Mammary Artery Research Articles

How to robotically take down a mammary artery.

How to robotically take down a mammary artery.

Robotic-Assisted Minimally Invasive Direct Coronary Artery Bypass Grafting: A Surgical Technique.

In recent years, there has been a growing interest in robotic-assisted coronary artery revascularization in Europe. Two different types of surgery can be performed using a robotic platform: RA-MIDCAB, in which the mammary artery is harvested endoscopically with robotic assistance and off-pump bypass graft is achieved under direct vision through mini thoracotomy, and TE-CAB, completely robotically performed. We started the robotic cardiac surgery program for mitral valve disease in our hospital, Humanitas Gavazzeni (Bergamo, Italy), in 2019; and in 2021, we addressed our experience with RA-MIDCAB. After a learning curve period, we have developed our technique to optimize the benefits offered by the robotic platform, tailoring strategy to individual patients, based on preoperative radiological images.

Single-Cell Gene-Regulatory Networks of Advanced Symptomatic Atherosclerosis.

While our understanding of the single-cell gene expression patterns underlying the transformation of vascular cell types during the progression of atherosclerosis is rapidly improving, the clinical and pathophysiological relevance of these changes remains poorly understood. Single-cell RNA sequencing data generated with SmartSeq2 (≈8000 genes/cell) in 16 588 single cells isolated during atherosclerosis progression in Ldlr-/-Apob100/100 mice with human-like plasma lipoproteins and from humans with asymptomatic and symptomatic carotid plaques was clustered into multiple subtypes. For clinical and pathophysiological context, the advanced-stage and symptomatic subtype clusters were integrated with 135 tissue-specific (atherosclerotic aortic wall, mammary artery, liver, skeletal muscle, and visceral and subcutaneous, fat) gene-regulatory networks (GRNs) inferred from 600 coronary artery disease patients in the STARNET (Stockholm-Tartu Atherosclerosis Reverse Network Engineering Task) study. Advanced stages of atherosclerosis progression and symptomatic carotid plaques were largely characterized by 3 smooth muscle cells (SMCs), and 3 macrophage subtype clusters with extracellular matrix organization/osteogenic (SMC), and M1-type proinflammatory/Trem2-high lipid-associated (macrophage) phenotypes. Integrative analysis of these 6 clusters with STARNET revealed significant enrichments of 3 arterial wall GRNs: GRN33 (macrophage), GRN39 (SMC), and GRN122 (macrophage) with major contributions to coronary artery disease heritability and strong associations with clinical scores of coronary atherosclerosis severity. The presence and pathophysiological relevance of GRN39 were verified in 5 independent RNAseq data sets obtained from the human coronary and aortic artery, and primary SMCs and by targeting its top-key drivers, FRZB and ALCAM in cultured human coronary artery SMCs. By identifying and integrating the most gene-rich single-cell subclusters of atherosclerosis to date with a coronary artery disease framework of GRNs, GRN39 was identified and independently validated as being critical for the transformation of contractile SMCs into an osteogenic phenotype promoting advanced, symptomatic atherosclerosis.

Right Anterior versus Right Transaxillary Access for Minimally Invasive Aortic Valve Replacement: A Propensity Matched Competitive Analysis.

