ABSTRACT
With the advent of intracytoplasmic sperm injection (ICSI), men with nonobstructive azoospermia, previously considered hopelessly infertile, can now potentially initiate a pregnancy, if mature spermatozoa can be harvested from the testes.1-5 Schoysman et al. first demonstrated that spermatozoa extracted from the testis can successfully fertilize human oocytes, leading to pregnancy.6-8 Patients with a predominant histologic pattern of Sertoli-cells-only on testis biopsy can show isolated foci of spermatogenesis in about 25% of cases after a repeat biopsy. Similarly, close to 50% of patients diagnosed with maturation arrest prior to their testicular biopsy are found to have mature spermatozoa on repeat testicular biopsy.9 The corollary, of course, is that mature sperm will not be found in 50-75% of patients with spermatogenic failure, despite meticulous dissection at the time of attempted testicular sperm extraction (TESE).
