Volume 7, Number 1

Pushpinder Sidhu FRCSI Specialist Registrar, Cardiothoracic Surgery, Department of Cardiac Surgery, Royal Hospitals Trust, Belfast; Hugh O’Kane FRCS Consultant Cardiac Surgeon, Department of Cardiac Surgery, Royal Hospitals Trust, Belfast

Although the first mechanical valve was implanted in the descending aorta for a patient with aortic regurgitation, orthoptic mechanical heart-valve replacement surgery became possible with the advent of cardiopulmonary bypass in the mid-1950s Harken was credited with the first aortic valve replacement (AVR) in 1960, and Starr with the first mitral valve replacement (MVR), also in 1960. Both used caged ball valves. Shortly after this, caged disc valves were developed. In its early stages thromboembolism was a common feature – reported at up to 4% per year – and warfarin was the chief anticoagulant.

Myles Bradbury MB ChB MRCPCH Specialist Registrar, Department of Haematology, Birmingham Heartlands Hospital, Birmingham

A rare condition? The aetiology of deep vein thrombosis (DVT) is multifactorial, involving an interaction between congenital and acquired factors. Research into the causation of acquired factors has focused on both inducing a hypercoagulable state and promoting venous stasis – environmentally (immobility/postoperative) and structurally (mass effect).

RM Higgins MD FRCP Nephrologist, University Hospitals Coventry and Warwickshire, Coventry; M Vegad RCN Dialysis Nurse, University Hospitals Coventry and Warwickshire, Coventry

Dialysis is a treatment whereby waste and excess fluid is removed from the body. In haemodialysis, blood is removed from circulation at a rate of about 200 ml per minute and is passed through a blood pump and an artificial kidney in order to clean it (the artificial kidney has a surface area of up to 2 m2). The membrane within the artificial kidney activates complement, neutrophils and the coagulation cascade.

Carina Saxby MRCGP Specialist Registrar in Palliative Medicine, St Catherine’s Hospice, Scarborough

Venous thromboembolism (VTE) is common in advanced malignancy. In such cases anticoagulation is hazardous and less effective. Patients with advanced cancer may already be taking multiple medications so there is an increased risk of bleeding.

Peter Rose, Editor

Clinicians have struggled to produce a safe and user-friendly regimen for the commencement of oral anticoagulation. Initiation of warfarin therapy remains a continuing challenge as many clinicians continue to use loading dose regimens stored in the cerebral recesses from medical school days, many of which are distinctly unsafe. The problem is compounded by the ever increasing need to rapidly anticoagulate patients and minimise any delay in hospital discharge.