Stenting For Malignant Biliary Obstruction Research Articles

Histologic influence of paclitaxel-eluting covered metallic stents in a canine biliary model

Metallic stents for malignant biliary obstruction are susceptible to occlusion by tumor ingrowth or overgrowth. Paclitaxel-eluting metallic stents (PEMSs), however, may prevent occlusion from tumor ingrowth. We evaluated the safety of PEMSs in a canine biliary model by analyzing tissue reactions by histologic examination. Animal study. Six PEMSs and 5 control stents (CSs) were endoscopically placed in the bile ducts of 11 mongrel dogs and followed up for 6 weeks. The animals were euthanized at 6 weeks, and gross and microhistologic examinations were done. A comparison was made between dogs with PEMSs and dogs with CSs. All 11 stents were successfully placed in the bile ducts, although the distal ends of 2 PEMSs were partially exposed to the duodenal lumen. All 11 dogs survived until death without evidence of jaundice. Gross histologic examination showed mucosal hyperplasia in 3 of 6 dogs in the PEMS group, but there was no evidence of mucosal hyperplasia in the CS group. Microscopically, the epithelial layers at the middle and distal ends of the stented segments were significantly thicker in the PEMS dogs than in the CS group. Placement of PEMSs in normal canine bile ducts was without significant technical complications; however, local drug delivery from the PEMS resulted in significant histologic changes. Therefore, it is important to choose a drug in adequate concentrations to exert an antitumor effect without damaging the adjacent normal bilary mucosa.

Endoscopic ultrasonography guided biliary stenting for malignant biliary obstruction

Background: Endoscopic biliary drainage (EBD) is usually performed for obstructive jaundice caused by malignant lower biliary obstruction such as carcinomas in pancreas head, lower bile duct, and papilla of Vater. In cases difficult for EBD, the standard alternative method is considered to be percutaneous transhepatic biliary drainage (PTBD). However, there are many problems such as complications and the degradation of quality of daily life of the patient. Recently there have been some reports on the usefulness of endoscopic ultrasonography guided biliary stenting (EUS-BS) when EBD is difficult. In this study, we report and discuss the result and problem of EUS-BS.

Outcome of self‐expandable metallic stents in low‐grade versus advanced hilar obstruction

Self-expandable metallic stents (SEMS) are known to provide a longer patency time than plastic stents for malignant biliary obstructions including hilar obstruction. However, studies that focus on the efficacy of SEMS in low-grade and advanced hilar obstructions are still scanty. Ninety four patients with malignant hilar obstructions were enrolled (six were later excluded). Patients were divided into two groups according to their Bismuth levels. Group A were patients with Bismuth I (n = 53). Group B were patients with Bismuth II, III and IV (n = 35). Technical success, complications, jaundice resolution, stent patency time, and patients' survival were analyzed. Our intention-to-treat analysis showed that group A had a significant lower rate of post-endoscopic retrograde cholangiopancreatography (ERCP) cholangitis than group B; 16.1% versus 44.7%, (P < 0.01). Four patients from group B still had persistent jaundice. Our per protocol analysis demonstrated that median stent patency time in groups A and B were not statistically different (74 vs 60 days). Median survival time in groups A and B were also not statistically different (90 vs 75 days). In both groups, those without liver metastasis had significantly better patency and survival time than those with liver metastasis (P = 0.010 and 0.027, respectively). In patients with hilar obstruction, liver metastasis is one of the main factors that determine survival of the patient. Patency times of SEMS in both low-grade and advanced obstructions are comparable. However, in the advanced group, there is a significant risk of post-ERCP cholangitis.

WallFlex Biliary Uncovered Stent for Malignant Biliary Obstruction: Initial Experience with Feasibility, Safety, and Effectiveness

WallFlex Biliary Uncovered Stent for Malignant Biliary Obstruction: Initial Experience with Feasibility, Safety, and Effectiveness

Do the benefits of metal stents justify the costs? A systematic review and meta-analysis of trials comparing endoscopic stents for malignant biliary obstruction

