Vasectomy Research
VASECTOMY METHODS
VASECTOMY OCCLUSION: WHICH IS THE BEST TECHNIQUE?
The highly esteemed Cochrane group aimed to ‘compare the effectiveness, safety, acceptability and costs of vasectomy techniques for male sterilization.‘
Let’s translate the question as simply ‘which is the best way to perform vasectomy?’
The Cochrane group ‘research the research’ and conclude ‘For vas occlusion with clips or vasectomy with vas irrigation, no conclusions can be made as those studies were of low quality and underpowered. Fascial interposition reduced vasectomy failure.’
COMMENTS
Many leading vasectomists in The US, Canada and Australia practice Fascial Interposition (FI). The research tentatively points to a lower failure rate of vasectomy after FI.
Is Open-Ended Vasectomy Truly Open?
Does the tube remain open after an Open-Ended Vasectomy?
Open-Ended Vasectomy is considered by many vasectomy experts to be superior to closed vasectomy. Open-Ended Vasectomy involves cutting the tube & leaving the lower end alone (no cautery or closure to the lower end). The open tube allows for drainage of sperm away from the testicle which is thought to reduce the risk of back-pressure that might cause swelling or pain.
But does the tube actually stay open after an Open-Ended Vasectomy?
You can’t randomly biopsy men a few weeks after their vasectomy. Rats, however, have a very similar Tube (Vas Deferens) to humans.
A study was performed in rats that underwent either an open or a closed vasectomy. The tubes were examined microscopically some weeks later.
Surprisingly, 2 out of 5 rats that had an Open-Ended Vasectomy revealed obstruction of the tube by a ‘fibromuscular cap.’
The study concluded that ‘by 8 weeks after surgery both vasectomy procedures are equally effective in preventing further damage in the epididymis caused by elevated intraluminal pressures.’
COMMENT
Open-Ended Vasectomy is considered to reduce back-pressure caused by sudden blockage of the tube that drains the testicle of sperm. In all likelihood, the tubes will close over several weeks.
Closed Vasectomy will immediately close the tube draining the testicle, whereas any closure after Open-Ended Vasectomy is expected to be gradual.
A COMPARISON OF METHODS OF PERFORMING VASECTOMY – WITH OR WITHOUT CAUTERY?
A comparison of vas occlusion techniques: cautery more effective than ligation and excision with fascial interposition was published in 2004.
Men in the study had one of two methods of Vasectomy Occlusion:
- Cautery of the Tubes (Intraluminal Cautery), or
- Without Cautery (the tubes were cut & tied) – with or without fascial interposition.
Vasectomy with Cautery had fewer failures (1% versus 5%).
Results: Vasectomy with cautery was associated with a significantly more rapid progression to
severe oligozoospermia and with significantly fewer early failures (1% versus 5%).
COMMENTS
This study suggests that methods of blocking the tube that do not involve Cautery may be risky. Cautery used ‘on its own’ is common in The UK. Cautery used alongside Fascial Interposition is common The US & Australia.
As always with research like this, the devil is in the detail & there may well be successful vasectomists who do not utilise cautery.
EFFECTIVENESS OF VASECTOMY USING CAUTERY
Effectiveness of vasectomy using cautery was published in 2004. This study researched the effectiveness of vasectomy following different methods of occlusion. All 4 methods of occlusion included Cautery of the lumen of the tube.
378 men were included in the study. The overall failure rate was 0.8%.
However, it was not possible to conclude which method is ‘best,’ with the investigators stating that that ‘Our study was not designed to analyze the efficacy of the various occlusion procedures used at the study sites, but rather to estimate effectiveness of occlusion techniques that include use of cautery.’
COMMENT
We don’t know from this study which method of occlusion is ‘best’ but simply that the overall failure rate is around 1 failure in 120 Vasectomies, and emphasizes the need for the post-vasectomy sample.
SAFETY & SIDE EFFECTS
POST VASECTOMY PAIN
Post Vasectomy Pain Syndrome (PVPS) is defined as pain occurring for at least 3 months after a vasectomy. The PVPS definition requires that the pain is at a high enough level to interfere with quality of life, and that non-vasectomy causes for discomfort or pain have been excluded.
A 2020 paper entitle ‘Incidence of Post-Vasectomy Pain: Systematic Review and Meta-Analysis’ aimed to find out how often post vasectomy pain occurs. This ‘study of studies’ identified 18 separate studies for analysis. ‘The primary outcome measure was the incidence of post-vasectomy pain, presenting two weeks or later after the procedure.’
