Arteriovenous shunt status post-coronary artery bypass graft surgery treated with microcoil placement: A case report

Abstract

Accidental cardiac arteriovenous (AV) anastomoses is a rare but severe complication of coronary artery bypass grafting. This can result in high output heart failure if left untreated. Little research has been done on the mainstays of treatment for this condition. Our patient is an 82-year-old male with a history of known coronary artery disease, status post-coronary bypass grafting surgery, presented with increasing shortness of breath, which was initially determined clinically to be due to high output heart failure, which was later confirmed during cardiac catheterization procedure. Coronary cardiac catheterization was carried out 2 weeks prior at an outside hospital for which the graft, which is supposed to be anastomosed of the circumflex, inadvertently anastomosed to the coronary sinus. The patient returned to the cardiac catheter lab and repeat angiography was performed. The left to right shunt was subsequently embolized using microcoils. He tolerated the procedure well. No recurrent anginal and/or heart failure symptoms were present. Interventional cardiology began the procedure by gaining right common femoral access. Next the saphenous vein graft to the coronary sinus was engaged with a 6 French JRy (Medtronic Inc., Minneapolis, MN) guide catheter and a 0.014” coronary wire was placed into the graft. Then interventional radiology advanced a 2.4 French microcatheter (Terumo, Ann Arbor, MI USA) over the 0.014” wire (Abbott Vascular Devices, Plymouth MN) into the mid to distal aspect of the bypass graft. Four detachable 0.018” microcoils (Terumo, Ann Arbor, MI USA) were carefully placed within the bypass graft. Subsequent angiogram demonstrated complete occlusion of the bypass graft with resolution of the AV shunt. Due to the acuity of the patient’s symptoms and the long timeframe from originally attempting stenting, no additional attempts to stent the circumflex were performed. Follow-up angiogram through the base catheter demonstrates complete occlusion of the bypass graft with resolution of the AV shunt. No contrast was seen entering the coronary sinus. The patient tolerated the procedure well with no immediate complications. Estimated blood loss was <10 mL. The patient was admitted overnight for further evaluation. No shortness of breath noted. He was discharged in good condition the following day. Accidental cardiac AV anastomosis is a rare complication of coronary artery bypass grafting that could lead to high output heart failure. In such cases, catheter directed embolization with microcoils can be done to occlude the AV shunt created by the previously placed cardiac catheter with resolution of heart failure symptoms.