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Biomedical subjects

E E Brueschke

Publications and source records attributed to E E Brueschke.

10 recordsLinked to original sources
PubMed1979

Development of a reversible vas deferens occlusive device. VI. Long-term evaluation of flexible prosthetic devices.

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.

Animals↗
PubMed1977

Transcervical tubal occlusion with a steerable hysteroscope: implantation of devices into extirpated human uteri.

A new steerable fiberoptic hysteroscope particularly useful in visualizing the tubal ostia has been evaluated in 61 extirpated uteri. The efficacy and safety of this hysteroscope were shown. The feasibility of deploying occlusive devices into the intramural portion of the tubes with the steerable hysteroscope was demonstrated. Whether these devices or modifications thereof will prove to be superior to other currently tested methods of occlusion, e.g., caustics, plastics, or cautery under in vivo conditions, remains to be established. The steerability of the hysteroscope has advantage irrespective of the method to achieve transcervical tubal occlusion as it allows coaxial alignment of the delivery.

Adult↗
PubMed1977

Hysteroscopy.

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Endoscopy↗
PubMed1976

Anatomical sizes of the human vas deferens after vasectomy.

After vasectomy, the lumen of the testicular side of the vas deferens dilates, apparently because of internal pressure from accumulation of spermatic fluid. This dilatation occurs within the 1st postoperative year. It causes a thinning of the wall of the vas without significant increase in the external diameter. The extent of dilatation is similar in the same man, but differs markedly between individuals, the mean increase in diameter being approximately 70%. The implications of this difference in size are discussed with regard to vas anastomosis and to the possible use of devices to rejoin the vas or to bridge a defect created by a prior vasectomy.

Dilatation, Pathologic↗
PubMed1976

New studies with intravasal devices. The soft valve.

In contrast to the results that were obtained with rigid ended prosthetic devices, effective sperm transport occurred for prolonged periods of time through the IITRI Vas-Valve, which had soft silicone rubber flexible end tubes when implanted in the vasa deferentia of dogs. Such transport could be halted by device occlusion with stainless steel springs or with shuttle stem valves. Opening the devices resulted once more in the passage of spermatozoa as well as the production of offspring, indicating that these devices have the potential for being useful as a human male contraceptive method. More research needs to be performed to determine why there is an over-all decrease in sperm output after device implantation and to evaluate and adverse side effects of such devices. The presence of Dacron velour-covered suture rings on the devices permitted effective tissue ingrowth and prevented leakage or recanalization in all cases.

Animals↗
PubMed1976

A prosthetic vas deferens.

Six dogs were implanted with the synthetic vas deferens device as part of our continuing research into the development of a reversible occlusive device for implant in the transected vas deferens. The experimental objectives were to assess the effects of sperm path length and duration of aspermia on total sperm count and motility by implanting three different lengths of the device in animals with different degrees of aspermic duration induced by bilateral vasectomy. Device lengths varied from 1.55 cm to 4.3 cm including the pilot tubes. The prosthesis is fabricated entirely of silicone rubber with Dacron velour tissue ingrowth material bonded to the outside surface of the ring to which vas ends are sutured. The pilot tubes extend 4 mm beyond the suture rings and are 0.6 mm OD with a 0.3 mm ID that extends through the entire length of the device. The flexible pilot tubes are an important feature of this design and insert into the vas lumen ensuring alignment between the device and the vas deferens while maintaining the necessary resiliency to adapt to the inherent movements of the vas without perforation. All animals included in these experiments were carefully selected and conditioned before implant. The evaluation of performance was based on semen samples collected at one week intervals. Sperm subsequently appeared in the ejaculate of all 6 dogs, demonstrating that the restoration of sperm transport can be restored after bilateral vasectomy through the implantation of a prosthetic vas deferens. The potential application of this device to the human male for the restoration of fertility appears excellent.

Animals↗
PubMed1976

The human uterotubal junction: a scanning electron microscope study during different phases of the menstrual cycle.

Uterotubal junctions from surgically extirpated human uteri were examined. The specimens were obtained during different phases of the menstrual cycle. The interstitial portions of the tubes together with the cornual areas were dissected, excised, and their luminal surfaces exposed. The specimens were then processed for scanning electron microscopy. The surface epithelium of both the cornual endometrium and interstitial endosalpins. Ciliated cells were more numerous in the endosalpinx. Cyclic changes in ciliated cells were minimal, while cyclic secretory activity was demonstrated, especially in the endometrium. The transitional area between the endometrium and the endosalpinx was characterized by a marked increase in the number of ciliated cells, and a tendency of the secretory cells to assume a flattened, polygonal shape. These morphologic features suggest a possible role in the transport and/or maintenance of spermatozoa and/or ova.

Adult↗
PubMed1975

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.

Animals↗
PubMed1975

Development of 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.

Animals↗