nitinol and Bile-Duct-Neoplasms

The Ultraflex Diamond stent presents three features that might be of interest when treating biliary strictures: ease of insertion, high flexibility, and presentation of relatively large meshes. Limited clinical studies have shown its efficacy in relieving duct obstruction (in contrast with some other stent models, correct positioning of the Ultraflex Diamond stent provides adequate biliary drainage in almost all cases), and satisfactory long-term patency rates. The main improvement awaited is an efficient means to prevent late stent obstruction. The addition of coverage to this stent is feasible and could be the first step toward this goal.

Topics: Alloys; Bile Duct Neoplasms; Biocompatible Materials; Cholestasis; Endoscopy, Digestive System; Humans; Palliative Care; Pancreatic Neoplasms; Pliability; Prosthesis Implantation; Radiography; Stents; Treatment Outcome

Covered self-expandable metal stents (SEMSs) are increasingly used as alternatives to uncovered SEMSs for the palliation of inoperable malignant distal biliary obstruction to counteract tumor ingrowth. We aimed to compare the outcomes of partially covered and uncovered SEMSs with identical mesh structures and anti-migration properties, such as low axial force and flared ends.. One hundred and three patients who were diagnosed with inoperable malignant distal biliary obstruction between January 2006 and August 2013 were randomly assigned to either the partially covered (n = 51) or uncovered (n = 52) SEMS group.. There were no significant differences in the cumulative stent patency, overall patient survival, stent dysfunction-free survival and overall adverse events, including pancreatitis and cholecystitis, between the two groups. Compared to the uncovered group, stent migration (5.9% vs. 0%, p = 0.118) and tumor overgrowth (7.8% vs. 1.9%, p = 0.205) were non-significantly more frequent in the partially covered group, whereas tumor ingrowth showed a significantly higher incidence in the uncovered group (5.9% vs. 19.2%, p = 0.041). Stent migration in the partially covered group occurred only in patients with short stenosis of the utmost distal bile duct (two in ampullary cancer, one in bile duct cancer), and did not occur in any patients with pancreatic cancer.. For the palliation of malignant distal biliary obstruction, endoscopic placement of partially covered SEMSs with anti-migration designs and identical mesh structures to uncovered SEMSs failed to prolong cumulative stent patency or reduce stent migration.

Topics: Aged; Alloys; Bile Duct Neoplasms; Cholecystitis; Endoscopes, Gastrointestinal; Female; Humans; Kaplan-Meier Estimate; Male; Middle Aged; Palliative Care; Pancreatitis; Postoperative Complications; Proportional Hazards Models; Prospective Studies; Republic of Korea; Stents; Treatment Outcome

A high incidence of migration with covered metal stents has been reported in malignant gastric outlet obstruction (GOO). A newly modified, partially covered, triple-layer nitinol stent was developed that has a longer uncovered portion (5-15 mm) to prevent stent migration.. To estimate the efficacy and safety of the modified covered, triple-layer metal stent.. Multicenter, prospective cohort study.. Three tertiary referral centers.. Fifty consecutive patients (26 with pancreatic carcinoma, 14 with gastric carcinoma, 9 with cholangiocarcinoma, 1 with a metastatic node) who presented with symptomatic unresectable malignant GOO between April 2007 and March 2010.. Endoscopic placement of the modified covered, triple-layer metal stent.. The primary endpoint was to improve the GOO scoring system (GOOSS) score. Secondary endpoints were success rate, patency, and complications.. The median GOOSS score improved significantly (P < .0001) after stenting (from 0 to 3). The technical and clinical success rates were 100% and 90%, respectively. Stent occlusion by tumor overgrowth or ingrowth at the uncovered portion developed in 5 patients (10%). Asymptomatic stent migration occurred in 3 patients (6%) receiving chemotherapy at 95, 230, and 553 days after stent placement, but these patients tolerated solid food 68, 260, and 142 days after stent migration, respectively. Other complications occurred in 1 patient with insufficient expansion, cholangitis, and pancreatitis. No procedure-related deaths occurred.. A single-arm study in tertiary-care centers.. The modified covered, triple-layer metal stent was effective and safe for managing malignant GOO and can prevent tumor ingrowth and stent migration. (. UMIN000004566.).

