Brueschke E E, Zaneveld L J, Kaleckas R A, Wingfield J R
Fertil Steril. 1979 May;31(5):575-86. doi: 10.1016/s0015-0282(16)44005-7.
Fifty-three dogs received implants of several types of flexible devices containing valving mechanisms. These devices were constructed entirely of silicone rubber with the exception of the valve stem, which was made of stainless steel. Generally, the devices were (1) implanted in the open mode and left this way for 27 to 44 months, (2) implanted in the closed mode and kept this way for 11 to 12 months before the valves were reopened, (3) implanted in either the closed or open mode and cycled to the opposite mode every 3 months (four or five cycles), or (4) implanted in either the closed or open mode and cycled to the opposite mode every 6 months (two or three cycles). Different implant methods were also evaluated. Semen analyses were regularly performed on all of the dogs, and a number of the animals were bred during the experiments. It can be concluded that (1) the devices can be opened and closed successfully over long periods, respectively allowing and preventing sperm transport; (2) the breeding ability of the animals is not impaired while the devices are in the open mode, independent of the type of device; (3) the devices do not result in an enhanced incidence of congenital abnormalities in the offspring; and (4) the success rate of device performance does not depend on the method of implanatation used. Thus, the results clearly indicate that the basic mechanism of a soft, reversible valve is a feasible approach to conception control.
53只狗接受了几种带有瓣膜机制的柔性装置植入。这些装置除了阀杆由不锈钢制成外，其余完全由硅橡胶构建。一般来说，这些装置（1）以开放模式植入并保持这种状态27至44个月；（2）以闭合模式植入，并在瓣膜重新打开前保持这种状态11至12个月；（3）以闭合或开放模式植入，每3个月循环至相反模式（四或五个周期）；或者（4）以闭合或开放模式植入，每6个月循环至相反模式（两或三个周期）。还评估了不同的植入方法。定期对所有狗进行精液分析，并且在实验期间让一些动物进行繁殖。可以得出以下结论：（1）这些装置能够分别在长时间内成功打开和闭合，从而允许和阻止精子运输；（2）当装置处于开放模式时，动物的繁殖能力不受损害，与装置类型无关；（3）这些装置不会导致后代先天性异常发生率增加；（4）装置性能的成功率不取决于所使用的植入方法。因此，结果清楚地表明，柔软、可逆瓣膜的基本机制是一种可行的避孕方法。
