Perianal and rectovaginal fistulae are common complications in Crohn's disease. Magnetic resonance imaging (MRI) and endoanal ultrasound are used for imaging perianal fistulae and abscesses, but both methods require expensive equipment and experienced investigators. Transperineal ultrasound may represent another method of detecting perianal complications in Crohn's disease. We investigated Crohn's disease perianal and rectovaginal fistulae using transperineal ultrasound and compared the findings with results of endoanal ultrasound as reference standard.
A total of 46 patients with Crohn's disease and perianal and/or rectovaginal or anovulvar fistulae underwent, transperineal and endoanal ultrasound, on the same day. Transperineal ultrasound was performed using regular convex and high-resolution linear probes. Endoanal ultrasound was performed using an ultrasound system with a 7 MHz rotating endoanal probe. Fistulae were classified according to Parks' classification in intrasphincteric, transsphincteric, suprasphincteric, and extrasphincteric. Rectovaginal or anovulvar fistulae were described separately. Presence of abscesses was also reported.
Fifty-two fistulae (3 intra-sphincteric, 28 transsphincteric, 8 suprasphincteric, 2 extrasphincteric, 9 rectovaginal, and 2 anovulvar) were detected by transperineal ultrasound. Endoanal ultrasound confirmed the correct classification of 45 fistulae (predictive positive value: 86.5%). Of the 53 fistulae detected by endoanal ultrasound, 45 were correctly classified by transperineal ultrasound (sensitivity 84.9%). Transperineal ultrasound showed 10 perianal abscesses: 2 horseshoe, 4 deep, and 4 superficial. Endoanal ultrasound confirmed all horseshoe, 3 deep, and 2 superficial abscesses and did not find further abscesses.
Transperineal ultrasound is a simple, painless, real-time method to detect and classify perianal and rectovaginal fistulae and/or abscesses in Crohn's disease.
Chair of Gastroenterology, Department of Clinical Sciences, L. Sacco University Hospital, University of Milan, Italy
Reprint requests and correspondence: Giovanni Maconi, Chair of Gastroenterology, Department of Clinical Sciences, L.Sacco University Hospital, University of Milan, Via G.B. Grassi, 74, 20157 Milan, Italy.
CONFLICT OF INTEREST Guarantor of the article: The guarantors are Giovanni Maconi and Gabriele Bianchi Porro.
Specific author contributions: Giovanni Maconi, M.D.: Planned the study, performed the ultrasonographic exams, analyzed the data and wrote the manuscript. Sandro Ardizzone, M.D.: Performed the endoanal sonographic exams, helped in interpreting the data and wrote the manuscript. Salvatore Greco, M.D.: Collected the data, helped in interpreting the data and wrote the first draft of the manuscript. Elisa Radice, M.D.: Collected the data and wrote the first draft of the manuscript. Cristina Bezzio, M.D.: Collected the data, and wrote the first draft of the manuscript. Gabriele Bianchi Porro, M.D., Ph.D.: Co-Guarantor of the paper.
Financial support: None.
Potential competing interests: None.
Received January 7, 2007; accepted May 15, 2007.