Metal Mesh Stents for Ureteral Obstruction Caused by Hormone-Resistant Carcinoma of Prostate

Abstract

Metal mesh ureteral stents give poor palliation in distal strictures caused by hormone-refractory carcinoma of the prostate. Permanent nephrostomy may be a more acceptable alternative in these patients with short life expectancies.

Advances in ureteral stent technology

“…In vitro studies with poly(ethylene oxide)/polyurethane composite hydrogel (Aquavene) showed promising results, with superior resistance to encrustation and intraluminal blockage over 24 weeks [18]. Other materials used recently as permanently implanted stents for relieving malignant obstructions and ureteral strictures are metallic, super-alloy, titanium or nickel/titanium stents designed to be covered by normal urothelium [1,29,40,42]. However, the extent to which epithelialization takes place remains to be seen.…”

“…In the last few years, several clinical studies have focused on assessment of new implantable stents, which are expandable and permanent [1,29,30,40,42]. Time will tell if these can remain in the host without becoming a nidus for infections, encrustation, toxicity, and other adverse eects.…”

Resistance to Extrinsic Compression and Maintenance of Intraluminal Flow in Coil-Reinforced Stents (Silhouette® Scaffold Device): An In Vitro Study

“…4 The maintenance of its patency is crucial for success, but high early failure rates have been reported and reach up to 58%. 1,8,13 Factors related to stent failure have been described and include stent encrustation and luminal obstruction caused by debris and mucus. 8 Also, since open flow dynamics predominates in this setting, failure to maintain cross-sectional stability leads to a decrease in urine flow.…”

“…1 Urinary drainage in this setting was first described by Gibbons et al 2 in 1976. Whether or not to perform urinary drainage should be an individualized decision 1 and can be executed percutaneously with the use of a nephrostomy tube or through endoscopic transurethral retrograde placement of a ureteral stent.…”

Initial experience of a novel ureteral silicone-covered metallic mesh stent in malignant ureteric obstruction

“…Many metallic ureteric stents have been developed to overcome the limitations of conventional PCN or double-J stents. Previously developed ureteric uncovered metallic mesh stents tend to be easily obstructed by urothelial hyperplasia or tumor ingrowth [4,5]. Available metallic ureteric stents include Allium® URS, Memokath™-051, Resonance®, and Uventa™.…”