Sinus of Valsalva Aneurysm

Sinus of Valsalva aneurysm (SVA) is an uncommon cardiac anomaly that can be congenital or acquired. John Thurnam first described this condition in 1840. James Hope further described it in 1939.

SVA is usually referred to as a rare congenital anomaly. A congenital SVA is usually clinically silent but may vary from a mild, asymptomatic dilatation detected on routine two-dimensional echocardiography to symptomatic presentations related to the compression of adjacent structures or intracardiac shunting caused by rupture of the SVA into the right side of the heart. Approximately 65-85% of SVAs originate from the right sinus of Valsalva, whereas SVAs originating from noncoronary (10-30%) and left sinuses (< 5%) are exceedingly rare.[1]  SVA is commonly associated with aortic valve regurgitation and/or ventricular septal defect.[2]

Congenital sinus of Valsalva aneurysm (SVA) is caused by a dilation, usually of a single sinus of Valsalva, from a separation between the aortic media and the annulus fibrosus. A deficiency of normal elastic tissue and abnormal development of the bulbus cordis have been associated with the development of SVA.[3] Other disease processes that involve the aortic root (eg, atherosclerotic aneurysms, syphilis, endocarditis, cystic medial necrosis, chest trauma) may also produce SVA, although this usually involves multiple sinuses. Rupture of the dilated sinus may lead to intracardiac shunting when a communication is established with the right atrium (Gerbode defect [10%]) or directly into the right ventricle (60-90%). Cardiac tamponade may occur if the rupture involves the pericardial space.[4]

Primary causes of sinus of Valsalva aneurysm (SVA) are congenital.

Secondary causes include the following:

• Atherosclerosis
• Syphilis
• Cystic medial necrosis or Marfan syndrome
• Blunt or penetrating chest injury
• Infective endocarditis

Associated congenital defects include the following:

• Ventricular septal defect
• Aortic insufficiency
• Coarctation

United States data

Sinus of Valsalva aneurysm (SVA) was present in 0.09% of cadavers in a large autopsy series and ranged from 0.14% to 0.23% in a Western surgical series.[5] Two-dimensional echocardiography is likely to determine a higher incidence of SVA, although researchers note the incremental value of three-dimensional echocardiography.[6]

International data

SVA is more prevalent in Asian surgical series (0.46-3.5%) and correlates with more supracristal ventricular septal defects (about 60%).[7]

Race-, sex-, and age-related demographics

Race differences in SVA are unclear, although a higher frequency has been observed in the Asian surgical series.

There is a 4:1 male-to-female ratio, including frequencies of both ruptured and unruptured SVA.

Unruptured SVA is usually asymptomatic and is often detected incidentally by routine two-dimensional echocardiography, even in patients older than 60 years. Most ruptured SVAs occur from puberty to age 30 years and are often diagnosed or presented clinically at this age.

A retrospective review of an institutional database that identified 86 patients who underwent SVA repair from 1956 to 2003 found the median age to be 45 years (range 5-80 years).[8]

The prognosis for patients with sinus of Valsalva aneurysm (SVA) is poor with progressive aneurysmal dilatation or rupture unless early surgical repair is performed.[9]

Actuarial survival rate for patients with congenital SVA is 95% at 20 years, since most SVAs do not rupture prior to age 20 years.

Unruptured SVA has been observed in serial monitoring up to several years after initial diagnosis, but most unruptured SVAs have been found to progress and/or rupture.

In a series of 86 patients who underwent SVA repair, ruptures occurred in 34%.[8] Six (7%) died perioperatively; the actuarial 10-year survival rate was 63%. These patients often required concomitant surgical repair of associated ventricular septal defect, atrial septal defect, and the aortic valve.[8]

Another series reported comparable outcomes after surgical repair.[10] Of 65 patients aged 5-50 years undergoing surgical repair of SVA, the 30-day postoperative survival was 92%. Of the remaining patients, all survived to 1 year and two had complications: one with septic shock due to endocarditis and one with paraprosthetic regurgitation.[10]

In a series of 25 patients undergoing transcatheter closure of ruptured SVA, procedural success was 84%.[11]  One closure device embolized, two patients had residual leak, and three were referred to surgery.

