Objective: To investigate factors influencing renal functional compensation(RFC) of the preserved kidney after radical nephrectomy (RN).
Methods: A total of 286 patients treated with RN in Peking University People's Hospital were retrospectively analyzed. Preoperative body mass index (BMI), systolic blood pressure (SBP), history of smoking, history of chronic diseases and other basic information, as well as preoperative blood biochemistry, urine routine, imaging examination results were recorded. All the patients underwent 99mtechnetium-diethylenetriamine pentaacetic acid (99mTc-DTPA) renal scans before operation. The surgical method, pathology and blood creatinine values from 1 month to 60 months after RN were recorded. Preoperative and postoperative estimated glomerular filtration rate (eGFR) was calculated by the chronic kidney disease epidemiology collaboration (CKD-EPI) formula. Renal functional compensation was defined as percent change in eGFR of the preserved kidney after RN compared with the preoperative eGFR. Univariate and multivariate regression analyses were used to identify predictive factors of RFC.
Results: Median age was 61 years and 65.4% of the patients were male. Early stage (T1 or T2) tumors were found in 83.6% of the cases. 18.5% of the patients had preoperative diabetes mellitus, 39.5% had hypertension, 19.2% had a history of smoking, and 27.6% were found to have renal cyst on the contralateral side. In the study, 226 cases underwent laparoscopic radical nephrectomy and 60 cases underwent open radical nephrectomy. Renal clear cell carcinoma was the most common pathological type, accounting for 88.5%. The median tumor maximum diameter was 4.5 cm (0.7-13.5 cm). Median renal function compensation was 27% one month after radical nephrectomy. Functional stability was then observed to 5 years. The results of univariate analysis showed that age, gender, preoperative blood uric acid, preoperative urine protein, contralateral renal cyst, and percentage of split renal function of contralateral kidney were correlated with RFC (P < 0.05). Among them, UA level and split renal function of contralateral kidney were strongly negatively correlated with RFC. The results of multivariate linear regression analysis showed age (P < 0.001), blood uric acid (P < 0.001), urine protein (P=0.002), preoperative eGFR (P < 0.001) and the split renal function of contralateral kidney (P < 0.001) were independent predictors of RFC.
Conclusion: The basic examinations, such as blood biochemistry, urine routine and renal scan before RN are of great significance in predicting the compen-satory ability of the preserved kidney after RN, which is supposed to be taken into consideration when making clinical decision.
目的: 探讨单侧肾细胞癌根治性肾切除术(radical nephrectomy，RN)后留存肾肾功能代偿(renal functional compensation，RFC)的影响因素。
方法: 回顾性分析286例在北京大学人民医院接受RN的肾细胞癌患者的临床资料，记录术前体重指数(body mass index，BMI)、收缩压、吸烟史、慢性疾病史等基础信息和术前血生化、尿常规、影像学等辅助检查结果。所有患者均在术前行99m锝-二乙三胺五乙酸(99mtechnetium-diethylenetriamine pentaacetic acid，99mTc-DTPA)肾动态显像检查。记录手术方式、术后病理结果和术后1~60个月的血肌酐数值。术前、术后估计肾小球滤过率(estimate the glomerular filtration rate，eGFR)由慢性肾脏疾病流行病学合作组(chronic kidney disease epidemiology collaboration，CKD-EPI)公式计算，RFC百分比定义为RN术后留存肾eGFR较术前eGFR变化的百分比。采用单因素和多因素线性回归分析确定影响留存肾RFC的独立预测因素。
结果: 患者中位年龄61岁，65.4%为男性，83.6%的病例为早期肾细胞癌(T1期和T2期)。18.5%的患者术前合并糖尿病，39.5%合并高血压，19.2%既往有吸烟史，27.6%在术前影像学检查中发现健侧肾囊肿。226例患者行腹腔镜RN，60例行开腹RN。肾透明细胞癌是最主要的病理类型，占88.5%，中位肿瘤最大径为4.5 cm(0.7~13.5 cm)。术后1个月时中位RFC百分比为27%，在随后5年内保持稳定。单因素变量分析结果显示年龄、性别、术前血尿酸水平、术前是否存在蛋白尿、是否存在健侧肾囊肿以及术前健侧肾的分肾功能百分比与RN术后留存肾RFC百分比具有相关性(P＜0.05)，其中，术前血尿酸水平和术前健侧肾分肾功能百分比与术后RFC百分比呈极强负相关性。多因素线性回归分析结果显示，年龄(P < 0.001)、术前血尿酸水平(P < 0.001)、术前是否存在蛋白尿(P=0.002)、术前eGFR(P < 0.001)和术前健侧肾分肾功能百分比(P < 0.001)是术后RFC的独立预测因素。
结论: 术前血生化、尿常规和肾动态显像等基本辅助检查对于预测RN术后留存肾的代偿能力意义很大，临床决策时需综合考虑多方面因素对术后基线eGFR的影响。
Keywords: 99mTc-DTPA renal dynamic imaging; Radical nephrectomy; Renal cell carcinoma; Renal functional compensation.