7256MULTICENTER RANDOMIZED COMPARATIVE TRIAL OF THENEW GIANTURCO SPIRAL Z-STENT COMPARED TO WALL-STENT: STUDY DESIGN AND PRELIMINARY REPORT OF THEZOOM STUDY.Douglas A. Howell, Glen A. Lehman, Stuart Sherman, John Baillie, M. S.Branch, Ram Chuttani, Douglas K. Pleskow, Willis G. Parsons, AdamSlivka, Paul A. Akerman, John J. Bosco, Maine Med Ctr, Portland, ME; IUMed Ctr, Indianapolis, IN; Duke Univ Med Ctr, Durham, NC; Beth IsraelDeaconess Hosp, Boston, MA; Northwestern Univ, Chicago, IL; Univ ofPittsburgh Med Ctr, Pittsburg, PA; Rhode Island Hosp, Providence, RI; StMary’s Duluth Clin, Duluth, MN.Introduction: Evaluation of long-term patency for devices introduced forthe treatment of extrahepatic malignant biliary obstruction require com-parative trials in view of the high degree of variability among patients.Reported stent patencies of newly introduced products are frequently notconfirmed in clinical practice (Gastrointest Endosc 1999:49:700(A)). Newproducts, particularly those involving high risk interventions and highcost, should be studied carefully in multicenter trials to gain consensus asto their clinical utility. We propose to study the new spiral stent for malig-nant obstruction compared to the other metal stent (ZOOM). Study Goal:All our participating centers have obtained IRB approval to offer appro-priate patients a randomized option of a standard uncoated Wallstent(Microvasive, Watertown, MA) or a new stainless steel uncoated Gianturcospiral Z-stent (Wilson-Cook, Winston-Salem, NC) for palliative treatmentof malignant extrahepatic biliary obstruction. All strictures must be 2 cmor more below the bifurcation and patients must be in good physical con-dition as measured by a Karnofsky score of 60 or higher (Requires occa-sional care for most needs). Patients with prior temporary plastic stentscan be accepted providing they do not show evidence of occlusion or cholan-gitis and have appropriate Karnofsky’s scores. Patients will then haveserum bilirubins measured at 1 month and clinical follow-up on a month-ly basis. Every effort will be made to determine the cause of stent occlu-sion. A study of sufficient power to detect a 20% difference in results hasbeen calculated to require 200 patients to be enrolled. Preliminary Results:24 patients have been randomized after successful guidewire placementthrough their malignant obstructions. 12 patients have receivedWallstents and 12 patients have received spiral Z-stents. There have beenno initial failures of stent placement. All patients have achieved initial bil-iary drainage. More extensive data of initial stent placement and initialdrainage will be forthcoming as patients are enrolled with long-termpatency data anticipated in the next 1-2 years. Conclusion: A large ran-domized controlled study of the newly introduced uncoated Gianturco spi-ral Z-stent is underway to compare procedural success, initial drainageand, most importantly, long-term patency. Such trials are needed to permitthe most appropriate employment of new devices.

7257ENDOSCOPIC BILIARY DRAINAGE WITH ENDOSCOPICPAPILLARY BALLOON DILATATION.Dae Hwan Kang, Geun Am Song, Mong Cho, Ung Suk Yang, Dept ofGastroenterology, Pusan, South Korea.Background: Endoscopic biliary drainage(EBD) for malignant obstructivejaundice is performed mostly with EST. But EST carries early complicationssuch as bleeding(especially), perforation and pancreatitis. We evaluated safe-ty and usefulness of EBD using endoscopic papillary balloon dilation(EPBD)without endoscopic sphincterotomy(EST). Methods: Fifteen patients weretreated form Jan. 1999 to June 1999 in Pusan National University Hospitaldue to malignant obstructive jaundice. EBD was performed using EPBD.When EPBD was performed, we used 8mm biliary balloon(Microvasive,Olbert). Pressure was applied at 120-170p.s.i for 1 minute. Diameter of plas-tic stent was 12Fr. They were investigated to estimate the usefulness andearly complications of EBD using EPBD. Results: Effective drainage wasachieved in 13 patients(87%). Procedure related complications developed intwo patients: acute pancreatitis in two(minimal or mild, 13%), hemorrhage inthree(clinically insignificant bleeding). Conclusion: EBD using EPBD is a safeand effective treatment method for malignant obstructive jaundice. However,prospective study is thought to be need in large patients group especially asto stent diameter and papilla size.

