HISTOLOGIC CHANGES IN THE SEMINIFEROUS TUBULES AFTER VASECTOMY

Transcription

1 FERTILItY AND STI!RILITY Copyright 1974 The American Fertility Society Vol. 25, No.8, August 1974 PTillted in U.S.AI HISTOLOGIC CHANGES IN THE SEMINIFEROUS TUBULES AFTER VASECTOMY FLETCHER C. DERRICK, JR., M.D., W. LLOYD GLOVER, M.D., ZACHARY KANJUPARAMBAN, M.D., CECIL B. JACOBSON, M.D., MONICA McDOUGALL, B.S., KATHLEEN McCOWIN, M.S., H. DWIGHT MERCER, D.V.M., * AND LARRY D. ROLLINS, D.V.M. * Department of Urology and the Reproductive Genetics Unit of the Department of Obstetrics and Gynecology, the George Washington University Medical Center, Washington, D.C. The effects of vasectomy upon the testis and, more specifically, upon spermatogenesis have been investigated for many years. Sir Astley Cooper pioneered this research when, in 1827, he ligated the vas deferens of a dog. Six years later, he noted that the epididymis and proximal vas deferens were dilated with no gross testicular changes. In 1833, Curling2 performed bilateral vasectomies on three dogs, observed them for 14 months, and noted that they had distended epididymides "clogged with spermatozoa." In 1853, Gosselin 3 performed vasectomies on dogs and noted normal spermatogenesis for 6 and 10 months after vas ligation. In 1880, Brissand 4 reported the same phenomenon in rabbits and dogs; Griffiths reported similar results in and In 1924, Oslund/ after observing vasectomized dogs for 2~ months, found no degeneration in the germinal epithelium. His observations were similar in rats and guinea pigs. 8 In his review of the literature, Oslund 1 found that Hunter had studied a normally developed human testis in 1841 that contained spermatozoa despite a complete dysjunction of the vas deferens. Apparently, in 1904 Shatlock and Seligman 9 reviewed Cooper's work of Received July 3, *Veterinary Consultants from the Division of Veterinary Research, Bureau of Veterinary Medicine, Agriculture Research Center, Food and Drug Administration, Beltsville, Maryland / examined the same testicular specimen, and noted tubules that were normal in size and full of epithelial cells, with considerable numbers of spermatozoa. During the last decade, as vasectomy has become a widely accepted form of birth control, several reports have appeared concerning the effect of vasectomy ~n spermatogenesis. Various animal species have been studied for different periods of time, with different resultsy-14 The testes of smaller animals (eg, rats, hamsters, guinea pigs, and rabbits) tend to be migratory. Intra-abdominal migration may have an effect upon spermatogenesis, as pointed out by several of the early investigators. In 1968, Grewal and Sachan 15 performed vasectomies on dogs, and then biopsied the testes at 1, 3, and 6 months after vasectomy. He reported progressive degenerative changes at 1 month, but at 3 months he noted a mixture of degeneration. At 6 months he noted active regeneration in seven dogs. In 1972, JOShi 16 biopsied the testes of vasectomized dogs at 2-week intervals for 8 weeks. He observed progressive arrest of spermatogenesis starting at the second week. In an attempt to either confirm, augment, or disprove previously noted findings, we designed several experiments using medium-size healthy male dogs. A few humans were also studied. Although

2 650 DERRICK ET AL August 1974 FIG. 1. Testicular biopsy specimen of the dog at 1 week postvasectomy. Note the increased luminal sperm and accumulated spermiogenetic stages. (Reduced from X I60.)

3 Vol. 25, No.8 SEMINIFEROUS TUBULES 651 FIG. 2. Testicular biopsy specimen of the dog at 2 weeks postvasectomy. Note the increased spermatids with few sperm, indicative of retarded spermiogenesis. (Reduced from X 70.)

4 652 DERRICK ET AL August 1974 FIG. 3. Testicular biopsy specimen of the dog at 3 weeks postvasectomy. Note the definite spermatogenic arrest, with few stages beyond the primary spermatocyte. (Reduced from X 160.)

5 Vol. 25, No.8 SEMINIFEROUS TUBULES 653 FIG. 4. Testicular biopsy specimen of the dog at 6 weeks postvasectomy. Note the return of spermatogenesis with occasional spermatids. (Reduced from X70.)

6 654 DERRICK ET AL August 1974 FIG. 5. Testicular biopsy specimen of the dog at 10 weeks postvasectomy. Note the gradual meiotic progression of spermatogenesis with increasing spermatids. (Reduced from X 160.)

7 p Vol. 25, No.8 SEMINIFEROUS TUBULES 655 I FIG. 6. Testicular biopsy specimen (human) at 180 days postvasectomy. Note the progression of all spermatocyti(\."stages but reduced spermiogenesis. (Reduced from X 160.)

8 1 656 DERRICK ET AL August 1974 FIG. 7. Testicular biopsy specimen (human) at 10 years postvasectomy. Note the intraluminal spermatozoa showing completion of both spermatogenesis and spermiogenesis. (Reduced from X80.)

