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.

Long-Term Results of Valve Sparing Aortic Root Replacement in Acute Type A Aortic Dissection.

BACKGROUND: Valve preservation in acute type A aortic dissection (ATAAD) can be accomplished with root repair or replacement. Long-term valve durability with root repair has been established, but limited data exists regarding long-term durability of valve sparing root replacement (VSRR). This study compared long-term results of VSRR to root repair in ATAAD. METHODS: From 2005-2023, 866 patients underwent ATAAD repair, of which 675 underwent root repair and 191 underwent root replacement (VSRR = 65, Bentall = 126). VSRR patients were compared to 123 patients who underwent valve resuspension and root repair (Root Repair) with postoperative echocardiograms ≥ 1 year. RESULTS: VSRR patients were younger (VSRR 44±11 vs. Root Repair 55±13 years, p<0.001). Preoperatively, 57% of VSRR and 35% of Root Repair patients had ≥ moderate aortic insufficiency. Cardiopulmonary bypass and, myocardial ischemia times were significantly longer in VSRR (p<0.001). Postoperative echocardiograms with ≥ 1 year follow-up were analyzed in 58 VSRR patients with median follow-up of 4.8 [IQR 3,12] years and in 123 Root Repair patients with median follow-up of 3.6 [IQR 3, 8] years. At 10 years, VSRR patients had superior freedom from > mild aortic insufficiency (VSRR 91% vs. Root Repair 49%, p <0.001). At 10 years, freedom from aortic valve replacement was equivalent (VSRR 98% vs. Root Repair 92%, p=0.269). CONCLUSIONS: VSRR provides equivalent long-term valve durability as root repair in ATAAD, even in patients with moderate or severe aortic insufficiency. In select young patients who require root replacement during ATAAD repair, VSRR represents an ideal therapy.

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.