Can We always Use the Internal Thoracic Artery in Bypass Grafting? A Word of Caution

Introduction: Arterial revascularization should be the standard surgical care in bypass surgery. However, there are some specific small group of patients with interesting aberrations of the normal perfusion anatomy which require careful planning and possible modification of the otherwise standardized procedure.

Background: This case reports on an unusual anomaly observed while harvesting of the internal thoracic artery for coronary bypass grafting. The arterial graft was massively enlarged with a diameter >8mm and the operating surgeon was hesitant to use the artery for grafting of the LAD. This hesitation can be explained by the past experience of this surgeon with a similar patient showing subsequent diagnosis of coarctation of the aorta. Use of the arterial graft unfortunately led to paraplegia of this patient. Venous bypass surgery was performed on the elderly patient and an uneventful postoperative course could be achieved. Consecutive CT angiography demonstrated an occlusion of the celiac trunk and superior mesenteric artery with a collateral perfusion via the left internal thoracic and epigastric artery. Retrograde perfusion was demonstrated to the over 7mm occluded celiac trunk as well as the mesenteric artery.

Discussion: In this case use of the left internal thoracic artery with distal closure of the artery would have created problems with subsequent malperfusion of the abdomen. Preoperative diagnostics with visualization of the internal thoracic artery during coronary angiography or CT angiography would have demonstrated the collateral network of the visceral organs over the artery, however these problems are so seldom that a systematic checkup of the visceral perfusion may be uncalled for. Utmost care should however be taken during harvesting. Coarctation of the aorta or occlusive mesenteric vessels may be the reason for gross enlargement of the internal thoracic artery and should be considered.