Morbidity/mortality

The true natural history of SVA remains unclear. Clinical complications from SVA are often the initial presentation of this condition.

Complications of SVA include the following:

• Potential risks of expansion, rupture, cardiac failure, and sudden death.
• Myocardial infarction (from coronary arterial compression by adjacent unruptured SVA)
• Complete heart block (from compression of conduction tissues by adjacent unruptured SVA)
• Right ventricular outflow tract obstruction
• Infective endocarditis
• Tamponade if ruptured into the pericardium
• Potential source of cerebrovascular emboli (rare)

Associated structural defects in congenital SVAs included supracristal or perimembranous ventricular septal defect (30-60%), bicuspid aortic valve (15-20%) and aortic regurgitation (44-50%).[12, 13] Approximately 10% of patients with Marfan syndrome have some form of SVA. Less commonly observed anomalies include pulmonary stenosis, coarctation, and atrial septal defects.

Rupture of SVA (with progressive heart failure and left-to-right shunting or endocarditis) is the main cause of death and rarely occurs before age 20 years in congenital SVA.

Nonruptured sinus of Valsalva aneurysms (SVAs) are most often asymptomatic (25%) and found incidentally in routine two-dimensional echocardiography. However, patients can eventually develop nonspecific complaints, such as dyspnea, chest pain, palpitations, or loss of consciousness. Dyspnea is by far the most common presenting symptom.

When aneurysms are large enough, they can compress on neighboring structures, thereby causing arrhythmias, or they can obstruct the left or right ventricular outflow tracts, causing palpitations or syncope. Also, a thrombus can develop within the aneurism and occlude the coronary ostia and present as acute coronary syndrome, or it can dislodge and embolize to the brain and cause a stroke.

When the dilated sinus does rupture (precipitated by exertion, trauma, or cardiac catheterization), consequences depend on the location of the aneurysm. Patients may present dramatically with abrupt hemodynamic collapse, or the presentation may have a subtle onset. Most right coronary sinus aneurysms rupture into the right ventricular outflow tract, although an aorta-to-right atrium communication may also result. Left sinus aneurysms usually rupture into the left atrium. Rupture of noncoronary sinus aneurysms normally result in communication between the aorta and the right atrium or the right ventricle, thus creating a left-to-right shunt, which can lead to right ventricular overload and eventual right-sided heart failure. SVA rupture into the interventricular septum, with consequent left ventricular outflow tract obstruction, has also been reported.[2]  Cardiac tamponade is a feared complication that may occur with any of the three types of aneurysms if the rupture involves the pericardial space.[4]

A ruptured SVA progresses in the following three stages, as described by Blackshear and colleagues[14] :

• Acute chest or right upper quadrant pain
• Subacute dyspnea on exertion or at rest (heart failure syndrome) with progressive or acute onset
• Progressive cough, dyspnea, edema, and oliguria

Atypically, SVA presents with infective endocarditis, which may originate at the edges of the aneurysm.

Unruptured sinus of Valsalva aneurysms (SVA) is often asymptomatic and has almost no physical signs. When SVA ruptures, few specific signs of left-to-right shunting may become apparent, and these are often indistinguishable from coronary arteriovenous fistula. Clinical suspicion followed by prompt echocardiographic confirmation is key to diagnosis.

