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Updated: Oct 17, 2025
Flow Cytometric Analysis of Biomarkers for Detecting Human Sperm Functional Defects
Published on: April 21, 2022
Peak retrograde flow a potential objective management tool to identify young adults with varicocele 'at risk' for a
G De Win1, D De Neubourg2, S De Wachter1
1Department of Urology, Antwerp University Hospital, Wilrijkstraat 10, 2650, Edegem, Belgium; Department of Urology, Antwerp Surgical Training, Anatomy and Research Centre (ASTARC), Faculty of Medicine and Health Sciences, Wilrijk, Belgium.
Introduction:
Determining which patients are negatively affected by varicocele would enable clinicians to better select those men who would benefit most from surgery. Since conventional semen parameters, have been limited in their ability to evaluate the negative effects of varicocele on fertility, specialized laboratory tests have emerged.
Objective:
To identify clinical and ultrasound parameters (including PRF) which would negatively influence standard and functional semen variables in young adults with a varicocele.
Design:
Prospective, cross-sectional observational study.
Setting:
Antwerp University Hospital, Belgium.
Patient(S):
Young volunteers between 16 and 26 years, Tanner 5, were recruited.
Intervention(S):
Every participant had a scrotal ultrasound to calculate testicular volumes. If a varicocele was present, the grade, vein diameter, peak retrograde flow (PRF) in supine position and spontaneous reflux in standing position were measured. All participants provided a semen sample. Standard semen parameters were analyzed and sperm DNA fragmentation.
Main Outcome Measure(S):
Of all clinical and ultrasound parameters tested, PRF was an objective tool identifying young adults with a varicocele. PRF was highlighted by the prevalence of SDF, both in the total and vital fractions of the spermatozoa, providing opportunities to manage such 'at-risk' adolescents/young adults.
Result(S):
Total SDF was significantly increased in grade 3 varicocele compared to grade 1 and 2 but no significant difference with vital SDF or standard descriptive semen parameters was seen. Total and vital SDF on the other hand were significantly increased when PRF was above 38.4 cm/s. Standard semen analysis showed no difference with PRF as an independent predictor. Testicular atrophy index, varicocele vein diameter and spontaneous reflux revealed no significant differences in both the descriptive and functional semen variables.
Discussion:
Descriptive semen parameters showed no significant difference between the non-varicocele controls and the varicocele group with low and high PRF. Increased PRF negatively influenced sperm quality via increased DNA fragmentation both in the total as in the vital fractions of the semen.
Conclusion(S):
Of all clinical and ultrasound parameters tested, PRF was an objective non-invasive tool to identify varicocele patients at risk for a high SDF.
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