Treatment of Malignant Biliary Obstruction with a PTFE-Covered Self-Expandable Nitinol Stent

Abstract

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.he treatment for malignant biliary obstruction includes performing surgery and interventional procedures such as insertion of a self-expanding metal stent under fluoroscopic and/or endoscopic guidance (1 6). Self-expanding metal stents have become a well-accepted palliative procedure for relieving inoperable malignant biliary obstruction. The most common causes of occlusion of an uncovered stent are sludge formation, proximal and distal tumor overgrowth, tumor ingrowth and stone formation (1,7,8). The obstruction rates for uncovered stents in a previous study varied from 5% to 100% (mean: 22%) during a 0.7 to 19 month period following stent placement (9).To improve the patency rates of metallic stents, many studies have been performed

Malignant Hilar Biliary Obstruction: Treatment by Means of Placement of a Newly Designed Y-Shaped Branched Covered Stent

“…On the other hand, a prospective study of covered stent placement for advanced hilar malignancies obtained results comparable to ours, i.e., the median patient survival time of 218 days and the median stent patency time of 375 days [11]. Various kinds of covering materials, such as polyurethane, e-PTFE, and silicone, have been currently used to cover the biliary metallic stents [10,11,[18][19][20][21][22]. In our study, a silicone was used as the covering material because it is biodurable and provides a larger lumen for bile flow by means of alleviating biofilm and sludge formation [23,24].…”

“…Despite the advantage of preventing tumor ingrowth, use of the covered stent can be plagued by stent migration [20][21][22]25]. Various methods of preventing stent migration have been described [10,11,26].…”

Suprapapillary versus Transpapillary Stent Placement for Malignant Biliary Obstruction: Which Is Better?

“…They thought that the incidence of pancreatitis was high because the main pancreatic duct is not completely obstructed and the distal pancreas is preserved in patients with nonpancreatic cancer. Because the patients in group B in the present study had an approximately 11.4 times greater risk of pancreatitis than those in group A, the incidence of pancreatitis (14.9%) is higher in the present study, which included 68.4% nonpancreatic cancer cases, than in previous studies (9)(10)(11)(12)(13)(14)(15) that included less than 40% nonpancreatic cancer cases (incidence rate of pancreatitis o 7%) and lower than in a study by Han et al (15) that included 78.4% nonpancreatic cancer cases (29%). We considered that nonpancreatic cancer is associated with a high incidence of pancreatitis.…”

Percutaneous Placement of Self-Expandable Metallic Stents in Patients with Obstructive Jaundice Secondary to Metastatic Gastric Cancer after Gastrectomy

“…Stent occlusion was diagnosed according to clinical, laboratory, and radiologic findings. In the case of stent occlusion, we performed decompressions of the bile duct by secondary percutaneous interventional procedures depending on the condition of the patients (20). …”