Covered self-expanding transhepatic biliary stents: clinical pilot study

Uncovered versus fully covered self-expandable metal stents for the management of distal malignant biliary obstruction

BACKGROUND AND AIM

Self-expandable metal stents (SEMSs) are widely used for palliation of distal malignant biliary obstruction (dMBO). However, previous studies comparing the outcomes between uncovered SEMSs (UCSEMSs) and fully covered SEMSs (FCSEMSs) report conflicting results. This large cohort study aimed to compare the clinical outcomes between UCSEMSs and FCSEMSs for dMBO.

METHODS

A retrospective cohort study was performed in patients with dMBO who underwent either UCSEMS or FCSEMS placement between May 2017 and May 2021. Primary outcomes were rates of clinical success, adverse events (AEs), and unplanned endoscopic reintervention. Secondary outcomes were types of AEs, intervention-free stent patency, and management and outcomes of stent occlusion.

RESULTS

The cohort included 454 patients (364 in the UCSEMS group and 90 in the FCSEMS group). Median follow-up duration was 9.6 months and was similar between the 2 groups. Use of UCSEMSs and FCSEMSs had comparable clinical success (P = .250). However, use of UCSEMSs had significantly higher rates of AEs (33.5% vs 21.1%; P = .023) and unplanned endoscopic reintervention (27.0% vs 11.1%; P = .002). UCSEMSs had a higher rate of stent occlusion (26.9% vs 8.9%; P < .001) and shorter median time to stent occlusion (4.4 months vs 10.7 months; P = .002). Stent reintervention-free survival was higher in the FCSEMS group. FCSEMSs had a significantly higher rate of stent migration (7.8% vs 1.1%; P < .001), but patients in the FCSEMS group had similar rates of cholecystitis (.3% vs 1.1%; P = .872) and post-ERCP pancreatitis (6.3% vs 6.6%; P = .90). When UCSEMSs did occlude, placement of a coaxial plastic stent had a higher rate of stent reocclusion compared with coaxial SEMS placement (46.7% vs 19.7%; P = .007).

CONCLUSION

FCSEMSs should be considered for the palliation of dMBO because of lower rates of AEs, longer patency rates, and lower rates of unplanned endoscopic intervention.

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

Objective

To investigate the technical safety and clinical efficacy of a double-stent system with long duodenal extension in patients with malignant extrahepatic biliary obstruction.

Materials and Methods

This prospective study enrolled 48 consecutive patients (31 men, 17 women; mean age, 61 years; age range, 31–77 years) with malignant extrahepatic biliary obstructions from May 2013 to December 2015. All patients were treated with a double-stent system with long duodenal covered extension (16 cm or 21 cm).

Results

The stents were successfully placed in all 48 patients. There were five (10.4%) procedure-related complications. Minor complications were self-limiting hemobilia (n = 2). Major complications included acute pancreatitis (n = 1) and acute cholecystitis (n = 2). Successful internal drainage was achieved in 42 (87.5%) patients. Median patient survival and stent patency times were 92 days (95% confidence interval [CI], 61–123 days) and 83 days (95% CI, 46–120 days), respectively. Ten (23.8%) of the 42 patients presented with stent occlusion due to food impaction with biliary sludge, and required repeat intervention. Stent occlusion was more frequent in metastatic gastric cancer patients with pervious gastrectomy, but did not reach statistical significance (p = 0.069).

Conclusion

Percutaneous placement of a double-stent system with long duodenal extension is feasible and safe. However, this stent system does not completely prevent stent occlusion caused by food reflux.

A prospective, multicenter study of a double stent system for palliative treatment of malignant extrahepatic biliary obstructions

BACKGROUND

A double stent system (covered stent in uncovered stent) was designed to provide long-term patency without tumor ingrowth or stent-related complications, such as stent migration, cholecystitis, or pancreatitis.

PURPOSE

To investigate the safety and efficacy of double stents in patients with malignant extrahepatic biliary obstructions.

MATERIAL AND METHODS

This prospective, nonrandomized, multicenter study enrolled 160 consecutive patients (102 men; mean age, 64 years; range, 33-91 years) with malignant extrahepatic biliary obstructions treated with a double stent system from January 2010 to March 2012.

RESULTS

The technical success rate of the double stent placement was 100%. No stent migration was observed. Procedure-related minor (self-limiting hemobilia [n = 6] and cholangitis [n = 2]) and major (pancreatitis [n = 16], cholecystitis [n = 3], and hepatic abscess [n = 2]) complications occurred in a total of 29 patients. The mean serum bilirubin level, which was 8.9 ± 5.6 mg/dL before drainage, decreased to 2.2 ± 4.6 mg/dL 1 month after stent placement (P < 0.001). Successful internal drainage was achieved in 148 patients (92.5%). During the mean follow-up period of 205 days, acute cholecystitis (n = 3) and hepatic abscess (n = 2) occurred in five patients. The median patient survival and stent patency time were 135 days (95% confidence interval [CI], 96-160 days) and 114 days (95% CI, 83-131 days), respectively. Of 153 patients, 22 (14.4%) presented with stent dysfunction due to sludge incrustation (n = 17), tumor overgrowth (n = 4), or blood clot (n = 1), and required repeat intervention. Tumor ingrowth was not observed in any of these patients.

CONCLUSION

Percutaneous treatment of malignant extrahepatic biliary obstruction using a double stent safely and effectively achieves internal biliary drainage.

An Update to Hepatobiliary Stents

Endoscopic stent placement is a common primary management therapy for benign and malignant biliary strictures. However, continuous use of stents is limited by occlusion and migration. Stent technology has evolved significantly over the past two decades to reduce these problems. The purpose of this article is to review current guidelines in managing malignant and benign biliary obstructions, current endoscopic techniques for stent placement, and emerging stent technology. What began as a simple plastic stent technology has evolved significantly to include uncovered, partially covered, and fully covered self-expanding metal stents (SEMS) as well as magnetic, bioabsorbable, drug-eluting, and antireflux stents.(1).

