Typically it will take 12 months to achieve a pregnancy after a vasectomy reversal although some will happen sooner and some (much) later. Some couples even report a positive test even before their post-reversal sperm count.
Success depends on three main factors:
- The interval between vasectomy and request for reversal – usually known as the ‘obstructive interval’. The results are best when the reversal is undertaken relatively soon after the initial vasectomy (see below).
- The way the vasectomy was performed. Most are fairly standard but sometimes large amounts of vas tubing have been removed or heat (cautery) has been used to seal and destroy the tube. Some vasectomy doctors for convenience make the site of the vasectomy way too low and this can make the reversal trickier. Occasionally a previous hernia operation as a child can snag the tubes in the groin.
- The age of the female partner. Success rates are better when she is below 30 yr compared to when above. Just because a woman is over 35 yr does not neccesarily preclude a successful reversal. The success rate is significantly lower when she is over 40 yr See the blog for specific topics on this aspect.
- The presence of a small lump on the vas tubing called a sperm granuloma– this can improve the success rate
- The way the reversal is performed and by whom. There is no doubt that the success rates are MUCH better when microsurgery is used. Microsurgery is now the standard of care.
In the UK you should choose a surgeon who is a member of the British Association of Urological Surgeons. By seeking out such an individual you are best placed to ensure your surgeon is professionally trained and qualified. He or she should confirm they are experienced in microsurgery and be willing to share their results with you. That person may have been recommended to you by a friend or colleague.
The man’s age can subtly influence success rates, how long it takes to produce a pregnancy and also increase the risk of certain conditions that affect children (see more detailed information in the blog) (see blog)
The female partner’s age and fertility / menstrual history are more important. Clearly she needs to be ‘fertile’ and if in doubt she should be checked out before you consider a reversal procedure. Again see our blog for specific topics.
Previous testicular infection or sexually transmitted diseases may reduce male infertility. Hernia surgery or late testicular descent (known as an undescended testis) may also be important.
Published success rate in the press tend to refer to the patency rate (a positive sperm count with swimming sperm identified in the sample): this is generally quoted as it provides a reflection of the surgical technique. A good benchmark for microsurgical vasectomy reversal outcomes is provided by the British Association of Urological Surgeons below:
Time since vasectomy Sperm present
under 3 years 97%
3 – 8 years 88%
9 – 14 years 79%
15 – 19 years 70%
more than 19 years 40%
A recent audit of Mr McLoughlin’s available outcome data (December 2016) showed that overall, 93% (*) of men had a successful outcome after a first attempt at reversal across. For the groups of men with shortened intervals, his success rates were higher than 94% (*).
It is important to realise that the PREGNANCY rate will differ from the quoted success rate, as gauged by a positive sperm count after the reversal operation. Typically the rate is 55-60% of the success rate, but this is dependant on a number of other factors including your parter’s (female’s) age. Refer to the blog for more on the influence of partner’s age.
The (*) figure refers to the percentage of successful outcomes, defined as either a positive sperm count after a FIRST attempt at reversal and/or confirmation of a pregnancy or a live birth. When offering a vasectomy reversal service on a UK- wide or European level it can be challenging to obtain good quality patient outcome data as not all couples are contactable so to overcome this we:
- Collate all sperm count results coming through our own local lab – a positive sperm count refers to good numbers of swimming sperm on testing, whilst a negative refers to the absence of viable, swimming sperm on a post-reversal sperm count. We do not manipulate data by including only those men where sperm were identified during their surgery as some do, because this may bias results and over-inflate outcomes.
- For patients from further afield (where we are expecting them to supply their sperm count to the local hospital), we write to their GP at around 4 months if we have not heard an outcome and request a copy of the results to be posted to us for audit purposes. Alternatively we re-request that a count be done if needs be.
- Where a couple’s testimonial / letter or GP reports a post-reversal pregnancy or live birth, we include this in the figure for BOTH positive sperm count outcomes and also for positive pregnancy outcome, even if we have no proof of a positive sperm count. This is valid we feel as, on the balance of probabilities, it seems very likely that if a pregnancy has followed the reversal then a positive sperm count would also have been achieved. This happens on occasion, typically when pregnancy occurs quickly after the reversal and before the post-op sperm count is even due.
