These are the procedure for surgical retrieval of sperms from testis where there is nil sperm count.
PESA is per cutaneous epidydimis sperm aspiration.This procedure is used where is there is an obstruction of vas deferens i.e. sperm is produced in testis but its not present in semen due to outflow tract obstruction. In this procedure a needle is introduced though epididymis and sperm is retrieved from epidydimal fluid.The retrieved sperm is then fertilized with egg with the help of ICSI.
TESA is testicular sperm extraction.In this the needle is introduced inside the testis to retrieve the sperms.It is a minimal invasive procedure which can be done in local or general anaesthesia.
MICRO TESSE is highly specialized minimally invasive technique where sperms can be retrieved in cases where there is minimal sperm production in testis. This is done under anaesthesia,where sperms are extracted from healthy semniferous tubules of testis after making an incision over testis. The sperms are then washed &fertilized with eggs with the help of ICSI.