Intramural hematoma of the aorta: diagnosis and treatment

Differential clinical features and long-term prognosis of acute aortic syndrome according to disease entity

AIMS

To evaluate the acute and long-term prognosis of acute aortic syndrome (AAS) according to the disease entity [intramural haematoma (IMH) vs. aortic dissection (AD)] and the anatomical location (type A vs. B).

METHODS AND RESULTS

A total of 1012 patients [672 with AD and 340 with IMH (33.6%)] were enrolled between 1993 and 2015. Compared with AD patients, IMH patients were older and had higher frequency of female sex and distal aorta involvement. The overall crude in-hospital mortality of AAS was 8.6%; type A AD [15.0%; adjusted hazard ratio (aHR) 30.4; 95% confidence interval (CI) 8.62-107.3; P < 0.001], type A IMH (8.0%; aHR 4.85; 95% CI 1.29-18.2; P = 0.019), type B AD (5.0%; aHR 3.51; 95% CI 1.00-12.4; P = 0.051), and type B IMH [1.5%; aHR 1.00 (reference)]. During a median follow-up duration of 8.5 years (interquartile range: 4.0-13.5 years), AD (aHR 2.78; 95% CI 1.87-4.14; P < 0.001) and type A (aHR 2.28; 95% CI 1.45-3.58; P < 0.001) was associated with a higher risk of aortic death. After 90 days, a risk of aortic death was no longer associated with anatomical location (aHR 0.74; 95% CI 0.40-1.36; P = 0.33), but remained associated with disease entity (aHR 1.83; 95% CI 1.10-3.04; P = 0.02).

CONCLUSION

The clinical features, response to treatment strategy, and outcomes of IMH patients were distinct from those of AD patients. Both early and late survival was better for IMH than for AD. In addition to the anatomical location of AAS, the disease entity is an independent factor associated with both acute and long-term mortality in patients with AAS. Further investigation is necessary to confirm the prognostic implication of disease entity in different patient populations.

International Heterogeneity in Diagnostic Frequency and Clinical Outcomes of Ascending Aortic Intramural Hematoma

BACKGROUND

Differing diagnostic frequencies and management strategies for intramural hematoma (IMH) have been described in North American (NA)/European and Japanese/Korean studies.

METHODS

All publications including type-A aortic IMH were reviewed for details on patient demographics, treatment strategy, and clinical outcomes. Publications were stratified by the geographic region (NA/Europe or Japan/Korea).

RESULTS

IMH, as a percentage of aortic dissection, occurs more frequently in Japan/Korea versus NA/Europe (31.7% vs 10.9%, P < .0001). The proportion of patients treated with early medical therapy is greater in Japanese/Korean studies (77.9% vs 48.8% in NA/Europe, P < .0001). However, the overall mortality is significantly lower in Japan/Korea compared with NA/Europe (9.4% vs 20.6%, odds ratio = 2.80, P = .003) in part because of the lower mortality with early medical therapy (7.8% vs 33.3%, P < .0001).

CONCLUSION

There is significant international heterogeneity in the diagnosis and clinical outcomes of ascending IMH. IMH is diagnosed more frequently and has better overall outcomes in Japan/Korea.

Factors associated with in-hospital mortality in patients with acute aortic syndrome involving the ascending aorta

BACKGROUND

Aortic intramural hematoma (IMH), a variant form of classic dissection (AD), is an increasingly recognized and potentially fatal entity of acute aortic syndrome (AAS). We sought to assess the real impact of increased recognition of IMH on mortality of AAS involving the ascending aorta.

METHODS

We evaluated 186 consecutive patients with AAS involving the ascending aorta (57.0+/-13.5 years, 95 females) admitted between January 1993 and March 2003.

RESULTS

Final diagnosis was AD in 135 patients and IMH in 51 (27%). Patients with AD were younger (54.0+/-13 vs. 65.6+/-10.7 years, p<0.05) and surgery was more frequently performed (82% vs. 31%, p<0.001). Overall in-hospital mortality was 16% (30/186); both total mortality (19% vs. 8%, p=0.059) and mortality without surgery (71% vs. 9%, p<0.001) was higher in AD. Logistic regression identified the following presenting variables as predictors of mortality: AD (OR 53.0; 95% CI, 6.6-425.4; p<0.001), confusion/coma (OR 20.1; 95% CI, 3.8-107.8; p<0.001), tamponade (OR 5.3; 95% CI, 1.2-24.3; p=0.031), heart failure (OR 8.1; 95% CI, 1.1-61.0; p=0.043), and medical treatment only (OR 17.6; 95% CI, 4.6-67.6, p<0.001). Tamponade was more prevalent in IMH (25% vs. 11%, p=0.038), and was a predictor of higher mortality in both groups.

CONCLUSION

IMH comprises of significant proportion of AAS involving the ascending aorta and is an independent variable associated with lower mortality despite lower frequency of surgery. Treatment option including optimal timing of surgery can be individualized based on underlying disease entity of AAS and some clinical features at the initial presentation.

Pathologic Characteristics and Surgical Indications of Superacute Type A Intramural Hematoma

BACKGROUND

The treatment policy for acute intramural hematoma involving the ascending aorta remains controversial.

METHODS

This study compared the pathologic characteristics of intramural hematoma with those of acute aortic dissection with a false lumen. The study group comprised 69 patients with intramural hematoma and 156 with acute aortic dissection who underwent emergency operation between 1995 and 2003.

RESULTS

Patients were significantly older in the intramural hematoma group than in the dissection group (67.7 +/- 7.2 years compared with 59.8 +/- 11.6 years; p < 0.0001). Pericardial hemorrhage was present in a higher proportion of patients in the intramural hematoma group than in the dissection group (66.7% compared with 50.6%; p = 0.0257). Three patients (4.3%) died in the intramural hematoma group, whereas 26 patients (16.7%) died in the dissection group (p = 0.011). Histopathologic examination showed no difference in the severity of medial changes, but the site of dissection differed. The thickness of the residual media of the adventitia side was 0.21 +/- 0.12 mm in the intramural hematoma group compared with 0.32 +/- 0.22 mm in the acute aortic dissection group. Dissection was significantly nearer the adventitia in the intramural hematoma group (p = 0.0016).

CONCLUSIONS

Dissection is nearer the adventitia in intramural hematoma than in dissection, leading to a greater probability of rupture. These results suggest that operation as soon as possible after the onset of intramural hematoma will contribute to improved survival.