JF, et al. Palliation of proximal malignant biliary obstruction by endoscopic endoprosthesis insertion. Gut 1991;32:685-9. 6. Dowsett JF, Vaira D, Hatfield ARW, et al. Endoscopic biliary therapy using the combined percutaneous and endoscopic technique. Gastroenterology 1989;96:1180-6. 7. Ducreux M, Liguory C, Lefebvre JF, et al. Management of malignant hilar biliary obstruction by endoscopy. Dig Dis Sci 1992;37:778-83. 8. Robertson DAF, Hacking CN, Birch S, et al. Experience with a combined percutaneous and endoscopic approach to stent insertion in malignant obstructive jaundice. Lancet 1987;II:1449-52. 9. Cheung KL, Lai ES. Endoscopic stenting for malignant biliary obstruction. Arch Surg 1995;130:204-7. 10. Bismuth H, Castaing D, Traynor O. Resection or palliation: priority of surgery in the treatment of hilar cancer. World J Surg 1988;12:39-47. 11. Cotton PB, Lehman G, Vennes J, et al. Endoscopic sphincterotomy complications and their management: an attempt at consensus. Gastrointest Endosc 1991;37:383-93. 12. Sherman S. Endoscopic drainage of malignant hilar obstruction: is one biliary stent enough or should we work to place two? Gastrointest Endosc 2001;53:681-4. 13. Silverman W, Slivka A. New technique for bilateral metal mesh stent insertion to treat hilar cholangiocarcinoma. Gastrointest Endosc 1996;43:61-3.
14. Dumas R, Demuth N, Buckley M, et al. Endoscopic bilateral metal stent placement for malignant hilar stenoses: identification of optimal technique. Gastrointest Endosc 2000;51:334-8. 15. Cheng JL, Bruno MJ, Bergman JJ, et al. Endoscopic palliation of patients with biliary obstruction caused by unresectable hilar cholangiocarcinoma: efficacy of self-expandable metallic Wallstents. Gastrointest Endosc 2002;56:33-9. 16. De Palma GD, Galloro G, Siciliano S, et al. Unilateral versus bilateral endoscopic hepatic duct drainage in patients with malignant hilar biliary obstruction: results of a prospective, randomized, and controlled study. Gastrointest Endosc 2001;53:547-53.
Received October 5, 2006. Accepted December 26, 2006. Current affiliations: Department of Internal Medicine (J.H.L., D.H.K., J.Y.K., S.M.L., D.H.K., C.W.P., H.S.C., G.H.K., T.O.K., J.H., G.A.S., M.C.), Department of Radiology (S.K., C.W.K., J.W.L.), Pusan National University College of Medicine, Busan, Korea. Reprint requests: Dae Hwan Kang, MD, Department of Internal Medicine, Pusan National University College of Medicine, 1-10 Ami-dong, Seo-Gu, Busan 602-739, Korea.
EDITORIAL
Toward a better biliary confluence stent
A Y-shaped stent designed for the carina was placed via a rigid bronchoscope in 19821; 6 years later a Y-shaped biliary confluence stent was placed endoscopically by Hauenstein et al,2 who fabricated a 14F plastic stent, and passed it into the biliary tree via the duodenum over percutaneously placed bilateral biliary guidewires. Subsequent innovations in stent design have not specifically addressed the biliary confluence, although endoscopic palliation of hilar malignant obstruction has improved thanks to improved endoscopic technique, the use of self-expanding metal stents (SEMSs), and the development of biliary brachytherapy3,4 and photodynamic therapy (PDT).5 Although palliative PDT5 and curative liver transplantation for unresectable malignant biliary disease6 have been shown to offer better patient outcomes than palliative stent placement alone, some patients (particularly those with metastatic disease) may not be candidates for these therapies. In this issue of Gastrointestinal Endoscopy, Lee et al7 present their initial endoscopic experience
with a straight SEMS specifically designed to simplify palliative stent placement of hilar malignant biliary obstruction. Their work illustrates the potential for renewed innovation in biliary stent technology.
Endoscopic palliation of hilar malignant obstruction has improved thanks to improved endoscopic technique, the use of self-expanding metal stents, the development of biliary brachytherapy, and photodynamic therapy.
