In most cases, the sternum starts from the level of the second or third rib cartilage backward to a point slightly above the saber process as the lowest point, and then returns forward to form a boat-like deformity. On both sides or laterally, the deformation is concave inward, forming the two walls of the funnel chest. In funnel chest, the rib alignment is more oblique than normal, and the ribs are depressed sharply from the top to the bottom, so that the front and back become closer, and in severe cases, the deepest depression of the sternum can reach the spine. Causes of funnel chest Some people believe that funnel chest is related to calcium deficiency in early childhood, which is incorrect. The cause of funnel chest is not well understood, and some patients have a family history. The incidence of funnel chest in patients with a family history is 2,5 per 1,000, while in those without a family history, the incidence of funnel chest is only 1,0 per 1,000. The heritability of funnel chest was studied in patients with a family history from the perspective of genetic disease. In the United States, 34 families with a family history were studied. 24 families were analyzed by genealogical analysis and chromosome analysis in cells, 14 of which were autosomal dominant; 4 families were autosomal recessive; and 6 families were sex-linked (X-linked) recessive. Thus, for those with a family history, funnel chest is actually a congenital genetic disorder. Most people believe that funnel chest is a deformity due to overdevelopment of the rib cartilage and ribs in the lower chest and compensatory backward displacement of the sternum. Symptoms of funnel chest Funnel chest is mostly seen in children under the age of 15, and rarely seen in patients over the age of 40, probably because funnel chest and scoliosis compress the heart and lungs and impair respiratory and circulatory functions, resulting in shorter survival time and death before the age of 40. A mild funnel chest can be asymptomatic, while a more severe deformity compresses the heart and lungs, affecting respiratory and circulatory functions, reducing lung capacity, increasing functional residual air volume, and reducing activity tolerance. Young children often have recurrent respiratory infections with cough and fever and are often diagnosed with bronchitis or bronchial wheeze. Young children have fewer circulatory symptoms, while older ones can present with dyspnea, rapid pulse, palpitations, and even pain in the precordial region after activity. The main country is because the heart is compressed, the cardiac blood output cannot meet the needs during exercise, and the myocardium is hypoxic, thus causing pain. Some patients can also develop arrhythmias, as well as systolic murmurs. The less severe symptoms of compression of the funnel chest in infancy often go unnoticed. Some have inspiratory stridor and sternal aspiration depression, but the cause of the airway obstruction is often not detected. Children are often thin, immobile, prone to upper respiratory tract infections, and have limited mobility. Exertional expiratory volume and maximum ventilation volume are significantly reduced. The child may experience panic, shortness of breath and dyspnea during activity. In addition to the thoracic deformity, there are often special body shapes such as mild hunchback and abdominal protrusion. In most cases, the sternum of funnel chest starts from the level of the second or third rib cartilage backward to the lowest point a little above the glabella, and then returns forward to form a boat-like deformity. On both sides or laterally, the deformation is concave inward, forming the two walls of the funnel chest. In funnel chest, the rib alignment slope is larger than normal, and the ribs are depressed sharply from the top to the bottom, making the front and back closer, and in severe cases, the deepest depression of the sternum can reach the spinal surgery. In young patients with funnel chest, the deformity is often symmetrical, but with age, the deformity gradually becomes asymmetrical, the sternum tends to rotate to the right, the depression of the right rib cartilage tends to be deeper than the left, and the right breast development is worse than the left. The posterior chest is mostly flat-backed or round-backed, and scoliosis gradually worsens with age; scoliosis is less likely to occur when the patient is younger, and is more pronounced after puberty. The funnel chest deformity compresses the heart and lungs, and the heart is mostly displaced to the left side of the chest. Children often present with a distinctive frail posture: forward neck, rounded cut shoulders, and a cannulated abdomen. Funnel chest is sometimes combined with pulmonary hypoplasia, Marfan syndrome, and asthma, and the