Autoimmune hypospermatogenesis in vasectomized guinea pigs

Long-term reproductive consequences of no-scalpel vasectomy in beagles

The effects of vasectomy on the reproductive organs in various species are controversial. This study investigated the morphological change and apoptosis of the testis, epididymis, and vas deferens in beagle dogs 12 months after vasectomy. The male beagles were divided into two groups: vasectomized and sham-operated groups (n=5 in each). Histopathological, ultrastructural, and TUNEL evaluation of the changes in the testis, epididymis, and ductus deferens of each animal were conducted 12 months after surgery. The mean lumen diameter, cellular thickness, mean interstitial distance, and lumen area fraction of each seminiferous tubule and ductus epididymis were measured by stereological analysis. The results showed that, compared with the sham-operated group, the seminiferous tubular epithelial cells of the testes in the vasectomized group were disorderly arranged and scattered. Significant atrophy and apoptosis were found in the endothelial cells, and a range of ultrastructural variations were observed in the cells of testes, epididymis, and vas deferens in vasectomized group. It was concluded that complete obstruction of the vas deferens as a traditional contraception method is not absolutely safe in terms of the reversal of fertility in the long run. Techniques of relieving the inner pressure in the vas deferens while maintaining the efficacy of male contraception need to be explored.

Clinical, ultrasonographic and pathological features following unilateral vasectomy in rams

The effects of vasectomy on testes and related structures of animal species and men are largely disputable. These possible effects were studied in the ram, an established experimental animal model used to investigate genitalia pathophysiology. In each of five rams, vasectomy in the left spermatic cord was carried out; subsequently, the clinical and ultrasonographic features were monitored up to 12 months post-operatively. The rams were sequentially euthanatized 1, 3, 6, 9 and 12 months post-operatively; gross- and histo-pathological examination of their testes and related structures were carried out. Four of the five rams developed sperm granulomas at the proximal to the testis end of vas deferens or/and at the tail of the epididymis; these were palpable from the first and the third month after vasectomy, respectively. Ultrasonographic findings on the vasectomy side were increased size and echogenicity of the epididymal tail, as well as anechoic areas, representing sperm granulomas, visible in the epididymal tail 1 week after vasectomy and in the proximal to the testis end of vas deferens 4 weeks after vasectomy. Gross pathological findings were limited on the vasectomy side and included adhesions between the parietal and the visceral vaginal tunic, enlarged and firm epididymal tail and presence of sperm granulomas at the epididymal tail or/and at the proximal to the testis end of vas deferens; the granulomas contained creamy material. Histopathological changes were observed mainly in the epididymal tails, consisting of a central mass of spermatozoa, surrounded by a layer of macrophages, surrounded in turn by loose vascular connective tissue rich in lymphocytes and plasma cells. With the exception of signs of mild hypospermatogenesis observed in one ram euthanatized 9 months after surgery, and of a slight increase in seminiferous tubule diameter and in seminiferous epithelium height in the rams euthanatized 6 and 9 months after surgery, which are both findings of no clinical importance, no clinical, ultrasonographic, gross- or other histo-pathological changes were observed in the testicular parenchyma during a 12-month post-operative period. These results demonstrate that vasectomy has little if any detrimental effect on the morphologic characteristics of the spermatogenesis in rams.

Effects of vasectomy on spermatogenesis and fertility outcome after testicular sperm extraction combined with ICSI

BACKGROUND

Each year 40,000 men have a vasectomy in the UK whilst another 2400 request a reversal to begin a second family. Sperm can now be obtained by testicular biopsy and subsequently used in assisted conception with ICSI. The study aims were to compare sperm yields of men post-vasectomy or with obstructive azoospermia (OA) of unknown aetiology with yields of fertile men and to assess any alteration in the clinical pregnancy rates after ICSI.

METHODS

Testicular tissue was obtained by Trucut needle from men who had undergone a vasectomy >5 years previously or had OA from other causes and from fertile men during vasectomy. Seminiferous tubules were milked to measure sperm yields. Numbers of Sertoli cells and spermatids and thickness of the seminiferous tubule walls were assessed using quantitative computerized analysis.

RESULTS AND CONCLUSIONS

Sperm yields/g testis were significantly decreased in men post-vasectomy and in men with OA, relative to fertile men. Significant reductions were also observed in early (40%) and mature (29%) spermatid numbers and an increase of 31% was seen in the seminiferous tubule wall (basal membrane and collagen thickness) of vasectomized men compared with fertile men. Clinical pregnancy rates in couples who had had a vasectomy were also significantly reduced.

