Freezing a few testicular spermatozoa retrieved by TESA

Men with azoospermia can now be treated using testicular sperm aspiration (TESA). New aspirations, in subsequent cycles, may be avoided using cryopreservation. Conventional sperm freezing techniques are not suitable for TESA samples with a small number of spermatozoa. Testicular spermatozoa were obtained from 10 azoospermic men undergoing TESA for a diagnostic objective. Two different freezing protocols were performed according to the number of spermatozoa found in the final suspension: between 100-2000, we used TEST yolk buffer with glycerol, adding it to testicular sperm (Method I); for less than 100, we injected them into cell-free human zona pellucida before adding a freezing medium (Method II). Sperm and motility recovery rates were 1% and 32.3%, and 88.2% and 26.6% for methods I and II respectively. The fertilisation rate was 13.3% and 23% for methods I and II respectively. This study represents our preliminary experience in freezing testicular spermatozoa collected by TESA. Preliminary observations show that it is possible to freeze a few testicular spermatozoa inside evacuated zona pellucida.