Usefulness of 3D reconstruction of low dose pelvic CT as an innovative tool for surgical planning in definitive correction of cloacal malformations

Abstract

Purpose: To describe the results of the use of a low dose pelvic CT protocol for preoperative imaging in cloacal anomalies at a referral center. Methods: We reviewed 43 cases of cloacal anomalies treated at our institution from 2012 to 2022. The patients underwent a cystoscopy under general anesthesia, with measurement of the common channel and the urethra, and visualization of the Müllerian structures, and a Foley catheter was placed in the bladder. Then the patient was transferred to the CT suite for a low dose pelvic CT, filling the bladder, the vagina (by overflow) and the sigmoid/rectum (as in a distal colostogram) with diluted meglumine. Volume rendering was obtained at the CT station. Results: 43 girls with cloaca were treated our institution, 40 of them operated on for correction. The median effective radiation dose was of 2.19mSv (0.81 - 2.96 mSv). The measurement of the common channel had a Pearson coefficient of 0.96 when correlated with the actual measurement. The length was 5 cm in 4. Total urogenital mobilization was possible in 28 patients. We found vaginal duplication in 16, and vaginal reconstruction was performed in 13 others. Conclusion: This technique provided the spatial anatomy of the urinary, vaginal, and colorectal components, with a higher fidelity than fluoroscopy. Since we do not have rotational fluoroscopy, we overcame that limitation with this modality, and found it to be an improvement for planning, allowing for better outcomes.

Keywords

• Cloacal anomalies
• Vaginal anomalies
• 3D imaging
• Cloacogram
• Low dose pelvic CT
• Vaginal replacement