Purpose: This study was designed to assess the natural history of subclinical varicocele in the pediatric age group.
Materials and methods: We conducted a school screening for varicocele in 2,107 children 10 to 16 years old, performing clinical examination and venous Doppler study. A total of 354 boys (16.8%) without clinically detectable varicocele had venous testicular reflux during a Valsalva maneuver. Of these children 36 (a 10% sample) were selected randomly and followed annually for 4 years, with assessment of testicular volume (ultrasound values), degree of varicocele according to the Dubin and Amelar classification, and Doppler findings according to the Hirsh testicular Doppler classification. The control group consisted of 20 children selected randomly from the same population, who did not have a varicocele and had a normal Doppler study. Fisher's exact test was used with a significance value at p <0.05.
Results: Mean age of the 36 children at the first assessment was 12.8 years (SD 1.7). Two boys (5.5%) had spontaneous resolution of testicular venous reflux within 2 years, and in 24 (67%) the subclinical varicocele did not change. The remaining 10 children (28%) had a clinically detectable varicocele, which was grade I in 1 patient, grade II in 7 and grade III in 2. Of these patients 1 had associated left testicular hypoplasia greater than 20%. During the 4-year period there were no clinically detectable varicoceles in the control group (p = 0.01).
Conclusions: The proportion of children with subclinical varicocele progressing to a clinically detectable form of the condition was 28% (95% CI 14 to 45) during a 4-year period. We suggest that children with subclinical varicocele require long-term followup.