Left Internal Mammary Artery Bypass Research Articles

Reverse Controlled Antegrade and Retrograde Tracking in Left Internal Mammary Artery Bypass Grafts

Reverse Controlled Antegrade and Retrograde Tracking in Left Internal Mammary Artery Bypass Grafts

The Value of Left Internal Mammary Artery Flow Velocity in Predicting the Prognosis of Patients After Coronary Artery Bypass Grafting.

The purpose of this study was to explore the value of the left internal mammary artery flow velocity (LIMAV) measured by ultrasound before coronary artery bypass grafting (CABG) in predicting the prognosis of patients after left internal mammary artery (LIMA) bypass grafting. One hundred and four patients who underwent CABG with LIMA as the bridge vessel in the cardiovascular surgery department of our hospital between May 2018 and June 2019 were selected. All patients underwent transthoracic Doppler ultrasonography to measure LIMAV preoperatively. Intraoperatively, mean graft flow (MGF) and pulsatility index (PI) of the LIMA bridge were measured using transit time flow measurement (TTFM). The primary endpoint event in this study was cardiac death within 18 months after surgery. The Cox survival analysis showed that the MGF, the LIMAV and left ventricular ejection fraction (LVEF) were risk factors for death after CABG. The cut-offs of MGF, LIMAV and LVEF for the prediction of death after CABG were ≤ 14 mL/min (area under the curve (AUC): 0.830; sensitivity: 100%; specificity: 65.6%), ≤ 60 cm/s (AUC: 0.759; sensitivity: 65.5%; specificity: 85.3%), and ≤ 44% (AUC: 0.724; sensitivity: 50%; specificity: 88.5%), respectively. Compared with the use of MGF, MGF + LIMAV, combination of the MGF + LIMAV + LVEF (AUC: 0.929; sensitivity: 100%; specificity: 81.1%) resulted in a stronger predictive value (MGF vs. MGF + LIMAV + LVEF: P = 0.02). LIMAV measured by preoperative transthoracic ultrasound combined with intraoperative MGF and LVEF may have a greater value in predicting patients' risk of cardiac death after CABG.

Management of the left subclavian artery during aortic arch replacement using a frozen elephant trunk approach: a review.

The frozen elephant trunk (FET) technique for total aortic arch replacement extends repair into the proximal portion of the descending thoracic aorta. Several techniques and modifications of total arch replacement have been described in the literature, and many of these iterations are related to facilitating the distal anastomosis while preserving flow to the left subclavian artery (LSCA), as well as maintaining posterior circulation of the brain via the vertebral artery, by reducing the circulatory arrest time during reconstruction. Because of the LSCA's posterior and deep anatomic location in the chest, particularly in obese patients, this revascularization is often challenging; additional concerns regarding LSCA revascularization include patients with large aortic arch aneurysms, those with dissected or calcified arteries, and reoperation. A careful plan for reconstruction is necessary. Whether revascularization is performed preoperative, intraoperative, or postoperatively, every effort should be made to include the left subclavian artery as part of the operational approach. Revascularization techniques include reimplantation as part of the island patch or direct anastomosis, stenting, bypass, transposition or a hybrid approach. The importance of maintaining circulation of the LSCA cannot be overstated. Preserving flow to the spinal cord via collaterals minimizes the risk of cord injury during FET procedure. In patients with a patent left internal mammary artery bypass, left arm arteriovenous fistula for hemodialysis, dominant circulation, or direct aortic origin of the left vertebral artery, revascularization is necessary as well. In the case of initial sacrifice, arm claudication or steal syndrome usually dictates delayed extra-anatomic revascularization in the postoperative period.

