Percutaneous US-guided renal cryoablation using 3D modeling

The article describes the first experience of performing percutaneous ultrasound (US)-guided cryoablation of renal tumor and assesses the safety and short-term results of treatment.

Twelve patients were subjected to US-guided cryoablation of renal tumor in 2015. The tumor size in 11 patients was up to 3.0 cm (T1а); in one female patient, 4.5 cm (T1b). Tumors were assessed according to the PADUA score. In eight patients, it was 6-7 (low); in three patients, 8-9 (average); in one, 10 (high). All the patients underwent US examination using a FlexFocus 800 apparatus with convex abdominal transducers. Before surgery and 6 months later, all the patients underwent renal Doppler US and contrast-enhanced computed tomography.

The average cryoablation time was 60 min. Seven operations were performed under spinal anesthesia and five operations under local anesthesia. The follow-up period lasted 8 months on average. According to the ultrasonography and Doppler findings, after 6 months, the tumor (T1a) in 11 patients reduced in size by an average of 7-8 mm and had no blood supply.T1b patient's mass size reduces from 4.5 to 3.7 cm; however, a 1.5 cm area with a high attenuation gradient of the contrast medium was visualized. Later, the patient was subjected to laparoscopic renal resection. Histological finding revealed clear-cell carcinoma.

We consider percutaneous US-guided cryoablation as a method of choice for patients with stage T1a renal tumor localized on the posterior or lateral surface in the inferior or middle segment without sinus involvement and PADUA <9.