Left Internal Mammary Artery Graft Research Articles

ACUTE CORONARY SYNDROME IN A PATIENT WITH LEFT SUBCLAVIAN OCCLUSION AND ANTEROLATERAL CORONARY STEAL

Abstract This is a 57–year–old male patient suffering from multiple cardiovascular risk factors: obesity, arterial hypertension, dyslipidemia, type 2 diabetes mellitus, active smoker. Chronic obstructive pulmonary disease. Stage 2 chronic kidney disease. Peripheral vascular disease with previous bilateral thromboendarterectomy and percutaneous revascularization of the lower limbs. Stable angina for which three years ago he underwent Coronary Artery Bypass Graft: left internal mammary artery (LIMA) to left anterior descending artery combined with saphenous vein grafts to the main obtuse marginal branch. The patient presented with Acute Coronary Syndrome non ST–segment elevation myocardial infarction (N–STEMI), intermittent episodes of chest pain due to mild exertion in the previous days. Antero–lateral ST depression and inverted T waves, associated with a mild reduction in left ventricular systolic function due to hypokinesia of the antero–lateral walls and increased troponin values were present. Coronary angiography documented patency of the LIMA graft without evidence of any culprit lesions on the coronary branches. However, selective angiography documented a sub–occlusion of the proximal left subclavian artery (Figure 1). A computed tomography scan confirmed a hyperdense calcified plaque occluding 95% of the origin of the left subclavian artery. The patient then underwent angioplasty with stenting of the left subclavian artery (Figure 2). Subclavian coronary steal syndrome usually presents with exertional angina, but rarely can cause Acute Coronary Syndrome. During coronary angiography performed for Acute Coronary Syndrome and in the absence of detection of clear coronary culprit lesions, selective angiography of the subclavian artery may confirm the suspicion of coronary steal syndrome.

Should the left internal mammary artery (LIMA) be imaged before radiotherapy in cases of unexpected early acute coronary syndrome?

Abstract Funding Acknowledgements None. Case A 41-year-old male patient presented to the cardiology outpatient clinic with a complaint of exertional chest pain persisting for the past 4 months, along with occasional palpitation attacks. In his medical history, aside from being diagnosed with lymphoma 15 years ago, there were no known additional comorbidities. The electrocardiogram (EKG) revealed sinus rhythm (84 beats/minute), and the blood tests showed creatinine: 0.81 mg/dL, WBC: 11.26 mm^3, LYM: 3.69 mm^3. Transthoracic echocardiography demonstrated an ejection fraction (EF) of 60%, with no additional pathologies except for grade 1 diastolic dysfunction. Considering the presence of typical chest pain, coronary imaging was performed to assess for stable angina. The coronary imaging revealed a lesion extending from the left main coronary artery (LMCA) to the proximal left circumflex artery (CX), with an 80% stenosis in the mid-segment of the LMCA, a 60% stenosis at the narrowest point of the CX proximal segment, and an 80% stenosis in the proximal right coronary artery (RCA). The left circumflex artery obtuse marginal branches (CX OM) appeared thin and extensively diseased (Figure-1) The patient was promptly scheduled for early coronary artery bypass grafting (CABG), transferred to the cardiac surgery intensive care unit, and underwent a successful coronary bypass procedure with LAD-LIMA, Ao-saphenous-IM-saphenous-CxOM1 (sequential) grafting. Throughout the postoperative follow-up period, the patient continued to experience exertional chest pain despite medical treatment. A repeat coronary angiography was performed, revealing that the bypass grafts were opened, but a diffuse 80% stenosis was detected at the mid-segment of the LIMA graft, prior to the anastomosis.(Figure-2) Successful stent placement was performed at the narrowest point of the LIMA mid-segment (Figure-3).The patient had no anginal complaints during post-procedure follow-up and has been stable under observation. Discussion Routine clinical practice does not involve LIMA imaging in patients who have undergone diagnostic coronary angiography with multi-vessel involvement and a CABG decision. However, the use of coronary artery bypass graft surgery (CABG) may entail a risk of rendering the graft unusable due to extensive mediastinal fibrosis and radiation-induced damage to the left or right mammary artery. Therefore, in patients with a history of radiation exposure in the thoracic region and a CABG decision, the visualization of the intermammary artery during coronary angiography and the consideration of alternative grafts, such as the radiation-free radial artery, or the necessity for high-risk percutaneous stent implantation, should be discussed.figure-1figure-2

Pre-Coronary Artery Bypass Grafting Computed Tomography-Based Fractional Flow Reserve Predicts Graft Failure: Implications for Planning Invasive Treatment of Coronary Artery Disease.

