Chapter 48
Reversing Vasectomy
Amy E. Pollack and Mark A. Barone
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Amy E. Pollack, MD, MPH
President, AVSC International, New York, New York (Vol 6, Chaps 47, 48, 49)

Mark A. Barone, DVM, MS
AVSC International, New York, New York (Vol 6, Chaps 47, 48, 49)

INTRODUCTION
PREOPERATIVE EVALUATION BEFORE VASECTOMY REVERSAL
FACTORS AFFECTING SUCCESS OF VASECTOMY REVERSAL
ASSISTED REPRODUCTION TECHNIQUES
CONCLUSION
REFERENCES

INTRODUCTION

The increased use of vasectomy has resulted in a higher frequency of requests for reversal. The most common procedure for reversal is reanastomosis of the cut ends of the vas, known as vasovasostomy. Occasionally vasoepididymostomy, or anastomosis of the vas directly to the epididymis, is done. Among the reasons men request vasectomy reversal are divorce from current partner, remarriage, loss of children, or change of mind.1,2,3 One study found that more than one half of men requesting reversal were divorced or separated and felt disadvantaged in finding new relationships because they were vasectomized or were remarried and wanted children with their new wife.3 In some cases, vasectomy reversal has been recommended or performed to relieve postvasectomy pain syndrome, which may be related, at least in part, to epididymal engorgement with sperm or sperm granuloma formation due to back-pressure-induced rupture of epididymal tubules.4,5,6

Theoretically, there is no reason that fertility should not be restored following vasectomy reversal, because significant impairment of spermatogenesis after vasectomy is extremely uncommon.7,8 Indeed, technical success (i.e. the reappearance of sperm in the ejaculate following reversal) is fairly high. However, in most cases, the desired endpoint of vasectomy reversal is pregnancy, and it must be emphasized that pregnancy rates are always lower than the rates of technical success. Technical factors in the reversal surgery itself present a challenge because the vas is thick-walled with a narrow lumen, and often the distal (testicular) end is dilated, leading to a pronounced difference in diameter of the proximal and distal lumens.2,9 In addition, other factors, including time since vasectomy until reversal is performed, secondary changes in the epididymis such as obstruction due to granuloma formation, presence of partial obstruction following reversal surgery, and levels of antisperm antibodies, may play a role in whether or not pregnancy is achieved following vasectomy reversal.

Those involved in screening and counseling men for vasectomy should carefully evaluate them to determine whether they are seeking vasectomy as a temporary measure, because the restoration of fertility cannot be assured. Men who have emotional problems or who desire vasectomy to improve an unstable marriage may be worse after the procedure and would be likely candidates to seek reanastomosis. Careful screening, counseling, and client selection should reduce the demand for reversal. However, vasectomy should be performed by the surgeon in such a way as to consider the possibility that the man might seek reversal in the future.

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PREOPERATIVE EVALUATION BEFORE VASECTOMY REVERSAL

Evaluation before vasectomy reversal should start with an interview with the client and, if possible, his female partner. Details regarding his original fertility status and details of the vasectomy, including date, procedure used (if the operative report is available or discussion with the original surgeon is possible), and complications, may provide important information regarding the chances of successful restoration of fertility. Important historical information should be obtained, including injuries or infections of the testicles or epididymis and general health problems such as urinary tract infections or diabetes. Physical examination should include palpation of the site of vasectomy. Nodularity in the convoluted vas or epididymis could diminish the possibility for successful reversal. The examination should evaluate the size, shape, and consistency of the testicles. When appropriate, the female partner should be advised to undergo a fertility investigation. The gynecologist should communicate with the operating surgeon regarding her status and her chances of pregnancy. Sometimes a man requests restoration of fertility for his own reasons, regardless of his partner or when he has no partner. As with vasectomy, such requests should be honored if there are no medical or other contraindications. The surgeon must be sure that the client understands that restoration of sperm to the ejaculate does not guarantee pregnancy and that the success of the technical procedure may not satisfy the ultimate desires of the couple.

