Neonatal congenital diaphragmatic hernia (CDH) is due to incomplete closure of the diaphragm during embryonic period, to unilateral or bilateral diaphragmatic defects, part of the abdominal organs through the defect into the thoracic cavity, resulting in anatomical relationship abnormalities of a disease, divided into thoracic-abdominal hiatus hernia, esophageal hiatus hernia, and congenital retrosternal hernia. (A) Pathogenesis: Partial defect of diaphragm in embryonic development is the basis for the development of CDH. The peripheral attachment site of the diaphragm is divided into 3 parts, i.e., the sternal part, the rib part and the spinal part. Diaphragmatic hernia occurs in 3 places: 1, thoracoabdominal fissure (Bochdalek’s hole): there is a small triangular gap between the posterior edge of the bilateral ribs and the outer edge of the lumbar costal arches, called thoracoabdominal fissure (Bochdalek’s hole), where a posterior lateral hernia, i.e., thoraco-abdominal fissure hernia or Bochdalek’s hernia, can be formed. In congenital diaphragmatic hernia, 85% to 90% are thoracoabdominal hiatal hernias, of which the left side accounts for 80%, the right side accounts for 15%, and less than 5% are bilateral. The incidence rate is 1:10,000 to 1:3,000, with males slightly outnumbering females. 28% to 31% of these cases are associated with malformations, with malformations of the cardiovascular system being the most common, and respiratory distress being the main symptom, and this is the most common type of symptomatic cases that occur in the neonatal period. With the development of medicine, the concept of treatment has been significantly improved, and the efficacy of treatment has been improved. 2, sternal hernia or Morgagni hernia: the lateral edge of the sternum and the medial edge of the bilateral ribs between the formation of a small triangular gap, known as the Morgagni hole, normally filled with connective tissue, the occurrence of diaphragmatic hernia in this hole is called the sternal hernia or Morgagni hernia. It is relatively rare in clinical practice. 3, esophageal hiatal hernia: esophageal hiatus is pike-shaped, peripheral and esophageal wall has a tough connective tissue connection between the anterior and posterior walls of the connection is tight and the two sides of the weaker, such as defects, called esophageal hiatal hernia. CDH incidence, especially in children without accurate statistics. In the past, it has been thought to be more common in Europe and less common in North America. With the domestic and foreign due to the improvement of detection technology, especially with the availability of pediatric professional X-ray physician, so that the CDH year by year, CDH in China is not rare. (B) pathogenesis Generally in the 10th week of gestation when the midgut returns to the abdominal cavity through the base of the umbilical cord, due to the presence of thoracoabdominal fissure, intestinal tubes can enter the thoracic cavity through the thoracoabdominal fissure, and even defects in the Dalian stomach, spleen, colon, and the left lobe of the liver are all brought into the thoracic cavity together. Pulmonary dysplasia is closely related to diaphragmatic hernia, and the severity of pulmonary dysplasia is related to the time and degree of visceral hernia formation. The clinical manifestations are related to the surface area of the involved alveolar and pulmonary arterial vascular beds and to the presence of other malformations. In autopsies of stillborn children with congenital diaphragmatic hernia, 95% were found to have other defects, and many deaths occurred in association with these malformations. About 25% of diaphragmatic hernias are associated with intestinal malrotation. 10% to 20% of diaphragmatic hernias are associated with a hernia sac. Various degrees of pulmonary dysplasia is due to visceral embedded bronchial growth stagnation, the number of reduction in the total number of alveoli, the total number of branches of the pulmonary artery is also reduced, and the thickening of the pulmonary arterioles, increased resistance, resulting in neonatal pulmonary hypertension, pulmonary hypertension leads to the oval foramen and the unclosed arterial ducts of the right-to-left shunt, the emergence of hypoxemia and hypercarbia, and thus prompted by the spasm of pulmonary vasculature, the formation of vicious circle, clinically known as persistent pulmonary hypertension in newborns (persistent pulmonary hypertension). It is called persistent pulmonary hypertension of the newborn (PPHN). (C) Symptoms and signs 1. Thoracoabdominal hiatal hernia: the main clinical manifestations in the neonatal period are acute symptoms of respiratory, circulatory and gastrointestinal systems at the same time, but the respiratory symptoms are the prominent manifestation. (1) Symptoms: Dyspnea, shortness of breath, cyanosis and other symptoms may begin to appear after birth or appear within a few hours after birth. Their severity