Paclitaxel-eluting nanofiber-covered self-expanding nonvascular stent for palliative chemotherapy of gastrointestinal cancer and its related stenosis

Self-expanding non-vascular metal stents (SEMS) is now a choice of treatment for tumor-induced obstructive symptoms of gastrointestinal tract. But in-growing tumor causes re-stenosis. Here, we studied a paclitaxel-eluting nanofiber-covered stent for palliative chemotherapy of gastrointestinal cancer and its related stenosis. In vivo and in vitro feasibility of nanofiber-covered nonvascular stent was evaluated in this study. Nanofiber-covered stent released paclitaxel (PTX) in controlled manner for 30 days. PTX-NFM significantly inhibited the growth of CT-26 colon cancer in comparison with PTX injection. PTX maintained higher tumor concentrations over 1.0 μg/ml for more than 14 days without systemic exposure. TUNEL and H&E staining proved locally concentrated PTX induced the higher apoptosis than PTX injection. In this way, PTX-eluting nanofiber-covered stent possibly inhibits in-growth of cancer and extends patency of stent. Clinical feasibility of PTX-eluting nanofiber nonvascular stent for cholangiocarcinoma and gastrointestinal cancers will be investigated in further studies.

Percutaneous use of ePTFE/FEP-covered metallic stent for palliation of malignant biliary obstruction

INTRODUCTION

Placement of self-expanding metallic stents has been a standard palliative treatment for patients with inoperable biliary malignancy, aiming at improving quality of life via a minimally invasive procedure. This study aimed to evaluate the efficacy of percutaneous placement of expanded polytetrafluoroethylene/fluorinated ethylene propylene-covered metallic stents for palliation of inoperable biliary malignancy.

MATERIAL AND METHODS

Between February 2012 and April 2013, 11 patients with inoperable malignant biliary obstruction were treated with stent implantation. Serum bilirubin and liver enzyme levels were measured before/immediately after stent placement and at one, three, and six months. Patient survival and stent patency were calculated using Kaplan-Meier analysis.

RESULTS

No migration occurred. Patients showed clinical improvement immediately and one month after stent placement, with a significant reduction in mean serum bilirubin level (p < 0.05). At six months, bilirubin levels were <1.5 mg/dL in all cases. One patient developed acute liver failure four days after stent implantation, leading to death. Survival rates were 90% at three months and 70% at six months. Primary patency rates were 100%, 100%, and 90% at one, three, and six months, respectively.

CONCLUSION

Percutaneous placement of expanded polytetrafluoroethylene/fluorinated ethylene propylene-covered metallic stents offered an effective palliative therapy for patients with inoperable biliary malignancy.

Endoscopic sphincterotomy associated cholangitis in patients receiving proximal biliary self-expanding metal stents

BACKGROUND

Endoscopic biliary stent placement during the procedure of endoscopic retrograde cholangiopancreatography (ERCP) is preferred to provide biliary drainage for unresectable malignant biliary obstruction. There is considerable controversy over the use of endoscopic sphincterotomy (ES) prior to stent placement. This study aimed to determine whether ES before intraductal self-expanding metal stent (SEMS) placement affects the clinical outcome and complications in patients with proximal malignant obstructive biliary diseases.

METHODS

In a prospective randomized controlled trial, 82 patients with inoperable malignant biliary strictures were randomly assigned to biliary stenting groups with or without ES. Resolution of jaundice and the incidence of complications including acute cholangitis, pancreatitis and stent occlusion within 6 months were evaluated.

RESULTS

SEMSs were successfully deployed in all patients, resulting in clinical and biochemical improvement of obstructive symptoms in both groups. The incidence of cholangitis was higher in the ES group than in the non-ES group (58.5% vs 31.7%, P=0.015). The interval between stent placement and the first acute cholangitis was much shorter in the ES group than in the non-ES group (P=0.024). The use of ES increased the incidence of cholangitis (P=0.004, risk ratio, 8.196). The rate of post-ERCP pancreatitis after stent placement was greater in the non-ES group than in the ES group (31.7% vs 9.8%, P=0.014). No significant differences were found in the rate of restenosis and the mortality rate between the two groups.

CONCLUSIONS

ES prior to intraductal SEMS placement was associated with an increased incidence of acute cholangitis. ES should be carefully evaluated prior to its use in patients with proximal malignant obstructive biliary diseases.

Cefotaxime-eluting covered self-expandable stents in a canine biliary model: scanning electron microscopic study of biofilm formation

BACKGROUND

As bacterial attachment and subsequent biofilm formation on the surface of a stent lumen may be important in initiating sludge formation and subsequent stent blockage, there is a need for antibiotic-eluting stents to prevent sludge formation by bacterial attachment and colonization.

PURPOSE

To evaluate the antimicrobial effects of cefotaxime-eluting covered self-expandable stents (CE-CSEMS) in a canine biliary model by using scanning electron microscopy (SEM) to analyze biofilm formation on the inner surface of the stents.

MATERIAL AND METHODS

Three 10% (wt/vol) CE-CSEMS, three 20% (wt/vol) CE-CSEMS, and three control stents (CS) were endoscopically inserted into the bile ducts of nine mongrel dogs, which were followed up for 8 weeks. Gross and SEM examinations were performed to access the development and degree of biofilm formation in dogs with CS and CE-CSEMS.

RESULTS

All stents were successfully inserted into canine bile ducts without any procedure-related complications. All nine dogs remained in good health without jaundice over the next 8 weeks. The degree of biofilm was similar in dogs implanted with CS and CE-CSEMS using two concentrations of cefotaxime either by gross inspection or SEM. All stent types showed a similar biofilm structure with relatively uniform thickness on SEM.

CONCLUSION

Cefotaxime does not prevent biofilm development in a canine biliary model. Biofilm formation on the inner surface of biliary stents may be prevented by using broad-spectrum antimicrobial agents and stents that maintain a steady release of these agents for a long time, thus prolonging stent patency.

A comparative study on the efficacy of covered metal stent and plastic stent in unresectable malignant biliary obstruction

Background/Aims

The placement of self expandable metal stent (SEMS) is one of the palliative therapeutic options for patients with unresectable malignant biliary obstruction. The aim of this study was to compare the effectiveness of a covered SEMS versus the conventional plastic stent.

Methods

We retrospectively evaluated 44 patients with unresectable malignant biliary obstruction who were treated with a covered SEMS (21 patients) or a plastic stent (10 Fr, 23 patients). We analyzed the technical success rate, functional success rate, early complications, late complications, stent patency and survival rate.

Results

There was one case in the covered SEMS group that had failed technically, but was corrected successfully using lasso. Functional success rates were 90.5% in the covered SEMS group and 91.3% in the plastic stent group. There was no difference in early complications between the two groups. Median patency of the stent was significantly prolonged in patients who had a covered SEMS (233.6 days) compared with those who had a plastic stent (94.6 days) (p=0.006). During the follow-up period, stent occlusion occurred in 11 patients of the covered SEMS group. Mean survival showed no significant difference between the two groups (covered SEMS group, 236.9 days; plastic stent group, 222.3 days; p=0.182).