Over the past several decades a number of techniques, including macroscopic and microsurgical approaches, have been used to perform vasectomy reversal. Regardless of what specific technique is used, the key to success is to accurately oppose the two ends of each vas to establish a watertight anastomosis that prevents sperm leakage and subsequent granuloma formation as well as allows for unobstructed flow of sperm.

Although patency and pregnancy rates may be high following macroscopic reversal when performed by some experienced providers, low rates have also been reported, and the current consensus is that results with microsurgical approaches are superior to those with macroscopic techniques, with or without the use of a magnifying loupe.1,10,11 Table 1 shows reported patency and pregnancy rates following macroscopic and microsurgical vasectomy reversal.

TABLE 1. Patency and Pregnancy Rates Following Vasectomy Reversal


 

No. of

Patency

Pregnancy

Reference

Cases

(%)

(%)

Macroscopic Approaches

 

 

 

Lee and McLoughlin (1980)12

41

90

46

Fallon et al (1981)13

36

74

57

Kessler and Feiha (1981)14

83

92

45

Urquhart-Hay (1981)15

50

84

52

Soonawalla and Lal (1984)16

194

81

44

Lee (1986)17

300

84

35

Middleton et al (1987)18

73

81

45

Meinertz et al (1990)19

145

90

53

Mason et al (1997)20

66

74

41

Microsurgical Approaches

 

 

 

Lee and McLoughlin (1980)12

26

96

54

Cos et al (1983)21

87

75

46

Soonawalla and Lal (1984)16

339

89

63

Owen and Kapila (1984)2

475

93

82

Lee (1986)17

324

90

51

Silber (1989)22

282

91

81

Belker et al (1991)1

1012

86

52

Fox (1994)23

103

~90

48

Huang et al (1997)24

56

100

66

Takihara (1998)25

29

81

38

The two main methods of microsurgical reversal are two-layer anastomosis and modified one-layer anastomosis. Both involve placement of interrupted sutures using an operating microscope. Sutures should be fine and nonirritating (e.g. 9–0 or 10–0 nylon). With two-layer anastomosis, sutures are first placed in the mucosal layer, and then a second set of sutures is placed in the muscle layer. The modified one-layer approach involves placement of several full-thickness sutures, followed by additional sutures through the muscle layer only which are placed between the full-thickness sutures.26 Similar results have been reported using the two-layer and modified one-layer approaches (Table 2). The modified one-layer approach may be beneficial in that it takes less time. However, the two-layer approach allows for better apposition of the cut ends of the vas in cases in which there is a large difference in the diameters of the cut ends.

TABLE 2. Patency and Pregnancy Rates for Two-Layer Compared With Modified One-Layer Microsurgical Vasectomy Reversal


 

Two-Layer

Modified One-Layer

Reference

Patencya

Pregnancya

Patencya

Pregnancya

Sharlip

100%

75%

100%

67%

 (1981)27

 

 

 

 

Lee (1986)17

91%

52%

85%

50%

Belker

86%

51%

89%

57%

 (1991)1

 

 

 

 

Takihara

83%

42%

79%

33%

 (1995)28

 

 

 

 


