Learning objectives
Hemorrhagic infiltration of the pulmonary artery connective sheath is a rare complication that may result in a case of acute aortic dissection,
most frequently,
Stanford type A (1,
2).
The radiological interpretation of this finding may be of a diagnostic challenge.
Multidetector computed tomography (MDCT) is the modality of choice for the diagnosis of this entity.
MDCT can also be used to monitor the evolution of this life threatening disease.
It is of great importance that radiologists can recognize and properly diagnose this complication,
since...
Background
Anatomically,
pulmonary arteries and bronchi along with the lymphatic channels are closely surrounded by a sheath of connective tissue.
This sheath is connected to the mediastinum (3).
In aortic dissection,
especially Stanford type A,
this sheath loses its firm tightness,
resulting in the formation of a hemomediastinum (3).
At this point,
this condition can lead to many complications.
Frequently,
hemorrhagic extravasations into an extrapleural route can create a 'apical cap'.
Also,
the pressure exerted by the hemomediastinum can fissure the pleura and form a hemothorax...
Imaging findings OR Procedure details
Materials and Methods
Literature review:
A literature review using PUBMED ('aortic dissection' infiltration of the lung parenchyma ',' interstitial pulmonary hemorrhage ') has led to the identification of seven reported cases,
illustrated by computed tomography (1,
2,
5,
6,
7,
8,
and 9).
Our radiological cases:
Case series of twelve aortic dissections with hemorrhagic infiltration of the aortopulmonary sheath,
from five academic centers was reported from 2008 to 2010.
The medical records were reviewed.
Computed tomography (MDCT) was performed for each patient.
Our pathological cases:...
Conclusion
Proposed mechanism
The suggested mechanism to explain this entity involves dissection with contained rupture of the ascending aorta and the formation of a hemorrhagic infiltration limited to the extravasation of aortic blood along the aortopulmonary connective sheath (usually a virtual space in a normal patient),
with consequent compression of the pulmonary arteries.
This vascular compression would result in distal edema with hemorrhage of the lung parenchyma.
Conclusion
Hemorrhagic infiltration of the common aortopulmonary connective in acute aortic dissection,
primarily Stanford type A,
is a rare...
References
1.
Panicek DM,
Ewing DK,
Markarian B,
Heitzman ER.
Interstitial pulmonary hemorrhage from mediastinal hematoma secondary to aortic rupture.
Radiology.
1987 Jan;162(1 Pt 1):165-6.
2.
Cao DB,
Yang SR,
Tong Q,
Zheng Y.
Interstitial pulmonary hemorrhage along the pulmonary artery secondary to ruptured aortic dissection.
Intern Med.
2010;49(15):1681-2.
Epub 2010 Aug 2.
3.
MARCHAND P.
The anatomy and applied anatomy of the mediastinal fascia.
Thorax.
1951 Dec;6(4):359-68
4.
Ramanath VS,
Oh JK,
Sundt TM 3rd,
Eagle KA.
Acute aortic syndromes and thoracic aortic aneurysm.
Mayo...