depends on the size of the diaphragmatic defect, the amount of abdominal organs entering the thoracic cavity, and the status of pulmonary dysplasia. Dyspnea and cyanosis may be paroxysmal and variable, i.e., aggravated by crying or eating, or they may worsen suddenly and progressively. When crying and breathing hard, the affected side of the thoracic cavity generates great negative pressure, which incorporates abdominal organs into the thoracic cavity, causing severe dyspnea and immediate death if not treated in time or improperly. The entry of abdominal organs into the thoracic cavity not only compresses the lungs, but also distorts the pulmonary artery, thickens the arterial wall, and reduces the cross-sectional area of the vascular bed. As a result, persistent pulmonary hypertension is produced, and in addition to cyanosis, there are a series of symptoms such as shortness of breath, acidemia, hypoxemia, hypothermia, hypocalcemia, hypomagnesium, and so on. Vomiting symptoms are relatively rare in the clinic, and vomiting occurs only when thoracoabdominal hiatal hernia with poor intestinal rotation or herniation into the abdominal cavity organ incarceration causing intestinal obstruction. (2) Physical signs: the affected side of the thorax respiratory movement is weakened, fullness, widening of the rib gap, the heart is shifted to the healthy side, sometimes misdiagnosed as the right heart. Thoracic cavity percussion is turbid or drum sound, often turbid and drum sound. This is related to the nature of the herniated thoracic organ or the degree of intestinal insufflation. On auscultation, breath sounds on the affected side are diminished or absent, and bowel sounds can often be detected, which is important in the diagnosis of congenital diaphragmatic hernia. Newborns diaphragm position is low, often up to the level of the 8th to 9th thoracic vertebrae, the diaphragm and the chest and abdominal wall is weak, it is easy to transmit intestinal sounds to the chest, so it should be repeatedly examined and analyzed for diagnostic significance. The abdomen is sunken like a boat-shaped abdomen, because the abdominal organs herniated into the thoracic cavity becomes empty, if the hernia into the organs less, then the sunken is not obvious. 2, esophageal hiatal hernia: pediatric esophageal hiatal hernia is common in infants and young children, the clinical manifestations of diverse, and can not recount the history of the disease, there is no typical clinical symptoms, if the parents are not careful observation, often delayed diagnosis and treatment. Common clinical manifestations are as follows: (1) vomiting: full-term newborns, infants and young children and older children are the most common symptoms, accounting for more than 80% to 95%, can occur in the first week after birth. Vomiting in various forms, often in the lying position or at night, sometimes mildly showing milk spillage, severe projectile vomiting. The vomit is initially gastric, but in severe cases it is accompanied by bile, often due to reflux esophagitis of the lower esophagus. Vomiting of coffee-like fluid or vomiting of blood occurs, but in small amounts. If you can often maintain a semi-sitting position or feeding in the middle, viscous diet, vomiting significantly improved, 8 to 9 months after the disease, the number of vomiting is reduced, it may be the improvement of the disease, but also may be the formation of scarring stenosis of the lower esophageal fibrosis. (2) Vomiting blood, blood in stool: in addition to vomiting coffee-like material, children with severe vomiting also have vomiting blood, tarry stools and black stools, and most of the fecal laboratory tests are often positive for occult blood. Prolonged vomiting of blood and blood in the stools is due to reflux esophagitis, and inadequate nutritional intake results in anemic appearance, with hemoglobin often ranging from 80 to 100 g/L. The child’s length and weight are often lower than those of the same age. Their length and weight are often lower than those of children of the same age, resulting in poor growth and development. (3) Coughing, shortness of breath and other respiratory tract infection symptoms: As gastroesophageal reflux occurs at night, it often leads to aspiration. Repeated symptoms of respiratory tract infection. There are 30% to 75% of infants and childhood hiatal hernia of the esophagus is to repeated respiratory tract infections as the main complaint to the clinic, although the anti-inflammatory treatment, respiratory tract infection can be improved, but can not be cured. The reason is that some children with hiatal hernia have repeated respiratory infections due to the inhalation of a very small amount of gastric contents, which is usually unnoticeable, into the trachea. In some allergic children, a small amount of stomach contents is mistakenly inhaled into the trachea, resulting in allergic asthma-like attacks. (4) Dysphagia: the reflux esophagitis of sliding hiatal hernia gradually