REVERSIBILITY OF STERILIZATION PRODUCED BY VAS-OCCLUSION CLIP*

P.S. JHAVER**, JOSEPH E. DAVIS, HYUNG LEE, J.F.HULKA***, GEORGE LEIGHT
Journal of Fertility & Sterility Vol.22 No.4 April 1971

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Carolina Population Centre, University of North Carolina, Chapel Hill, North Carolina U.S.A.

Programs to curb the population growth have historically concentrated on the female, and extensive studies of methods of contraception in the male have not been undertaken. The most effective male method is sterilization by vasectomy with techniques varying from ligation of the vas to excision of a portion of the vas and ligature of the cut ends. Jhaver, Schmidt, and Tilak1-3 have reported these methods. A method using a tantalum clips**** on the vas deferens was reported by Armstrong4. This study evaluates the use of tantalum clip placed around the vas with the hypothesis that this procedure would lend itself to more successful reversibility.

The idea of reversibility is central to the consideration of improving male sterilization techniques. The vasectomy procedure now in use is recommended as irreversible although successful reanastomosis (sperm in the ejaculate) has been accomplished in 50-80% of the patients 5-10. Documentation of a restoration of fertility, however, is usually reported at a lower rate. A procedure that is reversible in a higher percentage of cases would undoubtedly make the operation more acceptable to a large number of men. The increased use of such a procedure would allow it to become a useful part in family planning programs. Specifically, it was hypothesized that placing of a clip on the vas would render the ejaculate aspermic and that removal of the clip would allow fertile sperm to appear in the ejaculate. This report is concerned with the evaluation of these hypotheses.

METHOD

Thirteen dogs of random genetic background were obtained in good health and free of disease. Under general anesthesia and with sterile technique, the vasa were exposed and occluded with one or two clips in operations during July and August 1968, by Dr. Jhaver. Postoperatively, the dogs were kept in 3 X 3 foot metal cages for a period of 3 weeks, and then were transferred to separate kennels with adequate shelter and running facilities. They were maintained in good health on Purina Dog Chow and water throughout their subsequent periods of observation. Sperm samples were obtained by ejaculation after exposing the dogs to a bitch maintained in constant estrus with estrogen injections. These ejaculates were examined immediately under the microscope for the presence of motile sperm.

Subsequent operations included the removal of clips by Dr. Jhaver from three dogs after total aspermia had been noted 5 weeks after the vas occlusion procedure. These three dogs and the remaining seven dogs underwent further operations 1 year after initial placement of clips. Drs. Davis and Lee performed Reanatomosis using a microsurgical technique on seven dogs; the remaining three simply had clips removed. The sixth ejaculate after subsequent surgery was evaluated for motile sperm11. Three dogs were eliminated during the period of observation: one was sacrificed due to an unrelated disease (manage), one failed to produce ejaculate due to prostatitis after surgery, and one particularly appealing dog was given away early as a household pet.

Figure 1 shows the tantalum clip, Fig 2 shows the application of this clip onto the vas, and Fig 3 shows the instrument for removal of the clip.

RESULTS

Table 1 presents summary of the sperm analyses, obtained at 4-week intervals after surgery throughout the period of observation. This table also shows the presence or absence of adhesions and scar tissue distorting the operative site at the time subsequent surgery, the number of end to end anatomosis attempted 1 year after placement of the clip, and the presence of sperm in the sixth ejaculate after surgery and in the vasa at the time of sacrifice 6 weeks after the second series of operations.

The following observations can be made.

Single Clips: In the four dogs in which one clip was applied, aspermia was not achieved. One dog, which had one clip on the left vas and two clips on, the right (1055) was initially negative, but became positive under observation on the subsequent year. At sacrifice, it was apparent by sperm in the vasa that the vas, which had two clips, had been the occluded one.

Double Clips: In all six dogs in which a double clip was applied, the dogs were rendered aspermic. This aspermia persisted in three dogs observed for a period of 1 year.

