Familial dissecting aortic aneurysm. A report of three cases within two generations

Murmurs other than the early diastolic murmur in aortic dissection

The purpose of this review is to draw attention to the presence and significance of murmurs other than the murmur of aortic regurgitation, in patients with aortic dissection. For that purpose, a literature search was conducted using Pubmed and Googlescholar. The search terms were "dissecting aneurysm of the aorta", "systolic murmurs", "ejection systolic murmurs", "holosystolic" murmurs, "continuous murmurs", and "Austin-Flint" murmur. Murmurs other than the murmur of aortic regurgitation, which were associated with aortic dissection, fell into the categories of systolic murmurs, some of which were holosystolic, and continuous murmurs, the latter attributable to fistulae between the dissecting aneurysm and the left atrium, right atrium, and the pulmonary artery, respectively. Mid-diastolic murmurs were also identified, and these typically occurred in association with both the systolic and the early diastolic murmurs. Among patients with systolic murmurs clinical features which enhanced the pre-test probability of aortic dissection included back pain, stroke, paraplegia, unilateral absence of pulses, interarm differences in blood pressure, hypertension, shock, bicuspid aortic valve, aortic coarctation, Turner's syndrome, and high D-dimer levels, respectively. In the absence of the murmur of aortic regurgitation timely diagnosis of aortic dissection could be expedited by increased attention to parameters which enhance pretest probability of aortic dissection. That logic would apply even if the only murmurs which were elicited were systolic murmurs.

Do Familial Aortic Dissections Tend to Occur at the Same Age?

BACKGROUND

Prediction of the age at aortic dissection for family members of aortic dissection patients would enhance early detection and clinical management. We sought to determine whether these dissections tend to cluster by age in family members of the dissection patients.

METHODS

Ages at dissection were examined, including 51 sporadic dissectors (one dissection in family) and 39 familial dissectors (two or more dissections in family) from 16 families. Differences between sporadic and familial dissectors and relationships between ages at dissection in family members were analyzed by linear regression and clustering analysis.

RESULTS

Age at dissection was significantly younger in familial versus sporadic dissectors (54.1 ± 15.2 years versus 63.1±12.4 years, p = 0.002). Regression analysis of pairs of family member ages at dissection found a moderately close linear fit (R² = 0.35). Cluster analysis indicated that age at onset of family dissectors increases as age of proband dissector increases. More than 50% of familial dissections occurred within 10 years of the median onset age for any given age decade. For familial dissectors with onset age of 30 to 49 years, 71% of other family member dissections also occurred at age 30 to 49 years, and no dissections occurred above the age of 63 years. For familial dissectors with onset age of 60 to 79 years, 80% of other family member dissections occurred beyond the age of 50 years.

CONCLUSIONS

Familial dissections occur earlier than sporadic dissections. Dissections cluster by age in families, and age at onset can predict the age of other dissectors. This finding argues for consideration of prophylactic resection of an aneurysm in family members approaching the age at onset of prior thoracic aortic dissection.

Novel genetic mechanisms for aortic aneurysms

Aortic aneurysms occur in the thoracic and abdominal sections of the aorta and are a deadly late-age-at-onset disease with complex pathobiology. Currently, the number of published genome-wide analyses including microarray-based expression profiling, DNA linkage studies, and genetic association studies is still limited and it is difficult to make generalizations about the disease pathogenesis or genetic risk factors contributing to aortic aneurysms, but it appears that thoracic aortic aneurysms differ in many ways from abdominal aortic aneurysms. Characterization of diseases at the molecular level is likely to lead to more accurate diagnoses and the use of "genomic nosology" of disease. The biggest future challenge will be to translate the genomic information to the clinic and improve our understanding of the disease processes, help us to develop better diagnostic tools, and lead to the design of new ways to manage aortic aneurysms in the era of personalized medicine.

Acute aortic syndromes and thoracic aortic aneurysm

Acute and chronic aortic diseases have been diagnosed and studied by physicians for centuries. Both the diagnosis and treatment of aortic diseases have been steadily improving over time, largely because of increased physician awareness and improvements in diagnostic modalities. This comprehensive review discusses the pathophysiology and risk factors, classification schemes, epidemiology, clinical presentations, diagnostic modalities, management options, and outcomes of various aortic conditions, including acute aortic dissection (and its variants intramural hematoma and penetrating aortic ulcers) and thoracic aortic aneurysms. Literature searches of the PubMed database were conducted using the following keywords: aortic dissection, intramural hematoma, aortic ulcer, and thoracic aortic aneurysm. Retrospective and prospective studies performed within the past 20 years were included in the review; however, most data are from the past 15 years.

