Diagnosis of anal sphincter defects by three-dimensional transperineal ultrasound in women with anal incontinence

Purpose To assess the utility of transperineal threedimensional (3D) ultrasound for diagnosing anal sphincter defects and evaluating the function of the anal canal in women with anal incontinence. Methods The study subjects were 13 women with anal incontinence. Symptoms of fecal incontinence were assessed by Wexner score. The anal canal of each woman was examined ultrasonically with both a convex transperineal 3D scanner and a radial transanal scanner to compare the accuracy of the two approaches for diagnosis of anal sphincter defects. The anorectal angle and the length of the anal canal were also measured by utilizing the functionality of the transperineal 3D ultrasound. Results The mean age was 58.9 ± 14.9 years (±SD), and the mean Wexner score was 8.4 ± 5.6. In terms of ultrasound diagnosis of anal sphincter defects, the two methods showed consistent results in each woman. The length of the portion where both the internal and external anal sphincters were intact was significantly correlated with the Wexner score, whereas the total length of the anal canal was not. Conclusions Less invasive transperineal 3D ultrasound provides accurate evaluation of the internal and external anal sphincters in women with anal incontinence, and the method is potentially useful for detection of anal sphincter abnormalities.