PESA
PESA or Percutaneous Epididymal Sperm Aspiration (PESA), does not require a surgical incision. This is a technique whereby, under general or local anaesthetic, a needle is inserted directly into the head of the epididymis through the scrotal skin and fluid is aspirated. The embryologist then retrieves the sperm cells from the fluid and prepares them for ICSI.
MESA
Microsurgical Epididymal Sperm Aspiration (MESA) is used in conditions like obstructive azoospermia. The technique involves dissection of the epididymis under the operating microscope and incision of a single tubule. The fluid that spills from the Epididymal tubule and pools in the Epididymal bed is then aspirated. This technique is compromised by the fact that the aspirated fluid invariably is contaminated by blood cells that may affect sperm fertilizing capacity in vitro.
TESA and TESE
TESE or testicular sperm extraction is a surgical biopsy of the testis in which a small portion of the testicle is removed and examined subsequently to extract any sperm from it.whereas TESA or testicular sperm aspiration is performed by inserting a needle in the testis and aspirating fluid and tissue with generation of a suction pressure. The aspirated tissue is then processed in the embryology laboratory and the sperm cells extracted are used for ICSI.