Natural Right Internal Mammary Artery to Left Circumflex Artery Bypass

Abstract

A 76-year-old man who had a history of diabetes mellitus, hypertension, and hyperlipidemia was referred to our hospital for surgical intervention of his coronary artery. He does not have any history of chest trauma previously. This patient also had a history of 2 previous percutaneous coronary artery interventions. In 2000, he underwent stent insertion to the right coronary artery (RCA) and the left circumflex artery (LCX) because of posterior acute myocardial infarction. In 2007, stent insertion was performed for a newly developed lesion of the RCA. Since that procedure, the patient was stable without chest pain. However, in 2013, he complained of severe chest pain on exertion and was emergently admitted to a local hospital. An ECG showed anterior wall ischemia. Acute coronary syndrome was suspected. Emergency coronary angiography was performed and revealed tight left main stenosis, 75% stenosis of the proximal left anterior descending artery, 99% stenosis of the proximal LCX, and 90% stenosis of the RCA. There was flow competition between the native LCX and the collateral artery (Figure 1, Movie I in the online-only Data Supplement). An internal mammary artery angiography was performed and showed that 1 of the pericardial branches of the right internal mammary artery (RIMA) arose from the proximal part of the RIMA, communicated with the proximal LCX, and perfused the entire LCX area (Figure 2, Movie II in the online-only Data Supplement). There was no communication between the left internal mammary artery (LIMA) and the coronary arteries.This patient underwent coronary artery bypass grafting as follows: the LIMA to the left anterior descending artery, the RIMA to the first diagonal branch, and the saphenous vein graft to the posterior descending artery and the posterior lateral artery). When the RIMA was harvested, a large pericardial branch of the RIMA was identified right to the thymic tissue. The branch coursed caudally and posteriorly toward the pericardium. This branch was preserved, and the RIMA was used for in situ grafting to the first diagonal branch as usual. The postoperative course was uneventful, and the patient was extubated the next morning. A postoperative coronary angiography indicated that all grafts were patent. An angiography of the saphenous vein graft to the diagonal branch showed that the graft was patent and showed retrograde filling of the pericardial branch of the RIMA (Figure 3, Movie III in the online-only Data Supplement).Extracardiac coronary collateral perfusion from the internal mammary artery has been described previously by postmortem studies.1 By injecting a colloidal suspension of carbon particles to the coronary arteries at autopsy, 1 those studies found that the largest arteries was the pericardiacophrenic branches of internal mammary arteries. Other arteries, such as the anterior mediastinal, pericardial, bronchial, superior, and inferior phrenic, and intercostal and esophageal branches of the aorta were described as extracardiac arteries anastomosed with coronary arterie...

Effect of Permanent Right Internal Mammary Artery Closure on Coronary Collateral Function and Myocardial Ischemia

“…6–8 Seven case reports have documented the existence of naturally occurring angiographic anastomoses between one of the IMAs and the human coronary circulation. 9–15 Blair et al measured increased coronary artery blood flow after experimental IMA ligation. More recently, a study in 8 dogs undergoing coronary artery constriction and IMA ligation has failed to reveal myocardial microsphere perfusion via IMA in the single animal, which survived the study protocol.…”

Natural internal thoracic-to-coronary artery collateral network

“…2,3 Another two reports described right or left ITA to the left circumflex artery in patients with an occluded left circumflex artery. 4,5 To our best knowledge, a collateral pathway from the left ITA to the LAD in a patient with an occluded LAD has not yet been reported. ITA angiography may sometimes be very useful in treating ischemic heart disease.…”

“…Only four clinical articles describing spontaneous communication between the ITA and a coronary artery in a patient with an occluded coronary artery have been reported thus far. [2][3][4][5] Two reports described right ITA-to-right coronary artery communication in patients with an occluded right coronary artery. 2,3 Another two reports described right or left ITA to the left circumflex artery in patients with an occluded left circumflex artery.…”

“…2,3 Another two reports described right or left ITA to the left circumflex artery in patients with an occluded left circumflex artery. 4,5…”

Stimulating Extracardiac Collaterals via Right Internal Mammary Artery Occlusion

“…Over subsequent decades, sporadic rare cases suggested that IMA pericardiophrenic branches could be called forth. [4][5][6] After years of fruitless research by early investigators, Stoller et al 1 resurrected the extracardiac collateral concept in a remarkable experiment in 2014. By using temporary balloon occlusion of the ipsilateral IMA and inducing temporary ischemia in the native coronary also by balloon occlusion while quantitating the CFI, they found that RIMA occlusion increased RCA CFI while LIMA occlusion increased left anterior descending artery CFI.…”