a Differences are not significant

During vasectomy reversal procedures, the surgeon should perform a microscopic examination of the fluid obtained from the testicular end of the vas. Temporary muscle spasm may prevent the initial exudation of fluid. In some cases, gently massaging the vas, probing the lumen, or irrigating with saline may initiate the flow. The character of the fluid may provide some indication of the likelihood of success of the reversal and may also influence the decision to do a vasoepididymostomy as opposed to a vasovasostomy. If sperm (either motile or nonmotile) are present in the intraoperative vas fluid, then vasovasostomy is performed for vasectomy reversal. This usually indicates a good prognosis and early appearance of sperm in the ejaculate. If sperm are not present in the vas fluid but the fluid appears watery (i.e. clear, colorless, and transparent), vasovasostomy should still be the procedure of choice, because sperm often reappear in the ejaculate with time in these cases.1,29 When sperm are absent from the vas fluid and the fluid appears cloudy or is creamy or paste-like in consistency, then vasoepididymostomy may afford a higher chance of success.26,30 Vasoepididymostomy is a technically demanding microsurgical procedure, in part because it may be difficult to identify the proper epididymal tubules that lead to the testis and because of the large difference in diameter between the vas and epididymal tubule.25 Nonetheless, although success rates are lower than those for vasovasostomy, reasonable success can be achieved following vasoepididymostomy. Patency rates have been reported to range from 55% to 85%, with pregnancy rates being in general much lower.30,31,32,33,34 Although pregnancy rates following vasoepididymostomy have been reported as high as 42% to 55%,22,31,33,35 most often they are in the range of 10% to 30%.25,30,32,34 Unlike vasovasostomy, if no sperm are seen intraoperatively from fluid or a touch preparation obtained from the epididymis during vasoepididymostomy, the chance of successful reversal is minimal.11,34,36,37,

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FACTORS AFFECTING SUCCESS OF VASECTOMY REVERSAL

Time Between Vasectomy and Vasectomy Reversal

Silber29 first reported that one of the most important factors influencing return of fertility after vasectomy reversal was the duration of time the vasa deferentia had been obstructed. The longer the interval between vasectomy and reversal, the less likely the reversal was to be a success.

The Vasovasostomy Study Group reported that if the interval was less than 3 years, patency occurred in 97% of cases and pregnancy in 76%; with a 3- to 8-year interval, patency occurred in 88% and pregnancy in 53%; with a 9- to 14-year interval, patency occurred in 79% and pregnancy in 44%; and with a 15-year interval or more, patency occurred in 71% and pregnancy in 30%.1 Other researchers have seen similar results, with reported pregnancy rates of 42% to 64% when vasectomy was performed less than 10 years before reversal, compared with 0% to 39% when vasectomy was performed more than 10 years before reversal.23,24,25,28

The most likely explanation for the effect of time since vasectomy on the success of reversal is that with increasing time the chances are greater that back pressure from the site of the vasectomy will lead to rupture of epididymal tubules, with subsequent development of sperm granulomas and obstruction of the epididymis.38,39

Antisperm Antibodies

The production of antisperm antibodies after vasectomy (see Chap. 6-49) has implications for the success of reversal. Several investigators have reported a clear association between seminal plasma antisperm antibodies and reduced pregnancy rates,19,24,40,41 whereas others have questioned the importance of antisperm antibodies in reduced fertility after reversal.42,43 In vitro, antisperm antibodies have been shown to impair sperm motility and cervical mucus penetration.44,45,46,47 In addition, using computerized semen analysis, sperm from men with antisperm antibodies was shown to have significantly lower percentages of motility, velocity, and linearity compared with sperm from men without antibodies.48 With videomicrographic semen analysis, the percentage of motile sperm was found to be significantly lower among men with greater quantities of sperm surface antibodies postvasectomy.49

Although there have been differing reports and the exact effect of antisperm antibodies on fertility is not clear, the current consensus is that only high levels of antisperm antibodies inhibit fertility after vasectomy reversal.50 In addition, it appears that the class of antibody is more important than the antibody titers themselves. Men with IgG antisperm antibodies and without any IgA antisperm antibodies were shown to have no impairment of fertility, even when 100% of the sperm were found to have IgG on their surface.19 Conversely, fertility was impaired in men with IgA antisperm antibodies, indicating that this class of antibody interferes with sperm function. Studies by others support this finding and have shown that IgA is the important class of antisperm antibodies affecting sperm function in vitro.47,51,52 However, one report is at odds with these findings, showing that IgG antisperm antibodies in seminal plasma had a negative effect on fertility compared with seminal plasma from men having no antisperm antibodies or IgA antibodies.53

