Short Protocol Barostat for Assessment of Anorectal Function Versus Standard Protocol Barostat in Healthy Volunteers
Condition: Healthy
Study type: Interventional
Phase: Phase 4

Summary: 
      The aim of this monocentric, prospective, non randomised study with 25 healthy volunteers is
      to assess anorectal function ( i.e rectal compliance and sensory thresholds) in health with a
      short protocol barostat versus conventional procedures (i.e. standard barostat protocol and
      high resolution anorectal manometry). Anorectal dysfunction is a key mechanism in the
      development of fecal incontinence and symptoms of obstructive defecation.

      In this study volunteers will be examined - after explanation, physical examination and
      verification of in- and exclusion criteria - by anorectal barostat with short and standard
      protocol as well as by proctoscopy and endoanal ultrasound.
    

Detailed description: 
      For a coordinated anorectal function in addition to the anal sphincter the perception of
      rectal distension (visceral perception) and elasticity / compliance of the anorectum and
      stool consistency is important. A disturbed anorectal function may lead to functional
      defecation disorders or incontinence.

      The currently available methods for measuring physiological assessment of anorectal function
      mostly focus on measurement of sphincter pressures, but generally provide no complete
      explanation for the underlying pathophysiology of defecation disorders. By voluntary
      contraction of the striated muscles of the external anal sphincter and puborectalis muscle
      defecation can be further delayed. In addition, however, other continence mechanisms play an
      important role.

      The Group for the Study of functional gastrointestinal disorders at the Clinic for
      Gastroenterology at the University Hospital of Zurich has a great expertise in the
      establishment of new research methods such as the already in routine clinical practice used
      high-resolution anorectal manometry and has conducted numerous studies with anorectal
      Barostat. To use the results of Barostat also in everyday clinical practice in patients with
      defecation disorders this technique means significant simplification of the instrumental
      methodology and shortening of the work described in the literature. Before the simplified
      barostat can be used with the shortened protocol in different patient groups and clinical
      practice, it generally requires the validation of the technique in healthy subjects to define
      the range of normal values.
    

Intervention name(s): anorectal manometry; barostat
Intervention type(s): Device; Device
Intervention description(s): High-resolution anorectal manometry is done under standard clinical conditions with a 10 cm catheter inserted into the rectum loaded with pressure transducers at a distance of 6 mm in the sphincter area and an attached latex balloon at the catheter tip. It will measure the length of the anal sphincter, the static pressure and the clamping pressure during at least 3 over 40 seconds sustained maneuvers according to a standardized protocol. Mean and maximum pressure increase over the resting pressure during the first 30 seconds of the squeeze and the maximum possible squeeze time will be documented. Moreover, the initial anorectal perception threshold, the perception of urge to defecate and maximum tolerable volume balloon will be documented.; For the barostat study a balloon will be attached to the catheter. Instead of a barostat machine a 60ml syringe and a sphygmomanometer will be connected to the catheter and the catheter will be positioned in the rectum. The balloon is then dilated gradually to assess perception, urge and discomfort threshold in relation to rectal volume.
Other intervention name(s): AHRM
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic