An evaluation of intravenous digital subtraction angiography in assessing lower limb ischaemia.

Intravenous digital subtraction angiography (IV DSA) is a relatively simple, minimally invasive technique which can be performed on an out-patient basis. On the other hand it lacks the clarity and definition of conventional angiography (CA). This paper evaluates the usefulness of IV DSA in planning intervention in lower limb ischaemia. Between January 1988 and June 1989, 492 IV DSAs were performed on patients with peripheral vascular disease. The results of the DSA were compatible with the clinical impression in 480 cases and management was planned accordingly. In 12 (2.4%) the DSA was inconclusive (failure to confirm clinical findings in three, insufficient information in six, technical failure in three), and CA was performed. This resulted in six patients having an arterial reconstruction who would not otherwise have done so. One hundred and six of the 480 cases routinely had a CA, in addition to the IV DSA prior to planned angioplasty or intra-arterial thrombolysis. These provided a direct comparison between the two techniques. In 99 (93%) the findings of the two procedures were identical. Significant lesions (not seen on DSA) were identified by CA in four patients, (false: -ve 3.8%) two of which were successfully dealt with by angioplasty. In two patients lesions were not confirmed (false: +ve 1.9%) and in one, disease progression was noted. Thus of the 106 patients, two (1.9%) were found to have lesions on CA, but not on IV DSA, which were successfully treated. IV DSA is satisfactory in most patients with lower limb ischaemia. Its imperfections are more than outweighed by its simplicity and patient acceptability.