Extrasphincteric anal fistula with gluteal extension: A case report and literature review

Anal fistulas typically result from infected anal glands, presenting with symptoms like recurrent purulent discharge, pain, and itching around the anus. Infections are commonly located in the skin, soft tissues, or spaces surrounding the rectum and anal canal. Notably, extensive subcutaneous tissue infections in the buttocks are exceedingly uncommon. Distinguishing this condition from anal fistulas associated with Crohn disease poses a significant diagnostic challenge.

A 27-year-old female patient presented with pain, swelling, and purulent discharge in the buttocks persisting for 6 months, with a recent exacerbation over the last 2 days.

The diagnoses were established through a comprehensive medical history assessment, physical examination, enhanced magnetic resonance imaging of the anal canal, and electronic colonoscopy, revealing: complex anal fistula, infected sinus in the buttock area, constipation, and mild anemia.

The surgical intervention involving complete fistula dissection, excision of the affected area's apex in the buttocks, removal of necrotic material, fibrous tissue debridement, and thread-draped drainage facilitated fistula tract healing and markedly enhanced patients' quality of life.

After treatment, the patient showed no purulent discharge, swelling, or pain in the buttocks, and there was no bleeding or fluid leakage. The patient was followed up for 18 months after the treatment, and the wound healed well, with a satisfactory treatment outcome.

In the context of diagnosing and treating anal fistulas, it is crucial to abandon the notion that infection is limited to the perianal region. Utilizing advanced magnetic resonance imaging of the anal canal is essential for precise localization, while employing a combination of diagnostic examinations is warranted for accurate differential diagnosis. Postsurgical follow-up of anal fistula patients for a minimum of 1 year is advisable to monitor recurrence and address predisposing factors like constipation. In instances of uncommon variants, it is advisable to engage in multidisciplinary cooperation to synthesize insights from various specialties, thereby enhancing the scientific rigor of diagnostic and therapeutic approaches.