aggravates, and the inflammation has invaded the muscular layer, making the lower esophagus fibrotic, which not only results in esophageal shortening, cardia and gastric fundus herniated into the thoracic cavity, but also esophageal stenosis. Difficulty in swallowing often occurs, which can be improved by fasting and anti-inflammatory treatment in the early stage, but in the late stage, the patient cannot eat or vomit white mucus. (5) Paraesophageal hernia: sometimes the combination of the esophagus and the stomach is still in the normal position in the abdominal cavity, and there is a part of the fundus of the stomach herniated into the thoracic cavity or torsion herniated to the right side of the diaphragm. Poor gastric emptying causes retention gastritis, ulceration, bleeding. Torsion is prolonged and incarceration occurs. Obstructive symptoms occur with retrosternal pain, chest tightness, and shortness of breath. (6) Physical examination: poor development and nutritional status of the child, anemia appearance, general examination without positive signs, only the huge esophageal hiatal hernia occurs incarcerated or gastric torsion, the epigastrium can appear peritonitis symptoms, pulmonary respiratory tone is weakened. 3, congenital retrosternal hernia: parasternal hernia has no specific clinical symptoms, usually with the child crying, supine position, abdominal pressure increases, paroxysmal dyspnea, shortness of breath, cyanosis and other phenomena. These symptoms disappear or decrease when the child is in the upright position, quiet, and the abdominal pressure decreases. If the digestive tract herniated into the thoracic cavity becomes incarcerated, signs of intestinal obstruction such as vomiting, abdominal distension, and cessation of defecation occur. Sometimes bleeding from the digestive tract occurs, resulting in signs of anemia, and there is often epigastric discomfort when the colon is herniated into the thoracic cavity. (D) Diagnostic basis 1, prenatal diagnosis: fetal maternal amniotic fluid, amniotic fluid test can be found in lecithin and neurosphingolipid lower than normal. Doing ultrasonography can see abdominal organs in the fetal thorax. An intrauterine diagnosis can be made when amniocentesis imaging sees contrast in the fetal thoracic cavity. The time of prenatal diagnosis is related to the prognosis, the earlier the time, the worse the prognosis, and the prognosis of those diagnosed at more than 25 weeks is good. 2, congenital diaphragmatic hernia diagnosis: newborns after birth have obvious hypoxia, dyspnea, the affected side of the chest to hear the bowel sounds, the heart boundary shifted to the healthy side, should first consider the possibility of congenital diaphragmatic hernia. 3, auxiliary examination to confirm the diagnosis: X-ray radiography often has a side of the diaphragm outline is unclear, the thoracic cavity to see intestinal tubes or gastric vesicles due to inflation irregular translucent area or liquid surface. Parastomal hernia is commonly seen in the right anterior diaphragmatic angle area with a downward elevation, clear edges of the dense shadow, the center may contain gas. Right posterior lateral hernias are often atypical, and a rising or substantial shadow of the liver can be misdiagnosed as a tumor. To make the diagnosis more definitive, a gastric tube or oral contrast can be placed, and the diagnosis is established if a gastric tube or contrast is seen on the affected side of the chest. Barium examination is forbidden for newborns, and CT examination can be done if the diagnosis is difficult. (E) Differential diagnosis In differential diagnosis, it needs to be distinguished from diaphragmatic expansion, congenital cystic alveolar disease, congenital heart disease, pleural effusion and lung inflammation. Special mention should be made of congenital diaphragmatic expansion, which is caused by the absence of the muscle layer and collagen fiber layer of the diaphragm, the diaphragm becomes a translucent thin membrane composed of the peritoneum, the clinical manifestations can also appear dyspnea, and sometimes it is difficult to distinguish from diaphragmatic hernia on the X-ray chest and abdomen upright radiographs, but in the observation of respiratory motion and the diaphragmatic movement under the X-ray screen noted that diaphragmatic motion can often be abnormal diaphragmatic movement; that is, the diaphragm falls in the normal inhalation, and the diaphragm in the diaphragmatic expansion of the affected side of the diaphragm on the other hand, the diaphragm can be differentiated from the diaphragm. The diaphragm on the affected side rises, and the diaphragm on the affected side falls during exhalation. (F) Complications Complications of respiratory distress, metabolic acidosis, hypoxemia, hypercapnia, gastroesophageal reflux, intestinal obstruction, and even shock. It may also be complicated by scarring stenosis of the lower esophagus, anemia, nutritional deficiencies, growth and