PESA & TESE are used in male with azoospermia. Sperm can be detected in epididymis or testicles in some cases and used to fertilize with stimulated egg from IVF.
PESA (Percutaneous Epididymal Sperm Aspiration) is the use of a needle to pierce testicles skin into the seminal tubes and pull out sperm for ICSI.
TESA (Testicular Sperm Aspiration) is the surgery to cut into testicles and retrieve sperm inside for ICSI.
MESA (Microsurgical Epididymal Sperm Aspiration) is the surgery into the epididymis via microscope and pull out sperm for ICSI.