Natural history, pathogenesis, and etiology of thoracic aortic aneurysms and dissections

The natural history of thoracic aortic aneurysms and dissections is diverse, reflecting a broad spectrum of etiologies which include increasing aortic size, hypertension, and genetic factors. The pathogenesis is related to defects or degeneration in structural integrity of the adventitia, not the media, which is required for aneurysm formation. The ascending and descending aorta appear to have separate underlying disease processor that lead to a weakened vessel wall and an increased susceptibility for dissection. Etiologic factors for aortic aneurysms and dissections are multifactorial, reflecting genetic, environmental, and physiologic influences.

Medical treatment of the aorta. I

Diseases of the thoracic aorta are serious conditions that require close observations. Impressive advances in imaging modalities such as magnetic resonance imaging, computed tomography sacs, and transesophageal echocardiography have aided diagnosis and provided insights into the pathogenesis and natural history of thoracic aortic aneurysms, dissection, and atherosclerosis. The current review highlights the etiology, epidemiology, and pathophysiology of these disorders and focuses on the diagnostic approach and suggested medical therapies in the current era.

Reduced penetrance and variable expressivity of familial thoracic aortic aneurysms/dissections

Autosomal dominant inheritance of thoracic aortic aneurysms and dissections occurs in subjects with Marfan syndrome, which results from mutations in the FBN1 gene on chromosome 15. A second chromosomal locus on 3p24-25 has been identified for a Marfan-like condition with thoracic aortic aneurysms. We describe here 6 families with multiple members with thoracic aortic aneurysms and dissections in the absence of the ocular and skeletal complications of Marfan syndrome. Medical records and autopsy reports on affected subjects in families with multiple members with thoracic aortic aneurysms and dissections were reviewed. Subjects in these families at risk for developing aortic disease underwent echocardiography to evaluate the aorta. The pattern of inheritance of thoracic aortic aneurysms and dissections was autosomal dominant in these families. Most affected subjects presented with aortic root dilatation or acute type I dissection, but the age of onset of disease was variable and there was decreased penetrance of the disorder. In 2 of the families, the syndrome was not linked to FBN1 or 3p24-25. Familial thoracic aortic aneurysm and dissection is an autosomal dominant condition with marked variability in the age of onset of aortic disease and decreased penetrance, making identification of affected subjects difficult. This condition is not due to mutations in the FBN1 gene or the unidentified gene on 3p24-25.

Acute thoracic aortic dissection: the basics

With an increasing incidence, aortic dissection is the most common acute illness of the aorta. In the setting of chronic hypertension, with or without other risk factors for aortic dissection, this diagnosis should be considered a diagnostic possibility in patients presenting to the emergency department with acute chest or back pain. Left untreated, about 75% of patients with dissections involving the ascending aorta die within 2 weeks of an acute episode. But with successful initial therapy, the 5-year survival rate increases to 75%. Hence, timely recognition of this disease entity coupled with urgent and appropriate management is the key to a successful outcome in a majority of the patients. This article reviews acute thoracic aortic dissection, including ED diagnosis and management.

Familial aorto-cervicocephalic arterial dissections and congenitally bicuspid aortic valve

BACKGROUND

A primary arteriopathy is often implicated in the etiology of spontaneous cervicocephalic arterial dissections, but its exact nature usually remains unknown. We describe the familial occurrence of spontaneous arterial dissections and congenitally bicuspid aortic valve (BAV) and propose a common developmental defect in these families.

SUMMARY OF REPORT

In the first family, a 63-year-old man suffered an extracranial internal carotid artery (ICA) dissection, and his 43-year-old cousin with BAV suffered an intracranial vertebral artery (VA) dissection. Two other family members had pathologically proven BAV. In the second family, a 31-year-old woman suffered bilateral extracranial ICA and VA dissections. Her father, at age 46, suffered an aortic dissection associated with cystic medial necrosis and BAV. Her paternal uncle died from an aortic dissection at age 59. In the third family, a 39-year-old woman suffered extracranial ICA and VA dissections, and her brother died at age 48 from an aortic dissection associated with a BAV.