(1) Background: Right anterior thoracotomy (RAT-AVR) has been the sole established sternum-sparing technique for minimally invasive aortic valve replacement (MICS-AVR) thus far. Nevertheless, transaxillary access, known as Minimally Invasive Cardiac LATeral Surgery (MICLATS-AVR), represents the latest and innovative advancement in sternum-sparing MICS-AVR access routes. In this study, procedural and clinical outcomes of a substantial transaxillary MICS-AVR cohort are compared to those of a RAT-AVR control group; (2) Patients and Methods: This retrospective study included 918 consecutive patients who underwent MICS-AVR at our facility between 2014 and 2022. This cohort was divided into two surgical access-related groups: RAT-AVR (n = 492) and MICLATS-AVR (n = 426). Procedural data, operative morbidity, and mortality were compared between groups. Further analysis was performed using propensity score matching; (3) Results: After matching, 359 pairs of patients were included and analyzed. There were no notable differences observed between the two groups regarding major adverse cardio-cerebral events. Despite longer cardiopulmonary bypass time in the MICLATS-AVR group (63.1 ± 20.4 min vs. 66.4 ± 18.2 min; p ≤ 0.001) the skin-to-skin time (129.4 ± 35.9 min. vs. 126.5 ± 29.8 min.; p = 0.790) and the aortic cross-clamp time was comparable between both groups (41.9 ± 13.3 min. vs. 43.5 ± 14.4 min.; p = 0.182). The overall hospital stay was significantly shorter in the MICLATS-AVR cohort (9.7 ± 5.2 days vs. 9.2 ± 4.5 days; p = 0.01). Both groups were comparable in terms of postoperative morbidities. However, significantly lower rates of postoperative impaired wound healing were noted in the MICLATS-AVR group (11.7% vs. 3.9%, p < 0.001); (4) Conclusions: In comparing MICLATS-AVR and RAT-AVR, our study found MICLATS-AVR to be at least as safe and time-efficient as RAT-AVR, with no significant differences in MACCE. MICLATS-AVR showed a shorter hospital stay and lower postoperative wound issues, indicating its feasibility and safety as an alternative. Notably, MICLATS-AVR is sternum- and bone-sparing, preserving the right mammary artery, and facilitates combined procedures like multiple valve surgeries.

Early and Mid-Term Outcomes of Coronary Artery Bypass Grafting in Adults With Congenital Heart Disease

Atherosclerotic coronary artery disease (CAD) is well-studied in acquired cardiac diseases; however, little data exist regarding outcomes of adult congenital heart disease (ACHD) with CAD. This study examined patients who underwent coronary artery bypass grafting (CABG) during repair of ACHD. This was a retrospective study of patients who underwent CABG for CAD concomitant with ACHD repair 1972-2021. Demographic information, ACHD diagnosis, surgical history, operative details, and outcomes were analyzed. Data are presented as median (interquartile range [IQR]). 157 patients were identified with a median age of 63 (IQR 17) years. Left anterior descending (LAD) was the predominant diseased artery (109 patients [69%]); of those 83 (76%) were treated with mammary artery. 90 (57.3%) patients had 1 bypass, 42 (26.7%) 2, 19 (12%) 3, and 6 (3.8%) had 4. There has been no early mortality since 1988. There was no long-term survival difference between the patients with LAD disease treated with mammary compared to vein (P = 0.68), but early mortality was higher in those treated with vein (10.3% vs 0%, P = 0.018). Late recurrent angina was found in 18 patients (12%) and recurrent CAD found in 17 patients (11%), with 16 patients (10%) requiring CAD reintervention. At most recent follow-up (7.2 [IQR 11.4] years), 101 (64.3%) patients were deceased at 10 (IQR 13.1) years after surgery. Surgical revascularization for CAD may be necessary during the treatment of ACHD, most commonly for LAD disease. Early mortality was low in recent decades. Continued surveillance for recurrent CAD is required.

A CLINICAL CASE OF SECONDARY HYPERTENSION IN A 20-YEAR-OLD FEMALE WITH COARCTATION OF THE AORTA

Objective: Coarctation of the aorta (CoA) is a curable cause of secondary hypertension. Patients with CoA and associated heart disease typically are diagnosed in childhood, while isolated CoA may not be recognized until adulthood. Design and method: We report a case of diagnosis and treatment of CoA in a young female, previously observed with a diagnosis of essential hypertension. Results: A 20 years old female, diagnosed with hypertension at the age of 18, with difficult control of blood pressure (BP) values under treatment with angiotensin-converting enzyme inhibitors, beta-blockers and diuretics. The patient was referred to our clinic for evaluation. The clinical examination showed normal body development. BP on the left arm was 203/115 mm Hg, on the right arm - 206/115 mm Hg, normal heart sounds, 76 bpm. A systolic murmur was audible at the parasternal left area. BP on both legs was 140/90 mm Hg. There were no clinically significant abnormalities in other organs and systems. At transthoracic echocardiography we found the signs of a CoA, with a gradient of 80/32 mm Hg, and post-stenotic blood flow in the abdominal aorta. According to the computed tomography angiography signs of CoA in a typical place were confirmed as well as collateral blood flow through the dilated intercostal and mammary arteries. A week after admission to the hospital an operation of resecting the CoA, prosthetics of the arch and descending aorta, and transection of the aortopulmonary ligament was performed. The postoperative period was uneventful, the patient was discharged 10 days after the intervention with the recommendations of continuous administration of metoprolol 100 mg, torasemide 5 mg. At the 3–month follow–up visit the BP was stabilized at 130/80 mm Hg. Conclusions: This clinical case presented a rare isolated type of CoA and demonstrates the importance of qualitative examination of young patients with hypertension, including BP measurement on the lower extremities and transthoracic echocardiography with a compulsory examination of the aorta.

