Sperm can be retrieved directly from the testis rather than from the ejaculate. These procedures are often called TESA (testicular sperm aspiration), TESE (testicular sperm extraction) or PESA (percutaneous epididymal sperm aspiration) or Micro-TESE.
Why would surgical sperm recovery be performed?
The most common reason is because sperm are not present in the ejaculate. This can be because the vas deferens (the tube which carries sperm from the testis) can be blocked due to a vasectomy or if the man is a carrier of the genes for cystic fibrosis. Sometimes the sperm are present in the testis in very low quantities and are not seen in the ejaculate.
How is the sperm extracted?
There are two ways in which sperm can be extracted. If the sperm is blocked, there are generally abundant in the testis and can be extracted by passing a fine needle into part of the testis (the epididymis at the top of the testis) or the testis itself. These procedures are performed under local anaesthetic.
Sometimes sperm are produced in very low amounts in the testis and cannot be ejaculated. In these cases a technique called micro-TESE can be performed. This is performed under general anaesthetic by a surgeon (usually a urologist) using an operating microscope. A scientist takes samples and seeks live sperm in the samples removed from the testis. This is highly skilled work which takes a long time.
How are the sperm used?
Sperm obtained through TESE and micro-TESE can be used directly if there’re fresh or frozen oocytes (eggs) available or sperm can be frozen. Fertilization of the eggs is by injecting the sperm directly in the eggs in a procedure called intracytoplasmic sperm injection (ICSI).
Are there any risks?
These procedures can be painful. Rarely bleeding may occur and long-term damage to the testis causing hormone deficiency may occur. Men who have reduced testicular production of sperm are at risk of developing hormonal deficiency.