Improved renal transplantation in the rat with a nonsplinted ureteroureterostomy.

Orthotopic renal transplantation in the rat is a widely used model in immunology and transplantation-related research. Although numerous modifications of the surgical technique of ureteric reconstruction were evaluated, ureter complications following this reconstruction still occurred frequently. Instead of dividing the ureter in the middle between kidney and bladder (method 1), the anastomosis was performed close to the renal pelvis after cutting the ureter obliquely (method 2), which enlarged the diameter of the ureteral anastomosis 2-fold. The incidence of stenosis of ureteric anastomosis was 12.5% (3/24) using method 1, whereas this complication was avoided completely (0/45) using method 2. Furthermore, the risk of injury to the ureter was reduced, as isolation of the ureter was limited. These modifications improved the last delicate step in the procedure of rat kidney transplantation.