Value of transperineal sonography in the assessment of vaginal atresia.

We studied the value of transperineal sonography in the preoperative assessment of seven patients with clinically suspected vaginal atresia. Although transabdominal scanning is useful to determine if hydrocolpos or hydrometrocolpos is present, this method does not allow measurement of the thickness of a caudally placed obstructive septum. This information is useful in planning reconstructive surgery. All seven patients had transabdominal sonography, with five showing a low-lying obstruction. In those five patients, the distance between the perineal surface and the caudal aspect of the distended vagina, measured with electronic calipers on the transperineal sonograms, ranged from 1.0 to 4.0 cm. We conclude that when vaginal atresia is clinically suspected, transabdominal sonography should be performed to confirm the diagnosis. When a low-lying obstruction is identified, transperineal sonography should be performed to determine the length of the obstructive segment.