Laparoscopic cryoablation for small renal masses: three-year follow-up.

OBJECTIVES

To report our experience with laparoscopic renal cryoablation for patients who have completed a minimum of 3 years of follow-up.

METHODS

From July 2000 to March 2005, 81 patients underwent laparoscopic renal cryoablation for renal masses. Of these 81 patients, 31 (38%) underwent laparoscopic renal cryoablation for 36 tumors and have completed a minimal follow-up of 3 years (mean 45.7 months). The postoperative follow-up protocol consisted of serial contrast-enhanced computed tomography or magnetic resonance imaging at 1 day, 1, 3, 6, and 12 months, and yearly thereafter.

RESULTS

Twenty-seven tumors were partially exophytic, five were totally endophytic, and four were hilar tumors. The mean operative time was 2.9 hours, with a mean estimated blood loss of 97 mL. The mean renal tumor size was 2.1 cm. In early follow-up, the ablation zone was larger than the tumor but subsequently diminished to the original tumor size 6 months postoperatively. Thereafter, the ablation zone size decreased. The biopsy results revealed that 22 tumors (61%) were malignant and 14 (39%) were benign. The renal tumor 3-year cancer-specific survival rate was 100%, and no patient developed metastatic disease. One patient demonstrated return of abnormal enhancement within the cryolesion during follow-up, suggesting tumor recurrence. One patient had a hemorrhage and urinary leak after cryoablation of an endophytic tumor and was treated conservatively.

CONCLUSIONS

Renal cryoablation is safe and offers a minimally invasive nephron-sparing alternative. The oncologic adequacy of renal cryoablation requires long-term follow-up data, but the intermediate-term data seem equivalent to that achieved with extirpative therapy.