Nickel-titanium shape memory alloy Memokath 051 ureteral stent for managing long-term ureteral obstruction: 4-year experience

Purpose: We present our 4-year experience with the thermo-expandable shape memory alloy Memokath 051 stent (Engineers and Doctors of Copenhagen, Copen hagen, Denmark) for managing long-term ureteral obstruction. Materials and Methods: We used a nickel-titanium shape memory alloy uretera l stent to treat 28 patients 29 to 86 years old (mean age 59.2). Ureteral o bstruction was caused by malignancy in 18 cases and by recurrent benign dis ease in 10. A total of 37 stents were inserted from November 1996 to Novemb er 2000 using general anesthesia. Mean followup was 19.3 months (range 3 to 35). Results: Upper tract decompression was achieved in all cases. Currently 15 stents are functional in 13 patients, while 8 patients died with a total of 13 functioning stents in place. In 7 patients 9 stents were removed for va rious reasons. There has been no radiological evidence of encrustation to d ate. No patient has been rehospitalized with stent related sepsis pain or h ematuria, resulting in improved quality of life. Conclusions: This stent seems to provide a significant benefit over convent ional Double-J (Medical Engineering Corp., New York, New York) and other me tallic stents. Its remarkable thermal memory permits removal, a feature tha t until recently was not available in any other metallic ureteral stent. Du rable and complication-free decompression of the upper tract can be achieve d with the Memokath 051.