Aim. To evaluate the effect of microsurgical subinguinal varicocelectomy on sperm DNA fragmentation (SDF) in patients with elevated SDF levels (more than 15%) and clinical varicocele.
Materials and methods. A single-center, retrospective, observational, uncontrolled study was carried out. The results of a survey of 33 patients with clinical varicocele, infertility or recurrent miscarriage and sperm DNA fragmentation of more than 15% were analyzed. All patients in 2021–2022 underwent microsurgical subinguinal varicocelectomy at the clinic «Mother and Child Yaroslavl». The level of sperm DNA fragmentation was assessed before and 3 months after varicocelectomy using TUNEL assay based on flow cytometry.
Results. The level of SDF before surgery ranged from 17 to 73% (Me [Q1–Q3]: 32% [21–42]). After 3 months, it ranged from 1 to 27% (14,4% [7,5–17,4]). The differences between the groups were significant (p <0.001). In all patients, SDF levels after varicocelectomy were lower compared to baseline. The differences ranged from 4 to 55% (19,1% [9,5–25,7]). In 21 patients (63.6%) SDF level after treatment did not exceed the upper limit of the reference interval (15%), and in 11 (35.4%) patients the postoperative values were higher than 15%. A significant (p<0.001) positive correlation (r=0.626) was revealed between the preoperative SDF level and the degree of reduction in sperm DNA fragmentation. However, no correlation was found with other preoperative indicators (varicocele degree, patient age, body mass index, side of varicocele).
Conclusion. Performing microsurgical subinguinal varicocelectomy in patients with an increased SDF level (more than 15%) allows reducing SDF within 3 months by an average of 19.1% and achieving normative values in 63.6% of men. The degree of reduction in SDF after varicocelectomy positively correlates with preoperative values.

Keywords: microsurgical subinguinal varicocelectomy, sperm DNA fragmentation, varicocelectomy, varicocele