ORIGINAL ARTICLE   Free access

Minerva Urology and Nephrology 2023 April;75(2):194-202

DOI: 10.23736/S2724-6051.23.05152-2

Copyright © 2023 EDIZIONI MINERVA MEDICA

language: English

Animal model assessment of a new design for a coated mitomycin-eluting biodegradable ureteral stent for intracavitary instillation as an adjuvant therapy in upper urothelial carcinoma

Federico SORIA ^{1, 2} ✉, Julia E. DELACRUZ ¹, Salvador D. AZNAR-CERVANTES ³, Javier ARANDA ¹, Luna MARTÍNEZ-PLA ¹, Marcos CEPEDA ⁴, Alberto PÉREZ-LANZAC ⁵, Gonzalo BUENO ⁶, Francisco M. SÁNCHEZ-MARGALLO ¹

¹ Department of Endoscopy-Endourology, Jesús Usón Minimally Invasive Surgery Center Foundation, Cáceres, Spain; ² Department of Experimental Surgery, Hospital Universitario Ramón y Cajal, IRYCIS, Madrid, Spain; ³ Department of Biotechnology, Instituto Murciano de Investigación (IMIDA), Murcia, Spain; ⁴ Department of Urology, Rio Hortega University Hospital, Valladolid, Spain, 5 Department of Urology, Ruber International Hospital, Madrid, Spain, 6 Department of Urology, Jiménez Díaz Foundation Hospital, Madrid, Spain

BACKGROUND: A major limitation in the treatment of upper urinary tract urothelial carcinoma is the limited use of adjuvant therapy due to the drawbacks of current techniques for intracavitary instillation. The aim was to assess, in a large animal model, a biodegradable ureteral stent coated with silk fibroin for mitomycin release, i.e. BraidStent-SF-MMC.
METHODS: A total of 14 female pigs with a solitary kidney underwent initial urinalysis, blood chemistry, nephrosonographic, and contrast fluoroscopy assessment of the urinary tract. Later, the BraidStent-SF-MMC was placed retrogradely to assess the mitomycin urine concentration from 0-48 hours. Follow-up was performed weekly until complete stent degradation to assess the macroscopic and microscopic changes in the urinary tract, stent complications.
RESULTS: The drug eluting stent released mitomycin for the first 12 h. The main complication was the release of obstructive ureteral coating fragments during the first to third week in 28.5 and 7.1% of animals, respectively, related to urinary pH<7.0, which destabilized the stent coating. Another complication was ureteral strictures between the fourth and sixth week in 21%. The stents were completely degraded by 6-7 weeks. There were no stent-related systemic toxic effects. The success rate was 67.5% and the complication rate was 25.7%.
CONCLUSIONS: For the first time, we have shown that a biodegradable anti-cancer drug eluting stent, BraidStent-SF-MMC, provides controlled and well-tolerated release of mitomycin into the upper urinary tract in an animal model. Mitomycin release from a silk fibroin coating could be a compelling approach for adjuvant chemotherapy instillation in upper tract urothelial carcinoma management.

KEY WORDS: Drug-eluting stents; Urinary tract; Urologic neoplasms; Fibroins