Unilateral Vasectomy Research Articles

Ultrasonography of spontaneous lesions of the genital system of three rams, and their influence on semen quality

Three young Suffolk ram lambs had lesions which rendered them reproductively unsound. One had a unilateral scrotal hernia, detected by palpation, and two had sperm granulomas which were detected by...

Testicular Effects of Vasectomy in Rats: An Ultrastructural and Immunohistochemical Study

Objectives. The correlation between infertility and morphofunctional alterations following vasal occlusion is not clearly understood. Although a correlation has been found between the expression of a high titer of antisperm antibodies and the status of infertility, the relationship between the immunoglobulin (Ig) depositions in the testis and ultrastructural alterations of the peritubular structures has not been clearly established. The objective of this study is to explain the etiopathogenesis of diffuse and focal testicular lesions caused by vasal obstruction. Methods. Unilateral vasectomy was performed on adult male rats. Ultrastructural changes of testicular tissues and immunostaining affinity of peritubular structures with anti-actin, anti-vimentin, anti-laminin, and anti-immunoglobulin G (anti-IgG) antibodies were analyzed. Results. In an ultrastructural study, vasectomized animals presented abundant collagen fibril accumulation in the peritubular area. In testis with intense IgG antibodies, staining revealed weak immunostaining of peritubular myoid cells with anti-actin antibodies, but intense immunostaining with anti-vimentin antibodies. The tubules of rats with no IgG deposition on peritubular structures revealed intense immunostaining with anti-actin antibodies but scant immunostaining with anti-vimentin antibodies. Anti-laminin deposits decreased severely in most of the tubules demonstrating intense IgG deposition. Conclusions. Our findings suggest that spermatogenesis deteriorates more severely in testes with dense IgG deposition. The sclerosis of the lamina propria in cases with vasal occlusion is secondary to alterations in the peritubular myoid cells. With the progressive changes that occur in the peritubular myoid cells or differentiation of the peritubular myoid cells that acquire active cell characteristics, collagen accumulation adjacent to these cells increases markedly. The alterations of the peritubular myoid cells reported here may be caused by alterations in basement membrane structures.

Analysis of the relationship between histologic alterations and the generation of reactive oxygen species in vasectomized rat testes

Objectives. To evaluate the effects of vasal obstruction on testicular structure, to determine if tissue and/or cell damage can cause significant reactive oxygen species (ROS) generation, and to correlate the histologic alterations to the measured levels of ROS products. Methods. To evaluate the effects of ROS generation in vasectomized testes, unilateral vasectomy was performed on 17 rats and tissue samples were examined by light microscopy. The histologic alterations were correlated to the measured tissue malondialdehyde levels by thiobarbituric acid analysis as an indicator of the ROS-induced tissue damage. Results. Unilateral vasectomy significantly affected the weights of the ipsilateral testes, but not the contralateral testes. No significant changes were noted in plasma estradiol, follicle-stimulating hormone, luteinizing hormone, and testosterone levels. The mean values of malondialdehyde were found to be significantly higher in vasectomized rats than in control rats (0.025 ± 0.008 versus 0.018 ± 0.007 nmol/mg protein) ( P <0.01). The malondialdehyde level was a mean of 28% lower in the contralateral testes tissue as compared to that found in ipsilateral testes ( P <0.01). Malondialdehyde output from vasectomized rats had a parallel correlation to tissue destruction. Conclusions. Our results indicate that overproduction of ROS may be involved in vasectomy-induced testicular damage.

Extragonadal sperm reserves, sperm-depletion rates, numbers of sperm per mating, and fertility with successive matings by intact or unilaterally vasectomized rats.

