Laparoscopic Renal Tumor Cryoablation: Appropriate Application of Real-Time Ultrasonographic Monitoring

Abstract

Many authors who report outcomes of laparoscopic cryoablation for renal tumors comment that real-time intracorporeal ultrasonographic monitoring of the ice-ball formation is imperative. In our experience, ultrasonographic monitoring of the ice-ball formation necessitates significantly more mobilization of the kidney, and the images are difficult to interpret because of artifact and the cryoablation effect on the tissue. We report our intermediate outcomes for laparoscopic cryoablation without real-time ultrasonographic monitoring of the ice ball. Between December 2002 and May 2007, 27 patients underwent laparoscopic renal cryoablation. The cryoablation approach was based on tumor location and surgeon preference. Lesions were identified and overlying fat was excised, without further mobilization. Real-time ultrasonographic measurement and mapping of the renal lesion were performed. All lesions were biopsied before cryoablation. A double 10-minute freeze-thaw cycle was performed. Postoperative follow-up comprised serial imaging at months 1, 3, 6, and 12 and yearly thereafter. Mean patient age was 70.1 years with a mean renal tumor size of 2.2 cm. Sixteen (59.3%) patients had more than three comorbidities and six (22.2%) patients had two comorbidities with at least 1 previous intra-abdominal surgery. An average of four cryoablation probes were used per lesion. The serum creatinine level was 1.3 mg preoperatively and 1.4 mg at last follow-up. At follow-up of 22 months, there were no local recurrences and 1 (3%) metastatic lesion. Laparoscopic cryoablation of small renal masses continues to be a safe and effective technique, even without the use of real-time ultrasonographic monitoring of the ice ball.