Comparative assessment of biodegradable-antireflux heparine coated ureteral stent: animal model study.
BACKGROUND
Double J ureteral stents are widely used on urological patients to provide drainage of the upper urinary tract. Unfourtunately, ureteral stents are not free from complications, as bacterial colonization and require a second procedure for removal. The purpose of the current comparative experimental study is to evaluate a new heparin-coated biodegradable antireflux ureteral stent (BraidStent®-H) to prevent urinary bacterial colonization.


METHODS
A total of 24 female pigs were underwent determination of bacteriuria and nephrosonographic, endoscopic and contrast fluoroscopy assessment of the urinary tract. Afterward, were randomly assigned animals to Group-I, in which a 5Fr double-pigtail ureteral stent was placed for 6 weeks, or Group-II, in which a BraidStent®-H was placed. Follow-up assessments were performed at 1, 3, 6, 8, 12 weeks. The final follow-up includes the above methods and an exhaustive pathological study of the urinary tract was accomplished after 20 weeks.


RESULTS
Bacteriuria findings in the first 48 h were significant between groups at 6 h and 12 h. Asymptomatic bacteriuria does not reach 100% of the animals in Group-II until 48 h versus Group-I where it appears at 6 h. The weekly bacteriuria mean rate was 27.7% and 44.4% in Group I and II respectively, without statistical significance. In Group II there were no animals with vesicoureteral reflux, with statistical significance at 3 and 6 weeks with Group-I. The 91.2% of stents in Group-II were degraded between 3 and 6 weeks, without obstructive fragments. Distal ureteral peristalsis was maintained in 66.6-75% in Group-II at 1-6 weeks.


CONCLUSIONS
The heparin coating of BraidStent® allows an early decrease of bacterial colonization, but its effectiveness is low at the long term. Heparin coating did not affect scheduled degradation rate or size of stents fragments. BraidStent®-H avoids the side effects associated with current ureteral stents, thus should cause less discomfort to patients.
['Soria|Federico|F|', 'de La Cruz|Julia E|JE|', 'Caballero-Romeu|Juan Pablo|JP|', 'Pamplona|Manuel|M|', 'Pérez-Fentes|Daniel|D|', 'Resel-Folskerma|Luis|L|', 'Sanchez-Margallo|Francisco M|FM|']
D020341:Absorbable Implants D000818:Animals D001437:Bacteriuria D004195:Disease Models, Animal D054855:Drug-Eluting Stents D005260:Female D006493:Heparin D011897:Random Allocation D013552:Swine D014513:Ureter D014718:Vesico-Ureteral Reflux
Heparin coated Antireflux stents Biodegradable ureteral stent Biofilm Morbidity