Surgical treatment of 125 cases with congenital diaphragmatic eventration in a single institution

Backgrounds This study sought to investigate the clinical characteristics of congenital diaphragmatic eventration (CDE) and to compare the ecacy of thoracoscopy and traditional open surgery in infants with congenital diaphragmatic eventration. Methods We retrospectively analyzed the clinical data of 125 children with CDE(90 boys, 35girls; median age:12.2 months, range 1h-7years;body weight1.99-28.5kg,median body weight 7.87±4.40kg) admitted to our hospital in recent 10years, and statistically analyzed their clinical manifestations and surgical methods. Results 108 children in this group underwent surgery, of which 67 underwent open surgery and 41 underwent thoracoscopic diaphragmatic plication.107 patients recovered well postoperatively, except for 1 patient died of respiratory distress after surgery.Followed up for 1-9.5 years,107 patients had signicantly improved preoperative symptoms.During follow-up, the location of the diaphragm was normal and no paradoxical movement was observed.Eleven of the 17 children who did not undergo surgical treatment did not see a decrease in diaphragm position after 1-6 years of follow-up.In the thoracoscopy group, the index data on the operation time, intraoperative blood loss, chest drainage time, postoperative mechanical ventilation time, postoperative hospital stay and postoperative CCU admission time were better than those in the open group.The difference between the two groups was statistically signicant (P (cid:0) 0.05). Conclusions Clinical symptoms of congenital diaphragmatic eventration varied in severity. Patients with severe symptoms should be operated.Both thoracoscopic diaphragmatic plication and traditional open surgery can effectively treat congenital diaphragmatic eventration,but compared with open surgery, thoracoscopic diaphragmatic plication has the advantages of short operation time, less trauma, rapid recovery, so it should be the rst choice for children with congenital diaphragmatic eventration.

Background CDE is considered to result from a congenital anomaly during the formation of the pleuroperitoneal membrane, as in Bochdalek diaphragmatic hernia, but occurring in a later stage during embryonal growth [1].CDE is a rare pathology occurs in 0.02 to 0.07/1,000 births affecting mostly males in 60 to 80% of cases.It accounts for 5%-7% of all diaphragm diseases [2].Because the infant ribs are horizontal and the intercostal muscles are weak, the breathing movement mainly depends on the abdominal breathing of the diaphragm muscles moving up and down.Infants and children with CDE have abnormally elevated diaphragm muscles, which often lead to collapse of the affected alveoli or atelectasis, affecting lung ventilation and lung development.Therefore, infants and children with CDE often have symptoms such as dyspnea, repeated respiratory infections, low weight, and stunting.Severe cases may manifest as respiratory distress syndrome, seriously affecting the quality of life of children.Traditionally, diaphragmatic plication has been performed by thoracotomy or laparotomy, particularly in symptomatic smaller children [3].However, advancements in endoscopic surgery have allowed diaphragmatic eventration to be treated quickly and safely. Here, we present our experience with different surgical procedures to treat 125 cases with CDE.

Material And Methods
We retrospectively analyzed the clinical data of 125 children with congenital diaphragmatic eventration admitted to the Department of Cardiothoracic Surgery, Children's Hospital of Chongqing Medical University from January 2010 to January 2020.Inclusion criteria:children with CDE have dyspnea, repeated respiratory tract infection and other symptoms.Chest X-ray, CT or gastrointestinal radiography clearly diagnose diaphragmatic eventration.Exclusion criteria:Exclude children with acquiring diaphragmatic eventration associated with surgery.
Open surgery group: thoracotomy for the right diaphragm eventration and laparotomy for the left diaphragm eventration.Through the thoracoabdominal approach, we remove the weak diaphragm and intermittently sew with non-absorbable sutures to ensure that the cut diaphragm into a shingled shape to strengthen the weak area of the diaphragm.Thoracoscopic group: using the three-hole method,5 mm thoracoscopy is placed on the lower edge of the scapula tip trocar, and two operation holes are made in the fourth intercostal space on both sides of the trocar.Continuous barbed sutures from the outside to the inside are utilized to make the diaphragm into a shingled shape to strengthen the diaphragm. See Figure   1 for details.

Statistical analyses
All the collected data were statistically analyzed using SPSS 22.0 software.The continuous variables were expressed as mean±standard deviation, and the classi cation variables were expressed as ratio columns. The comparison between the two groups was expressed by independent sample t-test, and the count data was expressed by Fisher's precision test. The difference was statistically signi cant with a p value of <0.05.

