Hemorrhagic infiltration of the aortopulmonary adventitia: A complication of acute aortic dissection

Impact of pulmonary artery intramural hematoma on patients with acute type A aortic dissection

OBJECTIVES

To investigate the short-term/long-term impact of pulmonary artery intramural hematoma (PA-IMH) in patients with acute Stanford type A aortic dissection (ATAAD) following surgical repair.

MATERIALS AND METHODS

Consecutive patients with ATAAD who received surgical repair at Beijing and Yunnan Fuwai Hospital in 2010-2021 were retrospectively reviewed. Patients with hemorrhage extending along the PA were identified as the PA-IMH group. Multivariable logistics regression was used to obtain the odds ratio (OR), and the Kaplan-Meier method was used to estimate the survival rate.

RESULTS

Of the 2046 ATAAD patients, 324 (15.8%) patients were identified with PA-IMH, and 1722 (84.2%) were without PA-IMH. PA-IMH had a higher prevalence in patients with older age, female gender, aortic IMH, and type II aortic dissection. PA-IMH patients incurred excess early mortality compared with non-PA-IMH patients (9.3% vs. 5.6%, OR = 1.86, 95%CI 1.19-2.91, p = 0.006). The results were stable in the subgroup analysis, with an increased risk in older (> 70 years) or DeBakey type II ATAAD patients. Notably, an increase in the degree and extent of PA-IMH exacerbated the risk of early mortality. However, after landmark analysis at 30-day postsurgery, no significant difference was noted in the long-term outcomes between PA-IMH and non-PA-IMH groups (p = 0.440). The 5-year survival rates were 87.1% (95%CI: 83.3%, 91.1%) and 90.1% (95%CI: 88.5%, 91.7%), respectively.

CONCLUSIONS

The presence of PA-IMH in ATAAD patients is common and is independently associated with increased early mortality after surgical repair, especially in those with older age (> 70) or type II dissection. However, such detrimental effects do not persist in the long-term follow-up among patients who survived hospital discharge.

CLINICAL RELEVANCE STATEMENT

We confirmed that PA-IMH significantly increases early postoperative mortality in patients with acute type A aortic dissection, especially in older patients or DeBakey type II dissection. This should prompt further investigation of the incremental role of PA-IMH in this pathology.

KEY POINTS

Acute type A aortic dissection mortality gets worse when pulmonary artery intramural hematoma is present. Pulmonary artery-intramural hematoma increased the risk of early mortality but not affect long-term prognosis. Further research should investigate the effects of pulmonary artery intramural thrombus on aortic dissection.

Acute aortic dissection complicated with hemorrhagic aortopulmonary artery sheath: a review of the literature

A hemorrhagic aortopulmonary artery sheath (HAPS) is an infrequent and critical complication of aortic dissection (AD), which is caused by a hematoma extending through the ruptured aortic wall into the aortopulmonary artery sheath. The adventitial hematoma might narrow or even occlude the lumen of the pulmonary arteries and extend into the pulmonary interstitium and alveoli. The prompt and accurate recognition of HAPS on computed tomography (CT) is crucial and might assist in the diagnosis of unidentifiable AD. HAPS was manifested as high attenuation areas surrounded the pulmonary arteries without enhancement on CT; even thickened bronchovascular sheath and ground-glass consolidations surrounded bronchovascular distribution, which might be associated with the prognosis. Aggressive and effective surgical treatment is the primary determinant of short-term survival.

MDCT Imaging of Non-Traumatic Thoracic Aortic Emergencies and Its Impact on Diagnosis and Management—A Reappraisal

Non-traumatic thoracic aorta emergencies are associated with significant morbidity and mortality. Diseases of the intimomedial layers (aortic dissection and variants) have been grouped under the common term of acute aortic syndrome because they are life-threatening conditions clinically indistinguishable on presentation. Patients with aortic dissection may present with a wide variety of symptoms secondary to the pattern of dissection and end organ malperfusion. Other conditions may be seen in patients with acute symptoms, including ruptured and unstable thoracic aortic aneurysm, iatrogenic or infective pseudoaneurysms, aortic fistula, acute aortic thrombus/occlusive disease, and vasculitis. Imaging plays a pivotal role in the patient’s management and care. In the emergency room, chest X-ray is the initial imaging test offering a screening evaluation for alternative common differential diagnoses and a preliminary assessment of the mediastinal dimensions. State-of-the-art multidetector computed tomography angiography (CTA) provides a widely available, rapid, replicable, noninvasive diagnostic imaging with sensitivity approaching 100%. It is an impressive tool in decision-making process with a deep impact on treatment including endovascular or open surgical or conservative treatment. Radiologists must be familiar with the spectrum of these entities to help triage patients appropriately and efficiently. Understanding the imaging findings and proper measurement techniques allow the radiologist to suggest the most appropriate next management step.

