Marvin Burns

Development of a Reversible Vas Deferens Occlusive Device. II Effect of Bilateral and Unilateral Vasectomy on Semen Characteristics in the Dog

16 male beagles were used to study the effect of bilateral and unilateral vasectomy on the semen characteristics in the dog during research into the development of a reversible vas deferens occlusive device. Bilateral vasectomy of 8 dogs resulted in the immediate absence of spermatozoa from the ejaculate of 7 dogs indicating that the spermatozoa are stored in the epididymis and not partially in the ampullary region of the vas as in the human. No significant decrease in volume after bilateral vasectomy could be detected in the group as a whole but some individual dogs showed distinct changes. Unilateral vasectomy of 8 dogs resulted in an overall 50% decrease in total sperm count; again some individual variations were observed. These variations probably depended on the functional activity of the remaining testicle. After unilateral vasectomy volume decreases were noted with the amount of decrease proportional to the individual decrease in sperm count. There was no change in the percent of viable spermatozoa after unilateral vasectomy and there was no increase in abnormal sperm forms. Neither bilateral nor unilateral vasectomy appeared to affect the pH of the ejaculate. Details of the manual and artifical vagina collection methods and the vasectomy technique in the dog are described.(AUTHORS MODIFIED)

Development of a Reversible Vas Deferens Occlusive Device: V. Flexible Prosthetic Devices *

In contrast to the results with rigid-ended prosthetic devices implanted in the vas deferens of the dog, effective sperm transport was obtained for prolonged periods of time with flexible-ended (all soft) devices. Such transport could be halted by device occlusion with clips or shuttle stem valves. Opening the devices resulted once again in the passage of spermatozoa, indicating that these devices may be potentially useful as reversible male contraceptives. More research is necessary to determine the cause of an overall decrease in sperm output after device implantations and to evaluate any adverse side effects of such devices. Dacron velour-covered suture rings on the devices permitted effective tissue ingrowth and prevented leakage or recanalization.

Development of a steerable hysteroscope: Studies in the baboon

A steerable fiberoptic hysteroscope was developed with an integrated fluid circulatory system and a channel that can be used either for operative procedures or for the passage of a uterotubal occlusive device delivery assembly. The hysteroscope was demonstrated to be a safe and practical instrument for intrauterine observations, using the baboon as the animal model. Postpartum baboons were used for a majority of the experiments since the cervix of most cycling animals could not be sufficiently dilated to permit hysteroscope insertion. Estrogen-progesterone treatment resulted in softening of the cervix enough to allow hysteroscopic examination in 66 per cent of the animals so treated. Hysteroscopy was performed on 18 baboons. In almost all cases the uterotubal junctions were visualized and appeared as small slits or depressions. Measurements of the mean uterine length, fundal width, normal cervical diameter, and the diameter to which the cervix can maximally be dilated are reported for cycling, hormone-treated, and postpartum baboons.