Laparoscopic-assisted serial biopsy of the bovine kidney.

A serial renal biopsy with endoscopy was done, using 10 calves and a cow. In 8 of the calves, biopsy materials were collected 3 to 5 times over a period of 15 to 41 days. A laparoscope was inserted into the peritoneal cavity from the center of the right paralumbar fossa through the outer cannula of the trocar. Under laparoscopic observation, the renal parenchyma was collected with the cutting prong of a biopsy needle. Of 34 biopsy attempts, 32 were successful; in 2, there was incomplete penetration of the trocar assembly into the peritoneal cavity. In one instance, the trocar was misguided to the small intestine which was closely adherent to the peritoneum. The error may have been the result of the presence of a persistent blood clot resulting from the preceding biopsy. An immediate saline rinse of the blood clot attached to kidney and the surrounding tissues was effective in preventing such adhesions. The size of the average sample obtained was 1.5 mm in diameter and 16 mm (2 to 40 mm) long. The tissues were collected in 61 times from the 72 insertions of the biopsy needle to the renal tissue. The 11 unsuccessful attempts were caused by bluntness of the cutting parts of the needle. Adverse clinical signs were no observed after the serial biopsy of kidney, except for the presence of blood in he urine persisting for 1 to 5 days. Although a dehydrated blood clot was found in the renal pelvis of one animal at necropsy, any complication such as obstruction of urinary flow was not observed.