LIMA-Left internal mamary artery is the most common arterial graft used in CABG.It is anastomosed with LAD /and or diagonal artery. Routine visualisation of LIMA is advocated by many , but it is required only in patients with critical CAD.
LIMA angiogram is done
- To confirm the presence of LIMA .
- To exclude subclavian stenosis.(If present hand can steal blood from heart !)
- To rule out disease of LIMA (Which is unlikely )
- Diameter of LIMA should be matched with LAD .LIMA with large lumens can accelerate restenosis in LAD due excess flow induced endothelial reaction
- To identify any early branching of LIMA .This can divert the blood flow and underperfuse LAD.
- Terminal bifurcation of LIMA can some times be used as a sequential graft to LAD/LCX/OM
- Tortuosity and looping of LIMA is common but generally has no hemodynamic significance.
- LIMA may provide vital nutritional support to sternum through direct or intercostal branches .If LIMA dependent sternal blood supply is found to be significant , sufficient precautions to be taken and anticipate sternal ischemia related complications.This is especially important in diabetic subjects.