CONCLUSIONS

The familial occurrence of spontaneous arterial dissections and BAV suggests a common developmental defect. The aortic valvular cusps and the arterial media of the aortic arch and its branches are derived from neural crest cells, suggesting that a neural crest defect may be the underlying abnormality in these families.

Sibling risks of abdominal aortic aneurysm

There is evidence that the risk of abdominal aortic aneurysm (AAA) is greater in first-degree relatives of patients with the disorder than in the same age group of the general population. We conducted a 3-year study of siblings of AAA probands and siblings of a control group (cataract surgery patients) of the same age. Genetic information was obtained by interview from 126 probands and 100 controls; another family member was present at the interview. Medical records were obtained and further information verified before a sibling (over age 50) was assigned affected status. Of 427 siblings of probands, 19 (4.4%) had probable or definite AAA, compared with five (1.1%) of 451 siblings of controls. The lifetime cumulative risks of AAA at age 83 were 11.7% (SD 3.1) and 7.5% (4.1), respectively. The risk of AAA began at an earlier age and increased more rapidly for probands' siblings than for controls' siblings (p < 0.01, log-rank test). A risk comparison, based on the results of ultrasound screening of 54 geographically accessible siblings of probands and the 100 controls showed a similar pattern. Ten (19%) siblings of probands and eight (8%) controls had AAA on ultrasound (lifetime cumulative risk 60.8% [18.9] vs 14.9% [5.1], p = 0.01). These results show that familial factors influence the age of onset of AAA. We recommend routine ultrasound examination of siblings of patients with AAA.

A Gly1127Ser mutation in an EGF-like domain of the fibrillin-1 gene is a risk factor for ascending aortic aneurysm and dissection

Ascending aortic disease, ranging from mild aortic root enlargement to aneurysm and/or dissection, has been identified in 10 individuals of a kindred, none of whom had classical Marfan syndrome (MFS). Single-strand conformation analysis of the entire fibrillin-1 (FBN1) cDNA of an affected family member revealed a G-to-A transition at nucleotide 3379, predicting a Gly1127Ser substitution. The glycine in this position is highly conserved in EGF-like domains of FBN1 and other proteins. This mutation was present in 9 of 10 affected family members and in 1 young unaffected member but was not found in other unaffected members, in 168 chromosomes from normal controls, and in 188 chromosomes from other individuals with MFS or related phenotypes. FBN1 intragenic marker haplotypes ruled out the possibility that the other allele played a significant role in modulating the phenotype in this family. Pulse-chase studies revealed normal fibrillin synthesis but reduced fibrillin deposition into the extracellular matrix in cultured fibroblasts from a Gly1127Ser carrier. We postulate that the Gly1127Ser FBN1 mutation is responsible for reduced matrix deposition. We suggest that mutations such as this one may disrupt EGF-like domain folding less drastically than do substitutions of cysteine or of other amino acids important for calcium-binding that cause classical MFS. The Gly1127Ser mutation, therefore, produces a mild form of autosomal dominantly inherited weakness of elastic tissue, which predisposes to ascending aortic aneurysm and dissection later in life.

Aortic dissection: a medical perspective

Over the past 3 years, a greater understanding of predisposing factors and the pathology of the aortic wall has yielded more insights into the pathogenesis, as well as into more accurate diagnostic and preventive methods. This update will discuss: (1) the incidence, definition, and recent classification of aortic dissection; (2) epidemiology, medical, and recent surgical series; (3) the pathogenesis and risk factors; (4) clinical features and evolving noninvasive imaging approaches to diagnosis; and (5) management from a medical perspective.

Abdominal aortic aneurysm, glaucoma and deafness: a new familial syndrome

Several reports have suggested a genetic basis for the distribution of abdominal aortic aneurysm (AAA) in some families. The familial clustering of this disease is further demonstrated in this report of ten siblings, five of whom have confirmed AAA. This is the largest cluster so far reported. The majority of patients in this family group also have glaucoma and/or deafness.

Idiopathic dilatation of the aorta with dissection in a family without Marfan syndrome

Dissection of the aorta is very rare in children, but classically occurs in the presence of Marfan syndrome or other connective tissue disorder. We present a case of spontaneous dissection in a 12-year-old boy whose half brother has an idiopathic dilated aorta and whose mother has also required surgery for dissection of a dilated aorta. No features of connective tissue disorder were present in any family member.

