title: Use of vector volume manometry and endoanal magnetic resonance imaging in the adult female for assessment of anal sphincter dysfunction.
abstract: OBJECTIVE
  This study compared conventional water-perfused and vector volume anal manometry in female patients with neurogenic fecal incontinence and chronic anal fissure and in healthy female volunteers. We used endoanal magnetic resonance (MR) imaging to measure internal and external sphincter lengths and thicknesses and contrasted these with the manometric findings in the different anorectal conditions.
  
  
  METHODS
  One hundred thirty-three female subjects were studied over an eight-month period, including 33 control volunteers, 83 patients with neurogenic fecal incontinence, and 17 patients with chronic anal fissure. Conventional manometry was contrasted with automated vector volume-derived parameters. Endoanal magnetic resonance images were obtained using a previously described internal coil with a 0.5 T Asset scanner measuring quadrantal internal sphincter thickness and averaged coronal internal and external sphincter lengths.
  
  
  RESULTS
  There was a statistically significant relationship between parameters measured by conventional manometry and those variables derived from vector volume manometry at rest and squeeze. There was no difference in sectorial vector-derived pressures within any anorectal condition and no correlation between quadrantal internal sphincter thickness measurements and sectorial pressures at rest. Patients with chronic anal fissure and neurogenic fecal incontinence had constitutionally shorter superficial and subcutaneous external sphincters than healthy control subjects (P < 0.001).
  
  
  CONCLUSIONS
  There is no association between manometric findings and morphologic sphincter measurement; however, the shorter distal external sphincter in patients with fissure might render the lower anal canal relatively unsupported after internal sphincterotomy in the female patient.
authors.affiliation: Academic Department of Colorectal Surgery, Imperial College School of Science, Technology, and Medicine, London, United Kingdom.
authors.forename: A P
authors.initials: AP
authors.lastname: Zbar
authors.forename: W A
authors.initials: WA
authors.lastname: Kmiot
authors.forename: M
authors.initials: M
authors.lastname: Aslam
authors.forename: A
authors.initials: A
authors.lastname: Williams
authors.forename: A
authors.initials: A
authors.lastname: Hider
authors.forename: R A
authors.initials: RA
authors.lastname: Audisio
authors.forename: A
authors.initials: A
authors.lastname: Chiappa
authors.forename: N
authors.initials: N
authors.lastname: deSouza
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001003:Anal Canal / Q000294:innervation / Q000473:pathology / Q000503:physiopathology*; D002908:Chronic Disease; D003113:Colonoscopy; D005242:Fecal Incontinence / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D005401:Fissure in Ano / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008365:Manometry / Q000379:methods; D008875:Middle Aged; D011312:Pressure; D012720:Severity of Illness Index