Recently, the use of vacuum bells for pectus excavatum has become very common in China, and their promotion has been very aggressive. However, for children using these devices, it's important to be cautious since they have pectus excavatum, a congenital deformity where the sternum is sunken inward and backward. One must ensure these patients do not have congenital heart diseases. If the patient also suffers from congenital heart defects like atrial septal defect, ventricular septal defect, or patent ductus arteriosus, using the vacuum bell to forcefully pull out the sunken sternum might lead to deformation of the heart and worsen the septal defects. Therefore, before using the vacuum bell, it is essential to rule out the possibility of congenital heart diseases in patients, which can be done through an echocardiogram. Secondly, using the vacuum bell with excessive force might cause bruising and capillary bleeding in the patient’s skin.