Department of Urology, Kidney Stone Center, Tokyo Metropolitan Ohtsuka Hospital, Toshima-ku, Tokyo, Japan.
Int J Urol. 2022 Jun;29(6):542-546. doi: 10.1111/iju.14835. Epub 2022 Feb 25.
Difficult ureter can be a challenge for accessing upper urinary tract during lithotripsy. In this study, we evaluated the risk factors for the incidence of difficult ureter in retrograde ureteroscopic lithotripsy. Moreover, we aimed to develop a predictive model for the incidence of difficult ureter.
We retrospectively reviewed consecutive retrograde ureteroscopic lithotripsies performed at our institution between 2009 and 2021. A total of 1010 renal units were evaluated: 449 units with renal stones only and 561 units with ureteral stones, with or without renal stones.
The overall incidence of difficult ureter was 5.9%, with a higher incidence in the renal alone stone group than in the ureteral stone group (7.8% vs 4.5%, P = 0.026). Multivariate regression analysis revealed three risk factors for the incidence of difficult ureter: absence of stone history (odds ratio 5.67, 95% confidence interval 2.40-13.4, and P < 0.001), age ≤45 years (odds ratio 3.61, 95% confidence interval 2.05-6.37, and P < 0.001), and renal stone only (odds ratio 2.11, 95% confidence interval 1.22-3.64, and P = 0.008). A simple model using these three risks enabled the stratification of the incidence rate of difficult ureter, with the incidence of high-risk cases being 12.7%.
The greatest risk factor for the incidence of difficult ureter was the absence of stone history, followed by age 45 years or younger, and having only renal stones. In high-risk cases of difficult ureter, the possibility of secondary lithotripsy should be explained to the patients.
在进行碎石术时，输尿管困难可能是进入上尿路的挑战。在这项研究中，我们评估了逆行输尿管镜碎石术时发生输尿管困难的危险因素。此外，我们旨在建立输尿管困难发生的预测模型。
我们回顾性分析了 2009 年至 2021 年期间在我院进行的连续逆行输尿管镜碎石术。共评估了 1010 个肾单位：449 个肾单位仅有肾结石，561 个肾单位有输尿管结石，伴或不伴肾结石。
输尿管困难的总发生率为 5.9%，单纯肾结石组的发生率高于输尿管结石组（7.8%比 4.5%，P=0.026）。多变量回归分析显示，发生输尿管困难的三个危险因素是：无结石史（比值比 5.67，95%置信区间 2.40-13.4，P<0.001）、年龄≤45 岁（比值比 3.61，95%置信区间 2.05-6.37，P<0.001）和单纯肾结石（比值比 2.11，95%置信区间 1.22-3.64，P=0.008）。使用这三个风险因素的简单模型可以对输尿管困难发生率进行分层，高危病例的发生率为 12.7%。
发生输尿管困难的最大危险因素是无结石史，其次是年龄 45 岁或以下，以及仅存在肾结石。在输尿管困难的高危病例中，应向患者解释进行二次碎石术的可能性。
