Changes in the anal sphincter with age. An endosonographic study

Area of Science:

• Gastroenterology
• Anorectal Physiology
• Medical Imaging

Background:

• Anal endosonography is a key imaging modality for evaluating anorectal structures.
• Understanding age-related changes in anal sphincter muscles is crucial for accurate diagnosis.

Purpose of the Study:

• To investigate the age-related modifications in the endosonographic characteristics of the internal and external anal sphincter muscles.
• To establish normative data for anal sphincter thickness and echogenicity across different age groups.

Main Methods:

• Fifty participants (22-85 years) without anorectal disease underwent anal endosonography.
• Internal and external anal sphincter thickness were measured and correlated with age.
• Internal sphincter measurements included maximum, minimum, and average thicknesses, considering asymmetry.

Main Results:

• A significant positive correlation was observed between age and all measured internal anal sphincter thicknesses (maximum, minimum, average).
• Internal anal sphincter echogenicity increased with age, indicating muscle changes.
• No significant correlation was found between external anal sphincter thickness and age.

Conclusions:

• Age-dependent changes in internal anal sphincter thickness and echogenicity are significant.
• Endosonographic findings aid in identifying internal anal sphincter hypertrophy.
• Abnormal maximal internal sphincter thickness is defined as >4 mm for <50 years and >5 mm for ≥50 years.