This technique is recommended for those cases of infertility in which there is a very low concentration of sperm in the male ejaculate. Epididymal sperm aspiration is also recommended for those cases in which there is a complete absence of sperm in the sample (obstructive azoospermia) due to blockage or congenital absence of the vas deferens.
In addition, those men who have previously had a vasectomy, but wish to have children, can also have this procedure performed to obtain sperm.
Whenever sperm aspiration is performed, it must be complemented with ICSI (intracytoplasmic sperm injection) to try to fertilize the eggs.
Suggested for you: What is Epididymal Sperm Aspiration? Procedure & Techniques.