The study plan utilized a total of 10 pigs for a total of 10 days, with 7 in the experimental BUS group and 3 in the control commercial ureteral stent group. Blood and urine analysis were done before placement. Intravenous pyelogram (IVP) was used to determine if urine drainage was affected, and X-ray was used to check stent placement throughout the trial. On the 5th day, some of the BUS and urinary tracts were extracted from the pigs to evaluate homogenous degradation and if the BUS was fragmented.
Following the study, a microbial urine analysis was conducted. For the experimental BUS group, they found sterile cultures throughout all 10 days. For the control commercial group, there were positive cultures starting at the 5th day. From the histopathological analysis, they found the BUS caused less stent effects, with the ureteral epithelium remaining intact, similar to a non-stented ureter. For the commercial stent, incidences of hydronephrosis, edema, and epithelium destruction were found. In regards to fragmentation evaluation, no BUS fragments were found in the renal pelvis, ureter, or bladder.
Dr. Barros concluded that the results supported their hypothesis of the hydrogel biodegradable ureteral stent exhibiting homogenous degradation by surface erosion. A future direction him and his team proposed was to begin clinical trials for patients to evaluate further the clinical use and potential to reduce ureteral injury.
Presented by: Alexandre Barros, MD
Written by: Cyrus Lin, Department of Urology, University of California-Irvine at the 2018 AUA Annual Meeting - May 18 - 21, 2018 – San Francisco, CA USA