Aneurysm sac pressure monitoring: effect of pulsatile motion of the pressure sensor on the interpretation of measurements.

Purpose:To determine the effect of pulsatile motion of graft-attached pressure sensors on the accuracy of aneurysm sac pressure measurement.Methods:Pressure inside a pressure box was measured with a sensor attached to a stent-graft (Sensorgraft) facing a sensor in fixed position (Sensorbox). Maximum inter-sensor variation of Sensorgraft and Sensorbox was determined in static experiments. Experiments with pulsatile circulation were performed with a compliant and a noncompliant stent-graft at 120/80 mmHg and 160/95 mmHg. Pressure measurements in the box were repeated after the box pressure was increased from 0 to 120 mmHg. Sensorgraft motion was measured by ultrasound. Measurements with Sensorgraft were compared to those with Sensorbox using Pearson correlation coefficients to determine the concordance between the sensors.Results:The maximum inter-sensor variation was 4 mmHg. Increased box pressure induced progressive pulsatile graft and sensor motion during all experiments. During the experiments with the ...