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Hoskote A.,Institute of Child Health | Burch M.,Cardiothoracic Unit
Pediatric Nephrology | Year: 2015

Significant advances in cardiac intensive care including extracorporeal life support have enabled children with complex congenital heart disease and end-stage heart failure to be supported while awaiting transplantation. With an increasing number of survivors after heart transplantation in children, the complications from long-term immunosuppression, including renal insufficiency, are becoming more apparent. Severe renal dysfunction after heart transplant is defined by a serum creatinine level >2.5 mg/dL (221 μmol/L), and/or need for dialysis or renal transplant. The degree of renal dysfunction is variable and is progressive over time. About 3–10 % of heart transplant recipients will go on to develop severe renal dysfunction within the first 10 years post-transplantation. Multiple risk factors for chronic kidney disease post-transplant have been identified, which include pre-transplant worsening renal function, recipient demographics and morbidity, peri-transplant haemodynamics and long-term exposure to calcineurin inhibitors. Renal insufficiency increases the risk of post-transplant morbidity and mortality. Hence, screening for renal dysfunction pre-, peri- and post-transplantation is important. Early and timely detection of renal insufficiency may help minimize renal insults, and allow prompt implementation of renoprotective strategies. Close monitoring and pre-emptive management of renal dysfunction is an integral aspect of peri-transplant and subsequent post-transplant long-term care. © 2014, The Author(s).

Madden B.P.,Cardiothoracic Unit
European Cardiology Review | Year: 2015

Pulmonary hypertension is defined by a mean pulmonary artery pressure of > 25 mmHg at rest or 30 mmHg during exercise. There are many causes and currently diseases causing the condition are classified into five groups. The greatest elevation in pulmonary arterial pressure is found among those disorders in group 1 (known as pulmonary arterial hypertension [PAH]) and research and targeted therapy has focused on this group in particular, although patients in group 4 (chronic thromboembolic PH [CTEPH]) also receive advanced pulmonary vasodilator therapy. The symptoms of PH are often vague and the diagnosis is frequently missed or delayed. Efforts are therefore being made to improve awareness of PH among clinicians to enable prompt referral to a PH unit to confirm the diagnosis and instigate appropriate therapy. Multi-disciplinary team (MDT) discussion is necessary if patients with PH require surgical intervention or become pregnant. For patients in the other PH groups, treatment is usually concentrated on the primary disorder. A small number of patients with PAH will respond to calcium-channel-blocking agents. Specific targeted therapy is often given in combination depending on the patients functional performance status. Available agents include phosphodiesterase type V inhibitors, endothelin receptor antagonists, prostglandin analogues and nitric oxide. Many novel agents are under review. For carefully selected patients surgical options, include lung transplantation, pulmonary thromboendarterectomy and atrial septostomy.

Madden B.P.,Cardiothoracic Unit
European Cardiology | Year: 2015

Pulmonary hypertension is said to occur when the mean pulmonary arterial pressure exceeds 25 mmHg at rest or 30 mmHg during exercise. There are many causes but the term Pulmonary arterial hypertension (PAH) is used to describe a rare group of illnesses that share histopathological similarities in the small muscularised pulmonary arterioles leading to vascular remodelling (plexogenic pulmonary arteriopathy) and progressive elevation in the pulmonary vascular resistance. Left untreated, patients die as a consequence of right heart failure and the mortality approaches that of commonly encountered malignancies. There is no effective cure. Most treatment for PAH patients has focused on the endothelial cell vascular dysfunction known to occur in these disorders and indeed agents such as endothelin receptor antagonists, phosphodiesterase pathway V inhibitors and prostacyclin analogues have been shown to improve morbidity and delay rate of deterioration. More recently evidence has emerged that they may have a positive impact on survival. These agents have also been applied to treat patients with chronic thromboembolic pulmonary hypertension (CTEPH) and selected patients with CTEPH may also benefit from pulmonary thromboendarterectomy. For a small number of patients with PAH lung transplantation may be considered.

Okonta K.E.,University of Ibadan | Adamu Y.B.,Cardiothoracic Unit
Interactive Cardiovascular and Thoracic Surgery | Year: 2012

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether the of vegetations in endocarditis is an indication for surgery. Altogether, 102 papers were found using the reported search; 16 papers were identified that provided the best evidence to answer the question. The authors, journal, date, country of publication, patient group, study type, relevant outcomes and results were tabulated. The vegetation size was classified into small (<5 mm), medium (5-9 mm), or large (≥10 mm) using echocardiography and a vegetation size of ≥10 mm was a predictor of embolic events and increased mortality in most of the studies with left-sided infective endocarditis. For large vegetations - that commonly resulted from the failure of antibiotics to decrease the vegetation size during 4-8 weeks' therapy - and complications such as perivalvular abscess formation, valvular destruction and persistent pyrexia necessitated surgical intervention. In a multicentre prospective cohort study of 384 consecutive patients with infective endocarditis, it was observed that a vegetation size of >10 mm and severe vegetation mobility were predictors of new embolic events. Equally, a meta-analysis showed that the echocardiographic detection of a vegetation size of ≥10 mm in patients with left-sided infective endocarditis posed significantly increased risk of embolic events. In another prospective cohort study of 211 patients, it was observed that there was an increased risk of embolization with vegetations of ≥10 mm. In similarly another study of 178 consecutive patients with infective endodarditis assessed by echocardiographic study, it was found out that there was a significantly higher incidence of embolism with a vegetation size >10 mm (60%, P<0.001). When using the area of the vegetation, a vegetation size of >1.8 cm2 predicted the development of a complication. Assuming that the vegetation was a sphere, the calculated diameter will be 8 mm when using 4Ωr2 for the area. However, for right-sided infection endocarditis, a vegetation size of >20 mm was associated with a higher mortality when compared with a vegetation size of ≤20 mm. There is strong evidence to suggest that a vegetation size of ≥10 mm especially for left-sided infective endocarditis is an indication for surgery. © 2012 The Author. Published by Oxford University Press on behalf of the European Association for Cardio-thoracic Surgery. All rights reserved.

Fishman J.M.,University College London | De Coppi P.,University College London | Elliott M.J.,Cardiothoracic Unit | Atala A.,Wake forest University | And 2 more authors.
Expert Opinion on Biological Therapy | Year: 2011

Prosthetic replacements, autologous tissue transfer and allografts have so far failed to offer functional solutions for the treatment of long circumferential tracheal defects and loss of a functioning larynx. Interest has therefore turned increasingly to the field of tissue-engineering which applies the principles and methods of bioengineering, material science, cell transplantation and life sciences in an effort to develop in vitro biological substitutes able to restore, maintain or improve tissue and organ function. Areas covered: This article gives an overview of the tissue-engineering approach to airway replacement and will describe the encouraging results obtained so far in tracheal regeneration. The recent advances in the field of tissue-engineering have provided a new attractive approach towards the concept of functional substitutes and may represent an alternative to the shortage of suitable grafts for reconstructive airway surgery. We summarize fundamental questions, as well as future directions in airway tissue engineering. Expert opinion: The replacement of active movement, as would be necessary to replace an entire larynx introduces another order of magnitude of complexity, although progress in this area is starting to bear fruit. In addition, the stem cell field is advancing rapidly, opening new avenues for this type of therapy. © 2011 Informa UK, Ltd.

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