- Where neither the couple nor the GP respond, we do not include this patient in our data analysis. There is a risk that this may introduce positive bias and lead us to over-estimate our success rate, but over the years we have heard from patients at a much later date regarding pregnancies (usually post delivery of their baby!) under such circumstances. We have formed the view that failure to make contact does not neccesarily infer operative failure. This scenario accounts for only a small proportion of our workload.
It remains our belief that surgeons should be willing to communicate clearly and honestly with couples regarding vasectomy reversal reading the chances of success so that they can make their best choice at the outset.
HOW DO YOU INTERPRET A SPERM COUNT AFTER VASECTOMY REVERSAL ?
A recent paper has helped clarify this question (Vasectomy reversal semen analysis: new reference ranges predict pregnancy. Majzoub A et al Cleveland Clinic US Fertil Steril. 2017 Apr;107(4):911-915.)
They found significantly lower post-reversal semen parameters may be sufficient in previously fertile patients after reversal to produce a pregnancy, compared with the normal population
Established a reference range for post-operative semen tests to identify the minimum values associated with subsequent pregnancy.
Spontaneous pregnancy was reported for men with:
LOWER SPERM COUNTS : 15% with a sperm concentration of <5 million/mL
LOWER MOTILITY : 21.3% with a sperm motility of <10%
INCREASED ABNORMAL SHAPED SPERM : 14.8% of patients with a normal morphology of <1%
To put it another way… the lowest value at which pregnancy followed was:
VOLUME OF SEMEN to establish a spontaneous pregnancy was 0.74ml seminal fluid
SPERM CONCENTRATION was 3.56 million /ml
TOTAL MOTILITY was 4.45%
TOTAL MOTILE SPERM CONCENTRATION was 0.58 million / ml
NORMAL MORPHOLOGY was 0%
Compared to WHO standard NORMAL values:
VOLUME OF SEMEN 1.5ml
SPERM CONCENTRATION was 15 million /ml
TOTAL MOTILITY was 40%
NORMAL MORPHOLOGY was 4%
——————————————————————————————————————
For the interested reader, we include below an abridged (much shortened) version of a paper that appears in the ongoing professional update series of the British Association of Urological Surgeons Accepted 2017 and due for release late 2017. It has many techincal terms and abbreviations but does provide a lot more infirmation for those who want to read it!
Factors that influence outcome of vasectomy reversal
Defining ‘success’ following reversal:
Tubal patency rates, as evidenced by a positive sperm count following reversal, differ from success, as gauged by pregnancy rates for several reasons. Tubal patency rates are the most commonly quotes outcomes used in internet-focussed advertising campaigns as they are easier to collect and are both surgeon dependent / female-fertility independent. Such disparity must be clearly explained to couples. There are a number of reasons why such differences occur. Firstly, not all couples are biologically compatible. Secondly, female specific factors such as poor ovarian reserve in older partners, or unrelated sub-fertility issues may adversely influence outcomes. Lastly, it may be difficult to contact the patient years after surgery to determine pregnancy rates, which in turn potentially introduces observation bias. The exact definition of tubal patency in terms of ‘positive’ sperm counts is also somewhat variable, some referencing the presence of any motile sperm on microscopy in the ejaculate, while others have defined success arbitrarily as ‘over 10,000 sperm/ml of ejaculate in at least one semen analysis’. There currently appears no universal definition of success for tubal potency.
An equally important measure relates to post-reversal pregnancy rates compared with IVF/ICIS outcomes. How many cycles should be compared? Malizia et al proposed comparison with cumulative live birth over 6 cycles but it is unlikely that most UK couples seeking ART achieve this. An optimal comparison would be between IVF/ICSI sperm-extracted live births vs live-birth rates occurring any point down the line after vasectomy reversal.
