Clinical outcomes of nitinol and stainless steel uncovered metal stents for malignant biliary strictures: is there a difference?
BACKGROUND
Self-expandable metal stents (SEMSs) made from nitinol (N) were developed as a potentially more effective alternative to conventional stainless steel (SS) stents.


OBJECTIVE
To compare clinical outcomes of N versus SS stents in the management of malignant biliary strictures.


METHODS
Retrospective study.


METHODS
Tertiary-care cancer center.


METHODS
All patients with first-time N (Flexxus) and SS (Wallstent) uncovered biliary SEMSs placed between January 2006 and October 2007.


METHODS
SEMS placement.


RESULTS
A total of 81 N and 96 SS stents were placed. The most common cancer diagnosis was pancreatic (80.2% N; 62.5% SS; P = .06). The most frequent site of stricture was the common bile duct (85.2% N; 86.5% SS; P = .31). Biliary decompression was achieved in 93.8% of the N group and 86.4% of the SS group (P = .22). Immediate stent manipulation was required in 4 patients in each group. Subsequent intervention for poor drainage was performed in 17 N (21%) and 26 SS (27%) stents at mean times of 142.1 days (range, 5-541 days; median, 77 days) and 148.1 days (range, 14-375; median, 158.5), respectively (P = .17). The occlusion rate between N and SS stents was not significant (P = .42). The overall durations of stent patency in the N and SS group were similar (median 129 and 137 days, respectively; P = .61), including the subgroup analysis performed on patients with pancreatic cancer (P = .60) and common duct strictures (P = .77). Complication rates were low in both groups (early: 3.7% N, 6.3% SS; late: 2.5% N, 3.1% SS). Ninety percent underwent chemotherapy and 38% radiation therapy in each group.


CONCLUSIONS
Retrospective design.


CONCLUSIONS
Similar outcomes were achieved with N and SS stents regarding efficacy, duration of stent patency, occlusion rates, and complications. Our results are most applicable to patients with common duct strictures and pancreatic cancer.
Department of Gastroenterology, Hepatology, and Nutrition, University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030-4009, USA.
Brian R
BR
Weston
William A
WA
Ross
Jun
J
Liu
Jeffrey H
JH
Lee
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000497:Alloys; D014670:Ampulla of Vater; D018281:Cholangiocarcinoma / Q000628:therapy*; D001651:Cholestasis, Extrahepatic / Q000628:therapy*; D003138:Common Bile Duct Neoplasms / Q000556:secondary / Q000628:therapy*; D019544:Equipment Failure Analysis; D005260:Female; D006500:Hepatic Duct, Common; D006801:Humans; D008111:Liver Function Tests; D008113:Liver Neoplasms / Q000556:secondary* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000556:secondary / Q000628:therapy*; D011474:Prosthesis Design; D012008:Recurrence; D019233:Retreatment; D012189:Retrospective Studies; D013193:Stainless Steel; D015607:Stents
D000497:Alloys; D013193:Stainless Steel; C013616:nitinol