PC024. Lower Limb Malperfusion in Acute Type A Dissection

Objective: Acute type A aortic dissection (ATAD)presenting with acute limb ischemia (ALI)has been identified as a predictor of in-hospital mortality. This study examines the outcome of patients presenting with ATAD with ALI. Methods: A prospectively collected database was queried for all cases of ATAD repaired between 2002 and 2018 at a tertiary referral center. Patients presenting with ALI were identified. Comparisons between groups with and without lower extremity ALI were made. For continuous variables, univariate two-group comparisons were performed. For categorical variables, univariate two-group comparisons are performed. Statistical significance is set at P \u3c.05. Results: During this period, 378 patients (average age, 56.9 years)underwent ATAD repair. Of these, 62 patients (16.4%)presented with ALI; 35 patients (9.2%)presented with isolated ALI, whereas 27 (7.1%)had concomitant malperfusion in at least one other organ system. Of the 62 patients presenting with ALI, 46 (74.2%)underwent proximal aortic repair alone; 16 (25.8%)also underwent lower extremity vascular intervention (Fig). In the latter part of the study, perfusion of the ischemic limb was accomplished during repair of the ATAD through a side perfusion cannula directly from the bypass circuit (10 patients). There were six amputations (9.7%)performed in the ALI group, two of which had peripheral vascular repairs. Fasciotomies were performed on 18 patients; of these, 5 had concomitant peripheral vascular repairs. Of the 55 patients with ALI surviving past 24 hours, 34 (61%)had resolution of their lower limb ischemia with proximal repair only. The 30-day survival was decreased in patients who presented with any organ malperfusion (P =.012). However, in patients with isolated ALI, there was no significant difference in 30-day mortality (11.4%)compared with the group with no malperfusion (15.7%; P =.5). Sixteen patients underwent peripheral vascular procedures for their limb ischemia, including 10 patients who underwent bypass procedures (7 femoral-femoral, 1 axillary-femoral-femoral, and 2 axillary-femoral), with 1 patient dying within 24 hours. All six patients with adequate follow-up imaging demonstrated asymptomatic occlusion of the bypass graft. In this group, computed tomography angiography showed recanalization of the occluded native arteries. Conclusions: Proximal repair of ATAD resolves most associated ALI. Isolated ALI did not increase 30-day mortality. All patients with follow-up who underwent extra-anatomic bypass developed asymptomatic graft occlusion. This was attributed to competitive flow from the remodeled native arterial system. [Figure presented