Results
The study included 125 children diagnosed with CDE.There were 90 males (72%) and 35 females (28%), aged 1h-7 years ,median age: 12.2 months,with body weight of 1.99-28.5kg(7.87±4.40 kg), 78 children (62.4%) on the right,47 children (37.6%) on the left, and no bilateral children. There were 79 children with malformations in this group, mainly including 19 cases of congenital heart disease,16 cases of congenital pulmonary dysplasia, 8 cases of pectus excavatum, 4 cases of hiatal hernia, and 3 cases of chicken breast.
The clinical symptoms of CDE were reported for 108 of 125 cases. The main symptoms of CDE in infants included the following:cough and asthma, dyspnea, recurrent respiratory tract infections, refuse milk and vomit, and arrhythmia.About 17 cases were found to asymptomatic or accidentally discovered on routine physical examination.The clinical symptoms of CDE are shown in table 1.All the 125 cases had positive manifestations on chest X-ray, among which 39 cases (31.2%) were diagnosed by combined chest CT, 32 cases (25.6%) were diagnosed by combined chest X-ray and digestive tract radiography, and 99 cases were found to have eventration of diaphragmatic shadow. All cases were con rmed as CDE after surgery, and the position of CDE was presented in table 2. 41 cases underwent transthoracic diaphragm plication and 26 cases underwent transabdominal diaphragm plication. Among them, 9 cases were diagnosed as CDE before operation. The stomach, duodenum, spleen and part of the liver herniated into the thoracic cavity during the operation. Diaphragmatic hernia was diagnosed after the operation.
We analyzed the data of the relevant surgical indicators of the two groups.In the thoracoscopy group, the index data on the operation time, intraoperative blood loss, chest drainage time, postoperative mechanical ventilation time, postoperative hospital stay and postoperative CCU admission time were better than those in the open group. The difference between the two groups was statistically signi cant (p<0.05).There was no statistically signi cant difference between the two groups in descending distance of diaphragm(P>0.05). See Table 3 for details.
Patients had been followed-up radiologically annually to demonstrate the position of the diaphragm,and symptoms if any were also evaluated. In open surgery group, 1 case died of respiratory distress after operation.Almost all respiratory and digestive symptoms disappeared within 1 month after the operation, and none had any symptom 3 years after surgery.Followed up for 1-9.5 years,107 patients had signi cantly improved preoperative symptoms.Eleven of the 17 children who did not undergo surgical treatment did not see a signi cant decrease in diaphragm position after 1-6 years of follow-up, and 6 patients were lost to follow-up.The comparison of chest radiographs before and after operation is shown in Figure 2. Discussion CDE is characterized by incomplete muscle regeneration.Subsequent abnormally elevated diaphragm muscles cause abnormal movement of the affected hemidiaphragm during respiration. It can occur locally or affect the entire diaphragm.In this study, there were 90 males (72%), 35 females (28%), 78 children (62.4%) on the right side, and 47 children (37.6%) on the left side. We observed that the incidence was higher in male children, and the incidence on the right side was higher than that on the left side.CDE can be associated with other developmental defects, and associated comorbidities include congenital hypoplastic lung, congenital heart disease, pectus excavatum,cleft palate, hypospadias, cryptorchidism, and congenital torticollis [4].77 patients in this group were combined with other malformations, congenital heart disease (19, 15.2%) and congenital hypoplastic lung (16, 12.8%) were the main relevant abnormalities in this study.The above facts is di cult to determine whether CDE is accompanied by other malformations or other malformations with this disease.Its numerous accompanying malformations suggest that the cause of the teratology is di cult to explain with a single etiology, and may be similar to the cause of other congenital malformations.
The main symptom of CDE is the compression of the lower lobe of the lungs due to the increase of intraabdominal organs. After compression, the mediastinum can also cause the mediastinum to move on the health side and reduce the health side lung function accordingly. In unilateral CDE, the lung capacity and total lung capacity is reduced by 20% -30% [5].Bilateral diaphragmatic eventration reduces the lung functions even more seriously, especially in the supine position [6].The treatment principle of CDE is to restore the normal anatomical position and tension of the diaphragm, the method is to strengthen the weak diaphragm,the goal is to maintain the normal volume of the lungs and the process of lung ventilation.Whether asymptomatic patients need surgical correction has been controversial for a long time.In this group of 17 children who did not undergo surgical treatment,11 patients received 1-6 years of follow-up and did not see decrease in diaphragm position. Therefore, we believe that symptomatic children need timely surgical treatment. Yazici M et al.'s study also considered symptomatic children, usually require surgery [7].Therefore, we believe that the indications for surgery are as follows: relative to the normal position,the diaphragm is displaced upwards by 3 intercostals and above. The diaphragm eventration caused obvious compression on the affected side of the lung, and obvious shortness of breath,asthma and other respiratory distress symptoms. Frequent lung infections, hypoxemia, and even abnormal breathing exercise. During the follow-up, the diaphragm continued to rise and the eventration was aggravated.