The aim of the study is to evaluate whether a pre-coronary artery bypass grafting (CABG) coronary computed tomography-based fractional flow reserve (FFR-CT) result at the site of a future anastomosis would predict the graft failure in patients undergoing CABG. In 43 patients who had coronary computed tomography angiography (CCTA) prior to the CABG, follow-up CCTA were acquired >12 months post-CABG procedure. The FFR-CT values were simulated on the basis of the pre-CABG CCTA. Based on follow-up CCTA, the anastomosis sites and the graft patency were determined. The graft failure was defined as either its stenosis >50% or occlusion. Ninety eight (44 saphenous, 54 left or right internal mammary artery) grafts were assessed. Eighteen grafts from 16 patients were dysfunctional on follow-up CCTA. The FFR-CT values at the location of future anastomosis were higher in dysfunctional than in normal grafts (0.77 [0.71-0.81] vs 0.60 [0.56-0.66], respectively, P = 0.0007). Pre-CABG FFR-CT (hazard ratio = 1.1; 95% CI: 1.012-1.1, P = 0.0230), and bypass graft to right coronary artery (hazard ratio = 3.7; 95% CI: 1.4-9.3 vs left anterior descending artery) were independent predictors of graft dysfunction during follow-up. The optimal threshold of FFR-CT to predict graft failure was >0.68 (sensitivity 88.9% (95% CI: 65.3-98.6), specificity 63.7% (95% CI: 52.2-74.2), positive predictive value 35.6% (95% CI: 28.3%-43.5%), negative predictive value 96.2% (95% CI: 87.2%-99.0%)). Pre-CABG functional FFR-CT predicts future coronary bypass graft failure. This shows utility of FFR-CT for guiding coronary revascularization and also suggests significance of physiological assessment prior to CABG.

Optimizing Internal Mammary Artery Harvest and Preparation

The left internal mammary artery (LIMA) graft plays a pivotal role in coronary artery bypass surgery, offering unparalleled efficacy in revascularization. This review paper delves into the multifaceted considerations surrounding LIMA utilization, aiming to provide a comprehensive understanding of optimal approaches. The study encompasses the alleviation of spasm, selection of graft harvesting techniques, identification of ideal vasodilators, and exploration of optimal delivery methods. Through an analysis of extensive research spanning the past three decades, this review elucidates critical insights for cardiac surgeons and researchers alike. The review emphasizes the ubiquity of severe spasms in harvested LIMA and examines interventions to mitigate this challenge. Studies highlighting the efficacy of papaverine administration through various routes underscore the need for tailored approaches based on clinical context. The debate between skeletonized and pedicled LIMA harvests is explored, revealing the advantages and complexities associated with each technique. Findings suggest that while skeletonized grafts offer enhanced flow, the decision remains multifaceted due to potential complications. Addressing the quest for the ideal vasodilator, the review juxtaposes papaverine and sodium nitroprusside, presenting both as viable options. Despite ongoing discussions, the cost-effectiveness and accessibility of papaverine have positioned it as the favored choice among clinicians. Optimal delivery methods emerge as a crucial factor in graft success, with perivascular injection showing promise in promoting sustained and improved flow rates. The clinical implications of these findings are substantial. By integrating the evidence presented, cardiac surgeons can make informed decisions, maximizing graft patency and patient outcomes. Further, research avenues are identified, encompassing refined delivery techniques, comprehensive comparisons of vasodilators, and long-term clinical outcome evaluations. In conclusion, this review underscores the intricate considerations essential for successful LIMA utilization. By addressing spasms, selecting graft techniques, choosing vasodilators, and refining delivery methods, practitioners can tailor their strategies to the individual patient, enhancing the efficacy of coronary revascularization.

