Michael Patrick Vallely

Monash Health · Cardiothoracic Surgery Research Unit

Background It is unknown if the presence of saphenous vein grafting (SVG) adversely affects late survival following coronary surgery with multiple arterial grafting (MAG) versus single arterial grafting. Methods and Results A retrospective, observational, multicenter cohort study from 2001 to 2020 was conducted using the Australian and New Zealand...

For over forty years, coronary artery bypass grafting (CABG) has been recommended to patients with triple vessel disease (TVD) with the aim of providing a survival benefit compared to medical therapy. Generally, the survival benefit of CABG is determined by (a) the volume of myocardium at risk of infarction according to the extent of coronary arter...

As the population ages and co-morbidities become more prevalent, the complexity of patients presenting for coronary artery bypass surgery is increasing. Cardiopulmonary bypass and aortic cross-clamping in these patients carry increased risk and, indeed, in some patients, with ascending aortic disease, the risks are prohibitive. Total-arterial anaor...

Background: There is ongoing debate regarding the optimal strategy and timing for the surgical management of patients with severe concomitant carotid and coronary artery disease. Anaortic off-pump coronary artery bypass (anOPCAB), which avoids aortic manipulation and cardiopulmonary bypass, has been shown to reduce the risk of perioperative stroke...

Introduction: Clear and effective communication is vital in discussions regarding coronary revascularization. Language barriers may limit communication in healthcare settings. Previous studies on the influence of language barriers on the outcomes of patients receiving coronary revascularization have produced conflicting results. The aim of this sy...

Background Minimally invasive direct coronary artery bypass has enabled coronary artery bypass graft to compete with the appeal of less invasive percutaneous coronary procedures. Favorable results of coronary artery bypass surgery performed without the use of cardiopulmonary bypass and without touching the aorta (anOPCAB) have enabled the developme...

Approximately 95% of patients of any age undergoing contemporary, coronary bypass surgery will receive at least 1 saphenous vein graft (SVG). It is recognized that SVG will develop progressive and accelerated atherosclerosis, resulting in a stenosis, and in occlusion that occurs in 50% by 10 years postoperatively. For arterial conduits, there is li...

Randomized trials of stenting versus surgery for patients with unprotected left main (LM) coronary stenosis have largely shown similar survival between the two interventions. However, patients with LM stenosis represent a heterogeneous group in which subgroups likely to benefit from one therapy more than another are difficult to identify. Increasin...

Background Combined on‐pump coronary artery bypass (ONCAB) and surgical aortic valve replacement (SAVR) is the treatment of choice for concomitant severe aortic stenosis and coronary artery disease not amenable to percutaneous coronary intervention. Extensive aortic calcification and atheromatous disease may prohibit cardiopulmonary bypass and aort...

During bypass surgery for peripheral arterial occlusive disease and ischaemic heart disease, autologous graft conduit including great saphenous veins and radial arteries are frequently stored in solution. Endothelial damage adversely affects the performance and patency of autologous bypass grafts, and intraoperative graft storage solutions have bee...

Background Combined ONCAB and SAVR is the treatment of choice for concomitant severe aortic stenosis and coronary artery disease not amenable to PCI intervention. Extensive aortic calcification and atheromatous disease may prohibit cardiopulmonary bypass and aortic cross clamping. In these cases Anaortic OPCAB is a Class I (EACTS 2018) and Class II...

Transit time flow measurement (TTFM) allows quality control in coronary artery bypass grafting but remains largely underused, probably because of limited information and the lack of standardization. We performed a systematic review of the evidence on TTFM and other methods for quality control in coronary artery bypass grafting following PRISMA stan...

Background: Although transcatheter aortic valve implantation (TAVI) has become the standard treatment for severe aortic stenosis in high-risk patients in Australia, there is still limited data on long term survival. Methods: All patients undergoing TAVI at a single tertiary institution between September 2009 and December 2015 were included. The...

Traditional on-pump coronary artery bypass grafting on an arrested heart using a single arterial graft carries 2 main potential drawbacks: the risk of perioperative neurological injury and the known failure rate of vein grafts. To address this, we describe a surgical technique of anaortic, off-pump coronary artery bypass that avoids all manipulatio...