A chart review on surgical myocardial debridging in symptomatic patients: a safe procedure with good long-term clinical outcome and coronary computed tomographic angiography results

Myocardial bridging is mostly diagnosed as an incidental imaging finding but can result in severe vessel compression and significant clinical adverse complications. Since there is still an ongoing debate when to propose surgical unroofing, we studied a group of patients where this was performed as an isolated procedure. In 16 patients (38.9 ± 15.7 years, 75% men) who had surgical unroofing for symptomatic isolated myocardial bridges of the left anterior descending artery, we retrospectively analysed symptomatology, medication, imaging modalities used, operative techniques, complications and long-term outcome. Computed tomographic fractional flow reserve was calculated to understand its potential value for decision-making. Most procedures were performed on-pump (75%, mean cardiopulmonary bypass 56.5 ± 27.9 min, mean aortic cross-clamping 36.4 ± 19.7 min). Three patients needed a left internal mammary artery bypass since the artery dived inside the ventricle. There were no major complications or deaths. The mean follow-up was 5.5 years. Although there was a dramatic improvement in symptoms, still 31% experienced atypical chest pain at various moments during follow-up. Postoperative radiological control was performed in 88%, showing no residual compression or recurrent myocardial bridge and patent bypass if performed. All postoperative computed tomographic flow calculations (7) showed a normalization of coronary flow. Surgical unroofing for symptomatic isolated myocardial bridging is a safe procedure. Patient selection remains difficult but introducing standard coronary computed tomographic angiography with flow calculations could be helpful in preoperative decision-making and during follow-up.

Bridging Collaterals of Chronically Occluded Left Internal Mammary Artery Bypass to Left Anterior Descending Artery

Bridging Collaterals of Chronically Occluded Left Internal Mammary Artery Bypass to Left Anterior Descending Artery

VENTRICULAR ELECTRICAL STORM SECONDARY TO KINKING OF LEFT INTERNAL MAMMARY ARTERY BYPASS GRAFT

VENTRICULAR ELECTRICAL STORM SECONDARY TO KINKING OF LEFT INTERNAL MAMMARY ARTERY BYPASS GRAFT

String sign recovery of the left internal mammary artery bypass graft.

String sign recovery of the left internal mammary artery bypass graft.

The Role of Color Doppler Ultrasonography in the Perioperative Period of Coronary Artery Bypass Grafting: Comparison with Transit-Time Flow Measurement

Introduction: The value of color Doppler ultrasonography (CDUS) with the supraclavicular approach for preoperative evaluation of the native left internal mammary artery (LIMA) as well as for the postoperative detection of LIMA graft patency was recently suggested. However, the parameters such as the flow volume and pulsatile index (PI) have not been studied in detail. Objectives: The objectives of this study were to analyze the LIMA data in the perioperative period and explore the relationships between the intraoperative graft flow with transit-time flow measurement (TTFM) and the postoperatively measured parameters with CDUS. Methods: Fifty-eight patients with significant stenosis (≥70%) or occlusions in left anterior descending artery (LAD) who were referred for isolated coronary artery bypass grafting (CABG) were enrolled in this study and examined by CDUS prior to CABG from April to July 2016. The perioperative measurements of proximal LIMA by CDUS were compared. In addition, the correlation between the intraoperative graft flow, such as the mean graft flow (MGF) and PI, and the immediate postoperative measurements of CDUS in LIMA bypassed grafts was statistically analyzed. Results: Six patients were excluded due to screening failure, or insufficient visualization of CDUS images for analysis. Fifty-two patients with in situ LIMA-LAD graft, with or without additional arterial grafts or saphenous vein grafts, were included in the final analysis. The postoperative diameters of proximal LIMA were not significantly different from preoperative diameters (2.21 ± 0.18 vs. 2.27 ± 0.22 mm, p = 0.070). The flow volume on the early postoperative CDUS significantly increased (39.77 ± 21.59 vs. 25.96 ± 13.17 mL/min, p < 0.001) and the PI significantly decreased (1.43 ± 0.46 vs. 4.20 ± 1.49, p < 0.001) versus those of preoperative measurements. The MGF had a moderate correlation with the flow volume on the early postoperative CDUS (r = 0.414, p = 0.002), and the PI by TTFM had a weak correlation with that by CDUS (r = 0.353, p = 0.010) as well. Conclusions: The MGF and PI by TTFM in CABG were associated with in situ LIMA graft parameters measured by CDUS studies. CDUS is a useful functional noninvasive tool for the preoperative screening and postoperative follow-up of patients with in situ LIMA bypass.

