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Background: The use of the left internal thoracic artery (LITA) is the gold standard in coronary artery bypass graft surgery (CABG). Multiarterial grafting for CABG is being increasingly emphasized. This study aimed to resolve the utility of the right internal thoracic artery (RITA) for multiple CABG as "free" RITA and described new evidence., Methods: One hundred sixty-three patients received solo CABG with bilateral internal thoracic arteries between 2005 and 2018. The RITA was used as in situ RITA, group A (n = 62), and the composite graft created with saphenous vein graft (SVG), group B (n = 101). The patency rate and graft size of the composite free RITA and SVG were examined by coronary computed tomography angiography., Results: The average number of distal anastomoses per patient was 3.4 ± 1.0 in group A, and 4.2 ± 1.1 in group B (P < .001). The sequential grafting with free RITA was in 86 patients. The patency rate of both LITA and RITA was similar in both groups. In group B, 40 patients received late computed tomography angiography at a mean of 46 months (range, 17 to 175). The late patency rate was 95.1% in LITA and 96.9% in free RITA. The diameter of free RITA increased from 2.06 ± 0.34 mm to 2.37 ± 0.23 mm (P = .036); that of in situ LITA increased from 2.08 ± 0.51 mm to 2.44 ± 0.49 mm (P = .047); and that of composite SVG decreased from 4.1 ± 0.9 mm to 2.6 ± 0.7 mm (P < .001)., Conclusions: Multiple bypass grafting can be sufficiently achieved with LITA and free RITA. The growth potential of free RITA and in situ LITA might play the important role of expected long-term patency., (Copyright © 2021 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Objectives: We compared 10-year graft patency rates and long-term clinical outcomes after off-pump coronary artery bypass grafting using the saphenous vein composite grafts based on the left internal thoracic artery with those using total arterial composite grafts., Methods: A total of 483 patients who underwent off-pump coronary artery bypass grafting using composite grafts based on the left internal thoracic artery were included. The saphenous vein was used as a second (connected to the left internal thoracic artery; n = 63) or a third (connected to the second arterial graft; n = 40) composite graft in 103 patients (SV group); total arterial composite grafting was performed in 380 patients (ART group). A propensity score-matched analysis was used to match the SV group to the ART group (n = 103 patients in each). The median follow-up duration was 128 (97-139) months., Results: There were no differences in operative mortality and postoperative complication rates between the 2 matched groups. Propensity score-matched analyses showed no differences in the overall survival and freedom from cardiac death rates between the 2 groups (P = .369 and P = .206, respectively) up to 12 years after surgery. Freedom rates from reintervention and major adverse cardiac and cerebrovascular events were also similar between the 2 matched groups (P = .695 and P = .758, respectively) up to 12 years after surgery. Generalized mixed-effects models showed that the 2 matched groups demonstrated no differences in overall and composite graft patency rates during 10 years after surgery (P = .568 and P = .702, respectively)., Conclusions: The saphenous vein composite grafts were equivalent to arterial composite grafts in terms of 10-year graft patency and long-term clinical outcomes., (Copyright © 2020 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Fueled by the global surge in aging, atherosclerotic cardiovascular disease reached pandemic dimensions putting affected individuals at enhanced risk of myocardial infarction, stroke, and premature death. Atherosclerosis is a systemic disease driven by a wide spectrum of factors, including cholesterol, pressure, and disturbed flow. Although all arterial beds encounter a similar atherogenic milieu, the development of atheromatous lesions occurs discontinuously across the vascular system. Indeed, the internal mammary artery possesses unique biological properties that confer protection to intimal growth and atherosclerotic plaque formation, thus making it a conduit of choice for coronary artery bypass grafting. Its endothelium abundantly expresses nitric oxide synthase and shows accentuated nitric oxide release, while its vascular smooth muscle cells exhibit reduced tissue factor expression, high tPA (tissue-type plasminogen activator) production and blunted migration and proliferation, which may collectively mitigate intimal thickening and ultimately the evolution of atheromatous plaques. We aim here to provide insights into the anatomy, physiology, cellular, and molecular aspects of the internal mammary artery thereby elucidating its remarkable resistance to atherogenesis. We propose a change in perspective from risk to resilience to decipher mechanisms of atheroresistance and eventually identification of novel therapeutic targets presently not addressed by currently available remedies.

Introduction: Left internal mammary artery (LIMA) grafts should be used in patients undergoing CABG. No other procedure results in patency equivalent to that of the left anterior descending coronary artery (LAD)-LIMA bypass graft. The CHA2DS2-Vasc-HS scoring system can be used to successfully predict CAD severity in stable CAD patients. We aimed to investigate the relationship between LIMA flow and the CHA2DS2-Vasc-HS score., Methods: A total of 684 patients, who underwent CABG surgery, were included in this study. Previous history of bypass surgery, emergency operations, patients with Leriche syndrome and patients with severe obstructive pulmonary and subclavian artery disease were excluded from our study. Patients with a LIMA flow that was suitable for bypass grafting, as determined during the intraoperative evaluation, were included in the low LIMA flow group, and the CHA2DS2-Vasc-HS score was calculated for all patients., Results: Patients in the low LIMA flow group (Group 1) were older. The CHA2DS2-Vasc-HS score (P < 0.001), presence of mild or moderate COPD (P = 0.022), number of severely diseased vessels (P = 0.036), and BMI (P < 0.001) were independent predictors of poor LIMA flow. The cutoff value of the CHA2DS2-VASc-HS score for the prediction of poor LIMA flow was >5.5, with a sensitivity of 92.9% and specificity of 83.4% (AUC: 0.938, 95% Cl: 0.906 - 0.970, P < 0.001)., Conclusion: A preoperative high CHA2DS2-Vasc-HS score can be used to predict low intraoperative LIMA flow. The CHA2DS2-Vasc-HS score is an easy-to-use and reliable estimation method and can be used as an additional preoperative of LIMA flow in patients undergoing CABG due to severe CAD.

Background Several randomized trials have compared the patency of coronary artery bypass conduits. All of the published studies, however, have performed pairwise comparisons and a comprehensive evaluation of the patency rates of all conduits has yet to be published. We set out to investigate the angiographic patency rates of all conduits used in coronary bypass surgery by performing a network meta-analysis of the current available randomized evidence. Methods and Results A systematic literature search was conducted for randomized controlled trials comparing the angiographic patency rate of the conventionally harvested saphenous vein, the no-touch saphenous vein, the radial artery (RA), the right internal thoracic artery, or the gastroepiploic artery. The primary outcome was graft occlusion. A total of 4160 studies were retrieved of which 14 were included with 3651 grafts analyzed. The weighted mean angiographic follow-up was 5.1 years. Compared with the conventionally harvested saphenous vein, both the RA (incidence rate ratio [IRR] 0.54; 95% CI, 0.35-0.82) and the no-touch saphenous vein (IRR 0.55; 95% CI, 0.39-0.78) were associated with lower graft occlusion. The RA ranked as the best conduit (rank score for RA 0.87 versus 0.85 for no-touch saphenous vein, 0.23 for right internal thoracic artery, 0.29 for gastroepiploic artery, and 0.25 for the conventionally harvested saphenous vein). Conclusions Compared with the conventionally harvested saphenous vein, only the RA and no-touch saphenous vein grafts are associated with significantly lower graft occlusion rates. The RA ranks as the best conduit. Registration URL: https://www.crd.york.ac.uk/prospero; Unique identifier: CRD42020164492.

Purpose: The left internal mammary artery (LIMA) is the preferred graft for coronary artery bypass grafting, but the reasoning for LIMA occlusion is unclear. We sought to examine whether the wall shear stress (WSS) values of LIMA grafts during the perioperative period reflected the 1-year patency by using combining computational fluid dynamics (CFD) and coronary computed tomography angiography (CCTA) images., Methods: CCTA was performed in 233 patients with LIMA graft perioperatively and 1 year later from October 2014 to May 2017. LIMA occlusion was detected in six patients at the 1-year follow-up CCTA. Two patients were excluded due to poor imaging quality. The remaining four patients were enrolled as occlusive (OCC) group, and eight patients with patent LIMA were recruited as patent (PAT) group. The WSS values of LIMA during perioperative period were calculated. LIMA graft was artificially divided into three even segments, proximal (pLIMA), middle (mLIMA) and distal (dLIMA) segments. The independent samples t -test and the Student-Newman-Keuls test were used., Results: The WSS values of dLIMA were significantly higher in the PAT group than in the OCC group (4.43 vs. 2.56, p  < 0.05). The WSS values of dLIMA in the PAT group were significantly higher than pLIMA, which was absent in the OCC group., Conclusions: A higher WSS value of the distal segment of LIMA and a higher WSS value of the distal segment compared with the proximal segment of LIMA in the PAT were observed; this tendency might be helpful in predicting the 1-year patency of LIMA., Competing Interests: None declared., (Thieme. All rights reserved.)

