bubble_chart Overview

The patent ductus arteriosus is an important circulatory pathway during the fetal period. However, it should close automatically after birth (usually within 2–3 weeks). If it remains open after birth, a left-to-right shunt will occur at the pulmonary artery level, leading to a series of pathophysiological changes in the heart and circulatory system, clinically referred to as patent ductus arteriosus.

Patent ductus arteriosus can exist alone or in combination with other malformations. It is one of the common congenital heart diseases, occurring more frequently in males than females, with a ratio of approximately 3:1. Diagnosis of patent ductus arteriosus is generally straightforward, and surgical treatment is highly effective, with early surgery allowing complete restoration of normal cardiac function. The mortality rate is extremely low, and surgical intervention is recommended once diagnosed, with the ideal surgical age being 3–7 years. If treatment is delayed, the condition may progressively worsen, developing into severe pulmonary hypertension or even a right-to-left shunt, resulting in the loss of surgical opportunities. Clinically, this can lead to cyanosis, heart failure, and even death.

bubble_chart Clinical Manifestations

1. Small patent ducts may be asymptomatic; those with large ducts may experience palpitation and panting after exertion, chest tightness, lack of strength, and in severe cases, symptoms of left heart failure. When pulmonary hypertension occurs, hemoptysis or cyanosis may be present.
2. A tremor can be palpated at the second intercostal space on the left sternal border, accompanied by a rough continuous machinery-like murmur, accentuated P2, widened pulse pressure, enhanced neck vessel pulsations, and bounding pulses and pistol-shot sounds detectable in the limbs. In cases of severe pulmonary hypertension, the continuous murmur may disappear, leaving only a systolic murmur.

bubble_chart Diagnosis

1. Small patent ducts may be asymptomatic, while those with large ducts are prone to common colds and recurrent pneumonia. There may be palpitations, panting, chest tightness, and lack of strength after exertion. In severe cases, symptoms of left heart failure may occur. Severe pulmonary hypertension can lead to hemoptysis or cyanosis.
2. A tremor may be palpated in the second left intercostal space, accompanied by a rough, machinery-like continuous murmur. P2 is accentuated, pulse pressure is widened, and carotid pulsations are enhanced. Peripheral vessels may exhibit water-hammer pulses and pistol-shot sounds. In cases of severe pulmonary hypertension, the continuous murmur disappears, leaving only a systolic murmur.
3. Electrocardiogram: Normal or showing left ventricular high voltage or left ventricular hypertrophy.
4. X-ray: The left heart border extends downward and to the left, with a widened main pulmonary artery that may appear funnel-shaped. The pulmonary artery segment is prominent, hilar vascular shadows are intensified, and pulmonary blood flow is increased.
5. Color Doppler echocardiography: A blood flow channel can be observed between the bifurcation of the left and right pulmonary arteries and the descending aorta.
6. Right heart catheterization: Oxygen content in the pulmonary artery exceeds that of the right ventricle by 0.5ml%. Pulmonary artery pressure and resistance are elevated to varying degrees, and the catheter can pass from the pulmonary artery through the duct to the descending aorta.
7. Retrograde ascending aortography: The pulmonary artery and aorta are visualized simultaneously, and the patent duct can be seen.

bubble_chart Treatment Measures

Patent ductus arteriosus (PDA) is a congenital malformation, and a typical heart murmur along with ultrasound can confirm the diagnosis. Once diagnosed, surgical treatment should be performed as soon as possible to ligate the unclosed patent ductus arteriosus, which can cure the disease.

1. Children over one year old should undergo surgery once diagnosed. The ideal age for surgery is between 3 to 7 years. Infants under one year should only be considered for surgery if heart failure occurs. Adult cases can be treated surgically as long as secondary pulmonary vascular changes are reversible and left-to-right shunting predominates.
2. Severe pulmonary hypertension with irreversible pulmonary vascular changes and predominant right-to-left shunting are contraindications for surgery.
3. If PDA coexists with other cardiovascular malformations, such as tetralogy of Fallot or interrupted aortic arch, and the PDA serves a compensatory role, it should not be closed separately before definitive corrective surgery.
4. For isolated PDA, surgery is performed under general anesthesia at normal temperature via a left posterolateral incision, entering the chest through the 3rd or 4th intercostal space to ligate or divide and suture the ductus.
5. For older patients with severe pulmonary hypertension or concurrent intracardiac malformations, surgery is performed under general anesthesia with hypothermic cardiopulmonary bypass (via a median sternotomy) to ligate the ductus, perform intrapulmonary suture, or close the ductus with a patch.

bubble_chart Cure Criteria

1. Cure: Postoperative symptoms disappear, with no residual shunt or significant complications, and normal activities are unrestricted.
2. Improvement: In cases complicated by pulmonary hypertension, symptoms are alleviated after medical treatment and/or surgical ligation or division of the duct, but palpitations and shortness of breath may still persist.
3. No improvement: Symptoms show no significant relief, and residual shunt remains.