It is not possible to accurately predict results of vasectomy reversal based on prereversal antisperm antibody levels in serum, and reversal surgery itself can induce the production of antisperm antibodies.53,54

Partial Obstruction

Partial obstruction of the vas at the site of the vasectomy reversal has been proposed as a factor contributing to failure of vasectomy reversal.10,43 Sperm may leak out at the site of vasovasostomy, leading to sperm granuloma formation and partial obstruction of the vas. Although these cases may be technical successes (i.e. sperm is present in the semen), the sperm may be poor quality in terms of concentration and motility.

Results of a recent study demonstrated that partial obstruction plays a role in infertility following vasectomy reversal, even though men may also have antisperm antibodies.55 In men with partial obstruction (defined as epididymal fullness on palpation) and moderate levels of antisperm antibodies who underwent a repeat microsurgical vasectomy reversal, motility improved from a mean of 4% to 52%, and mean sperm concentration increased from 17 × 106 to 36 × 106 sperm/ml. One half of the men and their partners achieved a pregnancy after the repeat surgery. Good results in terms of both patency and pregnancy have been reported by others following repeat vasectomy reversal surgery.1,10,29

It is likely, however, that antisperm antibodies play a significant role in persistent infertility following vasectomy reversal in men who have high antisperm antibodies titers, poor sperm motility, and low sperm counts; repeat reversal surgery is not recommended in these cases.11,55

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ASSISTED REPRODUCTION TECHNIQUES

Retrieval of sperm from the epididymis or the testis, followed by intracytoplasmic sperm injection (ICSI), has been used successfully to produce offspring by men who do not want a vasectomy reversal or who have had one or more unsuccessful reversal surgeries. Success rates have been shown to be comparable to those following ICSI with ejaculated sperm.56,57,58 Sperm can be retrieved from the epididymis using microscopic or percutaneous aspiration. Success rates in terms of retrieving sperm that can be used for ICSI following epididymal sperm aspiration are generally in the neighborhood of 80% or higher.59,61 Pregnancy rates following ICSI are reported to be between 25% and 36%.59,61,62,63 Percutaneous epididymal sperm aspiration has advantages over microsurgical epididymal sperm aspiration; it is simpler, requires less time and no specialized equipment, causes less discomfort, and can be performed under local anesthesia.

Pregnancy rates following ICSI with sperm aspirated directly from the testis or from testicular biopsy specimens range from 17% to 36% and have been reported to be as good as those following microsurgical epididymal sperm aspiration58,62,64 and percutaneous epididymal sperm aspiration.59,60

Vasovasostomy and vasoepididymostomy have been shown to be more successful and less costly than ICSI following microsurgical epididymal sperm aspiration. Thus, surgical reversal appears to be a better first choice for vasectomized men who wish to have children.33 This is the case even in men who are undergoing repeat vasectomy reversal surgery due to a previous failed reversal.65

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CONCLUSION

Research continues on new and improved methods of vasectomy reversal that may be easier to perform or that may provide better success rates than current approaches. Laser-assisted techniques have shown good preliminary success in both animals and humans, and one technique has been approved for use in humans by the U.S. Food and Drug Administration.66,67,68,69 A simpler technique using fibrin tissue adhesives has been demonstrated to be as effective as microsurgical approaches in animal models.68,70 Nonetheless, it should be emphasized that vasectomy is meant to be a permanent method of contraception and that reversibility with the endpoint of pregnancy cannot be guaranteed.

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REFERENCES

1. Belker AM, Thomas Jr AJ, Fuchs EF et al: Results of 1,469 microsurgical vasectomy reversals by the Vasovasostomy Study Group. J Urol 145: 505, 1991.