Signs of SVA include the following:

• A loud, superficial, "machine-type" continuous murmur is accentuated in diastole in as many as 40% of patients.
• A palpable thrill along the right or left lower parasternal border is occasionally noticeable.
• Bounding pulses are occasionally present.
• In one series, approximately 44% of the patients had associated aortic regurgitation. ^[8]

Transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) have traditionally been used to diagnose sinus of Valsalva aneurysm (SVA), but electrocardiography (ECG)-gated computed tomographic angiography (CTA) and cardiac magnetic resoance imaging (CMRI) have gained popularity in recent decades.[2, 17]

Multiplane TEE provides conclusive information regarding SVA and allows precise identification of structural anomalies and shunt locations for perioperative assessment.[3, 14]

Two-dimensional TTE may detect as many as 75% of all patients with SVA.[18, 19] Color-flow Doppler imaging is considered the technique of choice for identifying a ruptured SVA. However, the use of contrast echocardiography is helpful in delineating the aneurysm and shunt arising from rupture. The presence of a left-to-right shunt can be confirmed by demonstrating a negative contrast image in the right-sided cavities. Usually TEE, EGG-gated CTA, or CMRI is needed to confirm the diagnosis and for perioperative assessment.

Features of SVA on TTE include the following:

• Generalized single sinus enlargement
• "Wind-sock" extension of the sinus from the body and/or apex of an otherwise normal aortic sinus when ruptured
• Detection of associated defects, including ventricular septal defect, bicuspid aortic valve, and aortic insufficiency

ECG-gated CTA and CMRI may provide valuable three-dimensional data for procedural planning.

Electrocardiography usually reveals sinus tachycardia, although conduction defects may occur.

Although rarely necessary, the definitive diagnosis of sinus of Valsalva aneurysm can be confirmed by performing a retrograde thoracic aortography or cardiac catheterization. Left-to-right shunting also can be demonstrated if the SVA is ruptured.

In the 2018 American Heart Association/American College of Cardiology (AHA/ACC) guideline for the management of adults with congenital heart disease, sinus of Valsalva aneurysm (SVA) is classified as a lesion with moderate anatomic complexity. No specific recommendations are provided to guide evaluation or treatment.[20]

Similarly, the 2020 European Society of Cardiology (ESC) guidelines for the management of adult congenital heart disease also categorize SVA as being of moderate anatomic complexity, and no specific diagnostic or management recommendations are laid out.[12, 13]

Medical management of sinus of Valsalva aneurysm (SVA) usually involves clinical stabilization (eg, optimizing medications for heart failure syndrome) and perioperative assessment and management.[14]

Transcatheter closure of ruptured SVA has been successfully performed using Amplatzer devices.[21, 22, 23] Ruptured SVAs have been treated with transcatheter closure to avoid sternotomy and cardiopulmonary bypass in critically ill patients.

Although advanced percutaneous techniques have been performed in the correction of this anomaly, open-heart surgery with or without aortic valve replacement remains the standard of care. A surgical approach may also allow additional procedures such as aortic root replacement or ventricular septal defect closure.[10, 12, 13]

Cardiothoracic surgery consultation is urgent in patients with ruptured sinus of Valsalva aneurysm (SVA), because clinical deterioration can be rapid.

Conventionally, with an operative mortality below 2%, surgical repair of the ruptured SVA has been the mainstay of therapy. Urgent surgical repair is recommended in all patients with ruptured SVA, especially with intracardiac shunting.[24, 25, 26] Aggressive surgical correction of unruptured SVA is often recommended because of the lesion's association with increased morbidity and mortality.[8, 27, 9, 28, 29, 30]

Surgical repair may include the following procedures:

• Aortic root reconstruction or replacement
• Aortic valve repair or replacement
• Bentall procedure (valved conduit)
• Ventricular septal defect repair (if present)
• Atrial septal defect repair (if present)
• Primary suture closures (pledget) and patch closures (if ruptured)

Surgery is the definitive therapy for sinus of Valsalva aneurysm (SVA). Depending on the clinical presentation, perioperative medical management consists of (1) relieving heart failure symptoms; (2) treating arrhythmia, if present; and (3) treating endocarditis, if present. The reader is encouraged to read corresponding articles for appropriate medication therapy.

See the American Heart Association (AHA) and/or American College of Cardiology (ACC) guidelines on:

• Infective endocarditis in adults: diagnosis, antimicrobial, and management of complications (2015)
• Prevention of infective endocarditis in childhood (2015 update)
• Management of patients with valvular heart disease (2014)