Design and Evaluation of Augmented Reality-Enhanced Robotic System for Epidural Interventions.

The epidural injection is a medical intervention to inject therapeutics directly into the vicinity of the spinal cord for pain management. Because of its proximity to the spinal cord, imprecise insertion of the needle may result in irreversible damage to the nerves or spinal cord. This study explores enhancing procedural accuracy by integrating a telerobotic system and augmented reality (AR) assistance.

A universal calibration framework for mixed-reality assisted surgery.

Background: Mixed-reality-assisted surgery has become increasingly prominent, offering real-time 3D visualization of target anatomy such as tumors. These systems facilitate translating preoperative 3D surgical plans to the patient's body intraoperatively and allow for interactive modifications based on the patient's real-time conditions. However, achieving sub-millimetre accuracy in mixed-reality (MR) visualization and interaction is crucial to mitigate device-related risks and enhance surgical precision.

Evaluating the Reparative Potential of Secretome from Patient-Derived Induced Pluripotent Stem Cells during Ischemia-Reperfusion Injury in Human Cardiomyocytes.

During a heart attack, ischemia causes losses of billions of cells; this is especially concerning given the minimal regenerative capability of cardiomyocytes (CMs). Heart remuscularization utilizing stem cells has improved cardiac outcomes despite little cell engraftment, thereby shifting focus to cell-free therapies. Consequently, we chose induced pluripotent stem cells (iPSCs) given their pluripotent nature, efficacy in previous studies, and easy obtainability from minimally invasive techniques.

Spontaneous coronary artery dissection: a difficult journey from emergency coronary artery bypass grafting to left ventricular assist device.

Background: Excluding spontaneous coronary artery dissection (SCAD) as an aetiology of acute coronary syndrome in young adults is imperative.

Case Summary: A previously healthy 39-year-old woman experienced sudden severe chest pain, ST-segment elevation on electrocardiogram, necessitating high-dose aspirin and urgent transfer to a revascularization centre. Suffering ventricular tachycardia (VT) and ventricular fibrillation (VF), she underwent two rounds of advanced life support and venoarterial extracorporeal membrane oxygenation.

Significance of the Wnt signaling pathway in coronary artery atherosclerosis.

Introduction: The progression of coronary atherosclerosis is an active and regulated process. The Wnt signaling pathway is thought to play an active role in the pathogenesis of several cardiovascular diseases; however, a better understanding of this system in atherosclerosis is yet to be unraveled.

Methods: In this study, real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blotting were used to quantify the expression of Wnt3a, Wnt5a, and Wnt5b in the human coronary plaque, and immunohistochemistry was used to identify sites of local expression.

Recurrent giant cell myocarditis following orthotopic heart transplant resulting in urgent redo orthotopic heart transplantation: a case report.

Background: Giant cell myocarditis (GCM) is a severe and rapidly progressing condition that can lead to end-stage heart failure. We present a case of a 51-year-old male with a history of orthotopic heart transplantation (OHTx) for GCM, who experienced recurrent GCM in the allograft, leading to progressive heart failure and the need for a second heart transplant.

Case Summary: A 51-year-old male with a history of OHTx for GCM presented with rapidly worsening heart failure symptoms.

Measuring Single-Cell Calcium Dynamics Using a Myofilament-Localized Optical Biosensor in hiPSC-CMs Derived from DCM Patients.

Synchronized contractions of cardiomyocytes within the heart are tightly coupled to electrical stimulation known as excitation-contraction coupling. Calcium plays a key role in this process and dysregulated calcium handling can significantly impair cardiac function and lead to the development of cardiomyopathies and heart failure. Here, we describe a method and analytical technique to study myofilament-localized calcium signaling using the intensity-based fluorescent biosensor, RGECO-TnT.

Hyperelastic Modeling and Validation of Hybrid-Actuated Soft Robot with Pressure-Stiffening.