2. Owen E, Kapila H: Vasectomy reversal: Review of 475 microsurgical vasovasostomies. Med J Aust 140: 398, 1984.

3. Howard G: Who asks for vasectomy reversal and why? BMJ 285: 490, 1982.

4. Myers SA, Mershon CE, Fuchs EF: Vasectomy reversal for treatment of the post-vasectomy pain syndrome. J Urol 157: 518, 1997.

5. Temmerman M, Cammu H, Devroey P et al: Evaluation of one-hundred open-ended vasectomies. Contraception 33: 529, 1986.

6. Schmidt SS: Spermatic granuloma: An often painful lesion. Fertil Steril 31: 178, 1979.

7. Bagshaw HA, Masters JRW, Pryor JP: Factors influencing the outcome of vasectomy reversal. Br J Urol 52: 57, 1980.

8. Royle MG, Hendry WF: Why does vasectomy reversal fail? Br J Urol 57: 780, 1985.

9. Silber SJ: Microsurgery for male infertility. Microsurgery 9: 251, 1988.

10. Fox M: Failed vasectomy reversal: Is a further attempt worthwhile using microsurgery? Eur Urol 31 (4): 436, 1997.

11. Belker AM: Evaluation of partial anastomotic obstruction after vasovasostomy and predictors of success after vasoepididymostomy. J Urol 159: 835, 1998.

12. Lee L, McLoughlin MG: Vasovasostomy: A comparison of macroscopic and microscopic techniques at one institution. Fertil Steril 33: 54, 1980.

13. Fallon B, Miller RK, Gerber WL: Nonmicroscopic vasovasostomy. J Urol 126: 361, 1981.

14. Kessler R, Freiha F: Macroscopic vasovasostomy. Fertil Steril 36: 531, 1981.

15. Urquhart-Hay D: A low power magnification technique for reanastomosis of the vas. Br J Urol 53: 466, 1981.

16. Soonawalla FB, Lai SS: Microsurgery in vasovasostomy. Indian J Urol 1: 104, 1984.

17. Lee HY: A 20 year experience with vasovasostomy. J Urol 136: 413, 1986.

18. Middleton RG, Smith JA, Moore MH et al: A 15 year follow-up of a non-microsurgical technique for vasovasostomy. J Urol 187: 886, 1987.

19. Meinertz H, Linnet L, Fogh-Andersen P et al: Antisperm antibodies and fertility after vasovasostomy: A follow-up study of 216 men. Fertil Steril 54: 315, 1990.

20. Mason RG, Connell PG, Bull JC: Reversal of vasectomy using a macroscopic technique: A retrospective study. Ann R Coll Surg Engl 79 (6): 420, 1997.

21. Cos LR, Valvo JR, Davis RS et al: Vasovasostomy: Current state of the art. Urology 22: 567, 1983.

22. Silber SJ: Results of microsurgical vasoepididymostomy: Role of epididymis in sperm maturation. Hum Reprod 4: 298, 1989.

23. Fox M: Vasectomy reversal—Microsurgery for best results. Br J Urol 73: 449, 1994.

24. Huang MK, Wu XQ, Fu CS et al: Multiple factors affecting human repregnancy after microsurgical vasovasostomy. Reprod Contracept 8: 92, 1997.

25. Takihara H: Treatment of obstructive azoospermia in male infertility—Past, present, and future. Urology 51: 150, 1998.

26. Donovan Jr JF: Microscopic vasovasostomy: current practice and future trends. Microsurgery 16: 325, 1995.

27. Sharlip ID: Vasovasostomy: Comparison of two microsurgical techniques. Urology 17: 347, 1981.

28. Takihara H, Imoto K, Shirataki S et al: Microsurgical repair of the obstructive causes of male infertility. Nishinihon J Urol 57: 421, 1995.