Cerebral Protection at Moderate Hypothermia: Is an Inadequate Circle of Willis Only a Theoretical Concern?

We congratulate Ebuoka and colleagues1 on their management of this challenging patient with an interrupted aortic arch and an aberrant right subclavian artery. Taking advantage of the inherent continuity between the branches of the subclavian artery, the authors reestablished vertebral flow from the proximal arch by turning the right mammary artery up to the ipsilateral carotid and transecting the aberrant subclavian at the descending aorta. For surgeons using moderate hypothermia, reconstruction of the aberrant right subclavian artery in this manner is compelling in that it optimizes cerebral blood flow during arch isolation while also simplifying the reconstruction of the distal aortic arch.

Humanoids for teaching and training coronary artery bypass surgery to the next generation of cardiac surgeons.

OBJECTIVESTechnical skills are an essential component of cardiac surgery, and the operating room is becoming an even more challenging environment for trainees who want to acquire such skills. Simulation, which partially overcomes this limitation, represents a valid adjunct to surgical education. We describe an original simulator and provide results in terms of trainees’ evaluations and ratings.METHODSWe used a humanoid that is a silicone replica of the chest of an adult human that provides a complete anatomical platform for hands-on skin-to-skin practice of surgical techniques in arrested heart coronary artery bypass graft (CABG) surgery cases. Learners were residents in cardiac surgery. The teaching sessions included 2 full three-vessel CABG procedures using both mammary arteries and a hydrogel vein. Five board-certified cardiovascular surgeons scored the surgical activity of all trainees. The trainees were asked to complete an exit questionnaire to evaluate their course.RESULTSOverall, 16 residents participated in the simulation, including 5 women and 11 men, with a mean age of 30 ± 4 years, all of whom had at least 2 years of cardiac surgery training. All participants completed the 2 CABG operations. Three mammary arteries (4.6%) were seriously damaged during harvesting. In 1 case (3.1%), an aortic tear occurred during aortic cannulation. Each trainee performed overall 6 distal and 2 proximal coronary anastomoses. All participants agreed that the ‘humanoid reproduces real-life situations, the feeling is realistic, and they are now more confident in performing coronary anastomosis’.CONCLUSIONSTrainees involved in this simulation curriculum acquired and refined technical skills that could be applied directly to human patients. In addition, we were able to foster a higher level of teamwork within the operating room team.

Graphene Oxide Coating Improves the Mechanical and Biological Properties of Decellularized Umbilical Cord Arteries.

The lack of small-diameter vascular grafts (inner diameter <5 mm) to substitute autologous grafts in arterial bypass surgeries has a massive impact on the prognosis and progression of cardiovascular diseases, the leading cause of death globally. Decellularized arteries from different sources have been proposed as an alternative, but their poor mechanical performance and high collagen exposure, which promotes platelet and bacteria adhesion, limit their successful application. In this study, these limitations were surpassed for decellularized umbilical cord arteries through the coating of their lumen with graphene oxide (GO). Placental and umbilical cord arteries were decellularized and perfused with a suspension of GO (C/O ratio 2:1) with ∼1.5 μm lateral size. A homogeneous GO coating that completely covered the collagen fibers was obtained for both arteries, with improvement of mechanical properties being achieved for umbilical cord decellularized arteries. GO coating increased the maximum force in 27%, the burst pressure in 29%, the strain in 25%, and the compliance in 10%, compared to umbilical cord decellularized arteries. The achieved theoretical burst pressure (1960 mmHg) and compliance (13.9%/100 mmHg) are similar to the human saphenous vein and mammary artery, respectively, which are used nowadays as the gold standard in coronary and peripheral artery bypass surgeries. Furthermore, and very importantly, coatings with GO did not compromise the endothelial cell adhesion but decreased platelet and bacteria adhesion to decellularized arteries, which will impact on the prevention of thrombosis and infection, until full re-endothetialization is achieved. Overall, our results reveal that GO coating has an effective role in the improvement of decellularized umbilical cord artery performance, which is a huge step toward their application as a small-diameter vascular graft.

