Amy E. Pollack and Mark A. Barone
Table Of Contents
Amy E. Pollack, MD, MPH
Mark A. Barone, DVM, MS
PREOPERATIVE EVALUATION BEFORE VASECTOMY REVERSAL
FACTORS AFFECTING SUCCESS OF VASECTOMY REVERSAL
ASSISTED REPRODUCTION TECHNIQUES
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.
|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.
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.
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,
|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
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 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
|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
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.
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.
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.
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.
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.