PS was first reported by Rokitansky in 1981, and the etiology and pathogenesis of this disease remain unclear[8], which may be related to the imbalance of cell proliferation and apoptosis[9]. Compared with congenital cystic adenomatoid malformation(CCAM), aberrant feeding arteries of PS mainly arise from the thoracic aorta, followed by the abdominal aorta, intercostal artery, and subclavian artery[3, 10]. Studies[3, 11]have showed that PS was associated with many deformities, such as diaphragmatic hernia, congenital heart disease, cyst of bronchial origin, funnel chest(pectus excavactum or pectus carinatum). With the popularization of prenatal examination, PS has increasingly been detected by prenatal ultrasound or incidentally found on postnatal CT imaging. However, it’s still challenging to identify an IDEPS. The study found that [12]the arise of PS during the 9th to 12th weeks of embryonic development may have a higher chance of forming within the diaphragm.
The diagnosis of an IDEPS mainly included Prenatal ultrasound, enchanced CT, or magnetic resonance imaging(MRI), play an important role in the surgical planning and safe operative resection. Prenatal ultrasound is a prefer method for the diagnosis of fetal PS [13], However, due to the special location of a sequestered mass in diaphragm, it is difficult to definitely diagnose if the mass is located in the diaphragm using prenatal ultrasound. The detection rate of fetal IDEPS proving the condition was 40% in our study. MRI is of a value method in diagnosing an IDEPS, which can provide multi-level anatomical location information of lesions, and is superior to prenatal ultrasound in assessing the feeding arteries and venous[14]. However, the diaphragm may be affected by respiratory activity, limiting the application of MRI to identify an IDEPS. Given the limitations of MRI, CT scan is less affected by respiratory activity, and has a higher concordance rate for characterising the lung parenchyma, especially the reformatted imaging of CT scan can demonstrate the presence of a mass enveloped by the diaphragm. What’s more, CT is the most accurate method for the detection of a systemic vasculature to the mass. Although CT scan has the risk of ionizing radiation, it is the most efficient choice among the compared methods to identify an IDEPS. Hong et al. [5] reported that 11 cases of IDEPSs had been confirmed after birth using enhanced CT, but Olivieri et al.[15] suggested that a diagnosis could only be confirmed at surgery. In our institution, the concordance rate of CT was 70% and the feeding thoracic aorta and abdominal aorta account for 50%, which were lower compaired with previous study[5, 16, 17]. A 3D reconstruction software was used to provide access to more and higher-quality information about patient's 3D anatomy, making it possible to improve the accuracy and reliability of diagnosis and treatment. This seems to be the first report that a 3D reconstructed imaging clearly showed the relationship between a mass and a diaphragm and was helpful for the identify an IDEPS.
Although the appropriate management of PS remains controversial, majority of surgeons suggested PS should be surgically resected [1, 3, 11, 18], and surgical resection should be performed no more than 12 months of the age[3, 18]. Beatrice et al.[1] reported that paediatric patients operated on after 1 year of age developed more respiratory symptoms than those treated before 1 year of age. Stanton et al.[8] found that the rate of postoperative complications of symptomatic PS were significantly higher than that of asymptomatic PS patitents undergoing elective surgery. However, some studies[18–20] demonstrated that an EPS may remain asymptomatic throughout life and even involute over time, suggesting the safety of just following up EPS without surgery management. In currently, VATS has become the main surgical technique with the advantage of minimally invasive, accurate and rapid recovery. Some studies [21–23]had reported the application of transcatheter arterial embolization (TAE) in the treatment of PS. By embolizing the feeding artery, PS occurs ischemia, necrosis and fibrosis. However, patient may suffer from coil deviation, incomplete embolism, recurrence, hemoptysis and infection. In addition, the risk of exposure to ionizing radiation should be concerned, and further longitudinal study is required to validate this new technique. There are very few reports on the management of IDEPS till now. Due to the special location of an IDEPS, it is difficult to differentiate from a neuroblastoma, an adrenal tumor or a teratoma, and has a risk of infection. Once confirmed, we chose surgery treatment and the best path was access the mass from the chest, which were consistent with Hong et al. [5]. During surgery, the aberrant feeding vessels and ruptured diaphragm should be properly managed to avoid massive bleeding and diaphragm expansion. One case who was treated with VATS in our center suffered from infection, making it difficult to identify the feeding vesses, dissociate the tissue and resect the lesion, all of which led to an increse of operative duration and postoperative thoracic catheter indwelling duration. Laparoscopic surgery was successfully performed in one case, however, it was difficult to found the mass during the operation, and resulted in the prolongation of the operative duation and increase of intraoperative blood loss volume.
To our knowledqe, this is the first report of DVRATS for the treatment of an IDEPS. Compared with VATS, the robotic-assisted systems could allow a three-dimensional (3D) magnified view of the surgical field (10–15 times magnification power), eliminate hand tremors and provide a wider range of motion to the surgical performance, all of which make it easier to complete ligation of the feeding vessel, resection of the mass and subtle suture. What’s more, we found that the length of stay after operation and postoperative thoracic catheter indwelling duration in Group 2 were significantly shorter than that of Group 1. However, due to the limited experience and long preparation time, the first case managed with DVRATS cost more time than other cases. The limitations of expensive equipment, high cost and complete absence of touch sensation restrict its wide application.