To compare percutaneous renal cryoablation complications and outcomes in obese and morbidly obese vs nonobese patients.

Three hundred eighty-nine percutaneous cryoablation procedures were performed in 367 patients for treatment of 421 renal masses at our institution between 2003 and 2012. Patients were categorized into 3 groups on the basis of body mass index (BMI): nonobese (BMI <30.0 kg/m²), obese (BMI 30.0-39.9 kg/m²), and morbidly obese (BMI ≥40.0 kg/m²). Each group was retrospectively analyzed for major complications (Clavien ≥grade 3) and oncologic outcomes.

One hundred eighty-nine renal cryoablation procedures (48.6%) were performed on nonobese patients, 161 (41.4%) on obese patients, and 39 (10.0%) on morbidly obese patients. Eleven (5.8%) major complications occurred in nonobese patients, 15 (9.3%) in obese patients, and 3 (7.7%) in morbidly obese patients. As such, there was no significant difference in the rate of major complications in obese (P = .23) or morbidly obese (P = .67) compared with nonobese patients. There was 1 ablation-related death from complications of urosepsis. Thirteen local treatment failures were identified, including 5 technical failures and 8 local tumor recurrences during median imaging follow-up of 18 months (interquartile range: 8-36). Six local treatment failures (3.2%) occurred in nonobese patients, 5 (2.9%) in obese patients, and 2 (4.8%) in morbidly obese patients. Again, no significant difference was noted in local treatment failure rate between obese (P = .96) or morbidly obese (P = .57) compared with nonobese patients.

Percutaneous renal cryoablation complication rates and short-term outcomes in obese and morbidly obese patients are similar to those in nonobese patients.