In some types of azoospermia in which no sperm is found in the ejaculate or vasectomized patients, there are ways to retrieve sperm for use in an IVF cycle. These techniques can be performed at two levels as indicated by the physician.
Mesa: This is a microsurgical aspiration of fluid from the epididymis.
Pesa: Easier Technique consisting of a percutaneous aspiration of the liquid found in the epididymis
At testicular level:
Tese: Surgical extraction of testicular tissue from the testes.
Tesa: Percutaneous aspiration of testicular tissue.