MINI OPCAB Operation: Surgical Technique

Introduction: We describe how to perform left internal mammary artery (LIMA) bypass to the left anterior descending (LAD) artery, the so-called MINI Off-pump Coronary Artery Bypass (MINI OPCAB). Materials and Methods: We included patients with a demonstrated predominant ischemia related to the LAD territory. Of 70 patients who were operated upon at the Benetti Foundation, 10 received hybrid revascularization. Surgical Technique: The patient is prepared as for a standard coronary bypass operation through sternotomy. The sternum is opened to the 3rd or 4th intercostal space depending on the anatomy, and a retractor is put in place. The left mammary artery is generally dissected to about 8 cm and isolated without the veins. Importantly, the angle of the superior part, where the mammary artery is attached to the sternum, needs to be below 20% to avoid any potential kinking. The pericardium is cleaned to identify the area of the pulmonary artery. The pericardium is opened to the apex and towards the right to around 5 to 6 cm initially. In most cases, the area of the LAD can be seen and the potential area of the anastomosis is defined. The patient is heparinized and the LAD is occluded with 5-0 Proline. A mechanical stabilizer is put in place and the anastomosis is performed. When the bypass is finished, and before sutures are tied, the stitches of 5-0 polypropylene around the artery are released, along with the clamp of the mammary artery; the anastomosis is then tied. The mechanical stabilizer is removed, the stitches of the pericardium are released and the flow of the graft is measured, while ensuring that there is no kinking. If the flow and Pulsatility and Resistance (PR) are acceptable, the mammary is fixed with 2 stitches of 7-0 polypropylene on both sides around 1 cm from the anastomosis. The heparin is reverted with protamine and a drain is put in place, while taking care to avoid any chance of touching the mammary artery or the anastomosis. The sternum is closed with 1 or 2 wires. Results: Operative mortality in this series was 0%; one patient was converted to sternotomy off-pump (1.4%). None of the grafts were revised after measurement with a Medistim system (Medistim ASA, Oslo, Norway). Fifty five patients (79%) were extubated in the operating room The average hospitalization stay was 60 hours (SD 17, 95% CI). Sixteen patients who underwent the LIMA-to-LAD procedure were restudied, with 100% patency. At 144 months, 82% of the patients were alive and 68% were asymptomatic. Conclusion: Additional clinical experience is required to be able to reproduce this operation on a large scale and expand the MINI OPCAB operation in hybrid revascularization.

Use of quantitative cardiovascular magnetic resonance myocardial perfusion mapping for characterization of ischemia in patients with left internal mammary coronary artery bypass grafts

BackgroundQuantitative myocardial perfusion mapping using cardiovascular magnetic resonance (CMR) is validated for myocardial blood flow (MBF) estimation in native vessel coronary artery disease (CAD). Following coronary artery bypass graft (CABG) surgery, perfusion defects are often detected in territories supplied by the left internal mammary artery (LIMA) graft, but their interpretation and subsequent clinical management is variable.MethodsWe assessed myocardial perfusion using quantitative CMR perfusion mapping in 38 patients with prior CABG surgery, all with angiographically-proven patent LIMA grafts to the left anterior descending coronary artery (LAD) and no prior infarction in the LAD territory. Factors potentially determining MBF in the LIMA–LAD myocardial territory, including the impact of delayed contrast arrival through the LIMA graft were evaluated.ResultsPerfusion defects were reported on blinded visual analysis in the LIMA–LAD territory in 27 (71%) cases, despite LIMA graft patency and no LAD infarction. Native LAD chronic total occlusion (CTO) was a strong independent predictor of stress MBF (B = − 0.41, p = 0.014) and myocardial perfusion reserve (MPR) (B = − 0.56, p = 0.005), and was associated with reduced stress MBF in the basal (1.47 vs 2.07 ml/g/min; p = 0.002) but not the apical myocardial segments (1.52 vs 1.87 ml/g/min; p = 0.057). Extending the maximum arterial time delay incorporated in the quantitative perfusion algorithm, resulted only in a small increase (3.4%) of estimated stress MBF.ConclusionsPerfusion defects are frequently detected in LIMA–LAD subtended territories post CABG despite LIMA patency. Although delayed contrast arrival through LIMA grafts causes a small underestimation of MBF, perfusion defects are likely to reflect true reductions in myocardial blood flow, largely due to proximal native LAD disease.

