Total renal volume and renal function after radical nephrectomy in renal neoplasm

Introduction: The reduction of renal mass after radical nephrectomy (RN) for renal neoplasm, could be associated with compensatory hypertrophy of the contralateral kidney. The capacity of compensation will determine the renal function (RF) evolution. Measuring of total renal volume (TRV) of the remaining kidney pre and post RN can help assess the RF evolution.

Objectives: To determine the correlation between TRV pre and post nephrectomy (a year of follow-up) with RF.

Materials and methods: A retrospective cohort study was carried out in 47 patients who had undergone RN from 2014 to 2018, due to renal cell carcinoma (confirmed by histopathology). The TRV was calculated, pre and post (a year of follow-up) RN, using ellipsoid formula equation, which were compared with clinical and analytical data. The results were analyzed by multivariate linear logistic models.

Results: The median age at the time of RN was 70 years old (range, 40-88 years). Most of them were men, 66%. The estimated glomerular filtration rate (eGFR) pre and post nephrectomy was 78 (40-100) and 53.3ml/min/m² (30-90) respectively (p=0.01). The TRV pre and post-nephrectomy was 168.2ml (100.4-257.2) and 187.8ml (115.5-273.1) respectively (p=0.001). The pre-nephrectomy eGFR (β=0.62; p=0.034) and the TRV (β=1.08; p<0.0001) were positively correlated with the post-nephrectomy TRV, while the eGFR at year of follow-up was correlated negatively (β=-1.18; p=0.047).

Conclusions: The measurement of pre and post nephrectomy TRV can help to predict renal function evolution at a year of follow-up.