Clinical assessment

Clinical assessment

A full medical (including obstetric, gastrointestinal, anal surgical and continence) history and proctosigmoidoscopy are necessary to gain information about sphincter strength and to exclude associated conditions. The key points to determine by clinical assessment of the fistula involve the following essential points: /uni25CF the site of the internal opening; /uni25CF the site of the external opening(s); /uni25CF the course of the primary track; /uni25CF the presence of secondary extensions; and /uni25CF the presence of other conditions complicating the fistula. Palpable induration between the external opening and the anal margin suggests a relatively superficial track, whereas supralevator induration suggests a primary track above the levators or high in the r oof of the ischiorectal fossa, or a high secondary extension. Intersphincteric fistulae usually have an external opening close to the anal verge. Goodsall’s rule ( Figure 80.30 ), used to indicate the likely position of the inter nal opening according to the position of the external open ing(s), is helpful; however, the majority of internal openings are midline in both the anterior and posterior planes. The site of the internal opening may be felt as a point of induration or seen as an enlarged papilla. Dilute hydrogen pero xide, instilled via the external opening, can demonstrate the site of the internal opening ( Figure 80.31 ); gentle use of probes ( Figure 80.32 and a finger in the anorectum usually delineates primary and secondary tracks and their relations to the sphincters. Any concerns about fistula topography at clinical examination or examination under anaesthesia (more common after previous unsuccessful surgery) should prompt further investigations before surgical intervention. David Henry Goodsall , 1843–1906, surgeon, St Mark’s Hospital, London, UK. - - - - )

Anterior Figure 80.30 Goodsall’s rule. Figure 80.31 Injection of dilute hydrogen peroxide through the exter

nal /f_i stula opening identi /f_i es the position of the internal opening at the dentate line. Figure 80.32 Retrograde probing of an anal canal sometimes reveals the internal ori /f_i ce of the /f_i stula.