Objective: To compare diagnostic quality of percutaneous kidney biopsy specimens obtained with laparoscopy versus ultrasound guidance in dogs and compare diagnostic quality of specimens obtained with 14- versus 18-gauge biopsy needles.
Design: Prospective study.
Animals: 10 healthy dogs.
Procedure: In each dog, 2 biopsy specimens were obtained from each kidney, 1 with a 14-gauge biopsy needle and 1 with an 18-gauge biopsy needle. Biopsy specimens were obtained from 1 kidney by means of ultrasound guidance and from the contralateral kidney by means of direct viewing during laparoscopy. Number of glomeruli, quality of the biopsy specimen, proportion of specimens that contained muscle tissue, and proportion of specimens with fragmentation or crushing were determined.
Results: Mean +/- SD number of glomeruli (32.6 +/- 11.0) in laparoscopic, 14-gauge biopsy specimens was significantly higher than mean number of glomeruli in ultrasound-guided, 14-gauge specimens; mean number of glomeruli in ultrasound-guided, 18-gauge specimens; and mean number of glomeruli in laparoscopic, 18-gauge specimens. All 10 laparoscopic, 14-gauge biopsy specimens were classified as excellent. The proportion of 18-gauge biopsy specimens with crushing or fragmentation was significantly higher than the proportion of 14-gauge specimens. One of the kidneys biopsied with ultrasound guidance had a large amount of hemorrhage. Hemorrhage was modest and transient following laparoscopic biopsy.
Conclusions and clinical relevance: Results suggest that excellent-quality renal biopsy specimens with large numbers of glomeruli can be obtained with 14-gauge, double-spring-activated biopsy needles during laparoscopy. Renal biopsy specimens obtained with 18-gauge biopsy needles frequently had few glomeruli and often were crushed or fragmented, increasing the difficulty in making an accurate diagnosis.