Patient and tumor characteristics.

Background
Preservation of renal function is an important goal in renal cell carcinoma-related surgery. Although several case-dependent techniques for renal pedicle clamping and hemostasis have been used, their effects on long-term renal function are controversial.
Methods
The clinical records of 114 patients who underwent off-clamp non-renorrhaphy open partial nephrectomy at our hospital were retrospectively reviewed. Perioperative estimated glomerular filtration rate (eGFR) preservation was calculated, and predictors of eGFR decline 12 months post-surgery and overtime deterioration of renal function were identified using a multivariate regression analysis.
Results
The median patient age was 65 years, and the median tumor size was 27 mm. The mean eGFR preservation at 1, 3, and 12 months post-surgery were 90.1%, 89.0%, and 86.9%, respectively. eGFR decline at 1 and 3 months were associated with poor eGFR preservation at 12 months with the odds ratio (95% confidence interval (CI)) of 1.97 and 3.157, respectively. Multivariate regression analyses revealed that tumor size was an independent predictor of eGFR decline at 12 months. Among 65 patients with eGFR preservation over 90% at 1 month post-surgery, eGFR value of 28 patients deteriorated below 90% at 12 months post-surgery compared with preoperative eGFR. Tumor size and eGFR preservation at 1 month were independent predictors of long-term renal function deterioration.
Conclusion
Tumor size predicted eGFR decline 12 months post-surgery. Only a mild decline in eGFR was observed between 3 and 12 months after open partial nephrectomy. Tumor size and eGFR preservation at 1 month predicted the deterioration of renal function over time.

背景
肾功能保护是肾细胞癌相关手术的核心目标之一。尽管目前已采用多种基于患者个体情况的肾蒂阻断与止血技术，但此类技术对患者长期肾功能的影响仍存在广泛争议。
方法
本研究回顾性分析本院114例接受无肾蒂阻断、不伴肾修补的开放性部分肾切除术患者的临床资料。计算围手术期估算肾小球滤过率（estimated glomerular filtration rate, eGFR）的保留率，并通过多因素回归分析明确术后12个月eGFR下降及肾功能随时间恶化的预测因素。
结果
患者中位年龄为65岁，中位肿瘤直径为27mm。术后1、3及12个月的平均eGFR保留率分别为90.1%、89.0%及86.9%。术后1个月及3个月的eGFR下降与术后12个月的eGFR保留不佳显著相关，其比值比（odds ratio, OR）分别为1.97和3.157，对应95%置信区间（confidence interval, CI）。多因素回归分析显示，肿瘤大小是术后12个月eGFR下降的独立预测因素。在术后1个月eGFR保留率超过90%的65例患者中，有28例患者的eGFR较术前水平降至90%以下，且该变化发生于术后12个月时。肿瘤大小及术后1个月的eGFR保留率是肾功能随时间恶化的独立预测因素。
结论
肿瘤大小可有效预测术后12个月的eGFR下降情况。开放性部分肾切除术后3~12个月期间，仅观察到eGFR出现轻度下降。肿瘤大小及术后1个月的eGFR保留率可预测肾功能随时间的恶化进程。