Laparoscopic cryoablation of renal masses: which lesions fail?

Objective: To identify potential predictive characteristics of lesions which failed in laparoscopic renal cryoablation (LRC). We analyzed 47 lesions that underwent this approach.

Methods: We reviewed 45 consecutive patients who underwent LRC of a renal mass between 2003 and 2008 at a single institution. A total of 47 masses were identified; all were treated by 2 surgeons. We analyzed patient age, ASA, pre- and postoperative creatinine, tumor size, location, number of cryoprobes used, and histology of the lesions. We reviewed imaging to identify characteristics of those lesions which failed LRC management, defined as lesions that demonstrated persistent enhancement and/or did not decrease in size within 6 months of therapy.

Results: A total of 47 lesions in 45 patients were identified. The median follow-up was 13 months. Mean lesion size was 2.7 cm (range, 1.2-5.4), with 25 anterior and 22 lateral or posterior lesions. Of the biopsy samples from 40 of 47 lesions, renal cell carcinoma was found in 23, oncocytoma was found in 7, and 10 were benign or inconclusive. Treatment failure was noted in 8 of 47 lesions (17%), 7 of which (87.5% of failed lesions) had broad-based contact with the renal sinus. Broad-based lesions which made contact with the renal sinus were successfully treated 53.3% of the time, whereas lesions which lacked contact with the renal sinus were treated successfully 96.9% of the time (P <.01).

Conclusions: Broad-based central location of a renal mass may predict a significantly increased risk of failure of LRC and should be considered in patient counseling.