Shum Cheuk Fan, Bahler Clinton D, Cary Clint, Masterson Timothy A, Boris Ronald S, Gardner Thomas A, Kaimakliotis Hristos Z, Foster Richard S, Bihrle Richard, Koch Michael O, Slaven James E, Sundaram Chandru P
1 Department of Urology, Indiana University School of Medicine , Indianapolis, Indiana.
2 Department of Biostatistics, Indiana University School of Medicine , Indianapolis, Indiana.
J Endourol. 2017 Jul;31(7):711-718. doi: 10.1089/end.2017.0184.
Partial nephrectomy (PN) reduces the risk of postoperative chronic renal insufficiency (CRI). However, some patients still develop CRI after PN, and may eventually require dialysis. Being able to predict renal function before PN helps in counseling patients and managing expectations. We aimed to construct nomograms that predict estimated glomerular filtration rates (eGFRs), defined by the modification of diet in renal disease (MDRD) and the chronic kidney disease epidemiology collaboration (CKD-EPI) formulae, at 1 year after PN, using only preoperative covariates as predictors.
We identified patients who underwent PN in our institution between 2004 and 2016, with known postoperative serum creatinine levels at 1 year. The preoperative covariates included patients' demographics, chronic comorbid conditions, tumor characteristics, and preoperative renal status. The endpoints were eGFRs at 1 year after PN, calculated using the MDRD and the CKD-EPI formulae. We first identified preoperative covariates with significant associations with the endpoints by Pearson correlation and independent samples t-test. Suitable covariates were then included in two multivariate linear regression models, for constructing and internally validating two nomograms.
461 patients were eligible for analysis. The percentage of patients with eGFR below 60 mL/min/1.73 m increased from 25% before PN to 35% at 1 year after PN. We included age, gender, African American race, body mass index, preoperative creatinine level, ipsilateral renal volume, solitary kidney status, tumor diameter, hypertension, diabetes, ischemic heart disease, and previous stroke in the multivariate linear regression models for nomogram construction. Internal validation showed bootstrap-corrected coefficients of determination of 0.61 and 0.70, for predicting eGFRs defined by the MDRD and CKD-EPI formulae, respectively.
We constructed and internally validated two nomograms to predict eGFRs at 1 year after PN, using only preoperative covariates as predictors.
部分肾切除术（PN）可降低术后慢性肾功能不全（CRI）的风险。然而，一些患者在接受PN后仍会发生CRI，并最终可能需要透析。能够在PN术前预测肾功能有助于为患者提供咨询并管理其预期。我们旨在构建列线图，仅使用术前协变量作为预测指标，来预测PN术后1年时根据肾病饮食改良（MDRD）公式和慢性肾脏病流行病学协作组（CKD-EPI）公式定义的估计肾小球滤过率（eGFR）。
我们确定了2004年至2016年间在本机构接受PN且已知术后1年血清肌酐水平的患者。术前协变量包括患者的人口统计学特征、慢性合并症、肿瘤特征和术前肾脏状况。终点指标是PN术后1年时使用MDRD和CKD-EPI公式计算的eGFR。我们首先通过Pearson相关性分析和独立样本t检验确定与终点指标有显著关联的术前协变量。然后将合适的协变量纳入两个多元线性回归模型，以构建和内部验证两个列线图。
461例患者符合分析条件。eGFR低于60 mL/min/1.73 m²的患者比例从PN术前的25%增加到PN术后1年时的35%。我们将年龄、性别、非裔美国人种族、体重指数、术前肌酐水平、患侧肾脏体积、孤立肾状态、肿瘤直径、高血压、糖尿病、缺血性心脏病和既往中风纳入列线图构建的多元线性回归模型。内部验证显示，对于预测由MDRD和CKD-EPI公式定义的eGFR，自展校正决定系数分别为0.61和0.70。
我们构建并内部验证了两个列线图，仅使用术前协变量作为预测指标来预测PN术后1年时的eGFR。
