Accuracy of hydrogen peroxide‐enhanced ultrasound in the identification of internal openings of anal fistulas

Abstract

OBJECTIVE: This prospective study was designed to assess the accuracy of hydrogen peroxide-enhanced ultrasound in the identification of internal openings of anal fistulas, with surgical findings as the golden standard. PATIENTS AND METHODS: A total of 143 consecutive patients (102 men; mean age, 45 years) with fistula-in-ano were assessed by hydrogen peroxide-enhanced ultrasound before surgery involving one radiologist. Ultrasound was performed using a B & K Diagnostic Ultrasound System trade mark with a 10-MHz rotating endoprobe. Hydrogen peroxide (3%) was infused into the fistula. All operations were perfomed by the same surgeon who was unaware of results of anal endosonography. RESULTS: In 128 (89.5%) patients, an internal opening was identified at surgery. Correct identification of an internal opening endosonographically was recorded in 80 (62.5%) patients. The internal opening was correctly identified by ultrasound in 32% (8/25) of patients with intersphincteric fistulas, in 77% (70/91) with transsphincteric fistulas, and in 17% (2/12) with suprasphincteric fistulas. CONCLUSION: The accuracy of hydrogen peroxide-enhanced anal endosonography for the identification of internal openings was still insufficient to justify pre-operative endosonography as a diagnostic method for routine use in patients with fistula-in-ano.

Ultrasound Study of Anal Fistulas With Hydrogen Peroxide Enhancement

“…However, it seems that the accuracy of endosonography depends to a large extent on the criteria used to identify the internal opening rather than on the technique of endoanal ultrasound. In studies in which the three criteria were used, the accuracy of H 2 O 2 -enhanced ultrasound for detecting the internal opening was 68 percent, 3 which is higher than the 62 percent reported in our study using two criteria, 4 and much higher than 48 percent reported by Poen et al, 5 who used only criterion III.…”

Randomized clinical trial of anal fistula plugversusendorectal advancement flap for the treatment of high cryptoglandular fistulain ano

“…Patients were selected before operation based on digital examination, proctosigmoidoscopy and hydrogen peroxide-enhanced ultrasonography 13 . Those with a history of fistula surgery also underwent magnetic resonance imaging studies.…”

Transperineal versus hydrogen peroxide-enhanced endoanal ultrasonography in never operated and recurrent cryptogenic fistula-in-ano: a pilot study

“…In this respect, endoanal ultrasonography (EAUS) has become a mainstay in the preoperative assessment of complex fistulae-in-ano [5], showing a high sensitivity and positive predictive value for comparison of fistula anatomy with surgery [6,7]. Cheong and colleagues were the first to describe hydrogen peroxide-enhanced EAUS in anorectal sepsis [8], where its addition has been shown to have a higher sensitivity for the detection of the internal fistula opening in both cryptogenic never operated [9] and recurrent [10] fistulae-in-ano.…”