Materials and Methods: This retrospective observational study included patients who underwent unilateral subinguinal microsurgical varicocelectomy between January 2022 and June 2025. Preoperative CDUS venous diameters (at rest and during Valsalva), clinical varicocele grade, intraoperatively excised pathological venous diameters, and semen analysis parameters were recorded. Improvement after varicocelectomy was defined as a ≥10% increase in sperm concentration and/or progressive motility. Correlation analyses and univariate and multivariate logistic regression models were used to identify predictors of postoperative improvement.

Results: A total of 55 patients were analyzed, of whom 44 (80.0%) demonstrated postoperative improvement in semen parameters. Pathological venous diameter was significantly larger in the improved group compared with the non-improved group (3.30 vs. 2.98 mm, p = 0.026). Pathological venous diameter showed a significant positive correlation with clinical grade (r = 0.307, p = 0.023), but not with CDUS-measured venous diameters. In multivariate analysis, higher clinical grade (Grade 2: OR = 4.523; Grade 3: OR = 6.544), larger pathological venous diameter (OR = 2.149), and lower preoperative sperm concentration (OR = 0.928) were independent predictors of postoperative semen improvement. CDUS-derived venous diameters were not predictive.

Conclusion: Pathological venous diameter and clinical varicocele grade appear to be more informative than CDUS-measured venous diameter in predicting semen parameter improvement after varicocelectomy. These findings suggest that the anatomical extent of venous dilation may better reflect the potential reversibility of varicocele-related testicular dysfunction.