Laparoscopic renal cryoablation using ultrathin 17-auge cryoprobes : mid-term oncological and functional results

OBJECTIVE To present the functional and oncological mid-term results of laparoscopic cryoablation of renal masses using third generation ultrathin (17-gauge[G]) cryoprobes. PATIENTS AND METHODS • Consecutive patients with small renal masses treated by cryoablation from September 2003 to September 2008 were prospectively evaluated. The cryoablation was performed using multiple third generation 17-G cryoprobes after intraoperative mass biopsy. • Data on serum creatinine measurements and cross sectional imaging (computed tomography/magnetic resonance imaging) were regularly collected according to a previously determined protocol. Follow-up was censored in October 2009. • Renal function analysis was based on estimated glomerular filtration rate (eGFR) at 1 year compared with baseline. Residual (or persistent tumour) and recurrence were defined as the presence of residual enhancement at first follow-up and ‘de novo’ enhancement of a non-enhancing cryolesion at any time during follow-up. • Survival data were analysed using the Kaplan–Meier method. Best estimates for the overall survival (OS), recurrence-free survival (RFS), cancer-specific survival (CSS) and metastatic-free survival (MFS) were made for patients with renal cell carcinoma (RCC) and for patients with RCC or non-diagnostic biopsy. RESULTS • A total of 92 patients (100 tumours; mean size 2.5 ± 0.8 cm) were treated in 95 sessions. The mean follow-up was 30.2 ± 16.6 months (Mean values are ±SD). • Intraoperative biopsy showed RCC in 51 patients (53.7%), benign lesion in 23 patients (24.2%) and was non-diagnostic in 21 patients (22.1%). Three tumour persistences and four radiological recurrences were detected. • The estimated mean RFS time and 3-year OS and RFS in patients with RCC exclusively were 47.8 (95% confidence interval [CI]: 44.1–51.1) months, 86.1% (95% CI: 71.2–93.6) and 91.8% (95% CI: 76.3–97.3), respectively. The figures were slightly higher in the group of patients with RCC or unknown pathology. The actual CSS and MFS rates were 100%. • Renal function was preserved in 84.5% of patients with normal preoperative eGFR. • Baseline eGFR was the only predictor of renal insufficiency development at 1-year follow-up. CONCLUSION Laparoscopic cryoablation with multiple ultrathin cryoprobes is oncologically and functionally effective at mid-term follow-up.