Infundibulum hypertrophic muscle bundle resection

Right ventricular funnel stenosis is a blood flow obstructive disease caused by muscle hypertrophy and fibroplasia in the right ventricle funnel. Simple funnel stenosis accounted for 1.3% to 2.7% of right ventricular outflow obstruction, and 15% to 20% of pulmonary stenosis cases may produce secondary muscle hypertrophy and cause funnel stenosis. There are two types of right ventricular funnel stenosis. The first type is localized stenosis. There is fibrous or fibromuscular annular stenosis in the funnel. The stenosis is limited. The stenosis and the pulmonary valve form different sizes. 3 heart chamber. The second type is a wide narrowing of the funnel, and the muscles are generally thickened and tubular, and progressively aggravated. The latter is more common. The main pulmonary artery expands without stenosis. In 1948, Brock inserted a small incision from the right ventricle to bite the edge of the narrow mouth of the funnel. After surgery, the symptoms were improved, but the narrowing of the funnel was not complete. In 1959, Swan blocked the vena cava blood flow under low temperature anesthesia to relieve the right ventricular stenosis. However, the safe operation time was only within 8 min. With the development of extracorporeal circulation technology, it provides safe and sufficient conditions for the perfection of right ventricular stenosis. Treatment of diseases: hypertrophic obstructive cardiomyopathy Indication 1. After the event, there are clinical manifestations such as shortness of breath, pain in the precordial area, right heart failure and cyanosis. 2. Right ventricular peak pressure >70 mmHg at rest; right ventricular-pulmonary pressure difference >50 mmHg. 3. Pulmonary valve orifice area <0.5cm2. 4. The right ventricular end diastolic blood pressure increased after exercise without obvious symptoms, and the cardiac output did not increase. Preoperative preparation In addition to the general routine preparation for open heart surgery before surgery, pay special attention to the following points: 1. Detailed examination before surgery, clear diagnosis by echocardiography, etc. to determine the surgical indications and programs. 2. In very severely stenotic neonates, prostaglandin E1 is administered after birth to delay arterial catheter closure, increase pulmonary blood flow, and improve hypoxia. Patients with obvious cyanosis should correct acidosis. 3. With severe heart failure, effective control of heart failure should be given to improve the safety of surgery. Surgical procedure 1. The chest midline incision. 2. Longitudinal cut happy packets, establish extracorporeal circulation, under the bypass of cardiopulmonary bypass, do right or lateral outflow oblique or longitudinal incision to avoid damage to the large coronary artery branches. However, a longitudinal incision should be used in patients with severe stenosis or suspected annulus stenosis, which may allow the right ventricular funnel to widen or the incision to extend upward across the pulmonary valve annulus widening. 3. Expose the fattening muscle bundle of the funnel, and use a knife to remove the thick fibrous septum, wall bundle and hypertrophic supraventricular iliac crest and hypertrophic muscle on the anterior wall of the funnel. 4. Surgery should be performed to detect the release of the right ventricular outflow tract stenosis, adult right ventricular outflow tract should be able to pass the index finger, children through the little finger. If the outflow tract is still stenosis or right ventricular systolic pressure / left ventricular systolic pressure > 0.65, right ventricular - pulmonary artery pressure difference > 30mmHg, you need to use autologous pericardial or non-leakage artificial blood vessels to widen the right ventricular outflow Road. If the pulmonary annulus is normal, the patch is confined to the right ventricular outflow tract. If the annulus is small, the patch should be widened across the annulus.