Familial aortic dissecting aneurysm

A family is described in which nine members over two generations had an aortic dissecting aneurysm or aortic or arterial dilation at a young age. The family has been followed up since 1977 after the death of a second teenager from a kindred of 11. None of the patients had the Marfan syndrome or a history of systemic hypertension. Three members died of ruptured aortic dissecting aneurysm and acute hemopericardium at 14, 18 and 24 years of age, respectively; a fourth member died suddenly at age 48 years, a few years after aortic repair for aneurysmal dilation. One member underwent surgical repair of an ascending aortic dissecting aneurysm at age 18 years and is still alive. Four members are currently under close medical observation for aortic or arterial dilation. Histologic examination of the aortic wall at autopsy or surgery in three patients revealed a loss of elastic fibers, deposition of mucopolysaccharide-like material in the media and cystic medial changes. Types I and III collagen from cultured fibroblasts appeared normal on gel electrophoresis. Results of indirect immunofluorescent studies of the elastin-associated microfibrillar fiber array in skin and fibroblast culture from multiple family members were also normal. This dramatic familial cluster of aortic dissecting aneurysm and aortic or arterial dilation suggests a genetically determined disease of autosomal dominant inheritance although the basic defect remains unknown.

Familial aortic dissection: a report of rare family cluster

Acute aortic dissection occurred in three of four siblings without Marfan syndrome. All of them were successfully treated by operation and remain well 6-42 months after operation. Their mother died suddenly in another hospital of acute aortic dissection. All her siblings were dead and cardiovascular disease was suspected in all of them.

Fatal aortic rupture presenting as chest pain in an adolescent. The role of echocardiography in occult cystic medial necrosis

An adolescent female with occult cystic medial necrosis died following spontaneous aortic rupture. A large saccular aortic aneurysm that had ruptured into the pericardial space was demonstrated by two-dimensional echocardiography and confirmed at surgery. Echocardiographic screening of the patient's family members revealed a 13-year-old brother with unsuspected aortic root dilatation. He is now being followed for possible progression of his disease. This case demonstrates the role of echocardiography in cystic medial necrosis. It can aid the acute management of patients with aortic dissection or aneurysm. It can also define patients with occult disease who require serial follow-up and genetic counseling.

Dissecting aortic aneurysm in childhood and adolescence. Case report and literature review

A 15-year-old adolescent male with dissecting aortic aneurysm is presented. His young age, lack of predisposing factors, and fulminant course with rapid progression to death precluded a correct antemortem diagnosis. Review of the literature reveals that most instances of dissecting aortic aneurysm in childhood and adolescence are associated with predisposing conditions, especially congenital cardiovascular anomalies. The clinical picture is generally characteristic. Prompt evaluation and therapy may be lifesaving.

Bilateral subclavian artery aneurysm associated with idiopathic cystic medial necrosis

Although cystic medial necrosis, either idiopathic or associated with Marfan's syndrome, usually becomes manifest as an ascending aortic aneurysm, aortic insufficiency, aortic dissection, or a combination of these disorders, a rare case of bilateral subclavian artery aneurysm secondary to idiopathic cystic medial necrosis has occurred. Subclavian artery aneurysms most commonly represent poststenotic dilatation from anterior scalene or cervical rib compression, occasionally are associated with generalized arteriosclerotic peripheral vascular disease, and rarely are secondary to syphilitic or mycotic infections. Subclavian artery aneurysms have a major risk of rupture, embolus, or thrombosis, and therefore should be repaired. A reverse saphenous vein or prosthetic bypass graft from the carotid to the axillary artery provides adequate flow to the upper extremity. The aneurysm should be completely excised if possible, since reexpansion through small collaterals or through insufficient closure by ligation can occur and compress the brachial plexus after successful bypass. The clinical presentation, angiographic findings, and operative repair of a subclavian artery aneurysm secondary to cystic medial necrosis are described.

Familial abdominal aortic aneurysms

The case histories of three brothers, the only siblings of one family, all of whom underwent surgery for the treatment of a previously asymptomatic ruptured abdominal aortic aneurysm, are recorded. The possibility of underlying constitutional and hereditary factors is discussed and the suggestion of a primary familial incidence of atheromatous, nondissecting aortic aneurysm is raised.