This surgical procedure is indicated in cases of congenital absence of the vas deferens (the long tube through which sperm travel during ejaculation), although some males with a vasectomy or failed vasovasotomy are also candidates. This technique allows aspiration of sperm from the epididymis, a tubular structure attached to testicle that serves as a reservoir where sperm mature and are stored. Because very low numbers of sperm are obtained, it is in conjunction with intracytoplasmic sperm injection.
PESA is indicated for men with irreparable obstruction resulting in Azoospermia (lack of or no sperm), congenital absence of the deferens or who have had vasectomies or failed vasectomy reversals. The procedure takes approximately 10 to 20 minutes and unlike epididymal aspiration, does not require a surgical incision. A small needle is passed directly into the head of the epididymis and fluid is aspirated. Next, the IVF laboratory team retrieves the cells from the fluid and prepares them for ICSI.
This involves surgical removal of a portion of the testes for patients that are poor candidates for PESA because of absence of the vas deferens. In the andrology laboratory, tissue is homogenized (minced) and individual sperm is harvested for ICSI.
Microsurgical fertilization, a form of micromanipulation, is indicated in case of severe male factor, where conditions such as abnormal sperm movement or low sperm numbers make it impossible for sperm to penetrate and fertilize the egg. One of the methods to assist fertilization is Intracytoplasmic Sperm Injection (ICSI). ICSI involves the use of very fine instruments to first pick up sperm and then inject a single sperm directly into the cytoplasm of the egg. The cytoplasm is the area outside the nucleus of the oocyte and contains the physical elements of reproduction. ICSI also works for cases of unexplained non-fertilization with conventional IVF.