尽管输尿管支架置入术是输尿管狭窄的常见保守治疗方法，但长期留置输尿管支架是否能保护肾脏免受实质萎缩和功能恶化尚不清楚。在这项研究中，我们评估了留置输尿管支架一年或更长时间患者的肾实质厚度（RPT）变化并估计了肾小球滤过率（eGFR）。作为对照，我们还评估了与留置经皮肾造口术 (PNS) 一年或更长时间相关的 RPT 变化。使用聚合物输尿管支架，每三个月更换一次。 RPT 使用计算机断层扫描 (CT) 进行测量。总共纳入了 55 名具有基线和随访 CT 扫描的患者的 69 个肾单位。中位随访期为 29 个月。输尿管梗阻的病因分别为恶性和良性病变，分别为 27 例和 28 例。大多数情况下RPT明显降低。 1 年时，单侧病例 RPT 中位降低率为 17.3%，显着高于健康对侧肾脏。 eGFR 与包括对侧肾脏在内的总 RPT 之间存在很强的相关性。输尿管支架肾脏（包括双侧病例）RPT 降低率也显着高于 35 例 PNS 患者的 39 个肾单位。这项研究的结果表明，留置输尿管支架在保护肾功能方面的长期疗效有限。定期成像对于评估残余肾功能可能至关重要。

Although ureteral stenting is a common conservative treatment for ureteral stricture, it is unclear whether a long-term indwelling ureteral stent protects the kidney against parenchymal atrophy and functional deterioration. In this study, we evaluated the changes in renal parenchymal thickness (RPT) and estimated the glomerular filtration rates (eGFR) in patients with indwelling ureteral stents for one year or more. As a control, we also evaluated changes in RPT associated with indwelling percutaneous nephrostomy (PNS) for one year or more. Polymer ureteral stents were used and replaced every three months. RPT was measured using computed tomography (CT). Totally, 69 renal units in 55 patients with baseline and follow up CT scans available were enrolled. The median follow-up period was 29 months. The etiologies of ureteral obstruction were malignant and benign disease in 27 and 28, respectively. RPT was reduced obviously in most cases. At 1 year, the median reduction rate of RPT was 17.3% in unilateral cases, which was significantly higher than that in the healthy contralateral kidney. There was a strong correlation between eGFR and total RPT including the contralateral kidney. The reduction rate of RPT in kidneys with ureteral stents including bilateral cases was also significantly higher than that in 39 renal units of 35 patients with PNS. The results of this study suggest that the long-term efficacy of indwelling ureteral stents in preserving renal function is limited. Regular imaging may be essential to evaluate the residual renal function.