Background: The method of coronary-coronary bypass grafting was described in 1987 but has not been widely used, and there are only a few studies that report good short-term and mid-term results as well as some individual cases of long-term follow-up. In our medical institution, we carried out an analysis of the long-term results of coronary-coronary bypass grafting, which are presented in this study., Methods: This was a retrospective single-center study on 95 patients who underwent coronary-coronary bypass grafting as a supplement to the standard coronary bypass grafting procedure. All patients underwent angiographic assessment of the coronary bypass grafts during the long-term follow-up period. The observation period was up to 123 months. Angiographic assessment of 109 coronary-coronary grafts was carried out., Results: Twelve (7.6%) arterial and 11 (19.3%) venous conduits were found to be occluded, and 8 (10.3%) arterial and 10 (31.3%) venous coronary-coronary grafts were occluded during the observation period., Conclusion: Arterial coronary-coronary artery bypass grafting represents an alternative technique that allows complete myocardial revascularization.

Background: Where each patient has all three conduits of internal mammary artery (IMA), saphenous vein graft (SVG) and radial artery (RA), most confounders affecting comparison between conduits can be mitigated. Additionally, since SVG progressively fails over time, restricting patient angiography to the late period only can mitigate against early SVG patency that may have occluded in the late period., Methods: Research protocol driven conventional angiography was performed for patients with at least one of each conduit of IMA, RA and SVG and a minimum of 7 years postoperative. The primary analysis was perfect patency and secondary analysis was overall patency including angiographic evidence of conduit lumen irregularity from conduit atheroma. Multivariable generalized linear mixed model (GLMM) was used. Patency excluded occluded or "string sign" conduits. Perfect patency was present in patent grafts if there was no lumen irregularity., Results: Fifty patients underwent coronary angiography at overall duration postoperative 13.1 ± 2.9, and age 74.3 ± 7.0 years. Of 196 anastomoses, IMA 62, RA 77 and SVG 57. Most IMA were to the left anterior descending territory and most RA and SVG were to the circumflex and right coronary territories. Perfect patency RA 92.2% was not different to IMA 96.8%, P = 0.309; and both were significantly better than SVG 17.5%, P < 0.001. Patency RA 93.5% was also not different to IMA 96.8%, P = 0.169, and both arterial conduits were significantly higher than SVG 82.5%, P = 0.029. Grafting according to coronary territory was not significant for perfect patency, P = 0.997 and patency P = 0.289. Coronary stenosis predicted perfect patency for RA only, P = 0.030 and for patency, RA, P = 0.007, and SVG, P = 0.032. When both arterial conduits were combined, perfect patency, P < 0.001, and patency, P = 0.017, were superior to SVG., Conclusions: All but one patent internal mammary artery or radial artery grafts had perfect patency and had superior perfect patency and overall patency compared to saphenous vein grafts.

Coronary artery disease (CAD) remains one of the most important causes of morbidity and mortality worldwide, and the availability of percutaneous or surgical revascularization procedures significantly improves survival. However, both strategies are daunted by complications which limit long-term effectiveness. In-stent restenosis (ISR) is a major drawback for intracoronary stenting, while graft failure is the limiting factor for coronary artery bypass graft surgery (CABG), especially using veins. Conversely, internal thoracic artery (ITA) is known to maintain long-term patency in CABG. Understanding the biology and pathophysiology of ISR and vein graft failure (VGF) and mechanisms behind ITA resistance to failure is crucial to combat these complications in CAD treatment. This review intends to provide an overview of the biological mechanisms underlying stent and VGF and of the potential therapeutic strategy to prevent these complications. Interestingly, despite being different modalities of revascularization, mechanisms of failure of stent and saphenous vein grafts are very similar from the biological standpoint., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)

A best evidence topic was constructed according to a structured protocol. The question addressed was whether the configuration of bilateral internal thoracic arteries (BITAs) influences survival, patency or repeat revascularization in patients undergoing coronary artery bypass grafting. Five hundred and seventy-one papers were found using the reported searches, of which 8 represented the best evidence to answer the clinical question. One systematic review, 4 randomized trials and 3 observational studies were selected. The authors, date, journal, study type, population, main outcome measures and results are tabulated. All 4 prospective randomized trials found no significant difference in graft patency or mortality when comparing Y-graft and in situ configurations. Three of the 4 randomized trials found no difference in major adverse cardiovascular and cerebrovascular events or repeat revascularization at follow-up. An exception was Glineur et al. (Bilateral internal thoracic artery configuration for coronary artery bypass surgery: a prospective randomized trial. Circ Cardiovasc Interv 2016;9:7), who found that the Y-configuration resulted in lower rates of major adverse cardiovascular and cerebrovascular events. All 3 observational studies reviewed found no alteration in survival, cardiac events or repeat revascularization between in situ and Y-graft BITA configurations. One systematic review found similar outcomes with respect to mortality, cardiac events and repeat revascularization with in situ and composite BITA. In summary, existing literature demonstrates no difference in clinical outcomes between composite and in situ graft configurations. Furthermore, the configuration of BITA does not affect mortality, graft patency or repeat revascularization.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether the anterolateral or the inferior wall served as a better location for the 2nd arterial graft in a 3-system coronary artery bypass grafting procedure. In total, more than 1800 papers were found, of which 6 represented the best evidence to answer the clinical question. All papers demonstrated equivalent early postoperative mortality and morbidity. The 3 largest studies comparing bilateral internal thoracic arteries showed no difference in perioperative mortality and morbidity regardless of whether the 2nd internal thoracic artery was used to graft the left or right system. One of these studies, however, showed significant survival benefit for the left-sided group at 8 years, whereas another study showed a reduced patency of right internal thoracic arteries when grafted to the right coronary artery and when used in situ. One study compared radial grafts to the right- and left-sided targets and showed no difference in long-term patency. Another study also reported on the angiographic patency of right internal thoracic arteries. The authors noted a non-significant increase in graft failure when non-left anterior descending arteries were grafted but no difference between circumflex or posterior descending arteries. All studies demonstrated similar or better mid- and long-term outcomes and patency rates when using the 2nd arterial graft to revascularize left-sided targets when compared with the right. However, all outcomes were similar when comparing non-left anterior descending left-sided targets with non-right coronary artery right-sided targets. Therefore, the right coronary artery itself should probably be avoided as the 2nd arterial target.

Background: The left internal thoracic artery (LITA) is the most commonly used arterial bypass conduit in coronary artery bypass graft (CABG) patients and inadequate LITA flow can result in an increase in morbidity and mortality. In this study, we evaluated the effect of excision of the distal spasmodic segment of the LITA on the free flow in CABG patients., Methods: This study consisted of 47 patients who underwent elective CABG performed with or without other cardiac surgery, between July 2015 and December 2015. Excised LITA length was shorter than 15mm in group 1, between 15mm and 30mm in group 2 and longer than 30mm in group 3. Left ITA free flow was measured for 60seconds into a container before and after the distal LITA excision. The inter-measurement differences were calculated for the three groups. Thereafter, the comparison was performed in terms of free flow difference amongst the three groups., Results: The mean difference of LITA free flow was 27.6±22.7ml/minute in group 1, 35.4±26.7ml/minute in group 2, and 52.6±26.1ml/minute in group 3. There were significant differences in terms of free flow difference between the groups (p=0.008). Also, differences were statistically significant in group 1 versus group 3 (p=0.003) and group 2 versus group 3 (p=0.038) in the intergroup comparisons., Conclusions: The distal part of the LITA has more spasmodic potential than other segments. This spasm may result in low flow of LITA grafts. Therefore, an as long as possible excision of the distal LITA segment may be required to avoid the spasmodic effect., (Copyright © 2017 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.)

