Laparoscopic radiofrequency ablation of small renal tumors: long-term oncologic outcomes.

INTRODUCTION: Unlike percutaneous radiofrequency ablation (RFA) of small renal tumors, there are limited data assessing the long-term efficacy of laparoscopic RFA. Although the ablation cannot be visualized as reliably as with cryoablation, laparoscopic RFA allows for improved mobilization and placement of probes under direct vision. We reviewed our experience with laparoscopic RFA to assess long-term oncologic outcomes. METHODS: We performed a retrospective study of all patients who had undergone laparoscopic RFA for pT1a renal tumors from April 2000 to April 2010. Demographic, clinical, and radiologic data were assessed to determine indications and evidence for recurrence of disease. Radiologic recurrence was defined as any new enhancement (>10 HU) after absence of enhancement on initial negative 6-week computed tomography. RESULTS: Data were available for 79 patients who had 111 small renal masses treated over the 10-year period. The median tumor diameter was 2.2 cm and intraoperative biopsy identified renal cell carcinoma in 77%. The median follow-up was 59 months with an estimated 5-year recurrence-free survival of 93.3%. The overall rate of complications was 8.8% with a 3.8% rate of major complications. CONCLUSIONS: Long-term experience with laparoscopic RFA demonstrates that it is a safe and effective option for the treatment of small renal tumors. Five-year oncologic outcomes appear to be comparable to extirpation.

A comparison of long term renal functional outcomes following partial nephrectomy and radiofrequency ablation.

INTRODUCTION: To compare long term glomerular filtration rate (GFR) outcomes of partial nephrectomy and radiofrequency ablation performed for renal malignancy. MATERIALS AND METHODS: Renal function of 347 patients undergoing radiofrequency ablation (n = 142) or partial nephrectomy (n = 205) for renal malignancy between 1994 and 2011 were compared from a retrospective database at a single tertiary care center. Minimum 1 year of follow up was required, resulting in a mean follow up of 48.2 (SD +/- 28.2) months. Renal function was estimated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. The primary study outcome was progression of Chronic Kidney Disease (CKD) stage, calculated using the Kaplan-Meier life table method. Multivariate analysis was also conducted to determine the level of association between GFR decline and treatment modality. RESULTS: The 5 year freedom from CKD stage progression for radiofrequency ablation and partial nephrectomy was 85.4% (95% CI 76.8%-91.1%) versus 82.1% (95% CI 73.7%-88.1%) (p = 0.06). A longer follow up interval was associated with greater GFR decline, although hypertension, diabetes, age, and tumor size were not. CONCLUSION: Radiofrequency ablation provides similar long term renal function preservation benefit as partial nephrectomy.