Ureteral stents are one of the most frequently used tools in urology. These medical devices have a multitude of both prophylactic and therapeutic indications. Among the first ones, the use of stents related to the treatment of ureteral or renal stones, in renal transplant surgery and in reconstructive surgery of the upper urinary tract by endourological, laparoscopic, robotic or conventional surgical approach. Therapeutic indications are related to urinary tract decompression in obstructive uropathy and as in the conservative treatment of upper urinary tract trauma.Although it has clear benefits, unfortunately it is not free of side effects. Complications associated with ureteral stents can be classified as intraoperative, early complications if they appear between 2 and 4 weeks after stenting, and late complications, depending on the time of onset of side effects. The most common side effects are the development of vesicoureteral reflux, LUTS and stent discomfort. The complications with the highest rate of incidence are asymptomatic bacteriuria and urinary tract infection. There are also common events related to ureteral stent dislodgement and crystallization of the stent surface resulting in encrustation.

A major limitation of the treatment of low-grade upper tract urothelial carcinoma is the difficulty of intracavitary instillation of adjuvant therapy. Therefore, the aim of this in vitro study was to develop and to assess a new design of biodegradable ureteral stent coated with a silk fibroin matrix for the controlled release of mitomycin C as a chemotherapeutic drug. For this purpose, we assessed the coating of a biodegradable ureteral stent, BraidStent^®, with silk fibroin and subsequently loaded the polymeric matrix with two formulations of mitomycin to evaluate its degradation rate, the concentration of mitomycin released, and changes in the pH and the weight of the stent. Our results confirm that the silk fibroin matrix is able to coat the biodegradable stent and release mitomycin for between 6 and 12 h in the urinary environment. There was a significant delay in the degradation rate of silk fibroin and mitomycin-coated stents compared to bare biodegradable stents, from 6–7 weeks to 13–14 weeks. The present study has shown the feasibility of using mitomycin C-loaded silk fibroin for the coating of biodegradable urinary stents. The addition of mitomycin C to the coating of silk fibroin biodegradable stents could be an attractive approach for intracavitary instillation in the upper urinary tract.

Introduction: Priapism is an urological emergency. It consists of an abnormally prolonged erection (>4 hours). It can be differentiated etiologic |