Many people have heard stories of vasectomy failures. I have had patients tell me their father had a vasectomy and they were conceived nonetheless. How does this happen? What are the vasectomy failure rates? How and why can a vasectomy fail?
There is a process called recanalization, where the two ends of the cut tube can find themselves and reconnect. That is very unusual and occurs well below 1% of cases. What is more likely is that on one or both sides of the vas deferens the wrong tube was cut. In the same area of the vas deferens (the tube that carries sperm), there are veins, arteries, lymphatics, and these structures can be cut by accident.
It is crucial that the doctor sends the specimen to the lab for an analysis by a pathologist to make sure the correct tube was cut. Plus men should always get a post-vasectomy semen analysis to make sure they are ‘shooting blanks’.