Recurrent angina pectoris in patients with internal mammary artery to coronary artery bypass: treatment with coil embolization of unligated side branches

A case of LIMA side branch coronary steal syndrome: a role for embolization

Failure to close the side branches of the internal mammary artery can result in ischemia due to coronary steal through a patent mammary artery side branch after coronary artery bypass grafting. The authors present the case of a 56-year-old man with recurrent angina after 6 month surgical myocardial revascularization underwent coronary angiography that showed patent left branch of the internal mammary artery. After demonstration of inducible ischemia, effective percutaneous treatment was performed using coil embolization, improving blood flow and clinical symptoms.

Coils embolization use for coronary procedures: Basics, indications, and techniques

The use of coils is fundamental in interventional cardiology and can be lifesaving in selected settings. Coils are classified by their materials into bare metal, fiber coated, and hydrogel coated, or by the deliverability method into, pushable or detachable coils. Coils are delivered through microcatheters and the choice of coil size is important to ensure compatibility with the inner diameter of the delivery catheter, firstly to be able to deliver and secondly to prevent the coil from being stuck and damaged. Clinically, coils are used in either acute or in elective setting. The most important acute indication is typically the sealing coronary perforation. In the elective settings, coils can be used for the treatment of certain congenital cardiac abnormalities, aneurysms, fistulas or in the treatment of arterial side branch steal syndrome after CABG. Coils must always be delivered under fluoroscopy guidance. There are some associated complications with coils that can be acute or chronic, that nictitates regular followed-up. There is a need for education, training and regular workshops with hands-on to build the experience to use coils in situations that are infrequently encountered.

Utilization and outcomes of transcatheter coil embolization for various coronary artery lesions: Single-center 12-year experience

OBJECTIVE

Determining the outcomes of transcatheter coil embolization (TCE) for several coronary artery lesions.

BACKGROUND

TCE has been used as a treatment modality for various lesions in the coronary circulation. However, data on the efficacy and safety of TCE to treat coronary artery fistula (CAF), left internal mammary artery (LIMA) side-branch, coronary artery perforation (CAP), coronary artery aneurysm (CAA), and coronary artery pseudoaneurysm (CAPA) are limited.

METHODS

We conducted a retrospective, descriptive analysis of all TCE devices in coronary lesions at our center from 2007 to 2019. Forty-one studied lesions included 25 CAF, 7 LIMA side-branch, 5 CAP, 2 CAA, and 2 CAPA. Short- and 1-year mortality and hospital readmission were reported, in addition to coil-related complications and procedural success.

RESULTS

The utilization rate of TCE in coronary artery lesions at our center was found to be 33.8 per 100,000 percutaneous coronary intervention procedures over 12 years. Successful angiographic closure was achieved in 37 out of 41 (87.8%) cases (88, 100, 60, 100, and 100% of CAF, LIMA side-branch, CAP, CAA, and CAPA, respectively). No adverse events were directly related to TCE among the LIMA, CAA, and CAPA cases, and only one patient with CAF required reintervention at 3 months due to coil migration.

CONCLUSIONS

Coil embolization in our institution was safe and effective in treating different coronary circulation abnormalities with a 87.8% overall success rate. Further study on the use of vascular plug devices in cases such as CAF or LIMA side-branch would be beneficial to understand the treatment options better.

Assessment of lateral costal artery with CT angiography: determination of prevalence and vessel length in the general population and its potential impact for coronary artery bypass grafting

OBJECTIVES

Standard treatment for severe coronary artery disease (CAD) is coronary artery bypass grafting (CABG). An underreported branch of the internal mammary artery, the lateral costal artery (LCA), can cause a steal phenomenon after CABG, resulting in angina. The aim of this study was to determine the prevalence and length of LCA based on CT angiography (CTA).

METHODS

This retrospective study included adult patients undergoing a thoracic CTA between January 2016 and August 2018. Exclusion criteria were prior CABG, insufficient clinical information, or inadequate image quality. Two blinded, independent readers reviewed all studies for the prevalence of the LCA. Positive cases were reviewed by two readers (R1/R2) for side distribution and vessel length, measured in intercostal spaces (ICS). Study indication, aortic size, and coronary calcification were noted.