Copyright ª 2007 by the American Society for Gastrointestinal Endoscopy 0016-5107/$32.00 doi:10.1016/j.gie.2007.02.047
Hilar malignant biliary obstruction poses particular challenges for endoscopists.8 Poor patient outcomes are, in part, because of infection of contaminated, undrained intrahepatic ducts after ERCP. Results improve when the biliary endoscopist fills only those intrahepatic ducts that they can drain with stents, by using CT or magnetic resonance images to plan the ERCP procedure and steerable guidewires to access the desired ducts before intrahepatic contrast injection.9-11 Typically, drainage of 1 hepatic
www.giejournal.org
Volume 66, No. 2 : 2007 GASTROINTESTINAL ENDOSCOPY 369
Editorial
Topazian
lobe (in Bismuth II and III tumors) or the largest hepatic sectoral duct (in Bismuth IV tumors) achieves adequate palliation of jaundice,8,11,12 and a randomized prospective study showed no benefit to routine bilateral plastic stent placement.9 Nevertheless, endoscopists sometimes introduce contrast into 2 or more separate intrahepatic systems above a hilar obstruction, either unintentionally, to achieve sufficient palliation of jaundice (especially in some Bismuth IV tumors), to facilitate PDT or brachytherapy,3,5 or in the belief that drainage of the entire biliary tree will improve patient outcomes.13 In these cases, multiple stents should be placed. Plastic stents are the best choice in resection candidates, as well as in patients who may qualify for liver transplantation,6 and are probably preferred in patients who will undergo brachytherapy3 or PDT.5 SEMSs, which have a longer average patency than plastic stents, are preferred in patients who are not candidates for any of these antitumor therapies. In the absence of a truly Y-shaped SEMS, the creation of a Y-shaped stent configuration across the biliary confluence requires placement of multiple straight SEMSs in either a nested or a parallel configuration. Most American endoscopists use a nested technique, in which an uncoated SEMS is first deployed across the confluence to 1 portion of the intrahepatic biliary tree. Guidewire access to undrained ductal segments is then obtained through the interstices of the first SEMS, and a second (and possibly third) uncoated SEMS is deployed through the interstices of the first stent. A SEMS with relatively large interstices is typically placed first, to facilitate subsequent passage of other SEMS delivery catheters. With some SEMS designs, an interstice may have to be dilated or fractured with a stent retrieval device to permit placement of additional stents. A nested Y-shaped SEMS configuration usually provides good drainage but can be technically difficult to achieve. The endoscopist may fail to access additional intrahepatic ductal systems through the interstices of the first SEMS, leaving the patient with contaminated, undrained intrahepatic ducts that will require percutaneous drainage. In addition, a nested SEMS configuration can be difficult to revise when tumor ingrowth obstructs the stents. An alternative Y-shaped stent placement technique deploys the straight SEMS in parallel, so that the shafts of the 2 stents are side by side in the common duct. This can be impossible once 1 SEMS has been deployed, even if a second guidewire is already in place beside it, because the distal tines of the first stent may press into the bile-duct wall and prevent passage of the second SEMS-delivery catheter past the distal end of the first SEMS. Two solutions to this problem have been described; the first requires placement of a very long first SEMS that extends from the intrahepatic ducts into the duodenum; however, metal stents of the necessary length are not marketed in North America. The other solution is to place a temporary plastic stent to the distal end of the malignant stricture, as
