The impact of T1 renal tumor characteristics on baseline renal function in patients undergoing partial nephrectomy: A renal scan based objective assessment

Introduction and objectives: To objectively assess the impact of renal tumors characteristics and other measurable factors on baseline renal function in patient undergoing partial nephrectomy (PN). Methods: Patients who underwent laparoscopic PN for a T1 renal mass between 2012 and 2016 and who also had a mercapto-acetyltriglycine renal scan prior to surgery were retrieved from a single institution prospectively-collected database. Split renal function (SRF) and Effective Renal Plasma Flow (ERPF) for both the operated kidney and the unaffected contralateral were calculated. Patient demographics and tumor characteristics (e.g. size, location and; nephrometry score) were assessed. Renal function of both the operated and the unaffected; contralateral kidney were compared. Statistical analysis was performed by using Statistica 8.0 (StatSoft). Results: 227 patients were deemed eligible and included in the analysis. Univariable analysis showed a significant impact of age-adjusted CCI (p = 0.027), hypertension (p = 0.031) and age (p < 0.001) on operated kidney ERPF. Gender (p = 0.011), hypertension (p = 0.042), CCI (both standard and age-adjusted, p = 0.021 and = 0.003, respectively) and age (p < 0.001) were significantly; associated with contralateral unaffected kidney ERPF. Multivariable analysis confirmed age (p < 0.001) and hypertension (p < 0.021) as independent factors in both the operated and the unaffected kidney. Conclusions: Characteristics of the renal mass (including nephrometry score and size) seem to have no clinically relevant impact on baseline renal function in patients undergoing partial nephrectomy for cT1 renal tumors. Age, hypertension and co-morbidities confirm to represent un-modifiable significant factors influencing baseline renal function.