nitinol and Common-Bile-Duct-Neoplasms

Self-expandable metal stents (SEMSs) made from nitinol (N) were developed as a potentially more effective alternative to conventional stainless steel (SS) stents.. To compare clinical outcomes of N versus SS stents in the management of malignant biliary strictures.. Retrospective study.. Tertiary-care cancer center.. All patients with first-time N (Flexxus) and SS (Wallstent) uncovered biliary SEMSs placed between January 2006 and October 2007.. SEMS placement.. 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.. Retrospective design.. 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.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Ampulla of Vater; Cholangiocarcinoma; Cholestasis, Extrahepatic; Common Bile Duct Neoplasms; Equipment Failure Analysis; Female; Hepatic Duct, Common; Humans; Liver Function Tests; Liver Neoplasms; Male; Middle Aged; Pancreatic Neoplasms; Prosthesis Design; Recurrence; Retreatment; Retrospective Studies; Stainless Steel; Stents

To evaluate the efficacy and safety of an expanded polytetrafluoroethylene-fluorinated ethylene-propylene (ePTFE/FEP)-covered metallic stent in the management of malignant biliary obstruction. Eighty consecutive patients with malignant common bile duct strictures were treated by placement of 83 covered metallic stents. The stent-graft consists of an inner ePTFE/FEP lining and an outer supporting structure of nitinol wire. Clinical evaluation, assessment of serum bilirubin and liver enzyme levels were analyzed before biliary drainage, before stent-graft placement and during the follow-up period at 1, 3, 6, 9 and 12 months. Technical success was obtained in all cases. After a mean follow-up of 6.9+/-4.63 months, the 30-day mortality rate was 14.2%. Survival rates were 40% and 20.2% at 6 and 12 months, respectively. Stent-graft patency rates were 95.5%, 92.6% and 85.7% at 3, 6 and 12 months, respectively. Complications occurred in five patients (6.4%); among these, acute cholecystitis was observed in three patients (3.8%). A stent-graft occlusion rate of 9% was observed. The percentage of patients undergoing lifetime palliation (91%) and the midterm patency rate suggest that placement of this ePTFE/FEP-covered stent-graft is safe and highly effective in achieving biliary drainage in patients with malignant strictures of the common bile duct.

Topics: Aged; Aged, 80 and over; Alloys; Antibiotic Prophylaxis; Cholangiography; Cholestasis; Coated Materials, Biocompatible; Common Bile Duct Neoplasms; Constriction, Pathologic; Female; Humans; Liver Function Tests; Male; Middle Aged; Palliative Care; Pancreatic Neoplasms; Polytetrafluoroethylene; Postoperative Complications; Prosthesis Design; Stents; Survival Rate

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

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