Nonobstructive azoospermia (NOA), defined as having no sperm in the semen due to a testicular cellular failure at producing sperm, is the most challenging and complex clinical scenario for infertile men. Besides rare hormonal circumstances causing the sperm count to be zero that can be treated with medication, surgical sperm retrieval is typically necessary, and microdissection testicular sperm extraction (micro-TESE) is the procedure of choice for men with NOA desiring to father children with their own sperm. Micro-TESE results in the highest numbers of sperm cells retrieved for use with in vitro fertilization/intracytoplasmic sperm injection (ICSI) in comparison to all other techniques for surgical sperm retrieval in men with NOA. Several factors may affect sperm retrieval rate and ICSI outcomes, including the patient’s age, testicular volume, histopathological and genetic profile, and serum hormone levels. This article aims to review the medical literature describing predictors of successful micro-TESE and the outcomes of ICSI in men with NOA. Dr. Kavoussi states, “NOA is a very challenging scenario for patients, couples, and the medical providers caring for them. There are so many studies published in the medical literature looking at what predictors might help us understand the odds of successfully finding sperm in these men through microTESE and it can be quite confusing. Our goal with this review was to compile the well-done data in those studies and make sense of the results.”
