EAU 2018: The Impact of Surgical Strategy in Robot-Assisted Partial Nephrectomy: Should we Treat Anterior Tumors with Transperitoneal Access and Posterior Tumors with Retroperitoneal Access?

Copenhagen, Denmark (UroToday.com) Available comparisons between trans- [tRAPN] and retroperitoneal robot-assisted partial nephrectomy [rRAPN] are scarce and affected by relevant selection bias. The aim of this study was to compare perioperative morbidity, renal function and positive surgical margins [PSM] after tRAPN and rRAPN focusing on the position of the tumour.

A total of 1184 patients diagnosed with a cT1-2 cN0 cM0 renal mass elected for tRAPN or rRAPN were assessed. Primary outcomes were Clavien-Dindo ≥2 complications [CD≥2], ischemia time [IT, min], postoperative and 12-month estimated glomerular filtration rate [eGFR, mL/min] and PSM. Secondary outcomes were estimated blood loss [EBL, mL], operative time [OR, min] and length of stay [LOS, days]. After 1:1 nearest-neighbour propensity-score matching to account for all measurable potential confounders, logistic and linear regression analyses tested the effect of tRAPN vs. rRAPN on the study outcomes. Sub-analyses testing the hypothesis of better outcomes in case of tRAPN for anterior tumour and rRAPN for posterior tumour were performed with interaction test.

After propensity-score matching, 384 tRAPN and 384 rRAPN patients remained. No difference with respect to age, gender, comorbidities, preoperative eGFR, single kidney status, tumour size, RENAL score, hilar position, face and side involved and year of surgery was recorded between tRAPN and rRAPN patients. CD≥2 complication rate was 5.7% after tRAPN and 8.6% after rRAPN (p=0.1). Median IT was 19 min after tRAPN and 20 min after rRAPN (p=0.3). Median postoperative eGFR was 82 after tRAPN and 78 after rRAPN (p=0.04). Median eGFR was 88 after tRAPN and 87 after rRAPN (p=0.6). PSM rate was 3.6% after tRAPN and 1.8% rRAPN (p=0.2). Median EBL was 100 ml after tRAPN and 50 ml after rRAPN (p<0.0001). Median OR time was 120 min after tRAPN and 124 min after rRAPN (p=0.1). Median hospital stay was 7 days after tRAPN and 8 days after rRAPN (p=0.3). At interaction test, no advantage in case of tRAPN for anterior tumour or rRAPN for posterior tumour was recorded.

In conclusion, no relevant difference with respect to morbidity, renal function and PSM was recorded between tRAPN and rRAPN. Moreover, neither tRAPN for an anterior tumour, nor rRAPN for posterior tumour yields better results. The two strategies are equally effective regardless of tumour position.

Presented by: Larcher A, MD, ORSI Academy, Dept. of Urology, Melle, Belgium

Written by: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre, twitter: @GoldbergHanan at the 2018 European Association of Urology Meeting EAU18, 16-20 March, 2018 Copenhagen, Denmark