Hiding intersphincteric and transphincteric sepsis in a novel pathological approach to chronic anal fissure

The purpose of this study was to investigate whether endoanal ultrasonographic findings could better characterize chronic anal fissures, mostly in those patients with persistent and recurrent disease after medical treatment.

Between January 2004 and April 2010, patients referred to our departments suspected for anal fissure were considered in a database. Physical examination and anoscopy confirmed the diagnosis of anal fissure in 543 patients. Chronicity was defined on the basis of morphological features of the fissure and mainly on its persistence or recurrence after medical therapy. Moreover, 172 out of 543 patients were selected with respect to the inclusion criteria and submitted to endoanal ultrasonography.

Seventeen out of 172 were anterior fissures (9.8%) and 155 posterior (90.2%). In 112 (65.1%) out of 172 patients submitted to endoanal ultrasonography, an associated chronic abscess was demonstrated, with expression of 91 intersphincteric and 21 low transphincteric fistulas, respectively. According to clinical data as well as comorbidities and previous surgery, there were no significant differences between patients with associated abscess and those with only chronic anal fissure.

The authors assume that chronic fissures may persist because of hiding sepsis in the anal canal and that chronic anal fissure might be the clinical and pathological expression of a coexisting intersphincteric or low transphincteric fistula, and the ultrasonographic findings strongly support this theory.