Internal Mammary Artery Graft Flow Steal by a Large Dialysis Arteriovenous Fistula Characterized by Electrical Storm

Background: Steal syndrome describes a condition in which a dilated vessel distal to a smaller artery attempts to compensate for decreased blood flow by “stealing” from the smaller artery. Steal syndrome is not uncommon and can be seen in certain physiologic and pathologic states. The classic example is an occluded atherosclerotic coronary artery resulting in a misdirection of blood flow into the open channels that have developed over time resulting in downstream ischemia. Case Report: A 66-year-old male fourteen years post 4-vessel coronary artery bypass grafting using his left internal mammary artery to bypass a stenotic segment of the left anterior descending artery, along with three saphenous venous conduits to the right coronary artery. He also had a stent placement by PCI. He was on dual antiplatelet therapy with aspirin and clopidogrel. An electrophysiology study revealed inducible VF and he underwent implantation of a dual chamber ICD 9 months prior to presentation. He experienced an unprovoked fall at home and a workup revealed the flow volume through the patient’s fistula increased to such a degree that the patient developed a steal syndrome from his left internal mammary artery graft. In addition, went into a state of electrical storm caused by ischemic damage to cardiac tissue distal to the graft. By ligating the fistula, the patient’s steal syndrome resolved and he did not suffer further ventricular arrhythmias. Conclusion: Both coronary bypass grafting and fistula formation are common and necessary interventions and providers should take care to monitor for interactions between these proposed interventions to best serve their patients without causing additional harm. Increased vascular flow through any portion of the body can induce a steal syndrome from an upstream region. Patients who undergo arteriovenous (AV) fistula placement may develop a steal syndrome from ipsilateral bypass grafts.

Transient internal mammary artery graft stenosis on early angiography: navigating pitfalls in hybrid myocardial revascularization.

Left internal mammary artery (LIMA) graft stenoses detected at early coronary angiography may be reversible and consequently prompt unnecessary graft revision. We aim to investigate the frequency, natural course, and clinical significance of internal mammary artery graft stenosis upon early angiography in patients undergoing hybrid myocardial revascularization. In this retrospective sub-study of the Coronary Hybrid Revascularization Study, we compared graft appearance, ie, stenosis degree and flow, on early (in-hospital) and scheduled follow-up coronary angiography after 1 year. We assessed the change in graft patency using the Fitzgibbon classification (grade A: unimpaired runoff; grade B > 50% stenosis; grade O: occlusion), as well as graft association with adverse events (death, myocardial infarction, stroke, and repeat revascularization) at up to 5-year follow-up. We report clinical follow-up data for all 131 patients included in the Coronary Hybrid Revascularization Study. Change in graft patency was analyzed in 86 patients with satisfactory visualization of the LIMA graft on early and follow-up coronary angiography. All LIMA grafts were patent at discharge and follow-up. Twenty-seven of 37 (73%) grade B graft stenoses at early angiography resolved to grade A during follow-up of median 12 months (range, 8-83 months) after surgery. Angiographically significant graft stenoses at early coronary angiography were not associated with adverse clinical outcome up to 5-year follow-up. Our results suggest that the majority of clinically silent LIMA graft stenoses resolve during follow-up and are not associated with adverse clinical outcomes.

The relationship between prognostic nutritional index and long-term mortality in patients undergoing emergency coronary artery bypass graft surgery for acute-ST elevation myocardial infarction.

