Percutaneous Epididymal Sperm Aspiration (PESA) / Testicular Sperm Aspiration (TESA)

The injection of a single sperm directly into the centre of an egg (ICSI) has now become the treatment of choice for couples with a severe male infertility factor. Fertilisation is prevented because poor sperm lack the progressive motility required to break through the outer membrane of the egg (zona pellucida). The same technology (ICSI) may be used with sperm recovered from those with men who have no sperm in the ejaculate (azoospermia).

Until recently, the only way for men with irreversible obstructions to become biological fathers (rather than the couple considering the potential use of donor sperm) was for the man to undergo a complex open surgical operation on the scrotum, preferably using a magnifying microscope to allow for retrieval of sperm from the epididymal tubules located adjacent to the testis. The operation is known as MicroEpididymal Sperm Aspiration (or MESA for short).

PESA- A simple system of recovering sperm passing a needle into the epididymis through the skin. This is performed under sedation, or general anaesthesia on a day patient basis. Sperm retrieved are specially prepared and then individually injected directly into eggs recovered for ICSI. This needle aspiration technique is caled "PESA" (Percutaneous Epididymal Sperm Aspiration).

PESA has many advantages and is much more acceptable to patients who usually return to work the next day and generally have no anxiety about its repetition if this is required.

The pregnancy rates from the application of the PESA procedure with the ICSI technique in couples with obstructive azoospermia are mainly affected by:

• the age of the woman producing the eggs,
• the number of mature eggs available for microinjection,
• the number of embryos transferred.

In summary, IVF and ICSI after PESA is of value for:

• men with failed vasectomy reversal,
• those born with an absent deferens, and
• those with other irreversible obstructions of the genital tract.

Testicular Sperm Aspiration (TESA)

There is a different category of patients who do not have any sperm in the semen (azoospermia). These men do not have an obstruction in the vas, but rather a degree of testicular failure. The testes might still produce some sperm but they may be in an insufficient number and do not appear in the semen. They however may still be recovered from the testes.

The previous way of recovering testicular tissue was by an open surgical operation through a scrotal incision and then taking a biopsy of testicular tissue. In addition to the potential complications which include post operative pain, bleeding and infection, this technique was associated with some irreversible loss of testicular tissue. It might also lead to damage of the blood supply to the testes and as a consequence loss of living tissue.

TESA is a simple procedure and there is less risk of complications compared to an open surgical operation. Patients usually return to work the following morning after the procedure. It is carried out as an outpatient procedure under intravenous sedation, local anaesthesia or a combination of both. The procedure does not take long. Because some patients have 'islands' of sperm producing tissue within the substance of the testicle, the TESA technique is more likely to pick up such 'islands' of tissue compared to the older technique of open testicular biopsy.

TESA is also indicated in the few patients with obstructive azoospermia in whom PESA has not been successful due to damage or scarring of the epididymis or defective sperm production in the testes which can also be associated with an obstruction.

We sometimes recommend performing a diagnostic PESA/TESA procedure at least 3 months before the planned IVF/ICSI treatment cycle. If motile sperm are recovered, either from the epididymis or testes, the sample may be frozen in small tubes, or straws, for several treatment cycles. This saves patients the need for a repeat procedure.

When IVF and ICSI treatment is planned we prefer to book the patient for a "back up" procedure on the day of their wife's egg collection, in case the frozen sperm/tissue does not survive the thawing process after having been frozen which happens occasionally.

Also Read:
Ovulation Induction
Intra-Utreine Insemination (IUI)
In-vitro Fertilization ( IVF/ Test tube baby)
Intra-cytoplasmic Sperm Aspiration ( ICSI)
Percutaneous Epididymal Sperm Aspiration (PESA) / Testicular Sperm Aspiration (TESA)
Egg Donation / Sperm Donation/ Embryo Donation
Frozen Embryo Transfer