RESULTS

LCA was present in up to 42/389 (11%) of studies (60.3 ± 16.7 years, 30 males). The LCA was most commonly unilateral (n = 23, 55%). Median vessel length was 2 ICS (IQR 0; 3). Logistic regression was not significant in vessel distribution for sex (OR 0.6, 95% CI 0.28-1.15; p = 0.11). Inter-observer agreement in detecting LCA was substantial (kappa 0.71, 95% CI 0.59-0.83) and excellent for side/length distribution (kappa 0.94, 95% CI 0.82-1.0; ICC 0.96, 95% CI 0.93-0.98).

CONCLUSION

The LCA is uncommon and most often unilateral and extends the third rib. Radiologists should be aware of this vessel and its potential role in angina after CABG, particularly when large.

KEY POINTS

• LCA is an uncommon normal variant that is reported to cause angina pectoris after CABG. • CT angiography can reliably detect the LCA. It is most often unilateral and spans two intercostal spaces.

Side-Branch of Internal Mammary Artery Bypass Graft Causing Coronary Steal

A case of coronary steal syndrome caused by a large unligated branch of the left internal mammary artery in a patient who had undergone myocardial revascularization is described. The presence of recurrent angina, a positive exercise stress test, and repeat angiography showing a lateral branch of the mammary artery led to a diagnosis of the coronary steal phenomenon. Surgical ligation of the branch was performed and the patient became symptom-free with a negative exercise stress test.

Recurrence of coronary-subclavian steal syndrome after successful angioplasty of malfunctioning arteriovenous fistula

We report a case of coronary-subclavian steal syndrome, which had been masked by a malfunctioning hemodialysis access vessel and then reappeared after a successful angioplasty of multiple stenoses in the arteriovenous fistula of the left arm in a 61-year-old man. This case suggests that coronary-subclavian steal syndrome should be considered before a coronary artery bypass grafting surgery using internal mammary artery conduit is done, especially when hemodialysis using the left arm vessels is expected.

Endovascular treatment of coronary steal

Postoperative angina is generally caused by subclavian artery stenosis or flow diversion in anomalous or large unligated side branches of the left internal mammary artery. Previously, surgery was the treatment method for unligated side branches, but with the improvements of interventional techniques, it is shown that endovascular treatment is also effective in these patients. Herein, we present successful endovascular treatment of a large unligated intercostal side branch causing recurrent angina.

Transcatheter occlusion of a large intercostal side-branch of left internal mammary artery bypass with detachable platinum coils

Intercostal branches of the internal mammary artery (IMA) are usually tied off during IMA-bypass surgery. Some side-branches may be missed, however, due to anatomical variants or during minimal invasive procedures with limitation of the surgeon's ability to ligate proximal branches. There are a number of reports in the literature describing interventional closure of side-branches using Gianturco coils. Following embolization or malposition, however, these coils may be extremely difficult to retrieve from coronary arteries. We report about interventional embolization of a IMA side-branch with detachable micro-coils in a patient with symptomatic coronary steal. Detachable coils are safer than Gianturco coils and are an effective method to abolish symptomatic coronary steal due to unligated intercostal branches of the IMA graft.

Lateral costal artery: Accessory thoracic vessel of clinical interest

The lateral costal artery (LCA), a supernumerary branch of the internal thoracic artery (ITA), occurs in several ethnic groups on one side of the thorax or on both, in 15-30% of cases. It has been considered responsible for the "steal-syndrome" of the coronary blood after coronary artery bypass grafting and it used occasionally for myocardial revascularization. To clarify its functional significance, an interpretation based on our findings and human and comparative anatomy and embryology has been attempted. We report on a case where a right LCA of about 2 mm in caliber, rising from the ITA 2.5 cm below the subclavian, coursed as far as the 4th intercostal space for a distance of 13 cm after the anterior axillary line. Anastomosing with the intercostal arteries, it can act as a blood derivative circuit of the thoracic wall. Embryologically, this artery, like the normal parietal arteries of the trunk, might form a longitudinal channel connecting the intersegmental arteries. In mammals having a thoracic cage transversely restricted (quadrupeds), the ITA is more lateral than in primates having a circular thorax, and gives off a ventral branch toward the sternum. It might be hypothesized that the sternal branch occurring in quadrupeds, undergoing adaptation to the thoracic shape of primates, may become the main trunk of the ITA, whereas the LCA may be the remnant of the ITA of quadrupeds. Because the LCA ran partly along the "milk line" of humans, it might be regarded as a supernumerary mammary artery.

