THE IMPORTANCE OF ANAL ENDOSONOGRAPHY IN THE EVALUATION OF IDIOPATHICFECAL INCONTINENCE

PURPOSE: The aim of the study was to evaluate the use of anal endosono graphy in idiopathic incontinence. METHODS: In 29 patients and 26 norm al controls, the relationship between sonography images and physiologi c parameters was studied. RESULTS: External anal sphincter function, m easured as fiber density by single-fiber electromyography (P = 0.0001) and pudendal nerve terminal motor latency (P = 0.04), was significant ly impaired in patients with idiopathic incontinence compared with con trols. Both the external and internal anal sphincter could be identifi ed by anal endosonography, and the thickness directly measured. The th ickness of the external anal sphincter was significantly negatively co rrelated to muscle fiber density (r = -0.65, P = 0.0002) and to pudend al nerve distal conduction velocity (r = -0.74, P = 0.008). The thickn ess of the internal anal sphincter was significantly correlated to res ting pressure (r = -0.67, P = 0.0001). CONCLUSION: The ratio between t he thickness of the external and internal sphincter muscles measured o n the sonography screen was significantly reduced in patients with neu rogenic incontinence compared with controls (P < 0.01).