Malnutrition and the prognosis of coronary artery disease (CAD) are shown to be correlated. The significance of nutritional status has been evaluated in patients with ST elevation myocardial infarction (STEMI), stable CAD, and elective coronary artery bypass graft (CABG) surgery. However, the prognostic impact of poor nutritional status on STEMI patients who underwent emergent CABG is not known. In this study, we aimed to investigate the relationship between nutritional status assessed by the prognostic nutritional index (PNI) and long-term mortality in STEMI patients who underwent emergent CABG. To the best of our knowledge, our study is the first one to evaluate the PNI effect on this specific population. 131 consecutive patients with STEMI who did not qualify for primary percutaneous coronary intervention and required emergent CABG between 2013 and 2018 were included in our study. The study population was divided into two groups: survivors and non-survivors. The PNI was calculated as 10 × serum albumin (g/dL) + 0.005 × total lymphocyte count (per mm3) for both groups, using the preoperative data. The optimal cut-off value was obtained by receiver operating characteristic (ROC) analysis. According to the cut-off value, we investigated the relationship between PNI and long-term mortality. The mean age of the study population was 57.0±10.6. During the median 92.7 (70.0-105.3)-month follow-up, 32 of the 131 patients (24.4%) died. Regression analysis showed a significant association between glucose levels (hazard ratio (HR), 1.007; 95% confidence interval (CI), 1.002-1.012; p=0.011) and PNI (HR, 0.850; 95% CI, 0.787-0.917; p<0.001) and long-term mortality. Accord-ing to the ROC analysis, the cut-off value for PNI to predict all-cause mortality was found to be 44.9, with a sensitivity of 81.3% and a specificity of 89.9%. In addition, age, ejection fraction, glomerular filtration rate, Killip classification, and left anterior descending-left internal mammary artery graft use are significantly associated with long-term all-cause mortality in STEMI patients undergoing emergency CABG. The PNI was significantly associated with long-term mortality in patients with STEMI who underwent emergent CABG. PNI can be used to improve the accuracy of the risk assessment of STEMI patients undergoing emergent CABG.

Percutaneous Coronary Intervention in a Saphenous Vein Graft Failure: A Case Report

Abstract: Recent published data from the Society of Thoracic Surgery (STS) national database displayed that among patients aged &gt;65 years old who survived following an initial coronary artery bypass graft (CABG) operation, rates of repeat revascularization at 1, 5, 10, and 18 years were 2%, 8%, 16%, and 25%, respectively. The most preferred mode of revascularization was percutaneous coronary intervention (PCI). While remain the most frequently used conduits beside left internal mammary artery (LIMA), saphenous vein grafts (SVGs) have high failure rates. Percutaneous coronary intervention in SVGs is associated with an increased risk of distal coronary embolization, commonly resulting in periprocedural MI. We reported a 79-year-old male patient admitted due to progressive symptoms of chronic coronary syndrome. The patient had a history of hypertension and a CABG surgery in 2012. Electrocardiogram showed ischemia and old myocardial infarction (OMI) in inferior leads as well as poor R wave progression in the precordial leads. Transthoracic echocardiogram displayed a normal ejection fraction but impaired left ventricular (LV) diastolic relaxation. Diagnostic coronary angiography revealed a 70% tubular stenosis in proximal part of SVG supplying posterior descending artery, patent LIMA graft to left anterior descending artery, and complex lesion on native vessel (chronic total occlusion in mid right coronary artery). Implantation of drug eluting stent in SVG-posterior descending artery was performed. Direct-stenting PCI technique using undersized-stent was done to prevent any complications. In conclusion, despite the high risk of complications, vein graft intervention was successfully performed without any complications. Since the high rates of in-stent restenosis following PCI in SVGs, long-term dual antiplatelet therapy should be commenced in this patient. Keywords: saphenous vein graft; vein graft intervention; percutaneous coronary intervention

Multi-slice CT coronary angiography versus invasive coronary angiography in the assessment of graft patency after coronary artery bypasses graft surgery

BackgroundThe long-term patency of arterial and venous grafts is crucial for the success of CABG. This study was designed to investigate graft patency using 128-slice coronary computed tomography angiography (CCTA) and compared the results with those obtained using invasive coronary angiography (ICA). In this observational cross-sectional study, we included 40 symptomatic post-CABG patients underwent CCTA and ICA within the same month.ResultsFifty-five percent were aged more than 60 years, and 80% were males. 67.5% had diabetes, 90% had hypertension, and 30% were smokers. Mean body mass index was 28.89 ± 5.17 kg/m2. Mean duration since CABG was 5.25 ± 4.04 years. In total, 124 native vessels and 97 grafts were assessed using CCTA and ICA. CCTA delineated 8 non-cannulated venous grafts and 6 non-cannulated left internal mammary artery grafts. CCTA required a significantly lower radiation dose (1165.77 ± 123.54 vs. 47,589.78 ± 6967.53, p < 0.001).ConclusionCCTA can be as accurate as ICA in assessing bypass grafts with less radiation dose, providing a non-invasive reliable tool for evaluation.

