title: Measurement of anal cross-sectional area and pressure during anal distension in healthy volunteers.
abstract: A probe for simultaneous measurement of cross-sectional area and pressure was used to elucidate biomechanical wall properties during anal distension. Measurements in distal sphincter regions demonstrated a high resistance to stretch and a large hysteresis compared to proximal sphincter regions. Resistance to stretch decreased during anal distension indicating an active relaxation mechanism at all recording levels. The zone with high resistance to stretch was located more distal than the high-pressure zone measured by anal-pressure profilometry. In conclusion, biomechanical wall properties of the anal canal cannot be described by classic viscoelastic theories but rather by a loss of sphincter tone caused by reflex mechanism during anal distension.
authors.affiliation: Institute of Experimental Clinical Research, University of Aarhus, Denmark.
authors.forename: H
authors.initials: H
authors.lastname: Gregersen
authors.forename: S
authors.initials: S
authors.lastname: Sørensen
authors.forename: S M
authors.initials: SM
authors.lastname: Sørensen
authors.forename: S
authors.initials: S
authors.lastname: Rittig
authors.forename: A J
authors.initials: AJ
authors.lastname: Andersen
mesh_terms: D000328:Adult; D001003:Anal Canal / Q000033:anatomy & histology / Q000502:physiology*; D001696:Biomechanical Phenomena; D002404:Catheterization; D003672:Defecation / Q000502:physiology; D005260:Female; D006801:Humans; D011312:Pressure; D014160:Transducers, Pressure