Acute Type B Intramural Hematoma: Novel Insights in the Endovascular Era.

BACKGROUND: The pathophysiology and behavior of acute type B intramural hematoma (TBIMH) is poorly understood. The purpose of this study is to characterize the pathophysiology, fate, and outcomes of TBIMH in the endovascular era. METHODS: A retrospective analysis of a US Aortic Database identified 70 patients with TBIMH from 2008 to 2022. Patients were divided into groups and analyzed based upon subsequent management: early thoracic endovascular aortic repair (TEVAR; Group 1) or hospital discharge on optimal medical therapy (OMT) (Group 2). RESULTS: Of 70 total patients, 43% (30/70) underwent TEVAR (Group 1) and 57% (40/70) were discharged on OMT (Group 2). There were no significant differences in age, demographics, or comorbidities between groups. Indications for TEVAR in Group 1 were as follows: 1) Penetrating atheroscletoic ulcer (PAU) or ulcer-like projection (n = 26); 2) Descending thoracic aortic aneurysm (n = 3); or 3) Progression to type B aortic dissection (TBAD) (n = 2). Operative mortality was zero. No patient suffered a stroke or spinal cord ischemia. During the follow-up period, 50% (20/40) of Group 2 patients required delayed surgical intervention, including TEVAR in 14 patients and open repair in 6 patients. Indications for surgical intervention were as follows: 1) Development of a PAU / ulcer-like projection (n = 13); 2) Progression to TBAD (n = 3), or 3) Concomitant aneurysmal disease (n = 4). Twenty patients did not require surgical intervention. Of the initial cohort, 71% of patients required surgery, 9% progressed to TBAD, and 19% had regression or stability of TBIMH with OMT alone. CONCLUSIONS: The most common etiology of TBIMH is an intimal defect. Progression to TBAD and intramural hematoma regression without an intimal defect occurs in a small percentage of patients. An aggressive strategy with endovascular therapy and close surveillance for TBIMH results in excellent short-term and long-term outcomes.

Acute-on-Chronic Aortic Dissection: Management and Outcomes of the Unstable "Triple-Lumen" Aorta.

BACKGROUND: The impact of acute aortic dissection of the chronically dissected distal aorta is unknown. This study sought to describe the incidence and characteristics of the triple-lumen aortic dissection and its impact on survival. METHODS: From 2010 to 2021, a query of a single-institution aortic database identified 1149 patients with chronic distal aortic dissection. Thirty-three (2.9%) patients with at least 3 distinct lumens and 2 separate "primary" intimal tears were identified by analysis of contrast-enhanced cross-sectional imaging. Triple-lumen patients were exactly matched with a cohort of double-lumen patients on a 1:1 ratio using 5 preoperative variables, and outcomes between the groups were assessed. RESULTS: The median age at time of initial dissection in patients with a triple-lumen dissection was 46 years. Initial dissection was a type A in 33% and a type B in 67% of patients. The median time from initial dissection to triple-lumen diagnosis was 4.2 years. On diagnosis of the triple-lumen aorta, 85% of patients required urgent aortic repair for rapid growth (36%), aortic diameter ≥55 mm (30%), malperfusion (6%), intractable pain (6%), and rupture/type A (6%). Thirty-day mortality after triple lumen dissection was 12%. CONCLUSIONS: Acute-on-chronic distal dissection resulting in a triple-lumen aorta should be classified as a "complicated" type B dissection as these patients typically have large aneurysms and a high incidence of rapid false lumen expansion requiring urgent surgical repair.