Clinical significance of unilateral testicular obstruction in subfertile males

Unilateral testicular obstruction has been defined by exploratory scrototomy in 80 spontaneously infertile males. The most common sites of obstruction were either in the tail of the epididymis after previous infection (40 cases) or in the vas deferens due to congenital absence or after previous infection or surgery (24 cases). Half of the patients had severe oligozoospermia (less than 5 million/ml) and three-quarters had developed antisperm antibodies, often in high titres. Spermatogenesis was shown by testicular biopsy to be normal (Johnsen score-count greater than 8.0) in almost all of the obstructed testes, and serum FSH levels were normal. Following surgical reconstruction, with prednisolone therapy if indicated by high antisperm antibody titres, 19 (32%) of 60 patients with adequate follow-up successfully impregnated their female partners, with the best results occurring in 30 men who started with sperm counts less than 5 million/ml, 12 of whom (40%) were successful. Removal of irreparably blocked testes in 10 men led to profound falls in high antisperm antibody titres, with production of two pregnancies. Unilateral testicular obstruction appears to be a correctable cause of infertility in some human males.

Antisperm antibodies and circulating immune complexes of vasectomized men with and without coronary events

We compared antisperm antibody and circulating immune complex (CIC) levels in serum samples from 101 vasectomized and 101 normal age-matched nonvasectomized men; 31 of each group had histories of coronary heart disease (CHD). Vasectomy and CHD status were treated as categorical independent variables in the two-way analysis of variance. Elevations of both systolic and diastolic blood pressures were significantly associated with age and body mass index but not vasectomy. Antisperm antibodies (immobilizing and agglutinating) were significantly associated with vasectomy (P less than or equal to .001); the incidences were similar in men with and without CHD. The CICs were significantly associated with vasectomy in a Staphylococcus aureus (FcSa) CIC assay (P less than or equal to .001) and a Raji cell CIC assay (P less than or equal to .05). A third CIC assay, the Clq binding assay, did not reveal a difference between any subgroups. Generally, CICs occurred more frequently in the CHD group by the FcSa assay and particularly the Raji cell assay (P less than or equal to .001). In summary, vasectomized men had a higher incidence and higher levels of circulating antisperm autoantibodies and CICs than did age-matched controls.

Quantitative pathologic changes in the human testis after vasectomy. A controlled study

To determine whether there are any deleterious changes in the human testis after vasectomy, we obtained testicular biopsy specimens from 31 healthy men undergoing vasectomy reversal and from 21 healthy, fertile volunteers. Morphometric analyses of these specimens revealed a 100 per cent increase in the thickness of the seminiferous tubular walls (P less than 0.001), a 50 per cent increase in the mean cross-sectional tubular area (P less than 0.001), and a significant reduction in the mean number of Sertoli cells (P less than 0.01) and spermatids (P less than 0.01) per tubular cross section in the post-vasectomy group, as compared with the control group. Focal interstitial fibrosis was observed in 23 per cent of the specimens from the post-vasectomy group and in none from the control group. There was a significant correlation (P less than 0.01) between interstitial fibrosis and infertility in patients who underwent a surgically successful vasectomy reversal (sperm in the ejaculate). None of the other measured characteristics correlated with infertility after vasectomy reversal. We conclude that significant morphologic changes occur in the human testis after vasectomy. The presence of focal interstitial fibrosis was associated with a high incidence of infertility in this series.

Prevention of monkey sperm penetration of zona-free hamster ova by sperm antibody obtained from vasectomized cynomolgus monkeys

Incubation of antisperm sera from vasectomized cynomolgus monkeys (Macaca fascicularis) with monkey sperm caused a fourfold reduction of sperm attachment to and penetration of zona-free Golden hamster ova. The attachment of sperm to hamster ova was reduced from 64% to 11%, and the penetration of ova was reduced from 20% to 5%. Sperm antibodies block sperm attachment to the vitelline membrane, thus preventing ovum penetration. This blockage may be one of the reasons for low fertility rates observed following reanastomosis of the vas deferens in those vasectomized males that show high levels of circulating antisperm antibody.