9 Vol. 25, No.8 SEMINIFEROUS TUBULES 657 ~ I not as many observations were recorded for the men, the findings were similar. MATERIALS AND METHODS Four different studies were designed initially; each used eight dogs that had had a routine bilateral vasectomy. The testes were then biopsied at 3-week intervals for 100 days. An additional three dogs were added to the study at a later date; after routine bilateral vasectomy, biopsies were performed at 2-week intervals for 100 days. After the initial 8- and 3-dog experiments, another experiment was designed using 10 dogs. All of these dogs had a bilateral vasectomy on the same day. At weekly intervals, one testis was biopsied. The tissue was examined both grossly and microscopically. Also a sample of tissue was submitted to rather extensive meiotic observations. The 13 human subjects were on the reversible vas deferens plug study. The reversible intravas device was placed in the vas lumen with a testis biopsy for control at that time. The patients had a repeat biopsy 4, 6, 12, or 18 months later. RESULTS The results of these experiments will be reported collectively since the findings were almost identical. The control animals showed normal spermatogenesis. Figure 1 shows a biopsy specimen taken 1 week after vasectomy. There was an accumulation of mature spermatozoa in the tubules, with no indication of spermatogenic arrest. Figure 2 shows a biopsy specimen taken after 2 weeks, with disappearance of mature spermatozoa but additional spermatids; there was, however, arrest in earlier spermatogenesis. Figure 3 shows a biopsy specimen 3 weeks postvasectomy, with definite spermatogenic arrest beginning. There were few secondary spermatocytes or spermatids. Figure 4 shows a biopsy specimen of testicular tissue at the end of 6 weeks. It demonstrates incomplete spermatogenic arrest with a few spermatids but no spermatozoa. Figure 5 shows a biopsy specimen representing testicular tissue between the 7th and 12th weeks, again showing diminution of spermatogenic progression. Figure 6 shows a human biopsy specimen taken 180 days after vasectomy, illustrating a moderate return of spermatogenesis with occasional mature spermatids. Biopsies at 300 days following vas ligation showed a limited return of spermatogenesis, but an occasional mature spermatozoon was found within the tubular lumen. Figure 7 shows a biopsy specimen taken from a man who had undergone vasectomy 10 years before. Progressive spermatogenesis was apparent, with mature spermatozoa within the tubules. However, the slight preponderance of meiotic precursors suggests diminished spermiogenesis. DISCUSSION Our work shows the depression and then gradual return of spermatogenesis after vasectomy. Our findings coincide closely with the recent work of PhadkeY He demonstrated a specialized macrophage that he called "a spermiophage," located in the epididymal lumen of vasectomized men. This spermiophage phagocytized the mature spermatozoa in the epididymal tubule. He observed dead as well as live spermatozoa being ingested. This reinforces our theory that spermatogenesis may be sensitive to pressure changes in the tubular system, as suggested by the observed progressive depression of spermatogenesis, with arrest at the primary spermatocytic stage. This arrest was found to be temporary after vasectomy. SUMMARY In the first 2 to 3 weeks after vasectomy, spermatogenesis remains relatively

10 658 DERRICK ET AL August 1974 unchanged. Actually, spermatozoa accumulate in the tubules. Between the third and sixth weeks, we uniformly observed progressive spermatogenic arrest, with few spermatozoa and decreased spermatids. By the 6th to 12th weeks, meiotic figures and spermatocytes reappeared, but no spermatozoa were observed in the tubules. Between 100 days and 300 days, return of spermatogenesis indicated by the finding of an occasional mature sperm within the tubules. Our meiotic studies showed this to be an arrest in early prophase. REFERENCES 1. Cooper Sir A: The Anatomy p.nd Surgical Treatment of Abdominal Hernia. Longman, London, Curling TB: A Practical Treatise on Diseases of Testis, Cord and Scrotum. London,l Gosselin L: Archen De Med. Paris 5. s. 11, Brissaud: Arch de Physiol. Second series, VII, 769, Griffiths: J Anat Physiol. 28:483, Griffiths: J Anat Physiol. 24: 209, Oslund RM: Vasectomy on dogs. Am J PhysioI70:111, Oslund R: A study of vasectomy on rats and guinea pigs. Am J Physiol 67:422, Shattock, Seligman: Proc R Soc Lond [BioI] 73:49, Cooper Sir A: Observations on the Structure and Diseases of the Testis. London, Segal RJ: Effect of vasoligation of 14 day old and 21 day old rats on spermatogenesis. Int J Fertil 17: 33, Sackler A: Gonad effects of vasectomy and vasoligation. Science 179:293, Kropp KA, Totonchy M, Bishop D, et al: Vasectomy on the guinea pig testis. Presented to the North Central Section of the American Urological Association, New Orleans, La., Thakur AN, Sheth AR, Rao SS: Biochemical studies on rat testes and sex accessory organs after vasoligation operation. Fertil SieriI23:834, Grewal RS, Sachan MD: Changes in testicle after vasectomy. Int Surg 49:460, Joshi KV, Ramedo IN, Sachder KN: Effects of vasectomy on testes. Int Surg 57: 711, Phadke AM: Fate of spermatozoa in cases of obstructive axospermia and after ligation of vas deferens in man. J Reprod Fertil 7: 1, 1964