Laparoscopic microwave ablation and enucleation of small renal masses: preliminary experience

Advancements in imaging and laparoscopy have led to the expansion of minimally invasive techniques in the ablation of small renal masses (SRMs). We report the results of a study aimed at assessing the efficacy of thermoablative microwave (MW) effects on SRMs and the haemostatic as well as necrotic MW effects on the parenchyma surrounding the neoplasm. From November 2008 to October 2010, 10 patients with SRMs underwent laparoscopy-guided Tru-Cut biopsy, MW tumour ablation, and enucleation. Mean age was 66 yr (range: 46-84 yr). Mean renal tumour diameter was 2.75 cm (range: 1.3-4.2 cm). MW antennas were applied one to three times depending on tumour volume, location, and shape. After MW thermoablation, laparoscopic enucleation was performed to evaluate the histopathologic and haemostatic effects of MW. The mean MW antenna application time was 14.1 min (range: 4-30 min). Enucleation did not require renal pedicle clamping in any of the cases because no significant bleeding took place. Preablation pathology revealed clear cell renal carcinoma of Fuhrman grade I-II in all cases. Postablation pathology showed extensive coagulative necrosis without skipped tumour areas. No intra- or postoperative complications were reported. Histopathologic effects on SRMs provide consistent proof of principle for future studies.