3D Fluoroscopic imaging facilitates reconstruction of common urogenital sinus and cloacal anomalies

Abstract

Cloacal anomalies and common urogenital sinus are rare structural abnormalities in hindgut and urogenital development. Surgical correction in childhood is often indicated to create normal external genital anatomy, allow for adequate bladder and vaginal drainage, and create the appropriate anorectal opening in patients with persistent cloaca.

Understanding the anatomy and relationships between the pelvic organs is critical as there is a drastic variation in potential surgical approaches to the repair. Traditional imaging modalities such as pelvic ultrasound, magnetic resonance imaging, and two-dimensional fluoroscopic imaging have been utilized to delineate the pelvic anatomy for facilitation of surgical planning. Limitations to these modalities include the inability to adequately dilate structures and the difficulty in identifying the common confluence, or where the structures ultimately coalesce within the pelvis.

In this article we describe the utilization of three-dimensional rotational fluorosco- py in combination with examination under anesthesia to provide optimal clarity of anatomy. Examination under anesthesia, specifically cystoscopy and vaginoscopy, helps the surgeon to visualize the anatomy and to place catheters in the correct lumens. Contrast material can then be injected into the catheters to dilate the bladder, vagina, and mucous fistula for fluoroscopic imaging. The rotational images can then be reconstructed in three dimensions to create a roadmap for the surgeons, providing accurate description of the location of the confluence, distance to the introitus and other critical measurements.

We believe that three-dimensional rotation fluoroscopy is an underutilized diagnostic modality in the evaluation and surgical planning in patients with urogenital sinus and cloacal anomalies and should be considered by surgeons prior to proceeding with corrective surgery.