Spontaneous non-traumatic rupture of the thoracic aorta

Intimomedial tears of the aorta heal by smooth muscle cell-mediated fibrosis without atherosclerosis

BACKGROUNDDisease of the aorta varies from atherosclerosis to aneurysms, with complications including rupture, dissection, and poorly characterized limited tears. We studied limited tears without any mural hematoma, termed intimomedial tears, to gain insight into aortic vulnerability to excessive wall stresses. Our premise is that minimal injuries in aortas with sufficient medial resilience to prevent tear progression correspond to initial mechanisms leading to complete structural failure in aortas with significantly compromised medial resilience.METHODSIntimomedial tears were macroscopically identified in 9 of 108 ascending aortas after surgery and analyzed by histology and immunofluorescence confocal microscopy.RESULTSNonhemorrhagic, nonatheromatous tears correlated with advanced aneurysmal disease and most lacked distinctive symptoms or radiological signs. Tears traversed the intima and part of the subjacent media, while the resultant defects were partially or completely filled with neointima characterized by differentiated smooth muscle cells, scattered leukocytes, dense fibrosis, and absent elastic laminae despite tropoelastin synthesis. Healed lesions contained organized fibrin at tear edges without evidence of plasma and erythrocyte extravasation or lipid accumulation.CONCLUSIONThese findings suggest a multiphasic model of aortic wall failure in which primary lesions of intimomedial tears either heal if the media is sufficiently resilient or progress as dissection or rupture by medial delamination and tear completion, respectively. Moreover, mural incorporation of thrombus and cellular responses to injury, two historically important concepts in atheroma pathogenesis, contribute to vessel wall repair with adequate conduit function, but even together are not sufficient to induce atherosclerosis.FUNDINGNIH (R01-HL146723, R01-HL168473) and Yale Department of Surgery.

Limited Aortic Intimal Tears: CT Imaging Features and Clinical Characteristics

Limited aortic intimal tear is an uncommon lesion of the dissection spectrum. The lesion has several imaging features that are not well known, including asymmetric aortic contour abnormalities, filling defects, and various morphologic patterns, such as linear, L-shaped, T-shaped, and stellate configurations. Hemorrhage of the aortic wall may also be present in patients with this rare entity. This imaging essay reviews the CT imaging findings and clinical characteristics of patients with limited intimal tears. Keywords: Aorta, CT © RSNA, 2022.

Acute Limited Intimal Tears of the Thoracic Aorta

BACKGROUND

Limited intimal tears (LITs) of the aorta (Class 3 dissection variant) are the least common form of aortic pathology in patients presenting with acute aortic syndrome (AAS). LITs are difficult to detect on imaging and may be underappreciated.

OBJECTIVES

This study sought to describe the frequency, pathology, treatment, and outcome of LITs compared with other AAS, and to demonstrate that LITs can be detected pre-operatively by contemporary imaging.

METHODS

The authors retrospectively reviewed 497 patients admitted for 513 AAS events at a single academic aortic center between 2003 and 2012. AAS were classified into classic dissection (AD), intramural hematoma, LIT, penetrating atherosclerotic ulcer, and rupturing thoracic aortic aneurysm. The prevalence, pertinent risk factors, and detailed imaging findings with surgical and pathological correlation of LITs are described. Management, early outcomes, and late mortality are reported.

RESULTS

Among 497 patients with AAS, the authors identified 24 LITs (4.8% of AAS) in 16 men and 8 women (17 type A, 7 type B). Patients with LITs were older than those with AD, and type A LITs had similarly dilated ascending aortas as type A AD. Three patients presented with rupture. Eleven patients underwent urgent surgical aortic replacement, and 2 patients underwent endovascular repair. Medial degeneration was present in all surgical specimens. In-hospital mortality was 4% (1 of 24), and in total, 5 patients with LIT died subsequently at 1.5 years (interquartile range [IQR]: 0.3 to 2.5 years). Computed tomography imaging detected all but 1 LIT, best visualized on volume-rendered images.

CONCLUSIONS

LITs are rare acute aortic lesions within the dissection spectrum, with similar presentation, complications, and outcomes compared with AD and intramural hematoma. Awareness of this lesion allows pre-operative diagnosis using high-quality computed tomography angiography.

