Noninvasive intraoperative assessment of arterial reconstruction. Experimental validation of the role of central and regional hemodynamics
R. P. Cambria, R. Walden, J. Megerman, G. L'Italien and W. M. Abbott
We developed an experimental model of graded arterial stenosis to emulate
conditions that might be encountered immediately following arterial
grafting. Noninvasive measurements of systolic BP and limb blood flow were
recorded with a Doppler probe and segmental air plethysmography,
respectively, under conditions of different cardiac output and local
arterial resistance. These measurements were correlated with direct
intra-arterial pressure recordings and flow measurements taken with an
electromagnetic flowmeter. There was an excellent correlation between
noninvasive and intra-arterial measurements of systolic pressure over a
range of cardiac outputs and degree of arterial stenosis. Pulse volume
recordings correlated with direct measurements of blood flow at high and
baseline cardiac outputs, but the calibration of pulse volume amplitude
varied between cuff applications in this canine model. Noninvasive
intraoperative monitoring techniques can faithfully represent known
physiologic responses to graded arterial stenoses, irrespective of a high
cardiac output or peripheral vasodilation.
