Abstract: PD73-05
Sources of Funding: None

Introduction

A retroperitoneal approach compared to transperitoneal during partial nephrectomy (PN) can provide superior access to posteriorly located renal tumors. To elucidate any benefit to this approach, we compared perioperative and renal functional outcome in the largest comparison to date of transperitoneal and retroperitoneal robotic PN (TP-RPN and RP-RPN) for posterior tumors.

Methods

The present study identified 1684 patients who underwent RPN for a solitary clinical T1 renal tumor from 6 different surgeons from 2006 to 2016. Patients with a tumor anterior (n=519) or neither anterior nor posterior to the coronal plane (i.e., lateral, n=253) were excluded from the analysis. There were 519 patients who underwent either TP-RPN (n=357, 68.8%) or RP-RPN ( n=162, 31.2%) for a posteriorly located tumor that met inclusion for this analysis. TP-RPN and RP-RPN patients were 1 to 1 propensity score matched on pre-operative and tumor-specific characteristics. Perioperative outcome and renal function outcome at 22 months (IQR 8.9-41.6 months; Range 3.2-95.9 months) were compared with Mann-Whitney U tests and Chi-squared tests of independence.

Results

Between the propensity score matched TP-RPN (n=157, 50%) and RP-RPN (n=157, 50%) patients, no significant differences in age (p=.481), age adjusted CCI (p=.053), body mass index (p=.996), baseline eGFR (p=.502), tumor size (p=.741) or R.E.N.A.L. Nephrometry score (p=.308) were identified. Operative time (185.0 vs. 157.0, p<.001) was longer in TP-RPN vs. RP-RPN patients. No significant differences in warm ischemia time (p=.618), estimated blood loss (p=.178), positive surgical margins (p=.501), medical post-operative complications (7.0% vs. 2.5%, p=.064), major complication rates (p=.295), or progression of Chronic Kidney Disease stage at 22 months (p=.550) were identified.

Conclusions

RP-RPN for posterior tumors resulted in reduced operative time when compared to TP-RPN. All other measures including ischemia time, blood loss, margin rates, complications, and renal function did not differ between the two approaches, both of which are safe to treat posterior tumors.

Funding

None