It is caused by the obstruction, incomplete canalization, or failure of canalization during the upward cavitation of the vaginal plate, which evolves from the urogenital sinus—the vaginal bulb—proliferating and elongating toward the cephalic end during the embryonic stage. This condition often occurs at the junction of the upper and middle third of the vagina but can also occur at any part of the vagina, extending up to the vaginal apex near the cervix.

bubble_chart Clinical Manifestations

The thickness of the transverse septum varies greatly, with some being as thin as paper, while others are relatively thick (1–1.5 cm). The interstitial tissue between the two layers of the adhesive membrane may contain abundant collagen fibers and smooth muscle, occasionally mixed with mesonephric-like tissue components. The presence of clinical symptoms depends entirely on whether the septum has small perforations. Complete transverse septa are rare; most have a small perforation in the center of the septum, sometimes only large enough for a fine probe. If menstrual blood can flow out, symptoms may not appear until after marriage, when dyspareunia or obstructed labor due to the fetal head occurs. If there is no perforation, symptoms will manifest after menarche due to hematometra. When examining a vaginal transverse septum, the first step is to check for small perforations (often in the central area). If perforations are present, a probe can be inserted to explore the width and depth of the vagina above the perforation to confirm the diagnosis.

bubble_chart Diagnosis

When examining a vaginal septum, the first step is to check for the presence of a small opening (often in the central area) on the septum. If a perforation is found, a probe can be inserted into the hole to explore the width and depth of the vagina above the small opening for diagnostic purposes.

During surgical excision, use the small hole as a reference point and make an X-shaped incision outward until reaching the vaginal wall. If the membrane is thin, the excess tissue of the septal membrane can be circumferentially excised. The two layers of the mucosal membrane at the incision are slightly freed from the base and sutured longitudinally, creating a zigzag suture line that avoids a single plane to prevent future annular stenosis. If the membrane is thick, first make an X-shaped incision on the outer mucosal surface to a depth of half the thickness of the transverse septum, then separate the mucosal flaps. Next, make a cross-shaped incision on the inner layer, and interlock and suture the four pairs of outer and inner mucosal flaps in a staggered fashion to prevent postoperative stenosis due to scar contracture. If pregnancy occurs later, childbirth often cannot proceed smoothly, necessitating a cesarean section to complete delivery.