Patients on Aspirin or other blood thinning medications requiring Vasectomy

Image of an Aspirin tablet dissolving in a glass

A blood thinning aspirin tablet

Aspirin, blood thinning medicines and vasectomy…

Blood thinning medications including Aspirin and vasectomy is a common issue raised by patients.  Patients are on blood thinners for a variety of reasons and in many cases it may not be safe to stop them. Find below some answers to your questions.

Which blood thinning medications will this article cover?

The principles discussed in this article are true for all blood thinning medications, but there are specific issues that will be discussed in specific sections. Apart from Aspirin the article will cover Clopidogrel, Dabigatran, Apixaban, Rivaroxaban, Warfarin and others. Even if your personal blood thinning medication is not mentioned it is worth reading on.


What does Aspirin do?

Aspirin is a blood thinning medication that avoids blood clotting by irreversibly inhibiting platelet aggregation in your blood. Platelet half time in your blood is 5 days. Thus, after 10 days still roughly 25% of your platelets cannot aggregate. You can see, how long it takes for the effects of Aspirin to reduce its effect.

Benefits of Aspirin:

Secondary Prevention: By reducing the ability of your blood to clot you can improve circulation in areas that are poorly circulated, for example after heart surgery a stroke or a heart attack. Thus, you take it, because a health event has already occured.

Primary Prevention: However, there are also people that take Aspirin for Primary prevention (no previous problems, but a choice) for example 50-70 year olds according to the recommendation of the US FDA as Aspirin is an effective cancer preventer.

What else can I do to avoid clotting:

Thick blood clots quicker than thin blood, so for example being well hydrated is a good way of avoiding more blood clotting than necessary and I would recommend anyone choosing to stop Aspirin before Minor surgery that they always ensure to be well hydrated while Aspirin is stopped.

Is Vasectomy Minor Surgery?

Yes and No. While the procedure is definitely Minor Surgery the side effects of a bleed are significantly more pronounced because the “skin turgor” of the scrotum is almost nil. This means the skin isn’t pressing on the wound to stop bleeding like for example on the arm or leg. Thus, a scrotum can more easily fill up with blood and takes longer to absorb. Aspirin and vasectomy is definitely a specific issue.

Should I stop Aspirin before surgery? And when should I re-start?

In Major Surgery Aspirin is generally stopped before surgery and replaced with Heparin. In Minor Surgery and vasectomy it depends as there is a balance to be struck between the bleeding risk and the risk to your safety.

Its probably not good to stop Aspirin if you are taking it for secondary prevention (i.e. due to a previous problem with your heart or brain). If you however take it for Primary Prevention you should strongly consider to stop Aspirin.

If you choose to stop Aspirin it doesnt make sense to stop the day before as it wont work, you have to stop at least 10-14 days prior to the procedure and also not re-start while bleeding risk is increased i.e. a week after the procedure.

How about Dual Therapy (taking 2 blood thinners at the same time)

If you are on 2 blood thinners at the same time you should not get a vasectomy in the community. You usually only take 2 blood thinners i.e. Aspirin and Clopidogrel for a year i.e. after a stroke. Wait until your consultant reduces you down to one blood thinner (which you will be on for life). Then come and see us.

What if I am on other blood thinners i.e. Warfarin, Rivaroxaban, Apixaban or Dagibatran?

Most of these blood thinners are important to avoid repeated blood clots and should not be stopped unless a medical specialist advises you to do so. However, as all patients on blood thinners are at a higher risk of bleeding, bruising and side effects some patients choose to stop these medications anyhow. If you stop them you have a lesser chance of bleeding, but a higher chance of clotting. Please read below for top tips when stopping a blood thinning medication before surgery or any other procedure (vasectomy, dental procedures etc).

How high is my risk of clotting if I choose to stop Aspirin?

It is very important to be statistically savvy. Aspirin reduces the chance of blood clotting, it doesnt mean it stops you clotting. You can still clot while on Aspirin, but there is generally a 30% risk reduction. I.e. if 3 out of 100 patients would have a blood clot without Aspirin there would then be only 2 out of 100 patients having a blood clot once they take Aspirin.

In other words: Most patients stopping Aspirin will not get a blood clot, but run a slightly higher risk, but equally even if you are on Aspirin you still could get a blood clot.

If I have a procedure on Aspirin or another blood thinner, will I definitely bleed?

No. Most patients are absolutely fine, but occasionally we have had patients with longer stays and more problems. Statistically, your risk is higher, but that doesn’t mean you will have problems.

What should I do next?

For me as a doctor, it is very important for you as a patient to be well informed. Thats why I have written the above article. Based on this information we can then make a shared decision balancing risks vs benefit of stopping. In the end your decision is final. All I am asking you is that you consider the issues around blood thinning medications and Vasectomy. if you choose to stop Aspirin or any other blood thinners ensure your hydration levels are adequate throughout the time. If you choose to continue on blood thinnning medicines I want you to not worry about it as we doing everything in our power to make your experience as good as anyone elses.

Top tips for patients choosing to stop blood thinning medications.

  • Dont stop if your underlying diagnosis is very serious (i.e. stroke). If you take them for a less problematic diagnosis i.e. an irregular heart beat, then the balance can occasionally lean more towards stopping.
  • Speak to your doctor before stopping and ask them what they would do.
  • If you decide to stop, make sure you are staying well hydrated and do not get dehydrated.
  • Aspirin has a very long half life. No point stopping a day or 2 before. The half life is 5 days, so after 10 days you still have 25% of the power of Aspirin left in your blood.
  • Clopidogrel, Rivaroxaban, Apixaban and Dagibatran have all short half lifes. You can stop them a couple of days before and thats fine.
  • if you start too early after the procedure you could still bleed.
  • Warfarin has a long half life and is also difficult to titrate up again. But if you normally on an INR level (Warfarin level) of 2-3 then perhaps consider going down to a level between 1.8 and 2.2 before vasectomy to reduce your chance of bleeding.

Dr Kittel, March 2023

For information about Aspirin in Minor Surgery click here (very similar article, though)