Radial artery graft in coronary artery bypass surgery 1 week to 1 year postoperation.

The actual patency rate of the radial artery (RA) grafts 1 week and 1 year after coronary artery bypass grafting (CABG) has not been extensively reported on. We used coronary computed tomography angiography (CCTA) to evaluate the patency rate of RA grafts and compared it with that of saphenous vein (SV) grafts. In this observational cohort study, 80 patients who underwent urgent or elective CABG with RA and SV grafts at Ruijin Hospital from August 2019 to June 2021 were included. Follow-up CCTA scans were completed about 1 year postoperation in the out-patient clinic. We graded the grafts into four classes: A, excellent; B, graft diameter <50% of target coronary artery; O, occluded; and S, string sign. Both S and O were defined as graft failure. The patients' mean age was 58.48±8.06 years, and 87.5% (70/80) of the patients were male. The 1-week patency rate of the left internal mammary artery (LIMA), RA, and SV grafts were 98.7% (75/76), 76.3% (61/80), and 93.8% (75/80), respectively. At 1 year, the patency rate of the LIMA, RA, and SV grafts were 97.4% (74/76), 80.0% (64/80), and 81.3% (65/80), respectively. The RA graft patency rate was lower than was the SV graft patency rate perioperatively [relative risk (RR): 0.918; 95% confidence interval (CI): 0.852-0.990; P=0.007]. Moreover, 63.6% (7/11) of RA grafts graded S and 25.0% (2/8) of RA grafts graded O were defined as patent (graded A or B) at 1 year postoperation. Compared with SV grafts, more RA grafts improved (RA: 12/80, 15.0%; SV: 0%) and fewer RA grafts deteriorated (RV: 10/80, 12.5%; SV: 19/80, 23.8%) from 1 week to 1 year (P=0.001). The patency rate of the 2 types of grafts became similar at 1 year postoperation (RR: 0.560; 95% CI: 0.113-2.781; P>0.99). RA grafts had a lower patency rate than did SV grafts 1 week after operation. However, because of the "revival" phenomena and lower attrition rate, the patency rate of the two kinds of grafts did not show any significant difference at 1 year.

Feasibility and accuracy of real-time 3D-holographic graft length measurements.

Mixed reality (MR) holograms can display high-definition images while preserving the user's situational awareness. New MR software can measure 3D objects with gestures and voice commands; however, these measurements have not been validated. We aimed to assess the feasibility and accuracy of using 3D holograms for measuring the length of coronary artery bypass grafts. An independent core lab analyzed follow-up computer tomography coronary angiograms performed 30 days after coronary artery bypass grafting in 30 consecutive cases enrolled in the FASTTRACK CABG trial. Two analysts, blinded to clinical information, performed holographic reconstruction and measurements using the CarnaLife Holo software (Medapp, Krakow, Poland). Inter-observer agreement was assessed in the first 20 cases. Another analyst performed the validation measurements using the CardIQ W8 CT system (GE Healthcare, Milwaukee, Wisconsin). Seventy grafts (30 left internal mammary artery grafts, 31 saphenous vein grafts, and 9 right internal mammary artery grafts) were measured. Holographic measurements were feasible in 97.1% of grafts and took 3 minutes 36 s ± 50.74 s per case. There was an excellent inter-observer agreement [interclass correlation coefficient (ICC) 0.99 (0.97-0.99)]. There was no significant difference between the total graft length on hologram and CT [187.5 mm (157.7-211.4) vs. 183.1 mm (156.8-206.1), P = 0.50], respectively. Hologram and CT measurements are highly correlated (r = 0.97, P < 0.001) with an excellent agreement [ICC 0.98 (0.97-0.99)]. Real-time holographic measurements are feasible, quick, and accurate even for tortuous bypass grafts. This new methodology can empower clinicians to visualize and measure 3D images by themselves and may provide insights for procedural strategy.