Because of the high rates of sperm production and large extragonadal sperm reserves of sexually rested male rats, mating trials are insensitive for detecting test-induced alterations in sperm production rates. Mating trials might be more sensitive if, independently of any experimental treatments under study, the number of sperm per mating was closer to the minimum requirements for normal fertility. The present study was undertaken to assess the impact of unilateral vasectomy and/or matings with up to three females in succession, for 1 hour each, on the number of sperm per mating and fertility, in comparison to corresponding values for males allowed unlimited matings with a receptive female overnight. Unilateral vasectomy did not affect sperm production, extragonadal sperm reserves, or removal of contralateral sperm during ejaculation (P > 0.05) but caused a 50% decrease in sperm numbers per mating. Sperm output, judged from numbers of residual extragonadal sperm in unmated and mated males, was excessive (290 x 10[6]) during conventional overnight mating with intact males and during the first and second hours of restricted mating (105 and 184 x 10(6) respectively, for intact males; one-half of these amounts for unilaterally vasectomized males). In contrast, sperm output during the third successive mating was minimal (nonmeasurable) but adequate, since pregnancy rates were similar for females mated first, second, or third in succession (P > 0.05). Since successive matings reduce the number of sperm per mating by natural methods, this approach may enhance the sensitivity of mating tests when applied for assessing the potential effects of experimental treatments on sperm production.

Comparison of Puncture Versus Vasotomy Techniques for Vasography in an Animal Model

Purpose We determined the adverse effects of 2 different techniques of vasography in an animal model. Materials and Methods Unilateral vasography was performed by a direct puncture technique with a lymphangiogram needle or through a partial thickness vasostomy technique in 2 groups of 10 adult Lewis rats using nonionic contrast medium mixed with methylene blue. Each rat had a contralateral vasectomy. A complete vasogram was confirmed by visualization of colored dye in the bladder. An additional group of 5 animals with unilateral vasectomy alone served as controls. The adverse effects of these 2 techniques were assessed by performing mating studies at 2 and 4 months after vasography. In vitro flow through the vas deferens, sperm granuloma formation and histology of the vas deferens at the vasography site were evaluated at sacrifice 5 months after vasography. Results The fertility of the 3 groups, as measured by the mean number of uterine implantation sites, was not significantly different at the 2 and 4-month breeding periods. In addition, we observed no significant decrease in the fertility of the 3 groups with time. Complete vasal obstruction was noted at sacrifice in 2 rats (20%) in the vasostomy group and none in the puncture or control group (p = 0.476). The mean in vitro flow rates through the vasa of the puncture and vasostomy vasography groups were significantly lower than those in controls (p <0.05) but not different from each other. The sperm granuloma formation rate was similar among the 3 groups. Conclusions Our results demonstrate that both vasography techniques have a measurable adverse effect on vasal flow rates and a potential adverse effect on fertility. The direct puncture method had a slightly lower complication rate than the partial thickness vasostomy method and it may be the preferable technique for the inexperienced microsurgeon.

Changes in the testes following vasectomy in the rat.

Six months and more after unilateral vasectomy in the rat, ipsilateral (same side) and bilateral testicular atrophy are common; this paper investigates their etiology. Ipsilateral atrophy is associated with the presence of a sperm granuloma in the head of the corresponding epididymis and appears to be pressure-mediated. That sperm granulomas at the epididymal head fail to relieve intraluminal pressure in the epididymal duct of the rat was supported by a study of the effects of ligation of that region. No histological evidence was found to indicate that bilateral atrophy was the result of an immune response. A radiological study does not support the idea that compression or displacement of testicular blood vessels by sperm granulomas is responsible for bilateral atrophy.

A clinical and ultrasonographic study of the testes and related structures of goats and rams after unilateral vasectomy

The semen quality, plasma testosterone concentrations and ultrasonographic changes were studied for up to 20 weeks after the unilateral vasectomy of two adult goats and two rams, and the gross and histological changes were examined post mortem. An intact ram and an intact goat served as controls. There was a marked decrease in the sperm concentration and the total numbers of sperm per ejaculate in both species. However, there seemed to be no effect on ejaculatory volume, mass motility and individual motile sperm, percentages of dead and abnormal sperm and plasma concentrations of testosterone. Ultrasonographically, the epididymal tail lost its characteristic heterogeneous texture and appeared enlarged. Anechoic masses, representing sperm granulomata, were visible within the epididymal tail of both the rams, and the epididymal head of one of the goats and at the cut end of the vas deferens in the other. They were observed as early as four to six weeks after surgery and their nature was confirmed post mortem. The sequential ultrasonographic changes in the testis and the epididymis are described.

