Non-invasive assessment of left internal mammary-coronary bypass patency using the external Doppler probe

Area of Science:

• Cardiovascular Surgery
• Medical Imaging
• Vascular Ultrasound

Background:

• Internal mammary artery (IMA) grafts are crucial for coronary artery bypass grafting (CABG).
• Assessing the long-term function and patency of IMA grafts is essential for patient outcomes.
• Non-invasive monitoring methods are needed to evaluate graft health efficiently.

Purpose of the Study:

• To evaluate the utility of Doppler ultrasound for assessing blood velocity in internal mammary artery bypass grafts.
• To determine if Doppler signals can differentiate between patent and occluded IMA grafts.
• To explore the potential of this technique for ambulatory and in-office screening of graft function.

Main Methods:

• Non-directional Doppler ultrasound probe used to study blood velocity.
• Subjects included patients with left internal mammary bypass grafts.
• Angiography used to confirm graft patency in most subjects.

Main Results:

• Doppler signals showed high amplitude phasic blood velocities in 13 of 14 patent grafts.
• A single patient with proximal graft occlusion exhibited significantly attenuated Doppler signals.
• The technique demonstrated sensitivity to changes in graft blood flow.

Conclusions:

• Doppler ultrasound is a promising non-invasive method for evaluating internal mammary artery bypass graft function.
• This technique can effectively identify patent grafts and detect occlusions.
• The method holds potential for convenient, in-office screening of IMA graft patency.