In vitro fertilization can be performed either in situations where surgery is unlikely to succeed, or as a first option. Males, who have had a vasectomy, undergo sperm collection under local or general anaesthesia from either the epididymis (adjacent to the testicle) or the testicle itself.
Microinjection of a single sperm into oocytes (ICSI) achieves a high fertilization rate (60-70%) and implantation rate of up to 30% on transfer of embryos to the uterus. Sperm collection can be achieved in virtually all men who had been fertile before vasectomy no matter how long after vasectomy.
What is TESA / PESA?
Percutaneous Epididymal Sperm Aspiration (PESA) and Testicular Sperm Aspiration (TESA) are procedures used in the management of obstructive and nonobstructive azoospermia (no sperm in the ejaculate). A fine needle is passed into the tubes leading out of the testicles, or the testicles themselves, to retrieve sperm. The retrieved sperm are injected directly into an egg (ICSI) in a similar fashion to sperm retrieved from the ejaculate. This micromanipulation of a single sperm into an egg is the treatment of choice for couples with severe male factor infertility. As a result of this technique, the first ICSI babies were born in 1994, and since then many healthy babies have followed. Many couples now request vasectomy reversal in the hope of having a child when there are altered personal circumstances. However sperm return following reconstructive surgery occurs in approximately 50% of cases, and in these, pregnancy may not result because of the presence of sperm antibodies. The testes do not usually stop producing sperm, which become “pent-up” in the epididymis, located on the side of the testis, leading to the vas deferens. There may also be a relationship between the interval of time since the vasectomy and pregnancy prospects, with the possibility of lower success rates if the vasectomy was performed eight or more years previously. PESA and TESA offer a simple, quick, cheap and comfortable way of accessing sperm for use in assisted reproductive procedures post vasectomy, without resorting to vasectomy reversal. Until recently there were only a few ways for men with irreversible obstructions to become biological fathers. One way was for the man to undergo a complex open surgical operation on the scrotum using a magnifying microscope to allow for retrieval of sperm from the epididymis adjacent to the testis. The other was for the couple to use donor sperm.
How is TESA / PESA sperm used?
Sperm retrieved are specially prepared and individually injected directly into eggs. Routine ovulation induction, egg collection, IVF/ICSI and embryo transfer are employed. To ensure that the procedure is necessary we will sometimes ask the husband/partner to produce a semen sample on the day of the egg collection. This sample will be specially prepared and may be used for injection of the eggs (ICSI) if sperm are present. If not, we proceed to surgical recovery in the form of PESA or TESA.
What is the success rate of these procedures?
Treatment with IVF/ICSI/PESA carries a success rate similar to routine IVF per treatment cycle. This has been a tremendous advance for men with both obstructive and non-obstructive oligospermia. Prior to the development of these techniques very little help was available for men with these problems.
Who are these procedures most suited to?
To summarize, IVF and ICSI after PESA is of value for:
- Men that have had a vasectomy or failed vasectomy reversal.
- Those born with an absent vas deferens (often carriers of a genetic condition called cystic fibrosis).
- Those with other irreversible obstructions of the genital tract.
- Men with primary testicular problems, with deficient spermatogenesis.
