Sinus of Valsalva aneurysm

A sinus of Valsalva aneurysm refers to abnormal dilatation of the sinus of valsalva and is a cause of thoracic aortic dilatation. Sinus of Valsalva aneurysms arise from one of the aortic sinuses. They are either congenital or acquired.

Epidemiology

There is a male predilection (M:F ratio being around 3-4:1). They are relatively more common in eastern and Asian populations and can occur in any age group with a mean age of 35 years at presentation ⁴.

Associations

Commonly occur with other congenital heart anomalies, including:

• ventricular septal defects
• bicuspid aortic valve
• pulmonic stenosis

Clinical presentation

They may be asymptomatic. Presentation with a catastrophic acute rupture is quite common. Dyspnoea, chest pain and palpitations and cardiac murmurs may occur ⁴.

Pathology

Aetiology

Sinus of Valsalva aneurysm may be either congenital or acquired. Congenital causes include:

• Marfan's syndrome
• collagen vascular disease
  • Ehlers-Danlos syndrome
• vasculitis
  • Takayasu arteritis

Acquired causes include:

• infection
  • infective endocarditis
  • syphilis
• atherosclerosis
• iatrogenic
• traumatic

Location

They most often involves the right coronary sinus, less frequently the non-coronary sinus and rarely left coronary sinus ³.

Radiographic features

They are saccular and arise above the aortic annulus.

Cardiac MRI/CT

MRI is considered the imaging modality of choice, especially with the mycotic type. The saccular aneurysm is seen arising from one of the sinus (right coronary sinus being the most common location) and protruding into adjacent cardiac chamber. 

The normal sinus diameter upper limit is usually taken as 40 mm (with some publications suggesting 36 mm for females) ⁶.

Echocardiography

Transoesophageal echocardiography is preferred for anatomical delineation of the origin of the aneurysm, which will appear on two-dimensional imaging as a mobile, thin walled structure, circular in short axis, protruding from above the plane of the coronary artery origins into an adjacent cardiac chamber. The appearance is classically described as a "windsock" deformity with enlargement during systole ⁸.

Filling of the aneurysm may be observed with colour flow Doppler, and the use of contrast may aid in the visualizationvisualisation of the left-to-right shunt, as well as differentiating between ruptured and unruptured aneurysms ⁹. The use of spectral Doppler allows quantification of flow velocity and direction; rupture into a cardiac chamber with subsequent shunting typically yields constant flow from the aorta to the lower pressure chamber throughout the cardiac cycle, potentially allowing differentiation from other intracardiac shunts e.g. ventricular septal defects ¹⁰.

Treatment and prognosis

Surgical repair with a Bentall procedure could be performed.

Complications

• rupture
  • most commonly into right ventricle
  • may lead to cardiac tamponade +/- intracardiac shunting
• ventricular outflow tract obstruction
• aortic regurgitation
• myocardial ischemiaischaemia
• arrhythmias 
• endocarditis