Value of contrast-enhanced colosonography in the assessment of anorectal malformations.

BACKGROUND

Anorectal malformations are common congenital anomalies. Accurate preoperative imaging of fistulous connections is crucial for surgical planning. Traditional imaging uses ionizing radiation and often requires sedation. Contrast-enhanced colosonography, based on the application of ultrasound contrast agents, has been developed to overcome these limitations while still providing high-resolution structural information for the evaluation of anorectal malformations. The indications of laparoscopically assisted anorectoplasty for recto-bulbar urethral fistulas remain debated.

OBJECTIVES

This study aimed to evaluate the diagnostic accuracy of contrast-enhanced colosonography in detecting anorectal malformations and its value in guiding surgical approach selection.

MATERIALS AND

METHODS

The diagnostic performance of preoperative contrast-enhanced colosonography and fluoroscopic colostography was compared in 72 cases, with surgical findings serving as the reference standard. Additionally, the relationship between surgical approach and the data from recto-urethral fistula was evaluated.

RESULTS

Contrast-enhanced colosonography showed higher sensitivity for fistula detection rate than fluoroscopic colostography (98.6% vs. 83.3%, P<0.001). Concordance with surgical anatomy was 98.6% for contrast-enhanced colosonography, while 73.6% for fluoroscopic colostography. Among patients with recto-bulbar urethral fistula, a pouch-perineum (P-P) cutoff value of 23.5 mm (sensitivity 66.7%, specificity 76.0%) yielded an area under the curve of 0.747 (P=0.01, 95% CI 0.589-0.904).

CONCLUSION

Contrast-enhanced colosonography appears to be a safe, effective, and versatile method for obtaining critical preoperative structural information in patients with anorectal malformations. For patients with recto-urethral fistulas, contrast-enhanced colosonography enables further differentiation between recto-membranous and recto-bulbar urethral fistulas. In specified cases, the P-P measurement may be helpful in selecting the appropriate surgical approach.