Minimally Invasive Partial Nephrectomy Versus Laparoscopic Cryoablation for Patients Newly Diagnosed with a Single Small Renal Mass

Background: Minimally invasive partial nephrectomy (MIPN) and laparoscopic renal cryoablation (LRC) are two treatment options increasingly used for small renal masses. Objective: To compare perioperative, oncologic, and functional outcomes after MIPN and LRC. Design, setting, and participants: We included 372 consecutive patients newly diagnosed with a single small renal mass and treated with either MIPN or LRC at a single institution. Intervention: MIPN and LRC. Outcome measurements and statistical analysis: Regression models were used to evaluate the impact of surgical treatment (MIPN vs LRC) on perioperative, oncologic, and functional outcomes. Results and limitations: Overall, 206 patients (55%) underwent MIPN and 166 (45%) were treated with LRC. In multivariate analysis, the rate of postoperative complications was significantly lower in the MIPN compared to the LRC group (20% vs 28%; adjusted difference -11%; p= 0.02) after adjusting for age at surgery, American Society of Anesthesiologists score (1 vs 2 vs 3), and tumor size. The median follow-up was similar in the two groups (43 and 39 mo for MIPN and LRC, respectively). In univariate Cox regression analysis, treatment type was not significantly associated with disease-free survival (hazard ratio 1.06, 95% confidence interval [CI] 0.45-2.52; p= 0.9). The disease-free survival rate at 5 yr was 92% in MIPN and 93% in LRC patients. In multivariate linear regression analysis, LRC was significantly associated with a higher estimated glomerular filtration rate (eGFR) at 6 mo compared to MIPN (coefficient 4.68, 95% CI 0.06-9.30; p= 0.047) after adjusting for age at surgery, tumor size, and preoperative eGFR. There was no significant association between surgical treatment and postoperative eGFR at 3 yr after surgery (coefficient -2.36, 95% CI -7.55 to 2.83; p= 0.4). Limitations include the retrospective study design and selection bias. Conclusions: MIPN and LRC provided similar cancer control and comparable renal function at intermediate-term follow-up. Both surgical techniques emerged as viable treatment options for patient newly diagnosed with a single small renal mass. Further multi-institutional studies with longer follow-up and nephrometry scores are needed to corroborate our findings. Patient summary: In patients newly diagnosed with a single small renal mass, minimally invasive partial nephrectomy and laparoscopic renal cryoablation provided similar cancer control and comparable renal function at intermediate-term follow-up.