Fistula in Ano Role of Transperineal and Transvaginal Sonography

An accurate delineation of the surgical anatomy of perianal inflammatory disease is vital before surgery to prevent postoperative recurrence and incontinence. The purpose of this study was to evaluate the use of transperineal sonography for evaluating perianal inflammatory disease. Thirty patients (23 males and 7 females) with clinically suspected perianal inflammatory disease were imaged with transperineal sonography in males and transperineal and transvaginal sonography in females. All fluid collections, sinus tracts, and fistulae were evaluated in relation to the sphincters and perineum. Twenty-seven of the 30 patients had fistulae: 7 intersphincteric, 17 transphincteric, and 1 extrasphincteric fistula. Three patients had perianal fluid collections with sinus tracts. Preoperative sonographic findings were confirmed in 23 patients. Thirty-one internal openings seen on sonography were confirmed on surgery. The authors conclude that transperineal and transvaginal sonography are accurate and painless methods for documenting perianal inflammatory disease.