Presented by: Ryuichiro Sagehashi MD
Department of urology, Akita university school of medicine

Introduction

Robot-assisted partial nephrectomy (RAPN) allows for a safe dissection and precise tumor resection. Although RAPN also applies for even clinical T1b renal cell carcinoma (RCC), little is known about renal function after RAPN for cT1b renal tumor.

Materials

Fifty patients who underwent RAPN for cT1b renal tumor from November 2017 to September 2022 in Akita University Hospital were entered in this retrospective study. The estimated glomerular filtration rate (eGFR) was assessed at baseline and postoperative days (PODs) 180. A significant decline of renal function was defined as ≥ 15 % reduction from baseline eGFR. Uni- and multivariable logistic regression analyses (including age, sex, R.E.N.A.L nephrometory score, and perioperative factors such as operative time and estimated blood loss) were performed to elucidate the risk factors of renal function.

Results

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The median age was 62 years (IQR: 55-70). The median tumor diameter and R.E.N.A.L nephrectomy sore were 44 mm (IQR: 43-50) and 8 (IQR: 7-9), respectively. 82% of patients achieved Trifecta. The median eGFR at baseline and PODs180 were 70 mL/min/1.73m² (IQR: 60-78) and 61 mL/min/1.73m² (IQR: 53-71), respectively. The significant renal functional decline in at POD 180 was observed in 19 (38%) of 50 patients. By multivariable analysis, R.E.N.A.L nephrectomy score (HR 11.07; 95% CI [1.67-22.99]; p = 0.012) and estimated blood loss ≥ 200 ml (HR 6.279; 95% CI [1.35-19.02]; p = 0.019) were significant risk factors of renal functional decline. A subgroup-analysis of the component of R.E.N.A.L nephrectomy score showed that the L component (location relative to the polar lines) significantly impacted renal functional decline (HR 3.03; 95% CI [1.33-6.92]; P = 0.008).

Conclusion

RAPN was a safe and feasible approach for cT1b RCC. R.E.N.A.L nephrometory score, especially the L component, is a significant predictive factor of renal function decline after RAPN for cT1b renal tumors. 

Funding

Non.

Lead Authors

Kazuyuki Numakura, MD,PHD
Department of urology, Akita university school of medicine

Ryohei Yamamoto, MD,PHD
Department of urology, Akita university school of medicine

Mizuki Kobayashi, MD,PHD
Department of urology, Akita university school of medicine

Taketoshi Nara, MD,PHD
Department of urology, Akita university school of medicine

Mitsuru Saito, MD,PHD
Department of urology, Akita university school of medicine

Shintaro Narita, MD,PHD
Department of urology, Akita university school of medicine

Tomonori Habuchi, MD,PHD,Prof
Department of urology, Akita university school of medicine