Expert Witness – Vascular Surgery
Talking to Lawyer Monthly on the complexities of vascular surgery, the processes involved in the role of an expert witness, and the evolution of this medical field over the years, is Professor Charles McCollum, representing the University of Manchester, UK, and Isobar Compression, a UK-based developer of garments purposed for alleviating and preventing deep vein thrombosis and similar conditions.
Prof. McCollum explains the ins and outs of clinical negligence in this field, reveals the background behind his longstanding expertise, and gives insight on the solutions available for DVT and PE, including the development of Isobar Compression and its highly effective use in a variety of sectors.
When did you first provide advice as a medical expert?
In 1989 I was asked by now Lord Daniel Brennan QC, acting for the Claimant, to offer a second opinion on a case where an eminent Vascular Surgeon was accused of undertaking a ‘research procedure’ without seeking informed consent. The original advice received from a well-known expert in vascular surgery was that the Claimant had suffered a serious injury, with a marked deterioration in venous function, as a consequence of ligating an incompetent deep vein (at that time this was an unusual thing to do!). I advised that it was common at that time for renowned academic surgeons to carry out new and/or unusual procedures in a bid to push back the frontiers of medicine. As I walked down Middle Temple Lane with the well-known vascular expert after council’s conference, I was informed that my role was to get this case to Court and then to do my best to support the Claimant once there. Perplexed, I telephoned my instructing solicitor to find out if I had misunderstood her instruction. I was greatly relieved to be told that instructing solicitors required independent medical advice whether or not the case had merit. I am immensely grateful to her and, as a result of this approach, built up a substantial and intellectually rewarding medico-legal practice.
What have been the principal changes in the range of advice that you been asked to give in the 17 years since then?
During the first 10 years of working as a medico-legal expert, I received large numbers of personal injury instructions; often involving injuries that caused deep vein thrombosis (DVT) and/ or pulmonary embolism (PE). As my reputation steadily increased, I was increasingly asked to consider clinical negligence. It quickly became clear that I could not expect general surgeons with the vascular interest to have the same level of experience that I had in treating rare, complex or unusual vascular problems. However, any competent clinician should be able to recognise when they are out of their depth and need to refer a patient to a specialist centre in order to avoid disabling complications.
As my medicolegal practice increased, I made the difficult decision that I should discontinue personal injury work so that I could still focus on my academic role as Professor of Surgery. I appointed Richard Williams-Lees, an unregistered Barrister, to establish Cardiovascular Advisors Ltd (CVA) with experts in cardiology, stroke medicine, haematology, thrombosis and diabetes, to provide solicitors with access to specialist advice on all areas of cardiovascular medicine.
From your experience, what are the most frequent types of clinical negligence claims?
Overall, 21% of my clinical negligence practice relates to the failure to prevent, diagnose or promptly treat DVT or PE. Many young adults die unnecessarily of PE, or suffer debilitating life-long symptoms due to irreparable damage to leg veins. Clinical assessment alone is unreliable and the consequences of delayed diagnosis are serious for patients and their families.
The next most frequent negligence claims in my practice (12%) are failures to diagnose arterial disease or thrombosis in limb arteries resulting in amputation and significant disability. Unfortunately, and often tragically, symptoms that would be diagnosed as peripheral artery disease or thrombosis in the elderly are often missed in younger adults. GPs, who receive brilliant training in the UK, simply forget to attribute calf or foot pain in young adults to artery disease. Common errors are that GPs or trainee doctors feel pulses that are not there or mistake the cause of a red foot as infection or gout. In the ‘sunset foot’ (indicating appearance and prognosis) the microcirculation has dilated and filled with blood to try to compensate for blocked arteries in the legs, giving the forefoot a red appearance. Our medical schools should teach students to measure ankle arterial pressure using inexpensive Doppler ultrasound rather than feeling foot pulses and to elevate the red foot (it will turn white if ischaemic).
What are the major changes that you have seen in clinical negligence claims and what changes do you expect to see in the future?
The developing bureaucracy of treatment protocols, guidelines and serious untoward incident reports has aggravated the explosion in clinical negligence claims over the last decade. I also think that the scandal surrounding the Mid Staffordshire NHS Foundation Trust (The Francis Report, 2013) was fundamental to changing patients and their families’ attitudes to clinical errors they previously accepted as mistakes. Any breach in a guideline may now be the subject of claim, with many claims based on the serious untoward incident reports prepared by nurses at the defending hospital. Nursing experts in particular treat the Nursing and Midwifery Guidelines as minimum standards of care when the reality is that these are standards of excellence. As an example, a nursing expert is unlikely to accept that a patient at high risk of developing a pressure sore developed such as sore as a consequence of this increased risk rather than negligent care.
Regrettably, the advances in care promoted by the National Institute of Clinical Excellence (NICE) are becoming a “rule book”. Fifteen years ago, it was unusual for diabetic patients to claim breach of duty when they suffered amputation of a toe, foot or even leg. As NICE guidelines state that any new ulcer requires immediate referral to a multidisciplinary diabetic foot clinic, there are now multiple claims based on breaching these guidelines. There is little recognition that poorly controlled Type I diabetes, particularly in heavy smoking patients, carries a high risk of major limb amputation in the third and fourth decades of life. The experience of vascular surgeons is that referral to a vascular unit indicates vascular problems and a deteriorating prognosis. Diabetic specialists have a more optimistic view on prognosis for diabetic foot ulceration based on their practice in patients without diabetic vascular problems. Forefoot or major limb amputation is the most rapidly growing sector in my clinical negligence practice: It represented 9% of my last 100 clinical negligence cases and may well rise to 15-20% in the next decade.
