Seated Evaluation of Anorectal funcTion by High Resolution Anorectal Manometry
Condition: Anismus; Incontinence
Study type: Interventional

Summary: 
      To assess whether HR-ARM (High resolution Anorectal Manometry) performed in the more
      naturalistic / physiological upright, seated position on a commode provides a more valid
      assessment of anorectal function and simulated defecation than the same test performed in the
      standard, left lateral position
    

Detailed description: 
      High Resolution Anorectal Manometry (HR-ARM) with data presented as pressure topography is a
      recent addition to the tests available for diagnosis of defecatory disorders including fecal
      incontinence and constipation.HR-ARM represents an advance on conventional manometry because
      closely spaced sensors across the anal sphincter remove the need for a pull-through procedure
      and facilitate data acquisition and interpretation. In particular measurements are not
      confounded by changes in position of the catheter relative to anal sphincter that occur
      during voluntary contraction and, especially, simulated defecation.

      Notwithstanding these technological improvements, important concerns remain about the
      validity of manometry measurements during simulated defecation. These concerns are based on
      the observation in both conventional and HR-ARM that a large proportion of healthy
      individuals appear to have abnormal anorectal function ("dyssynergia") during simulated
      defecation.This limitation led to the recommendation that the finding of dyssynergia on
      manometry should be confirmed by defecography. This is unsatisfactory as diagnostic tests
      should not have a high rate of "false positives" and also because this increases the time and
      costs needed to complete diagnostic investigation in patients with defecatory disorders.

      The high rate of abnormal findings in healthy individuals may be because current manometry
      procedures and other anorectal tests (e.g. rectal balloon expulsion) are usually performed,
      not in the upright, seated position (USP) usually adopted for defecation, but in the
      un-physiological left lateral position (LLP). Several factors may contribute. First,
      defecation in the LLP is not aided by gravity as it is in the sitting position. Second,
      anorectal anatomy may be altered and less conducive to the passage of stool in the LLP.
      Third, simulating defecation in the LLP does not reflect normal behavior and, despite optimal
      interaction and explanation by the investigator, changes in patient behavior may result in
      apparent "dyssynergia" Finally, social stress, related to proximity of the investigator
      observing defecation, makes individuals feel unable to strain at stool or attempt defecation.

      A simple probe holder device that, by adhering to the skin is positioned at the natal cleft
      to support the ManoScan HR ARM catheter can be used to assess anorectal pressures in the
      sitting position (both produced by Given Imaging, Yoqeam, Israel). This simple device
      stabilizes the catheter position when the patient is in USP on a commode and allows the
      investigator to withdraw behind the curtains of the examination cubicle.
    

Intervention name(s): HRARM; MRI Defecography
Intervention type(s): Other; Other
Intervention description(s): Patients and healthy volunteers are investigated in the seated and lying position during HRAM; Patients and healthy volunteers are investigated in the supine and left lateral position in the MRI
Other intervention name(s): MRD
Allocation: Non-Randomized
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic
Keywords: High Resolution Anorectal Manometry; Magnetic Resonance Imaging; Balloon Expulsion; Position