Topics: Aged; Alloys; Bile Duct Neoplasms; Carcinoma; Cholangiocarcinoma; Female; Gastric Outlet Obstruction; Humans; Kaplan-Meier Estimate; Male; Middle Aged; Pancreatic Neoplasms; Prosthesis Failure; Stents; Stomach Neoplasms

Covered self-expandable metal stents (CSEMSs) were developed to prevent tumor ingrowth, but stent migration is one of the problems with CSEMSs.. To evaluate a new, commercially available CSEMS with flared ends and low axial force compared with a commercially available CSEMS without the anti-migration system and high axial force.. Multicenter, prospective study with a historical cohort.. Twenty Japanese referral centers.. This study involved patients with unresectable distal malignant biliary obstruction.. Placement of a new, commercially available, partially covered SEMS.. Recurrent biliary obstruction rate, time to recurrent biliary obstruction, stent-related complications, survival.. Between April 2009 and March 2010, 141 patients underwent partially covered nitinol stent placement, and between May 2001 and January 2007, 138 patients underwent placement of partially covered stainless stents as a historical control. The silicone cover of the partially covered nitinol stents prevented tumor ingrowth. There were no significant differences in survival (229 vs 219 days; P = .250) or the rate of recurrent biliary obstruction (33% vs 38%; P = .385) between partially covered nitinol stents and partially covered stainless stents. Stent migration was less frequent (8% vs 17%; P = .019), and time to recurrent biliary obstruction was significantly longer (373 vs 285 days; P = .007) with partially covered nitinol stents. Stent removal was successful in 26 of 27 patients (96%).. Nonrandomized, controlled trial.. Partially covered nitinol stents with an anti-migration system and less axial force demonstrated longer time to recurrent biliary obstruction with no tumor ingrowth and less stent migration.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Bile Duct Neoplasms; Cholestasis; Device Removal; Female; Gallbladder Neoplasms; Humans; Kaplan-Meier Estimate; Male; Middle Aged; Pancreatic Neoplasms; Proportional Hazards Models; Prosthesis Design; Prosthesis Failure; Recurrence; Silicones; Stainless Steel; Stents; Time Factors

Covered self-expanding metal stents (SEMSs) have proven effective for managing malignant bile duct strictures and may reduce risk of tumor ingrowth. A new nitinol partially covered biliary SEMS was prospectively evaluated.. 70 patients with inoperable extrahepatic biliary obstructions were enrolled in a prospective multicenter trial, and followed up to 6 months or death, whichever came first. Primary endpoint was adequate palliation defined as absence of recurrent biliary obstruction from partly covered SEMS placement to end of follow-up.. Mean age of the patients was 69 years and 52 % were men. Pancreatic carcinoma was present in 68 %. One stent was placed in 67 patients, two patients received two, and in one patient a guide wire could not traverse the stricture. In 55 % of patients the SEMS was inserted de novo and in 45 % for exchange with a plastic stent. Technical success was 97 %. At 6 months, 62 % of patients were free of obstructive symptoms; compared with baseline the mean number of symptoms per patient was significantly reduced (3.1 at baseline, 0.6 at 6 months; P < 0.0001) and total bilirubin levels dropped by 73 %. There were four cases of recurrent biliary obstruction, due to stent migration (2), tumor overgrowth (1), and sludge formation (1). Device-related complications included cholecystitis (3), right upper quadrant pain (1), and moderate pancreatitis (1). No tumor ingrowth was reported.. This new partially covered nitinol SEMS is easily inserted, and safe and effective in the palliation of biliary obstruction secondary to malignant bile duct strictures.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Bile Duct Neoplasms; Cholestasis, Extrahepatic; Coated Materials, Biocompatible; Common Bile Duct Diseases; Female; Humans; Male; Middle Aged; Palliative Care; Stents