well as guidewires to both intrahepatic ductal systems, before placement of the first SEMS.13 The plastic stent props the distal tines of the deployed first SEMS away from the bile-duct wall and allows passage of a second SEMS-delivery catheter alongside the first SEMS. The second SEMS is deployed so that the distal ends of the 2 SEMSs are aligned, and the plastic stent is then removed. This approach facilitates subsequent endoscopic access to both drained ductal segments. Subsequent bilateral access may still be difficult, however, if the distal ends of the 2 stents are not properly aligned. Lee et al,7 used a straight SEMS of novel design (termed ‘‘Kim stent’’ in a previous publication14) to facilitate nested Y-shaped SEMS placement across the biliary confluence.7 The stent, which does not have a Y shape, is knit with both spiral and Z wire configurations, and features a central shaft section that omits the Z configuration, resulting in 8-mm interstices in the portion of the stent that straddles the confluence. The investigators initially reported percutaneous use of the Kim stent in 57 patients with malignant hilar biliary obstruction.14 The Kim stent was first deployed from the right to the left hepatic ducts via a percutaneous transhepatic tract, and a standard SEMS was then placed from the intrahepatic ducts to the common duct through the large central interstices of the Kim stent, resulting in a nested ‘‘T’’ SEMS configuration, draining the biliary confluence. The new stent appeared to simplify bilateral internal SEMS placement through a single percutaneous tract. Thirty-day mortality was 1.7%; mean survival and stent patency times were 194 days and 170 days, respectively; and stent obstruction occurred in 18% of patients, because tumor ingrowth or overgrowth.14 In the current report, the same stent design was used to facilitate endoscopic nested Y-shaped SEMS placement in 10 patients with hilar cholangiocarcinoma. After placing the novel SEMS across the biliary confluence (typically to the left duct), guidewire access to the other side of the biliary confluence was obtained through the large central interstices of the stent, and a second standard SEMS was deployed to the other side. Technical success was achieved in 8 of 10 patients; in the other 2, contralateral access through the large interstices of the Kim stent failed, despite use of multiple endoscopic accessories. In the 8 patients with successful stent placement, there was no 30-day mortality, median stent patency was 217 days, and stent obstruction occurred in 2 patients (25%), 1 of whom required percutaneous biliary drainage.7 The average stent-patency time compares favorably with previous reports of hilar stent placement with standard SEMSs.12 These pilot data suggest that the large central interstices of the Kim stent may simplify nested Y-shaped SEMS placement. Larger patient numbers and a matched control group are needed to determine if technical success rate, procedure time, average stent patency, and success rate of subsequent endoscopic interventions favor the new stent design. The investigators rightly point out that more study is needed.
370 GASTROINTESTINAL ENDOSCOPY Volume 66, No. 2 : 2007
www.giejournal.org
Topazian
This work highlights the potential for innovation in biliary confluence stent design. Although the plastic biliary Y-shaped stent designed and placed by Hauenstein et al2 in 1988 did not prove to be broadly applicable, soft plastic stents with a true Y shape are still used today by bronchoscopists: the 2 short arms of the stent are compressed side by side to allow stent delivery through a rigid bronchoscope. Similarly, stenosed coronary artery bifurcations pose a challenge to interventional cardiologists,15 who have responded with innovative SEMS designs, including bifurcated SEMSs.16 Like every biliary endoscopist who has wrestled with a difficult confluence obstruction, I look forward to the day when the Kim stent or other novel stent designs improve the ease, technical success, and patient outcomes of hilar biliary stent placement. DISCLOSURE The author has no conflicts of interest to report. Mark Topazian, MD The Miles and Shirley Fiterman Center for Digestive Diseases Division of Gastroenterology and Hepatology Department of Internal Medicine Mayo Clinic Rochester, Minnesota, USA REFERENCES 1. Westaby S, Jackson J, Pearson F. A bifurcated silicone rubber stent for relief of tracheo-bronchial obstruction. J Thorac Cardiovasc Surg 1982;83:414-7. 2. Hauenstein K, Beck A, Sontheimer J, et al. Eine neue Y-endoprothese zur drainage von gallengangsverschlussen der hepaticusgabel. Radiologe 1988;28:243-6.