Conclusions

The patency of the covered SEMS was longer than that of the plastic stent and the lasso of the covered SEMS was available for repositioning of the stent.

Gemcitabine-releasing polymeric films for covered self-expandable metallic stent in treatment of gastrointestinal cancer

Non-vascular drug-eluting stents have been studied for the treatment of gastrointestinal cancer and cancer-related stenosis. In this study, we designed and evaluated a gemcitabine (GEM)-eluting covered nonvascular stent. Polyurethane (PU)/polytetrafluoroethylene (PTFE) film was selected for the drug loading and eluting membrane. The membrane was fabricated by dip-coating on a Teflon bar (∅; 10mm), air-dried, peeled off and applied to a self-expanding Nitinol stent. Various amounts of poloxamer 407 (PL, Lutrol F127, BASF) (8%, 10%, or 12% of PU by weight) were added to control the release of GEM from membranes. The membrane containing 12% PL (GEM-PU-PL12%) showed the most favourable release properties; 70% of the loaded GEM released within 35 days, including the 35% released during the initial burst. The biological activities of GEM-PU-PL12% were evaluated using human cholangiocarcinoma cells (SK-ChA-1). GEM-PU-PL12% most efficiently inhibited the proliferation of cholangiocarcinoma cells and most highly induced pro-inflammatory cytokines (TNF-α, IL-1β and IL-12) and p38 MAPKs in the cells. Subtumoural insertion of the GEM-PU-PL12% membrane more efficiently inhibited the growth of CT-26 colon cancer than other membranes. In this study, the GEM-eluting metal stents covered with PU-PL12% showed considerable feasibility for the treatment of malignant gastrointestinal cancer as well as cancer-related stenosis.

A novel double stent system for palliative treatment of malignant extrahepatic biliary obstructions: a pilot study

OBJECTIVE

The purpose of this study is to investigate the efficacy and safety of a novel double stent in patients with malignant extrahepatic biliary obstruction.

SUBJECTS AND METHODS

This prospective pilot study enrolled 45 consecutive patients with malignant extrahepatic biliary obstructions from January 2008 to December 2009. All patients were treated with a novel double stent system (covered stent in uncovered stent).

RESULTS

The double stents were successfully placed in all patients. Bilirubin levels decreased significantly after stent placement (p < 0.001). Median patient survival and stent patency times were 149 days (95% CI, 126-172 days) and 439 days (95% CI, 123-755 days), respectively. Cumulative stent patency rates at 3, 6, 9, and 12 months were 91%, 89%, 82%, and 82%, respectively. Five patients (11.1%) presented with stent occlusion due to tumor overgrowth (n = 3) or sludge incrustation (n = 2) and required repeat intervention. Tumor ingrowth, acute cholecystitis, pancreatitis, or stent migration was not observed in any of these patients.

CONCLUSION

Preliminary results indicate that percutaneous treatment of malignant extrahepatic biliary obstructions using a novel double stent is feasible, safe, and effective in achieving internal biliary drainage.

Biliary stents in the millennium

Biliary stents have now been in use for over two decades. Although a plethora of literature has been published on them, this review article is unique in its attempt to summarize important landmark trials and their implications on the management of various pancreatico-biliary disorders. This article will cover the various types of stents currently being used, established and upcoming indications, techniques of placement, and complications associated with stent use.

An acetylated polysaccharide-PTFE membrane-covered stent for the delivery of gemcitabine for treatment of gastrointestinal cancer and related stenosis

Gemcitabine (Gem) eluting metal stents were prepared for potential application as drug delivery systems for localized treatment of malignant tumors. Pullulan, a natural polysaccharide, was chemically acetylated (pullulan acetate; PA) by different degrees (1.18, 1.71, and 2.10 acetyl groups per glucose unit of pullulan), layered on polytetrafluoroethylene (PTFE), and applied as part of a Gem-loaded controlled-release membrane for drug-eluting non-vascular stents. PA with a higher degree of acetylation had greater drug-loading capacity with more extended release of Gem over 30 days. The released Gem accumulated in CT-26 colon cancer without systemic exposure inducing total regression of tumors. The long-term biological activity of the released Gem and apoptosis of tumor tissues following localized delivery were confirmed by annexin V binding assays and histology. The controlled release of Gem from PA-PTFE covered drug-eluting stents (DES) may increase the patency of these stents for the treatment of malignant gastrointestinal cancer as well as cancer-related stenosis.

Endoscopic biliary sphincterotomy is not required for transpapillary SEMS placement for biliary obstruction

BACKGROUND

Endoscopic retrograde cholangiopancreatography with biliary self-expanding metal stent placement is the preferred method of providing biliary drainage for pancreaticobiliary malignancies. Some endoscopists routinely perform biliary sphincterotomy to facilitate biliary stent placement and potentially minimize pancreatitis with transpapillary self-expanding metal stent placement.

AIMS

Our hypothesis was that biliary sphincterotomy has no effect on the success rate of transpapillary self-expanding metal stent placement and increases procedure-related complications.

METHODS

In a retrospective analysis, outcomes of two groups were compared: (1) self-expanding metal stent placement without biliary sphincterotomy, (2) self-expanding metal stent placement with biliary sphincterotomy during the same procedure. Complications and stent patency rates were evaluated.

RESULTS

There were 104 subjects included in the study. Post-sphincterotomy bleeding (p = 0.001) was associated with biliary sphincterotomy performed immediately prior to self-expanding metal stent placement. Importantly, self-expanding metal stent placement without biliary sphincterotomy was always technically successful and self-expanding metal stent placement without biliary sphincterotomy was not associated with pancreatitis.

CONCLUSIONS

Patients who undergo biliary sphincterotomy during transpapillary self-expanding metal stent placement experience more immediate complications than those who do not. Biliary sphincterotomy was not associated with longer stent patency. Self-expanding metal stent placement without a biliary sphincterotomy was not associated with pancreatitis regardless of the type of self-expanding metal stent used (covered or uncovered). Of the patients without a biliary sphincterotomy, 100% had successful stent placement, further arguing against its use in this setting.

A comparative analysis of PTFE-covered and uncovered stents for palliative treatment of malignant extrahepatic biliary obstruction

OBJECTIVE

The purpose of our study was to evaluate the outcomes of the newly designed partially polytetrafluoroethylene (PTFE)-covered stent and compare the outcomes of PTFE-covered and uncovered stents in patients with malignant extrahepatic biliary obstruction.