‘The overall incidence of post-vasectomy pain across all studies was 15% with a higher incidence of 24% for traditional scalpel vasectomy compared to 7% for NSV.’
In other words, the study found that 7% of men reported pain at least 2 weeks after a no-scalpel vasectomy.
COMMENT
The study looked at post vasectomy pain at least 2 weeks after the vasectomy, and not post vasectomy pain syndrome which requires pain to last at least 3 months.
Around 7% of men have discomfort 2 weeks after a no-scalpel vasectomy.
LONG TERM SAFETY OF VASECTOMY
Long-term safety, health and mental status in men with vasectomy was published in October 2018.
No-Scalpel vasectomy was pioneered in China where this study was performed. 485 men with the vasectomy were recruited into the study along with 1940 men who did not undergo vasectomy. The 2 groups were compared for men’s health symptoms, hormone levels, and psychological symptoms.
Of note:
- Vasectomy had no long-term effect on the level of sex hormones, namely testosterone & free testosterone.
- Vasectomy did not increase The PSA (Prostate cancer screening blood test).
COMMENTS
The authors of the study state that ‘results showed that middle-aged and older people are mainly infuenced at the psychological level rather than the physiological level afer vasectomy.’
The study confirms what we already know – that there are no hormonal or biochemical effects following Vasectomy.
MORTALITY AFTER VASECTOMY
There has been one recorded death caused by Vasectomy.
A 32 year old male without any significant medical history had an uneventful vasectomy performed in The Netherlands. He presented 2 days after the vasectomy with a fever and was admitted to hospital. Blood tests showed a high white cell count. Surgery was performed to remove blood and infective tissue from the scrotum. He died of an overwhelming infection 5 days after the vasectomy.
COMMENTS
Hundreds of millions of vasectomies and one recorded death confirms that vasectomy is an exceptionally safe surgical procedure. The man sadly died of Fournier’s gangrene which is a very rare complication of Vasectomy.
Fourier’s gangrene is a very rare serious infection of the scrotum that may be triggered by any surgical procedure of the scrotum – including vasectomy. The most common risk factors are poorly controlled Diabetes, and Immunosupression. The condition is extremely uncommon.
VASECTOMY & PROSTATE CANCER
This vasectomy research review blog concentrates on studies published recently. Numerous older studies attest to the safety of vasectomy and prostate cancer. Remember that recent studies does not necessarily equate to better studies.
2021 metaanalysis:
A 2021 analysis by Chinese researchers in the journal ‘prostate cancer and prostatic diseases’ concluded that ‘vasectomy was associated with the risk of any, localized, low-grade and intermediate-grade prostate cancer. Meanwhile, vasectomy was not associated with prostate cancer-specific mortality.’
The study was not an original study, but rather a ‘study of studies’ called a meta analysis. 58 out of 103 studies were deemed suitable for inclusion. The analysis reported that prostate cancer was increased by 18% in those who have had a vasectomy, but that the risk of dying from prostate cancer was not increased.
COMMENTS
The statistical tools used in this analysis are complex: the Higgins I statistic, Mantel-Haenszel method, DerSimonian and Laird methods, with use of Egers’s test and followed by the Seta SE meta-analysis, tools which were used to identify 56% of studies as suitable for the actual analysis. You need to be a statistician to make sense of all this.
The original studies were population studies are designed to look for association – in other words, condition A is more common with risk factor B.
A reasonable hypothesis is that men who have had a vasectomy are more likely to go to a doctor for a men’s health check than men who have not had a vasectomy. Prostate cancer is very commonly diagnosed following a blood test performed as part of a general health check. Recent studies have tended to show an association with prostate cancer whilst older studies have not.
Most of the studies analysed in this study were published prior to the last revision of The AUA vasectomy guidelines that indicated that vasectomy is not a cause of prostate cancer.
An individual study that did suggest a link is now discussed, but many studies in the past have found no link.
A 2020 Danish population study:
Vasectomy and prostate cancer risk: a 38-year nationwide cohort study.
A Danish study looked at a group of Danish men ‘from The National Health Insurance Service Registry.’ The database of over 2 million men included 26,238 cases of Prostate cancer.
- Men who had a Vasectomy ‘had an increased risk of prostate cancer compared with non-vasectomized men.’
