Abstract

Quadruple, patent coronary artery bypass grafts

posted by Pal Suranyi, M.D., PhD | Jul 4, 2008

Case history
Five years following quadruple CABG surgery, this 64-year-old patient started experiencing atypical chest pain.

Question
Are any of the bypass grafts or anastomoses stenotic or occluded? Is there an extra-cardiac cause behind the patient‘s symptoms?

Diagnosis/Differential diagnosis
Acute graft thrombosis, myocardial infarction, myocardial ischemia due to graft stenosis, aortic dissection, pulmonary embolism, pericarditis, lung tumor.

Findings
Although all four grafts appeared patent, there was a mild stenosis at the proximal anastomosis of one of the venous grafts (to the first obtuse marginal branch (OM1) of the LCx) with atretic distal runoff. In the posterolateral region, supplied by this vessel, myocardial hypoattenuation was found, suggesting ischemia (see figure).

Comment
Dual Source Cardiac CT can detect graft stenosis or tight anastomoses and consequent myocardial ischemia efficiently. The data can be used to plan intervention (stent size, approachability) or redo surgery if it is deemed necessary by the clinician.

[1] 3D overview of vascular anatomy. The origin of the LIMA from the subclavian artery can be assessed, as well as the proximity of this graft to the sternum.	[2] After carefully “removing” the chest wall, the configuration of this complicated anatomy can be easily reviewed. All four bypass grafts appear patent.
[3] Curved MPR of the vein graft to the OM1, showing a slight ostial stenosis and an atretic runoff. The myocardium supplied by this vessel appears hypoattenuating.	[4] Curved MPR of theLIMA, originating from the subclavian artery, and anastomosing with the LAD with satisfactory runoff. Note the surgical clips along the LIMA.