Redhill, United Kingdom.
J Urol. 2010 Apr;183(4):1417-21. doi: 10.1016/j.juro.2009.12.023. Epub 2010 Feb 20.
We present the first randomized clinical study using BackStop, a novel reverse thermosensitive water-soluble polymer that is dispensed above the stone(s) and temporarily occludes the ureter to prevent retropulsion of stone fragments during ureteroscopic lithotripsy. After fragmentation is completed and concretions are extracted, conventional irrigation with saline dissolves the polymer, which is then flushed out.
A total of 68 subjects with a single stone in the proximal ureter and an indication for ureteroscopic lithotripsy were enrolled in this prospective, randomized, single-blind, controlled, multisite clinical study. Each subject was randomly assigned to the BackStop group (34) or the control group (34 with no antiretropulsion device). For subjects in the experimental group BackStop was dispensed into the ureter above the stone using a 3Fr or 5Fr catheter. Ureteroscopic lithotripsy was performed in all subjects using pneumatic or laser energy. Measured end points included the retropulsion rate, the need for subsequent procedures, the stone-free rate at followup, the occurrence of adverse events and ureteral occlusion, if any, and post-stone fragmentation and extraction.
Subjects randomized to the BackStop group experienced a statistically significant (p = 0.0002) lower rate of retropulsion (8.8%, 3 of 34) vs the control group (52.9%, 18/34). There were no adverse events in the BackStop group and BackStop was successfully dissolved in every subject, resulting in a patent ureter.
BackStop appears to be a novel, safe and effective means of preventing stone fragment retropulsion during ureteroscopic lithotripsy for the management of ureteral stones.
我们介绍了首例使用 BackStop 的随机临床试验，这是一种新型的反向热敏水溶性聚合物，施用于结石上方，暂时阻塞输尿管，以防止输尿管镜碎石术中结石碎片的逆行。碎石完成并提取结石后，用生理盐水常规冲洗溶解聚合物，然后冲洗掉。
共有 68 名近端输尿管有单个结石且需要进行输尿管镜碎石术的患者参加了这项前瞻性、随机、单盲、对照、多中心的临床研究。每位患者随机分为 BackStop 组（34 例）或对照组（无反推装置的 34 例）。对于实验组的患者，将 BackStop 通过 3Fr 或 5Fr 导管施用于结石上方的输尿管。所有患者均使用气动或激光能量进行输尿管镜碎石术。测量的终点包括逆行率、后续治疗的需要、随访时的无石率、不良事件和输尿管阻塞的发生情况（如果有），以及碎石和结石提取后的情况。
随机分配到 BackStop 组的患者逆行率明显较低（8.8%，3/34），与对照组（52.9%，18/34）相比，差异具有统计学意义（p = 0.0002）。BackStop 组无不良事件，且在每个患者中均成功溶解，使输尿管保持通畅。
BackStop 似乎是一种安全有效的防止输尿管镜碎石术治疗输尿管结石时结石碎片逆行的方法。
