Testicular sperm aspiration (TESA) is a procedure performed for men who need to have sperm retrieved for IVF/ICSI procedures. A needle is inserted in the testicle and tissue/sperm is aspirated. TESA is performed for men with obstructive azoospermia (for example vasectomy). Occasionally, TESA does not provide enough tissue/sperm and an open testis biopsy is needed.