Incidental Finding and Endovascular Repair of a Left Internal Mammary Artery Aneurysm following a Multivessel Coronary Artery Bypass Graft

True aneurysms discovered within the internal mammary artery are extremely rare and typically have an asymptomatic occurrence. Their presentation and management have also been variable due to their low incidence, decreased detection, or lack of documentation. They have a high risk for morbidity or mortality as they can possibly rupture with increasing size and thus become life-threatening. Coronary CT angiography is the most definitive test for confirming and finding complications related to the aneurysm. With an increase in the aging population and advancement in the techniques used in coronary artery bypass grafting, it is likely that the rate of recorded occurrence of aneurysms and pseudoaneurysms will increase. Endovascular repair is currently the most favored treatment modality. In this report, we describe a case of a 74-year-old male who was incidentally found to have a left internal mammary artery aneurysm following complaints of chest pain related to another nearly occluded grafted vessel. To the best of our knowledge, and following an extensive literature review, this is likely the first documented case of a true aneurysm found within a left internal mammary artery bypass graft. The patient recovered well following placement of a covered stent; however, upon follow-up one year later, he was found to have stenosis of the same vessel, which was subsequently treated without further complication.

A Practical Approach to Hybrid Coronary Revascularization

Combined surgical and percutaneous coronary revascularization, ie, hybrid coronary revascularization (HCR) consists of surgical left internal mammary artery (LIMA) bypass to the left anterior descending artery (LAD) and percutaneous revascularization of other diseased coronary arteries. Developed as a 1-stage procedure, HCR has not been widely adopted by the cardiovascular community. The recommended minimally invasive approach through a small left thoracotomy incision is technically demanding, and same-day percutaneous revascularization requires a hybrid operating room that is not available in most hospitals. In this review, we consider present HCR protocols, barriers to widespread adoption of HCR, and we give special attention to the surgical approach for the LIMA graft to the LAD and the timing of percutaneous revascularization. We conclude that grafting the LIMA to the LAD through a median sternotomy approach and delaying the percutaneous revascularization may facilitate the widespread use of HCR in patients with multivessel coronary artery disease and a low to intermediate Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery score.

HEMODYNAMIC INVESTIGATION OF SUBCLAVIAN-CORONARY STEAL SYNDROME IN DIALYSIS PATIENTS WITH CORONARY ARTERY OCCLUSION AND DIFFERENT STENOSIS PERCENTAGES IN SUBCLAVIAN ARTERY

Purpose: Diseases of the coronary arteries represent critical cardiovascular bleakness and mortality around the world. The main focus of this study is to simulate hemodialysis patients undergoing Coronary Artery Bypass Graft (CABG) surgery by the left internal mammary artery. The survey is to investigate whether subclavian-coronary steal syndrome will occur in patients with stenosis in their left subclavian. Methods: A three-dimensional model of Brachial—Radial—Ulnar tree arterial system and dialysis graft are constructed and then simulated by the implementation of fluid–structure interaction (FSI) and non-FSI models. After consent was obtained, data attributed to dialysis patients who had undergone coronary bypass surgery at the Tehran Heart Center (THD) was collected. Results: Stenosis in the subclavian artery causes the left internal mammary artery (LIMA) graft to lack flow that, in CABG cases, is supplying the heart muscle. With the increase of stenosis from zero to 54%, the flow results show a negative flow indicating reversed flow in the artery. Meanwhile, the comparison between flow quantity of a normal Left Anterior Descending (LAD) and LIMA in case of 38% stenosis in subclavian shows that the amount of flow reaching the heart is less than standard. The threshold stenosis in the subclavian artery for which subclavian-coronary steal phenomena occurs is simulated to be around 54%. Furthermore, investigation of the effect of flow quantity in cases of hemodialysis versus nonhemodialysis shows that the flow is lessened in case of hemodialysis. Conclusions: In hemodialysis patients with more than 38% stenosis in left subclavian, it is well advised that LIMA bypass graft is not the preferred graft choice, and at 54% of subclavian stenosis, the steal phenomenon occurs.

