DUPLEX ULTRASOUND SCANNING DEFINES OPERATIVE STRATEGIES FOR PATIENTS WITH LIMB-THREATENING ISCHEMIA

Purpose: To characterize the accuracy of color-now duplex ultrasound ( DUS) in planning lower extremity revascularization procedures, we pros pectively compared operations predicted by means of DUS arterial scann ing (DUSAS) and operations predicted by means of conventional angiogra phy (CA) with actual operations performed in 36 patients undergoing 40 vascular reconstructions for critical (grade II/III) lower extremity ischemia. Methods: All patients were examined with lower extremity DUS AS followed by CA. DUSAS was performed from the aorta to the pedal ves sels of the affected extremity Adequacy of inflow was assessed, and th e best distal target vessel with continuous, unobstructed flow was def ined. An operative prediction was made and recorded based upon the DUS AS findings, and in a blinded fashion, based upon subsequent CA. The M cNemar test for comparing correlated proportions was applied to test f or the statistical significance of the difference (P < .05) between co rrect operations predicted by DUSAS and CA. Results: Of the actual ope rations performed, 83% were correctly predicted by means of DUSAS (95% CI; range, 77% to 89%). Seven operations were incorrectly predicted w ith DUSAS. Of the actual operations performed, 90% were correctly pred icted by means of CA (95% CI; range, 81% to 99%). Four operations were incorrectly predicted with CA. The McNemar test determined that the d ifference between correct operations predicted by means of DUSAS and c orrect operations predicted by means of CA was not statistically signi ficant (P = .50). Conclusions: With few exceptions, DUSAS can be used to reliably predict infrainguinal reconstruction strategies. Vessels d efined as adequate with DUSAS are rarely unfit for bypass. Prospective investigation of lower extremity revascularization based solely upon DUSAS is warranted.