The Evaluation of a Dissolvable Ureteral Catheter in a Rabbit Model / 대한비뇨기과학회지

ABSTRACT

PROPOSE Ureteral stents are commonly placed after routine ureteroscopic procedures to prevent acute obstruction. However, stents can cause significant symptoms and they can require a secondary procedure for removal; further, they may possibly be forgotten. In order to overcome these problems, a temporary ureteral drainage stent capable of dissolving spontaneously was developed to evaluate the tissue reaction and toxicity. MATERIALS AND METHODS: We developed a dissolvable ureteral catheter composed of polydioxanone (PDO). We evaluated the toxicity and tissue reaction by hematologic (CBC, aminotransferase/alanine transaminase (AST/ALT), blood urea nitrogen, creatinine (BUN, Cr), alkaline phosphatase) and histologic examination (ureter, kidney and liver tissue). Twelve rabbits were placed into groups of four rabbits each the uninserted control group, group I that had a dissolvable ureteral catheter inserted with harvest at four weeks, group II that had a dissolvable ureteral catheter inserted with harvest at eight weeks, and group III that had a dissolvable ureteral catheter inserted with harvest at twelve weeks. RESULTS: On histologic examination, the ureter had a normal appearance of transitional cells and it contained the dissolvable ureteral catheter in the ureteral lumen without any inflammatory change. The ureteral surface cells appeared normal after contact with the dissolvable ureteral catheter during the 12 weeks. Liver and kidney tissue showed mild focal inflammatory change, but no definitive difference was noted between the control and groups I, II and III. On the hematologic examination, there was no significant change of the value of CBC, AST/ALT, BUN, Cr and alkaline phosphatase due to the inserted dissolvable ureteral catheter during the 12 weeks. CONCLUSIONS: A dissolvable ureteral catheter appeared to have no toxic effect, as evidenced by histological and hematological examination. However, further study is warranted in order to overcome the catheter's limitations like for its flexibility.