Male factors
The obstructive interval and the question of Vv vs VE:
Silber was the first to describe in detail the influence of the obstructive interval between vasectomy and attempted reversal on the outcome. The Vasovasostomy Study Group (VVSG) identified a gradual downward trend in patency rates rather than a steep drop, although the rate of decline has been shown separately to accelerate after 15 years. To illustrate the phenomenon consider the American Society of Reproductive Medicine (ASRM) data that reported patency rates of 97%, 88%, 79% and 71% for intervals of <3 yr, 3-8yr, 9-14yr and ≥ 15 yr respectively. Pregnancy rates over the same intervals were 76%, 53%, 44% and 30%. Similarly in their series, Kolettis et al reported patency/pregnancy rates of 74%/40%, 87%/36% and 75%/27% for 10-15 yr, 16-19yr and 20yr or over. Even at 15 years, reversal-related success rate are still considered superior to the 20-37% rate per IVF-ISCI cycle. One of the issues with presenting such data to patients is that they can be no more than be a guide. It should be incumbent on the surgeon to offer his own personal outcome data.
The influence of longer obstructive intervals may reflect an increased risk of proximal obstruction resulting from epididymal ‘blow outs’ over time, along with epididymal dysfunction (in turn leading to reduced motility, either directly or indirectly as a result of obstructive interval or male age. This effect plateaus about 22yr after surgery and beyond, as protective mechanisms start to offset the impact, the end result being that about 25% of men will not require a VE.
Silber’s later data again confirmed the influence of obstructive interval on outcomes (98% tubal patency rates under 10 yr vs 93% for those over 10yr), but also highlighted that where VE was considered an option, obstructive interval became less important (as it potentially overcame the influence of epididymal obstruction in the equation). However, whilst the ability to perform VE certainly improves outcomes in men with long obstructive intervals, it does not eliminate obstructive interval as an important predictor of success; patency rates for either bilateral VE or VE in a solitary testis are good, but still significantly lower than the best VV patency rates. Furthermore, pregnancy rates even in those who achieve patency with VE are half those of VV on at least one side.
The epididymal function is affected by long obstructive intervals. Mui et al postulated that while spermatogenesis is maintained, epididymal dysfunction led to reduced sperm motility. Indeed, motility may reduce by as much as 1.3 million motile sperm/ejaculate/year after vasectomy.
The male partner’s age:
Older men tend to have longer obstructive intervals, but once this association has been removed the man’s age has little, if any, influence on patency rates. The effects of age on pregnancy rates are of more interest, however, as partners of males aged over 40yr experience delayed conception, one study finding pregnancy was 30% less likely compared to those under 30yr. This observation may in part be explained by reduced sperm motility/ progressive motility (falling by 0.7%/ 3.1% yr of age) which has been a consistent association with advancing age as a result of epididymal dysfunction or possibly altered accessory sex gland function in older men. It is possible that altered seminal glucosidase, PSA, zinc, and fructose levels are also implicated in reduced motility.
Older men also have increased numbers of DNA sperm mutations. Singh et al identified greater DNA damage in men between 36-57yr compared to those of 20-35yr, potentially in part accounting for increased rates of autism, schizophrenia or first-trimester spontaneous abortion observed with older fathers. Babies born to older couples (over 35yr) have increased rates of Down syndrome, the risk being highest where both parents are older and the mother is over 40yr. An age gap between partners may also be influential, with couples where the paternal age was more than five years older than the female’s experiencing lower pregnancy rates compared to those groups where both partner’s ages were close.
The original vasectomy:
It would intuitively make sense that the site of vasal division may influence the outcome. Witt et al found that a vasal remnant of greater than 2.7cm on the testicular side predicted a 94% chance of success, compared to 85% where shorter lengths were encountered. Whilst this may be logical (as the smaller the calibre of tubing, the greater the technical difficulty), this has not been proven elsewhere. Lower sited vasectomies on the convoluted tubules can be technically more challenging, but are not actually associated with lower success rates than where the site is on the straight portion (98% vs 97% respectively). Excision of a longer vasal segment generally requires the greater mobilisation of tissues and runs a higher risk of vascular injury to the vasal blood supply, as could over indulgent use of diathermy.