Fallacy of thoracic side-branch steal from the internal mammary artery: Analysis of left internal mammary artery coronary flow during thoracic side-branch occlusion with pharmacologic and exercise-induced hyperemia

In some patients, myocardial ischemia after coronary artery bypass graft surgery has been attributed to a coronary steal phenomenon through a thoracic side branch originating from the left internal mammary artery (LIMA), even in the absence of subclavian or LIMA stenosis. To demonstrate that coronary flow through the LIMA is unchanged by occlusion of a LIMA side branch, we examined LIMA coronary flow velocity measurements (0.014" Doppler flow wire) in three patients at rest, during adenosine hyperemia, and again during hyperemia induced by left arm exercise before and again after the balloon occlusion of the thoracic side branch. For the three patients, no significant changes in resting or hyperemic flow were noted due to side-branch occlusion. Before side-branch occlusion, pharmacologic intra-arterial (adenosine) coronary flow reserve (hyperemic-to-basal flow velocity ratio) was 2.6, 1.5, and 3.2 and exercise flow reserve was 2.1, 1.3, and 1.2, respectively. After side-branch occlusion, pharmacologic coronary flow reserve was 2.5, 1.8, and 2.7 with exercise flow reserve of 1.8, 1.1, and 1.3, respectively. Under most ordinary circumstances, thoracic side-branch steal does not exist and that side-branch occlusion does not alter LIMA flow at rest or during pharmacologic or exercise-induced hyperemia. These data further suggest that a demonstration of the physiologic value of side-branch occlusion should precede surgical or percutaneous interruption of the thoracic artery in such patients.

Incidence and size of lateral costal artery in 103 patients

BACKGROUND

The internal mammary artery is used widely as a conduit for coronary artery bypass grafting. Most practicing cardiac surgeons are unaware of an aberrant side branch, the lateral costal artery (LCA), that arises proximally. Unligated, this side branch has been held responsible for early recurrence of angina in a small number of patients in the literature. In this study we identified the incidence and length of the LCA.

METHODS

We studied 103 patients who had coronary artery bypass grafting with bilateral internal mammary arteries. The presence or absence of an LCA was noted, and a record was made of the number of intercostal spaces traversed.

RESULTS

Thirty-one of 103 patients had an LCA on one or the other side. Twenty-five patients had bilateral LCAs in which length was equal on both sides in 18. Median length was two intercostal spaces (range, one to six). The LCA extended to the fifth space or beyond in 5 patients.

CONCLUSIONS

The LCA was present in one third of patients who had coronary artery bypass grafting. A few patients had vessels sizable enough to raise concerns about recurrence of angina. It is prudent to exclude the presence of an LCA in all patients who have cardiac operations.

Coronary steal by IMA bypass graft side-branches: a novel therapeutic use of a new detachable embolization coil

Coronary artery steal syndromes following coronary artery bypass grafting (CAB) may occur as a result of the presence of large side-branches arising from the internal mammary artery (IMA). We report the first successful deployment of a new detachable vascular embolization coil device to occlude the IMA side-branches in two patients. Optimal positioning is easily obtained with the unique operator-controlled, safety-release protected mechanism of this device. Complete retraction is possible, with safe and efficient removal of the coil even after deployment. This feature was appreciated during one procedure in which the initially selected coil was found to be oversized, requiring immediate removal. Acute thrombo-occlusion of the IMA side-branches in both patients was observed. We conclude that IMA bypass graft side-branches causing coronary steal can be safely and effectively occluded using this new technique. However, due to observed delayed partial recanalization noted on distant follow-up angiography, we recommend placement of multiple coils at the time of initial embolization.