Accuracy of Endocavitary and Transperineal Ultrasound in Evaluating Fistula-in-Ano
DOI:
https://doi.org/10.54133/ajms.v10i1.2643Keywords:
Diagnostic accuracy, Endocavitary ultrasound, Fistula in ano, MRI, Parks classification , Transperineal ultrasoundAbstract
Background: Fistula-in-ano is an abnormal connection between the anal canal and the skin of the perineum, affecting 1.7-2.3/10,000 persons/year. Appropriate evaluations and imaging are necessary to decrease recurrence rate. Objective: Determining accuracy of endocavitary and transperineal ultrasound relative to magnetic resonance imaging in evaluation of perianal fistulas. Methods: A cross-sectional study was conducted on 40 patients with perianal fistula. Endocavitary, transperineal ultrasound and magnetic resonance imaging (MRI) were done for all patients. Many variables were recorded, including location, number of tracts, their relation to the anal sphincters (course), internal opening, external openings, length of tract, distances from the anal verge, and any associated abscess or side branching. Results: Of the 40 patients studied, both modalities showed compatibility between US and MRI for location of fistula, nearly perfect for opening to skin and opening to anal mucosa, and substantial for course of fistula, association collection, and side branching. For fistula length, the analysis revealed a statistically significant mean bias of 4.575 (p<0.001), indicating that MRI measurement is higher than US. For distance from anal verge bias, it is 2.575 (p<0.001), with the MRI measurement being higher than the US. Conclusions: Ultrasonography is a reliable, cost-effective alternative to MRI for assessing fistula in ano. Although MRI may still be preferred for more complex cases, ultrasound demonstrated high agreement in evaluating location, opening positions, course of fistula, and associated anatomical features.
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