Robotic partial nephrectomy versus laparoscopic cryoablation for the small renal mass.

BACKGROUND: Open partial nephrectomy (OPN) remains the gold standard for treatment of small renal masses (SRMs). Laparoscopic cryoablation (LCA) has provided encouraging outcomes. Robotic partial nephrectomy (RPN) represents a new promising option but is still under evaluation.

OBJECTIVE: Compare the outcomes of RPN and LCA in the treatment of patients with SRMs.

DESIGN, SETTING, AND PARTICIPANTS: We retrospectively analyzed the medical charts of patients with SRMs (≤4cm) who underwent minimally invasive nephron-sparing surgery (RPN or LCA) in our institution from January 1998 to December 2010.

INTERVENTION: RPN and LCA.

MEASUREMENTS: Perioperative complications and functional and oncologic outcomes were analyzed.

RESULTS AND LIMITATIONS: A total of 446 SRMs were identified in 436 patients (RPN, n=210; LCA, n=226). Patients undergoing RPN were younger (p<0.0001), had a lower American Society of Anesthesiologists score (p<0.001), and higher baseline preoperative estimated glomerular filtration rate (eGFR) (p<0.0001). Mean tumor size was smaller in the LCA group (2.2 vs 2.4cm; p=0.004). RPN was associated with longer operative time (180 vs 165min; p=0.01), increased estimated blood loss (200 vs 75ml; p<0.0001), longer hospital stay (72 vs 48h; p<0.0001), and higher morbidity rate (20% vs 12%, p=0.015). Mean follow-ups for RPN and LCA were 4.8 mo and 44.5 mo, respectively (p<0.0001). Local recurrence rates for RPN and LCA were 0% and 11%, respectively (p<0.0001). Mean eGFR decrease after RPN and LCA was insignificant at 1 mo, at 6 mo after surgery, and during last follow-up. Limitations include retrospective study design, length of follow-up, and selection bias.

CONCLUSIONS: Both techniques remain viable treatment options in the management of SRMs. A higher incidence of perioperative complications was found in patients undergoing RPN. However, the technique was not predictive of the occurrence of postoperative complications. Early oncologic outcomes are promising for RPN, which also seems to be associated with better preservation of renal function. Long-term follow-up and well-designed prospective comparative studies are awaited to corroborate these findings.