Graft Compression by Drain Tube.

Hemodynamic compromise immediately after chest closure can be potentially fatal event. Such condition warrants urgent reopening of sternum. In the present case, we discover An uncommon cause of unstable hemodynamics.

INTRODUCTION

Midline sternotomy for coronary artery bypass grafting surgery is the standard approach. Mediastinal chest drain tubes are generally placed through the subcostal incision for postoperative drainage of collection. Sudden fall in systemic arterial pressure after chest closure can be due to increased intrathoracic pressure with positive pressure ventilation or sudden collection of blood causing tamponade effect.

CASE REPORT

A 57-year-old gentleman presented with shortness of breath since 1 month on mild to moderate exertion. He was evaluated thoroughly and coronary angiography revealed triple vessel coronary artery disease. He was scheduled for coronary artery bypass grafting surgery. After midline sternotomy, off-pump three coronary vessels bypass grafting was performed – left internal mammary artery to left anterior descending coronary artery, two saphenous vein grafts to obtuse marginal artery and posterior descending artery.

Intraoperatively, hemodynamics were stable during grafting. Two mediastinal drain tubes were placed. After ensuring adequate hemostasis, sternum was closed by approximating sternal wires. As the skin was being closed, blood pressure started dropping. Trendelenburg position and fluid bolus were given. Escalating doses of inotropic infusions were started. Central venous pressure started rising and inferior leads ST elevation was observed. Hemodynamics were deteriorating so, immediately sternum was reopened. There was no obvious collection observed, however, saphenous venous graft to posterior descending artery appeared bluish in discoloration. One mediastinal drain was seen compressing the graft. Drain tube was removed from that position. Other grafts seemed to be normally functioning. After few moments, hemodynamics became stabilized and inotropic infusions were weaned. The patient was stable after chest closure.

DISCUSSION

Sternal closure can result in a significant restriction in diastolic filling and reduction cardiac output despite good cardiac function.[1] These effects are amplified by poor ventricular compliance due to myocardial edema and ischemia-reperfusion injury.[2] Furnary et al. have shown that opening sternum raises systemic blood pressure by 18% and cardiac index by 59% and thereby beneficial in improving low cardiac output.[3]

Graft compression by chest drain tube is a very unusual complication. It was effectively managed by the immediate reopening of the sternum. To the best of our knowledge, such rare complication has not been reported in the literature. Optimal positioning of drain tube in relation with bypass coronary graft should always be considered.

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Conflicts of interest

There are no conflicts of interest.