Feasibility and accuracy of real-time 3D-holographic graft length measurement, a sub-study of the FAST-TRACK CABG trial

Abstract Background 3D Hologram is an emerging tool for intuitively manipulating and visualizing CT images. Mixed reality (MR) technology can display high-definition 3D holograms while preserving situational awareness. The new MR software offers the possibility to measure 3D objects using hand gestures and voice commands. However, these measurements made on 3D holograms have not been validated. Purpose We aimed to assess the feasibility and accuracy of using CT-derived 3D holograms for bypass graft length measurement. Methods Twenty-seven consecutive cases in the FAST TRACK CABG trial were included. The post-operative CT images performed at 30 days follow-up were analyzed in an independent core lab. Two analysts blinded to clinical information performed Holographic reconstruction and measurement using the CanaLife Holo software (Medapp, Krakow, Poland). (Figure 1) Inter-observer agreement was assessed in the first 20 cases. Another analyst with full access to clinical information performed the validation measurements on the CardIQ W8 system (GE Healthcare, Milwaukee, Wisconsin). (Figure 1) Results A total of 62 grafts (27 left internal mammary artery grafts, 27 saphenous vein grafts, and 8 right internal mammary artery grafts) were measured. There was an excellent inter-observer agreement between the analysts in the first 47 grafts analyzed (interclass correlation 0.9879 [0.9783-0.9933]). (Figure 2A, 2B) On average, holographic reconstruction and measurement of a case took 3 minutes and 36 seconds± 50.74 seconds compared to around 10 minutes per vessel on the traditional CT system. There was no significant difference between the graft length measured by hologram and CT (188.59±51.63 mm vs. 183.95±50.93 mm, p=0.616). The length measured by hologram and CT were similar across different graft types. The measurements of hologram and CT are highly correlated (r=0.973, p &amp;lt;0.001) with an excellent agreement (interclass correlation 0.9928 [0.9880-0.9957]). (Figure2C, 2D) Conclusion Holographic vessel length measurement is feasible, fast, and accurate even for tortuous coronary bypass grafts. This new methodology can empower surgeons to visualize and measure the results of their work by themselves and may provide insights for procedure evaluation. 3D Holograms can eventually empower surgeons to plan the precise length of the arterial and venous grafts to be harvested for every individual case.

P27 DOPPLER ULTRASOUND SELECTION AND FOLLOW–UP OF THE INTERNAL MAMMARY ARTERY AS CORONARY GRAFT

Abstract The impact of coronary artery disease (CAD) on all–cause mortality and overall disabilities is well–established. Percutaneous and/or surgical coronary revascularization procedures dramatically reduced the occurrence of adverse cardiovascular events in patients suffering with atherosclerosis. Specifically, guidelines from the European Society of Cardiology on the management of myocardial revascularization promoted coronary artery by–pass graft (CABG) intervention in patients with specific alterations in coronary tree due to higher beneficial effects of this procedure as compared to percutaneous one. Left internal mammary artery (LIMA) is one of the best–performing vessels in CABG procedures due to its location and its own structural characteristics. Nevertheless, non–invasive assessment of its patency is challenging. Doppler Ultrasonography (DU) might perform as a reliable technique for non–invasive evaluation of the patency of LIMA. Data from literature revealed that DU may detect severe (&amp;gt;70%) stenosis of the LIMA graft. In this case, pulsed–wave Doppler might show peak diastolic velocity/peak systolic velocity &amp;lt; 0.5 and diastolic fraction &amp;lt; 50%). Stress test might also be adopted for the evaluation of patency of LIMA through DU. The aim of this narrative review is to evaluate the impact of DU on the evaluation of the patency of LIMA graft in patients who undergo follow–up after CABG intervention. The aim of this narrative review is to evaluate the impact of DU on the evaluation of the patency of LIMA graft in patients who undergo follow–up after CABG intervention.

Interventions in Left Internal Mammary Artery

Left internal mammary artery (LIMA) grafts are the preferred arterial grafts as they are more durable. LIMA grafts can develop stenosis most commonly at the distal anastomotic site and less frequently involve the ostium or body of LIMA. They may occur in the immediate post-operative period due to technical faults or occur several years later. LIMA graft interventions are more challenging because of its long and tortuous course and frequently tend to develop spasm and dissection. It might be the only method of revascularization in some patients and needs to be undertaken on and off. LIMA grafts have been used for retrograde revascularization of chronic total occlusion of native coronary arteries.

