2012 February | endourology.com

Laparoscopic vs. Percutaneous Radio Frequency Ablation of Renal Masses

Feb 282012

Comparison of Safety, Renal Function Outcomes and Efficacy of Laparoscopic and Percutaneous Radio Frequency Ablation of Renal Masses

Young E. E., Castle S. M., Gorbatiy V. and Leveillee R. J.

J Urol (2012)

PURPOSE: With the increased incidence of low stage renal cancers, thermal ablation technology has emerged as a viable treatment option. Current AUA (American Urological Association) guidelines include thermal ablation as a treatment modality for select individuals. We compared the laparoscopic and percutaneous approach for the radio frequency ablation of renal tumors under the guidance of urological surgeons.

MATERIALS AND METHODS: We reviewed our radio frequency ablation database of patients with renal masses undergoing laparoscopic or computerized tomography guided percutaneous radio frequency ablation with simultaneous peripheral fiberoptic thermometry from November 2001 to January 2011 at a single tertiary care center. Data were collected on patient demographics, and surgical and clinicopathological outcomes stratified by approach.

RESULTS: A total of 298 patients with 316 renal tumors underwent laparoscopic (122 tumors) or computerized tomography guided (194 tumors) radio frequency ablation. There were no statistically significant differences between the laparoscopic and computerized tomography guided radio frequency ablation groups with respect to patient demographics, complication rates and renal functional outcomes (p >0.05). The 3-year Kaplan-Meier estimation of radiographic recurrence-free probability was 95% for computerized tomography guided radio frequency ablation and 94% for laparoscopic radio frequency ablation (p = 0.84). Subanalysis of the 212 (67%) renal cell carcinoma tumors showed a 3-year Kaplan-Meier estimation of oncologic recurrence-free probability (post-ablation biopsy proven viable tumor) of 94% for computerized tomography guided radio frequency ablation and 100% for laparoscopic radio frequency ablation (p = 0.16). Median followup was 21 months for laparoscopic radio frequency ablation) and 19 months for computerized tomography guided radio frequency ablation.

CONCLUSIONS: Laparoscopic and computerized tomography guided radio frequency ablation appear safe and effective with statistically equivalent rates of complications and recurrence

Commentary:

Encouraging results for RFA from a group with a great deal of experience. It appears from this data we can choose either percutaneous (when feasible) or laparoscopic based upon tumor location, without concern for significant difference in outcomes. Unfortunately, we still have no randomized trials of ablative therapy for small renal masses.

Focused ultrasound to expel calculi from the kidney.

urolithiasis No Responses »

Feb 222012

Shah A., Harper J. D., Cunitz B. W., Wang Y. N., Paun M., Simon J. C., Lu W., Kaczkowski P. J. and Bailey M. R.

J Urol 187(2):739-43 (2012)

PURPOSE: A persistent stone burden after renal stone treatment may result in future patient morbidity and potentially lead to additional surgery. This problem is particularly common after treatment of lower pole stones. We describe a potential noninvasive therapeutic option using ultrasound waves to create a force sufficient to aid in stone fragment expulsion.

MATERIALS AND METHODS: Human stones were implanted by retrograde ureteroscopy or antegrade percutaneous access in a live porcine model. The calibrated probe of a system containing ultrasound imaging and focused ultrasound was used to target stones and attempt displacement. To assess for injury an additional 6 kidneys were exposed for 2 minutes each directly to the output used for stone movement. Another 6 kidneys were exposed to more than twice the maximum output used to move stones. Renal tissue was analyzed histologically with hematoxylin and eosin, and nicotinamide adenine dinucleotide staining.

RESULTS: Stones were moved to the renal pelvis or ureteropelvic junction by less than 2 minutes of exposure. Stone velocity was approximately 1 cm per second. There was no tissue injury when tissue was exposed to the power level used to move stones. Localized thermal coagulation less than 1 cm long was observed in 6 of 7 renal units exposed to the level above that used for ultrasonic propulsion.

CONCLUSIONS: Transcutaneous ultrasonic propulsion was used to expel calculi effectively and safely from the kidney using a live animal model. This study is the first step toward an office based system to clear residual fragments and toward use as a primary treatment modality in conjunction with medical expulsive therapy for small renal stones

Comment:

Very interesting preliminary work in an animal model. Could external energy like this facilitate ureteroscopic or percutaneous treatment? Perhaps we could move fragments out of the lower pole, or move small fragments out of the kidney during the procedure, eliminating the need to pass them later. It might be possible to avoid a second puncture, or move that elusive fragment into the renal pelvis during percutaneous nephrolithotomy. I look forward to updates from the UW group.