The Results and Rationale of Tevar Procedure for Type B Intramural Hematoma of Aorta

Abstract

Introduction: Aortic intramural hematoma (IMH) is one of the major acute aortic syndromes with potential lethal complications. The one involving aorta distal to innominate artery is referred to Type B IMH (BIMH) and is now mainly treated medically under careful surveillance and repetitive computing tomography (CT) follow-up[1]. For complicated IMH, it means relapsed chest pain, periaortic hemorrhage, presence of intimal disruption, or enlarging IMH, and is recommended to undergo invasive intervention [1][2]. We aim to analyze the effectiveness and outcome of thoracic endovascular aortic repair (TEVAR) as primary management of BIMH patients with variable indications in our hospital and attempt to establish rationale accordingly. Methods: From January 2015 to July 2018, 41 complicated BIMH patients treated with TEVAR were retrospectively reviewed. Initial CT images focusing on aorta diameter, IMH thickness, and intimal disruption along with surgeons' and peer reviewer's indication were presented. Procedure details, postoperative results including mortality, complication, and re-intervention events, the remodeling of aorta, and occurrence of new ulcer like projection (ULP) or intramural blood pool (IBP) during follow-up were recorded as outcome. Results: Among 41 patients, one had aorta maximal diameter >55mm, 87.8% had IMH thickness >1cm, 17.1% had intimal disruption depth >1cm, and only 7.3% met indication for classic penetrating aortic ulcer (PAU) standard (>2cm width and >1cm depth), whereas surgeons' recorded 58.5% of IMH with PAU as operative indication. IBP could be found in 51.2% patients [Table1]. There was one technique failure due to critical aorto-iliac occlusive disease. Mean 2.1 aortic stents were deployed, most were proximal Zone 3 and distal T9th landing; furthermore, 8 Chimneys, 2 coil emboli and 1 ex vivo fenestration to left subclavian artery were applied. Patients were discharged on post-op day 2-95 (mean 8.3). Nine patients were lost to follow-up. There was 0 early-mortality and 7 all cause late-mortality (17.1%). One was aorta-related. Early complications rate was 26.8%, including iliac occlusion, brain emboli, progressive paraplegia, pneumonia etc. Late complications rate was 31.7%, including proximal/distal stent-induced new entries, new ULPs and abdominal aortic aneurysm rupture etc. Re-intervention rate was 7.5%, mostly procedure-related (4/6). 84.4% had healing of target segment. 53.1% had complete thrombosis of native aorta. Up to 37.5% follow-up patients developed new ULPs or IBPs [Fig1]. Conclusion: The diagnosis of PAU is not standardized, for a large portion of patients with small and shallow ULPs/IBPs or tiny intimal disruption (TID) were treated as IMH with PAU. As for the procedure itself, TEVAR towards complicated BIMH is effective in eradicating initial intimal tears and preventing aortic related death but carries relatively high procedure-related complications. Besides, high incidence of new ULPs/IBPs in other aortic segments with uncertain causation makes the initial intention questionable.Table 1ULP/TID/IBP lesions in type B IMHFigure 1New ULPs/IBPs development after TEVARView Large Image Figure ViewerDownload Hi-res image Download (PPT) Disclosure: Nothing to disclose