Testicular ultrasonic microvascular density in assessing spermatogenesis and predicting successful sperm retrieval.

ABSTRACT

Background: The relationship between microcirculatory disorders and testicular spermatogenesis is an area of ongoing interest among urologists. The objective of this prospective observational study was to investigate the correlation between testicular microcirculation and spermatogenesis, as well as the predictive value of ultrasonic microvascular density (UMVD) and ultrasonographic volume estimation (UVE) in successful sperm retrieval among men with non-obstructive azoospermia (NOA). Methods: Testicular UMVD derived from Angio PLUSTM Planwave Ultrasensitive Imaging (AP), UVE were obtained. Participants were divided into 4 groups (normozoospermia; asthenozoospermia, teratozoospermia, or asthenoteratozoospermia; oligozoospermia; NOA). Results: The study included a total of 875 participants. No significant difference was found in UMVD-mean between different semen groups (P>0.05). A total of 108 participants with NOA underwent microdissection testicular sperm extraction (micro-TESE). Participants with successful sperm retrieval (40 cases) showed significant differences in testicular UMVD and UVE compared to those with negative retrieval (68 cases) (P<0.01). We generated receiver operating characteristic (ROC) curves for UMVD and testicular UVE to differentiate participants with successful sperm retrieval from those without. The area under the curve (AUC) was 0.760 [95% confidence interval (CI) 0.658-0.849, P<0.01] for UMVD and 0.716 (95% CI 0.609-0.822, P<0.01) for testicular UVE, respectively. The optimal cutoff value was determined based on the maximum Youden index. When UMVD was set at 28.50/cm2, its sensitivity and specificity were calculated as 57.5% and 85.3%, respectively. For testicular UVE, a cutoff value of 8.94 mL resulted in a sensitivity of 60.0% and specificity of 82.4%. Combining UMVD with testicular UVE improved diagnostic performance (AUC 0.856, 95% CI 0.772-0.929, P<0.01) with a sensitivity of 79.4% and specificity of 77.5%. Conclusions: The present study demonstrates the utility of AP as a predictive tool for successful sperm retrieval prior to micro-TESE. Furthermore, the combination of testicular UMVD and UVE provides a highly valuable diagnostic approach for predicting micro-TESE success and can be routinely implemented before the procedure. A testicular UMVD exceeding 28.50/cm2 and a testicular UVE larger than 8.94 mL strongly indicate favorable outcomes in terms of sperm retrieval.