Evaluating postoperative anal fistula prognosis by diffusion-weighted MRI

Area of Science:

• Gastroenterology
• Radiology
• Surgical Oncology

Background:

• Anal fistula is a common anorectal condition.
• Postoperative recurrence remains a significant challenge in anal fistula management.
• Accurate preoperative assessment is crucial for predicting treatment outcomes.

Purpose of the Study:

• To evaluate the utility of preoperative diffusion-weighted magnetic resonance imaging (DW-MRI) in assessing anal fistula prognosis.
• To identify factors influencing postoperative recurrence of anal fistulas.

Main Methods:

• Retrospective analysis of 82 patients with anal fistula who underwent preoperative DW-MRI and surgery.
• Measurement of apparent diffusion coefficient (ADC) values of the fistula.
• Correlation of ADC values and MRI-based severity scores with recurrence.
• Analysis of clinical factors, including presence of perianal abscess and fistula complexity.

Main Results:

• Lower ADC values were significantly associated with recurrence in patients with perianal abscess (p=0.03).
• ADC values showed a significant negative correlation with MRI-based fistula severity scores (r=-0.332, P=0.002).
• Risk factors for recurrence included time interval between MRI and surgery, multiple fistula tracks, and lifestyle factors.

Conclusions:

• DW-MRI, particularly ADC values, holds significant value in predicting the prognosis of anal fistulas.
• Complex fistula types and modifiable lifestyle factors are key determinants of postoperative recurrence.