The use of intra-operative endo-anal ultrasound in perianal disease.

Introduction: Endoanal ultrasound (EAUS) has demonstrated high sensitivity and specificity for the structural imaging of anorectal pathology. This study prospectively assessed the impact of intra-operative EAUS on the surgical management of perianal disease.

Methods: EAUS was performed prior to and after examination under anaesthesia (EUA) in a consecutive series of patients with perianal disease. The impact of EAUS on the surgery performed was identified.

Results: Forty-three procedures have been performed in 38 patients (21 male, 17 female; mean age 42.7 years, range 6-76 years) over a three year period. Pathologies encountered were fistula-in-ano (42%), fissure-in-ano (26%), complicated perianal sepsis (16%) and carcinoma (5%). No specific abnormality was identified in 5 symptomatic patients (12%). Four patients with fissures had undergone previous sphincterotomy. In 22 cases (51.2%) the EAUS findings affected the surgical management (extent of muscle above a fistula 9 cases, extent of sphincterotomy 7 cases, site of sepsis identified 2 cases, exclusion of sepsis 2 cases, assessment of cancer resectability 1 case, biopsy of intersphincteric lesion 1 case).

Conclusion: Intra-operative EAUS accurately identifies perianal disease and influences the surgical procedure performed. While not essential, it is a useful adjunct especially in recurrent perianal sepsis, undiagnosed anorectal pain and anal fissure.