Background: There is some evidence that the early outcome of major amputation is worse after failed thromboembolectomy, but the risk factors and results of amputation done for acute ischaemia have never been compared with those for chronic ischaemia in a large series of patients.
Method: Retrospective review of 30 day outcome for all 322 primary amputations done for arterial disease during 1992-8. There were 286 patients (163 male; median age 76 years) who had 270 amputations for chronic ischaemia and 52 for acute ischaemia.
Results: The acute group had higher prevalences of cardiac disease (48% versus 29%-p<0.02), limiting pulmonary disease (27% versus 13%-p<0.02) and ASA grades 4 and 5 (27% versus 14%-p<0.05). Amputation below the knee was less common after acute ischaemia (31% versus 60%-p<0.001). There were trends towards more revisions (19% versus 11%) and higher mortality (25% versus 19%) in the acute group but neither reached statistical significance.
Conclusion: Patients having major amputations for acute ischaemia have higher levels of pre-existing comorbidity than those with chronic ischaemia and are twice as likely to require amputation above the knee. They should be managed as a particularly high risk group.