MATERIALS AND METHODS

From March 2006 to December 2008, 58 consecutive patients who underwent PTFE-covered stent placement were prospectively studied. Those data were compared with data obtained by retrospectively studying 58 consecutive patients who underwent self-expanding uncovered stent placement from March 2003 to February 2006.

RESULTS

According to the Kaplan-Meier analysis, the cumulative stent patency of covered stents (98%, 98%, 91%, 76%, and 76% at 1, 3, 6, 9, and 12 months, respectively) was significantly better than that of uncovered stents (98%, 83%, 72%, 57%, and 57% at 1, 3, 6, 9, and 12 months, respectively) (p = 0.037). There was no significant difference in the patient survival between the groups (p = 0.479). The two groups also did not significantly differ in terms of complication rate (p = 0.717), with 8.6% (5/58) in the covered stent group and 5.2% (3/58) in the uncovered stent group.

CONCLUSION

Partially PTFE-covered stents are effective and safe for the palliative treatment of malignant extrahepatic biliary obstruction. Moreover, PTFE-covered stents were significantly superior to uncovered stents in terms of stent patency for palliative treatment of patients with malignant extrahepatic biliary obstruction. In addition, there was no significant difference in patient survival and complication rate between the PTFE-covered and uncovered stent group.

Prospective evaluation of a newly designed T-configured stent graft system for palliative treatment of advanced hilar malignant biliary obstructions

PURPOSE

To investigate the technical and clinical safety and efficacy of using a newly designed T-configured stent graft for palliative treatment of advanced hilar malignant biliary obstructions.

MATERIALS AND METHODS

This is a prospective study that enrolled 30 patients who had malignant hilar obstructions from May 2007 to November 2008. All patients were treated with percutaneous transhepatic placement of two specially designed stent grafts in a T configuration. Technical success, evaluation of blocked branching ducts, complications, clinical success, stent patency time, and patient survival rates were analyzed.

RESULTS

Stent graft deployment was technically successful in all patients. The bilirubin level and the bile duct diameter decreases were statistically significant after stent placement (P < .001), and all patients showed clinical improvement. Minor complications, including procedure-related complications (self-limiting hemobilia [n = 3], perihepatic biloma [n = 1], and acute pancreatitis [n = 1]) and rapidly resolving cholangitis (n = 5), occurred in ten patients (33.3%). Major complications, including acute cholecystitis, occurred in three patients (10%). Stent occlusion occurred in 12 patients (40%) after a mean period of 160 days (range, 82-307 days). The median survival and stent patency times were 334 days (range, 195.6-472.4 days) and 279 days (range, 194.7-363.3 days), respectively. There were no statistical differences in age, sex, Bismuth type, or number of blocked branching ducts.

CONCLUSIONS

The initial results of percutaneous palliative treatment of advanced hilar malignancies with T-configured stent grafts suggest that they are safe and potentially clinically effective.

Management of complications associated with partially covered biliary metal stents

BACKGROUND

Partially covered metal stents (PCMS) have been increasingly used for both malignant and benign biliary indications. This study reports their complications and subsequent management.

METHODS

Over 5 years, all patients receiving biliary PCMS were followed prospectively until stent-related dysfunction or death. Data were analyzed for the following variables: primary disease, time until revision, and type and reason for revision.

RESULTS

PCMS were placed in 396 patients (247 with malignant biliary strictures and 149 with benign biliary disease). Complications were observed in 70 patients (18%), occurring a mean time following placement of 159 days. Duodenal migration occurred in 27 cases (6.8%), while proximal migration occurred in 9 cases (2.3%). Cholecystitis was documented in 13 cases (3.3%). There were six cases of stent occlusion due to debris or sludge (1.6%), four cases of pancreatitis (1%), four cases of tumor overgrowth (1%), three cases of benign stenosis in the uncovered portion of the PCMS (0.8%), two cases of abdominal pain (0.5%), one case of an infected biloma (0.3%), and one case of a liver abscess (0.3%).

CONCLUSIONS

Major complications associated with PCMS placement include migration and cholecystitis. Their management includes endoscopic revision, cholecystectomy, and gallbladder drainage. Further improvements in the structure and composition of PCMS may prevent these complications.

Efficacy and safety of fully covered self-expandable metallic stents in biliary complications after liver transplantation: a preliminary study

After liver transplantation, the most common biliary complication is the anastomotic stricture, which is followed by biliary leakage. Studies have focused on the endoscopic treatment of biliary complications in transplanted patients with duct-to-duct reconstruction, showing a success rate of 70% to 80% after orthotopic liver transplantation and of 60% after living-related liver transplantation. Once the endoscopic approach fails, surgical treatment with a Roux-en-Y choledochojejunostomy is the sole alternative treatment. The aim of this prospective observational study was to analyze the efficacy and safety of fully covered self-expandable metallic stents for the treatment of posttransplant biliary stenosis and leaks in patients in whom conventional endoscopic retrograde cholangiopancreatography (ERCP) failed. From January 2008 to January 2009, 16 patients met the criteria of endoscopic treatment failure, and instead of surgery, a fully covered stent was placed. All patients had at least 6 months of follow-up (mean follow-up of 10 months). After removal, 14 patients showed immediate resolution of both the biliary stenosis and leak. After a mean of 10 months of follow-up, only 1 patient showed biliary stenosis recurrence. No major complications occurred in any of the patients, except for stent migration in 6 patients, although these presented with no clinical consequences. In conclusion, in patients not responding to standard endoscopic treatment, the placement of fully covered metal stents is a valid alternative to surgery. A cost analysis should be performed in order to evaluate whether to treat transplanted patients suffering from biliary complications with covered self-expandable metallic stent placement as first-line therapy.

Endoscopic sphincterotomy before deployment of covered metal stent is associated with greater complication rate: a prospective randomized control trial

OBJECTIVE

Endoscopic sphincterotomy (ES) may facilitate insertion of self expandable metal stent (SEMS) and also help avert the development of pancreatitis from stent-related occlusion of the pancreatic duct. On the other hand, ES is also independently associated with pancreatitis, bleeding, and perforation. We evaluated whether ES before SEMS placement was associated with a greater likelihood of stent migration and other complications in patients with malignant obstruction of the distal common bile duct.

