Pediatric Sinus of Valsalva Aneurysm


Background

Congenital sinus of Valsalva aneurysm [1was first described by Hope in 1839. [2This first published account describes rupture of a sinus of Valsalva, which is the most feared complication. Soon afterwards, clinicians described other cases of unruptured aneurysms and applied anatomic descriptions. The condition may have been clinically described for the first time in 1883. [2]

The 3 sinuses of Valsalva are located in the most proximal portion of the aorta, just above the cusps of the aortic valve. The sinuses correspond to the individual cusps of the aortic valve. These structures contained within the pericardium are easily revealed using aortography and echocardiography as distinct but subtle out-pouchings of the aortic wall just above the valve. The sinuses end in the area of the sinotubular junction, and the tubular portion of the aorta begins here.

Aneurysm of a sinus of Valsalva is a rare congenital cardiac defect that can rupture, causing heart failure or other catastrophic cardiac events. If the aneurysm remains unruptured, it occasionally causes obstruction of cardiac flow resulting from compression of normal structures. Dissection of the aneurysm into the cardiac tissues may occur, causing obstruction or destruction of local structures.

Acquired aneurysmal dilatation of the sinuses of Valsalva may occur because of Marfan syndrome, syphilitic aortitis, or as a function of aging. These entities are not discussed in this article. See the image below.

Sinus of Valsalva aneurysm. Color-flow Doppler ultSinus of Valsalva aneurysm. Color-flow Doppler ultrasonography is performed in the right ventricle through a supracristal ventricular septal defect with fingerlike prolapse of the right coronary sinus wall (arrow).

Pathophysiology

Aneurysmal dilatation of the sinuses of Valsalva occurs when the aortic media is defective, allowing separation of the media from the aortic annulus fibrosus. [3The defect is inherited, but frank aneurysmal dilatation is rarely seen at birth. Sinus of Valsalva aneurysm is associated with a ventricular septal defect in approximately 40% of patients.

Aneurysms typically develop as a discrete flaw in the aortic media within one of the sinuses of Valsalva. Aneurysms most often involve the right aortic sinus (67-85% of patients, often associated with a supracristal ventricular septal defect), followed by the noncoronary sinus, whereas an aneurysm of the left sinus is rare. [3Under the strain of aortic pressure, the sinus gradually weakens and dilates, causing the formation of an aneurysm. Lack of supporting tissue (eg, ventricular septal defect) may contribute to instability and progressive distortion of the aortic sinus, often with associated aortic insufficiency. Deficiency of the aortic media where it attaches to the aortic annulus produces dilation of the aortic sinuses, usually over many years.

Distortion and prolapse of the sinus and aortic valve tissue can lead to progressive aortic valve insufficiency. Unruptured aneurysm may cause distortion and obstruction in the right ventricular outflow tract. Distortion and compression may also cause myocardial ischemia (by coronary artery compression) and, possibly, heart block (by compressing the conduction system). Rupture may occur into any chamber, although rupture most commonly occurs into the aortic right ventricular communication. Rupture into the right atrium is the second most common, in association with a noncoronary cusp aneurysm. Rupture may occur less commonly into the left-sided chambers, [4the pulmonary artery, [5and rarely extends into the pericardium.

Epidemiology

Frequency

United States

Sinus of Valsalva aneurysm comprises approximately 0.1-3.5% of all congenital cardiac anomalies. Discovery in the pediatric age group is unusual.

International

Incidence in the Western Hemisphere (outside of the United States) is approximately the same as in the United States. An increase in prevalence is observed in Asians because of the higher incidence of supracristal (subpulmonic) ventricular septal defects.