The immunopathology of unilateral vasectomy in the ram

This study investigated the relationship between the local (spermatic granuloma) and systemic events after unilateral vasectomy in six rams. Spermatic microgranulomas were first observed at 4 weeks post vasectomy (PV), at which time lymphocytes, chiefly CD4 + (helper/inducer) cells, were incorporated into the periphery of the phagocytic wall. Although plasma cells accumulated around blood vessels near these early granulomas, they were not incorporated into them. All sectioned vas deferens contained additional microscopic spermatic granulomas away from the point of sectioning, as did one-third of cauda epididymides on the vasectomised side. There were significant ( P < 0.001) increases in T-lymphocytes, especially CD4 cells and plasma cells (chiefly IgG-containing) within the granulomas at each successive PV interval. Concurrent enzyme-linked immunosorbent assay indicated initial presence of IgG and IgM antisperm antibody in serum between 2 and 4 weeks PV. There were significant increases of IgG ( P < 0.01) and IgM ( P < 0.001) throughout the experiment but IgA antisperm antibody was negligible.

A clinical and ultrasonographic study of induced testicular and epididymal lesions in goats and a ram

Sequential ultrasonographic changes in the testis and the epididymis, semen quality and plasma testosterone concentrations were monitored after unilateral intra-testicular and intra-epididymal injections of chlorhexidine gluconate solution in three goats and a ram; the untreated, normal testis and epididymis were imaged as controls. Sixteen weeks after treatment unilateral vasectomy, ipsilateral to the normal testis and epididymis, was performed in two goats and a ram. Gross and histological changes postmortem were also recorded. Ejaculates collected after injection showed a decrease in mass and individual motility, sperm concentration and total sperm per ejaculate with an increase in the percentages of dead and abnormal spermatozoa. Those collected after vasectomy on the normal side had less than 20% motile sperm, most of which were dead (77–100%) and abnormal (62–100%). When observed ultrasonographically, within 24 h, the testis showed hypoechoic areas corresponding to the sites of injection. Later, the lesions decreased in echogenicity and showed acoustic shadowing, and were surrounded by a distinctly hyperechoic border. The epididymal tail showed an increased echogenicity, and had anechoic lesions with ill-defined borders within 24 h after injection. A hyperechoic border was subsequently observed around the lesions. Gross and histological examination of the testis revealed areas of long-standing tubular necrosis surrounded by mineralised tissue at the sites of injection. The epididymal tail showed fibrosis and sperm granuloma formation. Ultrasound imaging appears to be useful in diagnosing the presence of focal lesions of the testis or the epididymis.

The Effect of Unilateral Injury to the Vas Deferens on the Contralateral Testis in Immature and Adult Rats

The relationship between alterations in testicular histology and antisperm antibodies in immature and mature Lewis rats subjected to unilateral vasectomy was studied. Forty percent of immature rats and 90 percent of mature rats (p less than 0.01) demonstrated significant alterations in both the obstructed (vasectomy) testis and the contralateral testis. There were significant changes in antisperm antibodies (ELISA) in the animals which demonstrated histologic changes.

Bilateral effect of unilateral vasectomy on testicular testosterone biosynthesis

Tweive immature male dogs underwent a left vasectomy (group A). An additional five underwent a sham operation (group B). Sixteen weeks after the surgery, the bilateral mean values for caudal epididymal sperm content, the percentage of motile spermatozoa, intratesticular testosterone concentration, and testicular secretion of androgen-binding protein (in vitro) were significantly lower in group A. The mean peripheral serum testosterone responses 3 hours after human chorionic gonadotropin stimulation (3,000 IU) were significantly lower in group A than in group B (6.3 ng/mL v 9.5 ng/mL). These findings indicate a bilateral deficiency in both Leydig and Sertoli cell secretory function in unilaterally vasectomized dogs, resulting in impaired bilateral spermatogenesis and sperm maturation. The authors suggest that unilateral injuries of the vas deferens during hernia operations in children may result in bilateral testicular dysfunction.

