Contact surface area predicts renal function in patients after partial nephrectomy
There exists an association between contact surface area (CSA) and the change in postoperative renal function after partial nephrectomy, a recent study has found. CSA can be used together with the nephrometry score to advise patients regarding the risk of renal functional decline after partial nephrectomy.
A total of 257 partial nephrectomy patients were included in the analysis. Median CSA was 14.5 cm2 (interquartile range [IQR], 6.2–36) and the median nephrometry score was 9 (IQR, 7–10).
In Spearman correlation analysis, CSA was associated with estimated blood loss (rs, 0.42; p<0.001), length of stay (rs, 0.18; p=0.005), and percent and absolute change in the estimated glomerular filtration rate (rs, –0.77 and –0.78; p<0.001).
Multivariable analysis revealed that CSA and nephrometry score independently predicted the absolute change in the estimated glomerular filtration rate (p<0.001). Furthermore, receiver operating characteristic curve analysis showed that CSA was better than the nephrometry score (AUC, 0.94 vs 0.80) in predicting >20-percent postoperative decline in the estimated glomerular filtration rate.
In this study, the investigators accessed a prospectively maintained kidney cancer database for patients treated with partial nephrectomy between 2014 and 2016. Data sourced from preoperative cross-sectional imaging were used to calculate CSA. The association between CSA and perioperative variables was then assessed.
In addition, the investigators examined the correlation between postoperative renal functional outcomes, CSA and the RENAL (radius, exophytic/endophytic properties, nearness of tumour to collecting system or sinus, anterior/posterior, location relative to polar lines, and tumour touches main renal artery or vein) nephrometry score.