Huang Wei-Hsuan, Chang Chao-Hsiang, Huang Chi-Ping, Wu Hsi-Chin, Hsieh I Po-Fan
Department of Urology, China Medical University Hospital, Taichung, Taiwan.
School of Medicine, China Medical University, Taichung, Taiwan.
Int Braz J Urol. 2017 Jan-Feb;43(1):80-86. doi: 10.1590/S1677-5538.IBJU.2015.0423.
The percentage of parenchyma preserved plays a predominant role in predicting renal function after partial nephrectomy (PN). Currently there is no standard method to estimate preserved renal parenchyma. In this study we propose a formula of the percentage of resected and ischemic volume (PRAIV) determined by a geometric model and evaluate the relationships between renal functional change and PRAIV as well as other clinical parameters.
We identified 71 patients who underwent open PN between January 2004 and April 2014. Assuming the kidney to be an ellipsoid with bilaterally equal volume and tumor to be a sphere, we calculated PRAIV by integral calculus. Nadir estimated glomerular filtration rate (eGFR) between postoperative 3 and 12 months were recorded. The correlation between percent eGFR reduction, PRAIV, and other clinical parameters were examined.
On univariate analysis, age (p=0.03), depth of tumor invasion (p=0.004), C index (p=0.003), RAIV (p=0.04), and PRAIV (p<0.001) were correlated with percent reduction of eGFR. However, only age (p=0.007) and PRAIV (p<0.001) were significantly correlated with percent reduction of eGFR on multivariate analysis. Depicting these values along the regression line, we found R2 was 0.194 and 0.073 for PRAIV and age, respectively.
PRAIV determined by a geometric model is a significant predictor of renal functional change after PN. Using PRAIV, we can estimate percent eGFR reduction preoperatively for better patient consultation and surgical planning.
保留的实质百分比在预测部分肾切除术（PN）后的肾功能方面起主要作用。目前尚无估计保留肾实质的标准方法。在本研究中，我们提出了一种通过几何模型确定的切除和缺血体积百分比（PRAIV）公式，并评估肾功能变化与PRAIV以及其他临床参数之间的关系。
我们纳入了2004年1月至2014年4月期间接受开放性PN的71例患者。假设肾脏为体积双侧相等的椭球体，肿瘤为球体，我们通过积分计算PRAIV。记录术后3至12个月的最低估计肾小球滤过率（eGFR）。检查eGFR降低百分比、PRAIV与其他临床参数之间的相关性。
单因素分析显示，年龄（p = 0.03）、肿瘤浸润深度（p = 0.004）、C指数（p = 0.003）、RAIV（p = 0.04）和PRAIV（p < 0.001）与eGFR降低百分比相关。然而，多因素分析显示，只有年龄（p = 0.007）和PRAIV（p < 0.001）与eGFR降低百分比显著相关。沿着回归线描绘这些值，我们发现PRAIV和年龄的R2分别为0.194和0.073。
通过几何模型确定的PRAIV是PN后肾功能变化的重要预测指标。使用PRAIV，我们可以在术前估计eGFR降低百分比，以更好地与患者沟通并进行手术规划。