Nitroglycerin is commonly used as an antispasmodic for treating spasm of coronary artery bypass grafts. This study investigated whether the presence of renal failure affects reactivity to nitroglycerin in internal thoracic arteries obtained from patients undergoing coronary bypass surgery. The patients were divided into three groups according to estimated glomerular filtration rate (eGFR, mL/min/1.73 m 2 ): without renal failure (60 ≤ eGFR, n = 13), with moderate renal failure (30 ≤ eGFR < 60, n = 10), and with severe renal failure (eGFR < 30, n = 10). Organ chamber technique was used to evaluate concentration-related responses of isolated internal thoracic arteries to vasodilators. Nitroglycerin induced a concentration-dependent relaxation, which was significantly augmented in patients with severe but not moderate renal failure than in those without renal failure. In addition, there was a negative correlation between eGFR and the relaxant efficacy of nitroglycerin (P = 0.016). On the other hand, relaxant responses to BAY 60-2770 (which enhances cGMP generation as with nitroglycerin) were similar among three grades of renal function. An inverse relationship of eGFR to the relaxant efficacy of BAY 60-2770 was not observed, either (P = 0.314). These findings suggest that severe renal failure specifically potentiates nitroglycerin-induced relaxation in internal thoracic artery grafts.

Background: The long-term benefits of a third arterial conduit to the right circulation in triple-vessel disease remain debatable. This retrospective, single-center, propensity-matched study investigates the impact of a third arterial conduit to the right circulation on early and intermediate survival after coronary artery bypass grafting., Methods: Data were retrospectively collected from 2004 to 2014 for all surgical revascularizations for triple-vessel disease with at least 2 arterial conduits to the left circulation and a third arterial or venous conduit to the right circulation. A total of 167 pairs were propensity matched to arterial versus venous third conduit to right circulation. Hazard functions were obtained with Cox multivariate regression and Kaplan-Meier survival curves were compared between the matched cohorts., Results: Extracardiac arteriopathy, logistic euroSCORE, and left main stem disease were significant predictors of adverse survival. A third arterial conduit to the right circulation was not a significant predictor of improved survival in multivariate analysis (HR, 0.72; 95% CI, 0.34-1.55; P = .411). 30-day mortality was 0.6% in both groups. There was no significant difference in early or intermediate survival in the propensity-matched groups (venous vs arterial, 99.2% vs 99.2%; P = 1.000 at 1 year; 85.2% vs 88.8%; P = .248 at 5 years and 69.2% vs 88.8%; P = .297 at 7 years) CONCLUSIONS: The use of a third arterial versus a venous conduit to the right circulation does not improve early or intermediate survival up to 7 years in triple-vessel coronary artery disease in this study. Longer follow-up and larger cohorts may be needed for differences to emerge., (Copyright © 2017 The American Association for Thoracic Surgery. All rights reserved.)

Background: Endothelial shear stress (ESS) has been suggested as a factor affecting atherosclerosis and remodeling of native vessels and bypass conduits. We compared ESS levels of internal thoracic artery (ITA) and saphenous vein (SV) composite grafts intraoperatively and 1 year after coronary artery bypass grafting (CABG)., Methods: Intraoperative ESS was calculated by measuring flow volumes and diameters of proximal and distal ITAs and SV conduits in 23 patients who received SV Y-composite grafts based on the in situ left ITA. Early (1.2 ± 0.5 days) and 1-year (12.9 ± 1.1 months) postoperative angiograms were performed in 23 and 15 patients, respectively. An intragraft Doppler-guidewire study for ESS measurement was performed in 6 patients during 1-year angiography., Results: Intraoperative diameters of proximal and distal ITAs and SV conduits were 2.0 ± 0.2 mm, 1.8 ± 0.3 mm, and 3.2 ± 0.4 mm, respectively. ESS levels were significantly different between them (41.0 ± 21.0, 28.4 ± 25.2, and 4.3 ± 3.0 dyne/cm 2 , respectively). Proximal and distal ITA diameters increased significantly on early angiograms and remained unchanged, but SV diameter increased to 3.7 mm (95% confidence interval, 3.5 to 4.0 mm; p < 0.001) on the early angiogram and decreased to 2.9 mm (95% confidence interval, 2.7 to 3.2 mm; p < 0.001) at 1 year. Significant correlations were found between the initial ESS and proportional changes in conduit diameters during postoperative year 1. SV ESS increased in all 6 patients at 1 year, with no significant differences in ESS levels between the 3 conduits (29.9 ± 7.9, 28.8 ± 7.9, and 21.6 ± 16.3 dyne/cm 2 , respectively)., Conclusions: Initial ESS appears to be associated with proportional changes in conduit diameters in the first year after CABG. ESS values of SV composite grafts were similar to left ITA conduits 1 year after CABG., (Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

This study aimed to evaluate the feasibility and the mid-term efficacy of an in situ skeletonized right internal mammary artery (IMA) bypass grafting to a left anterior descending artery (LAD), and to determine risk factors for IMA graft failure in a single-center study.From January 2012 to December 2015, 189 patients (173 males, 50.6 ± 6.0 years old) undergoing first isolated coronary artery bypass grafting surgery with the in situ skeletonized right IMA grafting to the LAD were included in this study. Baseline characteristics, peroperative data, and follow-up outcomes were investigated and analyzed.The length of the in situ skeletonized right IMA grafts was 18.6 ± 1.2 cm (17.0-22.0 cm). Intraoperative graft flow of the in situ skeletonized right IMA grafting to LAD was 42 ± 9 mL/minute (18-72 mL/minute) associated with measured pulsatility index of 0.8-4.3. In-hospital mortality was 0.5%. Postoperative morbidity included acute myocardial infarction (0.5%), stroke (0.5%), and deep sternal wound infections (1.1%). The mid-term survival was 97.2% and the incidence of repeat revascularization was 0.6%. The patency rate of the in situ skeletonized right IMA grafting to the LAD was 97.1% by computed tomography angiography examination during the follow-up period of 23.2 ± 9.7 months. Additionally, logistic regression analysis showed that intraoperative graft flow had an independent influence on the risk of the mid-term right IMA graft failure.The strategy of the in situ skeletonized right IMA grafting to the LAD is feasible and effective. Intraoperative graft flow was an independent risk factor for the mid-term right IMA graft failure.

Background and Aims: Obesity is a risk factor for endothelial dysfunction and atherosclerosis. However, perivascular adipose tissue can release adipokines and other unknown adipose-derived relaxing factors. Therefore, we investigated the impact of obesity on vascular function and expression of genes in perivascular adipose tissue from internal mammary arteries of patients with coronary artery disease undergoing coronary artery bypass grafting., Methods: The vessel function was compared between groups of patients with a body-mass index (BMI) between 25 and 30 kg/m 2 . The groups did not differ in age, gender (males), and ejection fraction. Vascular segments of internal mammary arteries were examined in a Mulvany myograph. Following preconstriction with noradrenaline, dose-response curves were assessed for relaxation with acetylcholine and sodium nitroprusside., Results: Maximum contraction in response to potassium and noradrenaline was increased in obese patients with a BMI >30 kg/m 2 . EC50 of endothelium-dependent relaxation was impaired in patients with a BMI above 25, but below 30 kg/m 2 . Sodium nitroprusside-mediated maximal relaxation was not different between study groups. Integrin alpha X chain (ITGAX/CD11c) and macrophage mannose receptor (MRC1/CD206) expression was reduced in perivascular adipose tissue of patients with a BMI above 30 kg/m 2 , while adiponectin (ADPQ) expression was increased in the same tissue., Conclusion: Our data suggest a partially reduced endothelial function in internal mammary arteries of adipose patients with a BMI between 25 and 30 kg/m 2 undergoing coronary artery bypass grafting surgery. Increased adiponectin expression in perivascular tissue might contribute to maintenance of endothelial function in obese patients with a BMI above 30 kg/m 2 ., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Objectives: This study aimed to examine the effect of off-pump coronary artery bypass grafting (CABG) in patients who underwent revascularization with bilateral internal thoracic arteries (ITAs)., Methods: Between January 2000 and December 2014, 499 patients underwent isolated CABG with bilateral ITAs for complete revascularization of the left coronary system at our institution. On-pump CABG was performed in 137 patients, and off-pump CABG was performed in 362 patients. We retrospectively compared the clinical outcomes and patency of the ITAs., Results: The off-pump group showed less respiratory failure and required a shorter postoperative stay than the on-pump group. The survival probability, freedom from cardiac events and early graft patency were similar in both groups. Five-year patency of the ITA anastomosed to the left anterior descending artery was significantly greater in the on-pump group than in the off-pump group (98.8% vs 91.2%, P = 0.010). The incidence of string change in the off-pump group was higher than that in the on-pump group (P = 0.017). There was no significant difference between the groups in the 5-year patency of the ITA anastomosed to the left circumflex artery (on-pump group: 93.8%, off-pump group: 91.8%; P = 0.46)., Conclusions: The early graft patency and the late patency of the ITA anastomosed to the left circumflex artery between the groups were similar, implying an equivalent quality of anastomoses. However, the patency of the ITA anastomosed to the left anterior descending artery in the off-pump group showed late deterioration, mainly because of string sign development., (© The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Background: The aim of this prospective study was to compare the effect of application of nitroglycerin and verapamil solution (GV) by organ bath technique with other methods of applications and solutions on the free blood flow of LITA. The technique was not described for in situ graft before., Method: The patients were randomly assigned to four groups: group I (n&#95;32, GV solution by organ bath technique), group II (n&#95;30, papaverine solution by organ bath technique), group III (n&#95;29, topical GV solution) or group IV (n&#95;29, topical papaverine solution). In each patient, pedicled LITA was harvested; thereafter applied with the randomized different methods and solutions. The free flow from the distal end of the divided LITA was measured for 15s under controlled hemodynamic conditions after harvesting (Flow 1). The flow of LITA was measured again just prior to anastomosing the conduit (Flow 2)., Result: The mean blood flow in LITA was 56.2±5.0ml/min before application of solutions. After application, the mean blood flow in group I:102.3±7.0ml/min, in group II: 92.7±3.4ml/min, and in group III: 88.6±2.2ml/min and in group IV: 81.4±2.1. Proportional increases in blood flow observed in group I (82.6%)>group II (65.1%)>group III (57.6)>group IV (44.8%) (p<0.05)., Conclusions: GV solution by organ bath technique is effective and superior in comparison to use of papaverine using organ bath technique or topical spray of GV or papaverine solution., (Copyright © 2017 Cardiological Society of India. All rights reserved.)