A variety of stent designs has been studied for endoscopic stenting of the bile duct in patients with malignant biliary obstruction. Although metal stents are associated with longer patency, their costs are significantly higher than plastic stents. To compare clinical outcome and cost-effectiveness of endoscopic metal and plastic stents for malignant biliary obstruction by a systematic review and meta-analysis of all randomized controlled trials in this area. We conducted searches to identify all randomized controlled trials in any language from 1966 to 2006 using electronic databases and hand-searching of conference abstracts. Meta-analysis was performed with RevMan software [Review Manager (RevMan) version 4.2 for Windows. Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2003]. Seven randomized controlled trials were identified that met the inclusion criteria, and 724 participants were randomized to either metal or plastic endoscopic stents. No significant difference between the two stent types in terms of technical success, therapeutic success, 30-day mortality or complications was observed. Metal stents were associated with a significantly less relative risk (RR) of stent occlusion at 4 months than plastic stents [RR, 0.44; 95% confidence interval (CI) 0.3, 0.63; P<0.01]. The overall risk of recurrent biliary obstruction was also significantly lower in patients treated with metal stents (RR, 0.52; 95% confidence interval 0.39, 0.69; P<0.01). The median incremental cost-effectiveness ratio of metal stents was $1820 per endoscopic retrograde cholangiopancreatography prevented. Endoscopic metal stents for malignant biliary obstruction are associated with significantly higher patency rates than plastic stents as early as 4 months after insertion. Metal stents will be cost-effective if the unit cost of additional endoscopic retrograde cholangiopancreatographies per patient exceeds $1820.

Metal or plastic stent for malignant biliary obstruction: whatʼs got the most bang for your buck?

Malignant biliary obstruction is most commonly managed by the endoscopist. Various plastic and metal stents are currently available. It is important to be aware of the pros and cons of each. The identifying factors that determine the prognosis for the patient might also help determine which type of stent to place. This month's article by Moss et al., is a meta-analysis of seven randomized controlled trials analyzing the cost-effectiveness of plastic and metal stents. This meta-analysis helps guide the endoscopist in deciding what type of stent would be most beneficial and cost effective for their patients.

Self-expandable metallic stents for malignant biliary obstruction with an anomalous pancreaticobiliary junction

Anomalous pancreaticobiliary junction (APBJ) is associated with pancreaticobiliary cancer. Limited data are available on endoscopic biliary drainage for unresectable malignant biliary obstruction with APBJ. This study evaluated the efficacy and safety of self-expandable metallic stents (EMSs) for the management of malignant biliary obstruction with APBJ. Between 1993 and 2005, 324 patients with unresectable malignant biliary obstruction underwent insertion of an EMS. Six of these patients with concomitant APBJ constituted the subjects of this study. Early (</=30 days after EMS insertion) and late (>30 days after EMS insertion) stent-related complications and stent patency were evaluated in these six patients. The cause of biliary obstruction was gallbladder cancer in four patients and pancreatic cancer in two patients. Uncovered EMSs were inserted across the common channel without performance of a biliary sphincterotomy. The diameter of the uncovered EMS used was based on the diameter of the common channel. For all six patients, endoscopic biliary drainage was successful, and their jaundice subsided steadily. None of the six patients experienced early complications, including acute pancreatitis. The mean stent-related complication-free period was 163 days. Stent occlusion caused by tumor ingrowth occurred in two patients. Acute cholangitis and cholecystitis were observed in one patient each. Uncovered EMSs are effective for palliation of unresectable malignant biliary obstruction in patients who have APBJ without increasing the risk of stent-related early complications.

Self-Expandable Metallic Stents for Malignant Biliary Obstruction with Anomalous Pancreaticobiliary Junction

Background: Anomalous pancreaticobiliary junction (APBJ) is associated with pancreaticobiliary cancer. Limited data are available for biliary drainage for unresectable malignant biliary obstruction with APBJ. The aim of this study is to evaluate the efficacy and the safety of self-expandable metallic stents (EMSs) for the treatment of malignant biliary obstruction with APBJ. Methods: Between 1993 and 2005, a total of 324 patients with unresectable malignant biliary obstruction received EMS insertion. Of those, 6 patients had concomitant APBJ and were subjects to the present study. Early (≤30 days after EMS insertion) and late (>30 days after EMS insertion) stent-related complications and stent patency were evaluated in these 6 patients. Results: The cause of biliary obstruction was gallbladder cancer in 4 patients and pancreatic cancer in 2. Uncovered EMSs were inserted across the common channel without biliary sphincterotomy. The diameter of uncovered EMSs employed was chosen according to the diameter of the common channel. In all 6 patients, endoscopic biliary drainage was successful and jaundice steadily subsided. None of these 6 patients developed early complications including acute pancreatitis. Mean serum amylase level was not statistically different between before and 18-24 hrs after stent insertion (129.5 IU/l vs. 148.3 IU/l, p = 0.28). Mean stent -related complication free period was 163 days (range 83-268 days). Stent occlusion due to tumor ingrowth occurred in 2 patients (86 days and 83 days after EMS insertion, respectively). Acute cholangitis with no evidence of stent occlusion was observed in one patient 116 days after EMS placement. Acute cholecystitis occurred in one patient 106 days after stent insertion. Conclusions: Uncovered EMSs are effective for palliation of unresectable malignant biliary obstruction in patients with APBJ without increasing risk of stent-related early complication.