www.giejournal.org
Editorial 3. Simmons D, Baron T, Petersen B, et al. A novel endoscopic approach to brachytherapy in the management of hilar cholangiocarcinoma. Am J Gastroenterol 2006;101:1792-6. 4. Ishii H, Furuse J, Nagase M, et al. Relief of jaundice by external beam radiotherapy and intraluminal brachytherapy in patients with extrahepatic cholangiocarcinoma: results without stenting. Hepatogastroenterology 2004;51:954-7. 5. Ortner M, Caca K, Berr F, et al. Successful photodynamic therapy for nonresectable cholangiocarcinoma: a randomized prospective study. Gastroenterology 2003;125:1355-63. 6. Heimbach J, Gores G, Nagorney D, et al. Liver transplantation for perihilar cholangiocarcinoma after aggressive neoadjuvant therapy: a new paradigm for liver and biliary malignancies? Surgery 2006;140:331-4. 7. Lee JH, Kang DH, Kim JY, et al. Endoscopic bilateral metal stent placement for advanced hilar cholangiocarcinoma: a pilot study of a newly designed Y stent. Gastrointest Endosc 2007;66:364-9. 8. Sherman S. Endoscopic drainage of malignant hilar obstruction: is one biliary stent enough or should we work to place two? Gastrointest Endosc 2001;53:681-4. 9. De Palma G, Galloro G, Siciliano S, et al. Unilateral versus bilateral endoscopic hepatic duct drainage in patients with malignant hilar biliary obstruction: results of a prospective, randomized, and controlled study. Gastrointest Endosc 2001;53:547-53. 10. Chang W, Kortan P, Haber G. Outcome in patients with bifurcation tumors who undergo unilateral versus bilateral hepatic duct drainage. Gastrointest Endosc 1998;47:354-62. 11. Freeman M, Overby CS. Selective MRCP and CT-targeted drainage of malignant hilar biliary obstruction with self-expanding metallic stents. Gastrointest Endosc 2003;58:41-9. 12. De Palma G, Pezzullo A, Rega M, et al. Unilateral placement of metallic stents for malignant hilar obstruction: a prospective study. Gastrointest Endosc 2003;58:50-3. 13. Hookey L, Le Moine O, Deviere J. Use of a temporary plastic stent to facilitate the placement of multiple self-expanding metal stents in malignant biliary hilar strictures. Gastrointest Endosc 2005;62:605-9. 14. Kim C, Park A, Won J, et al. T-configured dual stent placement in malignant biliary hilar duct obstructions with a newly designed stent. J Vasc Interv Radiol 2004;15:713-7. 15. Johnston P. Y stenting of a bifurcation stenosis using a new radiopaque stent. J Interv Cardiol 2001;14:21-5. 16. Louvard Y, Lefevre T, Morice M. Percutaneous coronary intervention for bifurcation coronary disease. Heart 2004;90:713-22.
Volume 66, No. 2 : 2007 GASTROINTESTINAL ENDOSCOPY 371
Editorial
5. Polydorou AA, Cairns SR, Dowsett JF, et al. Palliation of proximal malignant biliary obstruction by endoscopic endoprosthesis insertion. Gut 1991;32:685-9. 6. Dowsett JF, Vaira D, Hatfield ARW, et al. Endoscopic biliary therapy using the combined percutaneous and endoscopic technique. Gastroenterology 1989;96:1180-6. 7. Ducreux M, Liguory C, Lefebvre JF, et al. Management of malignant hilar biliary obstruction by endoscopy. Dig Dis Sci 1992;37:778-83. 8. Robertson DAF, Hacking CN, Birch S, et al. Experience with a combined percutaneous and endoscopic approach to stent insertion in malignant obstructive jaundice. Lancet 1987;II:1449-52. 9. Cheung KL, Lai ES. Endoscopic stenting for malignant biliary obstruction. Arch Surg 1995;130:204-7. 10. Bismuth H, Castaing D, Traynor O. Resection or palliation: priority of surgery in the treatment of hilar cancer. World J Surg 1988;12:39-47. 11. Cotton PB, Lehman G, Vennes J, et al. Endoscopic sphincterotomy complications and their management: an attempt at consensus. Gastrointest Endosc 1991;37:383-93. 12. Sherman S. Endoscopic drainage of malignant hilar obstruction: is one biliary stent enough or should we work to place two? Gastrointest Endosc 2001;53:681-4. 13. Silverman W, Slivka A. New technique for bilateral metal mesh stent insertion to treat hilar cholangiocarcinoma. Gastrointest Endosc 1996;43:61-3.
14. Dumas R, Demuth N, Buckley M, et al. Endoscopic bilateral metal stent placement for malignant hilar stenoses: identification of optimal technique. Gastrointest Endosc 2000;51:334-8. 15. Cheng JL, Bruno MJ, Bergman JJ, et al. Endoscopic palliation of patients with biliary obstruction caused by unresectable hilar cholangiocarcinoma: efficacy of self-expandable metallic Wallstents. Gastrointest Endosc 2002;56:33-9. 16. De Palma GD, Galloro G, Siciliano S, et al. Unilateral versus bilateral endoscopic hepatic duct drainage in patients with malignant hilar biliary obstruction: results of a prospective, randomized, and controlled study. Gastrointest Endosc 2001;53:547-53.