The procedure of coronary artery bypass grafting continues to be the "gold standard" for patients with multivessel coronary artery disease and left main stenosis due to favourable long-term and consistent outcomes despite the advent of new generations of stents. But the targeted better long-term outcome of surgical revascularization over percutaneous interventions depends on several variables and aspects; one of them is the choice of conduits used to bypass the stenosed arteries. Coronary artery bypass surgery has been studied and debated for decades and the same applies to the selection of grafts. Current data provide significant benefits for patients who receive full arterial revascularization using both internal thoracic arteries and, if applicable, the radial artery. Unfortunately, the use of multiple arterial grafts is still not performed widely despite the evidence of superiority over multiple saphenous vein grafts that are still the most used grafts in cardiovascular procedures. In this review article, we present current trends and evidences for graft selection and give an overview of controversial data regarding the comparison of the radial artery and saphenous vein. Additionally, few words are spelt on alternative conduits.

Objectives: This meta-analysis aims to assess the graft patency quantitatively and statistically., Methods: Eleven observational studies were identified by systematic literature search, incorporating 3311 patients undergoing coronary endarterectomy (CE) + coronary artery bypass graft (CABG) and 3990 undergoing isolated CABG, which were analysed using random-effects modelling. Heterogeneity, quality of scoring and risk of bias were assessed and reangiographic outcomes were documented., Results: Adjunctive CE decreased graft patency [odds ratios = 0.43, 95% confidence interval [0.29-0.63], z  = 4.33, P  < 0.0001] with moderate heterogeneity, while the baseline demographics differed considerably., Conclusions: Whether CE remains a viable option to CABG requires novel studies collecting corresponding data from bench to bedside. To achieve satisfactory efficacy, surgeons should carefully weigh possible benefits and adverse effects of CE and prepare the surgical strategy adequately., (© The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Background: The objective of this study is to test the effect of permanent right internal mammary artery device closure on coronary collateral function and myocardial ischemia., Methods and Results: This was a prospective, open-label clinical trial in 50 patients with coronary artery disease. The primary study end point was coronary collateral flow index as obtained during a 1-minute proximal right coronary artery (RCA) and left coronary artery balloon occlusion at baseline before and at follow-up examination 6 weeks after distal right internal mammary artery device closure. Collateral flow index is the ratio between simultaneously recorded mean coronary occlusive pressure divided by mean aortic pressure, both subtracted by central venous pressure. Secondary study end points were fractional flow reserve during vessel patency, the quantitative intracoronary ECG ST-segment elevation, and angina pectoris during the same 1-minute coronary occlusion. Collateral flow index in the untreated RCA and left coronary artery changed from 0.071±0.082 at baseline to 0.132±0.117 ( P <0.0001) at follow-up examination and from 0.106±0.092 to 0.081±0.079 ( P =0.29), respectively. RCA fractional flow reserve increased significantly ( P =0.0029) from baseline to follow-up examination, despite deferral of coronary intervention in all patients. There was a decrease in intracoronary ECG ST-elevation during RCA occlusion from baseline to follow-up examination ( P =0.0015); it did not change in the left coronary artery. Angina pectoris during RCA occlusion tended to occur in fewer patients at follow-up versus baseline examination ( P =0.06)., Conclusions: Permanent right internal mammary artery device closure seems to augment extracardiac ipsilateral coronary supply to the effect of reducing ischemia in the dependent myocardial region., Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02475408., (© 2017 The Authors.)

Background: Harvesting the internal thoracic artery (ITA) with semiskeletonization is an alternative technique between conventional wide pedicle and skeletonization. It is almost as simple as pedicle harvesting; however, it is supposed to provide the advantage of graft flow and length. Since the heart is unique being the only organ which is perfused during diastole, for comparing the intraoperative graft flow characteristics of semiskeletonization and pedicle technique, we used diastolic filling (DF) using transit-time flow measurement as a primary result. The objective of this study is to compare if semiskeletonized ITA has a greater effect on the intraoperative DF of graft flow versus conventional pedicled ITA in coronary artery bypass., Methods: Between July 2015 and May 2016, a prospective evaluation of 60 consecutive patients undergoing coronary artery bypass grafting for left anterior descending artery revascularization were randomized to having semiskeletonized (n = 30) or conventional pedicled (n = 30) ITA graft harvested by the same surgeon. Intraoperative transit-time flows were obtained. The DF of the ITA graft at the end of operation was evaluated in two groups., Results: The intraoperative DF was significantly greater in the semiskeletonized grafts than in the pedicled grafts (70.50 ± 14.15 versus 57.6 ± 19.39%; p = 0.005). No statistical difference was observed comparing quantitative pulsatile flow and pulsatile index at the end of the operation in the two groups. However, the free flow of the conduit during the cardiopulmonary bypass before the anastomosis performed was greater in semiskeletonized group than in pedicled group (94 ± 48.37 versus 56.35 ± 34.90 ml/min; p = 0.003). The total operative time was comparable between two groups (p = 0.092)., Conclusions: Semiskeletonized ITA resulted in superior DF of left anterior descending bypass graft flow as compared with pedicled ITA. It is also provide a greater free flow and length of the graft without the long-delayed operative time., Trial Registration: Trial registration number (Study ID): TCTR20160913002 Date of registration: September 10, 2016.

Endothelial dysfunction and inflammation are key mechanisms of vascular disease. We hypothesised that heterogeneity of monocyte subpopulations may be related to the development of vascular dysfunction in coronary artery disease (CAD). Therefore, we examined the relationships between monocyte subsets (CD14 ++ CD16 - "classical - Mon1", CD14 ++ CD16 + "intermediate - Mon2" and CD14 + CD16 ++ "nonclassical - Mon3"), endothelial function and risk factor profiles in 130 patients with CAD undergoing coronary artery bypass grafting. This allowed for direct nitric oxide (NO) bioavailability assessment using isometric tension studies ex vivo (acetylcholine; ACh- and sodium-nitropruside; SNP-dependent) in segments of internal mammary arteries. The expression of CD14 and CD16 antigens and activation markers were determined in peripheral blood mononuclear cells using flow cytometry. Patients with high CD14 + CD16 ++ "nonclassical" and low CD14 ++ CD16 - "classical" monocytes presented impaired endothelial function. High frequency of CD14 + CD16 ++ "nonclassical" monocytes was associated with increased vascular superoxide production. Furthermore, endothelial dysfunction was associated with higher expression of activation marker CD11c selectively on CD14 + CD16 ++ monocytes. Nonclassical and classical monocyte frequencies remained independent predictors of endothelial dysfunction when major risk factors for atherosclerosis were taken into account (β=0.18 p=0.04 and β=-0.19 p=0.03, respectively). In summary, our data indicate that CD14 + CD16 ++ "nonclassical" monocytes are associated with more advanced vascular dysfunction measured as NO- bioavailability and vascular reactive oxygen species production.

