Abstract
BACKGROUND: Visceral malperfusion is a serious complication of acute aortic dissection. Currently, diagnosis relies on signs of end-organ failure, which may be clinically obscure and delay crucial treatment. OBJECTIVE: The aim was to investigate external iliac (IA) and superior mesenteric artery (SMA) pressures in cases where both vessels originate exclusively from the true lumen to develop and validate a novel early indicator of visceral malperfusion. METHODS: Endovascular pressure measurements from 488 patients with acute aortic dissection were analyzed. Exclusion criteria included static obstruction of the branch vessel or substantial re-entry tear below the SMA origin. RESULTS: In acute type A aortic dissection, 69 out of 244 (28.3%) patients had at least 1 common IA and the SMA with exclusive true lumen perfusion. Among all patients with acute type A aortic dissection, 41 (16.8%) patients with 49 external IA pressure measurements met inclusion criteria. Pressures in right external IA (n = 27) and left external IA (n = 22) correlated significantly with SMA perfusion pressure (r (2) = 0.86 [95% CI, 0.71-0.93; P = 1.03(E-08)] and r (2) = 0.86 [95% CI, 0.69-0.94; P = 2.85(E-07)], respectively).In settings of acute type B aortic dissection, 81 out of 244 (33.2%) patients had at least 1 common IA and the SMA with exclusive true lumen perfusion. Among all patients with acute type B aortic dissection, 35 (14.3%) patients with 44 external IA pressure measurements met inclusion criteria. The right external IA (n = 24) and left external IA (n = 20) pressures correlated significantly with SMA perfusion pressure (r (2) = 0.92 [95% CI, 0.83-0.97; P = 1.(59E-10)] and r (2) = 0.87 [95% CI, 0.70-0.95; P = 6.12(E-07)], respectively). CONCLUSIONS: In acute aortic dissection where the SMA and a common IA are supplied exclusively by the true lumen, external IA systolic pressures correlate significantly with SMA systolic pressures. In this group, therefore, clinical loss of the femoral pulse likely indicates significantly decreased SMA pressures, raising concern for visceral malperfusion, possibly before visceral enzymes can respond. We believe that computed tomography reports should highlight this anatomical finding to alert the clinical team monitoring the patient.