Fundamentally, what a vasectomy does is to prevent the flow of sperm from the testicle to the urethra by cutting and blocking off the ends of the vas deferens, the tube which carries the vasal fluid. There are many ways to block off the vas deferens.
Suture is very common, where a thread is tied around the end of the vas to prevent the flow of sperm.
Cauterization is also a common method, using heat to create scar tissue that will block the flow of sperm.
Another very common method is the use of metal clips, which clip off the ends and are embedded in the scar of the vasectomy site.
It’s not uncommon to have a small portion of the vas removed as well- up to an inch.
Dr. Shu uses 3 steps to insure complete occlusion: he cuts the vas deferens and destroys the lining of the tube on upper end with cautery (scarring it) and places small titanium clips in the vas fascia to separate the opened ends of vas deferens.
No-scalpel vasectomy is performed by making the tiny opening in the middle of scrotum with a pointy hemostat. The vas is then pulled out, severed, and blocked off.
Another method is open-ended vasectomy, where the vas end closer to the testicle is left open instead of being blocked off in order to reduce the post vasectomy. It also save more vas to make a reversal easier.
Vas crimping with VasClip or Pro-Vas was not favorable because of the high failure rate. These still require surgery for a vasectomy reversal, so the idea of crimping rather than severing is a moot point.
Ultimately, none of these ways seem to affect the chances of a reversal being successful. The type of vasectomy, how it was blocked off, how the incision was made, etc, will not actually have an effect on the success rate of the reversal.
What really makes a difference when it comes to success of the reversal is time (years after vasectomy). Time is the single most important factor. Each year after vasectomy patency gets lower.
There are two metrics when looking at success rate: sperm patency and pregnancy rate. Sperm patency has to do with the motility of the sperm, that is, how much sperm is present and how much of the sperm in the semen is moving and healthy. The pregnancy rate is typically lower, since not everyone chooses to have a child after a reversal, and sometimes there can be issues on the woman’s end, or there is simply not enough motile sperm.