Manometry of canine ileocolonic sphincter: Comparison of sleeve method to point sensors

Tonic and phasic pressures at the canine ileocolonic sphincter (ICS) were recorded by a manometric assembly that combined a sleeve sensor with multiple side-hole pressure ports. By aligning the side holes precisely it was possible to evaluate in vivo the fidelity of the sleeve relative to simultaneous pressure records from the point sensors. The ICS exhibited tonic and phasic pressures, often in excess of 100 cmH₂O of pressure. The sleeve sensor was tolerant of small, but potentially important, movements of the assembly relative to the ICS. Point sites of recording moved in and out of the high-pressure zone and side holes were, therefore, not ideal sensors of sphincteric tone. The anticipated properties of this sleeve, that it would display reduced fidelity for rapid changes in pressure at sites away from its point of perfusion, were confirmed in vivo. The sleeve also 'summarized' phasic bursts and was unable to monitor propagation of such events. However, the combined assembly proved excellent for examining overall function of the canine ICS.