Transit-time flow measurement (TTFM) is a reliable method to check the graft function intraoperatively in coronary surgery. The given parameters are: Mean Graft Flow (MGF); Pulsatility Index (PI) and Insufficiency Ratio (%BF). Some cutoffs of these parameters have been identified as predictors for unfair 1-y clinical outcome: mean graft flow (MGF) less than 20 ml/min and high pulsatility index greater than 5. Other cutoffs have been found as related to postoperative angiography: MGF 15 ml/min or less and pulsatility index at least 3 (sensitivity 94%; specificity 61%); MGF less than 15 ml/min and pulsatility index greater than 3 for left coronary artery or pulsatility index greater than 5 for right coronary artery (sensitivity 96%; specificity 77%); MGF 15 ml/min or less and pulsatility index at least 5.1 left coronary artery (sensitivity 98%; specificity 26%). Hence, with the need to improve the diagnostic accuracy of TTFM, high-resolution epicardic coronary ultrasound module has been added to graft flow evaluation providing 2D ultrasound imaging (either in short-axis or long-axis) and color-flow mapping, allowing an accurate morphological evaluation of body graft and anastomosis. An intraoperative method aimed to verify coronary grafts should be easy to handle, not time consuming, minimally invasive, easily meaningful and relatively cheap; in addition, it should offer objective parameters more than qualitative criteria. We herein report the results of our experience with intraoperative graft verification with TTFM and high-resolution imaging along with a systematic review of the literature in this field with the aim to provide a road map to be followed.

There is a significant variety of vascular conduits options for coronary bypass surgery. Adequate graft selection is the most important factor for the success of the intervention. To ensure durability, permeability, and bypass function, there must be a morphological similarity between the graft and the coronary artery. The objective of this review was to analyze the morphological characteristics of the grafts that are most commonly used in coronary bypass surgery and the coronary arteries that are most frequently occluded. We included clinical information regarding the characteristics that determine the behavior of the grafts and its permeability over time. Currently, the internal thoracic artery is the standard choice for bypass surgery because of the morphological characteristics of the wall that makes less prone to developing atherosclerosis and hyperplasia. The radial and right gastroepiploic arteries are the following second and third best options, respectively. The ulnar artery is the preferred choice when other conduits are not feasible.

Objectives: The present study was designed to evaluate the association between chronic kidney disease and the endothelial function of internal thoracic artery (ITA) grafts in patients undergoing coronary bypass surgery. An isometric tension study was performed in ITA strips obtained during surgery. Concentration-response curves for acetylcholine (ACh) and sodium nitroprusside were constructed in ITA strips partially precontracted with phenylephrine under the inhibition of cyclooxygenase. The integrity of the endothelium was verified histologically by en-face staining of the luminal surface with the use of silver nitrate solution., Results: In endothelium-intact ITA strips, ACh produced a concentration-dependent relaxation in patients with glomerular filtration rate (GFR, mL/min/1.73 m 2 ) > 60. A concentration-dependent relaxation response also was observed in patients with GFR 30 to 60, but it was reduced significantly compared with those with GFR > 60. In both groups, removal of endothelium or treatment with nitric oxide (NO) synthase inhibitors almost abolished the ACh-induced relaxation. On the other hand, in patients with GFR < 30, mild contraction rather than relaxation was induced at a high concentration of ACh, which was modified neither by treatment with NO synthase inhibitors nor by removal of the endothelium. Vasodilator responses to sodium nitroprusside were comparable among the 3 groups. The relaxation of endothelium-intact strips to a peak ACh concentration correlated positively with GFR. This relationship held true in a multiple linear regression model, and interaction terms between GFR and other risk factors were not statistically significant., Conclusions: Endothelial function of ITA grafts to release NO is impaired at the time of surgery in patients with chronic kidney disease., (Copyright © 2016 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Transit time flow measurement (TTFM) is a quality control tool for intraoperative graft evaluation in coronary artery bypass graft (CABG) surgery. A critical review of the literature available using TTFM in CABG surgery is the focus of this article. The main objectives will be to detail precise parameters for flow evaluation, to show limitations of TTFM and to prove its predictive impact on postoperative graft failure rate. Publications listed in the PubMed database were reviewed, searching for intraoperative graft verification in coronary surgery by TTFM, with postoperative imaging follow-up (FU) modality and with a special focus on publications released after European guidelines from 2010. Nine included publications revealed an overall graft failure rate of ∼12%. Mean graft flow had a positive predictive value in the largest study, and cut-offs, of at least 20 ml/min for internal mammary artery (IMA) grafts, therein partially confirming guidelines, and 30-40 ml/min for saphenous venous grafts (SVGs) were proposed. An explicit correlation between graft flow, patency rate and severity of coronary stenosis, by indicating the fractional flow reserve, was found for IMA grafts. Increased pulsatility index and increased systolic reverse flow probably predict worse outcome and may help identifying competitive flow. Diastolic filling, rarely indicated, could not be confirmed as the predictive marker. No significant correlation of TTFM and graft failure rate for radial and other arterial grafts could be found, partially due to the small number of these types of grafts analysed. Larger target vessels and lower postoperative CK-MB levels may predict better graft patency rates. Low sensitivity for TTFM to reliably detect graft failure is certainly a major issue, as found in randomized analyses. However, methodical limitations and varying threshold values for TTFM render a general consensus difficult. Influence of quantity (vessel territory distribution) and quality (myocardial scar) of the graft perfusion area, on TTFM and FU outcome, was not included by anyone and should be part of future research. TTFM is probably not the tool of choice to detect progressive late graft failure of SVG. Peroperative TTFM values should be correlated with one type of conduit, differentiating between early and late graft failure (by applying a uniform, appropriated definition), to precise and confirm threshold values., (© The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Background: The effect of proximal side branches on the patency of the internal thoracic artery (ITA) is controversial. We used echocardiography and Doppler to verify the effect of ligation of branches on the flow and coronary flow reserve (CFR) of the grafted ITA in patients after coronary artery bypass grafting (CABG)., Methods: We prospectively investigated 53 patients with preserved left ventricular ejection fraction (LVEF >50%) who underwent CABG of the ITA. In Group I (25 patients), major branches were ligated during ITA anastomosis to the left anterior descending (LAD) coronary artery, whereas no ligation was performed in Group II (28 patients). Systolic flow (SF), diastolic flow (DF), and total flow (TF = SF + DF) were measured by Doppler echocardiography at the proximal level of the ITA preoperatively, at early postoperative stage, and 6 months after surgery. Dobutamine stress echocardiography (DSE) was performed at 6 months to determine CFR., Results: The ITA flow was predominantly systolic before surgery and diastolic in the postoperative period. We found no differences between the groups in DF. On DSE, SF (19.5±9 mL/min vs 32.7±19 mL/min; P=.003) and TF (79±21 mL/min vs 101±47 mL/min; P=.037) were higher in Group II. There were no differences in CFR (1.9±0.46 vs 2.11±0.56; P=.143)., Conclusion: In patients with preserved LVEF, ligation of major side branches during anastomosis to the LAD does not alter ITA flow or CFR., (© 2016, Wiley Periodicals, Inc.)

Objective: To compare mean per-operative flow capacity between skeletonized and pedicled left internal mammary artery (LIMA) in patients undergoing coronary artery bypass grafting (CABG) surgery., Study Design: Randomized control trial., Place and Duration of Study: Department of Cardiac Surgery, Armed Forces Institute of Cardiology and National Institute of Heart Diseases (AFIC-NIHD), Rawalpindi, Pakistan from February to August, 2013., Methodology: Patients undergoing CABG for coronary artery disease, under 80 years, excluded by the exclusion criteria; and fulfilling the inclusion criteria were randomly assigned to two groups of 70 each. One group underwent skeletonized and the other underwent pedicled technique of LIMAharvesting. Free flow was checked just before anastamosis of each LIMAto the LAD, manually in blood flow in ml per minute during cardiopulmonary bypass by allowing it to bleed into a 100 ml container over 20 seconds. Aspecialized proforma was used to record the age, gender, weight, disease, type of IMA used, and free flow of the IMA. Data was analyzed using SPSS 18., Results: The mean age of the patients was 57.16 years in 40 patients, ranging from 36 to 75 years. Disease pattern analysis showed 5%, 10.7% and 84.3% single, double and triple vessel coronary artery disease, respectively. There was significantly higher free flow in the skeletonized group than the pedicled group (p=0.04)., Conclusion: Skeletonized IMAhad superior flow to pedicled IMAin addition to its traditional proven advantages, which justifies its further use as a conduit for myocardial revascularization.