Ascending Aortic Rupture through a Penetrating Atherosclerotic Ulcer: A Rare Cause of Sudden Unexpected Death

Spontaneous rupture of the aorta through an atherosclerotic lesion without preexisting aortic aneurysm, dissection, or history of trauma is very rare. Without prompt aortic repair, all cases result in sudden death with a definitive diagnosis made only intraoperatively or during autopsy. The phenomenon has been uniformly found in individuals with hypertension. The author reports a sudden unexpected death caused by spontaneous rupture of the ascending aorta in a 57-year-old man with a history of hypertension. The ascending aortic wall showed a longitudinal intimal tear measuring approximately 1 cm in length and rupture of the ascending aorta through an atherosclerotic ulcer, leading to massive hemopericardium and eventual death. Chronic hypertension and a penetrating atherosclerotic ulcer of the ascending aorta were the apparent underlying etiologies of the aortic rupture in the present case. This case illustrates not only the association between a rupture and a penetrating atherosclerotic ulcer with a silent death, but also raises awareness of possible such deaths.

Survival following localised aortic atherosclerotic plaque rupture

Spontaneous rupture of the aorta due to ruptured atherosclerotic plaque is extremely rare. Despite the high prevalence of atherosclerosis, only four cases have been reported to have been identified and treated successfully; the remainder were diagnosed postmortem. We report a surviving case of pericardial tamponade due to highly localised aortic atherosclerotic plaque rupture.

Rupture of a small fusiform thoracic aortic aneurysm

We report a case of ruptured aortic aneurysm of the distal aortic arch. This aneurysm was fusiform and only 4.0 cm in maximum diameter. Emergency total aortic arch replacement was successful. Rupture of a thoracic aortic aneurysm of this shape and size is possible but extremely rare.

Spontaneous rupture of the thoracic aorta

BACKGROUND

Spontaneous rupture of the thoracic aorta without trauma, aneurysm, or dissection is an extremely rare but catastrophic disorder. Two cases of spontaneous aortic rupture are presented, both treated surgically with satisfactory results.

METHODS

A review of the English literature found 16 patients with the diagnosis of spontaneous rupture of the thoracic aorta from 1961 through 1998. Eighteen reported cases, including the 2 cases presented herein, are reviewed.

RESULTS

The representative clinical picture is one of a middle-aged hypertensive patient with acute chest pain and collapse, with imaging modalities demonstrating hemopericardium, hemomediastinum, or hemothorax. According to the reported experiences, aortography was accurate for identifying the rupture site although the findings were sometimes subtle. Misdiagnosis or nonsurgical management resulted in the patient's death. All 8 patients who did not undergo aortic repair died within 3 weeks after the onset, whereas 9 of 10 patients who underwent surgical aortic repair survived.

CONCLUSIONS

For patients with a definitive or possible diagnosis of spontaneous rupture of the thoracic aorta, prompt operation is imperative through an optimal surgical approach to identify and repair the rupture site with appropriate circulatory support.

Atypical chest pain

The initial approach to patients with a chief complaint of chest pain is to rule out myocardial ischemia. There are, however, other life-threatening causes of chest pain, including pulmonary emobilism and aortic dissection among many others. This article reviews several of these disease processes.

Spontaneous rupture of non-aneurysmal ascending aorta

Two autopsy cases with pericardial tamponade and spontaneous rupture of non-aneurysmal ascending aorta are described. In case 1, no apparent predisposing factor was clinically noticed in a 74 year old male patient, but postmortem examination revealed laceration of the ascending aorta associated with aortic valvular deformity and slight dilatation of the ascending aorta. In case 2, a 61 year old man, a mild to moderate grade of aortic regurgitation was noticed clinically 5 months before death. Postmortem examination revealed a slight dilatation of the aortic annulus and post-valvular portion of the ascending aorta. These two cases emphasize the clinical significance of aortic valvular disease with subsequent disordered blood flow, even when asymptomatic, as a potential causative factor for spontaneous rupture of the ascending aorta.

A case of spontaneous innominate artery perforation with pericardial tamponade

We describe a case of a spontaneously occurring innominate artery perforation which, rather than resulting in immediate death, developed a subacute course with findings suggestive of an expanding mediastinal mass. The cause of the spontaneous perforation appears to have been a combination of atherosclerosis, infection, and infiltration of the underlying structures with malignancy. This is a unique case of subacute spontaneous perforation of a great vessel.