Guidance
4 Research recommendations
- 4.1 Angioplasty versus bypass surgery for treating people with critical limb ischaemia caused by disease of the infra‑geniculate arteries
- 4.2 Supervised exercise programmes for treating people with intermittent claudication
- 4.3 Patient attitudes and beliefs about peripheral arterial disease
- 4.4 Primary versus secondary stenting for treating people with critical limb ischaemia caused by disease of the infra‑geniculate arteries
- 4.5 Chemical sympathectomy for managing critical limb ischaemic pain
4 Research recommendations
The Guideline Development Group has made the following recommendations for research, based on its review of evidence, to improve NICE guidance and patient care in the future. The Guideline Development Group's full set of research recommendations is detailed in the full guideline (see section 5).
4.1 Angioplasty versus bypass surgery for treating people with critical limb ischaemia caused by disease of the infra‑geniculate arteries
What is the clinical and cost effectiveness of a 'bypass surgery first' strategy compared with an 'angioplasty first' strategy for treating people with critical limb ischaemia caused by disease of the infra‑geniculate (below the knee) arteries?
Why this is important
Many people with critical limb ischaemia, especially those with diabetic vascular disease, also have disease of the infra‑geniculate (below the knee) arteries in the calf. For many years, the standard of care has been bypass surgery. Although such surgery may be associated with significant morbidity, the resulting long‑term amputation‑free survival rates are generally good. In recent years there has been a trend towards treating infra‑geniculate disease with angioplasty, on the grounds that it is associated with less morbidity than surgery. However, this change in practice is not evidence‑based, and serious concerns remain about the durability of angioplasty in this anatomical area. A multicentre, randomised controlled trial with a full health economic analysis is required to address this. The primary endpoint should be amputation‑free survival, with secondary endpoints including overall survival, health‑related quality of life, healing of tissue loss, and relief of ischaemic pain.
4.2 Supervised exercise programmes for treating people with intermittent claudication
What is the clinical and cost effectiveness of supervised exercise programmes compared with unsupervised exercise for treating people with intermittent claudication, taking into account the effects on long‑term outcomes and continuing levels of exercise?
Why this is important
Research has shown that taking part in exercise and physical activity can lead to improvements in symptoms in the short term for people with intermittent claudication. However, the benefits of exercise are quickly lost if it is not frequent and regular. Supervised exercise programmes have been shown to produce superior results when compared with advice to exercise (unsupervised) in the short term, but they are more expensive, and there is a lack of robust evidence on long‑term effectiveness. A community‑based randomised controlled trial is required to compare the long‑term clinical and cost effectiveness of a supervised exercise programme and unsupervised exercise. The trial should enrol people with peripheral arterial disease‑related claudication, but exclude those with previous endovascular or surgical interventions. The primary outcome measure should be maximal walking distance, with secondary outcome measures including quality of life, function, levels of uptake of exercise programmes and long‑term engagement in physical activity.
4.3 Patient attitudes and beliefs about peripheral arterial disease
What is the effect of people's attitudes and beliefs about their peripheral arterial disease on the management and outcome of their condition?
Why this is important
The evidence reviewed suggested that, among people with peripheral arterial disease, there is a lack of understanding of the causes of the disease, a lack of belief that lifestyle interventions will have a positive impact on disease outcomes, and unrealistic expectations of the outcome of surgical interventions. Much of the research has been conducted on the subpopulation of people with peripheral arterial disease who have been referred for surgical intervention, but little evidence is available for the majority of people diagnosed with peripheral arterial disease in a primary care setting. Research is required to further investigate attitudes and beliefs in relation to peripheral arterial disease, interventions that might influence these and how these may have an impact on behavioural changes in relation to risk factors for peripheral arterial disease, attitudes to intervention and clinical outcomes.
4.4 Primary versus secondary stenting for treating people with critical limb ischaemia caused by disease of the infra‑geniculate arteries
What is the clinical and cost effectiveness of selective stent placement compared with angioplasty plus primary stent placement for treating people with critical limb ischaemia caused by disease of the infra‑geniculate arteries?
Why this is important
Studies comparing angioplasty plus selective stent placement with primary stent placement have been limited to the aorto‑iliac and femoro‑popliteal segment. There is also a significant group of people with critical ischaemia caused by disease of the infra‑geniculate vessels in which there is a potential for endovascular treatment. Infra‑geniculate disease is more complex to treat by endovascular means, and the risks and benefits of different treatment options may differ from those for the more proximal vessels. A multicentre, randomised controlled trial with a full health economic analysis is required to address the optimum policy as regards the choice of method for angioplasty and stent placement for the infra‑geniculate arteries. The primary endpoint should be amputation‑free survival, with secondary endpoints including overall survival, re‑intervention rates, health‑related quality of life, healing of tissue loss, and relief of ischaemic pain.
4.5 Chemical sympathectomy for managing critical limb ischaemic pain
What is the clinical and cost effectiveness of chemical sympathectomy in comparison with other methods of pain control for managing critical limb ischaemic pain?
Why this is important
Approximately 1 in 5 people with critical limb ischaemia cannot be offered procedures to improve the blood supply to their leg because of either the pattern of their disease or other comorbidities. In this group the therapeutic options are pain control or primary amputation. Chemical lumbar sympathectomy, which involves the destruction of the lumbar sympathetic chain (usually the L2 and L3 ganglia), has been suggested to reduce pain and improve wound healing, and may prevent amputation in some patients. Initially achieved surgically, it is now most commonly performed using chemical agents such as phenol to destroy the lumbar sympathetic chain. Despite having been used for over 60 years, the role of chemical lumbar sympathectomy remains unclear. Improvement in skin blood flow and modification of pain perception control have been demonstrated, and this has prompted the use of chemical lumbar sympathectomy for treating a range of conditions such as regional pain syndrome, vasospastic conditions and critical limb ischaemia. However, in critical limb ischaemia the use of chemical lumbar sympathectomy varies widely between units in England, the mode of action and indications are unclear, and there is currently no randomised controlled trial evidence demonstrating its clinical value. Therefore a randomised control trial comparing chemical lumbar sympathectomy with other methods of pain relief is recommended.