The Wallstent has remained the industry standard for biliary self-expanding metal stents (SEMSs). Recently, stents of differing designs, compositions, and diameters have been developed.. To compare the new nitinol 6-mm and 10-mm Zilver stents with the 10-mm stainless steel Wallstent and determine the mechanism of obstruction.. Randomized, prospective, controlled study.. Nine centers experienced in SEMS placement during ERCP.. A total of 241 patients presenting between September 2003 and December 2005 with unresectable malignant biliary strictures at least 2 cm distal to the bifurcation.. Stent occlusions requiring reintervention and death.. At interim analysis, a significant increase in occlusions was noted in the 6-mm Zilver group at the P = .04 level, resulting in arm closure but continued follow-up. Final study arms were 64, 88, and 89 patients receiving a 6-mm Zilver, 10-mm Zilver, and 10-mm Wallstent, respectively. Stent occlusions occurred in 25 (39.1%) of the patients in the 6-mm Zilver arm, 21 (23.9%) of the patients in the 10-mm Zilver arm, and 19 (21.4%) of the patients in the 10-mm Wallstent arm (P = .02). The mean number of days of stent patency were 142.9, 185.8, and 186.7, respectively (P = .057). No differences were noted in secondary endpoints, and the study was ended at the 95% censored study endpoints. Biopsy specimens of ingrowth occlusive tissue revealed that 56% were caused by benign epithelial hyperplasia.. SEMS occlusions were much more frequent with a 6-mm diameter SEMS and equivalent in the two 10-mm arms despite major differences in stent design, material, and expansion, suggesting that diameter is the critical feature. Malignant tumor ingrowth produced only a minority of the documented occlusions.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Bile Duct Neoplasms; Catheterization; Cholangiopancreatography, Endoscopic Retrograde; Cholestasis; Female; Humans; International Cooperation; Kaplan-Meier Estimate; Male; Middle Aged; Neoplasm Staging; Palliative Care; Patient Selection; Probability; Prognosis; Prospective Studies; Prosthesis Design; Prosthesis Failure; Quality of Life; Risk Assessment; Stainless Steel; Stents; Survival Analysis; Terminally Ill; Treatment Outcome

Topics: Alloys; Bile Duct Neoplasms; Cholestasis; Endoscopy; Humans; Palliative Care; Stents

Curative resection of pancreatic and biliary malignancies is rare. Most tumors are inoperable at presentation, and palliation of jaundice often is the goal. Biliary decompression can be achieved by surgical diversion or endoscopic biliary stents. This study aimed to compare clinical outcomes between surgical bypass and endoscopic uncovered nitinol stents in the palliation of patients with malignant distal common bile duct obstruction.. A multicenter, retrospective, cohort study investigated 86 patients with inoperable malignant distal common bile duct strictures at tertiary referral centers in Medellín, Colombia. These patients had undergone surgery (group 1) or placement of an uncovered 30-Fr self-expandable nitinol stent produced locally in Medellín, Colombia (group 2). The main outcome measurements included cumulative biliary patency, hospital stay, and patient survival.. The study enrolled 86 patients (mean age, 66 years; range, 43-78 years) including 40 patients in group 1 and 46 patients in group 2. Both groups were similar in terms of age, gender, liver metastasis, and diagnosis. Technical success was achieved for 38 patients in group 1 (95%) and 43 patients in group 2 (93%). Functional biliary decompression was obtained in for 35 of the surgical patients (88%) and 42 of the stented patients (91%). Group 2 had lower rates for procedure-related mortality (2 vs. 7.5%; p = 0.01), a lower frequency of early complications (8.7 vs. 45%; p = 0.02), and a shorter hospital stay (median, 6 vs. 12 days; p = 0.01). Recurrent jaundice occurred for three patients in group 1 (7.5%) and eight patients in group 2 (17.3%) (p = 0.198). Late gastric outlet obstruction occurred for 12.5% of the patients in group 1 and 13% of the patients in group 2 (p = 0.73). Despite the early benefits of stenting, no significant difference in the median overall survival between the two groups was found (group 1, 163 days; group 2, 178 days; p = 0.11). The limitations of this study included the small number of patients and the retrospective design.. Endoscopic stenting and surgery are effective palliation. The former is associated with fewer early complications and the latter with fewer late complications. Patients who do not qualify for curative resection may be better managed by stent placement. Surgery should be reserved for patients more likely to survive longer.

