MDCT- Angiogram in unruptured aneurysm of sinus of valsalva – A pictorial essay

A 34-year-old patient came to casualty with complaints of acute chest pain and breathlessness for few hours without any comorbidities. His Respiratory Rate was 27/min and supplemental O2 was given. ECG was normal and ECHO showed large aneurysmal sac near aortic sinus.

MDCT Aortogram was done. Plain CT showed Cardiomegaly, Bilateral Normal Lung fields and no pleural effusion. Arterial phase showed a large aneurysmal sac measuring 4.8 (anteroposterior) x 4.7 (transverse) x 7.2 (craniocaudal) cm arising from right sinus of Valsalva with neck measuring 2.8cm and extending into Right Ventricular Outflow Tract (RVOT) [Fig:1] underneath the anterior wall of Right Ventricle just below the Pulmonary Valve (Sakakibara Type: I) with an eccentric thrombus noted within the sac. Right coronary artery seen to be originating from right anterior aspect of the right sinus [Fig: 2].  Left sinus seen which showed  normal origin of left coronary artery. Non coronary sinus was visualized and it was normal. No evidence of any dissection. Rest of the Aorta appears normal in caliber and no abnormalities made out. The Main Pulmonary artery measures 3.2cm and Right and Left branches measures 2.1cm and 2.2 cm respectively. Atrial and Ventricular chambers appear normal.

BACKGROUND:    Valsalva Aneurysms are rare and may be Congenital or Acquired. Congenital aneurysms are either due to weakness of elastic tissues or deficiency of elastic tissues. Acquired causes are mostly post-infectious (bacterial, syphilis, tuberculosis or degenerative causes like atherosclerosis, cystic medial necrosis and trauma). Accurate and prompt diagnosis is needed as both ruptured and unruptured aneurysms can lead to potentially fatal complications.

CLINICAL PERSPECTIVE: SOV aneurysms can arise from Right , Left or Non-coronary sinus. Men are involved more than Female (middle-aged males). Depending on the size of aneurysm, rapidity of rupture and cavity into which it ruptures determines the symptom during the time of presentation including severe chest pain, dyspnoea, cardiac failure, volume overload. The symptoms are more common and severe in ruptured types whereas unruptured types are usually asymptomatic. Complications include Aortic Regurgitation  (most common) and can also involve any valves depend upon its extension into the chambers and the proximity of the aneurysm to the valve. Non-ruptured aneurysm may  manifest due to its mass effect in adjacent chambers. Myocardial ischemia and infarction occur due to occlusion  or compression of coronary artery[1]. Rupture most commonly occur into Right ventricle leading to aortocardiac shunting and immediate heart failure. Rupture can also occur into Right atrium, Right ventricular outflow tract, Left ventricle, Left atrium, Interventricular Space, Pericardial space, Pulmonary artery in descending order respectively. Thus Radiological Imaging becomes mandatory in an emergency setting if ECG and ECHO were inconclusive. The Radiologist should report the primary cause for the Acute Chest Pain and also any complications if any.

IMAGING PERSPECTIVE:

SAKAKIBARA CLASSIFICATION: [2]

Type: I            Originating from left part of right coronary sinus; protruding into conus of right ventricle, just beneath commissure of right and left pulmonary valves

Type: II          Originating from central part of right coronary sinus; protruding into right ventricle; penetrating crista supraventricular

Type: III v      Originating from posterior part of right coronary sinus; protruding into right ventricle, just beneath septal leaflet of tricuspid valve;

Type: III a      Originating from the posterior part of right coronary sinus; protruding into right atrium, near commissure of septal and anterior leaflets of tricuspid valve

Type: IV         Originating from right part of noncoronary sinus; protruding into right atrium, near septal leaflets of tricuspid valve.

OUTCOME: Emergency Aortic Valve Repair was done and intraoperatively large globular aneurysm was seen arising from Right Sinus extending into RVOT (Fig:5) below the Pulmonary valve. Postoperatively vitals stable and patient was discharged.