Having a sperm count of zero is not a diagnosis that any man expects to receive; however, it impacts 1% of men in the general population and 15% of men who present for fertility evaluations. It is important to differentiate whether the absence of sperm is due to a blockage, known as obstructive azoospermia (OA), or to testicular dysfunction resulting in sperm production failure, known as non-obstructive azoospermia (NOA).
Clinical clues that help make this distinction include testicle sizes, dilation of the tubes where sperm leave the testicles (epididymides), semen volume, and a blood test called follicle-stimulating hormone (FSH). FSH has been traditionally thought to be the definitive indicator between the two diagnoses, as it is elevated in the majority of men with NOA, but not all.
The differentiation between the two dictates whether the man needs an in-office minor procedure called a testicular sperm extraction (TESE) in OA cases or a much more complex microdissection testicular sperm extraction (microTESE) in the operating room under anesthesia for the NOA cases. The goals of both are sperm retrieval for use with IVF. Dr. Parviz Kavoussi performs both procedures frequently with extremely high success rates.
There are cases that are very difficult to distinguish between OA and NOA based on these clinical clues, so current guidelines recommend a diagnostic testicular biopsy to differentiate between them. The problem with this approach is that a diagnostic testicular biopsy is an invasive procedure, requires additional recovery and cost, violates the testicle which could possibly impact areas of sperm production, and may delay time to IVF, which can be a significant disadvantage in couples with female partners with low ovarian reserve.
To address this challenge, Dr. Kavoussi published a study proposing a new algorithm for men with uncertain diagnoses. This approach involves proceeding to the operating room (OR) under anesthesia for a simple TESE, with preparation to immediately go to a microTESE if needed. A laboratory team is present in the OR to assist in guiding this decision.
Dr. Kavoussi states, “Our study indicated that over two-thirds of the men in this group, those who could not be definitively classified as OA or NOA based on clinical clues alone, despite a normal FSH level, had testicular pathology that ultimately confirmed NOA. This meant their odds of finding sperm through a simple office-based TESE would have been very low, potentially requiring a second procedure for microTESE at a later time. This new algorithm would allow all options to be addressed in a single surgical setting.”
