Three‐dimensional high‐resolution anorectal manometry: does it allow automated analysis of sphincter defects?

AIM: Anorectal manometry is the most common test used to explore anorectal disorders. The recent three-dimensional high-resolution anorectal manometry (3D-HRAM) technique appears to be able to provide new topographic information. Our objective was to develop an automated analysis of 3D-HRAM images to diagnose anal sphincter defects and compare the results with those of endoanal ultrasonography (EUS), which is considered to be the gold standard. METHOD: All patients being tested in our department for faecal incontinence or dyschezia by 3D-HRAM and EUS were eligible for the study. 3D-HRAM was used to record resting and squeeze pressure, reflecting internal and external anal sphincter function, respectively. A software platform was designed to automatically analyse the 3D-HRAM images and calculate a diagnostic score for any anal sphincter defect compared with EUS. RESULTS: A total of 206 (91% female) patients of mean age of 54 years were included in the study. A sphincter defect was diagnosed by EUS in 130 (63%). The diagnostic scores from the 3D-HRAM automated analysis for an internal anal sphincter defect showed a sensitivity of 65% and a specificity of 65%. For an external anal sphincter defect, the sensitivity was 43% and the specificity 87%. CONCLUSION: Our study developed a method based on 3D-HRAM to automatically diagnose sphincter defects, allowing a systematic and comprehensive analysis of the test recordings. Compared with EUS, the 3D-HRAM image analysis procedure revealed poor sensitivity and specificity.