Does the use of the skeletonized internal thoracic artery result in less postoperative bleeding than the pedicled internal thoracic artery in coronary artery bypass surgery?

Objective: To compare the postoperative bleeding between the skeletonized grafts and pedicled internal thoracic artery (ITA) in coronary artery bypass.&#x0D; Material and Method: 132 elective patients submitted to the surgery of myocardial revascularization were retrospectively analyzed and the sample was equally distributed in groups according to the dissection performed on the ITA: G1, skeletonized and G2, pedicled. In both methods, the dissection was finished before the heparinization and the installation of extracorporeal circulation. The following clinical parameters were evaluated: extracorporeal circulation time, aortic clamping, drainage debit and administration of hemocomponents (erythrocytes and platelets).&#x0D; &#x0D; Results: The average number of platelets concentrations and the drainage debit on the postoperative period were statistically higher for the pedicled dissection of the ITA compared to the skeletonized one. No statistically significant differences were observed regarding the use of one or two mammary arteries, as well as for the time of extracorporeal circulation and anoxia in the studied groups.&#x0D; Conclusion: The skeletonized preparation of the internal thoracic artery significantly reduced the blood loss after an elective surgery of myocardial revascularization.

Current Impact of Cardiopulmonary Bypass in Coronary Artery Bypass Grafting in São Paulo State.

ResumoFundamento Resultados prévios com o uso de circulação extracorpórea (CEC) geram dificuldades na escolha do melhor tratamento para cada paciente na cirurgia de revascularização miocárdica (CRM) no contexto atual.Objetivo Avaliar o impacto da CEC no cenário atual da CRM no estado de São Paulo.Métodos Foram analisados 2.905 pacientes submetidos à CRM de forma consecutiva em 11 centros do estado de São Paulo pertencentes ao Registro Paulista de Cirurgia Cardiovascular (REPLICCAR) I. Dados perioperatórios e de seguimento foram colocados via on-line por especialistas treinados e capacitados em cada hospital. Foram analisadas as associações das variáveis perioperatórias com o tipo de procedimento (com ou sem CEC) e com os desfechos. A mortalidade esperada foi calculada por meio do EuroSCORE II (ESII). Os valores de p menores de 5% foram considerados significativos.Resultados Não houve diferença significativa em relação à idade dos pacientes entre os grupos (p=0,081). Dentre os pacientes, 72,9% eram de sexo masculino; 542 pacientes foram operados sem CEC (18,7%). Das características pré-operatórias, pacientes com infarto agudo do miocárdio (IAM) prévio (p=0,005) e disfunção ventricular (p=0,031) foram operados com CEC; no entanto, pacientes de emergência ou em classe funcional New York Heart Association (NYHA) IV foram operados sem CEC (p<0,001). O valor do ESII foi semelhante para ambos os grupos (p=0,427). Na CRM sem CEC, houve preferência pelo uso do enxerto radial (p<0,001) e com CEC pela artéria mamária direita (p<0,001). No pós-operatório, o uso de CEC esteve associado com reoperação por sangramento (p=0,012).Conclusão Atualmente, no REPLICCAR, reoperação por sangramento foi o único desfecho associado ao uso da CEC na CRM. (Arq Bras Cardiol. 2020; 115(4):595-601)

A novel endothelial damage inhibitor for the treatment of vascular conduits in coronary artery bypass grafting: protocol and rationale for the European, multicentre, prospective, observational DuraGraft registry