Previous male paternity:
Whilst a history of male fertility prior to vasectomy does not predict better outcomes (as most men undergoing vasectomy have already had children), the absence of previous fatherhood certainly requires clarification as to whether this was planned or not.
Anti-sperm antibodies:
The impact of anti-sperm antibodies appears to have been previously overestimated. Carbone et al concluded that the presence of anti-sperm antibodies (or their treatment) in persistently infertile post-reversal cases did not impact outcomes and that a repeat reversal was actually a better option. It is recognised that 60% of men develop these following vasectomy, but as their presence did not influence outcome the American Society of Reproductive Medicine no longer recommends testing prior to vasectomy reversal.
Smoking:
Smoking may lead to altered semen quality, but it is the effect of paternal smoking, effectively introducing passive smoking into the pregnancy (and with it the increased associated risk of low birth weight and stillbirths), that is most notable.
Testosterone use:
Social use of testosterone supplement therapy in the younger adults can impair spermatogenesis and with it outcomes
A previous reversal attempt:
A previous failed attempt at vasectomy reversal makes surgery more challenging. Repeat procedures have lower associated patency (79-92%) and pregnancy rates ( 31-52%). Increasing maternal age has a negative effect but not the obstructive interval. This could be explained by the increased requirement of VE at repeat surgery (especially where the absence of sperm had been confirmed by intra-operative examination (indicating previously unidentified epididymal obstruction. Silber claimed that the incorporation of VE into his algorithm for re-do reversal led to similar outcomes as for primary procedures. However, the proportion of patients that require a VE does vary widely depending on the reference source, ranging from 75% on at least one side, 47% down to 30%. Indeed, one series recommend repeating VV for all re-do surgery, even where sperm was absent from intra-operative vasal fluid. There is also evidence that where the reason for initial failure is one of poor VV technique, that repeating the VV offers superior results. A second VE after an initial failed VE may still be of value, although technically challenging, to say the least.
Previous inguinal surgery:
Intuitively, prior hernia surgery or orchidopexy could be considered a risk factor for vasal injury, however, the evidence shows this not to be the case with the risk being small.
Female factors
Gynaecological conditions such as pelvic inflammatory disease or endometriosis may impact pregnancy rates following an apparently successful vasectomy reversal. Previous fertility has a positive predictive value; pregnancy rates for couples where the female partner has been pregnant in a previous relationship are higher (57%) than those where no pregnancy was recorded (49%).
The woman’s age
As a woman ages, her ovarian reserve and egg quality will reduce, a woman in her 20’s having a 20% chance/month of becoming pregnant with regular unprotected intercourse. In her 30’s, the chance for pregnancy falls to 10%/month and by 40yr to 4%/month. This age-related influence also holds true after a reversal and, if anything, assumes greater importance in an era where the surgeon can potentially overcome the influence of a prolonged obstructive interval. Pregnancy rates described by Silber are frequently quoted, but have been questioned; he reported single operator pregnancy rates of 94% for women less than 30yr, 91% for those aged 30-35yr, 82% for the 35-40yr age group, including 61% for females aged over 40yr. Other series have failed to replicate these pregnancy rates, despite comparable or better patency rates. For example, Gerrard et al achieved pregnancy rates of 67%, 52%, 57%, 54% in age groups 20-24yr, 25-29yr, 30-34yr and 35-49yr respectively. In this series pregnancy rates plummeted to as low as 14% for women 40yr or over. The delay prior to conception is also greater in women over 25yr compared to those aged 25-34yr.
The couple:
Greater success after reversal has been reported for couples who have previously had children together before the original vasectomy. In their series, Chan et al found 57% of couples who had previously had a child together achieved a pregnancy compared to 49% where there had been no pregnancy. This phenomenon could be explained by the fact that these couples had already proven fertility together and were ‘biologically compatible’ but other factors, such as (typically) shortened obstructive intervals, or personal reasons such as the death of a child providing additional emotional investment may contribute to improved outcomes in this group.