All human cells are coated by a surface layer of proteoglycans, glycosaminoglycans (GAGs) and plasma proteins, called the glycocalyx. The glycocalyx transmits shear stress to the cytoskeleton of endothelial cells, maintains a selective permeability barrier, and modulates adhesion of blood leukocytes and platelets. Major components of the glycocalyx...

Background: Minimally invasive aortic valve replacement (MiAVR) and transcatheter aortic valve implantation (TAVI) provide aortic valve replacement (AVR) by less invasive methods than conventional surgical AVR, by avoiding complete sternotomy. This study directly compares and analyses the available evidence for early outcomes between these two AVR...

Surgical coronary revascularization remains the preferred strategy in a significant portion of patients with coronary artery disease due to superior long‐term outcomes. However, there is a significant risk of perioperative neurologic injury that has influenced guideline recommendations. These complications occur in 1%–5% of patients, ranging from o...

Coronary surgery performed on an arrested heart, using one internal mammary artery and a saphenous vein, carries two main potential drawbacks: the known failure rate of vein grafts and the relatively high rate of neurologic injury. To address these concerns, we describe a technique that achieves complete revascularization without manipulating the a...

Rationale: Transbronchial lung cryobiopsy (TBLC) is an emerging technique for interstitial lung disease (ILD) diagnosis. Good histopathologic agreement between TBLC and surgical lung biopsy (SLB) was demonstrated in the COLDICE Study, however diagnostic confidence was frequently lower for TBLC than SLB. This secondary analysis aimed to characteriz...

Coronary artery and cerebrovascular disease represent a major cause of cardiovascular morbidity and mortality worldwide. Despite technological advancements in percutaneous interventions, surgical revascularization remains the preferred strategy in patients with left main or multivessel disease and in those with complex lesions with high SYNTAX scor...

Background Limb ischemia is a major complication associated with peripheral veno‐arterial extracorporeal membrane oxygenation (VA ECMO). The high velocity jet from arterial cannulae can cause “sandblasting” injuries to the arterial endothelium, with the potential risk of distal embolization and end organ damage. Aim The aim of this study was to id...

Background New-onset atrial fibrillation (NOAF) is a well-recognised, although variably reported complication following surgical aortic valve replacement (SAVR). Rates of NOAF following transcatheter aortic valve implantation (TAVI) seem to be notably less than SAVR, even though this population is typically older and of higher risk. The aim of this...

Diffusion MRI (dMRI) is sensitive to anisotropic diffusion within bundles of nerve axons and can be used to make objective measurements of brain networks. Many brain disorders are now recognised as being caused by network dysfunction or are secondarily associated with changes in networks. There is therefore great potential in using dMRI measures th...

Background: Transbronchial lung cryobiopsy (TBLC) is a novel technique for sampling lung tissue for interstitial lung disease diagnosis. The aim of this study was to establish the diagnostic accuracy of TBLC compared with surgical lung biopsy (SLB), in the context of increasing use of TBLC in clinical practice as a less invasive biopsy technique....

Introduction: Transbronchial lung cryobiopsy (TBLC) is a novel, minimally invasive technique for obtaining lung tissue for histopathological assessment in interstitial lung disease (ILD). Despite its increasing popularity, the diagnostic accuracy of TBLC is not yet known. The COLDICE Study (Cryobiopsy versus Open Lung biopsy in the Diagnosis of In...

Objectives: There are a number of minimally invasive approaches to revascularization of coronary artery disease that involve the left main or proximal left anterior descending artery; however, studies to date provide mixed results. Methods: A Bayesian network meta-analysis was performed to compare early and late postoperative outcomes between pe...

Background Silent brain infarcts ( SBI ) are increasingly being recognized as an important complication of cardiac procedures as well as a potential surrogate marker for studies on brain injury. The extent of subclinical brain injury is poorly defined. Methods and Results We conducted a systematic review and meta‐analysis utilizing studies of SBI...

In recent years, extracorporeal membrane oxygenation has become increasingly common in the treatment of in-hospital cardiac arrest in non-cardiac surgery patients. This includes cardiac arrest secondary to perioperative anaphylactic shock refractory to standard advanced life support protocols, which is a rare but catastrophic event associated with...

Purpose: There are no studies comparing 30-day stroke risk following anaortic off-pump coronary artery bypass grafting (anOPCABG) vs percutaneous coronary intervention (PCI). A network meta-analysis was performed to indirectly compare 30-day stroke risk following anOPCABG vs PCI. Methodology: A comprehensive search from six electronic databases wa...

