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In previous articles I have described how the speciality of Vascular Surgery is concerned with the diagnosis, assessment and treatment of conditions of the arteries, veins and lymphatics of every part of the body apart from the heart (cardiology/cardiac surgery) and the brain (neurology/neurosurgery).
Vascular surgery is a high-risk speciality for medicolegal claims because when problems occur they do so quickly and with severe limb and life-threatening complications.
My previous papers have provided a brief overview of vascular surgery, but in this article, I am going to concentrate on a common problem area for arterial disease – the legs. Medical negligence in this area frequently results in amputation of the limb and long- term disability requiring significant modifications to all areas of a claimant’s life including employment, social life, home life, relationships and life expectancy.
Arterial Conditions Affecting the Legs
In general, arteries carry blood rich in oxygen and nutrients to supply the muscles and tissues of the legs. In humans the muscles of the legs are much bigger and require much more arterial blood supply than the arms, therefore, arterial conditions such as atherosclerosis, which causes arterial narrowing/blockages, have much greater effect. Two situations significantly increase the blood requirement of the leg – exercise and injury/wound healing. Problems occur when the arterial blood requirement of a limb exceeds the ability of diseased arteries to meet that requirement. In exercise this means the muscles go into oxygen debt, produce lactic acid and seize-up – intermittent claudication. In injury/wound healing it means that healing does not occur and in fact wounds deteriorate and extend - the classic example is gangrene of a little toe which extends until the whole leg turns gangrenous. Therefore, all conditions which affect the arteries require timely and accurate assessment and treatment to avoid unnecessary pain and disability.
For the purpose of this article I am going to describe conditions according to the common areas of claims:
Acute conditions represent a sudden deterioration in blood supply. These can occur from intrinsic reasons such as an embolus from the heart or aorta, or extrinsic reasons such as a sharp transection of the artery or blunt injury such as overstretching of the arteries by unstable bone fractures and dislocations. In acute conditions there is no time for the body to adapt and, if the interruption to blood flow is complete, then there are six hours to restore arterial blood flow before significant muscle death occurs. Depending on anatomy, after 12-24 hours of ischaemia the limb frequently becomes non-viable. Therefore, delays in diagnosis and treatment are a common cause of disability and source of claims. Closed arterial injury associated with fractures can be easily missed, especially in cases of multiple trauma, and a high index of suspicion is essential to ensure prompt referral to vascular surgery.
Chronic conditions represent a gradual worsening in blood supply, which may go unrecognised by patient and doctors until a final deterioration such as a patch of dry gangrene or non-healing ulcer. The common cause of arterial problems is atherosclerosis (hardening of the arteries) caused by smoking, diabetes (particularly type 2 diabetes) and old age. While smoking is in decline the prevalence of obesity-related type 2 diabetes and old age is increasing. Chronic arterial disease develops over years. Classically, symptoms in the legs progress, as more arteries block off, deteriorating from pain in the muscles on walking (claudication), to pain in the feet at night as the nerves are deprived of oxygen, to pain in the feet all the time to, finally, non-healing ulcers and gangrene.
Diagnostic difficulties arise because some patients can progress straight to non-healing ulcers or gangrene without passing through the other stages. For example, non-mobile patients may never walk sufficiently to experience claudication, while diabetic patients with peripheral neuropathy may never experience pain in the feet due to decreased sensation.
The majority of type 2 diabetics will not die as a result of blood sugar abnormalities but due to heart attacks, strokes and peripheral arterial disease – in this regard type 2 diabetes can be considered more of a cardiovascular, atherosclerotic disease rather than an endocrine disorder.
Patients with chronic arterial disease may undergo acute deterioration when diseased arteries suddenly thrombose, resulting in critical ischaemia requiring urgent intervention to save the leg. The time scale for intervention is generally longer but may be more difficult to diagnose and treat. Sometimes, doctors who are used to seeing a patient with long- term, but stable, arterial disease, may not recognise that a small amount of further deterioration has resulted in the leg becoming critically ischaemic and fail to treat the situation with sufficient urgency.
