Effectiveness of a three-dimensional anorectal ultrasound in perianal Crohn's disease: incompatibility with clinical and surgical examinations.

Abstract

We have correlated the 3D anorectal ultrasound (3D ARU) findings with clinical examination and the surgical findings and examined its capacity to provide ancillary information, which potentially alters patient management. This is a prospective analysis conducted at a tertiary academic hospital. A total of 95 patients were included. We screened for sphincter defects and the presence of perianal Crohn's disease (PACD)-related lesions. We performed 150 3D ARUs. Exploratory ultrasound coincided with the rationale for diagnosis in 67.7% of cases, and fistulae were detected in 79% of cases where there was clinical suspicion. Fistulae were associated with abscesses in 29 cases, and isolated abscesses were identified in 19 cases (17.7%), only 12 of which (63.2%) were clinically suspected. Sphincter defects were observed in 15 cases with 7 cases (77.8%) presenting with clinical fecal incontinence. The operative findings coincided with ultrasonographic findings in 81.3% of the analyzed cases. The inter-observer variability of endosonographic classification resulted in a kappa score of 0.86. Ultrasonographic data altered the therapeutic plan of management in 73 cases (48.6%). Three-dimensional ARU is accurate in the diagnosis of fistula type in PACD and in the delineation of ancillary suspected and unsuspected abscess collections. Its use impacts therapeutic management in about half the cases examined. A new ultrasonographic-based PACD classification system is presented which has high inter-observer agreement but which requires future prospective validation in clinical PACD patients.