29. Silber SJ: Microscopic vasectomy reversal. Fertil Steril 28 (1): 1191, 1977.

30. Jarow JP: Epididymovasostomy. Microsurgery 16: 333, 1995.

31. Marmar JL: Management of the epididymal tubule during an end-to-side vasoepididymostomy. J Urol 154: 93, 1995.

32. Matthews GJ, Schlegel PN, Goldstein M: Patency following microsurgical vasoepididymostomy and vasovasostomy: Temporal considerations. J Urol 154: 2070, 1995.

33. Kolettis PN, Thomas Jr AJ: Vasoepididymostomy for vasectomy reversal: A critical assessment in the era of intracytoplasmic sperm injection. J Urol 158: 467, 1997.

34. Berardinucci D, Zini A, Jarvi K: Outcome of microsurgical reconstruction in men with suspected epididymal obstruction. J Urol 159: 831, 1998.

35. Thomas AJ Jr: microsurgical end-to-side vasoepididymostomy: Analysis of the outcome of 141 procedures. J Urol 149: 436A, 1993.

36. Niederberger C, Ross LS: Microsurgical epididymovasostomy: predictors of success. J Urol 149: 1364, 1993.

37. Jarow JP, Sigman M, Buch JP et al: Delayed appearance of sperm after end-to-side vasoepididymostomy. J Urol 153: 1156, 1995.

38. Silber SJ: Epididymal extravasation following vasectomy as a cause for failure of vasectomy reversal. Fertil Steril 31: 309, 1979.

39. Hendry WF: Vasectomy and vasectomy reversal. Br J Urol 73: 337, 1994.

40. Fuchs, EF, Alexander NJ: Immunologic considerations before and after vasovasostomy. Fertil Steril 40: 497, 1983.

41. Sutherland PD, Matson PL, Masters JR et al: Association between infertility following reversal of vasectomy and the presence of sperm agglutinating activity in semen. Int J Androl 7: 503, 1984.

42. Newton RA: IgG antisperm antibodies attached to sperm do not correlate with infertility following vasovasostomy. Microsurgery 9: 278, 1988.

43. Thomas AJ Jr, Pontes JE, Rose NR et al: Microsurgical vasovasostomy: Immunologic consequences and subsequent fertility. Fertil Steril 35: 447, 1981.

44. Clarke GN: Immunoglobulin class and regional specificity of antispermatozoal autoantibodies blocking cervical mucus penetration by human spermatozoa. Am J Reprod Immunol Microbiol 16: 135, 1988.

45. Barratt CLR, Dunphy BC, McLeod I et al: The poor prognostic value of low to moderate levels of sperm surface-bound antibodies. Hum Reprod 7: 95, 1992.

46. Wang C, Baker HWG, Jennings MG et al: Interaction between human cervical mucus and sperm surface antibodies. Fertil Steril 44: 484, 1985.

47. Kremer J, Jager S: Characteristics of anti-spermatozoal antibodies responsible for the shaking phenomenon with special regard to immunoglobulin class and antigen-reactive sites. Int J Androl 3: 143, 1980.

48. Check JH, Adelson HG, Bollendorf A: Effect of antisperm antibodies on computerized semen analysis. Arch Androl 27: 61, 1991.

49. Broderick GA, Tom R, McClure RD: Immunologic status of patients before and after vasovasostomy as determined by the immunobead antisperm antibody test. J Urol 142: 752, 1989.

50. Lea IA, Adoyo P, O'Rand MG: Autoimmunogenicity of the human sperm protein Sp17 in vasectomized men and identification of linear B cell epitopes. Fertil Steril 67: 355, 1997.

51. Hendry WF, Stredronska J, Lake RA: Mixed erythrocyte-spermatozoa antiglobulin reaction (MAR test) for IgA antisperm antibodies in subfertile males. Fertil Steril 37: 108, 1982.

52. Parslow JM, Poulton TA, Besser GM et al: The clinical relevance of classes of immunoglobulins on spermatozoa from infertile and vasovasostomized males. Fertil Steril 43: 621, 1985.