METHODS

Seventy-four patients with unresectable distal bile duct obstruction were prospectively randomized to biliary stenting following ES (group 1) and without ES (group 2). Main outcome measures included overall procedure complications rates including stent migration, stent occlusion, oxygen desaturation, bleeding, perforation, and pancreatitis.

RESULTS

Covered SEMS were successfully deployed in all patients in both groups. Stent migration occurred in 6 patients (16%) in group 1 and 1 patient (3%) in group 2, P=0.075. Overall, complications occurred in 18 patients in group 1 and 4 patients in group 2, P=0.006. There was no pancreatitis in either group.

CONCLUSIONS

Deployment of covered SEMS without prior ES in patients with distal common bile duct obstruction owing to pancreatic cancer is feasible and prevents the development of complications such as stent migration, bleeding, and perforation.

Temporary placement of covered self-expandable metal stents in benign biliary strictures: a new paradigm? (with video)

BACKGROUND

Benign biliary strictures (BBS) are usually managed with plastic stents, whereas placement of uncovered metallic stents has been associated with failure related to mucosal hyperplasia.

OBJECTIVE

We analyzed the efficacy and safety of temporary placement of a covered self-expanding metal stent (CSEMS) in BBS.

DESIGN

Patients with BBS received temporary placement of CSEMSs until adequate drainage was achieved; confirmed by resolution of symptoms, normalization of liver function tests, and imaging.

SETTING

Tertiary-care center with long-standing experience with CSEMSs.

PATIENTS

Seventy-nine patients with BBS secondary to chronic pancreatitis (32), calculi (24), liver transplant (16), postoperative biliary repair (3), autoimmune pancreatitis (3), and primary sclerosing cholangitis (1).

INTERVENTION

ERCP with temporary CSEMS placement. Removal of CSEMSs was performed with a snare or a rat-tooth forceps.

MAIN OUTCOME MEASUREMENTS

End points were efficacy, morbidity, and clinical response.

RESULTS

CSEMSs were removed from 65 patients. Resolution of the BBS was confirmed in 59 of 65 patients (90%) after a median follow-up of 12 months after removal (range 3-26 months). If patients who were lost to follow-up, developed cancer, or expired were considered failures, then an intent-to-treat global success rate of 59 of 79 (75%) was obtained. Complications associated with placement included 3 post-ERCP pancreatitis (4%), 1 postsphincterotomy bleed (1%), and 2 pain that required CSEMS removal (2%). In 11 patients (14%), the CSEMS migrated. In 1 patient, CSEMS removal was complicated by a bile leak that was successfully managed with plastic stents.

LIMITATION

Pilot study from a single center.

CONCLUSIONS

Temporary CSEMS placement in patients with BBS offers a potential alternative to surgery.

Treatment of malignant biliary obstruction with a PTFE-covered self-expandable nitinol stent

Objective

We wanted to determine the technical and clinical efficacy of using a PTFE-covered self-expandable nitinol stent for the palliative treatment of malignant biliary obstruction.

Materials and Methods

Thirty-seven patients with common bile duct strictures caused by malignant disease were treated by placing a total of 37 nitinol PTFE stents. These stents were covered with PTFE with the exception of the last 5 mm at each end; the stent had an unconstrained diameter of 10 mm and a total length of 50-80 mm. The patient survival rate and stent patency rate were calculated by performing Kaplan-Meier survival analysis. The bilirubin, serum amylase and lipase levels before and after stent placement were measured and then compared using a Wilcoxon signed-rank test. The average follow-up duration was 27.9 weeks (range: 2-81 weeks).

Results

Placement was successful in all cases. Seventy-six percent of the patients (28/37) experienced adequate palliative drainage for the remainder of their lives. There were no immediate complications. Three patients demonstrated stent sludge occlusion that required PTBD (percutaneous transhepatic biliary drainage) irrigation. Two patients experienced delayed stent migration with stone formation at 7 and 27 weeks of follow-up, respectively. Stent insertion resulted in acute elevations of the amylase and lipase levels one day after stent insertion in 11 patients in spite of performing endoscopic sphincterotomy (4/6). The bilirubin levels were significantly reduced one week after stent insertion (p < 0.01). The 30-day mortality rate was 8% (3/37), and the survival rates were 49% and 27% at 20 and 50 weeks, respectively. The primary stent patency rates were 85%, and 78% at 20 and 50 weeks, respectively.

Conclusion

The PTFE-covered self-expandable nitinol stent is safe to use with acceptable complication rates. This study is similar to the previous studies with regard to comparing the patency rates and survival rates.

ePTFE/FEP-covered metallic stents for palliation of malignant biliary disease: can tumor ingrowth be prevented?

PURPOSE

To determine the application and clinical effectiveness of ePTFE/FEP-covered metallic stents for palliation of malignant biliary disease, and to evaluate the efficiency of stent coverage in preventing tumor ingrowth.

METHODS

During a 3-year period, 36 patients with malignant obstructive jaundice were treated with ePTFE/FEP-covered stents, with or without proximal side holes. The stricture was located in the lower common bile duct (CBD) in 18 cases, the upper CBD in 9, the lower common hepatic duct (CHD) in 6, and the upper CHD in 3 patients.

RESULTS

Thirty-seven covered stents were percutaneously implanted. The technical success rate was 97%. Reintervention was required in 6 cases. The 30-day mortality rate was 40%, not procedure-related. Mean survival was 128 days. Primary patency rates were 100%, 55.5%, and 25% at 3, 6, and 12 months, respectively, while the assisted patency rate was 100% at 12 months. Stents without side holes had higher primary patency rates compared with those with side holes, where occlusion was always due to tumor ingrowth. Tumor ingrowth did not occur in the completely covered stents. No stent dysfunction due to sludge incrustation was found. Complications were 1 case of arterial laceration that occurred during percutaneous transhepatic cholangiography, and a subcapsular hematoma and 1 case of bile peritonitis, that both occurred during primary stenting. No complications followed the secondary stenting technique.

CONCLUSION

ePTFE/FEP-covered metallic stents are safe and effective for palliation of malignant biliary disease. The presence of the ePTFE/FEP coating is likely to prevent from tumor ingrowth.

A comparison of covered and uncovered Wallstents for the management of distal malignant biliary obstruction

BACKGROUND

The efficacy and complications of covered self-expandable metal stents (SEMS) remain controversial.

OBJECTIVE

We conducted this study to compare the efficacies and complication rates of covered and uncovered SEMS in malignant biliary obstruction.