Covered Versus Uncovered Metallic Stents for Malignant Biliary Obstruction Induced By Unresectable Pancreatic Cancer: Comparison with Regard to the Stent Occlusions, Biliary Complications, and Re-Interventions

Background: It is reported that covered metallic stents (cMS) have a better patency rate than uncovered metallic stents (uMS) in distal malignant biliary stenosis. However, the biliary complications except for stent occlusions, for example, cholecystitis, sometimes spoil the quality of life of patients and require the re-interventions after insertion of cMS. We conducted this study to compare the biliary complications as well as the stent occlusions between cMS and uMS in patients with pancreatic cancer. Methods: Between March 2003 and August 2006, 29 patients had metallic stents inserted for distal malignant biliary stenosis induced by unresectable pancreatic cancer. They had chemotherapy with gemcitabine (GEM) and were followed-up for more than 3 months. The cMS were implanted in 13 patients (cMS group; Covered Wallstent n = 13) and the uMS in 16 patients (uMS group; JOSTENT n = 7, ZILVER STENT n = 9). Patient survival, stent patency, occlusion rate, complications, event-free survival (EFS), and re-interventions (i.e. endoscopic or percutaneous treatments) were analysed. Results: Overall mean follow up period after stent insertion was 325 days (range 95-1107). Patient characteristics were quite comparable in two groups. Median survival was 337 days in the cMS group and 277 days in the uMS group (p = 0.93). Median patency period was 413 days in the cMS group and 184 days in the uMS group, but no significance (p = 0.22). Occlusion rate was 31% (4/13; sludge n = 2, ingrowth n = 1, migration n = 1) in the cMS group and 63% (10/16; ingrowth n = 9, sludge n = 1) in the uMS group, but no significance (p = 0.18). Biliary complications with no relation to stent occlusions were seen more in the cMS group (23%; cholecystitis n = 2, cholangitis n = 1) than in the uMS group (0%) (p = 0.15). Median EFS was 222 days in the cMS group and 168 days in the uMS group (p = 0.70). The mean number of re-interventions per patient was almost equal between the two groups (cMS 0.9, uMS 1.0; p = 0.44). Conclusions: The cMS is superior to the uMS for the patency in patients with pancreatic cancer treated with GEM. However, considering the biliary complications and the number of re-interventions, there is no superiority between the both stents.

Clinical Factors Affecting the Patency of Metal Stent in Malignant Biliary Obstruction

Background and Purpose of Study: Endoscopic and percutaneous transhepatic stent placements are widely accepted as an effective treatment for palliating malignant biliary obstruction in surgically unfit or unresectable patients. However, it remains unclear which stricture- or stent-related factors influence stent patency. The goal of this study is to evaluate the metal stent patency according to various stent- and stricture-realated parameters and to identify the clinical factors influencing the stent patency before and after the procedure.

Contrast-free endoscopic stent insertion in malignant biliary obstruction

To present a case series of MRCP-guided endoscopic biliary stent placement, performed entirely without contrast injection. Contrast-free endoscopic biliary drainage was attempted in 20 patients with malignant obstruction, unsuitable for resection on the basis of tumor extent or medical illness. MRCP images were used to confirm the diagnosis of tumor, to exclude other biliary diseases and to demonstrate the stenoses as well as dilation of proximal liver segments. The procedure was carried out under conscious sedation. Patients were placed in the left lateral decubitus position. The endoscope was inserted, the papilla identified and cannulated by a papillotome. A guide wire was inserted and guided deeply into the biliary tree, above the stenosis, by fluoroscopy. A papillotomy approximately 1 cm. long was performed and the papillotome was exchanged with a guiding-catheter. A 10 Fr, Amsterdam-type plastic stent, 7 to 15 cm long, was finally inserted over the guide wire/guiding catheter by a pusher tube system. Successful stent insertion was achieved in all patients. There were no major complications. Successful drainage, with substantial reduction in bilirubin levels, was achieved in all patients. This new method of contrast-free endoscopic stenting in malignant biliary obstruction is a safe and effective method of palliation. However, a larger, randomized study comparing this new approach with the standard procedure is needed to confirm the findings of the present study.

