title: Biomechanical wall properties of the porcine rectum: a study using impedance planimetry.
abstract: The aim was to investigate biomechanical wall properties of the porcine rectum by way of manometry and impedance planimetry. Distension of a balloon inserted into the rectum with definite pressure steps up to 80 cm H2O was done for simultaneous recording of pressure and the balloon cross-sectional area (Bcsa). Viscoelastic wall properties were derived in terms of compliance. Besides eliciting the ascending peristaltic reflex and relaxation of the internal anal sphincter, the balloon inflation elicited a phase of rapid Bcsa increase followed by an accommodation phase of slow Bcsa increase to a steady-state Bcsa, reached within 3 min. The Bcsa increased in a nonlinear way with increasing balloon pressures with only a minimal increase from 70 to 80 cm H2O. Rectal compliance decreased in a nonlinear way with increasing distension pressure.
authors.affiliation: Institute of Experimental Clinical Research, University of Aarhus, Denmark.
authors.forename: F H
authors.initials: FH
authors.lastname: Dall
authors.forename: C S
authors.initials: CS
authors.lastname: Jørgensen
authors.forename: J C
authors.initials: JC
authors.lastname: Djurhuus
authors.forename: H
authors.initials: H
authors.lastname: Gregersen
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D003672:Defecation / Q000502:physiology; D005260:Female; D005769:Gastrointestinal Motility / Q000502:physiology*; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D009126:Muscle Relaxation / Q000502:physiology; D009130:Muscle, Smooth / Q000502:physiology*; D011312:Pressure; D012007:Rectum / Q000502:physiology; D012018:Reflex / Q000502:physiology; D013552:Swine