Combowire for Intravascular Surgery
BME 240: Applications in Clinical Medicine
Emerging Applications
1. Coronary Vasculature



Sample data generated by advancing a guide wire past a lesion site and simultaneously recording cyclical pressure proximal and distal to the site. Proximal pressure is often well correlated with aortic pressure and can be measured at the tip of the catheter in the aortic arch prior to entrance into the ostia. The graph below is from a ComboWire recording showing the advantage of having a velocity recording as well as the parallel calculation of ∆P by the system. Induction of hyperemia coincides with the increase in velocity and a drop in distal pressure (arrows).

2. Renal Vasculature


An angiogram of the right renal artery is displayed on the left side of the screen prior to and post angioplasty procedure. While the images on the left can only provide qualitative information of the underlying stenosis, the wire measurements on the right provide a tremendous advantage by quantifying FFR prior (0.71) and post (1.00) treatment. Additionally, with the advent of dual pressure-velocity sensor wires, HSR can be calculated for patients with renal artery stenosis. This would give an even more accurate picture of hemodynamic effect of the underlying pathology.  

3. Abdominal Vasculature



Abdominal angiogram of the right iliac artery reveals eccentric stenosis of unknown severity. Pressure wire tracings, however, reveal a 10 mmHg gradient at rest and 20 mmHg during hyperemic runs. This gives another good example of the necessity of hemodynamic data as well as potential future consideration for HSR calculation via ComboWire.

4. Measurement of Valveolar Gradients


The extremely small diameter of current guide wires (0.36 mm) allows their use in a wide range of clinical applications including assessment of heart valves like the mechanical aortic heart valve shown here. The gradient was calculated by subtracting the ventricular pressure, measured by pressure wire inside the left ventricle, minus the aortic pressure, measured by fluid-filled catheter in the aorta. The echocardiography measurement of 48 mmHg was shown to be inaccurate by direct pressure wire measurement of 24 mmHg gradient.