CT of the Difficult Acute Aortic Syndrome

Acute aortic syndrome (AAS) is classically attributed to three underlying pathologic conditions-aortic dissection (AD), intramural hematoma (IMH), and penetrating atherosclerotic ulcer (PAU). In the majority of cases, the basics of image interpretation are not difficult and have been extensively reviewed in the literature. In this article, the authors extend existing imaging overviews of AAS by highlighting additional factors related to the diagnosis, classification, and characterization of difficult AAS cases. It has been well documented that AAS is caused not only by an AD but by a spectrum of lesions that often have overlap in imaging features and are not clearly distinguishable. Specifically, phase of contrast enhancement, flow artifacts, and flapless AD equivalents can complicate diagnosis and are discussed. While the A/B dichotomy of the Stanford system is still used, the authors subsequently emphasize the Society for Vascular Surgery's new guidelines for the description of acute aortic pathologic conditions given the expanded use of endovascular techniques used in aortic repair. In the final section, atypical aortic rupture and pitfalls are described. As examples of pericardial and shared sheath rupture become more prevalent in the literature, it is important to recognize contrast material third-spacing and mediastinal blood as potential mimics. By understanding these factors related to difficult cases of AAS, the diagnostic radiologist will be able to accurately refine CT interpretation and thus provide information that is best suited to directing management. Online supplemental material is available for this article. ^©RSNA, 2021.

Case Series: Pulmonary Artery Intramural Hematoma in Stanford Type A Acute Aortic Dissection

Main Teaching Point: Diagnosing acute ascending aortic dissection in patients with equivocal radiologic data may rely on associated findings such as pulmonary artery intramural hematoma.

The immediate diagnosis of aortic dissection is paramount in its management. Its diagnosis may be challenging on computed tomography when the intimal flap, pathognomonic of dissection, is not readily visualized. Pulmonary artery intramural hematoma may arise from rupture of the posterior wall of the ascending aorta into the common aortopulmonary adventitia as a result of acute dissection. The clinical significance of pulmonary artery hematoma is unknown, but its presence may facilitate the diagnosis of acute dissection when other radiologic findings are equivocal. Herein, we present four cases of pulmonary artery intramural hematoma associated with Stanford type A acute aortic dissection, among whom patient outcomes depended mainly on the prompt treatment the dissection.

Computed Tomography Angiography Assessment of Acute Aortic Syndromes: Classification, Differentiating Imaging Features, and Imaging Interpretation Pitfalls

An acute aortic syndrome (AAS) is an important life-threatening condition that requires early detection and management. Acute intramural hematoma (IMH), aortic dissection (AD) and penetrating atherosclerotic ulcer (PAU) are included in AAS. ADs can be classified using the well-known Stanford or DeBakey classification systems. However, these classification systems omit description of arch dissections, anatomic variants, and morphologic features that impact outcome. The Society for Vascular Surgery and Society of Thoracic Surgeons (SVS-STS) have recently introduced a classification system that classifies ADs according to the location of the entry tear (primary intimomedial tear, PIT) and the proximal and distal extent of involvement, but does not include description of all morphologic features that may have diagnostic and prognostic significance. This review describes these classification systems for ADs and other AAS entities as well as their limitations. Typical computed tomography angiography (CTA) imaging appearance and differentiating features of ADs, limited intimal tears (LITs), IMHs, intramural blood pools (IBPs), ulcer-like projections (ULPs), and PAUs will be discussed. Furthermore, this review highlights common imaging interpretation pitfalls, what should be included in a comprehensive CTA report, and provides a brief overview of current management options.

Pulmonary artery compression by hematoma, a rare but life-threatening complication of Stanford type A aortic dissection

Hemorrhagic extension along the pulmonary arteries should be recognized as a complication of Stanford type A aortic dissection. Radiologists and other physicians with an interest in cardiothoracic imaging should be aware of this rare but life-threatening pathology. The anatomical concept of the pathology is outlined in this text, through high-quality electrocardiogram-gated computerized tomography images.

Non-contrast computed tomography of type A acute aortic dissection in patients with out-of-hospital cardiopulmonary arrest: a case series

Background

The prognosis of patients admitted for acute aortic dissection (AAD) has remarkably improved. However, we must also consider out-of-hospital cardiopulmonary arrest (OHCPA) patients while assessing the prognosis. In recent years, autopsy imaging has become more common as an alternative to conventional autopsy. Therefore, we reviewed our OHCPA patients with type A AAD using acute phase non-contrast computed tomography (CT).

Case summary

Here, we report a case series of three patients who developed OHCPA and were diagnosed with type A AAD using non-contrast CT. Although the direct causes of death varied in each case, we could easily determine the direct causes of death from clinical course of the condition and from non-contrast CT.

Discussion

Although non-contrast CT does not completely replace autopsy, if its convenience and non-invasiveness make it possible for more patients to undergo the procedure, the real prognosis (including morbidity and mortality) may be better understood. Therefore, we considered it significant to use non-contrast CT for investigating the cause of sudden death.

Imaging of Pulmonary Embolus: Thrombotic, Nonthrombotic, and Mimickers

Pulmonary embolism is a common and potentially fatal pathological condition. Imaging plays a crucial role in the diagnosis and differentiation of the causes of pulmonary embolus. Here we present typical imaging findings associated with both thrombotic and nonthrombotic pulmonary emboli, as well as their potential mimickers.

VIDEO: Rethinking "Mural Thickening:" Vasculitis or Aortic Dissection?

OBJECTIVE

The objective of this video article is to provide education about the similarities and differences between vasculitis and rare, acute aortic pathologic findings so that an appropriate diagnosis can be made in a timely manner, especially for patients with life-threatening aortic pathologic findings.

CONCLUSION

Although they are rare, acute aortic pathologic findings, such as aortic dissection and intramural hematoma, can have radiographic characteristics similar to those of vasculitis, which can make it challenging to discern between these vastly different diagnoses without the use of properly timed imaging studies.