DISCUSSION
Wheezing has a high incidence of respiratory tract infection in infants and young children. In the UK, more than 70 per cent of babies and almost all children under the age of two become infected with bronchiolitis each year , Up to 20% of people with congenital heart disease are hospitalized and have a high morbidity and mortality rate[ 7] . Congenital heart disease is also considered a risk factor for recurrent wheezing [8] . Early intervention in children with preexisting heart disease can effectively reduce wheezing attacks caused by infection.
except to infection, compression of the tissues or blood vessels around the trachea can also cause wheezing, which can be the result of the abnormal relationship between the tracheobronchial tree and the vascular structure (the production of vascular rings), it may also be due to pulmonary artery expansion, left atrium enlargement, huge cardiac hypertrophy or external compression caused by intraluminal bronchial obstruction [9]. When patients have recurrent lower pulmonary infections and wheezing episodes, less common causes (including cardiac ones) should be considered, despite wheezing being controlled [10] .
The wheezing reported here was caused by compression of the left main bronchus following release of the ADOII occluder for patent ductus arteriosus.
For small PDAs, spring plugs were often used, the operation is complex, the residual shunt occurs higher. AGA (AGA Medical Corporation, Golden Valley, MN) ADOII has been in clinical use since 2008 and has solved this problem well. The new Amplatzer Catheter Occluder (ADO II) is safe and effective for PDA treatment in children up to 2 years of age, effectively closing PDAs under 2mm [11,12] .
The ADOII was developed specifically for small to medium sized catheters[13] , Major adverse events include obstruction of the descending aorta or pulmonary artery, but the overall incidence is low[14] .
Previous reports focused on the compression of blood vessels by embolization devices, but did not focus on the effect of blood vessels adjacent to the trachea. Therefore, we report these findings in order to evaluate the presence of adjacent tracheal compression in addition to the presence of intravascular flow obstruction during patent ductus arteriosus occlusion.