bubble_chart Overview

Rupture of the aortic sinus aneurysm is a rare congenital heart disease. Reported incidence is higher in Eastern countries than in Western countries, accounting for 1/100 to 2/100 of congenital heart diseases in China. Hope first described this condition in 1839. In 1958, McGoon, Kirklin, and others reported successful repair under extracorporeal circulation. During embryonic development, due to hypoplasia of the base of the aortic sinus, the middle layer of the sinus wall lacks sufficient elastic fibers and muscle tissue, resulting in a discontinuity between the aortic wall's middle layer and the aortic valve fibrous ring. This creates a weak point at the base of the aortic sinus. After birth, aortic blood pressure gradually pushes outward at the weakened area of the aortic sinus, forming an aneurysm-like protrusion. Eventually, rupture occurs with or without physical exertion or trauma, leading to the formation of a ruptured aortic sinus aneurysm. Aortic sinus aneurysms often appear sac-like with a perforated apex. Rupture most commonly occurs in the right coronary sinus, followed by the non-coronary sinus, while rupture in the left coronary sinus is rare. Due to anatomical relationships, right coronary sinus aneurysms mostly rupture into the right ventricular cavity (about 70%), with a minority rupturing into the right atrial cavity. In contrast, non-coronary sinus aneurysms mostly rupture into the right atrial cavity (about 70%), with a minority rupturing into the right ventricular cavity.

bubble_chart Pathological Changes

When an aortic sinus aneurysm ruptures, it usually ruptures into the right low-pressure cardiac chamber. Blood flows from the high-pressure aorta into the low-pressure right ventricular cavity. Due to the significant pressure gradient between the two, a large left-to-right shunt occurs. The resulting hemodynamic changes resemble those of a patent ductus arteriosus, with increased pulmonary blood flow, increased right ventricular load, leading to right ventricular enlargement, pulmonary hypertension, and right heart failure. If the aortic sinus aneurysm ruptures into the right atrial cavity, the right atrial pressure increases significantly, causing marked right atrial enlargement and obstruction of superior and inferior vena cava blood return, resulting in symptoms of right heart failure. If the aortic sinus aneurysm ruptures into the pericardial cavity, it causes acute cardiac tamponade and death.

Aortic sinus aneurysms are often associated with other cardiac anomalies, the most common being ventricular septal defects (accounting for about 40–50%), which further increases the load on both ventricles. They may also be accompanied by aortic valve insufficiency, pulmonary stenosis, aortic coarctation, and patent ductus arteriosus.

The progression of the disease varies depending on the size of the rupture. The larger the rupture, the greater the left-to-right shunt, leading to earlier symptom onset and faster disease progression.

bubble_chart Clinical Manifestations

Unruptured aortic sinus aneurysms do not present clinical symptoms; symptoms only appear after rupture. The age of onset is mostly between 20 and 40 years old. About one-third of patients experience sudden onset, feeling severe pain in the precordial or epigastric region, chest tightness, and difficulty breathing during intense physical exertion, with symptoms resembling angina pectoris. In cases where the condition rapidly deteriorates, patients may die from right heart failure within a few days of onset. Most cases involve smaller ruptures, and after onset, there may be a remission period lasting weeks, months, or even years before symptoms of right heart failure appear. A small number of patients have very minor ruptures, with only a small left-to-right shunt, and may remain asymptomatic for a long time. These patients are often incidentally diagnosed due to heart murmurs and confirmed through echocardiography, right heart catheterization, and aortic angiography.

Physical examination: A significant drop in diastolic blood pressure, increased pulse pressure, water-hammer pulse, capillary pulsation, and femoral artery pistol-shot sounds. Cardiac examination reveals a thrill palpable at the third and fourth intercostal spaces along the left sternal border, where a typical to-and-fro or continuous rough murmur can be heard. The murmur resembles that of a patent ductus arteriosus but is located lower. In cases where the aortic sinus aneurysm ruptures into the right atrium, jugular vein distension is often observed. Electrocardiogram: Shows left ventricular hypertrophy or biventricular hypertrophy, myocardial damage, and right bundle branch block. Chest X-ray: Reveals significant cardiac enlargement, prominent pulmonary artery segments, pulmonary congestion, and increased lung markings. Echocardiography: Demonstrates mid-segment waveform of the aortic sinus wall, with the aortic sinus wall prolapsing into the right ventricular outflow tract during diastole. Right heart catheterization: Confirms increased oxygen saturation in the right atrium, right ventricle, or pulmonary artery, indicating a left-to-right shunt at these sites. Retrograde aortography: Clearly identifies the rupture site of the aortic sinus aneurysm and the cardiac chamber into which it has ruptured.