Background: We compared 5-year graft patency rates and midterm clinical outcomes of saphenous vein (SV) composite grafts with those of total arterial (TA) composite grafts in patients who underwent off-pump coronary artery bypass graft surgery (OPCAB)., Methods: Three hundred sixty-three patients who underwent OPCAB using composite grafts based on the left internal thoracic artery were studied. The SV was used as a second (connected to the left internal thoracic artery) or a third (connected to the second arterial graft) composite graft in 90 patients (SV group); TA composite grafting was performed in 273 patients (TA group). Follow-up was complete in 96.4% of patients (350 of 363), with a median follow-up of 82 months. Five-year graft patency rates and long-term clinical outcomes were compared. A propensity score-matched analysis was also performed to minimize differences in preoperative and intraoperative variables (n = 69 in each group)., Results: There were no differences in operative mortality and postoperative complications between the SV group and TA group. Actuarial 5-year patency rates of the venous and arterial composite grafts were 89.3% and 89.5%, respectively (p = 0.958). Those were also similar between the two propensity score-matched SV and TA groups (90.5% and 89.3%, respectively; p = 0.759). Five-year overall survival and freedom from major adverse cardiac and cerebrovascular events were 88.5% and 85.6%, respectively. Those were similar between the two groups before and after propensity score matching., Conclusions: The SV composite grafts were equivalent to arterial composite grafts in terms of 5-year graft patency rates and midterm clinical outcomes., (Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Mechanical stimuli are key to understanding disease progression and clinically observed differences in failure rates between arterial and venous grafts following coronary artery bypass graft surgery. We quantify biologically relevant mechanical stimuli, not available from standard imaging, in patient-specific simulations incorporating non-invasive clinical data. We couple CFD with closed-loop circulatory physiology models to quantify biologically relevant indices, including wall shear, oscillatory shear, and wall strain. We account for vessel-specific material properties in simulating vessel wall deformation. Wall shear was significantly lower (p = 0.014*) and atheroprone area significantly higher (p = 0.040*) in venous compared to arterial grafts. Wall strain in venous grafts was significantly lower (p = 0.003*) than in arterial grafts while no significant difference was observed in oscillatory shear index. Simulations demonstrate significant differences in mechanical stimuli acting on venous vs. arterial grafts, in line with clinically observed graft failure rates, offering a promising avenue for stratifying patients at risk for graft failure.

Background: Bilateral internal thoracic arteries (BITA) have demonstrated superior patency and improved survival in patients undergoing coronary artery bypass grafting. However, the optimal configuration for BITA utilization and its effect on long-term outcome remains uncertain., Methods and Results: We randomly assigned 304 patients undergoing coronary artery bypass grafting using BITA to either in situ or Y grafting configurations. The primary end point was 3-year angiographic patency. Secondary end points included major adverse cardiac and cerebrovascular events (ie, death from any cause, stroke, myocardial infarction, or repeat revascularization) at 7 years. More coronary targets were able to be revascularized using internal thoracic arteries in patients randomized to Y grafting versus in situ group (3.2±0.8 versus 2.4±0.5 arteries/patient; P<0.01). The primary end point did not show significant differences in graft patency between groups. Secondary end points occurred more frequently in the in situ group (P=0.03), with 7-year rates of 34±10% in the in situ and 25±12% in the Y grafting groups, driven largely by a higher incidence of repeat revascularization in the in situ group (14±4.5% versus 7.4±3.2% at 7 years; P=0.009). There were no significant differences in hospital mortality or morbidity or in late survival, myocardial infarction, or stroke between groups., Conclusions: Three-year systematic angiographic follow-up revealed no significant difference in graft patency between the 2 BITA configurations. However, compared with in situ configuration, the use of BITA in a Y grafting configuration results in lower rates of major adverse cardiovascular and cerebrovascular events at 7 years., Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01666366., (© 2016 The Authors.)

Background: Despite evidence that bilateral internal thoracic arteries (ITAs) improve long-term survival after coronary artery bypass grafting (CABG), uptake of this technique remains low. We directly compared bilateral ITA graft configurations and examined long-term outcomes., Methods: We reviewed 762 patients who underwent CABG using bilateral ITA grafts at our institution between 1997 and 2014. The outcomes were mortality and a composite revascularization end point defined as need for percutaneous coronary intervention or repeat CABG. Adjusted subgroup analyses were performed using propensity score-adjusted Cox proportional hazards modeling., Results: The cohort was divided into 4 groups: in situ (left ITA [LITA] anastomosed to the left anterior descending artery [LAD] with in situ right ITA [RITA] anastomosed to the left coronary circulation [239 patients]); in situ LITA-LAD and in situ RITA-right coronary circulation (239 patients); in situ RITA-LAD with in situ LITA-left coronary circulation (185 patients); and in situ LITA-LAD with a free RITA as a composite graft with inflow from the LITA or a saphenous vein graft (99 patients). Over a median follow-up of 1128 days, there were 47 deaths, 58 late percutaneous coronary interventions, and 7 repeat CABG procedures. Unadjusted Kaplan-Meier analysis revealed a difference in need for repeat revascularization among the 4 groups (log rank P = .049). However, after statistical adjustment, graft configuration was not an independent predictor of repeat revascularization or death., Conclusions: Bilateral ITA graft configuration has no independent effect on need for repeat revascularization or long-term survival. Therefore, the simplest technique, determined by individual patient characteristics, should be selected., (Copyright © 2016. Published by Elsevier Inc.)

The radial artery is increasingly used as a second arterial conduit for myocardial revascularization. However, the radial artery is susceptible to vasospasm, which is thought to be the principal cause of graft failure. The radial artery is harvested as a skeletonized or a non-skeletonized graft, but the effect of different harvesting technique remains unknown. In this study, we compared the early- and mid-term angiographic findings to elucidate its influence on the graft luminal diameter. We harvested 39 radial arteries either as a skeletonized (n = 18) or a non-skeletonized graft (n = 21) using an ultrasonic scalpel. We constructed a composite straight graft by combining a right internal thoracic artery and a radial artery. All the radial artery grafts were sequentially anastomosed to coronary arteries. We measured the diameters of the radial arteries before the operation, within 1 month and 1 year after the operation. At early postoperative period, graft diameter was significantly larger in skeletonized grafts. Graft diameter at the point before the first and the second anastomosis was similar in skeletonized grafts, although that was significantly smaller before the second anastomosis in non-skeletonized grafts. However, 1 year after the operation, the graft diameter was comparable and equally reduced after the first anastomosis in both groups. Skeletonization with an ultrasonic scalpel increases the luminal diameter of the radial artery graft at early postoperative period, which, however, reduces possibly as adaptation to graft flow 1 year after the operation.

Background: Normal endothelial function is a measure of vascular health and dysfunction is a predictor of coronary events. Nitric oxide-mediated coronary artery endothelial function, as assessed by vasomotor reactivity during isometric handgrip exercise (IHE), was recently quantified noninvasively with magnetic resonance imaging (MRI). Because the internal mammary artery (IMA) is often visualized during coronary MRI, we propose the strategy of simultaneously assessing systemic and coronary endothelial function noninvasively by MRI during IHE., Methods and Results: Changes in cross-sectional area and blood flow in the right coronary artery and the IMA in 25 patients with coronary artery disease and 26 healthy subjects during IHE were assessed using 3T MRI. In 8 healthy subjects, a nitric oxide synthase inhibitor was infused to evaluate the role of nitric oxide in the IMA-IHE response. Interobserver IMA-IHE reproducibility was good for cross-sectional area (R=0.91) and blood flow (R=0.91). In healthy subjects, cross-sectional area and blood flow of the IMA increased during IHE, and these responses were significantly attenuated by monomethyl-l-arginine (P<0.01 versus placebo). In patients with coronary artery disease, the right coronary artery did not dilate with IHE, and dilation of the IMA was less than that of the healthy subjects (P=0.01). The blood flow responses of both the right coronary artery and IMA to IHE were also significantly reduced in patients with coronary artery disease., Conclusions: MRI-detected IMA responses to IHE primarily reflect nitric oxide-dependent endothelial function and are reproducible and reduced in patients with coronary artery disease. Endothelial function in both coronary and systemic (IMA) arteries can now be measured noninvasively with the same imaging technique and promises novel insights into systemic and local factors affecting vascular health., (© 2016 American Heart Association, Inc.)

