Many azoospermic patients might be candidates for sperm aspiration as part of their in vitro fertilization procedure. Because sperm might be present in some but not all parts of the testes of such men, multiple samplings of the testicular tissue are usually performed to increase the probability of finding sperm in these patients. These samplings can be done in two ways:

  • TESE (testicular sperm extraction), which is actually a surgical biopsy of the testis, or;
  • TESA (testicular sperm aspiration), which is performed by sticking a needle in the testis and aspirating fluid and tissue with negative pressure. Sperm extraction is being performed more and more by non-urologists (called andrologists) who are actually either internists or obstetrician-gynaecologists.

There has always been debate, however, as to which procedure is “better” at obtaining sperm for successful intracytoplasmic sperm injection.