bubble_chart Diagnosis

The diagnosis of sinus of Valsalva aneurysm is generally not difficult to establish based on medical history, physical examination, and the presence of a continuous cardiac murmur, combined with X-ray and echocardiography. For cases where diagnosis is uncertain and differential diagnosis is required, right heart catheterization or retrograde aortography may be necessary.

bubble_chart Treatment Measures

The aortic sinus aneurysm gradually develops and expands after formation, ultimately leading to rupture. Therefore, all patients diagnosed with an aortic sinus aneurysm, whether ruptured or not, should undergo surgical resection. For acute ruptures, surgical treatment should be performed as early as possible after medical management improves heart failure. If heart failure remains uncontrolled, early surgery is even more critical. The surgery is performed under extracorporeal circulation combined with hypothermia and myocardial protection for direct visual repair. The patient is placed in a supine position with a median sternotomy incision. After longitudinally sawing the sternum and incising the pericardium, a distinct thrill can be palpated on the surface of the heart where the rupture enters. Intracardiac exploration may be performed if necessary.

The cardiac incision approach is determined by the chamber into which the aortic sinus aneurysm ruptures or any concomitant cardiac anomalies, and may involve the right atrium, right ventricle, or aorta (Figure 1). After incising the heart to expose the lesion, the aneurysm appears as a thin-walled, smooth sac with one or more perforations at the apex. The ruptured aneurysm has both internal and external openings, with the internal opening located at the aortic sinus. The aneurysm wall is longitudinally incised, and the entire sac is circumferentially excised approximately 0.3–0.4 cm from the internal opening, leaving the tougher surrounding tissue for suturing. Suturing begins with a continuous "8" stitch, followed by reinforced mattress sutures on both sides of the sac wall (Figure 1). Through the aortic incision approach, cardioplegic solution can be directly infused via the coronary artery orifice, and the valve leaflets can be precisely inspected. The saccular aneurysm can be retracted from the right atrium or right ventricle into the aorta, and the excess aneurysm wall is excised. The resection and suturing methods for the sinus aneurysm are the same as described above. For concomitant supracristal ventricular septal defects, repair can be performed via the aortic or right ventricular incision. If aortic valve insufficiency is present, aortic valve repair or aortic valve membrane replacement can be performed simultaneously.

(1) Rupture of the right coronary sinus aneurysm into the right ventricle

(2) Aortic root or right ventricular incision

(3) Suturing the rupture through the aorta after excising the sac

(4) Suturing the rupture through the right ventricle

(5) "8" stitch for the sac opening, with additional pledgeted mattress sutures if necessary

Figure 1: Repair of ruptured aortic sinus aneurysm via aortic or right ventricular incision.

bubble_chart Prognosis

The domestic surgical mortality rate is approximately 5-10%, with satisfactory long-term outcomes.

bubble_chart Differentiation

The following diseases should be differentiated from aortic sinus aneurysm:

(1) Patent ductus arteriosus and aortopulmonary septal defect. These congenital heart defects with left-to-right shunting in the aorta have no sudden onset history. The machinery-like continuous murmur is located at the left second intercostal space and often radiates to both lungs and the ipsilateral subclavian area. Echocardiography reveals a left-to-right shunt in the descending aorta and left pulmonary artery region. If necessary, right heart catheterization or retrograde aortography can confirm the diagnosis.

(2) Ventricular septal defect with aortic valve insufficiency. This condition has no sudden onset history. The to-and-fro murmur during systole and diastole is heard at the left second and third intercostal spaces. Echocardiography shows an absence of the ventricular septum echo segment and a left-to-right shunt within the ventricular cavity. The aortic valve may exhibit signs of valvular insufficiency.

(3) Coronary artery fistula. This refers to an abnormal communication between the left or right coronary artery and the cardiac chamber or coronary vein. A continuous murmur, predominantly during diastole, can be heard in the lower precordial area. Echocardiography or retrograde aortography reveals dilated and tortuous coronary arteries, as well as contrast medium flowing from the coronary artery into the cardiac chamber.