Robotic-assisted partial nephrectomy: lower morbidity

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).

presented the large, non-randomised, comparative, prospective study of clinical outcomes after RAPN or OPN at 9 high-volume European, North American, and Asian institutions [1]. 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). Detailed preoperative data concerning the tumours was not documented in this study. 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 tumour 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; see Table). 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 ischaemia times (16 vs 15 minutes) and lower post-operative kidney function when compared with OPN. However, the renal function in both groups was similar within 1 year, suggesting that this is a transient phenomenon.

Table: Clinical outcomes of patients treated with OPN versus RAPN [1]



OPN, open partial nephrectomy; RAPN, robot-assisted partial nephrectomy; eGFR, estimated glomerular filtration rate

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 (4.0% vs 6.1%), haemorrhagic (6.4% vs 9.0%), 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. The trend towards worse progression rates following OPN raises the question of whether there was an underlying negative selection in this cohort due to worse pre-operative tumour characteristics; baseline tumour data were not collected in this study.

1. 
   
   1. Larcher A, et al. EAU20 Virtual Congress, 17-26 July 2020, Abstract 30.

Posted on 20 August 202029 February 2024