Microsurgery of resection and anastomosis of a circumcaval ureter with focal stenosis in a feline: case report

ABSTRACT The circumcaval ureter, a rare venous anomaly, results from abnormal embryonic development of the posterior cardinal vein and often leads to ureteral obstruction and hydronephrosis, particularly in felines. This case report aims to describe a microsurgical resection and ureteral anastomosis performed on a feline with circumcaval ureteral stenosis causing focal obstruction and severe right hydronephrosis. The methodology involved ultrasonographic diagnosis, preoperative stabilization with medical therapy, and a high-precision surgical intervention under microscopy to excise the stenotic segment and restore ureteral continuity. Postoperative evaluations included imaging and hematologic monitoring, revealing a progressive reduction in ureteral dilation but irreversible loss of right kidney function, necessitating a nephrectomy. This work highlights the technical challenges and potential outcomes of microsurgical management of ureteral anomalies in small animals.