Figure 1
Figure 1
Interposition of lung tissue between the aorta and the main segment of the pulmonary artery.
Partial Absence of Pericardium
SectionCardiovascular
Case TypeClinical Cases
AuthorsAlzahrani A, Loutfi S
Connected authors
55 years, male
Clinical History
A 55-year-old male presented to the ER with trauma.
Imaging Findings
A 55-year-old patient without history of any medical condition was involved in a motor vehicle accident and presented with right side chest tenderness. CT examination of the chest was performed and showed no acute chest injury. Incidentally an interposition of lung tissue between the aorta and the main segment of the pulmonary artery was found (Figs. 1, 2, 3, 4).
Discussion
The prevalence of congenital absence of the pericardium, including cases with other congenital cardiopulmonary anomalies, has been described as only 0.002–0.044% of surgical/pathologic investigations; therefore, isolated absence of the pericardium is a very rare malformation. [1]
Most pericardial defects are partial and occur on the left side. Infrequently, defects also occur on the right side or at the diaphragmatic surface. [2] The cause of this anomaly is attributed to premature atrophy of the left duct of Cuvier, resulting in a deficiency of blood supply to the left pleuropericardial membrane, which in adult life, forms the left pericardium. The right duct of Cuvier normally persists as the superior vena cava, ensuring adequate blood supply to the developing right pericardium. The ratio of incidence in males and females is 3:1. [3]
Normally, the aortopulmonary window is covered by pericardium and contains some fat. Left-sided absence of the pericardium allows interposition of lung tissue between the aorta and the main segment of the pulmonary artery, and, occasionally, bulging of the left atrial appendage through the defect. As a result of these abnormalities, the heart usually rotates toward the left. Although radiographs may show evidence of this condition, a definitive diagnosis can be obtained with either CT or MR imaging. Patients with pericardial defects also may have one or more associated congenital abnormalities, including atrial septal defect, patent ductus arteriosus, mitral valve stenosis, or tetralogy of Fallot which also are detectable on CT or MR images. [2]
Unless there is an associated cardiac anomaly, the majority of patients are asymptomatic. When symptoms are present, the most common complaint is of non-specific chest pain, probably from the abnormal torsion or strain on the great vessels due to greater mobility of the heart. With partial pericardial defects, there is possibility of herniation of atrial appendage or left ventricle, with the potential for strangulation of the heart. Surgical repair is therefore generally recommended when a partial pericardial defect is diagnosed. Complete left sided absence of pericardium is apparently without any lethal potential and does not require surgical intervention unless rare complications such as tricuspid valve insufficiency develop. [3]
Most pericardial defects are partial and occur on the left side. Infrequently, defects also occur on the right side or at the diaphragmatic surface. [2] The cause of this anomaly is attributed to premature atrophy of the left duct of Cuvier, resulting in a deficiency of blood supply to the left pleuropericardial membrane, which in adult life, forms the left pericardium. The right duct of Cuvier normally persists as the superior vena cava, ensuring adequate blood supply to the developing right pericardium. The ratio of incidence in males and females is 3:1. [3]
Normally, the aortopulmonary window is covered by pericardium and contains some fat. Left-sided absence of the pericardium allows interposition of lung tissue between the aorta and the main segment of the pulmonary artery, and, occasionally, bulging of the left atrial appendage through the defect. As a result of these abnormalities, the heart usually rotates toward the left. Although radiographs may show evidence of this condition, a definitive diagnosis can be obtained with either CT or MR imaging. Patients with pericardial defects also may have one or more associated congenital abnormalities, including atrial septal defect, patent ductus arteriosus, mitral valve stenosis, or tetralogy of Fallot which also are detectable on CT or MR images. [2]
Unless there is an associated cardiac anomaly, the majority of patients are asymptomatic. When symptoms are present, the most common complaint is of non-specific chest pain, probably from the abnormal torsion or strain on the great vessels due to greater mobility of the heart. With partial pericardial defects, there is possibility of herniation of atrial appendage or left ventricle, with the potential for strangulation of the heart. Surgical repair is therefore generally recommended when a partial pericardial defect is diagnosed. Complete left sided absence of pericardium is apparently without any lethal potential and does not require surgical intervention unless rare complications such as tricuspid valve insufficiency develop. [3]
Differential Diagnosis List
Partial absence of the pericardium.
Final Diagnosis
Partial absence of the pericardium.
References
[1] Tetsuhiro Y, Takahisa S, Kenzo S, Takeshi N, Akihiro A, Masao N (2004) Magnetic Resonance Imaging Differentiated Partial From Complete Absence of the Left Pericardium in a Case of Leftward Displacement of the Heart. Circ J 68:385 388. (PMID: 15056840)
[2] Wang ZJ, Reddy GP, Gotway MB, Yeh BM, Hetts SW, Higgins CB (2003) CT and MR Imaging of Pericardial Disease.October 2003 RadioGraphics 23:S167-S180. (PMID: 14557510)
[3] Tee HM, Carty AT (2003) Case of the month: a heart problem? Br J Radiol 76:211212. (PMID: 12684238)
Case information
| URL: | https://www.eurorad.org/case/8115 |
| DOI: | 10.1594/EURORAD/CASE.8115 |
| ISSN: | 1563-4086 |
Figure 1
Interposition of lung tissue between the aorta and the main segment of the pulmonary artery.
Figure 2
Interposition of lung tissue between the aorta and the main segment of the pulmonary artery.