Reversibility: Of the dogs rendered aspermic with double clips, attempts by Dr. Jhaver at removal of the clips alone to restore sperm in three of these (728, 726 and 745), 5 weeks after occlusion, was successful in 1 case. One dog was negative for sperm in the sixth ejaculate after the clips were removed 1 year after occlusion (1050).

Seven re-anastomosis procedures were attempted by Drs. Davis and Lee, four in aspermic animals and three in animals with sperm (as controls for the re-anastomosis technique; 843, 854 and 728). Two of the four re-anastomosis in aspermic dogs (1049 and 726) resulted in subsequent sperm in the sixth postoperative ejaculate At the time of sacrifice, however, sperm were seen in both the proximal and distal vas in one additional dog (745), suggesting that a more prolonged observation might have resulted in an appearance of sperm in the ejaculate. Of the three dogs who had been positive and underwent re-anastomosis, one (854) was rendered aspermic after this event, with no sperm found in either the proximal or distal vasa at sacrifice. Histological sections of the testes were taken at the time of sacrifice of all the dogs under study, and will be the subject of a subsequent report.

Adhesions: No significant adhesions or distortions were found at the operative site in the three dogs operated on 5 weeks after occlusion. Evaluation of adhesions and distortions at the operative site 1 year after surgery in the remaining dogs, revealed four vasa with adhesions out of the 14 observed, and observation suggesting that the procedure usually results in little scarring. A typical operative site is shown in Fig 4, a single clip on the vas of the dog which had to be sacrificed because of manage 6 weeks after vas occlusion.

Dislodged Clips: At the time of re-exploration, some clips were found lying adjacent to the vas, rather than across it. Six of such dislodged clips were observed out of a total of 23, or approximately 25 % of the clips were displaced. These displacements were presumable due to muscular contractions of the vas.

DISCUSSION

A consistent finding in this study is the ability of two clips on each vas to render the dog asperimic. These findings would suggest that the placement of a double clip on a vas, without division or further suturing, may provide a means of suspending male fertility in a way preserving the anatomy for subsequent reversal by means of re-anastomosis, should this be desired.

An observed 25% rate of dislodgement of the vas in this small series, however, suggests that a larger scale study would reveal a predictable failure rate (25 % of 25 % with two clips on a vas, or approximately 6 % failure rate), one which is nevertheless comparable to other forms of contraception as currently practiced except for perhaps the birth control pill and female sterilization.

The presence of large amounts of scar tissue in the operative region of vasocclusion is undesirable since it complicates the mobilization of the vas and successful approximation of the two cut ends should reanastomosis be desired. One of the more impressive findings of this preliminary study was the relative absence of tissue reaction in the majority of vasa occluded with tantalum clips along.

Technically reanastomosis was, therefore, accomplished more easily in these dogs than in human cases subsequent to standard vasectomy. The surgeons who performed the operations, Dr. Davis and Dr. Lee, note less scar tissue and greater ease in bringing the two cut vasa into opposition compared to reanastomosis efforts after standard vasectomy. This latter observation is especially important since there must be sufficient length of healthy proximal and distal vas available for mobilization for the delicate microsurgical reanastomosis.

The possibility that reversal of sterilization could be accomplished by a simple removal of the clip alone was not supported by these observations. Removal of the clip was accomplished with more difficulty than is required for application. In some cases fine dissection requiring considerable surgical skills was required to expose the clip.

The limitations of this study need to be mentioned to interpret the data in context. Fertility had not been documented before surgery or after attempts at reversibility, only the presence of mobile sperm. Thus, caution should be exercised in extrapolating these results to any clinical restoration of fertility. The absence of presurgical ejaculation was a flaw in experimental design which nevertheless allows only one observation to be questioned: Dog 1035 may have been aspermic from the begining; all other dogs proved to have sperm subsequently either in the ejaculate or in the vas at sacrifice. Finally, the numbers of each study group are small due to the exploratory nature of these studies; require larger scale evaluation to establish significance.

