Testicular Sperm Aspiration (TESA) are surgical procedures that may be used to find sperm where the male partner does not have sperm in his ejaculate (also known as azoospermia).
Successful sperm production and delivery relies on a system of tubes located within the male reproductive system. Initial production of sperm occurs in fine, tightly coiled tubes located within the testes, known as seminiferous tubules. The seminiferous tubules are connected to a long, coiled tube called the epididymis. The epididymis is in turn connected to another tube called the vas deferens. In order to produce ejaculate containing sperm a male must first produce sperm in the seminiferous tubules, these sperm must then move through the epididymis then on to the vas deferens in order to be deposited in the semen during ejaculation.
Where azoospermia is caused by an abnormality or obstruction of the epididymis or vas deferens it is referred to as obstructive azoospermia. In these cases it is assumed that sperm are being produced but are prevented from being deposited in the ejaculate due to an obstruction. Examples of causes of obstructive azoospermia include undergoing vasectomy or a congenital absence of the vas deferens (common in male carriers of cystic fibrosis).
Azoospermia may also be the result of insufficient sperm production, or occasionally a complete lack of sperm production. These cases are referred to as non-obstructive azoospermia.
TESA involves passing a fine needle directly into the testes in order to retrieve a small number of the seminiferous tubules. In most cases sperm can be isolated from the seminiferous tubules after preparation by the laboratory. Both of these surgical procedures can be performed under local anaesthetic or sedation, depending on the preference of the patient and the clinician.