Intra-operative factors and the question of surgical skill:
The primary aim of the surgeon is to use minimal tissue handling to deliver a tension-free, vascularised and leak-proof anastomosis. Vasectomy reversal has become a highly evolved procedure and the positive impact of increased surgical exposure (numbers) and training in microsurgery has been established. This cannot be a surprise with a vas luminal diameter of 0.3–0.5 mm, and an epididymal tubular diameter of just 0.15–0.2 mm familiarity with microsurgical techniques and instrumentation is crucial. Several studies have shown a correlation between the number of procedures performed annually and reversal outcomes; surgeons performing >15 annually had better patency rates (87%) than those performing <6 operations per year (56%). The location of reversal surgery has not been shown to impact outcomes in appropriately trained surgeons; fellowship-trained, academic, and community urologists performing >10/year had no significant difference in patency rates (79%, 69%, and 71%, respectively). Hands-on training in a laboratory setting improved VV outcomes (89% vs 53%, respectively).
Microsurgical VV as better outcomes than non- enhanced with not only in terms of patency (80% vs 85-90%) and pregnancy rates (20-40% vs. 50-70%) but also the durability of the repair over time, the latter presumably due to reduced anastomotic scarring. Microsurgical VE also yields better results than for macro-surgical anastomoses. However, it should be noted that even in the era of microsurgery that sperm quality reduces to the level of oligospermia or azoospermia within one year following surgery in about 20% of patients who were initially considered successful.
How many layers?:
Debate continues as to whether one, two or three layered anastomoses provide superior results. Both Belker’s Vasovasostomy Study Group and Fischer et al found that one and two-layered anastomoses yielded comparable results. The Belker et al study was, for many surgeons, a game changer although there were weaknesses such as 19% of patients being lost to follow-up. A one-layered technique is quicker, but on occasions may struggle to accommodate discrepancy between lumina. By contrast, the Microdot technique, as described by Goldstein, allows even markedly different lumina to be brought together with excellent results but is technically more challenging. There appears little data to assess whether one or both sides should be reversed, but intuitively it would appear that reversing both sides should not be detrimental.
What of the question of selection of VV or VE at initial surgery?:
There is no doubt that VE is a more complex, technically demanding procedure that occupies more theatre time than VV. In addition, VE has typically higher patency and pregnancy rates than VE and is the preferred option where possible. Operators have used a number of practices to predict the requirement for VE on the first attempt. A number of series correlate obstructive interval wth VE requirement, Parekattil suggesting that an interval as short as 4 years may be a reasonable cut-off period. Many recommend intra-operative microscopic examination and grading of vasal fluid to predict success, with the identification of sperm (or sperm heads) predicting not only higher patency rates with VV compared to those where sperm was absent, but also a faster return of patency; the rationale being that motile sperm in vasal fluid is indicative of a low risk of epididymal obstruction. However, even sperm absence is associated with a VV success rate of 55%, rising to 80% (with a pregnancy rate 38%) where the obstructive interval was under 11 years, leading to the proposition that VV may be reasonable in a carefully selected sub-group of men within intra-operative azoospermia. Visual intra-operative grading has also been found to be of value, with better outcomes associated with a clear, watery transparent efflux better than those with thick, creamy, cloudy fluid. The combination of a long obstructive interval, thick toothpaste-like efflux and absence of sperm on microscopy is par excellence, associated with epididymal obstruction and is a strong negative predictor.
Sperm Granuloma:
The presence of a sperm granuloma at time of surgery is a significant, positive predictor of success with 95% patency rates, compared to 78% without and is strongly predictive that VE can be avoided as the result for VV are so good. It has been suggested that the granuloma area acts as a pressure-release valve and prevents build up of pressure within the epididymis. The presence of a varicocele is not in itself predictive of outcome, but care should be taken if ligation is attempted at the same time, with some suggesting completion of the reversal 6 months prior to subsequent ligation (3). The use of additional supporting tension-relieving sutures are intuitive, but have not been proven.
Recent Comments