You said that DVT and PE are the most common conditions leading to litigation in the UK, is this also changing?
In the past, the vast majority of personal injury instructions have related to DVT or PE caused by injury in the work place or in road traffic accidents. However, in recent years I have received a number of instructions where employees have suffered DVT or PE as a consequence of frequent or long-haul flights during the course of their employment.
There has been a consistent increase in the number of clinical negligence claims caused by failures to prevent, diagnose or effectively treat DVT or PE. These frequently involve young adults, such as young women taking the combined oral contraceptive pill, who suffer a fatal PE after tell-tale signs of DVT have been missed by a GP or by hospital staff. Regrettably, it is well known that the clinical signs of DVT and PE are entirely unreliable and this diagnosis must be considered in any patient with unexplained calf or leg pain, particularly if there is swelling. A great deal of weight is placed on the ‘Wells Score’, which is used to stratify the patient’s individual risk; but as this score is based on clinical symptoms and signs, it is inevitably unreliable. Doctors should have a very low threshold for taking venous blood to measure D-dimer, which is a non-specific measure of thrombotic activity that rises in patients with VTE, but also may be raised following surgery, injury or inflammation. Generally, doctors should initiate anticoagulation on any suspicion of VTE and arrange definitive investigation by high-definition colour duplex ultrasound or, in the case of PE, with CT pulmonary angiography (CTPA). Delaying treatment until after the diagnosis has been confirmed is a frequent cause of long-term sequalae or even death from PE.
What are the treatments for DVT/PE?
The principal objective of treatment is to prevent a DVT extending to cause long-term symptoms or detaching to become a PE. Providing full, immediate anticoagulation is achieved intravenously, followed by adequate oral anticoagulation using warfarin or one of the novel oral anticoagulants, most patients are protected from complications. There is good evidence that wellfitting elastic stockings delivering 25 mmHg compression at the ankle (equivalent to class II BNF on our NHS) reduces the risk of long-term symptoms, particularly in those patients where treatment is initiated early after the onset of symptoms. Long-term symptoms are associated with delayed diagnosis or treatment. We also know that carefully-fitted elastic stockings worn for two years following DVT reduces the risk of long-term disability.
How did you get involved in Isobar Compression?
I was invited to review a major grant application by the Wellcome Trust a little over a decade ago. This application proposed 3-D imaging of the limb to guide the production of elastic garments that fit perfectly, and deliver whatever pressure is prescribed by the doctor. I recognised that this was the only technology in the world that would allow research on the ideal pressures needed for each clinical indication: Including, the prevention of DVT in frequent or long-haul flight and the treatment of varicose veins, venous insufficiency, lymphoedema and venous ulceration. It is also the only technology able to precisely manufacture Isobar stockings to the exact profile of each leg using computer-controlled knitting machines. It recognises that there is a difference between the right and left leg and that the leg is not round. The Textiles Department’s application did not include a clinical partner and the Wellcome Trust agreed with my suggestion that they resubmit their application with me as a co-applicant. We were awarded a £0.5 million grant that initiated what has become our unique Isobar Compression technology that should become the world leader in preventing DVT while travelling and in hospital inpatients. In my opinion, it will also become the most effective treatment for varicose veins, venous insufficiency, venous ulceration, lower leg wounds, ankle fractures and sprains and for the control of swelling in the elderly and patients with lymphoedema.
Finally, there was much talk of compression at the Rio Olympics. What use has compression in elite sport?
There is growing evidence to show that compression socks and arm sleeves reduce delayed onset muscle soreness (DOMS), allowing athletes to quickly recover and return to training. Isobar is working with many national sports governing bodies, as well as elite and amateur athletes to supply compression socks to enhance performance, recovery after training and to prevent DVT as a result of travel. Wearing compression during travel also reduces leg swelling, allowing athletes to resume training as quickly as possible after a long journey.
Elite athletes travel widely by coach within their own country for matches or competition or by air for overseas training camps and international competition. They are at high risk of DVT due to stagnant venous blood flow in well-developed calf muscles. Amateur athletes who compete in cycling or running races are also at risk as they return, often dehydrated, to their day jobs sitting in an office or driving long distances. Isobar supplied over 100 athletes in Rio with exact-fit, bespoke compression socks to mitigate the risk of DVT during flight. The gold and silver medal winning Brownlee Brothers commented: “Coming from a medical family, we know a DVT isn’t worth the risk and could end our careers. Isobar socks fit perfectly and are comfortable enough to wear all day. The precise compression level is based on clinical research, so we know they work really well.” Isobar Compression offers a 3D scan service to customers, using the scan data to stitch custom-fit, bespoke compression socks and set the correct pressure grade to mitigate DVT risk. Find out more at www.isobar-compression.com.
