MRI-based Stratification and Surgical Management of Hydrocolpos in Children and Adolescents

In this report we present a new anatomical stratification for vaginal obstruction (hydrocolpos) based on MRI findings while referring the level of obstruction to a fixed bony landmark (the pubic symphysis). This new approach can overcome the limitations of current classifications, which are prone to approximation errors during measurement and fail to account for variations in body mass across different age groups.Data of cases diagnosed with vaginal obstruction were retrospectively analyzed. Cases of cloaca with vaginal obstruction were excluded. MRI confirmed the diagnosis and enabled classification of the level of vaginal obstruction relative to the pubic symphysis in the mid-sagittal plane as low, intermediate, or high-opposite the lower, mid, or upper end of the pubic symphysis, respectively.A total of 13 girls presented with vaginal obstruction during the period 2010 through 2024. Their age ranged between 1 month and 14 years (mean: 54 months; median: 18 months). Three cases presented in the neonatal period with antenatal diagnosis of hydrocolpos, while six cases were referred later during infancy/childhood from other centers. Another group of adolescent girls (four cases) presented with a clinical picture of cryptomenorrhea. The cause of vaginal obstruction was imperforate hymen in one, vaginal atresia in six, persistent urogenital sinus (five cases), and one case of obstructed hemi-vagina. In this series, six cases (46%) had features related to genetic syndromes (Bardet Biedl/ McKusick-Kaufman spectrum). Chronic parenchymatous renal disease was present in three cases among other syndromic features of Bardet Biedl syndrome, in addition to another case with obstructed left hemi-vagina that had absent left kidney (Herlyn-Werner-Wunderlich syndrome). Surgical techniques included simple excision of distal obstructing membrane (four cases), abdominal assisted vaginoplasty (two cases), vaginal pull-through (four cases), simple introitoplasty (one case), urogenital sinus mobilization (one case), and division of longitudinal vaginal septum for a case of obstructed hemi-vagina. Vaginal stenosis or retraction occurred in three cases with intermediate to high-level obstruction-two following abdominal assisted vaginoplasty and one after vaginal pull-through.MRI-based stratification of vaginal obstruction using the pubic symphysis as a reference provides a practical and reproducible approach for surgical planning.This is a case series (level IV evidence).