Introduction

We compared the outcomes of transperitoneal and retroperitoneal robot-assisted partial nephrectomy (RAPN) within a large multi-institutional series of patients with kidney tumors.

Methods

We reviewed data from a prospectively mantained multi-institutional database on patients subjected to either transperitoneal or retroperitoneal RAPN between 2010 and 2016 at three tertiary care centers . Tumor complexity was preoperatively assessed according to the PADUA score. The Margin Ischemia and Complications (MIC) score was used to define optimal surgical outcomes (absence of Clavien-Dindo >2 complications, warm ischemia time [WIT] <20 minutes and absence of positive surgical margins). Finally, logistic regression model were fitted to test whether the surgical approach affected perioperative outcomes after adjustment for patient age, gender, body mass index (BMI), Charlson comorbidity index (CCI), tumor size and tumor complexity

Results

Overall, 343 (64.6%) and 188 (35.4%) were respectively subjected to transperitoneal and retroperitoneal RAPN. No significant differences were observed in terms of age, gender and BMI (all p>0.05), while a higher CCI was observed in the retroperitoneal group (p<0.001). Tumor size and tumor complexity did not differ significantly between the two groups (p>0.05). Operative time did not differ between the two groups (p=0.824), while estimated blood loss and length of stay were lower in patients subjected to retroperitoneal RAPN (p?0.013). Conversely, WIT was significanty lower in the transperitoneal group (mean WIT 15.2 vs. 17.1 mins; p=0.002). The proportion of patients with CD>2 complications was higher for the retroperitoneal approach (5.3 vs. 2.6%), but this difference did not achieve a statistical significance (p=0.051). Finally, no difference in the rate of positive surgical margins was observed (3.8 vs. 2.7%; p=0.491). The optimal surgical outcomes rate was 77.0% vs. 69.1% in the transperitoneal vs. retroperitoneal group, respectively (p=0.049). However, after adjustment for multiple confounders, no statistically significant difference between the two approaches was observed (OR: 1.14; 95%CI: 0.712-1.826; p=0.585). Conversely, both increasing PADUA score and male gender were associated with worse surgical outcomes (p<0.001).

Conclusions

In expert hands, both the transperitoneal and the retroperitoneal approach can be safely adopted to perform a RAPN, with the latter being associated with lower EBL and length of stay.

Funding

None