The traditional treatment method of CDE is diaphragmatic plication performed either by laparotomy or thoracotomy.However, with the development of minimally invasive technology, thoracoscopy is gradually applied in the treatment of CDE [8][9][10].We believe that children with right diaphragm eventration and intrapulmonary malformation need to be corrected through the thoracotomy approach as the rst choice, because it is not affected by the intestinal canal, full exposure, easy to operate, can see the phrenic nerve and reduce postoperative intestinal paralysis.The laparotomy is suitable for children with left diaphragmatic eventration, inability to distinguish between diaphragmatic eventration and diaphragmatic hernia, and considering gastrointestinal malformation.Because the left chest is the heart, there is a high risk of thoracotomy. The use of subcostal incision is conducive to the repair of the hernia and the discovery of possible intestinal malformations.However, in the open group, we used thoracotomy for 4 children with left side diaphragmatic eventration, and achieved satisfactory clinical results. Therefore, we believe that the choice of approach is mainly based on the characteristics of the patient's diaphragmatic disease and which approach the surgeon prefers Familiarity.The preoperative diagnosis of 9 children in this group was unknown, and diaphragmatic hernia and other gastrointestinal tract malformations were found during the operation, so the choice of preoperative approach was particularly important.We resect the weak diaphragm in the diaphragm via the thoracoabdominal route and sutured the diaphragm intermittently with non-absorbable sutures to make the cut diaphragm imbricate to strengthen the weak area of the diaphragm.The advantage of this technique is that it increases the tension of the diaphragm to evenly distribute the tension throughout the repair area.
With the development of minimally invasive technology, thoracoscopy is gradually used in the treatment of CDE.We compared the effect of open surgery and thoracoscopy in the treatment of CDE in children.The operation time, chest drainage time, postoperative mechanical ventilation time, postoperative hospital stay and postoperative CCU admission time in the thoracoscopy group were shorter than those in the open group, and the difference between the two groups was statistically signi cant (P<0.05). We consider the possible reasons as follows: Thoracoscopic surgery adopts three hole method, which is less traumatic and less prone to bleeding. The recovery of children is faster after operation. The technique of thoracoscopy is skilled, and the operator and assistant cooperate with each other. We used barbed wire to sew continuously without knot, which greatly shortens the operation time and is obviously better than the open surgery.
In this group of 41 children without other thoracoabdominal malformations that need to be corrected, we used thoracoscopic diaphragm plication.Various techniques of diaphragmatic plication have also been employed. All techniques aim to reduce the abundant diaphragmatic surface and lower the diaphragmatic dome.Various suturing methods have been used, including interrupted horizontal mattress sutures, multiple parallel U sutures, gure of eight sutures, continuous running sutures, and endostaplers. Various non absorbable but also absorbable sutures have been used. We used barbed wire to suture the diaphragm from the outside to the inside in a continuous imbricated fashion to strengthen the diaphragm.Combined with the literature and our experience, compared with ordinary absorbable suture, continuous suture of the diaphragm with barbed wire has the following advantages: Starting from the second stitch, it is not easy to slip after tightening the suture.One stitch is sewn to tighten one stitch, and no knot is needed during the suture process,which greatly shortens the operation time. The diaphragms were sutured continuously by barbed wire to make the diaphragms stretch evenly from the center to all directions, and the tension distribution was uniform, so that the movement of the diaphragms was more coherent, and the diaphragms would not be ischemic due to over tight suturing, nor would the suture relax to cause recurrence. The barbed wires suture is close, less bleeding, wireless knot, absorbable, wireless knot reaction and residual suture. There is a view that continuous suture may compromise the safety of the suture and the loosening of the knot may affect the folding of the entire diaphragm, but there is no evidence to support this view [11].A. Parlak, et al., and others adopted doublepurse suture method to strengthen the diaphragm, achieving better clinical effect [12].The usual advantages of thoracoscopy, such as reduced postoperative pain, satisfactory appearance and rapid recovery, are also applicable to our surgery, and should be the preferred treatment for CDE.  Figure 1