A Single-Institution Experience with Metallic Ureteral Stents: A Cost-Effective Method of Managing Deficiencies in Ureteral Drainage

IntroductionThe limitations of traditional ureteral stents in patients with deficiencies in ureteral drainage have resulted in frequent stent exchanges. The implementation of metallic stents was introduced to improve the patency rates of patients with chronic upper urinary tract obstruction, obviating the need for frequent stent exchanges. We report our clinical experiences with the use of metallic ureteral stents in the management of poor ureteral drainage.Materials and MethodsFifty patients underwent metallic ureteral stent placement from 2009 to 2012. Stent failure was defined as an unplanned stent exchange, need for nephrostomy tube placement, increasing hydronephrosis with stent in place, or an elevation in serum creatinine. Stent life was analyzed using the Kaplan-Meier methodology, as this was a time dependent continuous variable. A cost analysis was similarly conducted.ResultsA total of 97 metallic stents were placed among our cohort of patients: 63 in cases of malignant obstruction, 33 in the setting of cutaneous ureterostomies, and 1 in an ileal conduit urinary diversion. Overall, stent failure occurred in 8.2% of the stents placed. Median stent life was 288.4 days (95% CI: 277.4-321.2 days). The estimated annual cost for traditional polymer stents (exchanged every 90 days) was $9,648-$13,128, while the estimated cost for metallic stents was $4,211-$5,313.ConclusionOur results indicate that metallic ureteral stent placement is a technically feasible procedure with minimal complications and is well tolerated among patients. Metallic stents can be left in situ for longer durations and provide a significant financial benefit when compared to traditional polymer stents.

Development and manufacture of prosthetic cardiac valves: mexican cardiac valvular prostheses / Desarrollo y fabricación de prótesis cardiacas valvulares: prótesis cardicadas valvulares mexicanas

Se expone un relato histórico sucinto del desarrollo de la fabricación de las prótesis valvulares cardiacas. Se analiza el uso que han tenido estas prótesis, describiendo las fases sucesivas del uso de los distintos tipos de válvulas mecánicas de prótesis, en particular la experiencia con su implantación en México. Se relata el proceso de manufactura, pruebas de funcionamiento y resultados clínicos obtenidos con las válvulas Biomed hechas en México. Se concluye que estas prótesis cumplen con las normas más altas y que en vista de su bajo costo, son la mejor opción para ser implantadas en pacientes de nuestro país