Paranephric water instillation: a technique to prevent bowel injury during percutaneous renal radiofrequency ablation.

A 45-year-old woman with von HippelLindau disease was referred for the treatment of two solid enhancing left renal masses noted on CT. She had a history of bilateral partial nephrectomies for multiple renal cell carcinomas. One of the lesions measured 1.5 cm in diameter and was in the anterior mid kidney adjacent to the descending colon. Sterile water (135 mL) was instilled into the tissues between the anterior aspect of the kidney and the adjacent descending colon using a 21-gauge spinal needle under sonographic guidance. This resulted in the bowel being displaced approximately 2.5 cm from the anterior aspect of the renal tumor. The tumor was then treated for 12 min with a 2-cm single-tip active electrode using the Radionics system (Burlington, MA). Contrast-enhanced CT performed 4 hr after the procedure showed complete ablation of the tumor and no evidence of bowel injury. Repeated CT 2 months after ablation showed no evidence of residual or recurrent tumor, and the adjacent bowel had a normal appearance.