Category: Clinical Stones: Equipment (stents, lasers, guidewires, sheaths)

MP27-12 - Assessment of biodegradable, heparin-coated anti-reflux micro-stent. Animal study.

Sun, Sep 23
10:00 AM - 12:00 PM

Introduction & Objective :

Ureteral stents have been part of urology for over fifty years and have proven to be a perfect tool for urolithiasis, to manage urinary leak, to relieve ureteral obstruction, and to promote ureteral healing as scaffolds. However, they are associated with high morbidity, thus reducing patients' quality of life. Current ureteral stents also need a second procedure for their removal. Our objective in this experimental study is assessment of a biodegradable intraureteral stent with a new design of heparin-coated antimigration system (BraidStent).

Methods :

We used 36 swine animal models. After baseline evaluation of the urinary tract by fluoroscopy, ultrasonography, blood and urinalysis, study was initiated with the measurement of the UPJ diameter, simulated voiding cystourethrography to assess vesicoureteral reflux (VUR), ureteral peristalsis and evaluation of damage to the ureteral orifice. Animals were distributed in 3 homogeneous groups: Group-I, unilateral stenting of the BraidStent (3Fr); Group-II, iatrogenic ureteral perforation model and BraidStent stenting; Group-III, ureteral stricture model, with laser endoureterotomy treatment and BraidStent stenting. The follow-ups were carried out at 1, 3 and 6 weeks and the final follow-up at 5 months, using the diagnostic techniques mentioned above. During follow-ups: internal diameter of the UPJ, urinoma, VUR, migration, ureteral peristalsis, urothelial hyperplasia, and obstructive effects of the stent fragments were assessed.

Results :

None of the animals showed VUR at any phase of the study. We found statistical significance (SS) in the evolution of UPJ diameter (passive ureteral dilation) between the baseline study and the follow-ups, but not between groups. The overall BraidStent migration rate was 16.6% at 3 weeks. The positive urine culture rate was 46%. BraidStent completes its degradation in all cases between 3 and 6 weeks, without evidence of obstructive fragments. The overall maintenance rate for distal ureteral peristalsis at BraidStent was 80.3% at 6 weeks. The success rate in Group II was 95.8% and Group III was 83%.

Conclusions :

BraidStent biodegradable stent shows a predictable biodegradation rate (3-6 weeks), with no formation of obstructive fragments in its hydrolytic degradation process. Showing that ureteral intubation is only necessary in the ureteral healing segment. Therefore, their tolerance in patients will be presumably better than the current ureteral stents.

Federico Soria

Endoscopy-Endourology Coordinator
Minimally Invasive Surgery Centre Jesus Uson. Spain
caceres, Extremadura, Spain

Dr. Federico Soria. Chairman. ENIUS (European network of multidisciplinary research to improve the urinary stents. European Cooperation in Science &Technology. Framework Programme Horizon 2020). (

Dr. Federico Soria is Endoscopy Coordinator in Jesus Uson Minimally Invasive Surgery Centre (Spain) a multidisciplinary institution devoted to Research, Innovation and Training in health sciences.
Dr. Soria research is focused on Traslational Research (Preclinical) Minimally Invasive Surgery Urological techniques and devices. A special focus area is urinary tract stents design: Biodegradable, Drug eluting stents and metallic designs and Biomaterials. Researcher in more than 30 research projects, 16 as a principal investigator. Three patents in Biomedicine devices (ureteral stents).

Julia E. de la Cruz

Caceres, Extremadura, Spain

Alvaro Serrano

Madrid, Madrid, Spain

Alberto Budia

Valencia, Comunidad Valenciana, Spain

Marcos Cepeda

Urologist, Endourology and Laparoscopy Unit
Hospital Universitario Río Hortega, Valladolid, Spain
Valladolid, Castilla y Leon, Spain

Daniel Perez-Fentes

Santiago de Compostela Hospital, Urology, Santiago de Compostela, Spain
Santiago de Compostela, Galicia, Spain

Francisco Sánchez Margallo

Caceres, Extremadura, Spain