| Background and Objective The patent ductus arteriosus (PDA) is a common congenital heart disease (CHD), accounting for approximately 8% of all CHD. In 1998, Masura et al firstly reported that using Amplatzer duct occluder(AGA Medical,Golden Valley,MN) was closured successfully. Recently transcatheter occlusion of PDA has replaced surgery for closure of PDA. It is important to judge whether pulmonary hypertension is reversible before closure of PDA with severe pulmonary hypertension (SPH), but it is difficult for surgery to estimate the quality of pulmonary hypertension. Compared with the traditional open-heart surgical ligation, the percutaneous approach has the advantages of being less invasive, associated with shorter procedural and recovery time, and better cosmetic outcome. Percutaneous transcatheter closure of PDA has been established as a safe and effective alternative to surgical closure, but more experience of occluding PDA with SPH has not been obtained. There are many problems to be resolve, for instance some individual were dead or became worsen after occlusion of PDA with SPH.Unfortunately, at present follow-up of large-scale cases has not been reported, the effectiveness of medium- and long-term has not been confirmed, there must be a standard criterion to abide by. We reviewed fifty-two cases of PDA with SPH in recent years in our institution, we proposed our criterion of transcatheter occluding PDA with SPH. We assessed immediate short and intermediate-term results of percutaneous PDA with SPH using duct occluder by transthoracic echocardiography, electrocardiogram, clinical symptom and sign, oxygen saturation of femoral artery (SaO2).Methods From March 2003 to April 2007, 52 consecutive patients having isolated PDA with SPH were reviewed. A physical examination, chest radiography, a standard 12-lead electrocardiogram (ECG), transthoracic echocardiography (TTE), SaO2 wereperformed in all patients before percutaneous closure to confirm the PDA, a complete hemodynamic evaluation was performed with pressure and saturation measurements taken in all cardiac chambers. A biplane descending aortogram in anterioposterior and lateral projection was performed with a 4F～6F pigtail catheter, which was introduced percutaneously to define the size and anatomy of the ductus. A proper size occluder was then choosed so that the the smaller diameter of the device was at least 5mm larger than the narrowest diameter of ductus(usually pulmonary end of the ductus). Because the device can be easily retracted into the delivery sheath, we first placed the occluder in the appropriate position, but did not deploy it, monitoring the variance of artery pressure and oxygen saturation, judging the nature of pulmonary hypertension. If pulmonary pressure was decreased above 20% or 30mmHg and oxygen saturation of femoral artery was still higher than 90%, PDA can be closured permanently because nature of SPH is dynamic or reversible. Two-dimensional and color Doppler echocardiographic study, ECG, a chest radiography, SaO2 were performed at 24h,1,3,6,12 month and serially yearly thereafter. At each follow-up visit, complications related to device implantation were noted, such as residual ductual flow and left pulmonary artery or aortic stenosis and the wire fracture. The right ventricular end-diastolic diameter(RVEDD), left ventricular end-diastolic diameter (LVEDD), left atrial diameter(LAD), left ventricular ejection fraction(LVEF) and left ventricular shortening fraction(LVFS) were measured by TTE examination, left ventricular end-systolic volume(LVESV) and left ventricular end-diastolic volume(LVESV) were calculated by the single-plane area-length method. Datas of pre- and post-operation was analyzed to explore the variance of ventricular function and conformation.Results Aortogram showed funnel type PDA in 42 cases, tubular type PDA in 10 cases. The mean PDA minimal(pulmonary end) diameter determined by aortography was 8.7±1.8(range 6.0 to 12.0)mm.All patients were underwent experimental transcatheter closure test before releasing duct occluder. Forty-seven cases were successfully closured because pulmonary hypertension was dynamic type, the mean duct occluder smallest diameter was 16.4±2.8mm(range 8.0 to 20.0mm); 5 cases could not be closured because pulmonary hypertension was irreversible or resistant. The systolic pulmonary hypertension of 47 cases was decreased from 65～140mmHg(95±24mmHg) to 65～140mmHg(45±15mmHg), the mean pulmonary hypertension was decreased from 53～102mmHg(66±20mmHg)to 20～73mmHg( 32±14mmHg ) , implying for permanent transcatheter closure. Pulmonaryhypertension of 5 cases failed to respond after the procedure, implying resistant pulmonary hypertension, the permanent transcatheter closure was not recommended and the occluder was removed. Aortography 30 minutes after closure showed 45 cases had complete closure, 2 cases had a trace residual shunt that disappeared after one month by TTE, all 47 patients (100%) were revealed complete closure by color Doppler flow mapping. There was no evidence of device recanalization, migration, wire fracture, haemolysis, thromboembolism or endocarditis. Results of TTE showed that left atrium diameter(LAD), left ventricular end-systolic volume(LVESV) adjusted to body surface area(BSA), left ventricular end-diastolic volume(LVEDV) adjusted to BSA, left ventricular end-diastolic diameter(LVEDD) were decreased significantly compared with those before closure(P﹤0.05).Conclusion Before transcatheter closure of PDA with SPH, we should judge the nature of pulmonary hypertension, we should abide by the strict standard that PDA with reversible SPH can be closured permanently. Based on our experience, transcatheter closure of PDA with reversible SPH is a feasible, effective and safe interventional therapy. The early results and medium-term outcome is credible with regard to the incidence of residual shunt and complications, the function and confirmation of left ventricle improved. But further studies are required to document its efficacy, safety and long-trem results in a large-scale of patients. |
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