Testicular biopsy and aspiration refers to specialized sperm-extraction techniques for the treatment of severe cases of male-factor infertility.
TESA can be used as a diagnostic procedure to detect causes of male infertility, or as a procedure to recover sperm from the testicles from men with obstructions or ejaculatory problems that cannot be treated by any other methods.
In the TESA procedure, a very fine needle is passed into the testicles under anaesthetic, and a tiny amount of tubules is removed from the seminiferous tubules (network of tiny tubes inside the testicles, where sperm are produced). These tubules are then processed in the laboratory and checked for the presence of sperm, which can be used to fertilize eggs.
Sperm retrieved from the seminiferous tubules in a TESA procedure are less mature and less motile than sperm found in ejaculated seminal fluid. As such, ICSI or IMSI are required to achieve fertilization with TESA sperm.