- Men who had a Vasectomy had a ‘diminished relative risk of all other cancers.’
COMMENTS
All studies that are ‘observational’ need to be treated with caution. The researchers did take account of ‘potential known confounding factors’ but it’s almost impossible to truly take account of all confounding factors.
Numerous other studies have found no increased risk of Prostate cancer following a vasectomy.
The American Urology Association vasectomy guideline is made up of a panel of over 50 experts. The guideline is updated every few years, and the most recent 2015 guideline does not find that vasectomy and prostate cancer are associated.
FAINTING AFTER BLOOD DONATION
How common is fainting during or shortly after vasectomy?
There is no published data on the incidence of fainting during or after Vasectomy. However, there is research that looked at fainting after blood donation.
Overall, 1.23% of people donating blood had a faint. Women were 2.9 times more likely to faint than men during their donation.
COMMENT
Loss of consciousness during vasectomy performed in our clinic is very rare. Surprisingly, 1 in 70 individuals donating blood are reported to faint.
MISC.
MEN’S ATTITUDES TO VASECTOMY
397 men age 25-70 living in The Southern USA were recruited via facebook advertisement to complete an online survey in a study published in 2020.
The authors concluded that ‘Participants who had not had a vasectomy had less positive attitudes about the procedure across all six attitude subscales compared to participants with vasectomies.’
The authors discuss possible reasons why men who have had a vasectomy are more positive about vasectomy than men who have not had a vasectomy:
- ‘Men might believe that vasectomy causes them to lose their libido; however, research has identified that vasectomy can have positive effects on sexual satisfact.
- ‘Attitudes about the procedure and recovery may be driven by beliefs that vasectomy is invasive, painful, or debilitating. Yet, the majority of vasectomies are minimally invasive outpatient procedures requiring only local anesthesia that take approximately 15 min.’
- ‘Research has demonstrated that men who had a vasectomy found it significantly less painful than they anticipated.’
COMMENTS
Humans are all prone to ‘confirmation bias’ – we tend to justify our beliefs and preconceptions.
The study was a simple ‘one point in time’ (cross sectional) study and not designed to determine association .v. causation. Association simply implies that men who have a positive attitude about vasectomy are more likely to have one. On the other hand, causation would imply that men who have a vasectomy are more positive because of the experience. Either way, guys who have had a vasectomy are usually positive about it, and men who have not had a vasectomy are less positive about it!
NO NEEDLE VASECTOMY
Introduction to The Madajet
The Madajet is used in North America and Canada for No Needle Vasectomy. The device is not approved by The TGA for use in Australia.
The No Needle device is a specialised instrument that sprays rather than injects local anaesthetic through the skin.
The instrument has a specific fitting that is designed to be used only for No-Scalpel Vasectomy. The fitting is a curved shape that is designed to gently sit on top of the tube before releasing the anaesthetic.
The high tech mechanical device works by spraying local anaesthetic through the skin to the underlying tube. The objective is to numb both the skin and the underlying tube. This is performed with meticulous attention to detail.
Guys report the following with the no needle anaesthesia device:
- ‘That’s different’ (laugh)
- ‘like a a flick’
- like an elastic band snap
The jury is really out as to whether the experience of a no needle anaesthesia is superior to that of invisible needle anaesthesia.
What does the research say?
Their conclusion is that ‘for local anesthesia in patients undergoing surgical sperm retrieval, MadaJet produces less pain and discomfort with quicker time to onset and offset of anesthesia compared with conventional needle injection.’
OFFSPRING SEX RATIO AND VASECTOMY!
The study looked at a large health database from the USA.
30,927 men underwent Vasectomy. They reported that ‘For men with at least 2 children, each additional son increased the likelihood of vasectomy by 4%, whereas each additional daughter led to a 2% decrease in vasectomy utilization.’
In other words, fathers undergoing vasectomy have a higher proportion of sons compared with fathers who have not had a vasectomy.
COMMENT
A quirky & somewhat controversial study! Men with sons are more likely to say ‘enough is enough’ – and to get a Vasectomy – than men with daughters!
ROUTINE USE OF STRONG PAINKILLERS AFTER VASECTOMY
Routine use of opioids after vasectomy was published in The Journal of Urology in 2019.
This paper attempted to answer the question as to whether strong painkillers need to be described regularly after vasectomy. Vasectomists have in the past prescribed strong painkillers routinely after vasectomy – for example panadeine forte, Endone or tramadol.
