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Management of severe ischaemia of the leg

The incidence of severe ischaemia of the leg, defined by the presence of rest/night pain and/or tissue loss (ulceration, gangrene), is estimated at 50–100 per 100 000 per year1. Ageing populations, the increasing prevalence of diabetes and a failure to control tobacco consumption means that the numbers of patients presenting worldwide with this condition are likely to increase2. Severe ischaemia can be treated medically, by amputation, or by revascularization using surgical or endovascular methods. Medical therapy can relieve symptoms in the short term but it is usually only a temporizing or palliative measure. Furthermore, as patients undergoing amputation have an extremely poor prognosis, it seems appropriate to try to revascularize the limb whenever possible. Unfortunately, the literature on the subject largely comprises uncontrolled hospital-based series describing attempts at limb salvage in highly selected patients3; there is little information on what proportion of patients undergo revascularization and how they fare4. There has also been much controversy about the relative merits of bypass surgery and angioplasty5,6. In the recently published bypass versus angioplasty in severe ischaemia of the leg (BASIL) trial, 452 patients presenting to 27 UK hospitals with severe ischaemia of the leg due to infra-inguinal disease were randomly allocated to surgery or angioplasty7. The trial ran for 5·5 years, at which point 38 (8 per cent) patients were alive with amputation of the trial leg, 36 (8 per cent) were dead after amputation, 130 (29 per cent) were dead without amputation, and 248 (55 per cent) were alive without amputation. Up to 2 years after randomization, the two strategies did not differ significantly in terms of amputation-free survival or healthrelated quality of life (HRQL). At first glance, these data appear to suggest that such patients can reasonably be treated by either method in the first instance depending on local preferences and expertise. However, when one studies the outcomes in more detail over time the interpretation becomes more complex. Balloon angioplasty was associated with a much higher rate of immediate failure (20 per cent) than surgery (3 per cent). Furthermore, of the successful angioplasties, 27 per cent were judged to have failed clinically within the first 12 months and over threequarters of these patients went on to have limb salvage surgery. By contrast, the 12-month reintervention rate after operation was 17 per cent. A third of these patients went on to have further surgery and the rest had angioplasty, usually to correct a vein graft stenosis detected on surveillance. So, although on an intention-to-treat basis limb salvage appears to be similar using both strategies, this equivalence depends on a significant number of patients randomized to angioplasty crossing over to surgery. Surgery was associated with a significantly higher rate of early morbidity (57 versus 41 per cent) but not mortality (6 versus 3 per cent). It was also associated with a longer hospital stay over the first 12 months (mean 46 versus 36 days), resulting in higher costs per patient (£23 322 versus £17 419). After 2 years, surgery was associated with a significantly reduced risk of future amputation and/or death, but this apparent benefit should be viewed with caution as it results from a post hoc analysis and the number of events was relatively small. The trial cohort is being followed up for another 3 years to determine definitively whether, despite the increased short-term morbidity and cost, surgery is the more clinically and cost-effective treatment. To determine the generalizability of the BASIL trial to overall management of severe leg ischaemia, data were collected prospectively on all patients presenting to the six top recruiting centres. Almost half of these patients were deemed unsuitable for any form of revascularization because their disease was too advanced and/or the patient too frail. As many patients presenting with severe ischaemia are not treated in specialist vascular units and survey data were collected only on those patients selected for angiography, the overall rate of revascularization in the UK is almost certainly even lower. Given the compelling evidence base, one other unexpected and rather shocking observation from the BASIL trial was that most of these highestrisk patients had not been receiving best medical therapy before entry to the trial. Only a third were receiving cholesterol-lowering therapy and only two-thirds antiplatelet agents. One can only speculate about how many of these patients might not have developed critical ischaemia, lost their legs or died had their arterial disease