combined presence of these conditions often becomes an intolerable deformity for the patient, often requiring early surgical correction. Examination and diagnosis of funnel chest Funnel chest is very easy to diagnose clinically and the deformity is readily apparent. X-rays show a flat posterior portion of the rib cage with a sharp anterior and inferior decline, and the heart shadow is mostly displaced to the left side of the chest. There is a distinct radiolucent translucent area in the middle of the cardiac shadow, and the right cardiac margin often overlaps the spine. In individual patients with severe disease, the heart shadow can be located completely in the left thoracic cavity, and older patients have more scoliosis of the spine. In lateral chest radiographs, the sternal body can be seen to bend backward significantly, and in some cases the lower end of the sternum can reach the anterior edge of the spine. Posteroanterior photograph: transparent area in the cardiac shadow of funnel chest. Chest CT films can more clearly show the severity of the thoracic deformity and the degree of cardiac compression and displacement. The ECG may show inverted or bidirectional P waves of V1. There can also be right bundle branch conduction block, and cardiac catheterization can be traced to diastolic slopes and plateaus, the same as seen in constrictive pericarditis. Cardiac angiography shows right heart compressional malformations and right ventricular outflow tract obstruction. Funnel chest is very easy to diagnose clinically and the malformation is readily apparent. However, it is difficult to determine the severity of the funnel chest, and there are many ways to describe it clinically. It uses light source and lattice projection method to take pictures of the corrugated contour image of the depressed part of the chest wall, and input the volume of the depressed part into the electronic computer by digital converter based on the interval and number of corrugated contour lines to determine the severity of the funnel deformity and to evaluate the effect of surgical treatment. 2.Funnel index (FI) is another way to express the deformity. FI=a×b×cA×B×Ca, the longitudinal diameter of the depressed part of the funnel chest; b, the transverse diameter of the depressed part; c, the depth of the depressed part; A, the length of the sternum; B, the transverse diameter of the thorax; C, the shortest distance from the angle of the pectoral muscle to the vertebrae The criteria for determining the degree of depression of the funnel chest are: severe: FI>0,3, moderate 0,3>FI>0,2 The light degree: FI <0, 2. 3, the funnel part of the water injection to measure the amount of water so that patients lying on their backs, in the funnel part of the water injection and then measure the amount of water, you can also understand the severity of the funnel chest, severe funnel chest of water capacity up to about 200ml. The volume of the funnel chest depression can be easily measured by filling the funnel chest with play dough, removing the play dough after shaping and immersing it in water. x-ray examination shows that the posterior part of the rib cage is flat and the anterior part is sharply tilted downward, the heart shadow is mostly displaced to the left side of the chest cavity, there is an obvious radiolucent area in the middle of the heart shadow, the right heart margin often overlaps with the spine, and the heart shadow can be completely located in the left side of the chest cavity in individual severe patients. The right heart margin often overlaps with the spine, and in some severe cases, the heart shadow can be completely located in the left side of the chest cavity. Lateral chest radiographs can show that the sternal body is obviously bent backward, and in some cases the lower end of the sternum can reach the anterior edge of the spine. CT films of the chest can more clearly show the severity of the thoracic deformity and the degree of cardiac compression and displacement. The ECG may show inverted or bidirectional P waves in V1, or there may be right bundle branch conduction block. Cardiac catheterization may be traced to diastolic slopes and plateaus, the same as seen in constrictive pericarditis, and cardiovascular angiography shows right heart compression malformation and right ventricular outflow tract obstruction. Complications of funnel chest If the thoracic deformity caused by funnel chest is serious, the heart and lungs of the organs in the thoracic cavity are compressed to varying degrees, even causing heart displacement, and pulmonary ventilation is also affected, and if it develops further, serious diseases such as respiratory tract infections may occur. Sometimes it will be combined with pulmonary hypoplasia, Marfan syndrome, asthma and other diseases.