Percutaneous Epididymal Sperm Aspiration (PESA) and 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.
PESA involves passing a fine needle into the epididymis (the tubes leading out from the part of the testes where the seminiferous tubules are located) to obtain sperm. 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.
Sperm retrieved using PESA/TESA can be used to attempt to achieve a pregnancy using an assisted reproduction technique called intracytoplasmic sperm injection (ICSI). In order to perform ICSI the female partner will need to undergo routine ovulation induction and egg collection (egg collection is usually performed on the same day as the PESA/TESA). Sperm that has been isolated during a PESA/TESA can then be injected into the eggs collected from the female partner.