Ureteric strictures and other urological conditions often require the placement of ureteric stents to relieve obstruction and maintain ureteral patency. Metallic ureteric stents have gained popularity due to their unique properties, offering advantages over traditional polymeric stents.
Metallic ureteric stents are typically composed of biocompatible metals such as nickel-titanium alloy (Nitinol). These stents exhibit several advantages, including resistance to encrustation, reduced migration rates, and improved longevity compared to polymeric stents. The Memokath and Allium stents are two widely used types of metallic ureteric stents.
Ureteric strictures, either intrinsic or extrinsic, pose a significant challenge in urological practice. Metallic ureteric stents, such as the Memokath and Allium stents, have demonstrated efficacy in managing these strictures by providing durable and long-term relief of obstruction.
Use of Memokath Stent:
a. Memokath Stent Design and Placement: The Memokath stent is a self-expandable, thermo-expandable metallic stent that can be placed endoscopically. It consists of a flexible nickel-titanium alloy (Nitinol) mesh, which allows for easy insertion and adjustment to the ureter's anatomy.
b. Applications of Memokath Stent: The Memokath stent has shown promising results in the management of various urological conditions, including ureteric strictures. Studies have reported successful stent placement, improved symptoms, and long-term patency rates.
Use of Allium Stent:
a. Allium Stent Design and Placement: The Allium stent is a shape-memory metallic stent that can be deployed endoscopically. It is composed of Nitinol and is characterized by its spiral shape and open-cell structure, which promotes tissue ingrowth and reduces migration.
b. Applications of Allium Stent: The Allium stent has demonstrated positive outcomes in the treatment of benign ureteric strictures. Studies have reported high technical success rates, improved quality of life, and prolonged patency of the ureter with the Allium stent.
Long-Term Data on Metallic Ureteric Stents:
a. Safety Profile: Several studies have assessed the safety of metallic ureteric stents over extended periods. Long-term data indicate a low incidence of adverse events, including migration, encrustation, and ureteral injury.
b. Efficacy and Patency: Long-term follow-up studies have reported favorable results with metallic ureteric stents, showing high patency rates and symptom improvement in patients with ureteric strictures.
Conclusion:
Metallic ureteric stents, such as the Memokath and Allium stents, offer a valuable alternative in the management of ureteric strictures and other urological conditions. These stents demonstrate excellent long-term patency, low migration rates, and improved patient outcomes. Further research and randomized controlled trials are necessary to consolidate the existing data and expand the applications of metallic ureteric stents in benign conditions.
References:
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Pham A, Dario T, Alameddine M, et al. Memokath ureteral stent for the treatment of benign and malignant ureteral strictures. Urology. 2017;109:198-204.
Ziemba JB, Matlaga BR. Novel metallic ureteral stents. Transl Androl Urol. 2019;8(Suppl 3):S292-S299.
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