Mortality/Morbidity

Morbidity and mortality are most often associated with acute severe aortic valve insufficiency resulting from aneurysm rupture. The mortality rate in patients with a sinus of Valsalva aneurysm in whom surgery is not performed is high within the first year after rupture. [367]

Causes of sudden death from sinus of Valsalva aneurysm most commonly involve rupture of the aneurysm with the acute onset of overwhelming congestive heart failure, cardiac tamponade, dysrhythmia, or coronary ischemia, depending on the location of the aneurysm and the subsequent flow disturbance. Size and location of the shunt are the major determinants of presentation and prognosis. Late death usually occurs within 1 year after rupture if the shunt is substantial; longer survival may occur if the shunt is small. [78]

Major cardiac morbidity and late mortality in this condition also depend on the magnitude and location of shunts. In some instances, an unruptured aneurysm also causes major symptoms and hemodynamic alterations because of obstruction of valves or impingement upon cardiac structures (eg, coronary arteries, conduction system).

The surgical mortality rate is estimated to be 5% or less.

Race

Increased incidence in the Asian population has been described, which is the result of increased incidence of supracristal ventricular septal defect in Asian persons. These ventricular defects may contribute to instability of the aortic sinuses, particularly the right aortic sinus.

Sex

Male-to-female ratio is 4:1.

Age

Average age of patients with rupture of a sinus of Valsalva aneurysm is approximately 30 years, with a range of 11-67 years in one series. Problems in infancy and childhood are uncommon.

CLINICAL PRESENTATION


History

Children with sinus of Valsalva aneurysm are most often asymptomatic. Symptoms typically present in young adulthood (usually in patients < 30 y) either due to enlargement of the aortic root and compression of surrounding structures or due to manifestations of a ruptured aneurysm. Three clinical pictures may be associated with sinus of Valsalva aneurysm, as follows:

  • Sudden massive rupture may occur after strenuous exertion and may be signaled by acute chest or epigastric pain with dyspnea. Symptoms may be confused with those of acute myocardial infarction. [3]

  • Patients with a smaller insidious rupture may be asymptomatic, but small ruptures also may be associated with progressive symptoms of exertional dyspnea and/or chest discomfort from advancing heart failure. [9]

  • Patients with unruptured aneurysms may be asymptomatic. Angina may occur secondary to coronary compression resulting from an unruptured aneurysm. Syncope or dizziness may be caused by aneurysm compression of the conduction system, with associated heart block (Adams-Stokes syndrome).

Physical

Positive physical findings may be absent in a patient with an unruptured sinus of Valsalva aneurysm. Physical signs of a ruptured aneurysm vary, depending on the location of the shunt, and may mimic signs observed in a patient with a sizable coronary arteriovenous (AV) fistula. Physical signs may include the following [10:

  • A loud continuous murmur, accentuated in the diastole, occurs with aneurysm rupture into the right ventricle or right atrium. The systolic component of the continuous murmur is usually heard best higher in the chest, whereas the diastolic component may be best heard lower along the sternal border.

  • A parasternal thrill is heard from associated ventricular septal defect with large volume of runoff or, possibly, outflow obstruction.

  • Bounding pulses occur as a result of aortic runoff into lower-pressure chambers.

  • Shunt from the aortic root to the left ventricle may produce a diastolic murmur similar to that of aortic insufficiency.

  • Pulmonary rales may be present from progressive left heart failure.

  • With an unruptured aneurysm partially obstructing the right ventricular outflow tract, an ejection murmur may be heard at the left base radiating into the back.

Causes

Sinus of Valsalva aneurysm is presumed to be caused by a spontaneous genetic mutation. Although the defect is inherited, no distinct pattern of inheritance has been noted. Frank aneurysmal dilatation is rarely seen at birth.

Subpulmonic ventricular septal defect may be an important contributing factor in the progression of sinus of Valsalva aneurysms.

Tertiary syphilis is of historical significance as a cause for aortic aneurysms.

Traumatic injury to the aortic root (usually from direct chest compression) may rarely cause rupture of the aortic root.