Soft robots have gained popularity, especially in intraluminal applications, because their soft bodies make them safer for surgical interventions than flexures with rigid backbones. This study investigates a pressure-regulating stiffness tendon-driven soft robot and provides a continuum mechanics model for it towards using that in adaptive stiffness applications. To this end, first, a central single-chamber pneumatic and tri-tendon-driven soft robot was designed and fabricated.

Patient-specific finite element analysis of heart failure and the impact of surgical intervention in pulmonary hypertension secondary to mitral valve disease.

Pulmonary hypertension (PH), a chronic and complex medical condition affecting 1% of the global population, requires clinical evaluation of right ventricular maladaptation patterns under various conditions. A particular challenge for clinicians is a proper quantitative assessment of the right ventricle (RV) owing to its intimate coupling to the left ventricle (LV). We, thus, proposed a patient-specific computational approach to simulate PH caused by left heart disease and its main adverse functional and structural effects on the whole heart.

Extracellular Vesicles as a Cell-free Therapy for Cardiac Repair: a Systematic Review and Meta-analysis of Randomized Controlled Preclinical Trials in Animal Myocardial Infarction Models.

Stem  cell therapy for cardiac regeneration has been gaining traction as a possible intervention for the reduction of the burden associated with MI and heart failure. However, stem cell therapies have several shortcomings, including poor engraftment, limited improvements in cardiac function, and possible teratogenicity. Recently, extracellular vesicles (EVs) from stem cell sources have been explored as a novel therapy to regenerate the injured myocardium in several animal MI trials.

Amniotic stromal stem cell-loaded hydrogel repairs cardiac tissue in infarcted rat hearts via paracrine mediators.

The use of stem cells to repair the heart after a myocardial infarction (MI) remains promising, yet clinical trials over the past 20 years suggest that cells fail to integrate into the native tissue, resulting in limited improvements in cardiac function. Here, we demonstrate the cardioprotective potential of a composite inserting human amniotic stromal mesenchymal stem cells (ASMCs) in a chitosan and hyaluronic acid (C/HA) based hydrogel in a rat MI model. Mechanical characterization of the C/HA platform indicated a swift elastic conversion at 40°C and a rapid sol-gel transition time at 37°C.

Treatment of device thrombus in the HeartWare HVAD: surgical exchange through thoracotomy.

Pump thrombosis can occur in patients with a left ventricular assist device (LVAD). It can be treated medically with thrombolytic agents or surgically. We present a case of a man who successfully underwent an LVAD swap via left anterior thoracotomy due to recurrent thromboses in the inflow cannula.

Bioactive Scaffolds in Stem Cell-Based Therapies for Myocardial Infarction: a Systematic Review and Meta-Analysis of Preclinical Trials.

The use of bioactive scaffolds in conjunction with stem cell therapies for cardiac repair after a myocardial infarction shows significant promise for clinical translation. We performed a systematic review and meta-analysis of preclinical trials that investigated the use of bioactive scaffolds to support stem cell-aided cardiac regeneration, in comparison to stem cell treatment alone. Cochrane Library, Medline, Embase, PubMed, Scopus, Web of Science, and grey literature were searched through April 23, 2020 and 60 articles were included in the final analysis.

The Essential Frailty Toolset in Older Adults Undergoing Coronary Artery Bypass Surgery.

Background The Essential Frailty Toolset (EFT) was shown to be easy to use and predictive of adverse events in patients undergoing aortic valve replacement procedures. The objective of this study was to evaluate the EFT in patients undergoing coronary artery bypass grafting procedures. Methods and Results The McGill Frailty Registry prospectively included patients ≥60 years of age undergoing urgent or elective isolated coronary artery bypass grafting between 2011 and 2018 at 2 hospitals.

Postoperative Nosocomial COVID-19 Infection in Cardiac Surgery: An Uncommon Event With High Mortality Rate.

Background: The COVID-19 pandemic has had a major impact on cardiac surgery patients. Significant reductions in access to surgical treatment have forced surgeons to prioritise patients and follow strict COVID-19 protocols to protect surgeons, staff, and patients. Adult cardiac surgery and the COVID-19 pandemic: aggressive infection mitigation strategies are necessary in the operating room and surgical recovery.

