If too few healthy sperm cells are available, or if the semen results show that the sperm is of low quality, a TESA (testicular sperm aspiration) or TESE (testicular sperm extraction) can be taken into consideration. In the case of blocked vas deferens or of a congenital bilateral absence of the vas deferens, or if no sperms are found in the ejaculate, the semen can be extracted from the testicles or epididymis by means of a small surgical procedure.
The TESE is a technique in the course of which a small bit of testicular tissue is removed in a surgical procedure, extracting sperms which can then be used for an ICSI.
This technique is applied if we get the following results:
The TESA (testicular sperm aspiration) is a technique that is less invasive than the TESE and can for instance be applied when the spermatic ducts are blocked.
The subsequent preparation in the embryology laboratory serves to sort out sperm cells of a poor quality. The healthy sperm cells pass through the crucial maturation process and can therefore be fertilised.