Purpose: Long-term mortality following off-pump vs onpump coronary artery bypass grafting (CABG) remains controversial, despite recent randomised controlled trials. A systematic review and meta-analysis were performed to assess mortality risk at 5-year follow-up. Methodology: A comprehensive search from six electronic databases was performed from...

We summarize the evidence on the new strategies for coronary artery bypass grafting (CABG). Hybrid CABG implies surgical grafting of the left anterior descending artery and percutaneous treatment of the other target vessels, with the promise of combining the durable benefits of surgery with the less invasive approach of percutaneous coronary interv...

Abstract Relative benefits of coronary artery bypass (CABG) using single and multiple arterial grafting (SAG, MAG) and drug eluting stent (DES) in multivessel coronary disease remain uncertain. We compared SAG, MAG, and DES in a pairwise and network meta-analysis. Randomized trials and adjusted observational studies comparing CABG versus DES were i...

The random-effects model demonstrated no difference in 5-year mortality between OPCAB and CABG (13.9% vs 12.2%; OR 1.19; 95% CI 0.89–1.58; I2 = 56%). Aggregated hazard ratios demonstrated no difference in 5-year mortality between OPCAB and CABG (HR 1.06; 95% CI: 0.94–1.20; I2 = 0%). Therefore, it may be premature to make conclusions on long-term mo...

Coronary surgery performed on an arrested heart, using one internal mammary artery and a saphenous vein carries two main potential drawbacks: the known failure rate of vein grafts and the relatively high rate of neurologic injury. To address these concerns, we describe a technique that achieves complete revascularization without manipulating the as...

Cardiac surgery has been evolving to include minimally invasive, hybrid and transcatheter techniques. Increasing patient age and medical complexity means that critical care management needs to adapt and evolve. Recent advances have occurred in several areas, including ventilation, haemodynamics and mechanical circulatory support, bleeding and coagu...

Background Bilateral internal mammary artery (BIMA) grafts have demonstrated superior long-term outcomes compared with single internal mammary artery (SIMA) grafts. Despite this, BIMA remains widely underutilised due to perceived technical challenges and concerns regarding wound healing. We sought to examine the morbidity and mortality associated w...

Background: Chronic descending thoracic aortic dissection (CDTAD) following surgical repair of ascending aortic dissection requires long-term imaging surveillance. We investigated four-dimensional (4D)-flow magnetic resonance imaging (MRI) with a novel multi-velocity encoding (multi-VENC) technique as an emerging clinical method enabling the dynam...

Cognitive dysfunction is a poorly understood but potentially devastating complication of cardiac surgery. Clinically meaningful assessment of cognitive changes after surgery is problematic because of the absence of a means to obtain reproducible, objective, and quantitative measures of the neural disturbances that cause altered brain function. By u...

Background: Coronary artery bypass grafting (CABG) remains the standard of treatment for 3-vessel and left main coronary disease, but is associated with an increased risk of post-operative stroke compared to percutaneous coronary intervention. It has been suggested that CABG techniques that eliminate cardiopulmonary bypass and reduce aortic manipul...

Online Appendix to Coronary Artery Bypass Grafting With and Without Manipulation of the Ascending Aorta: A Network Meta-Analysis. J Am Coll Cardiol 69:924–936.

Neurocognitive and psychiatric complications are common following cardiac surgery and impact on patient quality of life, recovery from surgery, participation in rehabilitation and long-term mortality. Postoperative cognitive decline, depressive disorders, post-traumatic stress disorder and neurocognitive impairment related to silent brain infarcts...

Herein we detail the cases of three patients transferred on veno-arterial extracorporeal membrane oxygenation (VA ECMO) from a tertiary referral hospital to an ECMO centre. We highlight the benefits of such a transfer and offer this as a model of care for unwell patients likely to require a prolonged period of ECMO support. © 2017, Australian Socie...

Background: Increasingly elderly and high-risk patients are requiring surgical revascularisation for coronary artery disease. Coronary artery bypass grafting (CABG) remains the standard of treatment for three-vessel and left main disease but is associated with an increased risk of stroke compared to percutaneous coronary intervention. Aortic no-tou...