No sperms might be found in male ejaculate for different reasons such as obstructed testicular tracts, genetic factors, or undescended testicles.
TESA, TESE and micro TESE are the most common surgical methods for such cases.
TESA (testicular sperm aspiration) involves retrieval of sperms through aspiration using a needle while TESE (testicular sperm extraction) involves surgical incision of testicles to see if there are any sperms present. Micro TESE is when TESE procedure is done with microsurgery principles using a microscope.
In a man whose ejaculate does not present any sperms, the possibility of finding sperms in his testicles using these methods is approximately 50%.