Objectives: To characterize the clinical and angiographic characteristics of patients with collateralization from the internal mammary artery to the iliac artery.
Background: The use of the internal mammary arteries for coronary revascularization has become the standard of care in coronary artery bypass grafting (CABG). However, in patients with aortoiliac disease, the internal mammary arteries may become a major collateral route to the lower extremities.
Methods: A case series of 15 patients admitted for diagnostic coronary angiography were retrospectively identified, who were observed to have collateral flow from one or both internal mammary artery(ies) to an occluded or stenotic iliac artery.
Results: The mean age was 63.2 +/- 11.2 years; eight were men (53.3%). Coronary angiography was done as a perioperative evaluation for peripheral vascular surgery in three patients (20%) and was done because of cardiac symptoms or a positive thallium scan in 12 (80%). The finding that the mammary artery collateralized the iliac artery led to major treatment changes in all patients, seven (46.6%) who required CABG. In five patients (33%), use of one or both internal mammary artery(ies) for coronary grafts was avoided. CABG was deferred in one patient, whereas in another, percutaneous intervention in both iliac arteries preceded CABG using both mammary arteries. There was no incidence of postoperative acute lower extremity ischemia.
Conclusions: Selective angiographic visualization of the internal mammary artery is an essential part of the preoperative evaluation in patients with severe peripheral vascular disease undergoing CABG.