7258COMPARISON OF METAL STENTS IN THE MANAGEMENT OFMALIGNANT BILIARY OBSTRUCTION.Madhukar Kaw, Khurrum Shaikh, Praveena Kaw, Med Coll of Ohio,Toledo, OH; Brooks & Kushman, Southfield, MI.Background: Studies suggest more technical difficulty and less patencyrate for new ultraflex diamond stent (DS) compared to schneider wall-

stent (WS) for malignant biliary obstruction (MBO). Aim: To report ourexperience with new DS vs. WS in the management of MBO. Methods:Between 9/95 and 9/97, 14 patients had 18 WS (8 or 10mm in diameter/6.8or 8cm long) and between 9/97 and 8/99, 19 patients had 26 DS (10mm indiameter/6 or 8cm long)for palliation of MBO. Patients with death due toprior cholangitis, death due to liver failure and those lost to follow-up wereexcluded. Results: See table below. Conclusion: Our experience suggeststhat for matched population of patient with MBO, there is no significantdifference between DS and WS with the exception of better fluoroscopicvisualization with WS over DS.

Patients DS (n=19) WS (n=14)

Mean Age (yrs.) 66 71Sex (M/F) 11/8 8/6Pancreatic cancer 8 (42%) 7 (50%)Cholangio cancer 7 (36%) 5 (35%)Metastatic cancer 3 (16%) 2 (14%)Gallbladder cancer 1 (5%) 0EHD stricture 9 (47%) 7 (50%)IHD stricture 3 (16%) 3 (21%)EHD + IHD stricture 7 (37%) 4 (28%)Past Plastic Stents 9 (47%) 8 (57%)Stent Occlusion 3 (16%) 2 (14%)Mean Patency 6.9 mos. 7.1 mos.Tech. Difficulty 1 (5%) 0Fluor. Visualization Fair Good

EHD: extrahepatic duct, IHD: intrahepatic duct, Tech: technical, Fluor.:Fluoroscopic

7259WHICH ARE THE BEST METALLIC STENTS FOR PALLIATINGINOPERABLE MALIGNANT BILIARY STRICTURES; ORIGINAL,POLYURETHANE-COVERED OR NEWLY DESIGNED COVEREDMETALLIC STENT ? Yoshito Kawase, Tamon Sakai, Hiroaki Takami, Masayo Fujimoto,Masatoshi Kawanishi, Yuki Yamashiro, Tomio Yamasaki, Hideo Kitamura,Masahiro Fukuda, Yasushi Suzuki, Public Shiso Gen Hosp, Hyogo, Japan.BACKGROUND: Implantation of self-expanding metallic stents is anestablished palliation therapy for malignant biliary strictures. Wedesigned the polyurethane covered metallic stents and treated fiftypatients with them. We confirmed many merit of covered stents, but sev-eral complications after the stent implantation remain still now. Recentlywe newly modified covered metallic stents to avoid the stent migration.AIM: We studied the clinical effectiveness of the covered metallic stentsand the modified covered stents compared with the uncoverd stents.PATIENTS AND METHODS: Sixty eight patients (36 males, 32 females,mean age 73) with malignant biliary strictures have been treated withpolyurethane-covered metallic stents (n= 50), modified covered stents (n=8) and uncovered metallic stents (n= 10). We made the polyurethane mem-brane , using solid polyurethane and a glass tube and covered it outsidethe stent. We originally designed polyurethane membrane with the thick-ness of 0.05mm. Recently we modified the covered stent: i.e. we put thepolyurethane membrane inside the stent. We treated twenty eight patientstranshepaticaly and thirty eight endoscopically. For the hilar stricturestwo fully covered setnts were implanted like Y shape, using percutaneoustranshepatic cholangioscopy. RESULTS: Stent placement was technicallysuccessful in all patients. None of procedure-related complication was con-firmed. Patency period was 7.4 months of uncovered group and 11.84months of covered group in the longer follow-up period than six months.Stent obstruction due to tumor ingrowth occurred in five ptients (50%) ofuncovered metallic stents with a median time to obstruction of 24 weeksand none of covered group except two cases with tumor ingrowth due totechnical immaturity. Stent migration was cofirmed in four patients (8%)of fully covered group but not confirmed in the patients treated with themodified stents. Tumor overgrowth was confirmed in six patients (12%) ofcovered group because of short length of the stents. Mucosal hyperplasiawas confirmed in one patient (2%) of partially covered group. CONCLU-SION: We think that the covered and modified covered metallic stents aregood alternatives for palliating malignant biliary strictures. We believe thebest stent will be newly modified covered stent.

VOLUME 51, NO. 4, PART 2, 2000 GASTROINTESTINAL ENDOSCOPY AB307