102 patients received a prescription for strong painkillers for use after their vasectomy and 126 received no prescription. The results were:
- There was no difference between the two groups in the experience of scrotal pain following the vasectomy
- Men who received a prescription for strong painkillers were more likely to get addicted to them afterwards.
A further American study published in 2020 concludes that ‘Patients that are not prescribed opioids after vasectomy do not generate additional phone calls, clinic or
ED visits compared to those that were routinely prescribed prior to our institutional change. We have permanently discontinued the routine use of opioids for post-vasectomy analgesia. Other physicians performing vasectomy should consider making this change as well.’
COMMENTS
Prescriptions for strong painkillers are simply not required after vasectomy. There is an epidemic of people who are addicted to prescribed opiates in The US where these studies were performed. There is no place for routine prescribing of strong painkillers after a vasectomy because single script has the potential to convert a ‘patient’ into a long term addict.
USE OF CONTRACEPTION BEFORE THE ‘ALL CLEAR’
Vasectomy should not be considered a reliable form of contraception until the post-vasectomy sample confirms that the vasectomy has worked.
Use of secondary contraception following vasectomy: insights from the Pregnancy Risk Assessment Monitoring System, was an American study that investigated the use of contraception in the period between the Vasectomy and the post-vasectomy test.
1004 couples were investigated who:
- Had recently had a baby, and
- The male partner had a vasectomy after the baby was born
An astonishing 57.8% of couples reported NOT using additional contraception after the vasectomy (before the post vasectomy sample). The 43% of couples who DID use additional contraception mainly used condoms (50%).
COMMENTS
This study looked at couples who had a vasectomy after having a baby. Mothers who breastfeed and have no periods are unlikely to conceive. The couples may not have used contraception because they believed that breast feeding is a good form of contraception. Nevertheless, there is concern that over half of couples in this study did not use contraception in between the vasectomy and the post vasectomy test.
Vasectomy providers emphasise that Vasectomy is only reliable after the confirmatory post vasectomy test.
CONTRACEPTION USE IN COUPLES BEFORE UNINTENDED PREGNANCY
The goal of contraception is to effectively prevent pregnancy. However, all forms of contraception can fail, particularly condoms and the pill. Vasectomy is least likely to fail.
Which type of contraception, if any, is used before an unintended pregnancy?
326 Australian women were interviewed about unexpected pregnancy in a 2018 study.
Just 41% were using contraception at the time of the pregnancy, and of these:
- 64% were using the contraceptive pill
- 27% of couples were using condoms
- 9% were using ‘the rod’ (hormonal device that is inserted in the upper arm)
POSTAL .V. FRESH POST VASECTOMY SAMPLE
The 12-14 week Post vasectomy testing requires a ‘fresh sample’ in most countries, but also available as a postal sample in The USA and The UK. The fresh sample requires taking the sample to the local laboratory for analysis of sperm concentration and motility (movement) within 2 hrs, whereas the postal sample simply requires dropping the sample into your local post box to test for zero sperm a few days later.
How does the postal sample perform against the gold standard fresh semen analysis?
This study analysed data from 58,800 vasectomies performed in The UK over 11 years. The postal method was used in 59% of vasectomies, and the fresh sample in 44% of vasectomies.
They found that ‘Compliance with postal (79.5%) was significantly greater than with non-postal strategy (59.1%), the difference being 20.4%.’
There was no significant difference in the rate of failure between postal and fresh samples.
COMMENTS
This research informs us that 20% more men offered the postal test, compared with men required to do a fresh sample, will do a post vasectomy test. The postal test is more than convenient – it can make the difference between doing the test and not doing the test.
It’s worth noting, however, that postal samples are more likely to require a further test than an initial fresh sample, and that a further test would require a fresh sample – somewhat offsetting the convenience of an initial postal sample. The reason is that the postal sample needs to be entirely clear of sperm, whereas a few non-motile sperm in the fresh sample allows for clearance from the one sample.
Perhaps the most interesting observation is the relatively high failure rate in this UK study where closed vasectomy is standard. Whilst the failure rates of 0.94% and 0.73% did not differ significantly between the two groups, these failure rates are high compared with < 0.3% failure rate of open-ended vasectomy. Many vasectomists practicing open-ended vasectomy will achieve a failure rate of < 0.2% (1 in 500).