Spermatogenesis in the vasectomized monkey: quantitative analysis

The seminiferous epithelium in mature vasectomized Macaca fascicularis was examined quantitatively to assess spermatogenesis. Monkeys were bilaterally vasectomized and controls were bilaterally sham operated. At postoperative periods of 10 and 18 months, groups of monkeys were castrated and their testes prepared for morphologic analysis. Diameters were measured in 100 cross sections of seminiferous tubules from each animal. Numbers of spermatogonia (Ad and Ap), preleptotene spermatocytes, pachytene spermatocytes, and step 7 spermatids, relative 10 Sertoli cell nucleoli, were counted in stage VII tubules. Tubule diameter and germ cell numbers per Sertoli cell nucleoli were not altered by vasectomy. Our study demonstrates quantitatively that spermatogenesis in the monkey is not inhibited up to 18 months following vasectomy.

Immunological consequences of vasectomy

In more than 50% of men, vasectomy leads to auto-immune pathology. The auto-immune response to sperms following vasectomy is triggered by the phagocytosis of sperm in the epididymis. In the humoral immune response, sperm agglutinating, sperm immobilizing, and antibodies to sperm nuclear protamines occur, as early as 3-4 days after vasectomy. The incidence reaches 60-70% within 1 year and remains almost the same even after 20 years. Presence and effects of circulating immune complexes following vasectomy are discussed with reference to reported increased incidence of atherosclerosis and auto-immune orchitis in experimental animals. There is no positive conclusion whether vasectomy leads to cell mediated immunity to spermatozoa.

Prevention of autoimmunization to spermatozoa by passive antibody

The objective of this investigation was to determine if sperm antibody formation after vasectomy in guinea pigs can be inhibited by passive administration of antiserum to spermatozoa. Sperm antibody was obtained by bleeding vasectomized guinea pigs which had sperm-agglutinating antibody titers of 1 : 16 or higher. Gamma globulin was obtained by ammonium sulfate precipitation. Vasectomized guinea pigs were injected with immune gamma globulin and normal gamma globulin for a period of two weeks after vasectomy. In the group receiving normal gamma globulin the serum titer of sperm-agglutinating antibody reached 1 : 32 and remained at that level for duration of the study. In guinea pigs receiving immune gamma globulin detectable serum titers of sperm-agglutinating antibody did not develop. The investigation suggests that sperm antibody formation can be prevented by treating vasectomized animals with passive sperm antibody to spermatozoa.

Consequences of vasectomy: an immunological and histological study related to subsequent fertility

Studies of 2 groups of patients 2 years and 8 years following vasectomy failed to demonstrate evidence of cell mediated immunity to sperm. Histological examination of testicular tissue from 11 patients undergoing reversal of vasectomy showed significant abnormalities in each. However, subsequent fertility within 15 months occurred in 7 (63.6%) of these patients. The nature of the testicular changes and the possible aetiological factors are discussed.

Effect of Freund's complete adjuvant on the immune response of vasectomized rats

Rats were vasectomized, vasectomized and injected in the epididymis with Freund's complete adjuvant (FCA), or only injected with FCA without vasectomy. All were positive for sperm agglutinins, in contrast to sham-operated or untreated controls. Generally, the highest titers were found in vasectomized or unoperated animals given FCA, indicating that local granuloma formation promotes the production of sperm autoantibody, even in nonvasectomized rats.

A second look at Steinach's second procedure: testiculoepididymal occlusion in man and dog

After advocating vas occlusion as a biological method for rejuvenating aging males, Steinach had suggested that the effect might be more pronounced if the obstruction were placed proximal to the epididymis. This Steinach II procedure has now been studied in 15 dogs and five men. Occlusion was performed at the level of the vasa efferentia, avoiding any vascular trauma. Radiological visualization confirmed a perfect block. There were no untoward reactions, such as orchitis or hydrocele. In dogs, widespread degeneration in the seminiferous tubules was evident, and the total Leydig cell volume showed an increase from 0.7 to 1.0 ml/testis. The changes, however, were not significantly different from conventional vasectomy. In men, there were considerable preexisting senile changes, and the total Leydig cell volume was already as high as 2.8 ml/testis. These changes obscured any possible effect of Steinach II operation.

Vasovasostomy and vas occlusion: preliminary observations using artificial devices in guinea pigs

Intravas devices designed to reverse a vasectomy or to occlude the vasa instead of transecting them were evaluated in guinea pigs. Absorbable intravas devices (AID) were inserted into the vasa at the time of vasovasostomy and produced a return of normal semen quality in 73% of the experimental animals as compared with only 40% in the control group. Seventy per cent of the AID group sired litters. In a second group of guinea pigs, vasectomy was replaced by the bilateral insertion of reversible intravas plugs (RIP) which occluded the lumina. After a period of azoospermia, the central, occlusive pins were removed from the devices. Sperm-positive animals were bred and three of five sired normal offspring. Histologic examination of the vasa revealed morphologic changes in some AID animals, these being attributed to the vasectomy procedure. A similar evaluation of the functional RIP insertion site revealed the desired occlusive tissue-device interfaces.

