Functional and Anatomical Significance of Patulous Anus

Area of Science:

• Anorectal physiology and imaging
• Gastroenterology
• Pelvic floor disorders

Background:

• A patulous anus is often associated with anal sphincter injury and fecal incontinence (FI).
• Understanding the clinical significance of a patulous anus identified on MRI defecography (MRD) is crucial for patient management.

Purpose of the Study:

• To investigate the clinical and functional significance of a patulous anus as detected by MRI defecography (MRD).
• To correlate MRD findings with anorectal manometry and clinical symptoms.

Main Methods:

• Retrospective review of patients with and without a patulous anus.
• Analysis of clinical characteristics, anorectal manometry, MRD findings, and symptom severity scores.
• Stepwise logistic regression to identify independent predictors of a patulous anus.

Main Results:

• A patulous anus was identified in 29% of patients, predominantly women, who were older and had a history of pelvic surgery.
• Patients with a patulous anus reported higher rates of fecal incontinence (FI) with worse Wexner scores and reduced anal pressures.
• MRD revealed higher grades of rectal intussusception, longer levator hiatus, greater perineal descent, and a wider anorectal angle at rest in patients with a patulous anus.

Conclusions:

• A patulous anus on MRD signifies important underlying anorectal anatomical and functional abnormalities.
• Screening for fecal incontinence (FI) and advanced rectal intussusception is warranted in patients with a patulous anus.
• MRD is a valuable tool for assessing anorectal function and identifying structural abnormalities associated with a patulous anus.