OC62 REDO MITRAL SURGERY AND HOSPITAL OUTCOME: IMPACT OF FAILED MITRAL VALVE REPAIR

Background and Aim: Mitral valve repair is the gold standard for mitral valve regurgitation, even if failed mitral repairs (FMR) have been reported. The aim of this study was to evaluate the impact of FMR on early outcome after redo mitral surgery. Methods: Operative mortality and major morbidity events from 920 redo mitral procedures at nine European centres were analysed. Statistical analysis was performed by the SPSS 13.0 program for Windows (SPSS, Inc., Chicago, IL, USA). To identify indipendent predictors of operative deaths, variables with a P &lt; 0.10 at univariable analysis were included in the regression models. All the outcome parameters were then adjusted by propensity matching, to compare similar cohorts of patients with FMR or diseased native mitral valves and similar cohorts of patients with FMR and malfunctioning prostheses. Results: FMR did not impact mortality at multivariable analysis (P = 0.64). Propensity-matched cohorts of FMR and native mitral valves showed no differences in mortality (P = 0.69). A preoperative Global Initiative for Chronic Obstructive Lung Disease score &gt;2 chronic lung disease (COPD) (OR 15.2, P &lt; 0.01), left ventricular ejection fraction &lt;30% (odds ratio (OR) 21.5, P = 0.005), major injury to cardiovascular structures at re-entry (OR 27.2, P &lt; 0.01) or to patent left internal mammary artery-coronary artery bypass graft (OR 7.6, P = 0.03) predicted mortality in the FMR population. Conclusions: A failed mitral repair does not impact hospital outcome of redo surgery. Severe left ventricular dysfunction, COPD and injury at re-entry predict adverse early outcome.

High-Output Cardiac Failure and Coronary Steal With an Arteriovenous Fistula

Creation of an arteriovenous access for hemodialysis can provoke a sequence of events that significantly affects cardiovascular hemodynamics. We present a 78-year-old man with end-stage renal disease and concomitant coronary artery disease previously requiring coronary artery bypass grafting including a left internal mammary graft to the left anterior descending artery, ischemic cardiomyopathy with left ventricular systolic dysfunction, and severe aortic stenosis who developed hypotension unresponsiveto medical therapy after recent angioplasty of his ipsilateral arteriovenous fistula for high-grade outflow stenosis. This case highlights the long-term effects of dialysis access on the cardiovascular system, with special emphasis on complications such as high-output cardiac failure and coronary artery steal syndrome. Banding of the arteriovenous fistula provided symptomatic relief with a decrease in cardiac output. Avoidance of arteriovenous access creation on the ipsilateral upper extremity in patients with a left internal mammary artery bypass graft may prevent coronary artery steal syndrome.

Long-term Outcomes of Carotid-Subclavian Bypass in the Setting of Thoracic Endovascular Aortic Repair

