Late spontaneous internal thoracic artery graft dissection after coronary bypass grafting: a case report

BACKGROUND: Internal thoracic artery (ITA) grafts are commonly used for coronary artery bypass grafting, with dissection to the graft being a rare occurrence. Herein, we describe a case of spontaneous ITA graft dissection occurring 11 years after grafting, with no clear precipitating incidence. CASE SUMMARY: The patient was a 61-year-old man who presented with a 3-month history of chest pain and dyspnoea. Dissection of the left internal thoracic artery (LITA) graft was observed on angiography, with a thrombolysis in the myocardial infarction (TIMI) grade 2 blood flow. Intravascular ultrasound confirmed an intimal tear in the proximal graft, with an intramural haematoma. In the absence of atherosclerotic changes, the dissection was treated directly using multiple drug-eluting stents to prevent further extension of the intramural haematoma proximally into the subclavian artery and distally to the anastomosis site. Post-procedural angiography revealed an enlarged true lumen of the LITA, shrinking of the intramural haematoma, and improvement in blood flow to a TIMI grade 3. Chest symptoms resolved immediately after the procedure, with the patient remaining asymptomatic over the 6-month period following the procedure. DISCUSSION: Dissection of the ITA graft can occur spontaneously long after the initial grafting. Intravascular ultrasound is useful for diagnosis. Ensuring adequate coverage of the edges of the dissection with stenting could prevent further extension of the intramural haematoma.