We evaluated 11 currently available biopsy devices using a standard and a novel renal biopsy technique in a porcine model. We then applied our laboratory findings to clinical practice to improve our biopsy results during laparoscopic renal cryoablation procedures.

A total of 11 biopsy devices were applied to live porcine renal tissue using two different techniques. In groups 1 and 2, the biopsy devices were deployed external to the renal tissue and in a standard manner after insertion into the renal tissue, respectively. Ten biopsies were performed for each condition and with each device. The biopsy quality metrics included sample core length and width and number of glomeruli and vessels in each sample. Subsequently, we confirmed our laboratory finding regarding the optimal biopsy technique during 10 sequential laparoscopic renal cryoablation procedures. During these procedures, each renal mass underwent the standard and modified biopsy techniques.

In the animal investigation, a total of 220 biopsies were performed. Regarding the biopsy technique, the mean core length for groups 1 and 2 was 7.32 and 4.91 mm (P <0.01) and the mean number of glomeruli was 7.6 and 4.2 (P <0.01), respectively. Clinically, 10 patients successfully underwent renal cryoablation in conjunction with the two renal biopsy groups. In all 10 cases, between the two biopsies, a histopathologic diagnosis was successfully obtained. The preablation standard and preablation modified biopsy technique established a diagnosis 7 of 10 and 9 of 10 times, respectively.

Our preliminary laboratory and clinical data have demonstrated the effectiveness and safety of the modified biopsy technique.