DESIGN

Data on patients who underwent endoscopic retrograde biliary drainage with covered or uncovered Wallstents for the palliation of unresectable distal malignant biliary obstruction were collected. Stent patency, complications, and causes of stent occlusion were analyzed.

SETTING

We collected the data retrospectively.

PATIENTS

A total of 77 patients received Wallstents for unresectable distal malignant biliary obstruction.

INTERVENTIONS

Endoscopic sphincterotomy was performed, and a Wallstent was deployed after guidewire passage. Polyurethane-covered Wallstents were used in 36 patients and uncovered Wallstents in 41 patients.

RESULTS

Stent migration occurred in 3 of the covered Wallstent group and in 1 of the uncovered Wallstent group. Cholecystitis occurred in 1 of the covered Wallstent group but in none of the uncovered Wallstent group. Stent occlusion occurred after a mean of 398 days in the covered group and after 319 days in the uncovered Wallstent group (P > .05). Stent patency rates were 83%, 78%, 67%, and 54% at 100, 200, 300, and 400 days, respectively, in covered group and 83%, 66%, 54%, and 36% in the uncovered group, which was not significantly different.

LIMITATIONS

This study is not a prospective randomized study and sample size is not large.

CONCLUSIONS

Covered Wallstents are safe with acceptable complication rates. However, we found no significant difference between the stent patencies of covered and uncovered Wallstents.

Covered versus uncovered wallstent for malignant extrahepatic biliary obstruction: a cohort comparative analysis

BACKGROUND & AIMS

We examined the use of both covered and uncovered Wallstents in patients with malignant extrahepatic biliary obstruction to determine whether use of covered Wallstents prolonged stent patency without increasing procedure-related complications.

METHODS

Commercially available silicone-covered Wallstents were prospectively evaluated in 98 patients who underwent insertion from December 2002-December 2004. Those data were compared with data obtained by retrospectively studying 108 consecutive patients who underwent endoscopic insertion of uncovered Wallstents between January 2000-November 2002, and for whom accurate and complete follow-up details were available.

RESULTS

The mean stent patency was similar for both groups, 148.9 days (range, 3-667 days) for covered Wallstents and 143.5 days (3-910 days) for uncovered Wallstents (P = .531). The 2 groups also did not significantly differ in terms of cumulative stent patency according to the Kaplan-Meier lifetime table. The incidence of mild pancreatitis was similar in both groups, occurring in 6 patients with covered stents (6/98, 6.1%) and 2 patients with uncovered stents (2/108, 1.9%) (P = .154). Excluding those patients who had previously undergone cholecystectomy, acute cholecystitis occurred in 5 of 88 patients with covered Wallstents (6.1%) and 1 of 100 patients with uncovered stents (1%) (P = .104). Stent migration occurred in 6 patients with covered stents (6.1%) and 0 patients with uncovered stents (P = .011).

CONCLUSION

Covered Wallstents might not prolong stent patency compared with uncovered Wallstents when used in the management of malignant extrahepatic biliary obstruction.

Self-expandable metallic stents for malignant biliary obstruction: Efficacy on proximal and distal tumors

AIM: To compare the efficacy of self-expandable metallic stents (EMS) in the treatment of distal and proximal stricture of malignant biliary tumors.

METHODS: From March 1995 to June 2004, 61 patients (40 males, 21 females) with malignant biliary obstruction who received self-expandable metallic stent implantation were reviewed retrospectively. The stents were inserted by an endoscopic or percutaneous transhepatic method. We tried to place two stents in the biliary system in T or Y configuration in cases of hilar tumors with bilateral hepatic duct obstruction. The end points of the study were stent occlusion or patient death.

RESULTS: The mean time of stent patency was 421 ± 67 d in the group of proximal stricture( group I) and 168 ±18 d in the group of distal stricture (group II). The difference was significant in borderline between the two groups (P   = 0.0567). The mean survival time was 574 ± 76 d in group I and 182 ± 25 d in group II. There was a significant difference between the two groups (P  = 0.0005).

CONCLUSION: EMS implantation is a feasible, palliative method for unresectable malignant biliary obstruction. The clinical efficacy of EMS in patients with proximal hilar tumors is better than that in patients with distal tumors.

Efficacy and safety of the covered Wallstent in patients with distal malignant biliary obstruction

BACKGROUND

The aim of this study was to evaluate the efficacy and the safety of the covered Wallstent, a commercially available silicone-covered, self-expandable metallic stent (covered Wallstent), for the treatment of distal malignant biliary obstruction.

METHODS

Sixty-nine consecutive patients with unresectable distal malignant biliary obstruction who underwent covered Wallstent placement between October 2001 and October 2003 were studied at 4 affiliated hospitals.

RESULTS

Mean stent patency and mean survival were 139.1 days and 200.9 days, respectively. Stent occlusion occurred in 7 cases (10.1%), but tumor ingrowth was not observed. Seventeen complications, including 5 cholangitis (7.2%), 4 stent migration (5.8%), 4 cholecystitis (5.8%), and 4 pancreatitis (5.8%) were observed in 16 patients (23.2%). Stent misplacement was observed in 7 patients (10.1%).

CONCLUSIONS

Covered Wallstent is effective in preventing tumor ingrowth for the treatment of distal malignant biliary obstruction. However, the overall complication rate may be higher than uncovered self-expanding metal stents and covered self-expanding metal stents of different design.

Metallic Stents for Treatment of Benign Biliary Obstruction: A Long-term Study Comparing Different Stents

PURPOSE

To investigate the role of metallic stents in the treatment of benign biliary strictures and analyze the differences in primary patency associated with the various types of stents deployed.

MATERIALS AND METHODS

Between 1990 and 1997, 21 patients with benign obstructive jaundice were treated with transhepatic placement of metallic stents (11 Wallstents in 10 patients, nine Palmaz stents in seven patients, and four tantalum Strecker stents in four patients). Nineteen patients presented with strictures not responding to balloon angioplasty (postsurgical, n = 13; cholangitis, n = 5; unknown, n = 1). Estimates for cumulative patency, patency rate in the different stent groups, and survival were calculated with use of life-table analysis; the log-rank test was used to compare the different stent groups. The prognostic relevance of the selected variables-stent type, stent length, etiology, and location-were modeled with respect to patency according to Weibull distribution.

