Use of magnetic resonance angiography for the preoperative evaluation of patients with infrainguinal arterial occlusive disease

Abstract

This study was designed to determine whether magnetic resonance angiography (MRA) will allow preoperative management decisions without the need for contrast arteriography in patients with lower extremity ischemia caused by infrainguinal arterial occlusive disease. Forty-five patients with lower extremity ischemia in 50 limbs were evaluated by both two-dimensional time-of-flight MRA and intraarterial digital subtraction angiography (DSA) between February 1992 and June 1995. Independent management plans were based on clinical presentation, pulse volume recordings, and separate reviews of the MRA and DSA. Of 50 limbs, 23 required arterial bypass, 19 percutaneous transluminal angioplasty, 5 patch angioplasty, and 3 amputation. MRA and DSA correlated exactly in 89.5% of infrainguinal arterial segments, whereas interpretations disagreed in 10.5% of arterial segments. Mismatches that had an influence on patient treatment decisions occurred in only 8 (2.3%) of 352 arterial segments. Independent MRA- and DSA-based revascularization plans agreed in 45 (90%) extremities. MRA predicted the level of arterial reconstruction in all 23 limbs that required arterial bypass. MRA identified focal stenoses amenable to percutaneous transluminal angioplasty in 18 (94.7%) of the 19 limbs that ultimately underwent percutaneous transluminal angioplasty. A strategy of preoperative planning by MRA with confirmatory intraoperative arteriography would represent a 31% cost savings per patient at our institution while eliminating the morbidity of preoperative DSA. When used in combination with the patient's physical examination and segmental limb pressures with plethysmography, MRA is sufficient for planning infrainguinal arterial bypass procedures and selecting patients for percutaneous transluminal angioplasty.