Transcatheter Closure Of Patent Ductus Arteriosus With Pulmonary Hypertension Using Domestic-made Mushroom Occluder In Children

BachgroundPatent ductus arteriosus (PDA) is one of the most common congenital heart diseases in children; it is the abnomal access between aorta and pulmonary artery. The incidence accounted for 15% to 21% in congenital heart disease and women are 2 times than men are. One case of PDA can be found in per 2500～5000 newborn babies. If not timely diagnosed and treated, it often can lead to congestive heart failure, chronic lung diseases and intracranial hemorrhage disease, and is one of the main influential factors of the survival and the sequels incidence of premature infants. PDA can lead to pulmonary artery hypertension (PAH) and the constant left-to-right shunt can cause pulmonary plethora, increasing the resistance of pulmonary vascular bed. If not treated on time, PDA can cause inreversible PAH and lost the opportunity for operation. According to statistics [1], if PAH can be diagnosed and treated between 10～14, the 5-year survival rates will be more than 95%; Meanwhile, if PAH was diagnosed and treated above 20, the 5-year survival rates was only 56%. So, it is especially important to treat PDA patients with PAH as early as possible.The traditional treatment method for PDA is surgical ligation, which has massive trauma. How to select indication of PDA patients with severe PAH is a dilemma for both cardiologists and surgeons. If the pulmonary arterial disease is irreversible in these patients, though the PDA is successfully corrected, the PAH will still progress and patients still can not benefit from the intervention.It is critical to select the correct indication to distinguish reversible and irreversible pulmonary arterial disease. It is hard to distinguish only by clinical examination or catheterization, and temoparory surgical occlusion often brings massive trauma and great danger. Transcatheter PDA occlusion started in 1966, and in 1998, Masura[4] first reported successful closure of PDA using Amplatzer mushroom occluder. After that, the technique was introduced into China and began clinical use widely. But the high price of imported occluders hindered the further application of the technique[5-8]. In 2002, domestic PDA occluders became available in treating PDA[9-11]. There was few literature reported about transcatheter PDA occlusion in patients with severe PAH. This study mainly focused on the clinical results of PDA patients with PAH after transcatheter occlusion using domestic PDA occluders. We divided pulmonary arterial disease into reversible and inreversible type in PDA patients with PAH. We tried to prevent the development of irreversible pulmonary arterial disease by on time transcatheter occlusion and improve the left ventricle function of these patients, thus providing theoretical basis and clinical experience for these kind of patients.Aimsto evaluate the efficiency of domestic-made mushroom-shape occluder in children transcatheter closure of patent ductus arteriosus (PDA) with pulmonary hypertension.Methods86 children (30 male and 56 female) with PDA underwent transcatheter closure using domestic-made mushroom-shape occluder. The median age of patients was 7.2±6.4 years (range 8mon to 12y) and the mean weight was 23.2±10.8 kg (rang from11 kg to 36 kg). The mean PDA diameter of narrowest segment was 7.4±4.9 mm (rang from 4.2 mm to 13.4 mm). The achievement of permanent transcatheter closure was decided according to the change of the pulmonary arterial pressure, aortic pressure and oxygen saturation. Follow-up evaluation was performed with echocardiography and X-ray at 24 hours, 1 month, 3 months, and 6 months and 1 year after closure respectively.Results1.Comparison of accuracy of measuring the diameter of PDA, Pulmonary artery systolic pressure (PASP) by using TEE and aortography and catheterization: There was no siginificant difference of the PASP between TEE and catheterization(P>0.05). In PDA≤8mm, there was also no difference of the size measured by TEE and aortography(P>0.05).However, in PDA>8mm, TEE likely to underestimate the actual size and the mean discrepancy with aortography is 2.6mm(P<0.05).2.Changes of pulmonary artery systolic pressure (PASP), pulmonary artery mean pressure (PAMP) and arterial pressure (AP) after transcatheter closure: In 86 patients ,transcatheter closure was successfully performed in 84 patients(97.68%). The PASP decreased from 69.4±24.5 mmHg to 36.3±14.4 mmHg (P<0.01), the PAMP decreased from 45.3±14.2 mmHg to 29.8±8.2 mmHg (P<0.01), AP increased from 94.5±10.3 mmHg to 98.8±6.2 mmHg (P>0.05). SPO2 didn't change (P>0.05) 30 minutes after the procedure. There was no systolic gradient in these 84 patients. However, 2 patients began to manifest high PAP, decreased AP, chest distress and dyspnea after attempt transcatheter occlusion. We retrieved the occluders and the patients relieved after conservative therapy.3.Left ventricle function and Cardio/Thoracic (CT) ratio after transcatheter closure: LAD size decreased from 31.3±4.7mm to 20.4±4.0mm (P<0.01), LVEDD decreased from 48.3±8.4mm to 40.4±5.3mm (P < 0.05), LVEDV decreased from 116.7±35.3ml to 65.4±26.7ml (P<0.01), LVESV decreased from 32.4±13.5ml to 24.3±11.6ml (P<0.05), LVSV decreased from 82.4±30.5ml to 52.3±22.2ml (P<0.01), LVEF decreased from 67.1±7.2% to 62.3±4.2% (P>0.05), LVFS decreased from 36.4±6.5% to 32.2±6.1% (P>0.05), and CT ratio was remarkably reduced from 0.68±0.12 to 0.48±0.12 (P<0.05) 1 month after transcatheter closure in 84 patients (97.68%,). The LAD,LVEDD, LVEDV, LVESV,LVSV,LVEF,LVFS and CT ratio didn't change (P>0.05) after 3 months'follow-up. The LAD,LVEDD,LVEDV,LVESV,LVSV,LVEF,LVFS and CT ratio didn't change (P>0.05) after 6 months'follow-up.Conclusion1. Attempt occlusion using domestic mushroom occluders can effectively distinguish whether the pulmonary arterial disease is reversible in PDA patients with PAH. If it is reversible PAH, transcatheter occlusion can be effective.2.Transcatheter PDA occlusion in PDA patients with reversible pulmonary arterial disease using domestic mushroom occluders can reduce PAH and improve the left heart function.3. Transcatheter occlusion using domestic mushroom occluders is a safe and effective method, having the advantage of being less invasive, fast-recovery over traditional open surgery.