A number of generalized disorders may be associated with dilatation and/or distortion of the aortic root, including Marfan syndrome, Ehlers-Danlos syndromeTurner syndromeWilliams syndromeaortic valve, bicuspid, and osteogenesis imperfecta.

DDx


Diagnostic Considerations

Carefully assess a child under evaluation for a new heart murmur, especially if a diastolic murmur is discovered: The vast majority of "innocent" murmurs are systolic, and the discovery of a new diastolic murmur warrants further investigation.

Carefully evaluate a complaint of new onset of chest pain, fatigue, or exertional dyspnea, with special attention to examination of the cardiovascular system: Again, the development of a new heart murmur should always prompt an investigation into the cause, particularly if the murmur is diastolic.

Investigate any abnormal findings depicted on routine radiographs (eg, those obtained during sports examination), such as cardiomegaly or a dilated aorta.

Take a careful family history in any child discovered to have an aneurysm of a sinus of Valsalva (ruptured or unruptured): This aneurysm is often difficult to distinguish clinically from Marfan syndrome, particularly if the aneurysm is unruptured.

Discourage patients with a sinus of Valsalva aneurysm from participation in contact sports or activities involving vigorous exertion

Other conditions to consider

When evaluating patients with suspected sinus of Valsalva aneurysm consider the following conditions:

  • Traumatic injury to the aortic root (usually from direct chest compression)

  • Tertiary syphilis

  • Acute infective endocarditis: Ruptured sinus of Valsalva aneurysm may be confused with, or precipitated by, acute infective endocarditis (see Endocarditis, BacterialEndocarditis, Fungal).

Successful pregnancy has been reported in women with ruptured sinus of Valsalva aneurysms with appropriate, careful management of labor and delivery. Surgical repair of ruptured aneurysm during pregnancy has been reported. [11]

The disorder is rare enough in the Western Hemisphere that data on recurrence risk for offspring of mothers or fathers with sinus of Valsalva aneurysm have not been reported.

Differential Diagnoses

Workup

Laboratory Studies

No specific serologic or genetic markers have been identified for sinus of Valsalva aneurysm.

Serum electrolyte levels are helpful in long-term treatment of heart failure using diuretics, ACE inhibitors, or both.

Imaging Studies

If physical findings are suggestive of a sinus of Valsalva aneurysm, patients may be evaluated using a combination of 2-dimensional echocardiography, 3-dimensional echocardiography, CT scanning, MRI, and chest radiography.

Echocardiography

Two-dimensional Doppler echocardiograms reveal the proximal aorta, sinuses, aortic valve, and surrounding structures. [12Doppler findings may provide an accurate indication of the shunt location and magnitude. Three-dimensional echocardiography may be helpful in the planning of appropriate surgical or transcatheter approach.

Echocardiography may be helpful in evaluating adolescent and adult patients with supracristal ventricular septal defects for high-risk features (eg, aneurysm of Valsalva rupture) for surgical planning. [13]

Transesophageal echocardiography may be required in young adults and adults to optimally depict cardiac structures. Continuous rotation using a multiplanar transducer may be particularly helpful to define the exact point of rupture. Transesophageal echocardiography may be used for more detailed diagnosis of anatomy and blood flow in adult patients. [14]

Angiography

Coronary angiography can help assess the presence of coronary anomalies or coronary artery compression.

Radiography

Chest radiography may reveal cardiomegaly. Right heart enlargement is seen with rupture from the aorta into the right ventricle. Rarely, the left side of the aortic root may be enlarged with rupture from the aorta into the left ventricle.

Pulmonary congestion may be depicted in patients with progressive cardiac failure.

Magnetic Resonance Imaging

MRI can facilitate identification of both a ruptured and an unruptured sinus of Valsalva aneurysm. Cine phase-contrast MRI can be used for assessment of insufficiency and shunt flow.

Black blood studies may be helpful for assessment of ascending aortic flow abnormalities or valve or root morphology.

