ABSTRACT
BACKGROUND: Acute limb ischemia (ALI) represents an emergency in which delayed intervention results in significant morbidity, and potentially, death. PURPOSE: To assess the role of duplex in differentiating embolic from thrombotic ALI. METHODS AND MATERIALS: We prospectively recruited 57 patients; with 62 non-traumatic ALI. We measured the diameter at the occluded site (dO) and the corresponding contralateral healthy side (dC). The absolute (∆) and percent change (∆%) between the two diameters were calculated as: (dO-dC) and [(∆/dC)×100] respectively. According to the reference standard (contrast angiography or surgery), limbs were classified into embolic (E-group:37 limbs) and thrombotic (T-group:25 limbs) groups. Postoperative duplex was done in 34 patients after embolectomy and the absolute (∆P) and percent change (∆P%) between the postoperative (dP) and preoperative (dO) diameters at the occlusion were calculated as: (dP-dO) and [(∆P/dO)×100] respectively. RESULTS: The baseline clinical characteristics were similar between both groups. However, in the E-group, (∆%) was 21.96±17.53% vs. -11.03±16.16% in the T-group, (p<0.001). A cutoff value of >1.41% for (∆%) had 100% sensitivity and 76% specificity for the diagnosis of embolic vs. thrombotic occlusion with AUC 0.95 (95% CI: 0.901-0.999, p<0.00l). Postoperatively (∆P%) was -11.8±8.2% with a significant negative correlation found between (∆) and (∆P); Spearman's coefficient (rho)=-0.912, P<0.001. CONCLUSIONS: A cut off value of 1.41% as percent dilatation or diminution in the diameter of occluded artery is the most important duplex sign for predicting embolic or thrombotic ALI respectively. Postoperative reduction in the diameter of occluded artery after embolectomy confirms this sign.
