Is there an immunogenomic difference between thoracic and abdominal aortic aneurysms?

BACKGROUND AND AIM: Aortic aneurysms most commonly occur in the infra-renal and proximal thoracic regions. While generally asymptomatic, progressive aneurysmal dilation can become rapidly lethal when dissection or ruptures occurs, highlighting the need for more robust screening. Abdominal aortic aneurysm (AAA) is more prevalent compared to thoracic aortic aneurysm (TAA). The true incidence of TAA is underreported due to the absence of population screening and the silent nature of TAA. To achieve the optimum survival rate in aortic aneurysms, knowledge of natural course, genetic association, and surgical results are needed to be applied with adequate medical treatment and careful selection of patients for operation. The purpose of this paper is to provide a comprehensive review of the literature on natural history, immunology, and genetic differences between thoracic and AAAs. METHOD: The literature was collected from OVID, SCOPUS, and PubMed. RESULTS: (1) AAA expands faster than TAA. AAA expands at approximately 0.3-0.45 cm annually, depending on various factors (advancing age, diameter of aorta, smoking etc.). TAA expands up to 0.3 cm annually in a non-bicuspid aortic valve patient. (2) An increase in Matrix metallopeptidase 1, 2, 9, 12, 14 led to degrading extracellular matrix of the aortic vessel wall. This significantly contributed to the pathogenesis in AAA, whereas overactive Transforming growth factor-beta played a major role in the pathogenesis of TAA. CONCLUSION: In the future, genetic testing may be the gold standard for tackling the geneticheterogeneity of aneurysms, therefore, identifying at-risk individuals developing TAA andAAA earlier.

Tear Size and Location Influence the Pressure of False Lumen Following Type A Aortic Dissection: Perspective of Current Evidence.

Aortic dissection is a surgical emergency which poses a challenge to numerous clinicians across different specialties due to its high rate of associated morbidity and mortalities. Acute type A aortic dissection, which involves the ascending aorta and beyond, is a lethal condition. It is therefore vital to understand the pathophysiology that underlies this condition and the tools that aid its early detection. Haemodynamics factors including lumen wall shear stress and pressure, geometrical factors as entry tear location and size, and the composition of the aortic wall are well known to affect the disease progression. The studies on these factors are well established in Type B aortic dissection but not clearly emphasised in the setting of acute type A aortic dissection. The aim of this paper is to provide a comprehensive review of available literature on the relationship between tear size, location and the pressure of false lumen in acute type A aortic dissection.

The bicuspid aortic valve: Is it an immunological disease process?

Bicuspid aortic valves (BAVs) are the most common congenital cardiac condition and are characterized by a structural abnormality whereby the aortic valve is composed of two leaflets instead of being trileaflet. It is linked to an increased risk for a variety of complications of the aorta, many with an immunological pathogenesis. The aim of this study is to review and analyze the literature regarding immunological processes involving BAVs, associated common pathologies, and their incidence in the population. This study will also examine current trends in surgical and therapeutic approaches to treatment and discuss the future direction of BAV treatment.

Innominate vs. axillary artery cannulation in aortic surgery: a systematic review and meta-analysis

Abstract Objective: To investigate whether axillary artery cannulation has supremacy over innominate artery cannulation in thoracic aortic surgery. Methods: A comprehensive search was undertaken among the four major databases (PubMed, Excerpta Medica dataBASE [EMBASE], Scopus, and Ovid) to identify all randomized and nonrandomized controlled trials comparing axillary to innominate artery cannulation in thoracic aortic surgery. Databases were evaluated and assessed up to March 2017. Results: Only three studies fulfilled the criteria for this meta-analysis, including 534 patients. Cardiopulmonary bypass time was significantly shorter in the innominate group (P=0.004). However, the innominate group had significantly higher risk of prolonged intubation > 48 hours (P=0.04) than the axillary group. Further analysis revealed no significant difference between the innominate and axillary groups for deep hypothermic circulatory arrest time (P=0.06). The relative risks for temporary and permanent neurological deficits as well as in-hospital mortality were not significantly different for both groups (P=0.90, P=0.49, and P=0.55, respectively). Length of hospital stay was similar for both groups. Conclusion: There is no superiority of axillary over innominate artery cannulation in thoracic aortic surgery in terms of perioperative outcomes; however, as the studies were limited, larger scale comparative studies are required to provide a solid evidence base for choosing optimal arterial cannulation site.

Innominate vs. Axillary Artery Cannulation in Aortic Surgery: a Systematic Review and Meta-Analysis.

OBJECTIVE: To investigate whether axillary artery cannulation has supremacy over innominate artery cannulation in thoracic aortic surgery. METHODS: A comprehensive search was undertaken among the four major databases (PubMed, Excerpta Medica dataBASE [EMBASE], Scopus, and Ovid) to identify all randomized and nonrandomized controlled trials comparing axillary to innominate artery cannulation in thoracic aortic surgery. Databases were evaluated and assessed up to March 2017. RESULTS: Only three studies fulfilled the criteria for this meta-analysis, including 534 patients. Cardiopulmonary bypass time was significantly shorter in the innominate group (P=0.004). However, the innominate group had significantly higher risk of prolonged intubation > 48 hours (P=0.04) than the axillary group. Further analysis revealed no significant difference between the innominate and axillary groups for deep hypothermic circulatory arrest time (P=0.06). The relative risks for temporary and permanent neurological deficits as well as in-hospital mortality were not significantly different for both groups (P=0.90, P=0.49, and P=0.55, respectively). Length of hospital stay was similar for both groups. CONCLUSION: There is no superiority of axillary over innominate artery cannulation in thoracic aortic surgery in terms of perioperative outcomes; however, as the studies were limited, larger scale comparative studies are required to provide a solid evidence base for choosing optimal arterial cannulation site.

Sternal Wound Infections, Risk Factors and Management - How Far Are We? A Literature Review.

Sternal wound infection (SWI) is one of the potential complications post cardiac surgery, and despite refined surgical techniques such as smaller incisions, antibiotic therapy, and optimised glycaemic control, the incidence rate is between <1% in elective cases with low risk factors and as high as 25% in patients with extensive risk factors. The presence of SWI will increase the perioperative morbidity and mortality rates and prolong the patient's hospital stay, therefore the prevention and diagnosis with appropriate management of such adverse outcomes at an early stage is important to prevent further progression as it can be fatal when the mediastinal structures are affected. Currently, the diagnosis typically consists of three main stages: clinical, biochemical including microbiology studies and imaging studies. In the current health care system, the use of computed tomography (CT) and magnetic resonance imaging (MRI) is valuable to define mediastinal abnormalities and can also help find the source of a descending infection. Management is through methods such as antibiotic therapy, surgical debridement, reconstruction with soft tissue flap coverage, sternal plating, and sternectomy. In this literature review, we aim to summarise current literature evidence behind appropriately diagnosing such a catastrophe.