Introduction: Previous studies concerning ultrasound evaluation of the seminal vesicles (SV) have been performed on a limited series of subjects, taking into consideration few parameters, often only before ejaculation and without assessing sexual abstinence of the patients. The aim of this study is to evaluate the volume and the emptying characteristics of the SV and their possible correlations with scrotal and transrectal ultrasound features.
Methods: The SV of 368 men seeking medical care for couple infertility have been evaluated by ultrasound. All patients underwent simultaneous seminal analysis, along with scrotal and transrectal ultrasound, before and after ejaculation. A new parameter, SV ejection fraction, calculated as ((SV volume before ejaculation−SV volume after ejaculation)/SV volume before ejaculation)×100, was evaluated.
Results: After adjusting for sexual abstinence and age, both pre-ejaculatory SV volume and SV ejection fraction were positively associated with ejaculate volume. As assessed by receiver operating characteristic (ROC) curve, at 21.6% SV ejection fraction discriminates subjects with normal ejaculate volume (≥ 1.5 ml) and pH (≥7.2 ml) with a sensitivity and specificity of 75%. Subjects with reduced SV ejection fraction (<21.6%) more often had higher post-ejaculatory SV volume and ejaculatory duct abnormalities. Furthermore, a higher post-ejaculatory SV volume was associated with a higher prostate volume and SV abnormalities. Higher epididymal and deferential diameters were also detected in subjects with a higher post-ejaculatory SV volume or reduced SV ejection fraction. No association between SV and testis ultrasound features or sperm parameters was observed. Associations with SV ejection fraction were confirmed in nested 1:1 casecontrol analysis.
Conclusions: SV mainly contribute to ejaculate volume. A new parameter, SV ejection fraction, has been investigated, and could be useful in assessing SV emptying. Reduced SV ejection fraction (<21.6%) is associated with prostate-vesicular and epididymal ultrasound abnormalities.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.
05 - 09 May 2012
European Society of Endocrinology