Received October 5, 2006. Accepted December 26, 2006. Current affiliations: Department of Internal Medicine (J.H.L., D.H.K., J.Y.K., S.M.L., D.H.K., C.W.P., H.S.C., G.H.K., T.O.K., J.H., G.A.S., M.C.), Department of Radiology (S.K., C.W.K., J.W.L.), Pusan National University College of Medicine, Busan, Korea. Reprint requests: Dae Hwan Kang, MD, Department of Internal Medicine, Pusan National University College of Medicine, 1-10 Ami-dong, Seo-Gu, Busan 602-739, Korea.
EDITORIAL
Toward a better biliary confluence stent
A Y-shaped stent designed for the carina was placed via a rigid bronchoscope in 19821; 6 years later a Y-shaped biliary confluence stent was placed endoscopically by Hauenstein et al,2 who fabricated a 14F plastic stent, and passed it into the biliary tree via the duodenum over percutaneously placed bilateral biliary guidewires. Subsequent innovations in stent design have not specifically addressed the biliary confluence, although endoscopic palliation of hilar malignant obstruction has improved thanks to improved endoscopic technique, the use of self-expanding metal stents (SEMSs), and the development of biliary brachytherapy3,4 and photodynamic therapy (PDT).5 Although palliative PDT5 and curative liver transplantation for unresectable malignant biliary disease6 have been shown to offer better patient outcomes than palliative stent placement alone, some patients (particularly those with metastatic disease) may not be candidates for these therapies. In this issue of Gastrointestinal Endoscopy, Lee et al7 present their initial endoscopic experience
with a straight SEMS specifically designed to simplify palliative stent placement of hilar malignant biliary obstruction. Their work illustrates the potential for renewed innovation in biliary stent technology.
Endoscopic palliation of hilar malignant obstruction has improved thanks to improved endoscopic technique, the use of self-expanding metal stents, the development of biliary brachytherapy, and photodynamic therapy.
Copyright ª 2007 by the American Society for Gastrointestinal Endoscopy 0016-5107/$32.00 doi:10.1016/j.gie.2007.02.047
Hilar malignant biliary obstruction poses particular challenges for endoscopists.8 Poor patient outcomes are, in part, because of infection of contaminated, undrained intrahepatic ducts after ERCP. Results improve when the biliary endoscopist fills only those intrahepatic ducts that they can drain with stents, by using CT or magnetic resonance images to plan the ERCP procedure and steerable guidewires to access the desired ducts before intrahepatic contrast injection.9-11 Typically, drainage of 1 hepatic
www.giejournal.org
Volume 66, No. 2 : 2007 GASTROINTESTINAL ENDOSCOPY 369
Editorial
Topazian
lobe (in Bismuth II and III tumors) or the largest hepatic sectoral duct (in Bismuth IV tumors) achieves adequate palliation of jaundice,8,11,12 and a randomized prospective study showed no benefit to routine bilateral plastic stent placement.9 Nevertheless, endoscopists sometimes introduce contrast into 2 or more separate intrahepatic systems above a hilar obstruction, either unintentionally, to achieve sufficient palliation of jaundice (especially in some Bismuth IV tumors), to facilitate PDT or brachytherapy,3,5 or in the belief that drainage of the entire biliary tree will improve patient outcomes.13 In these cases, multiple stents should be placed. Plastic stents are the best choice in resection candidates, as well as in patients who may qualify for liver transplantation,6 and are probably preferred in patients who will undergo brachytherapy3 or PDT.5 SEMSs, which have a longer average patency than plastic stents, are preferred in patients who are not candidates for any of these antitumor therapies. In the absence of a truly Y-shaped SEMS, the creation of a Y-shaped stent configuration across the biliary confluence requires placement of multiple straight SEMSs in either a nested or a parallel configuration. Most American endoscopists use a nested technique, in which an uncoated SEMS is first deployed across the confluence to 1 portion of the intrahepatic biliary tree. Guidewire access to undrained ductal segments is then obtained through the interstices of the first SEMS, and a second (and possibly third) uncoated SEMS is deployed through the interstices of the first stent. A SEMS with relatively large interstices is typically placed first, to facilitate subsequent passage of other SEMS delivery catheters. With some SEMS designs, an interstice may