BackgroundVein graft disease (VGD) impairs graft patency rates and long-term outcomes after coronary artery bypass grafting (CABG). DuraGraft is a novel endothelial-damage inhibitor developed to efficiently protect the structural and functional integrity of the vascular endothelium. The DuraGraft registry will evaluate the long-term clinical outcomes of DuraGraft in patients undergoing CABG procedures.MethodsThis ongoing multicentre, prospective observational registry will enrol 3000 patients undergoing an isolated CABG procedure or a combined procedure (ie, CABG plus valve surgery or other surgery) with at least one saphenous vein grafts or one free arterial graft (ie, radial artery or mammary artery). If a patient is enrolled, all free grafts (SVG and arterial will be treated with DuraGraft. Data on baseline, clinical, and angiographic characteristics as well as procedural and clinical events will be collected.The primary outcome measure is the occurrence of a major adverse cardiac event (MACE; defined as death, non-fatal myocardial-infarction, or need for repeat-revascularisation). Secondary outcome measures are the occurrence of major adverse cardiac and cerebrovascular events (MACCE; defined as death, non-fatal myocardial-infarction, repeat-revascularisation, or stroke), patient-reported quality of life, and health-economic data. Patient assessments will be performed during hospitalisation, at 1-month, 1-year, and annually thereafter to 5 years post-CABG. Events will be adjudicated by an independent clinical events committee. This European, multi-institutional registry will provide detailed insights into clinical outcome associated with DuraGraft.DiscussionThis European, multi-institutional registry will provide detailed insights into clinical outcome associated with the use of DuraGraft. Beyond that, and given the comprehensive data sets comprising of patient, procedural, and graft parameters that are being collected, the registry will enable for multiple subgroup analyses targeting focus groups or specific clinical questions. These may include analysis of subpopulations such as patients with diabetes or multimorbid high-risk patients (patient level), evaluation of relevance of harvesting technique including endoscopic versus open conduit harvesting (procedural level), or particular graft-specific aspects (conduit level).Trial registrationClinicalTrials.gov NCT02922088. Registered October 3, 2016.Ethics and disseminationThe regional ethics committees have approved the registry. Results will be submitted for publication.

Significant infrarenal aortic stenosis in pregnancy: a case report

BackgroundHypertension is common in pregnant women presenting with aortic coarctation or Takayasu’s arteritis. Uncontrolled hypertension leads to increased adverse maternal and neonatal events.Case presentationA 36-year-old gravida 2, para 1 Caucasian woman presented at 9 weeks of gestation with headaches but normal blood pressure. She had a past medical history of an in vitro fertilization pregnancy complicated by preeclampsia at 27 weeks of gestation (birth weight 1900 g) and infrarenal aortic stenosis. In the current pregnancy, she received aspirin and calcium as preeclampsia prophylaxis, remained normotensive throughout pregnancy, and was delivered by elective cesarean section at 37 weeks without complications.ConclusionsThis case demonstrates a significant chronic aortopathy in pregnancy with normal fetal growth and uterine blood flow through collateral supply from the internal mammary and epigastric arteries.

PHENOMENON OF DEMIKHOV. In the Sklifosovsky Institute (1960–1986). The Institute Scientific Session dedicated to the 150th anniversary of the Sheremetev hospital foundation (November 16–18, 1960)

The article has covered the first 5 months of V.P. Demikhov's working at N.V. Sklifosovsky Research Institute for Emergency Medicine (since June 1960), and described the Institute Scientific Session held in November 1960 and dedicated to the 150th anniversary of the Sheremetev hospital foundation. Among the issues at that session, the topic of coronary artery failure and its treatment was discussed. However, V.P. Demikhov's presentation on his original technique of direct myocardial revascularization by means of forming the anastomosis between the internal mammary and coronary arteries was greeted coolly. The author believes that, probably, at that time, in November 1960, the idea of making such an operation in clinic could occur to Dr. V.I. Kolesov, one of the Session participants from Leningrad, and he embodied the idea in 1964 after he had mastered the V.P. Demikhov's technique in the experiment.

Predictive value of telomere length on outcome following acute myocardial infarction: evidence for contrasting effects of vascular vs. blood oxidative stress