Surgical Technique for Inguinal Surgery and its Effect on Fertility in the Wistar Rat Model

This study has explored the relatively neglected effects of operative manipulation of the vas deferens on fertility. Following unilateral vasectomy the contralateral vasa of 52 4-week-old Wistar rats were subjected to 7 different manipulations. After 7 weeks a fertility trial was conducted. All sham operated rats (n = 18) were fertile. Of the remaining 34 rats, 22 (65%) were sterile. All of those with tight ring reconstruction (n = 6) were sterile, due initially to venous obstruction. Nine of 14 rats with acute clip trauma (65%) remained fertile but 11 of 14 (78%) with full mobilisation were sterile owing to extensive avascular fibrosis of the vas deferens. These results suggest that overzealous cord handling and operative technique in the immature animal is counterproductive and leads to vasal occlusion. This may have important repercussions in paediatric inguinal surgery, with a subsequent higher incidence of azoospermia and male subfertility.

SUBSENSITIVITY TO ATP AND SOME ANALOGUES IN PREPARATIONS OF RAT CAUDA EPIDIDYMIS AND VAS DEFERENS AFTER VASECTOMY

1. The effects of ATP and some of its more stable analogues have been examined upon preparations of epididymal and prostatic halves of vasa deferentia and of cauda epididymides from rats that had undergone vasectomy by medial transection of the vas deferens. 2. After unilateral vasectomy, the potencies of ATP, beta, gamma-methylene ATP and 5'-adenylylimidodiphosphate (AppNHp) in tissues ipsilateral to the vasectomy were decreased compared to tissues from the contralateral unoperated side of the animal. 3. Tissues from bilaterally vasectomized rats were less responsive to ATP when compared to tissues taken from sham-operated rats. 4. Tissues taken from rats which had undergone vasovasostomies following unilateral vasectomy remained less responsive to these purines. 5. Responses of cauda epididymides and epididymal halves of vasa deferentia taken from unilaterally and bilaterally vasectomized rats to alpha, beta-methylene ATP usually did not differ from those of respective controls. 6. It is proposed that the subsensitivity which develops to ATP and some of its analogues on the epididymis and vas deferens following vasectomy may reflect increased breakdown, perhaps associated with changes in structural integrity of the tissues, rather than with the sympathetic denervation which is associated with vasectomy.

241 - Prevention of Antisperm Antibodies and Infertility After Unilateral Vasectomy by Pre-Operative Immunosuppression

241 - Prevention of Antisperm Antibodies and Infertility After Unilateral Vasectomy by Pre-Operative Immunosuppression

Occurrence of Sperm Antibodies in Adult Rats after Prefertile Traumatic vas Lesions

The occurrence of sperm antibodies has been studied in adult rats, which at prefertile age had been subjected to unilateral vasectomy, unilateral or bilateral crush injury of the vas or bilateral resection of the ductal artery. By means of indirect immunofluorescence technique, circulating sperm antibodies could be demonstrated in the blood in all groups 13 weeks postoperatively: unilateral vasectomy 15/17 (88%), unilateral crush injury 14/20 (70%), bilateral crush injury 13/20 (65%) and vascular injury 14/20 (70%). Sperm granulomas were observed in the unilateral vasectomy group (14/17) and in the bilateral crush injury group (4/20), whereas no sperm granulomas were seen in the unilateral crush injury or the vascular injury group.

Infertility in mice after unilateral vasectomy

The effects of unilateral vasectomy upon fertility and antisperm antibody production were studied using DBA/1J mice. Thirty-six males underwent either unilateral vasectomy, unilateral orchiectomy, or sham surgery. In vivo effects upon fertility were monitored by matings. Antisperm antibody titers were measured monthly. In vitro fertilization was performed in the presence of serum obtained 4 months postoperatively, and serum testosterone levels were also determined. After 3 months, only 1 male in the vasectomy group induced a pregnancy (1 of 12), while all but 1 of the males in the two control groups induced a pregnancy (20 of 21). The geometric mean antisperm antibody titer was 1:169 in the vasectomy group, while the orchiectomy and sham surgery groups had titers of 1:4 and 1:14, respectively (P less than 0.0001). The percentage of eggs fertilized in vitro in the presence of serum from experimental mice fell from 80% in the two control groups to 40% in the unilateral vasectomy group. Unilateral vasectomy induced infertility in DBA/1J mice and an antisperm antibody response. Sera containing these antibodies inhibited in vitro fertilization. This suggests that infertility after unilateral vasectomy may be immunologically mediated by antisperm antibodies.