Left Axillary Access for Transcatheter Aortic Valve Implantation in a Patient With Two Dependent Internal Mammary Artery Grafts and a Permanent Left-Sided Implanted Pacemaker

Transfemoral access has been established as the gold standard approach for the majority of patients undergoing transcatheter aortic valve implantation (TAVI). However, in cases with anatomical difficulties or severely diffused peripheral arterial disease, alternative vascular access may be considered such as the transaxillary approach. We present the case of a 92-year-old gentleman with exertional dyspnea due to severe symptomatic aortic stenosis and a history of peripheral femoro-femoral bypass surgery, coronary arterial bypass surgery and a permanent dual-chamber left-side implanted pacemaker. Due to the high surgical risk and the severe anatomical difficulties, the method of TAVI using the left axillary approach was opted. A 14-F vascular sheath was inserted with surgical cutdown and with fluoroscopic guidance while small injections of contrast confirmed the non-occlusive position and the patency of the left internal mammary artery (LIMA) graft. A stiff guidewire was used to cross the heavily calcified aortic valve and subsequently was placed into the left ventricle. Balloon aortic valvuloplasty was performed followed by a successful TAVI with no significant aortic regurgitation or paravalvular leak. The patient recuperated uneventfully and was discharged after 72 h. Axillary access for TAVI is a feasible option for high-risk patients with extended peripheral arteriopathy. To our knowledge this is the first case report describing the implantation of a newer type of intra-annular self-expanding valve platform in a nonagenarian patient with severe comorbidities and such a remarkable history of multiple previous interventions in the selected access site. Meticulous upfront strategy planning and efficient collaboration between specialties is of outmost importance in hybrid procedures for favorable clinical outcomes, especially in cases with challenging anatomies.

Abnormal Wall Shear Stress Area is Correlated to Coronary Artery Bypass Graft Remodeling 1 Year After Surgery.

Coronary artery bypass graft surgery is a common intervention for coronary artery disease; however, it suffers from graft failure, and the underlying mechanisms are not fully understood. To better understand the relation between graft hemodynamics and surgical outcomes, we performed computational fluid dynamics simulations with deformable vessel walls in 10 study participants (24 bypass grafts) based on CT and 4D flow MRI one month after surgery to quantify lumen diameter, wall shear stress (WSS), and related hemodynamic measures. A second CT acquisition was performed one year after surgery to quantify lumen remodeling. Compared to venous grafts, left internal mammary artery grafts experienced lower abnormal WSS (< 1Pa) area one month after surgery (13.8 vs. 70.1%, p = 0.001) and less inward lumen remodeling one year after surgery (- 2.4% vs. - 16.1%, p = 0.027). Abnormal WSS area one month post surgery correlated with percent change in graft lumen diameter one year post surgery (p = 0.030). This study shows for the first time prospectively a correlation between abnormal WSS area one month post surgery and graft lumen remodeling 1year post surgery, suggesting that shear-related mechanisms may play a role in post-operative graft remodeling and might help explain differences in failure rates between arterial and venous grafts.

Doppler Ultrasound Selection and Follow-Up of the Internal Mammary Artery as Coronary Graft.

The impact of coronary artery disease (CAD) on all-cause mortality and overall disabilities is well-established. Percutaneous and/or surgical coronary revascularization procedures dramatically reduced the occurrence of adverse cardiovascular events in patients suffering from atherosclerosis. Specifically, guidelines from the European Society of Cardiology on the management of myocardial revascularization promoted coronary artery by-pass graft (CABG) intervention in patients with specific alterations in the coronary tree due to the higher beneficial effects of this procedure as compared to the percutaneous one. The left internal mammary artery (LIMA) is one of the best-performing vessels in CABG procedures due to its location and its own structural characteristics. Nevertheless, the non-invasive assessment of its patency is challenging. Doppler ultrasonography (DU) might perform as a reliable technique for the non-invasive evaluation of the patency of LIMA. Data from the literature revealed that DU may detect severe (&gt;70%) stenosis of the LIMA graft. In this case, pulsed-wave Doppler might show peak diastolic velocity/peak systolic velocity &lt; 0.5 and diastolic fraction &lt; 50%. A stress test might also be adopted for the evaluation of patency of LIMA through DU. The aim of this narrative review is to evaluate the impact of DU on the evaluation of the patency of LIMA graft in patients who undergo follow-up after CABG intervention.

