Intratesticular Doppler flow, seminal plasma nitrites/nitrates, and nonobstructive sperm extraction from patients with obstructive and nonobstructive azoospermia.

To prospectively evaluate the role of intratesticular vascular flow in modulating sperm function in men with obstructive and nonobstructive azoospermia. The correlation of testicular Doppler values with nitric oxide and testicular sperm extraction was further evaluated.Prospective study.Assisted reproduction unit at a university center.Twenty-eight men with azoospermia undergoing sperm extraction for intracytoplasmic sperm injection.Ultrasound and color Doppler scanning of the testes. Testicular sperm retrieval and nitrite/nitrate assay.Doppler analysis of testicular transmediastinal artery, plasma and seminal plasma nitrite/nitrate values, and sperm extraction histopathology.The pulsatility index (PI) of the transmediastinal artery was higher in patients with nonobstructive azoospermia (PI = 1.40 +/- 0.13) than in those with obstructive azoospermia (PI = 1.09 +/- 0.15; P=.011). Seminal plasma nitrite/nitrate concentrations were more elevated in cases of obstructive azoospermia than in gonadal failure. Unsuccessful sperm recovery was observed in four patients who showed the worst indices of gonadal failure. In this subgroup, a transmediastinal PI value >1.50 was always observed.Doppler analysis of the transmediastinal artery and nitrite/nitrate seminal plasma concentrations are useful for distinguishing between obstructive and nonobstructive azoospermia and allow the identification of the presence of spermatozoa within the testes.