Objectives: Few studies have reported the free right internal thoracic artery (RITA) being used in an aorto-coronary fashion. This study aimed to evaluate the free RITA with modified proximal anastomosis in an aorto-coronary fashion., Methods: Between January 2000 and December 2012, 282 patients underwent coronary artery bypass grafting with bilateral internal thoracic arteries for complete revascularization of the left coronary system at our institution. The left internal thoracic artery (LITA) was anastomosed to the left anterior descending artery (LAD) and the RITA was anastomosed to the left circumflex branches (LCX). The RITA was used as a free graft in 213 patients (free group) and as an in situ graft in 69 patients (in situ group). Proximal anastomosis of the free RITA onto the ascending aorta was performed in two different ways. We compared early and late results and graft patency of the free RITA with those of the in situ RITA retrospectively., Results: The numbers of anastomoses per patient and anastomoses of the RITA were larger in the free group than in the in situ group (P < 0.01). There was no significant difference in postoperative survival between the groups (free group: 93.3% vs in situ group: 90.0%, P = 0.82). The 5-year patency of the free RITA was higher than that of the in situ RITA (97.0 vs 80.3%, P = 0.01). The 5-year patency of the free RITA was comparable with that of the in situ LITA anastomosed to the LAD (97.0 vs 92.9%, P = 0.28)., Conclusions: The free RITA anastomosed to the LCX might have better late patency than the in situ RITA. The free RITA with modified proximal anastomosis in an aorto-coronary fashion enables complete revascularization of the left coronary system with the in situ LITA to the LAD., (© The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Spasm of arterial grafts in coronary artery bypass grafting surgery is still a clinical problem, and refractory spasm can occasionally be lethal. Perioperative spasm in bypass grafts and coronary arteries has been reported in 0.43% of all coronary artery bypass grafting surgery, but this may be an underestimate. Spasm can develop not only in the internal mammary artery but more frequently in the right gastroepiploic and radial artery. The mechanism of spasm can involve many pathways, particularly those involving regulation of the intracellular calcium concentration. Endothelial dysfunction also plays a role in spasm. Depending on the clinical scenario, the possibility of spasm during and after coronary artery bypass grafting should be confirmed by angiography. If present, immediate intraluminal injection of vasodilators is often effective, although other procedures such as an intraaortic balloon pump or extracorporeal membrane oxygenation may also become necessary to salvage the patient. Prevention of spasm involves many considerations, and the principles are discussed in this review article., (Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

A 57-year-old man underwent multiple-arterial revascularization including a sequential left internal mammary artery graft to the diagonal branch and left anterior descending coronary artery. Twenty-one months later, repeat angiography due to a new onset of chest discomfort confirmed string sign and nonfunctional proximal left internal mammary artery, and antegrade filling of the distal leg of the sequential graft and the left anterior descending artery through the diagonal branch. This is a known but uncommon angiographic finding that confirms the importance of eventual competitive flow., (© The Author(s) 2014.)

Background: Improvements in myocardial perfusion and thickening were compared in coronary artery bypass grafting patients who received saphenous vein (SV) Y-composite grafts versus those who received right internal thoracic artery ([R]ITA) Y-composite grafts., Methods: Of the 224 patients enrolled in a randomized clinical trial, 116 patients (SV group, n = 65; RITA group, n = 51) in whom myocardial single-photon-emission computed tomography was performed preoperatively, and at 3 months and 1 year postoperatively, were retrospectively studied. A 20-segment model was adopted, and a total of 792 ischemic myocardial segments (SV group, n = 443; RITA group, n = 349) were analyzed. The reversibility score (rest minus stress perfusion value) as an indicator of ischemic myocardium, and Z-values for segmental myocardial thickening, were calculated., Results: Compared with preoperative values, both myocardial perfusion and segmental myocardial thickening had improved significantly at 3 months and 1 year postoperatively (reversibility scores [mean ± SD] were, respectively: 13.5 ± 8.0 vs 5.8 ± 6.2 and 5.1 ± 6.2, P < .001; Z-values were -1.13 ± 1.53 vs -0.62 ± 1.40 and -0.67 ± 1.35, P < .001). Mixed-effect model analyses showed no differences in improvements in myocardial perfusion and segmental myocardial thickening between the 2 groups 1 year after revascularization. Separate analysis demonstrated less improvement of myocardial perfusion in the right coronary artery territory of the RITA group than the SV group, with marginal significance (P = .056)., Conclusions: Improvements in myocardial perfusion and segmental myocardial thickening were similar between the 2 groups at 1 year after revascularization. The SV, versus the right ITA, composite graft may be more beneficial in perfusion improvement of the right coronary artery territory., (Copyright © 2015 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.)

Background: External stents inhibit saphenous vein graft (SVG) intimal hyperplasia in animal studies. We investigated whether external stenting inhibits SVG diffuse intimal hyperplasia 1 year after coronary artery bypass graft surgery., Methods: Thirty patients with multivessel disease undergoing coronary artery bypass graft surgery were enrolled. In addition to an internal mammary artery graft, each patient received one external stent to a single SVG randomly allocated to either the right or left coronary territories; and one or more nonstented SVG served as the control. Graft patency was confirmed at the end of surgery in all patients. The primary endpoint was SVG intimal hyperplasia (mean area) assessed by intravascular ultrasonography at 1 year. Secondary endpoints were SVG failure, ectasia (>50% initial diameter), and overall uniformity as judged by Fitzgibbon classification., Results: One-year follow-up angiography was completed in 29 patients (96.6%). All internal mammary artery grafts were patent. Overall SVG failure rates did not differ significantly between the two groups (30% stented versus 28.2% nonstented SVG, p = 0.55). The SVG mean intimal hyperplasia area, assessed in 43 SVGs, was significantly reduced in the stented group (4.37 ± 1.40 mm(2)) versus nonstented group (5.12 ± 1.35 mm(2), p = 0.04). In addition, stented SVGs demonstrated marginally significant improvement in lumen uniformity (p = 0.08) and less ectasia (6.7% versus 28.2%, p = 0.05). There was some evidence that ligation of side branches with metallic clips increased SVG failure in the stented group., Conclusions: External stenting has the potential to improve SVG lumen uniformity and reduce diffuse intimal hyperplasia 1 year after coronary artery bypass graft surgery., (Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Objective: The Saphenous Vein Versus Right Internal Thoracic Artery as a Y-Composite Graft (SAVE RITA) trial was designed to evaluate the noninferiority of the saphenous vein (SV) compared with the right internal thoracic artery ([R]ITA) used as a Y-composite graft., Methods: A total of 224 patients who had undergone off-pump revascularization for multivessel coronary artery disease using the SV or RITA as a Y-composite graft based on the in situ left ITA were assigned randomly to the SV Y-composite graft (SV group, n = 112) or free RITA Y-composite graft (RITA group, n = 112). The primary endpoint was the 1-year angiographic patency rate of the second limb conduits (SV or RITA). Postoperative 1-year coronary angiograms were performed in 215 patients (SV group, 108; RITA group, 107)., Results: The overall graft patency rate was 97.4% (745 of 765) at 1 year (97.9% in the SV group vs 96.9% in the RITA group, P = .362). The primary endpoint of the study, the 1-year patency rate of the SV composite grafts, was 97.1% (238 of 245) and was noninferior to that of the RITA composite grafts (97.1% [198 of 204]) with a 95% lower confidence limit of -2.6% (P < .001 for noninferiority). The graft qualities, evaluated using the FitzGibbon patency grades, were also similar between the 2 groups (P = .948). No statistically significant differences were found in the overall survival rates between the 2 groups at 1 and 4 years (P = .998). Also, no statistically significant differences were found between the 2 groups in the freedom from major adverse cardiac and cerebrovascular event rates at 1 and 4 years (P = .597)., Conclusions: The SV composite grafts were noninferior to the RITA composite grafts in terms of the 1-year angiographic patency rates., (Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.)

Even after performed mammary artery bypass surgery, some patients continued to have clinical manifestations of angina pectoris. This may be associated with the development of coronary stealing syndrome due to the fact that the native intrathoracic artery has large lateral branches. Current methods for embolization of arteries of different diameters make it possible to accomplish this task reasonably safely and in full measure. This paper describes a clinical case of reembolization of the lateral branch of a mammary artery shunt with an intravascular coil.