A robotic-assisted hybrid coronary revascularization program: Establishment and early experience in the Middle East.

Hybrid coronary revascularization (HCR) is a technique that merges coronary artery bypass grafting surgery and percutaneous coronary intervention (PCI) approaches for the treatment of multivessel coronary artery disease. The surgical component of the procedure is minimally invasive and can be done using robotic technology that avoids the need for sternotomy. Our objective is to study all patients who underwent robotic-assisted HCR (RHCR) to evaluate the feasibility and safety of the procedure during the establishment phase. This study is a retrospective chart review conducted at King Faisal Specialist Hospital and Research Centre in Jeddah (KFSRC-J). The study focuses on patients who underwent RHCR between July 2018 to December 2020. The study was approved by the institutional review board #2020-103. Robotic-assisted HCR was performed on 78 patients (mean age, 56 years (range, 43-72 years); 89.75% males) during the study phase. Left internal mammary artery grafting was used in all patients. There was no hospital mortality, and the mean hospital and intensive care unit(ICU) stay were 5.8 and 1.4 days, respectively. We found that 93.6% of the patients had no blood transfusion. There were no major adverse cardiac events (MACE) and perioperative MI recorded. There was a 3.8% rate of postoperative complications. The percentage of surgeries converted to conventional and re-exploration for bleeding were 1.2% and 2.6%, respectively. The average operation time was 164 min. This study emphasizes on the safety and effectiveness of RHCR in treating patients with multivessel coronary artery disease. Moreover, robotic-assisted hybrid coronary revascularization offers an alternative, functionally complete revascularization option to a selected group of patients with minimal surgical trauma, short hospital and ICU length of stay, quick recovery, and little to no blood transfusion requirement.

Use of papaverine in harvesting internal mammary graft in coronary artery bypass grafting: An update

AbstractThe left internal mammary artery (LIMA) graft is the main arterial graft that is used in coronary artery bypass grafting (CABG). The spasm of LIMA is a complication that frequently occurs while harvesting the LIMA and may lead to morbidity and mortality in patients after CABG. Clinically, papaverine is the most frequently used vasodilator. In this review, we evaluated the administration of papaverine in IMA grafts during CABG. It was shown that administration of papaverine into the LIMA improves the blood flow and abolishes vasospasm of the LIMA. Moreover, the intraluminal and perivascular administrations of papaverine are more effective than topical administration. Higher concentrations of papaverine should be used with caution because it may lead to endothelial damage.

Instantaneous wave free ratio value impact on left internal mammary artery graft patency.

To assess whether instantaneous wave - free ratio (iFR) value is associated with left internal mammary artery (LIMA) graft failure at 12months follow-up post coronary artery bypass graft (CABG). Data suggests bypass to a non-significant left anterior descending artery (LAD) lesion due to visual over-estimation may lead to LIMA graft failure. Implementing iFR may result in better arterial graft patency. In iCABG (iFR guided CABG) study patients planned to undergo an isolated CABG procedure was prospectively enrolled and iFR was performed for LAD. Coronary computed tomography angiography was performed at 2 and 12months follow-up. The primary endpoint of this study was to determine the rate of LIMA graft occlusion or hypoperfusion at 2 and 12-months follow-up. We considered a composite secondary endpoint of Major adverse cardiovascular and cerebrovascular event (MACCE) as a secondary outcome. In total 69 patients were included with no differences regarding age, sex and risk factors. At 2months, 50 of LIMAs with pre-CABG iFR median 0.855 (0.785 - 0.892) were patent. Hypoperfusion was found in 8 LIMAs (median iFR 0.88 (0.842 - 0.90)). While, 7 LIMAs (median iFR 0.91 (0.88 - 0.96)) were occluded (p = 0.04). At 12months, when iFR of LAD was >0.85: just 12 (31.6% out of all patent LIMAS) grafts were patent and 24 (100.0% out of all hypoperfused/occluded) grafts were hypoperfused or occluded (p < 0.001). In terms of MACCE, no difference (p = 1.0) was found between all 3 groups divided according to iFR value. Instantaneous wave - free ratio value above 0.85 in LAD is a powerful tool predicting LIMA graft failure at 1-year follow up period.