Ureteral metal stents: a tale or a tool?

Area of Science:

• Urology
• Biomaterials Science
• Medical Device Engineering

Background:

• Ureteral metal stents are available in four types: self-expandable, balloon-expandable, covered, and thermoexpandable shape-memory.
• Their use in benign ureteral strictures is still being defined, with initial applications in end-stage malignant disease.

Purpose of the Study:

• To review the current types, insertion techniques, and clinical outcomes of ureteral metal stents.
• To identify challenges and areas for future development in ureteral metal stent technology.

Main Methods:

• Review of existing literature on ureteral metal stent insertion and management.
• Discussion of common complications such as pain, hematuria, hyperplasia, encrustation, and migration.
• Mention of emerging follow-up tools like virtual endoscopy and novel stent designs.

Main Results:

• Stent insertion requires specialized techniques, and common side effects include temporary pain and hematuria.
• Urothelial hyperplasia is frequent but often regresses; encrustation and migration (81% in one study) are significant issues.
• Paclitaxel-eluting metal stents demonstrated reduced inflammation and hyperplasia in a preclinical study.

Conclusions:

• Ureteral metal stents present challenges including encrustation, migration, and impact on ureteral peristalsis.
• Further design improvements are essential for developing an ideal ureteral metal stent.
• Emerging technologies like drug-eluting stents show potential for improving outcomes.