A comparison between electromyography and anal endosonography in mapping external anal sphincter defects

Area of Science:

• Gastroenterology and Colorectal Surgery
• Medical Imaging and Diagnostics

Background:

• Fecal incontinence following perineal trauma can result from external anal sphincter defects.
• Accurate assessment of these sphincter defects is crucial for effective management.
• Electromyography has been used for mapping sphincter defects, but patient tolerance can be an issue.

Purpose of the Study:

• To compare the diagnostic accuracy of anal endosonography with electromyography for external anal sphincter defects.
• To evaluate the correlation between these two methods in patients with post-traumatic fecal incontinence.
• To assess patient tolerance of anal endosonography compared to electromyography.

Main Methods:

• Anal endosonography and electromyography were performed in 15 patients with fecal incontinence after perineal trauma.
• Mapping of the external anal sphincter was conducted using both techniques.
• Agreement and discrepancies in defect location and size were analyzed.

Main Results:

• Both methods identified no defects in 3 patients.
• High agreement was observed in identifying the quadrant of the defect in 12 patients (100%).
• A high correlation (r = 0.96; P < 0.01) was found between anal endosonography and electromyography findings.
• Anal endosonography demonstrated better patient tolerance than electromyography.

Conclusions:

• Anal endosonography is a highly accurate and well-tolerated method for assessing external anal sphincter defects.
• It serves as a valuable alternative to electromyography for diagnosing post-traumatic sphincter injuries.
• This imaging modality aids in understanding the structural integrity of the external anal sphincter in fecal incontinence.