53. Matson PL, Junk SM, Masters JR et al: The incidence and influence upon fertility of antisperm antibodies in seminal fluid following vasectomy reversal. Int J Androl 12: 98, 1989.

54. Kay DJ, Clifton V, Taylor JS et al: Anti-sperm antibodies and semen profiles in re-anasatomosed men. Reprod Fertil Dev 5 (1): 135, 1993.

55. Carbone Jr DJ, Shah A, Thomas Jr AJ et al: Partial obstruction, not antisperm antibodies, causing infertility after vasovasostomy. J Urol 159: 827, 1998.

56. Mansour RT, Aboulghar MA, Serour GI et al: Intracytoplasmic sperm injection using microsurgically retrieved epididymal and testicular sperm. Fertil Steril 65: 566, 1996.

57. Silber SJ, Van Steirteghem AC, Liu J et al: High fertilization and pregnancy rate after intracytoplasmic sperm injection with spermatozoa obtained from testicle biopsy. Hum Reprod 10: 148, 1995.

58. Abuzeid MI, Sasy MA, Salem H: Testicular sperm extraction and intracytoplasmic sperm injection: A simplified method for treatment of obstructive azoospermia. Fertil Steril 68: 328, 1997.

59. Craft IL, Khalifa Y, Boulos A et al: Factors influencing the outcome of in-vitro fertilization with percutaneous aspirated epididymal spermatozoa and intracytoplasmic sperm injection in azoospermic men. Hum Reprod 10: 1791, 1995.

60. Meniru GI, Gorgy A, Podsiadly BT et al: Results of percutaneous epididymal sperm aspiration and intracytoplasmic sperm injection in two major groups of patients with obstructive azoospermia. Hum Reprod 12: 2443, 1997.

61. Craft I, Tsirigotis M, Bennett V et al: Percutaneous epididymal sperm aspiration and intracytoplasmic sperm injection in the management of infertility due to obstructive azoo-spermia. Fertil Steril 63: 1038, 1995.

62. Aboulghar MA, Mansour RT, Serour GI et al: Fertilization and pregnancy rates after intracytoplasmic sperm injection using ejaculate semen and surgically retrieved sperm. Fertil Steril 68: 108, 1997.

63. Dohle GR, Ramos L, Pieters MH et al: Surgical sperm retrieval and intracytoplasmic sperm injection as treatment of obstructive azoospermia. Hum Reprod 13: 620, 1998.

64. Watkins W, Nieto F, Bourne H et al: Testicular and epididymal sperm in a microinjection program: Methods of retrieval and results. Fertil Steril 67: 527, 1997.

65. Donovan Jr JF, DiBaise M, Sparks AE et al: Comparison of microscopic epididymal sperm aspiration and intracytoplasmic sperm injection/in-vitro fertilization with repeat microscopic reconstruction following vasectomy: Is second attempt vas reversal worth the effort? Hum Reprod 13: 387, 1998.

66. Mingin GC, Ditrolio JV: Vasovasostomy using albumisol solder with an argon laser. Br J Urol 81: 628, 1998.

67. Shanberg A, Tansey L, Baghdassarian R et al: Laser-assisted vasectomy reversal: experience in 32 patients. J Urol 143: 528, 1990.

68. Ball RA, Steinberg J, Wilson LA et al: Comparison of vasovasostomy techniques in rats utilizing conventional microsurgical suture, carbon dioxide laser, and fibrin tissue adhesives. Urology 41: 479, 1993.

69. Seaman EK, Kim ED, Kirsch AJ et al: Results of laser tissue soldering in vasovasostomy and epididymovasostomy: experience in the rat animal model. J Urol 158: 642, 1997.

70. Vankemmel O, Rigot JM, Burnouf T et al: Delayed vasal reanastomosis in rats: Comparison of a microsurgical technique and a fibrin-glued procedure. Br J Urol 78: 271, 1996.

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