Topics: Adult; Aged; Alloys; Bile Duct Neoplasms; Chi-Square Distribution; Cholestasis; Decompression, Surgical; Digestive System Surgical Procedures; Drainage; Female; Humans; Male; Middle Aged; Palliative Care; Retrospective Studies; Statistics, Nonparametric; Stents; Treatment Outcome

Nitinol self-expanding stents were used in treatment of 15 patients with blastomatous lesions of biliopancreatoduodenal zone. Stenting was successful in all cases, long-term results were obtained in all patients. Death occurred in 8 patients within 5,5-11 month after stent insertion. 7 patients remain under observation. In 6 patients nitinol stents remain open with no signs of occlusion from 2,5 to 15 months' observation period. Jaundice recurred in one patient after 11 month after the insertion due to stent occlusion. Thus, stenting proved to be an effective and safe method of bile flow restoration by tumor biliary tract obstruction.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Bile Duct Neoplasms; Duodenal Neoplasms; Endoscopy, Digestive System; Female; Humans; Jaundice, Obstructive; Male; Middle Aged; Pancreatic Neoplasms; Prosthesis Design; Stents; Treatment Outcome

A 6F endoscopic biliary self-expanding metal stent (SEMS) has been newly introduced for intended simultaneous side-by-side bilateral deployment in hilar malignant obstruction.. To report our initial experience with the Zilver 635 biliary SEMS.. Retrospective chart review.. Tertiary referral medical center.. Sixteen consecutive malignant hilar biliary obstruction patients.. Endoscopic palliative treatment of malignant biliary obstruction with the Zilver 635 SEMS from December 2008 to January 2010.. Technical/functional success rates, early complications (within 30 days of stent placement), early/late stent occlusion, and biliary reintervention rates.. A total of 49 Zilver SEMSs were placed in 16 patients (mean age 61 years, 6 men) for Bismuth type II (n = 4), III (n = 5), and IV (n = 7) lesions. Twelve had cholangiocarcinoma, 2 had metastatic colon cancer, 1 had lung cancer, and 1 had pancreatic cancer. The technical success rate was 100%. Side-by-side simultaneous bilateral stent deployment was required and was achieved successfully in 10 cases. Additional transpapillary stents were placed for potential future biliary access. The 30-day mortality rate was 0%. There were 1 early (6%) and 3 late (19%) stent occlusions. Successful overall biliary drainage was 75%.. Small sample size, uncontrolled retrospective study.. Malignant hilar biliary obstruction endoscopic palliation with the Zilver 635 SEMS offers acceptable initial feasibility, safety, and efficacy profiles. The current design facilitates smaller bile duct negotiation and more precise intrahepatic placement. Expanding available lengths would allow transpapillary bridged bilateral SEMS placement for future reobstructed biliary access. Further long-term studies are required for comparative outcomes with other current SEMS technology.

Topics: Adult; Aged; Alloys; Bile Duct Neoplasms; Cholangiocarcinoma; Cholangiopancreatography, Endoscopic Retrograde; Cholestasis, Intrahepatic; Colonic Neoplasms; Duodenoscopes; Equipment Design; Female; Follow-Up Studies; Humans; Liver Neoplasms; Male; Middle Aged; Palliative Care; Retrospective Studies; Stents

Self-expanding metallic stents are widely used for relieving biliary duct obstruction in patients with unresectable periampullary malignancies. However, only a few studies have assessed the occurrence of fractures in these stents.. To determine the prevalence and significance of stent fracture after placement of self-expanding metallic stents for periampullary malignant biliary obstruction.. Over a 5-year period, 48 patients underwent placement of self-expanding metallic stents for periampullary malignant biliary obstructions. Stents were introduced 2-6 weeks after a percutaneous transhepatic biliary decompression. The medical records and relevant images were reviewed for stent patency, stent fracture, type of stent, and stent-related complications.. Stent fracture was detected in four of the 48 patients (8%): in one patient at 1 month and in three patients between 10 and 21 months after stenting. All four fractures involved one type of nitinol stent used in 38 patients. In one of the patients, fracture was complicated by life-threatening gastrointestinal bleeding. The mean survival time for all patients was 251 days (standard deviation [SD]+/-275 days) and the mean overall patency time for all stents was 187 days (SD+/-205 days).. Stent fracture occurs after placement of self-expanding nitinol stents for periampullary malignant biliary obstruction. The low reported incidence of this complication may be due to a lack of awareness of and difficulty in detecting stent fracture. Fracture should be considered as a possible contributing factor in recurrent biliary obstruction after self-expanding metallic stent insertion.