AimsExperimental evidence suggests that telomere length (TL) is shortened by oxidative DNA damage, reflecting biological aging. We explore the value of blood (BTL) and vascular TL (VTL) as biomarkers of systemic/vascular oxidative stress in humans and test the clinical predictive value of BTL in acute myocardial infarction (AMI).Methods and resultsIn a prospective cohort of 290 patients surviving recent AMI, BTL measured on admission was a strong predictor of all-cause [hazard ratio (HR) [95% confidence interval (CI)]: 3.21 [1.46–7.06], P = 0.004] and cardiovascular mortality (HR [95% CI]: 3.96 [1.65–9.53], P = 0.002) 1 year after AMI (for comparisons of short vs. long BTL, as defined by a T/S ratio cut-off of 0.916, calculated using receiver operating characteristic analysis; P adjusted for age and other predictors). To explore the biological meaning of these findings, BTL was quantified in 727 consecutive patients undergoing coronary artery bypass grafting (CABG), and superoxide (O2.-) was measured in peripheral blood mononuclear cells (PBMNC). VTL/vascular O2.- were quantified in saphenous vein (SV) and mammary artery (IMA) segments. Patients were genotyped for functional genetic polymorphisms in P22ph°x (activating NADPH-oxidases) and vascular smooth muscle cells (VSMC) selected by genotype were cultured from vascular tissue. Short BTL was associated with high O2.- in PBMNC (P = 0.04) but not in vessels, whereas VTL was related to O2.- in IMA (ρ = −0.49, P = 0.004) and SV (ρ = −0.52, P = 0.01). Angiotensin II (AngII) incubation of VSMC (30 days), as a means of stimulating NADPH-oxidases, increased O2.- and reduced TL in carriers of the high-responsiveness P22ph°x alleles (P = 0.007).ConclusionBTL predicts cardiovascular outcomes post-AMI, independently of age, whereas VTL is a tissue-specific (rather than a global) biomarker of vascular oxidative stress. The lack of a strong association between BTL and VTL reveals the importance of systemic vs. vascular factors in determining clinical outcomes after AMI.

Non‐adrenergic Vasoconstriction of Human Blood Vessels to the Trace Amine, β‐Phenylethylamine

Trace amines, such as β‐phenylethylamine (PEA), cause vasoconstriction in animal blood vessels not by indirect sympathomimetic actions but via trace amine‐associated receptors (TAARs). Functional studies were therefore performed on human arteries and veins surplus to coronary artery by‐pass graft (CABG) surgery to establish whether they constrict to PEA and if so whether they are adrenoceptor‐mediated. Internal mammary artery or saphenous vein rings were set up in organ baths containing Kreb's bicarbonate solution at 37±0.5°C gassed with O2:CO2 (95:5) under class 2 containment conditions. 1.5 g resting tension was applied and isometric contraction measured using a computerized Power Lab, Chart 5 data acquisition system (ADInstruments). Cumulative concentration‐response curves (CRC) were obtained for β‐phenylethylamine hydrochloride. Contractions were measured by subtracting baseline tension from plateau responses and expressed as a percentage of the contraction to KCl (60mM) added at the end. Responses were compared by Student's paired t‐test, P≤0.05 indicating significance. PEA showed concentration‐related contractions that were significantly greater at the maximum in the artery (1.53±0.31g, n=9) than the vein (0.55±0.18g, n=10). However, when plotted as % of the KCl maximum contraction, the maximum responses were not significantly different (vein 66.7±9.5%; artery 74.7±4.6% at 3×10−3M), indicating the overall greater contractility of this artery. PEA showed slowly developing contractions in both tissues which reached plateau effect after about 20 min. The reference α‐adrenoceptor agonist, phenylephrine, showed a much more rapid contraction, which was not sustained. In the saphenous vein, PEA (62.8±10.7%KCl) and phenylephrine (61.4±9.7%KCl, n=4) displayed the same maximum responses at 3×10−3M and 3×10−4M respectively, but phenylephrine was more potent. The α1‐adrenoceptor antagonist, prazosin (1μM) dissolved in 1 in 10 DMSO, blocked the responses to phenylephrine in the mammary artery but did not affect the contractions to PEA. Similarly, in the saphenous vein, prazosin (1μM) did not block the contractions to PEA. The DMSO vehicle for prazosin had no effect on PEA in mammary artery or saphenous vein. Thus, the indirect sympathomimetic and trace amine, PEA, has been shown to cause substantial vasoconstriction of human saphenous vein and mammary artery, which would explain its vasopressor actions in humans. This response however was not mediated via α1‐adrenoceptors, but was likely due to stimulation of TAARs.