Effects of hemicastration and unilateral vasectomy on the remaining gonad and on the FSH, LH and testosterone blood concentration in bulls

The effects of unilateral castration and vasectomy on the weight and microscopic appearance of the contralateral testis and on the blood levels of testosterone, LH and FSH, were studied in German Fleckvieh bulls. Testicular weights were higher in hemicastrated bulls (P < 0.01) and unilaterally vasectomized bulls (P < 0.05) when compared to controls, 377 ± 45g (x ± s, N = 4 and 281 ± 12g, N = 4 vs 226 ± 38g, N = 3, respectively. Testosterone concentrations were higher during the weeks 14 to 22 after surgery in both treated groups. LH levels were not different from controls, but FSH levels increased significantly (P < 0.01) two weeks after hemicastration and unilateral vasectomy. Different factors appear to regulate the LH and the FSH concentrations in bulls. The increase of FSH after hemicastration may indicate a reduced production of inhibin or an inhibin-like substance from the testes, and a similar increase after unilateral vasectomy suggests that this substance may be resorbed distal to the testes.

Pyrimidine Synthetic Enzymes of the Rat Testis and Epididymis Following Unilateral Vasectomy

The de novo pyrimidine synthetic enzyme, aspartate carbamyltransferase, and the two pyrimidine salvage enzymes, uridine and thymidine kinases, of the rat testis and epididymis were measured 1, 2, 4, 6, 8, and 10 wk following unilateral vasectomy. Vasectomy had no effect on organ wet weights and on testicular and epididymal asparate carbamyltransferase and thymidine kinase activities. Increases in the uridine kinase activity of the caput epididymidis at 2 wk and of the cauda epididymidis from the second to the sixth weeks were the only significant enzymatic changes observed.

Immunopathologic studies on vasectomized guinea pigs.

Vasectomies or sham vasectomies were performed on 208 guinea pigs to investigate whether vasectomy leads to immunologic complications in the first 4 postoperative months. Animals with vasectomies without obvious sperm leakage developed histopathologic changes in the testis and caudal epididymis. In some animals patchy hypospermatogenesis (7-13%) and intraductal accumulation of macrophages (5-6%) were apparent. Epididymal ducts dilated and luminal spermatozoa lost their antigens; some ducts ruptured and epididymitis and/or granulomas ensued. These early lesions are probably not due to immunologic mechanisms since: 1) they were not found in animals with leakage at vasectomy sites who exhibited positive antisperm antibody responses 2) they were found in animals with no detectable humoral immune response to sperm 3) they did not develop in the contralateral testes after unilateral vasectomy 4) immunofluorescence did not reveal in vivo binding of immunoglobulin IgC or complement component C3 in the lesions and 5) typical histologic lesions of experimental allergic orchitis were not found. In guinea pigs vasectomized 12-24 months earlier testicular lesions resembling allergic orchitis became apparent.(Authors modified)

Adaptations of the male reproductive tract and the fate of spermatozoa following vasectomy in the rabbit, rhesus monkey, hamster and rat.

The effects of vas obstruction in the rabbit rhesus monkey rat an d hamster were studied to determine the manner in which the vas deferens and epididymis dispose of spermatozoa after vasectomy. Distension of the vas and the distal portion of the epididymis was initially apparent but the subsequent response between species and individuals within species varied. In rabbits the distensibility of the distal portion of the tract appeared to insure its integrity for at least 24 weeks though granulomata appeared in the epididymis by 32 weeks. Some monkeys showed discrete granulomata in the vas deferens and/or cauda epididymis as early as 5-6 weeks after the operation. This was accompanied by a regression of a small though palpable enlargement of the cauda epididymis. Eruption of macroscopic granulomata occurred in the hamster epididymis within 8 weeks of the operation and about 30% of these animals showed a terminal cyst at the site of obstruction. Epididymal granulomata were not observed as frequently in rats as in the other species. The disposal of spermatozoa was found to depend on their ingestion by leucocytes which enter the tract through the granulomata and by epitheloid cells within the terminal vasal cysts. Ipsilateral di sruption of the seminiferous epithelium was consistently observed in association with granulomata and/or distension of the caput or corpus epididymis. The effect of unilateral vasectomy in rats and rabbits demonstrated that vasectomy had no general immunologically mediated suppressive effect on the potential fertility of these animals.