title: The importance of anal endosonography in the evaluation of idiopathic fecal incontinence.
abstract: OBJECTIVE
  The aim of the study was to evaluate the use of anal endosonography in idiopathic incontinence.
  
  
  METHODS
  In 29 patients and 26 normal controls, the relationship between sonography images and physiologic parameters was studied.
  
  
  RESULTS
  External anal sphincter function, measured as fiber density by single-fiber electromyography (P = 0.0001) and pudendal nerve terminal motor latency (P = 0.04), was significantly impaired in patients with idiopathic incontinence compared with controls. Both the external and internal and sphincter could be identified by anal endosonography, and the thickness directly measured. The thickness of the external anal sphincter was significantly negatively correlated to muscle fiber density (r = -0.65, P = 0.002) and to pudendal nerve distal conduction velocity (r = -0.74, P = 0.008). The thickness of the internal anal sphincter was significantly correlated to resting pressure (r = -0.67, P = 0.0001).
  
  
  CONCLUSIONS
  The ratio between the thickness of the external and internal sphincter muscles measured on the sonography screen was significantly reduced in patients with neurogenic incontinence compared with controls (P < 0.01).
authors.affiliation: Department of Surgery, National Hospital, University of Oslo, Norway.
authors.forename: R
authors.initials: R
authors.lastname: Emblem
authors.forename: G
authors.initials: G
authors.lastname: Dhaenens
authors.forename: R
authors.initials: R
authors.lastname: Stien
authors.forename: L
authors.initials: L
authors.lastname: Mørkrid
authors.forename: A O
authors.initials: AO
authors.lastname: Aasen
authors.forename: A
authors.initials: A
authors.lastname: Bergan
mesh_terms: D000328:Adult; D000368:Aged; D001003:Anal Canal / Q000000981:diagnostic imaging* / Q000294:innervation / Q000503:physiopathology; D000704:Analysis of Variance; D004576:Electromyography; D005242:Fecal Incontinence / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009469:Neuromuscular Junction / Q000503:physiopathology; D011312:Pressure; D014463:Ultrasonography