LAPAROSCOPIC CRYOSURGERY OF THE KIDNEY IN THE PORCINE MODEL - AN ACUTE HISTOLOGICAL STUDY

Objectives. To verify histologically whether cryosurgery of the kidney can be accomplished reproducibly without injuring adjacent structures , using a combination of ultrasound and laparoscopic guidance. Materia ls and Methods. Six kidneys from three domestic female farm pigs were utilized in the study. Under general anesthesia and after obtaining pn eumoperitoneum, the lower pole of the kidney was mobilized laparoscopi cally and the ureter and adjacent bowel were protected with saline-soa ked gauze. Two 3.8 mm-cryoprobes were placed percutaneously into the l ower pole and cryoablation was carried out under laparoscopic and ultr asound guidance using a double-freeze technique (10-minute freeze and 5-minute thaw cycles to a probe temperature of -185 degrees C to -196 degrees C) in five kidneys (one control). The kidneys, adjacent ureter and bowel were harvested acutely, and macroscopic, histologic, and el ectron microscopic evaluation of all specimens was performed. Results. Macroscopically, clear margins of cryodestruction corresponded with t he ultrasound images of the iceball. In all five treated kidneys, repr oducible cell death corresponding to visible margins of cryodestructio n were verified histologically. Cell death was further corroborated by electron microscopy. Adjacent structures (ureter and bowel) were sect ioned and no significant damage was noted. Blood pressure remained con stant throughout the procedure. A crack in the renal parenchyma of one kidney was noted during the thaw phase; at harvest that animal was fo und to have an intraperitoneal hemorrhage. Conclusion. Combined laparo scopic and ultrasound-guided cryoablation of the lower pole of the kid ney can be accomplished reproducibly in the porcine model without inju ry to adjacent structures. (C) 1998, Elsevier Science Inc. All rights reserved.