Allergic orchitis lesions are adoptively transferred from vasoligated guinea pigs to syngeneic recipients

Histopathology typical of allergic orchitis developed in testes of inbred guinea pigs 16 months after vasoligation. A similar histopathology was found in unoperated testes after unilateral vasoligation. Peritoneal exudate cells from vasoligated guinea pigs transferred identical lesions to syngeneic recipients. The testicular lesions in long-term vasoligated guinea pigs have an immunological basis.

Changes in the structure and function of the testes and epididymides in vasectomized rams

Vasectomized rams were studied with regard to the structure and function of their testes and epididymides at different periods up to 3 years and 9 months after the operation, and compared with intact control rams. Control rams showed a marked seasonal pattern with higher values for size and weight of testes, diameter of seminiferous tubules, Sertoli cell ratios for germ cells, and size of cauda epididymidis immediately prior to and during the breeding season than at other times of the year. In vasectomized animals the seasonal pattern was ill-defined, the testicular parameters were lower, and the cauda epididymidis was larger than in intact rams. Spermatogenesis was qualitatively and quantitatively affected after vasectomy, with a sequential ebb-and-flow pattern of spermatogenic arrest and hypospermatogenesis. Epididymal changes included the development of multiple spermatoceles surrounded by a granulomatous reaction, and disturbances in the process of sperm maturation.

Vasectomy in rhesus monkeys. III. Light microscopic studies of testicular morphology

Rhesus monkeys were randomly assigned to undergo various surgical procedures. The animals were followed from one to sixty-six weeks postvasectomy, at which time they were sacrificed and their tissues prepared for light and electron microscopy. Vasectomy in the rhesus monkey, as in certain other species, appears to be a procedure not attended with widespread testicular atrophy or histologic evidence of impaired spermatogenic potential utilizing the procedures and postoperative periods studied. Why certain animals exhibited focal degenerative changes is unclear; perhaps a certain population, yet to be defined, is more sensitive to such procedures, resulting in testicular alterations. It is important that such a population and such changes be defined to predict more accurately the possibility of successful vasovasostomy and reestablishment of fertility.

Autoantibodies following vasectomy

The incidence of 7 different autoantibodies was determined in 904 men 3 months to 6 years after vasectomy operations and in 700 control subjects. There was no clinically significant increase in autoantibodies in the vasectomized group nor was any autoimmune disease detected that could be related to the vasectomies.

Immunological and morphological effects of vasectomy in the rabbit

Half of the rabbits developed antisperm antibodies (measured by either indirect immunofluorescence or sperm immobilization tests) after either a unilateral or bilateral vasectomy. The raised antibody levels, particularly six months or longer after vasectomy, often accompanied patchy orchitis. Seminiferous tubules from such animals exhibited sloughed, multinucleated, and immature germinal cells which were engulfed by phagocytic cells. Mononuclear infiltrates were occasionally present. The basal lamina infolded and thickened by means of supernumerary layers and appeared to be endocytosed by cells of the seminiferous tubules. Four months after vasectomy, numerous phagocytic cells were seen in migrate through the intact epithelium of zone 1 in the caput epididymidis, and were particularly prevalent in animals that exhibited testicular damage. These macrophages may serve to present sperm antigens to lymphocytes.

Changes in testis of guinea pig after vasectomy

Thirty adult guinea pigs were bilaterally vasectomized and subsequently sacrificed at one, three, and six months after operation. Cell counts were performed on five seminiferous tubules from each animal to identify and quantitate changes in spermatogenesis. Forty-three per cent of the animals had alterations in spermatogenesis that were characterized by generalized hypospermatogenesis and presence of multinucleated spermatids. There was a high incidence (93 per cent) of sperm-agglutinating antibodies in the vasectomized group. Sperm antibodies were not detected in the normal and sham-operated animals. Mean testicular weights and seminiferous tubule diameters were significantly reduced in the hypospermatogenic animals. The intersitial tissue of the vasectomized and sham-operated animals was morphologically indistinguishable from that of unoperated animals.