Non-healing leg ulcers are a particular problem in both diabetics and the elderly. Whatever the cause, once the ulcer occurs the blood requirement of the limb to achieve healing increases significantly. If diseased arteries cannot supply the extra blood then healing never occurs unless the arterial supply can be improved. In the NHS, the majority of leg ulcers are managed in the community with treatment provided by nurses supervised by GPs who may have limited training of knowledge of peripheral vascular matters. There is NICE guidance regarding the management of leg ulcers and those that fail to heal in the community should be referred for specialist assessment within a given time- frame, but this advice is not always followed and this can be an important factor in leg ulcer related claims.
Complications of Treatment
The two main elements of the treatment of peripheral arterial disease are the specific lesions causing a reduction in blood flow and the management of the patient’s overall risk of cardiovascular events. In arterial patients, risk management substantially reduces the risk of death, heart attacks, strokes etc. and includes: lifestyle advice, blood pressure management, cholesterol/lipid lowering, antiplatelet agents etc. Failure to implement this management in patients with known arterial disease who go on to suffer an adverse cardiovascular event can be a source of claims.
Treatment of specific arterial lesions disease to improve blood flow includes: interventional procedures such as thrombolysis, balloon angioplasty/stenting and arterial operations including bypass surgery. These interventions are potentially high risk with potentially serious complications and side-effects, therefore, the consent process is particularly important especially with regard to the Montgomery judgement.
Thrombolysis is the administration of ‘clot busting’ medication directly into an artery to dissolve the occluding thrombus. The main complications include haemorrhage, damage to the arteries and failure to remove the thrombus. Thrombolysis may be considered appropriate if the limb is not immediately threatened and the clinicians feel there is sufficient time for the lysis to work. Even then, frequent assessment of the leg during lysis is required to ensure that the limb is not becoming non-viable. One of the worst outcomes is to eventually clear the arteries of thrombus but the leg muscles are dead, requiring amputation.
Balloon angioplasty is an interventional radiology procedure involving the direct puncture of an artery to introduce an angioplasty balloon catheter to stretch open a stenosed or blocked artery. Depending on the anatomical site, a metal stent can then be inserted to keep the artery open. Complications include bleeding, damage to the artery, failure to get across the lesion, embolization (where thrombus is dislodged and blocks more distal arteries), early re-occlusion and allergic reaction to radiological contrast solutions. Angioplasty is often performed under local anaesthetic and is less invasive than surgery but, once again, valuable time may be wasted at multiple attempts at angioplasty and the opportunity for limb-saving surgery is missed.
All arterial surgery may be considered major surgery. Examples of arterial surgery include endarterectomy and bypass surgery. Surgery is generally employed when there are extensive occlusions of the leg arteries, the anatomical site means that the lesions are not suitable for angioplasty or the urgency of the situation means that other forms of treatment cannot by tried. Success depends on a high level of technical skill and close monitoring in the post-operative period to detect early complications such as bypass occlusion causing further ischaemia. Poor clinical decision making, technical errors and failure of post-operative care are common sources of claims.
Amputation
Leg amputation is frequently considered by patients to be an unpopular, disabling and disfiguring operation, but can be both life-saving and transformative when arterial disease and ischaemia are too extensive.
However, patients are right to believe that amputation is a major life-changing event, which affects all aspects of life including mobility, occupation, home life, personal care, transport, leisure activities, relationships, holidays and reduced life-expectancy. Despite the inspiring feats of para-Olympian athletes the sad truth is that many elderly amputees will never manage to mobilise fully with a prosthetic limb and many rely predominantly on a wheelchair and have extensive care needs for all aspects of daily living. Therefore, when amputation occurs as the result of negligence the resulting claims can be substantial.
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