Right mammary artery and saphenous vein non touch a combination for complete off pump revascularization in coronary surgery without touching the aorta

Right mammary artery and saphenous vein non touch a combination for complete off pump revascularization in coronary surgery without touching the aorta

Abstract 13083: Anatomy Characterization Informs Implant Procedure Design for a Novel Extravascular ICD System

Introduction: Extravascular approaches to ICD therapy in some clinical situations require unique implant methods. Current systems require high energy and don’t provide anti-tachycardia pacing. A new extravascular approach involves placement of a defibrillation lead between the heart and sternum. Due to the unfamiliarity most ICD implanters have with this space, quantification of the anatomy there is crucial for development of a safe and effective procedure. Methods: CT scans were segmented and analyzed to characterize relative locations of structures in or near the substernal space including heart, lungs, sternum, and mammary arteries. Segmentation resulted in faceted 3D surface models. A lead was virtually implanted behind the sternum in the intended location. Proximity distributions from the lead to various structures in the space were characterized at multiple levels of the sternum (up to the 3 rd intercostal space (ICS)). Additionally, the location along the right ventricular (RV) long axis where the lead was closest to the heart was measured. Results: Analysis was completed in 68 patients. The myocardium was closest on average to the virtual lead at the level of the xiphisternal junction (Fig. 1)(5 th - 95 th percentile: 1.0 - 9.9 mm) and furthest away at the 3 rd ICS (4.2 - 47.5 mm). It was closest to lung tissue at the 3 rd ICS (1.2 -14.7 mm) and furthest away at the tip of the xiphoid process (20.7 - 73.9 mm). The mammary arteries were found to be no closer than 11.5 mm to either margin of the sternum at any level. At the xiphisternal junction, the lead sat at ~60% along the RV long axis (0%=RV apex, 100%=tricuspid valve), suggesting close proximity to the central portion of the RV. Conclusions: Meaningful variation exists in the geometric relationships between many of the anatomical structures of the substernal space. Despite this variation, these results support that a lead can be placed in the substernal space close to myocardium while avoiding other organs.

Monoamine oxidase inhibition improves vascular function in mammary arteries from nondiabetic and diabetic patients with coronary heart disease.

Monoamine oxidases (MAOs) are mitochondrial enzymes with 2 isoforms that have emerged as important contributors to cardiovascular oxidative stress via the constant generation of hydrogen peroxide. The present study was purported to assess whether MAO-derived H2O2 contributes to the endothelial dysfunction in mammary arteries harvested from coronary heart disease patients with and without diabetes mellitus subjected to coronary artery bypass grafting. To this aim, the effects of MAO inhibition on vascular contractility to phenylephrine and endothelial-dependent relaxation (EDR) in response to acetylcholine were studied in vascular segments. Clorgyline (irreversible MAO-A inhibitor), selegiline (irreversible MAO-B inhibitor), and moclobemide (reversible MAO-A inhibitor) were applied in the organ bath (10 μmol/L). MAO expression was assessed by immunohistochemistry. We found a constant impairment of EDR that has been significantly attenuated in the presence of the MAO-A and MAO-B inhibitors in both groups of coronary heart disease patients. MAO-B was the dominant isoform in all human diseased vessels. In conclusion, in vitro inhibition of MAO significantly improved EDR in human mammary arteries, regardless of the presence of diabetes. These data suggest that MAO inhibitors might be useful in restoring endothelial response in clinical conditions associated with increased oxidative stress, such as coronary artery disease and diabetes.

Alternativas para lograr la revascularización arterial total usando una o ambas arterias mamarias y el remanente distal de una de ellas como únicos injertos

IntroductionThe aim of all coronary artery bypass grafts should be to allow patients to stay as long as possible without the need to repeat revascularization. Total arterial revascularization contributes to achieving these purposes. ObjectiveTo demonstrate that both mammary arteries can be used in various configurations to achieve total arterial revascularization. Methods35 patients were included, 29 male and 6 female, with age average of 54.2 years, who were revascularized with one or both mammary arteries in the period between January 2012 and September 2014, with a mean follow-up time of 13.1 months. The additive EuroSCORE was 0 for men and 1 for women. ResultsSeven configurations are described to achieve total arterial revascularization using one or both mammary arteries and the distal remnant of a mammary arteries as single grafts. There were no deaths or major complications in patients revascularized. Six months later, all were asymptomatic with no new signs of ischemia in revascularized territories. ConclusionsTotal arterial revascularization using one or both mammary arteries and distal remaining one is possible and gives good results in selected patients.