[Metallic ureteral stents. Present and future.]

Area of Science:

• Urology
• Biomedical Engineering
• Materials Science

Background:

• Ureteral obstruction, particularly of malignant or complicated benign origin, presents significant management challenges.
• Conventional drainage techniques often involve external diversions with associated adverse effects and frequent replacements.
• Metallic stents have evolved as a potential alternative, aiming for single-procedure resolution without external diversions.

Purpose of the Study:

• To review the evolution and current status of metallic ureteral stents.
• To identify the advantages and limitations of metallic ureteral stents in managing ureteral obstruction.
• To explore future directions for improving metallic stent design and efficacy.

Main Methods:

• Literature review of metallic stent development for ureteral applications.
• Analysis of design evolution in response to the urinary tract environment and ureteral dynamics.
• Examination of current challenges and potential solutions, including bioengineering approaches.

Main Results:

• Early metallic stents faced high failure rates due to unsuitable designs for the urinary tract.
• Modern metallic stents (e.g., Memokath, Uventa, Allium Medical URS-stent, Resonance) show improved success rates.
• Current limitations include obstructive urothelial hyperplasia, encrustation, and migration, restricting widespread use.

Conclusions:

• Metallic ureteral stents offer advantages over conventional methods but are limited by adverse effects.
• Understanding physiopathological mechanisms is crucial for mitigating these side effects.
• Future developments in drug-eluting, biocoated, or biodegradable metallic stents hold promise for the ideal solution.