Renal Function and Oncologic Outcomes after Cryoablation or Partial Nephrectomy for Tumors in Solitary Kidneys

Purpose: Preservation of renal function is of paramount importance in patients with tumors in solitary kidneys. We compared the renal function and oncologic outcomes of patients treated by partial nephrectomy with those of patients treated by cryoablation for solitary kidney tumors. Materials and Methods: All patients with solitary kidneys who were treated for renal tumors at our institution between 1997 and 2007 were included in the screen. We retrospectively identified 23 patients who underwent cryoablation and 15 patients who underwent partial nephrectomy. Results: The two groups were similar with regard to age, gender, and tumor laterality. Patients in the partial nephrectomy group had a larger tumor size (3.4 cm vs. 2.5 cm, p=0.01), higher mean estimated blood loss (316 cc vs. 87 cc, p<0.001), longer duration of hospital stay (5.8 vs. 1.8 days, p<0.001), and a higher rate of perioperative complications (53.3% vs. 8.7% patients, p=0.03). Percentage changes in the glomerular filtration rate postoperatively and on follow-up were found to be similar in the two groups. Both the cryoablation and the partial nephrectomy groups with mean follow-ups of 31.2 months and 30.8 months, respectively, had evidence of local or distant recurrence in 3 patients each (13% and 20% respectively, p=0.7). Both groups had a similar mean overall survival (88.9 and 86.9 months in the cryoablation and partial nephrectomy groups, respectively, p=0.8). Conclusions: For tumors in solitary kidneys, renal functional and clinical outcomes for cryoablation were not significantly different from those for partial nephrectomy. However, cryoablation has the distinct advantage of a lower morbidity rate and can be preferentially offered to selected cases.