Subclavian artery revascularization is frequently performed in the setting of thoracic endovascular aortic repair (TEVAR) for a variety of indications ranging from prophylactic prevention of upper extremity and spinal cord ischemia to preservation of hemodialysis access or left internal mammary artery coronary artery bypass graft. Despite this, there is little information on the short- and long-term outcomes of patients undergoing carotid to subclavian artery bypass. We sought to define the outcomes associated with this procedure. Patients undergoing carotid-subclavian bypass in conjunction with TEVAR between June 2005 and September 2016 were retrospectively identified from a prospectively maintained, single-center aortic surgery database. Categorical and continuous variables were compared using χ2 and Wilcoxon rank sum tests, respectively. The 30-day outcomes specific to the carotid-subclavian bypass procedure were analyzed, including nerve injury, bleeding complications, and local vascular complications. All preoperative and postoperative chest radiographs were carefully analyzed to assess for hemidiaphragm elevation indicative of phrenic nerve palsy. Long-term outcomes included primary graft patency and anastomotic complications. Of 579 patients undergoing TEVAR during this time interval, 114 patients (20%) underwent concomitant carotid-subclavian bypass. The cohort was 39% female (n = 44), with a mean age of 65 ± 14 years. The majority of conduits were 8-mm polytetrafluoroethylene grafts (n = 107 [92.2%]), with a minority being reversed saphenous vein grafts (n = 4 [3.5%]). The bypass procedure was done concomitantly at the time of TEVAR in 90.4% (n = 103) of cases. The short-term complication rate attributed specifically to the carotid-subclavian bypass was 21% (n = 24). These complications included neck hematoma requiring re-exploration in 0.9% (n = 1), recurrent laryngeal nerve palsy in 5.3% (n = 6), axillary nerve palsy in 1.8% (n = 2), and phrenic nerve palsy in 13.2% (n = 15) of patients. The 30-day all-cause mortality rate was 5.3% (n = 6), and the rate of permanent paraparesis or paraplegia was 0.9% (n = 1). Of the operative survivors (n = 108), follow-up imaging of the bypass graft was available in 84% (n = 96) of patients. Actuarial primary graft patency was 97% at 10 years (Fig). There were three patients (2.5%) with bypass graft occlusions, two of which were clinically silent and detected in follow-up imaging. The third was detected because of the symptoms of subclavian steal and required repeated revascularization. Two patients (1.8%) developed a late anastomotic pseudoaneurysm requiring either endovascular (n = 1) or surgical (n = 1) intervention. Carotid-subclavian bypass for revascularization of the subclavian artery performed in the setting of TEVAR is durable, although the true complication rate is likely to be higher than generally reported in the literature because of a not insignificant rate of phrenic nerve palsy. These data should serve well as “gold standard” comparison data for emerging branch graft devices.

Impact of failed mitral valve repair on hospital outcome of redo mitral valve procedures.

The prognostic impact of failed mitral valve repair (FMR) on in-hospital outcome after redo mitral valve surgery has not been thoroughly investigated. Hospital outcomes after redo mitral valve surgery because of an FMR in patients from nine European centres were reported. Logistic regressions identified predictors of mortality in combined or isolated redo mitral valve operations. Hospital outcome was compared between propensity-matched cohorts with FMR and native mitral valves in the context of redo surgery and FMR versus failed prostheses. A total of 246 patients with FMR yielded a 6.5% mortality rate at redo surgery. FMR per se did not impact mortality at multivariable analysis ( P = 0.64). A preoperative Global Initiative for Chronic Obstructive Lung Disease (GOLD) score ≥2 chronic obstructive lung disease (COPD) (OR 15.2, P < 0.01), left ventricular ejection fraction <30% (odds ratio (OR) 21.5, P = 0.005), major injury to cardiovascular structures at re-entry (OR 27.2, P < 0.01) or injury to patent left internal mammary artery-coronary artery bypass graft (OR 7.6, P = 0.03) predicted mortality in the whole FMR population. GOLD ≥ 2 COPD (OR 12.3, P = 0.049), age at surgery (OR 1.15 for each incremental year, P = 0.049) and cardiopulmonary bypass duration (OR 1.02, P = 0.022) predicted mortality in isolated redo mitral valve surgery for FMR. The fourth (> 68 years = 13.8% mortality) and the fifth quintiles of age (≥73.4 years = 14.8%) reported the highest mortality (OR 3.8 and 4.2 respectively, P = 0.002) in this subgroup. Propensity-matched cohorts of FMR and native mitral valves in the context of redo surgery showed no differences in terms of mortality ( P = 0.69) and major morbidity (acute myocardial infarction P = 0.31, stroke P = 0.65, acute kidney injury P = 1.0), whereas more perioperative dialysis ( P = 0.04) and transfusions ( P = 0.02) were noted in propensity-matched failed prostheses compared to FMR. A failed mitral repair does not impact hospital outcome of redo surgery. Given the role of severe left ventricular dysfunction and advanced age on hospital mortality rates, an early indication for redo surgery may improve outcome.