The Role of Wnt/β-Catenin Pathway Mediators in Aortic Valve Stenosis.

Aortic valve stenosis (AVS) is a prevailing and life-threatening cardiovascular disease in adults over 75 years of age. However, the molecular mechanisms governing the pathogenesis of AVS are yet to be fully unraveled. With accumulating evidence that Wnt signaling plays a key role in the development of AVS, the involvement of Wnt molecules has become an integral study target in AVS pathogenesis.

The cytoprotective impact of yes-associated protein 1 after ischemia-reperfusion injury in AC16 human cardiomyocytes.

Unlabelled: The Hippo-signaling pathway is a mechanism implicated in cardiomyocyte cytoprotection and regeneration after a myocardial infarction. Yes-associated protein 1, the main effector protein of this pathway, acts as a co-transcriptional activator to promote cardiomyocyte proliferation and survival. However, the biological mechanisms by which yes-associated protein 1 protects the heart post-MI are currently unknown.

Bioactive scaffolds in stem-cell-based therapies for cardiac repair: protocol for a meta-analysis of randomized controlled preclinical trials in animal myocardial infarction models.

Background: Acute myocardial infarction (MI) remains one of the leading causes of death worldwide with no curative therapy available. Stem cell therapies have been gaining interest as a means to repair the cardiac tissue after MI and prevent the onset of heart failure. Many in vivo reports suggest that the use of stem cells is promising, yet clinical trials suggest that the cells fail to integrate into the native tissue, resulting in limited improvements in cardiac function and repair.

Muscle Mass and Mortality After Cardiac Transplantation.

Background: Frailty assessment is recommended to evaluate the candidacy of adults referred for orthotopic heart transplantation (OHT). Psoas muscle area (PMA) is an easily measured biomarker for frailty. There has yet to be a study examining the prognostic impact of PMA in OHT patients.

Pathological significance of lipoprotein(a) in aortic valve stenosis.

Background And Aims: Aortic valve stenosis (AVS) affects a significant percentage of our elderly population and younger subjects with familial hypercholesterolemia. Lipoprotein(a) [Lp(a)] has been associated with AVS in recent genetic studies. The purpose of this study was to determine the effects of Lp(a) on human aortic valve interstitial cells (HAVICs), and to identify apolipoproteins and phospholipids in diseased human aortic valves.

Pregnancy after heart transplantation: a well-thought-out decision? The Quebec provincial experience - a multi-centre cohort study.

Despite reports of successful pregnancies in heart transplant (HTx) recipients, many centers recommend their patients against maternity. We reviewed our provincial experience of pregnancy in HTx recipients by performing charts review of all known gestations following HTx in the province of Quebec (Canada), stratified between planned and unplanned pregnancies. Long-term survival was compared to HTx recipient women of childbearing age who did not become pregnant.

A Tumor Necrosis Factor-α and Hypoxia-Induced Secretome Therapy for Myocardial Repair.

Background: Poor viability and retention of transplanted bone marrow mesenchymal stem cells (BM-MSC) remains an obstacle in promoting healing after myocardial infarction (MI). This study aimed to understand the migratory, angiogenic, and cardioprotective effects induced by tumor necrosis factor (TNF)-α and hypoxia through rat BM-MSC (rBM-MSC) paracrine secretions, collectively referred to as secretome, after MI.

Methods: Secretome from rBM-MSC cultures treated with various combinations of H9c2 cardiomyoblast-conditioned medium, TNF-α, and hypoxia was initially collected.

Expression of the Frizzled receptors and their co-receptors in calcified human aortic valves.

The cellular mechanisms that induce calcific aortic stenosis are yet to be unraveled. Wnt signaling is increasingly being considered as a major player in the disease process. However, the presence of Wnt Frizzled (Fzd) receptors and co-receptors LRP5 and 6 in normal and diseased human aortic valves remains to be elucidated.