have to be dilated or fractured with a stent retrieval device to permit placement of additional stents. A nested Y-shaped SEMS configuration usually provides good drainage but can be technically difficult to achieve. The endoscopist may fail to access additional intrahepatic ductal systems through the interstices of the first SEMS, leaving the patient with contaminated, undrained intrahepatic ducts that will require percutaneous drainage. In addition, a nested SEMS configuration can be difficult to revise when tumor ingrowth obstructs the stents. An alternative Y-shaped stent placement technique deploys the straight SEMS in parallel, so that the shafts of the 2 stents are side by side in the common duct. This can be impossible once 1 SEMS has been deployed, even if a second guidewire is already in place beside it, because the distal tines of the first stent may press into the bile-duct wall and prevent passage of the second SEMS-delivery catheter past the distal end of the first SEMS. Two solutions to this problem have been described; the first requires placement of a very long first SEMS that extends from the intrahepatic ducts into the duodenum; however, metal stents of the necessary length are not marketed in North America. The other solution is to place a temporary plastic stent to the distal end of the malignant stricture, as
well as guidewires to both intrahepatic ductal systems, before placement of the first SEMS.13 The plastic stent props the distal tines of the deployed first SEMS away from the bile-duct wall and allows passage of a second SEMS-delivery catheter alongside the first SEMS. The second SEMS is deployed so that the distal ends of the 2 SEMSs are aligned, and the plastic stent is then removed. This approach facilitates subsequent endoscopic access to both drained ductal segments. Subsequent bilateral access may still be difficult, however, if the distal ends of the 2 stents are not properly aligned. Lee et al,7 used a straight SEMS of novel design (termed ‘‘Kim stent’’ in a previous publication14) to facilitate nested Y-shaped SEMS placement across the biliary confluence.7 The stent, which does not have a Y shape, is knit with both spiral and Z wire configurations, and features a central shaft section that omits the Z configuration, resulting in 8-mm interstices in the portion of the stent that straddles the confluence. The investigators initially reported percutaneous use of the Kim stent in 57 patients with malignant hilar biliary obstruction.14 The Kim stent was first deployed from the right to the left hepatic ducts via a percutaneous transhepatic tract, and a standard SEMS was then placed from the intrahepatic ducts to the common duct through the large central interstices of the Kim stent, resulting in a nested ‘‘T’’ SEMS configuration, draining the biliary confluence. The new stent appeared to simplify bilateral internal SEMS placement through a single percutaneous tract. Thirty-day mortality was 1.7%; mean survival and stent patency times were 194 days and 170 days, respectively; and stent obstruction occurred in 18% of patients, because tumor ingrowth or overgrowth.14 In the current report, the same stent design was used to facilitate endoscopic nested Y-shaped SEMS placement in 10 patients with hilar cholangiocarcinoma. After placing the novel SEMS across the biliary confluence (typically to the left duct), guidewire access to the other side of the biliary confluence was obtained through the large central interstices of the stent, and a second standard SEMS was deployed to the other side. Technical success was achieved in 8 of 10 patients; in the other 2, contralateral access through the large interstices of the Kim stent failed, despite use of multiple endoscopic accessories. In the 8 patients with successful stent placement, there was no 30-day mortality, median stent patency was 217 days, and stent obstruction occurred in 2 patients (25%), 1 of whom required percutaneous biliary drainage.7 The average stent-patency time compares favorably with previous reports of hilar stent placement with standard SEMSs.12 These pilot data suggest that the large central interstices of the Kim stent may simplify nested Y-shaped SEMS placement. Larger patient numbers and a matched control group are needed to determine if technical success rate, procedure time, average stent patency, and success rate of subsequent endoscopic interventions favor the new stent design. The investigators rightly point out that more study is needed.