Topics: Aged; Aged, 80 and over; Alloys; Bile Duct Neoplasms; Cholangiography; Cholestasis; Fatal Outcome; Female; Humans; Male; Middle Aged; Pancreatic Neoplasms; Prosthesis Failure; Stents

Malignant biliary obstruction may be caused by cholangiocarcinoma and other nonbiliary carcinomas. At the time of diagnosis, 90% of patients with malignant obstructive jaundice may benefit from palliative treatment only. The objective of palliation is to relieve jaundice-related symptoms, prevent cholangitis, prolong survival, and improve quality of life. Percutaneous transhepatic biliary stenting is a well-established procedure used in patients with malignant obstruction of intra- and extrahepatic bile ducts. Twelve patients (9 women, 3 men; mean age, 68 years; range, 44-88 years) with inoperable malignant biliary obstruction were selected for percutaneous transhepatic biliary stenting with metallic stents in the period from January to December 2007. Technical and clinical success rate in this patient series was 83% and 80%, respectively. Minor and major complications occurred in 17% and 8% of cases, respectively, which is in the range reported by the others. This is our first experience of percutaneous transhepatic biliary stenting at the Hospital of Kaunas University of Medicine and, to our knowledge, the first reported patient series in Lithuania. These first results encourage expanding effective palliation by the employment of the percutaneous transhepatic biliary stenting in patients with nonresectable malignant biliary obstruction or in case of a recurrent disease after curative surgery. The cost effectiveness of percutaneous transhepatic biliary stenting against percutaneous transhepatic biliary drainage has yet to be evaluated in a prospective manner. However, immediate clinical benefits and positive short-term outcomes are unequivocal.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Cholangiocarcinoma; Cholestasis; Drainage; Endoscopy; Female; Follow-Up Studies; Gallbladder Neoplasms; Humans; Jaundice, Obstructive; Male; Middle Aged; Palliative Care; Pancreatic Neoplasms; Patient Selection; Postoperative Complications; Quality of Life; Radiography; Stainless Steel; Stents; Time Factors; Treatment Outcome

For the treatment of unresectable biliary tract carcinoma with hilar biliary stricture, antitumor therapy and biliary stenting should be addressed in terms of prolonged survival with a good quality of life. However, the endoscopic management of malignant hilar biliary strictures is difficult even for an expert endoscopist. We evaluated the efficacy and safety of the endoscopic deployment of multiple JOSTENT SelfX units in patients with hilar biliary strictures treated with or without chemotherapy.. Between November 2003 and December 2006, endoscopic deployment of multiple JOSTENT SelfX units in hilar biliary strictures by using a partial stent-in-stent procedure was performed on 41 consecutive patients with primary cholangiocarcinoma (n = 34) and gallbladder carcinoma (n = 7) at a gastroenterologic center of Okayama University Hospital. Thirty-three patients were treated with gemcitabine (n = 25) or S-1 (n = 8).. Metallic stent deployment was successfully accomplished in all cases via only endoscopic procedures. During the follow-up period (mean, 210 days), mean patency time was 150 days, and metallic stent obstruction occurred in 15 cases (37%). Although a repeat intervention was required in all metallic stent obstructed cases, the deployment of the second metallic or plastic stent was completed successfully. The remaining 26 cases (63%) required no interventions. The median overall survival period was only 235 days. However, that of the patients receiving chemotherapy was 392 days.. Endoscopic partial stent-in-stent deployment with multiple JOSTENT SelfX prostheses is effective and safe for the treatment of malignant hilar biliary stricture even in patients receiving chemotherapy.

Topics: Aged; Aged, 80 and over; Alloys; Antineoplastic Agents; Bile Duct Neoplasms; Cholangiocarcinoma; Cholestasis; Endoscopy, Digestive System; Feasibility Studies; Female; Gallbladder Neoplasms; Humans; Male; Middle Aged; Prosthesis Implantation; Reoperation; Retrospective Studies; Stents; Treatment Outcome

Although endoscopic stent placement is now generally accepted as a palliative method of treatment in unresectable hilar cholangiocarcinoma, exclusively endoscopic placement of bilateral metal stents has been considered very difficult and complex.. To evaluate the technical and clinical efficacy of endoscopic placement of dual, newly designed stents in a Y configuration.. Prospective, uncontrolled, single center.. Tertiary referral university hospital.. Ten patients with unresectable hilar cholangiocarcinoma of Bismuth type II or higher.. For bilateral metal stent placement, a biliary Y stent with central wide-open mesh was used exclusively at first. A second stent was placed into the contralateral hepatic duct through the central open mesh of the Y stent.. Technical success, functional success, early complications, and short-term clinical outcome.. Technical success was achieved in 8 of 10 patients (80%). Among 8 patients in whom bilateral stents were successfully placed by endoscopy, functional success was 100%, the early complication rate was 0%, and the stent occlusion rate was 25%. The median stent patency period was 217 days.. Small number of patients, uncontrolled study, short-term follow-up period.. We described a technique for endoscopic bilateral metal stent placement by using the newly designed Y stent for advanced hilar cholangiocarcinoma that resulted in a high success rate of 80%.

