Abstract:

BACKGROUND: The presently used ureteral stent are made of undegradable silicone and polyurethane, which must be removed by operation after a certain period of implantation.
OBJECTIVE: To observe the pathologic changes of canine ureter caused by poly-DL-lactic acid stent and polyurethane stent.
METHODS: Poly-DL-lactic acid and polyurethane stents were implanted in different sides of canine ureters by operation. Ureteral incision specimens were obtained every two weeks. The pathologic changes of canine ureter were observed under light microscope.
RESULTS AND CONCLUSION: Traumatic inflammation was the main pathological change of all ureteral specimens. Epithelial decortication, edema of the proper layer and disarrangement of the muscle layer were obvious at the second and the fourth weeks. The arteriolar congestion in proper layer was found at the sixth week. There was no significant disorder at the end of eighth week. The result demonstrated that Poly-DL-lactic acid stent has fairly good tissue compatibility.