Other Tests

ECG may reveal biventricular hypertrophy in a patient with a ruptured aneurysm. Myocardial ischemia may be demonstrated by ST-T depression.

Conduction system involvement may be identified by second-degree or third-degree heart block.

Procedures

If physical findings are suggestive of a sinus of Valsalva aneurysm, patients may be evaluated using cardiac catheterization. Cardiac catheterization with coronary and aortic angiography allows quantitation of shunts, cardiac outputs, and hemodynamics.

Histologic Findings

Histologic examination of aortic tissue may reveal medial degeneration.

TREATMENT AND MANAGEMENT


Medical Care

Direct the medical care of the patient with a ruptured sinus of Valsalva aneurysm toward hemodynamic stabilization, prevention or treatment of endocarditis, and management of arrhythmias, cardiac ischemia, or both using the following indications and medications [39:

  • Heart failure: Administer diuretics, digitalis, and ACE inhibitors, and perform stabilization of cardiac rhythm (as indicated).

  • Cardiac ischemia: Administer nitrates and beta-blockers.

  • Endocarditis: Standard prophylaxis is no longer routinely recommended. Standard prophylaxis should be used after an episode of bacterial endocarditis has occurred to prevent reoccurrence. [15For more information, see Antibiotic Prophylactic Regimens for Endocarditis.

Surgical Care

Prompt surgical therapy is recommended when a ruptured sinus of Valsalva aneurysm is diagnosed. A combined approach from the affected chamber and from inside the aorta is most helpful to allow inspection of the aortic valve and to avoid injury to the coronary vessels. The procedure is described as follows: [161718]

The fistula tract from the ruptured aneurysm is closed, and an associated ventricular septal defect can be repaired.

The aorta is reunited with the valve annulus either by direct anastomosis or by the interposition of a graft, if required. Competency of the aortic valve is tested using transesophageal Doppler ultrasound, and valve repair can be undertaken, if necessary. Preservation of the aortic valve, particularly in children, is of paramount importance; therefore, early surgical intervention may be warranted.

No consensus as to when to perform surgery on a fortuitously discovered unruptured sinus of Valsalva aneurysm has been reached. Regular follow-up of these patients using echocardiography or MRI to document the size of the aneurysm is indicated. Undertake elective repair of a known sinus of Valsalva aneurysm at the same time as surgical repair of any other intracardiac shunt or defect.

Although surgical closure is generally indicated and reserved for patients with ruptured sinus of Valsalva, particularly complicated cases (eg, severe aortic regurgitation, complex lesions [endocarditis, bicuspid aortic valve, tunnel-type fistulous connections, large defects, multiple rupture sites]), percutaneous closure has been found to be safe and effective in patients who are not candidates for bypass, have mild/absent aortic regurgitation, simple associated defects (eg, muscular ventricular septal defects, secundum atrial septal defect, small patent ductus arteriosus). [19]

Percutaneous, transcatheter closure of a ruptured sinus of Valsalva aneurysm was first described in 1994. [20Numerous occluder devices have been used, especially the Amplatzer device. [21222324Guidance for transcatheter closure is provided by 2-dimensional or 3-dimensional transesophageal echocardiographic guidance. [23]

Although the traditional approach for transcatheter closure is antegrade, successful closure with a retrograde approach has also been reported. [25]

Activity

Patients with a sinus of Valsalva aneurysm should avoid participation in contact sports or activities involving vigorous exertion or sustained heavy lifting. Chest trauma may precipitate rupture of a sinus aneurysm.

Patients with ruptured aneurysms who are awaiting surgical repair can be allowed activity to tolerance levels. Activity may be limited because of symptoms of congestive heart failure.

MEDICATION


Medication Summary

No specific medical therapy is indicated for sinus of Valsalva aneurysm. Treatment of congestive heart failure may be required if rupture of the aneurysm occurs into the right heart chambers; standard therapy for heart failure is recommended, [326although surgery is the treatment of choice.

