Physiologic Functional Evaluation of Left Internal Mammary Artery Graft to Left Anterior Descending Coronary Artery Steal due to Unligated First Thoracic Branch in a Case of Refractory Angina.

Fadi J Sawaya,Henry Liberman,Chandan Devireddy

doi:10.1155/2016/3175798

Abstract

Unligated side branches of the left internal mammary artery (LIMA) have been described in the literature as a cause of coronary steal resulting in angina. Despite a number of studies reporting successful side branch embolization to relieve symptoms, this phenomenon remains controversial. Hemodynamic evidence of coronary steal using angiographic and intravascular Doppler techniques has been supported by some and rejected by others. In this case study using an intracoronary Doppler wire with adenosine, we demonstrate that a trial occlusion of the LIMA thoracic side branch with selective balloon inflation can confirm physiologic significant steal and whether coil embolization of the side branch is indicated.

Highlights

The internal mammary artery is the graft of choice in coronary artery bypass (CABG) surgery given its favorable longterm 90% patency at 10 years compared to saphenous vein grafts (SVG) [1, 2]
We report here a case of refractory angina in a patient with history of CABG surgery where we physiologically demonstrate coronary steal via a large unligated thoracic side branch by measuring coronary flow reserve before and after selective thoracic side branch balloon occlusion and successful treatment by coil embolization of the branch
Large unligated thoracic branches have been documented to occur in 10 to 20% of Left internal mammary artery (LIMA) grafts

Summary

Introduction

The internal mammary artery is the graft of choice in coronary artery bypass (CABG) surgery given its favorable longterm 90% patency at 10 years compared to saphenous vein grafts (SVG) [1, 2]. Preferential blood flow through these unligated thoracic branches and subsequent coronary steal phenomena have been reported as potential causes of angina [4]. Successful ligation of these side branches surgically or through catheter embolization has been documented in the literature to effectively relieve anginal symptoms through mainly subjective measures [5, 6]. We report here a case of refractory angina in a patient with history of CABG surgery where we physiologically demonstrate coronary steal via a large unligated thoracic side branch by measuring coronary flow reserve before and after selective thoracic side branch balloon occlusion and successful treatment by coil embolization of the branch

Case Report

Findings

Discussion