New findings from the large, multicentre IRON study demonstrate that robot-assisted partial nephrectomy (RAPN) is associated with lower morbidity and similar oncologic and long-term renal function outcomes compared with open partial nephrectomy (OPN).
Dr. Alessandro Larcher (Ospedale San Raffaele, Milan, Italy) presented the large, multi-institutional analysis of clinical outcomes after RAPN or OPN at 9 high-volume European, North American, and Asian institutions . The rationale behind this study was that although RAPN is commonly used, there had been little evidence conclusively indicating that one approach was better than the other.
The researchers prospectively identified patients (n=3,468) diagnosed with a cT1-2 cN0 cM0 renal mass who underwent RAPN (n=2,405) or OPN (n=1,063). Clinical outcomes were collected in a central database. For the purposes of this analysis, the authors examined perioperative complications, renal function, and cancer control. Regression analysis and propensity-score matching were used to account for all measurable potential confounders with special attention to key determinants of clinical outcomes including tumor complexity and surgical experience.
Outcomes favoured patients undergoing RAPN compared with OPN for the rate of intraoperative complications (5.7% vs 9.3%; OR 0.39; 95% CI 0.22-0.68; P<0.001) and overall complications (18% vs 33%; OR 0.29; 95% CI 0.12-0.60; P<0.001). Patients receiving RAPN also lost significantly less blood and had significantly shorter hospital stays. With a median follow-up of 32 months, oncologic outcomes and longer-term survival outcomes were similar between groups, including positive surgical margins (4.3% vs 5.1%), local recurrence (1.6% vs 2.1%), systemic progression (1.8% vs 4.5%), and cancer-specific mortality (0.8% vs 2.4%). However, RAPN was associated with slightly longer ischemia times (16 vs 15 min) and lower postoperative kidney function when compared with OPN. Within 1 year, however, the renal function in both groups was similar, suggesting that this is a transient phenomenon.
After stratification according to complication severity or type, RAPN was associated with a lower rate of complications compared with OPN, including Clavien-Dindo ≥2 (12% vs 20%), Clavien-Dindo ≥3 (4% vs 6.1%), hemorrhagic (6.4% vs 9%), and urinary leakage-related (0.8% vs 4.6%) complications.
In conclusion, overall morbidity is lower after RAPN relative to OPN. Early renal function preservation is inferior after RAPN versus OPN, but no differences were observed at long-term follow-up. Oncologic outcomes are similar after either treatment modality.
1. Larcher A et al. The IRON study: Investigation of robot-assisted versus open nephron-sparing surgery. EAU20 Virtual Congress, 17-26 July 2020, Abstract 30.