RESULTS

The median follow-up time was 80.5 months (range, 2-116 months). The median survival time was 91 months. One patient was lost to follow-up after 3 months. Repeat intervention for recurrent obstructive jaundice was necessary in 11 patients (55%), and the median patency rate was 26 months (range, 2-96 months). The Palmaz stent was the most effective in achieving long-term patency, with a median patency duration of 36 months (range, 22-96 months), versus 9 months (range, 3-67 months) for the Wallstent and 6 months (range, 2-15 months) for the tantalum Strecker stent. The cumulative patency rate with the Palmaz stent was significantly higher than for the tantalum Strecker stent (log-rank test, P = .017) and nonsignificantly higher compared with the Wallstent (log-rank test, P = .07). Multivariate analysis showed that the type of stent (Wald test, P = .003) and stent length (Wald test, P < .0001) influenced the patency rate.

CONCLUSIONS

These results suggest that the type of stent and the stent length have a significant influence on the patency rate. In this series, the Palmaz stent was most effective in achieving long-term patency in benign biliary strictures.

Efficacy and complications of covered Wallstents in malignant distal biliary obstruction

BACKGROUND

This study evaluated the efficacy and the complications associated with the use of the covered Wallstent in the setting of unresectable malignant biliary obstruction.

METHODS

Between March 2001 and January 2003, all patients with distal malignant biliary obstruction that required drainage were treated with a covered Wallstent. Every 2 months, the patients were evaluated clinically and biochemical tests of liver function were obtained. Data were recorded for the following variables: early complications (within 30 days of stent placement), early and late stent occlusion, duration of stent patency, need for subsequent biliary intervention, and patient survival.

RESULTS

A total of 88 covered Wallstents were inserted in 80 patients. Stent patency rates at 3, 6, and 12 months were 90%, 82%, and 78%, respectively. Complications included stent migration (5), stent occlusion (12), episodes of cholecystitis (3), and episodes of post-ERCP pancreatitis (5). Biliary intervention was required in 9 patients subsequent to placement of the initial covered Wallstent.

CONCLUSIONS

Deployment of a covered Wallstent is safe and relatively easy. It achieves biliary drainage with an acceptable risk to benefit ratio in the majority of patients with distal malignant biliary obstruction.

Flared Polyurethane-covered Self-expandable Nitinol Stent for Malignant Biliary Obstruction

PURPOSE

To determine the technical efficacy and safety of a flared polyurethane-covered self-expandable nitinol stent in the management of malignant biliary obstruction and to evaluate its clinical efficacy by estimating stent patency and patient survival rates.

MATERIALS AND METHODS

Thirteen patients with common bile duct strictures (nonhilar) caused by malignant disease were treated by placement of 13 nitinol stents. The stents used include a flared section in the proximal portion (12 mm in diameter and 10 mm in length) and a section in the remnant portion that is fully covered with high-elasticity polyurethane, with an unconstrained diameter of 10 mm and a total length of 50-80 mm. Patient survival and stent patency rates were calculated with use of Kaplan-Meier survival analysis. The follow-up bilirubin and serum amylase and lipase levels were calculated, and the differences in means were evaluated with use of a Wilcoxon signed-rank test. The average follow-up duration was 22.9 weeks (range, 8-56 weeks).

RESULTS

Placement was successful in all cases. The 30-day mortality rate was 0%. The survival rates were 38% and 24% at 20 and 50 weeks, respectively. Seventy-seven percent of study patients had adequate palliative drainage during their the remainder of their lives. The stent patency rates were 71% and 48% at 20 and 50 weeks, respectively. Three patients (23%) presented with stent occlusion requiring repeat intervention. There were no procedure-related complications such as proximal or distal migration. No complications occurred other than stent occlusion. One patient's stent was removed under endoscopic guidance 15 weeks after its insertion. Bilirubin levels had significantly decreased 1 week after stent insertion (P <.001).

CONCLUSION

Preliminary results suggest that placement of a flared polyurethane-covered self-expandable nitinol stent is feasible and effective in achieving biliary drainage. The stents do not migrate, but there is tumor ingrowth into the flared portion of the stent. Treatment of a larger group of patients will be mandatory to validate these long-term results.

New ePTFE/FEP-covered stent in the palliative treatment of malignant biliary obstruction

PURPOSE

To determine the technical efficacy and safety of an expanded polytetrafluoroethylene and fluorinated ethylene propylene (ePTFE/FEP)-covered metallic stent in the management of malignant biliary obstruction and to evaluate its clinical efficacy by estimating stent patency and patient survival rates.

MATERIALS AND METHODS

Twenty-six patients with common bile duct stricture caused by malignant disease were treated by placement of 29 stents. The stent consists of an inner ePTFE/FEP lining and an outer supporting structure of nitinol wire. Multiple wire sections elevated from the external surface provide anchoring. Stents are available in two versions, with or without holes in the proximal stent lining. Holes should provide drainage of the cystic duct or biliary side branches when covered by the proximal stent end. Clinical evaluation and assessment of serum bilirubin and liver enzyme levels were done before stent placement and at 1, 3, 6, and 9 months. Average follow-up duration was 5.4 months (range, 5 d to 12.5 mo).

RESULTS

Placement was successful in all cases. The 30-day mortality rate was 11.5%. The survival rates were 40% and 15% at 6 and 12 months, respectively. Eighty-four percent of patients had adequate palliative drainage during their lifetime. The stent patency rates were 91%, 77%, and 77% at 3, 6, and 12 months, respectively. Four patients (16%) presented with stent occlusion and needed repeat intervention. No migration occurred. Complications other than stent occlusion occurred in five patients (19%); among these, acute cholecystitis was observed in three patients (12%).

CONCLUSION

Preliminary results suggest that placement of this ePTFE/FEP-covered stent is feasible and effective in achieving biliary drainage. The percentage of patients undergoing lifetime palliation and the midterm patency are promising. However, the incidence of acute cholecystitis is high. Treatment of a larger group of patients is mandatory to validate these long-term results.

Polyurethane-covered metal stent for management of distal malignant biliary obstruction

BACKGROUND

The efficacy of polyurethane-covered metal expandable stents for treatment of neoplastic distal biliary obstruction was analyzed.

METHODS

Twenty-one patients with unresectable malignant tumors involving the mid to distal bile duct who were seen with obstructive jaundice were consecutively enrolled. Eighteen patients underwent endoscopic implantation of a polyurethane-covered metal stent and 3 patients underwent transhepatic insertion because of duodenal obstruction. The stent patency, complications, and patient survival were analyzed.