Background: Multiple arterial grafts, in addition to the left internal thoracic artery, improve long-term survival after coronary artery bypass grafting (CABG); yet, the use of this procedure remains low for both the right internal thoracic artery (RITA) and the radial artery (RA). To identify the optimal arterial conduit to deploy for revascularization of diabetic patients, we compared the outcomes for RA and RITA grafts to the circumflex coronary., Methods: From January 1, 1995, to December 31, 2011, 908 consecutive diabetic patients underwent first-time, isolated CABG (99% on-pump), 659 with the RA and 502 with the RITA, respectively, in two affiliated hospitals. Data were prospectively collected, and late mortality was determined from the Social Security Death Index. Propensity matching, based on preoperative and operative variables, identified 202 matched pairs from each group., Results: Long-term survival was similar for matched patients. Mortality, myocardial infarction, reoperation for bleeding, stroke, sepsis, and renal failure were not significantly different between groups. However, deep sternal wound infection (p<0.035) and respiratory failure (p<0.048) favored the RA group, in which the total major adverse events were significantly fewer (p=0.002)., Conclusions: In diabetic patients undergoing multivessel revascularization with either RA or RITA grafts to the circumflex coronary, long-term survival is similar. However, RA patients experienced significantly fewer respiratory or sternal wound adverse events. The RA is the preferred conduit to extend to more diabetic patients the recognized survival benefit of a multiple arterial graft strategy., (Copyright © 2014 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Objective: The main purpose of this study was to assess the patency of left internal thoracic artery (LITA) graft by using color Doppler ultrasonography (CDUSG) and furthermore to determine the sensitivity and specificity of CDUSG for patency by using coronary angiography as the reference standard., Methods: This study is an observational cohort study on diagnostic accuracy that was held between August 2008 and October 2009. CDUSG was performed in 138 consecutive patients who had angina symptom or positive ischemic findings following coronary artery bypass surgery. LITA blood flow velocity at peak-systole (PSV), diastole (PDV) and end-diastole (EDV) was recorded. All patients were also assessed by coronary angiography for LITA graft patency. Statistical analysis was performed by using independent samples t-test, Mann-Whitney U test, chi-square test and receiver operating curve analyses (ROC)., Results: Seventy-eight of all patients had functional LITA grafts and 59 patients had dysfunctional LITA grafts according to CDUSG-derived parameters, whereas we cannot conclude about one patient's LITA graft functionality. The LITA grafts were visualized angiographically in all cases. Of all 138 patients, 60 patients had dysfunctional LITA grafts after angiographic evaluation. The ROC analyses showed that PDV (AUC=0.899, 95% CI 0.844 to 0.953; p<0.001) and EDV (AUC=0.900; 95% CI 0.847 to 0.953; p<0.001) values were also strongly associated with graft functionality. We found out that CDUSG predicts LITA graft functionality with a sensitivity and specificity of 100% and 98.4% respectively. The accuracy of the CDUSG was calculated as 99.3%., Conclusion: CDUSG is a reliable non-invasive method for assessment of LITA graft patency.

Coronary artery disease is recognized as a major health problem worldwide, particularly because of the associated morbidity and mortality. Coronary artery bypass grafting has been an established mainstay in the treatment of this disease for almost half a century and is arguably the most intensively studied surgical procedure ever undertaken. Because of its unique properties, the human internal mammary artery has long been considered the best graft to use in this type of surgery. Previous studies have shown several advantages of this graft compared with others, that is, lower incidence of atherosclerosis. However, few comparative studies on the reactivity of this artery have been published. Moreover, these studies usually focus on isolated cardiovascular risk factors rather than combined risk factors. In fact, patients who require coronary revascularization usually present multiple risk factors, which can interfere with several pathways of regulation of vascular function, namely endothelial function. Several diseases and cardiovascular risk factors have been shown to interfere with endothelial function, promoting the production of vasoconstrictors, inhibiting the production of vasodilators, or both, and thus eventually leading to endothelial dysfunction. Therefore, it is of great interest to study the endothelial function, particularly of the human internal mammary artery, in the presence of combined cardiovascular risk factors and concomitant diseases. Many techniques have been developed to assess the endothelial function, in particular, studies on isolated arteries, as well as spectroscopic, electrochemical, and immunological methods, among others.

Objective: To assess the patency of the pedicled right internal thoracic artery with an anteroaortic course and compare it to the patency of the left internal thoracic artery , in anastomosis to the left anterior descending artery in coronary artery bypass grafting by using coronary CT angiography at 6 months postoperatively., Methods: Between December 2008 and December 2011, 100 patients were selected to undergo a prospective coronary artery bypass grafting procedure without cardiopulmonary bypass. The patients were randomly divided by a computer-generated list into Group-1 (G-1) and Group-2 (G-2), comprising 50 patients each, the technique used was known at the beginning of the surgery. In G-1, coronary artery bypass grafting was performed using the left internal thoracic artery for the left anterior descending and the free right internal thoracic artery for the circumflex, and in G-2, coronary artery bypass grafting was performed using the right internal thoracic artery pedicled to the left anterior descending and the left internal thoracic artery pedicled to the circumflex territory., Results: The groups were similar with regard to the preoperative clinical data. A male predominance of 75.6% and 88% was observed in G-1 and G-2, respectively. Five patients migrated from G-1 to G-2 because of atheromatous disease in the ascending aorta. The average number of distal anastomoses was 3.48 (SD=0.72) in G-1 and 3.20 (SD=0.76) in G-2. Coronary CT angiography in 96 re-evaluated patients showed that all ITAs, right or left, used in situ for the left anterior descending were patent. There were no deaths in either group., Conclusion: Coronary artery bypass grafting surgery involving anastomosis of the anteroaortic right internal thoracic artery to the left anterior descending artery has an outcome similar to that obtained using the left internal thoracic artery for the same coronary site.

Objective: Transit time flow measurement (TTFM) is a method used to assess intraoperative blood flow after vascular anastomoses. Angiography represents the criterion standard for the assessment of graft patency after coronary artery bypass grafting (CABG). The purpose of this study was to compare flow measurements from TTFM to diagnostic angiography., Methods: From October 9, 2009, to April 30, 2012, a total of 259 patients underwent robotic-assisted CABG procedures at a single institution. Of these, 160 patients had both TTFM and either intraoperative or postoperative angiography of the left internal mammary artery to the left anterior descending coronary artery graft. Transit time flow measurements were obtained after completion of the anastomosis and after administration of protamine before chest closure. Transit time flow measurement assessment included pulsatility index, diastolic fraction, and flow (milliliters per minute). Angiograms were graded according to the Fitzgibbon criteria. The patients were grouped according to angiographic findings, with perfect grafts defined as FitzGibbon A and problematic grafts defined as either Fitzgibbon B or O., Results: Overall, there were 152 (95%) of 160 angiographically perfect grafts (FitzGibbon A). Of the eight problematic grafts, five were occluded (Fitzgibbon O) and three had significant flow-limiting lesions (FitzGibbon B). Two patients had intraoperative graft revision after completion angiography, one had redo CABG during the same hospitalization, and five were treated with percutaneous coronary intervention. A significant difference was seen in mean ± SD flow (34.3 ± 16.8 mL/min vs 23.9 ± 12.5 mL/min, P = 0.033) between patent and nonpatent grafts but not in pulsatility index (1.98 ± 0.76 vs 1.65 ± 0.48, P = 0.16) or diastolic fraction (73.5% ± 8.45% vs 70.9% ± 6.15%, P = 0.13)., Conclusions: Although TTFM can be a useful tool for graft assessment after CABG, false negatives can occur. Angiography remains the criterion standard to assess graft patency and quality of the anastomosis after CABG.

Background: Injury incurred while saphenous veins are being obtained results in poor graft patency and impairs the results of coronary artery bypass grafting. A novel method of obtaining veins, the no-touch technique, has shown improved long-term saphenous vein graft patency., Methods: This randomized trial included 108 patients undergoing coronary artery bypass grafting and compared the patency of no-touch saphenous vein with that of radial artery grafts. Each patient was assigned to receive one no-touch saphenous vein and one radial artery graft to either the left or the right coronary territory to complement the left internal thoracic artery., Results: Angiography was performed in 99 patients (92%) at a mean of 36 months postoperatively. Graft and grafted coronary artery patency was evaluated. The patency of grafts for no-touch saphenous vein and radial artery was 94% versus 82% (p = 0.01), respectively. The patency of coronary arteries grafted with no-touch saphenous vein and radial artery grafts was 95% versus 84% (p = 0.005), respectively. Eighty-nine of 96 (93%) left internal thoracic artery grafts were patent., Conclusions: No-touch saphenous vein grafts showed a significantly higher patency rate than the radial artery grafts and the patency was comparable to the patency for left internal thoracic artery grafts. This highlights the improvement in saphenous vein graft quality with the no-touch technique and increases the number of situations in which saphenous veins may be preferable to radial artery grafts as conduits in coronary artery bypass grafting., (Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)