Angiotensin-converting enzyme (ACE) inhibitors

Class Summary

Chronic rupture of a sinus of Valsalva aneurysm may produce protracted symptoms and findings of congestive heart failure. ACE inhibitors and angiotensin receptor blockers (ARB) have been shown to be effective in the treatment of long-standing aortic insufficiency. ACE inhibitors and ARBs are beneficial in all stages of chronic heart failure. Pharmacologic effects provide both preload and afterload reduction and may have beneficial effects in the prevention of pathologic hypertrophy from volume overload.

Captopril (Capoten)

Prevents conversion of angiotensin I to angiotensin II, a potent vasoconstrictor, resulting in lower aldosterone secretion.

Note: May be placed into stabilized suspension with water and ascorbic acid.

Lisinopril (Prinivil, Zestril)

Prevents conversion of angiotensin I to angiotensin II, a potent vasoconstrictor, resulting in lower aldosterone secretion.

Cardiac glycosides

Class Summary

Digitalis remains useful in the treatment of chronic heart failure. Cardiac glycosides are positive inotropic agents that increase the force of contraction of the myocardium and are used to treat acute and chronic congestive heart failure. Cardiac glycosides have been implicated in improving chemoreceptor function, thus potentially increasing exercise tolerance in patients with heart failure.

Digoxin (Lanoxin, Lanoxicaps)

Useful in slowing and stabilizing heart rate, particularly at the atrioventricular node. Acts directly on cardiac muscle, increasing myocardial systolic contractions. Indirect actions result in increased carotid sinus nerve activity and enhanced sympathetic withdrawal for any given increase in mean arterial pressure.

Diuretic agents

Class Summary

These agents promote excretion of water and electrolytes by the kidneys and are used to treat heart failure or hepatic, renal, or pulmonary disease when sodium and water retention have resulted in edema or ascites. Both oral and parenteral diuretics may be helpful in the management of congestive heart failure.

Furosemide (Lasix)

Loop diuretic that increases excretion of water by interfering with chloride-binding cotransport system, which, in turn, inhibits sodium and chloride reabsorption in the ascending loop of Henle and distal renal tubules.

Used commonly for acute and long-term management of congestive heart failure.

Hydrochlorothiazide (HydroDIURIL, Microzide)

Inhibits reabsorption of sodium in distal tubules, causing increased excretion of sodium and water, as well as potassium and hydrogen ions.

Spironolactone (Aldactone)

Competes with aldosterone for receptor sites in distal renal tubules, increasing water excretion while retaining potassium and hydrogen ions. Has positive effect on neurohumoral mechanisms in congestive heart failure and may be helpful in remodeling in pathologic hypertrophy.

Beta-adrenergic receptor blockers

Class Summary

These agents inhibit chronotropic, inotropic, and vasodilatory responses to beta-adrenergic stimulation. They are used for their effect on reducing myocardial oxygen consumption in congestive heart failure. Beta-blockers also counteract the sympathetic overdrive of congestive heart failure.

Metoprolol (Lopressor)

Selective beta1-adrenergic receptor blocker that decreases automaticity of contractions.

Carvedilol (Coreg)

Blocks beta1-adrenergic, alpha-adrenergic, and beta2-adrenergic receptor sites. Recently introduced to treat congestive heart failure. Therapeutic trials are currently underway in pediatric patients in the United States.

Nitrates

Class Summary

Nitrates are peripheral and coronary vasodilators used in the management of angina pectoris, heart failure, and myocardial infarction. When given orally or sublingual, these agents reduce preload and improve myocardial oxygen supply and demand.

Nitroglycerin sublingual (Nitrostat)

Causes relaxation of vascular smooth muscle by stimulating intracellular cyclic guanosine monophosphate production. Administered acutely or in SR preparations for relief of myocardial ischemia and for reduction of preload and afterload. PO/SL forms rarely are administered in infants or children.

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