Ouwenga Michael K, Sharma Sameer K, Holley Paulette, Turk Thomas M T, Perry Kent T
Department of Urology, Loyola University Medical Center, Maywood, Illinois 60153, USA.
J Endourol. 2005 Sep;19(7):894-7. doi: 10.1089/end.2005.19.894.
We compared the load-release points of the Stone Cone and the new Cook Urological NTrap devices using an in vitro model of the ureter.
A strictured-ureter model was created using urethane tubing with a wire tie around it. A plastic bead was lodged above this narrowing. The Stone Cone, then the NTrap, was deployed in turn above this bead. The force required for each device to undeploy was measured over five trials.
Each device released the bead in every trial. The Stone Cone released at a mean of 0.190 lb, while the NTrap yielded at 0.861 lb.
Both of the devices released the plastic bead reliably and at low loads, although the NTrap did require statistically significantly more force than the Stone Cone. However, the loads for both devices were <1 lb, so the devices are unlikely to result in ureteral trauma. Whether a slight increase in load-release force or differences in design result in better stone-clearing ability of one device should be assessed in clinical trials.
我们使用输尿管体外模型比较了石锥（Stone Cone）和新型库克泌尿外科NTrap装置的负载释放点。
使用聚氨酯管并在其周围用金属丝扎紧创建一个输尿管狭窄模型。在该狭窄上方放置一个塑料珠。然后依次将石锥和NTrap部署在该珠子上方。在五次试验中测量每个装置展开所需的力。
每次试验中每个装置都释放了珠子。石锥平均在0.190磅时释放，而NTrap在0.861磅时释放。
两种装置均能可靠地在低负载下释放塑料珠，尽管NTrap所需的力在统计学上明显大于石锥。然而，两种装置的负载均<1磅，因此这些装置不太可能导致输尿管损伤。一种装置的负载释放力略有增加或设计差异是否会导致更好的结石清除能力，应在临床试验中进行评估。