A cautiously optimistic interpretation of the data regarding the success after reanastomosis attempts in dogs rendered aspermic by clips for 1 year in perhaps justified. Within 5 weeks of such an attempt, two of the four dogs showed motile sperm in the ejaculate, and at sacrifice on other showed sperm in both the proximal and distal vas of at least one of the vasa reanastomosed.

A massive program of sterilization has already been implemented in India and other countries, and better techniques need to be developed. Should the methods by which sterilization is accomplished fall into disrepute, the effort for population planning would be dealt a major setback. There is already some indication in recent informal reports from India that the traditional technique of vasectomy is losing mass appeal. With the desire for a procedure, which is technically, simple, reversible, and free of complications, this report suggests a direction for future research to develop methods of male sterilization, which will accomplish these goals. The results here reported suggest that a technique such as the placement of two clips on the vas may render a male aspermic in such a manner as to make subsequent reanastomosis technically more feasible. The ultimate role of this approach in mass population planning efforts must await further laboratory and clinical trials.

SUMMARY AND CONCLUSION

1. A preliminary study evaluating the use of tantalum clips as vasocclusive device is reported.

2. Applying two clips on each vas resulted in total aspermia in six dogs.

3. Removal of the clips 5 weeks after vas occlusion resulted in the restoration of sperm to the ejaculate in one of the three dogs tested.

4. Removal of the clip was not as simple as it was hoped; in some cases scar tissue made the clip technically difficult to expose and remove.

5. In four dogs, in which reanastomosis was attempted after successful vasocclusion, sperm appeared in the ejaculate in two, and sperm was present in one vas at the time of sacrifice in one other (one dog became a pet and was not sacrificed).

6. The methods described may provide a better anatomic condition for a reanastomosis procedure than does the current method of vasectomy. This is because development of scar tissue is considerably less with the method described than with traditional methods. Available data suggest that the failure rate with two clips will probably be in the same range as standard contraceptive techniques.

7. The role of tantalum clips in occluding the vas for large-scale population planning programs must await further laboratory and clinical study.

REFERENCES

1. JHAVER P.S. Surgery of the epididymis and vas. J. Indian Med Ass 44 : 591, 1965.

2. SCHMIDT. S.S. Vasectomy: Indications, technique and reversibility. Fertil Steril 19 : 192, 1968.

3. TILAK G.H, Vasectomy by single midline scrotal invasion, J. Indian Med Ass 41: 548, 1963.

4. ARMSTRONG C.P Use of hemo-clip in urological procedures. Presented to Southeastern Section of the American Urological Association, Inc. April 13,1967.

5. PHADKE G.M. AND PHADKE, A.B. Experiences in the re-anastomosis of the vas deferens. J. Urol 97:888, 1967.

6. O’Conor V.J. Anastomosis of the vas deferens after purposeful division for sterility, J. Urol 59, 229, 1948.

7. DORSEY J.W Anastomosis of the vas deferens to correct post vasectomy sterility, J. Urol 70, 515, 1953.

8. HUMPHREYS R.H.Vas deferens anatomosis Western J Surg 61,658, 1953.

9. MASSEY B.D and Nation, E.F Vas deferens anastomosis, J Urol 61, 391, 1949.

10. MAURITZEN K. Anastomosis operations on the vas deferens, Acta Chir Scand 102, 457, 1952.

11. FREUND M, and DAVIS J.E. Disappearance rate of spermatozoa from the ejaculate following vasectomy. Fertil Steril 20,163,1969.

* Research was partly supported by grants from the Rockefeller Foundation. The Population Council, Inc. and United States Agency for International Development.

** Current address: “Mark Haven,” 24, Strand Road, Bombay 1, India

*** Address request for reprints to J.F. Hulka, M.D Room 403, School of Public Health, Chapel Hill, N.C 27514

**** Surgical Instrument Division, Edward Weck & Co, Inc. 49-33 31st place, Long Island City, N.Y 111010

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