Pulmonary orifice stenosis is a congenital stenotic malformation that exists between the right ventricle and the pulmonary artery. There are three types: pulmonary stenosis, right ventricular funicular stenosis, and stenosis of the main pulmonary artery and its branches, with valvular stenosis being the most common. Valvular stenosis is usually a thickened junction of the valve leaflets, with a fish-mouth-like protrusion of the valve opening into the pulmonary artery and a post-stenotic dilatation of the main pulmonary artery trunk, often with varying degrees of pulmonary annular stenosis. Right ventricular funicular stenosis can be septal stenosis or tubular stenosis. Septal stenosis forms an annular fibrous septum inferior to the right ventricular funnel, which separates the right ventricle into two ventricular chambers of unequal size, with an enlarged thin-walled ventricular chamber above it called the third ventricle. Tubular stenosis is caused by a hypertrophied right ventricular anterior wall, supraventricular ridge, and abnormally thick septal and wall bundles. The pulmonary artery trunk and its branches may be stenosed or dysplastic in one or more annuli. Pathophysiology Pulmonary artery stenosis causes obstruction of blood drainage and increased pressure in the right ventricle. The pressure step difference between the right ventricle and the pulmonary artery depends on the degree of stenosis. A pressure step difference of <40 mmhg is considered mild stenosis, 40 mmhg-100 mmhg is considered moderate stenosis, and >100 mmHg is considered severe stenosis. Peripheral cyanosis may occur due to obstruction of venous return flow, reduced cardiac output, and blood stasis. In about 1/4 cases with patent foramen ovale or atrial septal defect, central cyanosis occurs when the right atrial pressure is significantly elevated and a right-to-left shunt occurs at the atrial level. Long-term increase in right ventricular load causes right ventricular centripetal hypertrophy, aggravates right ventricular outflow tract stenosis, and leads to heart failure and even death. Clinical presentation symptoms are related to the degree of stenosis, presence of patent foramen ovale, atrial septal defect, and secondary tricuspid regurgitation. Mild stenosis may be asymptomatic or mildly symptomatic. Common symptoms are palpitations, shortness of breath, chest tightness, and even syncope with slight activity, poor work tolerance, and easy fatigue. Symptoms worsen with age. In cases with coexisting foramen ovale, cyanosis may appear after activity. In severe cases, cyanosis may also occur at rest. In advanced patients, there are often signs of right heart failure such as jugular vein filling, hepatomegaly, swelling of the lower limbs, and even ascites. Physical examination: In pulmonary valve stenosis, a loud and rough systolic jet-like murmur can be heard between the second ribs at the left edge of the sternum and is transmitted to the upper left side. Most of them are accompanied by systolic tremor. The second pulmonary artery sound is diminished or absent. In right ventricular funnel stenosis, the systolic murmur is lower, and in some cases, the second pulmonary artery sound is normal; in patients with tricuspid valve insufficiency, a systolic murmur can be heard in the tricuspid auscultation area. Electrocardiogram: Depending on the degree of stenosis, it can show normal, right-sided electrical axis, right ventricular hypertrophy strain, T-wave inversion and P-wave hyperacusis. X-ray: the right ventricle and right atrium may be enlarged, and the pulmonary artery segment may be protruding. However, in cases of funnel stenosis, the protrusion of the pulmonary artery segment is not obvious. The two lung fields are clear and the vascular texture is reduced, especially in the lateral 1/3 of the lung field. Echocardiography: It can show the type and degree of stenosis. Pulmonary valve stenosis shows widening of the main pulmonary artery trunk, thickening of the valve leaflets, echogenic enhancement, restricted opening and thickening of the right ventricular wall. Color Doppler ultrasound shows a high-velocity flow signal at the stenotic valve and allows measurement of the maximum transvalvular pressure difference. Funnel stenosis shows a narrow right ventricular outflow tract with thickened trabeculae and muscle columns. Color Doppler ultrasound can measure turbulent flow signals in the right ventricular outflow tract. Diagnosis and differential diagnosis Diagnosis can be made based on clinical manifestations, combined with electrocardiography, chest x-ray, and echocardiography. If necessary, right ventricular manometry and angiography with cardiac catheterization can help to confirm the diagnosis. With the help of the characteristic murmur of pulmonary artery orifice stenosis, the features of diminished or absent second pulmonary artery sound, and its x-ray signs of pulmonary blood reduction, it is not difficult to differentiate from ventricular septal defect and atrial septal defect. In some cases of tetralogy of Fallot, right ventricular outflow tract obstruction is not obvious, and its manifestation is similar to pulmonary artery stenosis. Echocardiography and cardiac catheterization can indicate the presence of septal defect and aortic span, which can help in differential diagnosis. Surgery 1. Indications for surgery Mild stenosis, no obvious symptoms, no obvious changes in chest X-ray and electrocardiogram, and right ventricular systolic pressure <60 mmhg do not require surgery. Moderate stenosis with obvious clinical symptoms, electrocardiogram suggesting right ventricular hypertrophy or with strain, cardiac catheterization showing right ventricular pressure >75mmHg, and pressure step difference between right ventricle and pulmonary artery >50mmHg, are indications for surgery. In severe stenosis, the pathology progresses rapidly and the secondary right ventricular outflow tract obstruction will aggravate the stenosis, requiring early surgery. 2.Surgical methods Since the technique of extracorporeal circulation has become very mature and safe, several non-extracorporeal procedures that were used have been abandoned. A median sternal incision is made, and the cardiac incision is selected according to the type of stenosis under extracorporeal circulation with a beating or stopped heart. For pulmonary stenosis, the main pulmonary artery is usually dissected longitudinally and a valvular junctional dissection is performed under direct vision; for funicular stenosis, the anterior wall of the right ventricular outflow tract is dissected and the stenotic fibrous annulus or hypertrophic wall bundle and septal bundle are removed to unblock the right ventricular outflow tract. If the right ventricular outflow tract is still stenotic after evacuation, the outflow tract is widened with autologous pericardial slices or polyester woven slices. If annular stenosis is present, the right ventricular outflow tract is widened across the annulus by dissecting the annulus. In recent years, transcatheter balloon dilatation of the pulmonary valve has been used for valvular stenosis, which is more popular because it does not require a thoracotomy and has a rapid postoperative recovery. However, in some cases, the dilatation effect is not satisfactory and complications of pulmonary valve insufficiency can occur.