Risk factors for cholecystitis after metal stent placement in malignant biliary obstruction

Cholecystitis related to metal stent placement is a morbid event. This study evaluated the risk factors of cholecystitis after metal stenting for malignant biliary obstruction. Between December 1997 and April 2003, 155 patients who were treated with a metal stent for malignant biliary obstruction were retrospectively enrolled. The incidence and characteristics of patients with cholecystitis were evaluated and compared with those of patients without cholecystitis. Patient characteristics and tumor or procedure-related data were recorded for the following variables: sex, age, tumor and stent length, stent type (covered vs uncovered), cholangitis before ERCP, degree of gallbladder filling with contrast medium during ERCP, primary disease type (Klatskin vs others), presence of gallbladder stones, and the relationship of the cystic duct orifice to the location of the tumor (across vs others). There were 15 (9.7%) patients diagnosed with cholecystitis after metal stent insertion. The onset of cholecystitis was on average 4.6 days (range 1 to 26) after the procedure. We found that an obstruction across the cystic duct orifice by tumor (P < .01, odds ratio 12.7) and the presence of gallbladder stone (P = .01, odds ratio 6.6) were positively related to the cholecystitis after metal stent insertion. The limitations of the study were the use of multiple types of stents and the retrospective design. This study demonstrated that an obstruction across the cystic duct by tumor and the presence of gallbladder stone were risk factors for the development of cholecystitis after metal stent placement.

Cholecystitis After Metallic Stent Placement in Patients With Malignant Distal Biliary Obstruction

Cholecystitis after metallic stent (MS) placement is an issue requiring attention. From our experience, cholecystitis seemed to occur mainly in patients with tumor involvement to the cystic duct orifice. The aim of the present study was to identify risk factors for cholecystitis in patients treated with covered or uncovered MS. We analyzed 246 patients who received MS placement (covered MS in 171 and uncovered in 75) between August 1997 and May 2005 for the treatment of unresectable distal malignant biliary obstruction. Causative diseases were as follows: pancreatic cancer in 162, papillary cancer in 10, bile duct cancer in 41, and metastatic nodes in 33 patients. Tumor involvement to orifice of the cystic duct (OCD) was diagnosed based on cholangiography and intraductal ultrasonography. Cholecystitis after MS placement was found in 13 patients (5.3%). There was no significant difference in the incidence of cholecystitis between covered (5.8%) and uncovered (4.0%) MS. By univariate analysis, tumor involvement of the OCD, MS placed above the papilla, and stricture located at midportion were associated significantly with cholecystitis. By multivariate analysis, only tumor involvement of the OCD was a risk factor, with an odds ratio of 47.206 (95% confidence interval, 5.84-381.60). Cholecystitis after MS placement is associated with tumor involvement to the orifice of the cystic duct, regardless of the type of stent.

Rate of Birubin Regression Post-Biliary Stenting in Malignant Biliary Obstruction for Initiation of Chemotherapy: How Soon Should We Repeat ERCP?

Purpose: To evaluate the rate of regression of serum bilirubin in patients with stent placement for malignant biliary obstruction. Methods: The medical records at MD Anderson Caner Center from 10/2002 to 9/2005 were reviewed for patients who underwent ERCP for malignant obstructive jaundice. The time to achieve a serum bilirubin = < 2.0 mg/dL was the primary endpoint as this is the level required by most chemotherapy protocols. Patient variables included cancer diagnosis, liver metastasis, recent chemotherapy, creatinine and INR.

Percutaneous insertion of Zilver stent in malignant biliary obstruction

We evaluated the clinical efficacy and technical feasibility of the percutaneously inserted self-expandable nitinol stent (Zilver stent) for palliation of malignant biliary obstruction. Seventeen patients with malignant tumors involving the intra- or extrahepatic bile duct who presented with obstructive jaundice underwent percutaneous insertion of a self-expandable nitinol stent. We retrospectively reviewed the hospital records of patients and evaluated the technical feasibility on stent placement, complications, patient survival, and duration of stent patency. Percutaneous biliary stenting with 27 Zilver stents was performed in 17 patients with malignant biliary obstruction. Technical success was 95%. Malposition of the stent was encountered in one patient. Minor technical problems were encountered in two patients: the introducer tip was broken during stent insertion, so endoscopic removal was done. Mean follow-up period for the 17 patients was 182 days (range 29-485 days): nine patients died of progressive disease at a mean follow-up of 151 days (range 61-371days) after stent insertion and eight patients remained alive at the final follow-up of 216 days (range 29-485 days). The median survival period for all patients was 277 days. The stent occlusion rate was 26% and the mean patency period was 280 days. In five patients, seven stents were obstructed by tumor ingrowth and overgrowth. Stent patency rates were 100%, 100%, 75%, 61%, and 41% at 1, 2, 3, 6, and 12 months, respectively. A late complication, erosive bleeding of the hepatic artery by the stent, developed in one patient. Percutaneous biliary stenting using the nitinol stent is technically feasible and safe and clinically efficacious treatment for malignant biliary obstruction, even with a minor technical problem during stent insertion.