Extensive Dissection of the Left Internal Mammary Artery Graft and Emergency Bail Out

Background: Left internal mammary artery (LIMA) bypass graft to the left anterior descending artery (LAD) have better long-term survival when compared with the use of a venous conduit to the LAD. It is a very important lifeline for coronary artery bypass patients and dissection of the LIMA is often disastrous. This case illustrates an extensive dissection of the LIMA, involving the subclavian artery and aorta after bypass graft angiography. This was followed by an emergency bail out procedure. Case Report: A 60-year-old gentleman presented with unstable angina underwent a routine diagnostic angiogram. Shortly after automated contrast injection of the left internal mammary artery (LIMA) graft, a column of contrast was found trapped in the subclavian artery. A review of the LIMA angiography revealed a spiral dissection extending distally from the ostial to distal LIMA, and also proximally from LIMA to subclavian artery down the aortic arch. Patient immediately deteriorated with hypotension and experienced chest pain. Emergency stenting of the left subclavian artery was performed. However, LIMA remained occluded. Cardiothoracic surgeons were consulted but acute redo coronary artery bypass was considered to be extremely high risk. In an attempt to bail-out the acutely occluded LIMA, we proceed with percutaneous coronary intervention of the native left anterior descending (LAD) artery chronic total occlusion. Fortunately, this was successful and stents were implanted from left main artery to distal LAD..

Coronary Steal by LIMA Bypass Graft Side-Branches: Physiologic Functional Evaluation and Coil Embolisation

Thoracic side branches of the left internal mammary artery (LIMA) has been reported to cause a coronary steal phenomena if not ligated at the time of surgery. The haemodynamic significance of the unligated side branches remains controversial. We present a case of coronary steal phenomena with an objective evidence of ischaemia that resolved after coil embolisation. A 61-year-old male underwent CABG in 1999 for unstable angina. The LAD received a LIMA graft, vein grafts to the diagonal, obtuse marginal and right coronary artery. His presenting symptom prior to CABG was shortness of breath. He remained symptom free until a year ago where he presented with progressive shortness of breath on minimal exertion despite medical therapy. He underwent a diagnostic coronary angiogram, which revealed severe narrowing in the left main stem, ostial circumflex and proximal LAD as well as occluded right coronary artery. All his grafts were patent. The LIMA was also patent but two unligated thoracic branches were noted. The possibility of coronary steal phenomena was entertained and the patient was brought back to the catheterisation laboratory for fractional flow reserve (FFR) study with a view of coiling the unligated side branches if the FFR was positive. After maximal hyperaemia using intravenous adenosine infusion at 140 mcg/kg/min, maximal FFR was calculated at 0.74 in the distal LAD. Both LIMA branches were occluded with balloons and FFR increased to 0.94. Therefore both branches were coiled and repeat FFR was 0.94 after coil embolisation. Six months later, the patient is off his anti-anginal therapy and is symptom free.

Coronary-subclavian Steal Syndrome in a Patient with Takayasu Arteritis

A 37-year-old woman who had undergone coronary artery bypass grafting (CABG) surgery for left main and right coronary ostial lesions 2 years prior presented with angina and transient visual dimness. Computed tomography angiography showed a patent left internal mammary artery (LIMA) bypass graft and concentric narrowing with perivascular thickening around the arch vessels. The patient was diagnosed with Takayasu arteritis with coronary subclavian steal syndrome (CSSS). Thoracic angiography revealed severe stenosis of the left proximal subclavian artery (SCA) and reverse flow from the coronary artery to the distal left SCA via the LIMA graft. Successful percutaneous stenting of the left SCA was performed together with stenting of the right common carotid artery (CCA). The patient’s symptoms were completely resolved. This case is informative since it shows that Takayasu arteritis can manifest as angina due to coronary ostial lesions and then can involve arch vessels, which can lead to CSSS in patients with CABG. (Korean J Med 2016;91:37-41)