Myocardial Ischemia Due to Kinking of Left Internal Mammary Artery Graft with the Expiratory Phase of Respiration

Coronary angiography showed 30% stenosis in the distal left main artery, 80% in-stent restenosis in the ostial CFX, and 60% in-stent restenosis of the ostial LAD. The tortuous LIMA graft to the LAD and the radial graft to the obtuse marginal branch were free of atherosclerotic disease, but a transient occlusion of the LIMA in mid-segment was observed during the expiratory phase of respiration (Figures 2 A and B). The patient’s symptoms and the reversible anterolateral defect observed on the functional study were felt to be secondary to the transient occlusion of the LIMA graft that occurred with expiration. He underwent stenting of the left main, ostial LAD and CFX coronary arteries, with relief of symptoms.

Discussion. This case illustrates that kinking of bypass grafts during the expiratory phase should be considered in the differential diagnosis of chest pain in patients who have undergone CABG. Ischemia due to kinking has been reported to occur as a rare phenomenon with both LIMA and saphenous vein grafts.^1,2 Percutaneous and surgical intervention has been attempted to relieve occlusion due to kinking in such cases.^2,3 Our patient showed marked symptomatic relief after placement of a stent in the native coronary circulation.

References

1. Diarte JA, Salazar JJ, Placer LJ. [Saphenous vein graft kinking: Angiographic image]. Rev Esp Cardiol 2001;54:997–998.
2. Rerkpattanapipat P, Ghassemi R, Ledley GS, et al. Use of stents to treat kinks causing obstruction in a left internal mammary artery graft. Catheter Cardiovasc Interv 1999;46:223–226.
3. Cetindag IB, Quin JA, Grasch AL, Hazelrigg SR. Thoracotomy for correction of a kinked right internal mammary artery graft. Ann Thorac Surg 2003;75:1655.