Palliative stents for malignant biliary obstruction – a meta-analysis

Aims: To perform a systematic review, and meta-analysis, of randomised clinical trials comparing endoscopic metal and plastic biliary stents for malignant biliary obstruction.

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

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

Metal Versus Plastic Stents in Malignant Biliary Obstruction: A Meta-Analysis of the Effect on Long-Term Patency

INTRODUCTION: Placement of a biliary stent is a recognised palliative treatment for malignant biliary obstruction. Several comparative studies have been published comparing the clinical effectiveness of plastic vs metallic stents. Our aim is to perform a statistical meta-analysis of the published evidence. AIMS & METHODS: A systematic review of the published data was carried out by searching Medline, from 1991 to 2003. Non comparative data and abstracts were excluded. Occlusion rate over the follow-up or remaining survival time was the main outcome. Pooled point estimates and relative risks (RR) for occlusion were calculated. RESULTS: The review included 6 randomised controlled trials and 1 retrospective study comparing plastic versus metal stents for palliation of malignant biliary obstruction in unresectable patients. Total plastic stent population was 307 patients and total metal stent population was 331 patients (94% received an uncovered WallstentTM. Pooled results showed 19.9% of occlusions in the metal group and 41.7% in the plastic group. The risk of having an occlusion is reduced by half with a metal stent (RR=0.49). Moreover, each individual paper showed improved outcomes with metal stents. All the relative risks were inferior to 1. CONCLUSION: Clinical evidence from comparative trials show that metal stent placement (94% uncovered WallstentTM is superior to plastic stent in terms of risk of occlusion. Recent technological developments such as covered metal stents might further decrease the risk of occlusion. The more routine use of metal stents could have a positive impact on patients quality of life as retreatments should be less frequent due to a lower occlusion rate.

A Randomized Controlled Comparative Study of Covered Versus Uncovered Self-Expandable Metal Stent for Malignant Biliary Obstruction

BACKGROUND/AIM: Self-expandable metal stents (SEMS) with various designs have been developed to improve clinical efficacy for treatment of malignant biliary obstruction. However, a lot of articles previously published for SEMS study reported a variety of efficacy of covered SEMS. We performed this study to compare the safety and clinical efficacy of membrane-covered SEMS (Shim-Hanarostent, M.I.Tech, Seoul, Korea) and uncovered SEMS (Hanarostent, M.I.Tech, Seoul, Korea) in a prospective randomized controlled trial. METHODS: There were 43 consequent patients, including 26 men and 17 women, with a mean age of 70 years (range, 49-87) who were diagnosed as malignant biliary obstruction. The etiology of the strictures included pancreatic cancer (17), cholangiocarcinoma (17), ampullary cancer (4), and gall bladder cancer (5). Patients were randomly assigned to covered or uncovered stent. After insertion of the stent, we followed up symptoms, LFT and abdominal US. We performed ERCP & mother-baby scopy in occluded cases. In case of stent malfunction, we inserted plastic stent into the metal stent. The survival rates of the patient and the stent's patency rates were calculated using Kaplan-Meier survival analysis. Serum bilirubin, amylase and lipase levels were evaluated in regular interval, and the mean differences of these data before and after stenting were evaluated using a Wilcoxon signed-rank test. The average follow-up duration was median 5.3 months (range, 0.8-29 months). RESULTS: Endoscopic procedures were successful (including complete relief of jaundice) in all cases. Late complications such as tumor ingrowth etc. occurred in 11 of 21 patients with uncovered stents, as compared with 4 of 22 patients in the covered group (p < 0.05). Median stent patency of covered and uncovered stent were 216 days (range 76 to 760 days) and 127 days (range 25 to 447 days), respectively (p < 0.05). Life table analysis showed similar survival in both groups. CONCLUSION: Membrane-covered self-expandable biliary metal stents have a significantly better palliation than uncovered metal stents in the treatment of patients with malignant biliary obstruction.

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

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. 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). 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). 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.