Percutaneous epididymal sperm aspiration (PESA) and testicular sperm aspiration (TESA) are procedures which are done in cases of extreme male infertility (together with IVF and ICSI). Men who have very low or zero sperm count in the ejaculate (azoospermia) or sperm that are largely dead (necrozoospermia) or completely immotile (asthenozoospermia) can have children by these methods. The sperm are obtained directly from the testis or from tiny ducts leading from the testis i.e the epididymis before they risk damage from oxidation or from exposure to antisperm antibodies in the epididymis or the vas deferens. It can also be done for men who have undergone vasectomy and does not want to have a vasectomy reversal or has had an unsuccessful vasectomy reversal; in men who has  congenital absence of the vas deferens (common in cystic fibrosis carriers) or otherwise has a blockage of the reproductive tract (obstructive azoospermia). It can also be done in men with insufficient sperm production (non- obstructive azoospermia). The sperm collected by the surgical method can be used for intracytoplasmic sperm injection (ICSI).

TESA/PESA/TESE surgery can be performed under local anaesthesia or a short acting   general anaesthetic (depending upon the choice of the patient). In PESA sperm are aspirated from the epididymis while in TESA the sperm are taken out from the testis. TESE is performed under general anaesthesia and the testicle is surgically opened to extract a larger sample of tissue to gather the sperm. The tissue is minced and searched for sperm to be used with ICSI.

 The Sperm collected are either utilized for ICSI or they are frozen for later use. The chosen sperm retrieval method is generally timed to coincide with the female egg retrieval in the IVF/ICSI cycle.