RESULTS

Effective biliary decompression was achieved in all patients. Adverse events were minor: mild pancreatitis (1) and cholecystitis (2) occurred within 7 days of stent insertion. Mean survival and stent patency were 233 days and 206 days, respectively. Stent occlusion occurred in 3 patients (14%) after a mean of 188 days. Tumor ingrowth through the stent mesh was not observed. However, 2 stents were occluded by tumor overgrowth and 1 by compacted alimentary debris.

CONCLUSIONS

A polyurethane membrane may prevent tumor ingrowth and reduce the occlusion rate for expandable metal stents implanted in patients with malignant obstruction of the distal bile duct.

Polyurethane-covered Nitinol Strecker stents as primary palliative treatment of malignant biliary obstruction

PURPOSE

To evaluate the clinical efficacy of the polyurethane-covered Nitinol Strecker stent in the treatment of patients with malignant biliary obstruction.

METHODS

Twenty-three covered stents produced by us were placed in 18 patients with malignant biliary obstruction. Jaundice was caused by cholangiocarcinoma (n = 5), pancreatic cancer (n = 6), gallbladder cancer (n = 4), metastatic lymph nodes (n = 2), and tumor of the papilla (n = 1).

RESULTS

The mean patency period of the stents was 37.5 weeks (5-106 weeks). Recurrent obstructive jaundice occurred in two patients (11%). Adequate biliary drainage over 50 weeks or until death was achieved in 17 of 18 patients (94.4%). Late cholangitis was observed in two patients whose stents bridged the ampulla of Vater. Other late severe complications were not encountered.

CONCLUSION

Although more study is necessary, our results suggest the clinical efficacy of our covered Nitinol Strecker stent in the management of obstructive jaundice caused by malignant diseases.

In vivo study of polyurethane-coated Gianturco-Rosch biliary Z-stents

PURPOSE

Prototypes of Gianturco-Rosch Z-stents coated with polycarbonate urethane (PCU) were placed in the biliary tree of pigs, in order to test their biomechanical behavior, stability, and biocompatibility.

METHODS

The stents were surgically implanted in the common bile duct of three pairs of pigs, which were killed after 1, 3, and 6 months respectively. Explanted livers from pigs of the same race, age, and size were used to provide comparative data. The bile ducts were radiologically and histopathologically examined; the stents were processed and examined by scanning electron microscopy.

RESULTS

No complications occurred and the animals showed a normal weight gain. The main bile duct appeared radiologically and macroscopically dilated, but the stents proved to be in place. Histologically, the bile duct epithelium was destroyed, but neither hyperplastic nor inflammatory fibrotic reactions of the wall were evident. Both the metallic structure and the polymeric coating of the stents were intact. A layer of organic material with a maximum thickness of approximately 3 micron was evident on the inner surface of the stents.

CONCLUSION

The present in vivo study demonstrates the biocompatibility, efficacy, and stability of PCU-coated Gianturco-Rosch stents in the biliary environment.

Interventional radiology and the use of metal stents in nonvascular clinical practice: a systematic overview

PURPOSE

The intent of this systematic overview was to describe the clinical role of metal stents in nonvascular health care interventions and the level of evidence supporting their use.

MATERIALS AND METHODS

Structured searches of Medline were conducted and limited to original peer-reviewed articles published in English.

RESULTS

Clinical practice involving metal stents was reported in more than 109 clinical series involving 4,753 patients. Stents were placed mainly for palliation of malignant biliary, esophageal, and airway obstruction in patients who were untreatable or had surgically unresectable lesions. Assessment of these interventions has so far centered on safety and technical success. Efficacy, quality of life, and costing factors were not routinely reported. Randomized trial evidence was available but limited; six randomized trials involving metal stents have been reported. Three trials involved biliary malignant obstruction, and all three reported metal stent (132 patients) palliation to be superior to plastic stent palliation (136 patients) based on longer patency and lower reintervention costs. Safety and complication differences between stents, however, were inconsistent across trials. In three trials involving esophageal malignant obstruction, metal stent (82 patients) palliation was reported to be superior to plastic stent (41 patients), based on lower complication and reintervention rates, and superior to laser therapy (18 patients), based on better dysphagia relief.

CONCLUSION

Use of metal stents has been reported for obstructed ducts and passageways of most body systems. There is, however, limited controlled trial evidence confirming the advantages of their use over plastic stents or other forms of treatment.

Materials and biomaterials for interventional radiology

Devices used in interventional radiology have significantly developed in the past few years. In order to understand the trends of this development, we analyzed how new interventional devices are progressively incorporating materials having original physical properties, and how developers are today progressively turning towards biomaterials, with respect to the new regulatory environment, and the requirements of biocompatibility.

Therapy for biliary stenoses and occlusions with use of three different metallic stents: single-center experience

PURPOSE

The authors report their experience with three different metallic stents for the treatment of biliary obstructions during a 6.5-year period (between February 1989 and June 1995).

MATERIALS AND METHODS

In an uncontrolled, nonrandomized, and prospective study, 168 patients with obstructive jaundice underwent transhepatic placement of metallic stents. Patients were excluded if they were deemed too ill for intervention or had incorrectable coagulopathy. Those patients undergoing external and/or intraluminal radiation therapy, and patients in whom an internal-external catheter was kept in place after insertion of a stent were not included. Inoperable malignant disease was diagnosed in 157 patients (93.5%). Eleven patients presented with a benign biliary stricture that could not be managed by means of angioplasty. One hundred fifty-five Wallstents were placed in 122 patients, 65 tantalum Strecker stents were placed in 30 patients, and 18 Memotherm stents were placed in 16 patients. The patients were followed until September 1996 or until death.

RESULTS

Regarding malignant obstruction, the 30-day mortality rate was 10.7% without any procedure-related death, and overall survival rates after 100 and 200 days were 63% and 22%, respectively. Regarding benign stricture, eight of 11 patients were alive after a median follow-up of 50.6 months without any 30-day mortality. Major complications occurred in 16 patients (10.2%) who had malignancy, and in two patients (18.2%) with benign biliary disease. The cumulative patency rate in malignant obstructions was significantly higher for the Wallstent than for the Memotherm stent (P < .05) and nonsignificantly higher for the Wallstent than for the tantalum Strecker stent (P > .05). Reintervention due to recurrent obstructive jaundice was necessary in 28 patients (17.8%) with malignancy, and in six patients (54.5%) with benign stricture.

CONCLUSIONS

The Wallstent is the most effective in achieving long-term palliation in patients with malignant obstructive jaundice. The treatment of benign biliary strictures with metallic stents is associated with a low long-term patency rate.