Laparoscopic renal cryosurgery: The Northwestern experience

Purpose: Laparoscopic renal cryosurgery provides a minimally invasive alternative for the treatment of small renal lesions of undefined malignant potential. We report on our series of patients treated with laparoscopic renal cryosurgery. Materials and Methods: Fifteen patients underwent laparoscopic renal cryoablation of peripheral, exophytic unifocal renal lesions. Patients were managed with a 4-port transperitoneal approach for anteromedial tumors and 3 to 4-port retroperitoneal approach for posterolateral tumors. All lesions were biopsied and sent to pathology for permanent section. A 4.8 mm cryoprobe (CMS cryoprobe, 4.8 mm x 2 cm x 40 cm, Cryomedical Sciences Inc., Ewing, New Jersey) was placed into the tumor using visual and ultrasonographic guidance, and a double freeze-passive thaw cycle was performed. The iceball was extended at least 1 cm beyond the tumor margin under ultrasound guidance. Followup biopsies were performed on all consenting patients with renal cell carcinoma at least 3 months after cryosurgery was performed. Results: Laparoscopic renal cryosurgery was successfully performed on all 15 patients (6 male and 9 female). Of the 15 patients 10 had renal cell carcinoma. Mean age was 68.5 years (range 49 to 86). Mean tumor size was 2.15 cm (range 1.2 to 3.2) and mean estimated blood loss was 67 cc (range 15 to 125). There were 2 perioperative complications. Mean hospital stay was 3.5 days (range 1 to 11). Patients returned to work after 16.5 days (range 7 to 28). Radiographic follow-up revealed stable cryoablative lesions in all patients. Mean radiographic followup was 453 days (range 147 to 816). Mean preoperative creatinine was 1.25 mg/dl (range 0.8 to 4.3) and mean postoperative creatinine obtained 1 month postoperatively was 1.36 (range 0.8 to 4.8). There was 1 treatment failure, although another patient had a positive biopsy outside the ablated area. The failure occurred in the largest tumor treated (3.2 cm) and was due to incomplete treatment of the periphery of the lesion. The other patient had a successfully treated tumor but a positive followup biopsy due to multifocal papillary renal cell carcinoma and required nephrectomy. Conclusions: Laparoscopic renal cryosurgery appears to be a safe and effective minimally invasive alternative for the treatment of small renal masses. Careful selection of patients with lesions that are less than 3.0 cm and close monitoring of the iceball is necessary to treat these patients successfully.