developmental disorders, and recurrent respiratory tract infections. Preventive methods (7) therapeutic measures 1, internal medicine treatment Diagnosis of diaphragmatic hernia in the fetal period: obstetric ultrasonography experts and fetal echocardiography experts should check whether there are other malformations and cardiac abnormalities, and whether there is a combination of chromosomal anomalies, in particular, trisomy 18-trimester syndrome. It must be discussed by perinatal medicine experts to decide whether to interrupt pregnancy, fetal surgery or wait until after birth. For those who use conservative treatment: dietary modification, appropriate use of viscous diet, life guidance for the sick child to use more semi-sitting position, appropriate patting of the back after eating. Gastric power drugs and acid-control drugs are given to strengthen gastric emptying and prevent the occurrence of esophagitis. 2.Surgical treatment: after the diagnosis is confirmed, elective surgery should be performed as early as possible, and emergency surgery if there is incarceration or closure. But generally need to be based on clinical symptoms, laboratory tests for assessment and preoperative preparation. The cause of neonatal diaphragmatic hernia dyspnea is due to pulmonary compression, and oxygen should be given immediately along with gastrointestinal decompression to improve respiration by reducing intrathoracic pressure. If PaCO 2 >60mmHg, PaO 2 7, PaCO 2 60% humidity warming box care, gastrointestinal decompression until the recovery of intestinal function; adequate nebulization, sputum suction and back patting in order to prevent pulmonary atelectasis and lung infection, postoperative ventilator continued application of the respiratory machine is very necessary for those who have respiratory distress, a little longer pressure support is conducive to the expansion of compressed and underdeveloped lung lobes. Congenital pulmonary hypoplasia and pulmonary hypertension are the most important causes of death in diaphragmatic hernia. Preoperative and postoperative pulmonary vasodilators, such as prostaglandin E 1 or inhaled NO, can be used. Membrane lung respiratory support has been reported to gain time for lung maturation, thus saving the life of critically ill children. The treatment of esophageal hiatal hernia is based on the size of the esophageal hiatus, the amount of herniation of the abdominal esophagus and cardia into the thoracic cavity, the combination of gastroesophageal reflux and gastric torsion, and the severity of the clinical symptoms. There is no clear line between surgery and conservative treatment. (1)Sliding small esophageal hiatal hernia: the clinical symptoms are mild, and can disappear or improve on their own during development, so conservative treatment is mostly used. (2)Huge type or with gastric torsion should be aggressively treated with surgery. (3) Medium-sized hernia can be treated with elective surgery according to the development trend of the disease and the actual situation of the child. (4) Small hernia is the same as sliding columnar hernia, using conservative treatment, and regular barium meal fluoroscopy, observation of hernia shape changes, if the 24h pH monitoring ≤ 4, esophagoscopy examination of inflammation is more serious, the pressure of the high pressure band at the lower end of the esophagus is significantly lower than the gastric pressure, and clinically obvious vomiting, and then consider surgery. (H) Prognosis The overall survival rate of children with congenital diaphragmatic hernia who become symptomatic within hours of birth is less than 50%. In a few medical centers around the world, the survival rate has improved to 60%-80% with the use of ECMO therapy. Children who survive neonatal surgery often have normal growth and development. There are different opinions on the development and function of the lungs after repair surgery, and the observations of Reid (1976) and others confirmed a decrease in both total and effective lung volumes and an increase in residual volume. Chatrath (1977) concluded that the volume of both lungs was normal, with a decrease in forceful expiratory volume in the first second (FEV1) only.In 1979, Boles concluded that all the investigations after CDH could be similar to those of normal children of the same age in a followup of 58 cases.In 1987, Xinhua Hospital of the Second Medical University in Shanghai followed up 20 cases of children (>80%) from 1 to 11 years after repair in terms of height, weight, growth, diaphragmatic activity, and function. Most of the children (>80%) were close to or the same as normal children in height, weight, development, diaphragmatic mobility, and pulmonary function measurements, especially the pulmonary oxygen consumption fraction. However, it has recently been reported in the literature that some of those with significant prolonged pulmonary insufficiency treated with ECMO may require lung transplantation despite later survival.