370 GASTROINTESTINAL ENDOSCOPY Volume 66, No. 2 : 2007
www.giejournal.org
Topazian
This work highlights the potential for innovation in biliary confluence stent design. Although the plastic biliary Y-shaped stent designed and placed by Hauenstein et al2 in 1988 did not prove to be broadly applicable, soft plastic stents with a true Y shape are still used today by bronchoscopists: the 2 short arms of the stent are compressed side by side to allow stent delivery through a rigid bronchoscope. Similarly, stenosed coronary artery bifurcations pose a challenge to interventional cardiologists,15 who have responded with innovative SEMS designs, including bifurcated SEMSs.16 Like every biliary endoscopist who has wrestled with a difficult confluence obstruction, I look forward to the day when the Kim stent or other novel stent designs improve the ease, technical success, and patient outcomes of hilar biliary stent placement. DISCLOSURE The author has no conflicts of interest to report. Mark Topazian, MD The Miles and Shirley Fiterman Center for Digestive Diseases Division of Gastroenterology and Hepatology Department of Internal Medicine Mayo Clinic Rochester, Minnesota, USA REFERENCES 1. Westaby S, Jackson J, Pearson F. A bifurcated silicone rubber stent for relief of tracheo-bronchial obstruction. J Thorac Cardiovasc Surg 1982;83:414-7. 2. Hauenstein K, Beck A, Sontheimer J, et al. Eine neue Y-endoprothese zur drainage von gallengangsverschlussen der hepaticusgabel. Radiologe 1988;28:243-6.
www.giejournal.org
Editorial 3. Simmons D, Baron T, Petersen B, et al. A novel endoscopic approach to brachytherapy in the management of hilar cholangiocarcinoma. Am J Gastroenterol 2006;101:1792-6. 4. Ishii H, Furuse J, Nagase M, et al. Relief of jaundice by external beam radiotherapy and intraluminal brachytherapy in patients with extrahepatic cholangiocarcinoma: results without stenting. Hepatogastroenterology 2004;51:954-7. 5. Ortner M, Caca K, Berr F, et al. Successful photodynamic therapy for nonresectable cholangiocarcinoma: a randomized prospective study. Gastroenterology 2003;125:1355-63. 6. Heimbach J, Gores G, Nagorney D, et al. Liver transplantation for perihilar cholangiocarcinoma after aggressive neoadjuvant therapy: a new paradigm for liver and biliary malignancies? Surgery 2006;140:331-4. 7. Lee JH, Kang DH, Kim JY, et al. Endoscopic bilateral metal stent placement for advanced hilar cholangiocarcinoma: a pilot study of a newly designed Y stent. Gastrointest Endosc 2007;66:364-9. 8. Sherman S. Endoscopic drainage of malignant hilar obstruction: is one biliary stent enough or should we work to place two? Gastrointest Endosc 2001;53:681-4. 9. De Palma G, Galloro G, Siciliano S, et al. Unilateral versus bilateral endoscopic hepatic duct drainage in patients with malignant hilar biliary obstruction: results of a prospective, randomized, and controlled study. Gastrointest Endosc 2001;53:547-53. 10. Chang W, Kortan P, Haber G. Outcome in patients with bifurcation tumors who undergo unilateral versus bilateral hepatic duct drainage. Gastrointest Endosc 1998;47:354-62. 11. Freeman M, Overby CS. Selective MRCP and CT-targeted drainage of malignant hilar biliary obstruction with self-expanding metallic stents. Gastrointest Endosc 2003;58:41-9. 12. De Palma G, Pezzullo A, Rega M, et al. Unilateral placement of metallic stents for malignant hilar obstruction: a prospective study. Gastrointest Endosc 2003;58:50-3. 13. Hookey L, Le Moine O, Deviere J. Use of a temporary plastic stent to facilitate the placement of multiple self-expanding metal stents in malignant biliary hilar strictures. Gastrointest Endosc 2005;62:605-9. 14. Kim C, Park A, Won J, et al. T-configured dual stent placement in malignant biliary hilar duct obstructions with a newly designed stent. J Vasc Interv Radiol 2004;15:713-7. 15. Johnston P. Y stenting of a bifurcation stenosis using a new radiopaque stent. J Interv Cardiol 2001;14:21-5. 16. Louvard Y, Lefevre T, Morice M. Percutaneous coronary intervention for bifurcation coronary disease. Heart 2004;90:713-22.
Volume 66, No. 2 : 2007 GASTROINTESTINAL ENDOSCOPY 371