Brief Articles
Copyright ©2009 The WJG Press and Baishideng. All rights reserved.
World J Gastroenterol. Oct 14, 2009; 15(38): 4810-4815
Published online Oct 14, 2009. doi: 10.3748/wjg.15.4810
Three-dimensional endoanal ultrasonographic assessment of an anal fistula with and without H2O2 enhancement
Yung Kim, Young Jin Park
Yung Kim, Young Jin Park, Department of Surgery, Dongguk University Ilsan Hospital, Dongguk University School of Medicine, Goyang-si, Gyeonggi-do 410-773, South Korea
Author contributions: Kim Y performed the data collection and analysis; Park YJ designed the study, performed the clinical evaluation and wrote the manuscript.
Correspondence to: Young Jin Park, MD, Professor of Surgery, Department of Surgery, Dongguk University Ilsan Hospital, 814, Siksa-dong, Ilsandong-gu, Goyang-si, Gyeonggi-do 410-773, South Korea. parkyj@duih.org
Telephone: +82-31-9617262 Fax: +82-31-9617977
Received: June 22, 2009
Revised: July 22, 2009
Accepted: July 29, 2009
Published online: October 14, 2009
Abstract

AIM: To evaluate the effectiveness of three-dimensional endoanal ultrasound (3D-EAUS) in the assessment of anal fistulae with and without H2O2 enhancement.

METHODS: Sixty-one patients (37 males, aged 17-74 years) with anal fistulae, which were not simple low types, were evaluated by physical examination and 3D-EAUS with and without enhancement. Fistula classification was determined with each modality and compared to operative findings as the reference standard.

RESULTS: The accuracy of 3D-EAUS was significantly higher than that of physical examination in detecting the primary tract (84.4% vs 68.7%, P = 0.037) and secondary extension (81.8% vs 62.1%, P = 0.01) and localizing the internal opening (84.2% vs 59.7%, P = 0.004). A contrast study with H2O2 detected several more fistula components including two primary suprasphincteric fistula tracks and one supralevator secondary extension, which were not detected on non-contrast study. However, there was no significant difference in accuracy between 3D-EAUS and H2O2-enhanced 3D-EAUS with respect to classification of the primary tract (84.4% vs 89.1%, P = 0.435) or secondary extension (81.8% vs 86.4%, P = 0.435) or localization of the internal opening (84.2% vs 89.5%, P = 0.406).

CONCLUSION: 3D-EAUS was highly reliable in the diagnosis of an anal fistula. H2O2 enhancement was helpful at times and selective use in difficult cases may be economical and reliable.

Keywords: Anal fistula, Endoanal ultrasound, H2O2 enhancement