Topics: Aged; Alloys; Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Cholangiocarcinoma; Cholestasis; Drainage; Endoscopy, Digestive System; Female; Hepatic Duct, Common; Humans; Male; Middle Aged; Palliative Care; Stents

Topics: Aged; Alloys; Bile Duct Neoplasms; Cholestasis, Extrahepatic; Fatal Outcome; Follow-Up Studies; Foreign-Body Migration; Hepatic Duct, Common; Hernia, Inguinal; Humans; Intestinal Obstruction; Intestine, Small; Male; Prosthesis Failure; Radiography; Reoperation; Rupture; Stents

Topics: Alloys; Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Biliary Fistula; Cholangiocarcinoma; Common Bile Duct Diseases; Humans; Male; Middle Aged; Postoperative Complications; Stents

To evaluate the clinical usefulness of a new nitinol biliary stent (Memotherm) in patients with malignant biliary obstruction. 32 self expanding nitinol stents were applied in 17 patients. The following parameters were investigated: Difficulty of placement, lateral stability and patency over an observation time between 3 weeks and 11 months.. In 29/32 stent application could be performed with high precision. In 3/32 we observed a displacement about 1 cm--according to the optimal stent position. Stent shortening was about 5 mm in 31/32 stents, secondary shortening only occurred in one patient with primarily distracted stent design. Lateral stability was sufficient in 21/25 stenoses with the consequence that dilatation was only performed in 4 cases. Average stent patency was 4.8 months, the average survival 5.1 months. Because of his special design, this stent may not be used for a stenosis with angulation higher than 90 degrees.. Basing on a small calibre introducing system, easy placement, predictable minimal shortening and good lateral stability, the Memotherm seems an interesting alternative to other metal stents.

Topics: Alloys; Bile Duct Neoplasms; Cholestasis; Drainage; Evaluation Studies as Topic; Female; Humans; Male; Radiography; Stents

The nitinol stent is a self-expandable spiral stent made of nickel-titanium alloy. We performed a pilot study to evaluate the method of stent insertion and stent efficacy.. Twenty-eight patients with irresectable malignancy had nitinol stents inserted for obstructive jaundice due to distal biliary strictures. They were followed prospectively for a median of ten weeks (range 1-48) until stent occlusion or death. All patients underwent sphincterotomy prior to stent insertion. Stent deployment was assisted by subsequent balloon dilation of the stent in two patients. Plastic stent insertion was used to temporarily brace the nitinol stent in another three patients.. Short-term relief of jaundice was achieved in 20 of the 28 patients (71%). The remaining eight patients had persistent jaundice due to failure of stent insertion (three patients) or early stent dysfunction (five patients). Long-term success was achieved in 12 of 28 patients (43%). Ten of the 12 patients died without complications after a median of 13.5 weeks (range 3-48). One of the 12 patients is still alive with the stent in place for 40 weeks, and one patient underwent elective bypass surgery, and the stent was removed surgically. Eight of the 28 patients had recurrent symptoms due to late stent dysfunction after a median of 19 weeks (range 6-32).. Nitinol stents are technically difficult to insert. The problem of stent dysfunction (13 of 28, 46%) is not improved by the use of nitinol stents. Whether improvement of the insertion technique and enhancement of the expanding force of the stent may improve stent efficacy merits further evaluation.

Topics: Aged; Aged, 80 and over; Alloys; Bile Duct Neoplasms; Cholestasis, Extrahepatic; Combined Modality Therapy; Common Bile Duct Neoplasms; Female; Follow-Up Studies; Humans; Male; Middle Aged; Pilot Projects; Prospective Studies; Prosthesis Failure; Sphincterotomy, Endoscopic; Stents; Treatment Outcome