If you have a zero sperm count, sperm can be collected directly from epididymis using fine syringe. This is known as Percutaneous Epididymal Sperm Aspiration or PESA. Sperm can also be retrieved from the testicles, a process known as Testicular Sperm Aspiration or TESA. In another procedure called Testicular Sperm Extraction or TESE testicular tissue is removed surgically from which sperm can be extracted.
Intra – cytoplasmic sperm injection (ICSI) differs from conventional in vitro fertilization (IVF) in that the embryologist selects a single sperm to be injected directly into an egg, instead of fertilization taking place in a dish where many sperm cells are placed near an egg.