Discussion
Nowadays, most CPAMs are diagnosed prenatally, with an 85.7% prenatal diagnosis ate for CPAM15.The exact etiology and pathogenesis of CPAM are still unclear, and current studies suggest that some potential genes and expressions are related to the formation of lung cysts. The difference of Thyroid Transcription Factor 1, Fibroblast Growth Factor 7, Fibroblast Growth Factor 9, Clara cell marker 10, SOX 2, SOX10, COL2A1, Hoxb-5, hMSH-2 and other transcription factors and expression appear to play a role in the pathogenesis of CPAM16, 17.In addition, the positive rate of Transcription Factor 1 in CPAM type I, II, and III is significantly different, and it can be used as an important marker for CPAM tissue typing18.In severe cases, the lesion continues to grow and ultimately may cause severe lung compression, mediastinal shift, hydrops fetalis, and/or fetal demise. Management options include observation, maternal antenatal steroid administration, and fetal surgical intervention19, 20{Aziz, 2021 #37;Loh, 2012 #38;Aziz, 2021 #35}.In children with symptoms after birth, it is recommended to surgically remove the lesions as soon as possible. For asymptomatic children with prenatal diagnosis of CPAM, most experts still recommend early elective surgery, but the exact timing of surgery is still controversial. Early surgical resection can help early compensatory growth of the lung and reduce the possibility of repeated infection and malignant transformation21, but some doctors are concerned about the increased risk of surgical complications and anesthesia sequelae in children8, 22.Therefore, exploring the optimal timing of early surgery, that is, exploring the timing of compensatory lung growth and reduction of lung-related diseases in children with good tolerance to surgery and anesthesia is very important to weigh the risks of surgery.
The purpose of this study was to evaluate the efficacy of surgery in children of different ages,which is reflected in the indicators of length of hospital stay, operative time, chest tube duration, length of ventilation, number of deaths, number of major complications. We found that the indicators of length of hospital stay, operative time, the length of ventilation and number of major complications contain statistical significance.
Notably, some researchers23 used surgical time as a proxy for technical difficulty, which means the shorter duration of surgery reflects fewer problems and accidents during surgery. In addition, studies24, 25 have shown that shortening surgical time can shorten the length of hospital stay, as well as reducing the incidence of surgical site infection within 30 days after surgery, the use of air drainage tube, the possibility of readmission and reoperation23. Especially for children, shorter procedures mean less time spent on anesthetics, which can stunt brain development and damage the nervous system26. In addition, shortening the operation time can enable children to resume normal eating time earlier27, which is of great significance to help the early recovery of growth and development of children.
Some studies have shown that mechanical ventilation is associated with the occurrence of complications, and the incidence of complications increases with the duration of respiratory support28. Shortening the length of ventilation can not only reduce pulmonary complications28, 29, such as postoperative pneumonia, atelectasis, pulmonary edema, acute respiratory failure, tension pneumothorax, and also can reduce extrapulmonary complications, such as gastric insufflation, fistula, anastomotic leakage, bleeding, hospital infection, mask discomfort, damaged skin, eye irritation, sinus congestion, oronasal drying, and patient‐ventilator asynchrony30, 31. It is worth noting that several studies have shown that mortality associated with lung disease is largely related to complications of postoperative re-intubation and mechanical ventilation. This means that reducing the duration of ventilation can reduce postoperative mortality by reducing the incidence of ventilator-related complications32. In particular, children’s lung development is not yet perfect, and changes in forced ventilation, normal pulmonary respiration physiology and respiratory mechanics will lead to respiratory dysfunction and decreased airway clearance ability. Therefore, shortening mechanical ventilation time is of great significance for children’s postoperative recovery33.
Interestingly, one study34 found that the incidence of complications increased with the age of the patient at the time of surgery, and most of the complications were related to pleural problems, mainly including air leakage and fluid accumulation35. Air leakage at the surgical site can lead to surgical emphysema and pneumothorax, while fluid accumulation can lead to chylothorax, and in severe cases they may lead to accidental re-intubation or even reoperation.
In addition, major complications include transient unilateral phrenic nerve palsy, hemorrhage, pneumonia, deep incision or inter-organ space infection, deep wound dehiscence, pulmonary embolism, renal failure or insufficiency, sepsis, and deep venous thrombosis. Minor complications include superficial surgical site infection, superficial wound rupture, and urinary tract infection. In particular, musculoskeletal complications including breast deformity, rib fusion,chest wall asymmetry,pterygoid scapulae and scoliosis are the major long-term complications of thoracotomy36, which have a bad effect on children in skeletal development during growth35. A cohort study published by Markel M et al demonstrated that compared with the general population, children experience more frequent respiratory infections after resection of congenital lung malformations, and Resection does not eliminate the increased risk of pneumonia37.
Extubation time is also one of the perioperative indicators. Ko HK et al. believed that delayed extubation after surgery was significantly associated with a higher proportion of other pulmonary complications, reintubation, mortality, and prolonged intensive care unit and hospital stays38. Studies also have shown that early extubation is beneficial to reduce the pain and stress response of patients, promote early activities, and speed up postoperative recovery, and it is feasible and safe39.However, the clinical extubation time mainly depends on the amount of postoperative thoracic hemorrhage and the surgeon’s assessment, which has individual differences and a certain degree of subjectivity. Our study shows no meaningful difference in extubation time by surgical age.
Postoperative mortality is an important indicator for evaluating the postoperative prognosis of children. Postoperative death may be caused by complications such as heart failure, respiratory failure, infection, etc., which are closely related to the surgical skill of the operator and the conditions of the medical institution. But deaths from lung resections are rare. In center with expertise and experience, CPAM lesions can be safely resect with virtually no mortality40, 41. However, due to the lack of data that can be included at present, larger multi-center clinical trials are needed to further improve the conclusions, and more comprehensively assess the effect of age on clinical outcomes.