Clinic Study Of Cardiac Catheterization Angiography And Interventional Treatment After Norwood Procedure

Background and objective:Hypoplastic Left Heart Syndrome(HLHS) refers to the grouping of certain congenital defects. The main characteristics are the marked hypoplasia(underdevelopment)or even absence of the left ventricle and severe hypoplasia of the ascending aorta.Without surgical intervention,HLHS is fatal. Nowadays staged reconstruction is the treatment of choice for HLHS. Reconstruction takes place in three stages:the first stage, known as a Norwood operation,is undertaken as soon as possible after birth. The second stage of reconstruction is undertaken between three and10months of age. Stage two involves performing a bidirectional Glenn shunt or a hemi-Fontan.At18to24months of age,the third stage of reconstruction is possible. This involves the completion of the Fontan procedure. The main purpose of Norwood procedure is to rebuild left ventricular outflow tract and pulmonary blood flow, make anatomical right ventricular to left ventricular function, and finally into single ventricle with pulmonary artery stenosis. In recent years, progress in surgical techniques4and the improved outcomes in stage I of the Norwood procedure5have improved the possibility of survival in neonates with hypoplastic left heart syndrome.However, patients who survive neonatal surgery may develop obstruction in the aortic arch, distortion of the pulmonary arteries,6-8right ventricular dysfunction, or tricuspid regurgitation, which can prevent completion of the Fontan procedure and lead to higher interstage mortality than observed in other forms of univentricular circulation.treatment by catheterization techniques are essential for improving long-term survival and quality of life of these patients. At present the hospital in China which can carry out the Norwood surgery is rare, therefore, the application of cardiac catheterization in single ventricle after operation patient hemodynamic evaluation and treatment of clinical experience. This paper reviewed13patients, who had undergone the Norwood procedure (prior to the Glenn procedure) received cardiac catheterization and angiography in2009in the children’s heart center in Germany corresponding cases of interventional therapy, the postoperative catheterization results and interventional therapy for a summary.Methods:13patients after the Norwood procedure, the age at which interventional catheterization was done ranged22days to8months (135.4±66.879days),the weight ranged from3.1--6.7kg (4.987±1.0803kg).The patients consisted of10cases of HLHS,1case TA, ASD, VSD, subaortic stenosis, the arch of aorta dysplasia, COA,1case unbalanced AVSD, hypoplastic left ventricle and arch of aorta, PDA,1case TGA, hypoplastic left ventricle, AS, VSD, ASD.Ten patients underwent an operation following the classic Norwood procedure (modified right Blalock-Taussig shunt) and3following the modified Sano technique (right ventricle-pulmonary artery conduit). Catheterization was done under general anesthetic and orotracheal Intubation, by percutaneous femoral artery and vein puncture or by puncture of the jugular vein. In the hemodynamic study, particular attention was paid to ruling out obstruction of the neoaorta, atrial gradient, right ventricular function, state of the Blalock-Taussig shunt or the right ventricle-pulmonary artery conduit, pulmonary pressures and resistances, and anatomy of the pulmonary tree. Interventional therapy was performed in12patients as indicated.:(1)Balloon aortic valvuloplasty for the coarctation of aorta:In6of the12patients, significant obstruction was observed in the aortic arch (peak right ventricular descending aorta gradient≥10mm Hg, with angiographic imagining indicating a reduction in diameter of>50%).Then all were performed angioplasties.(2)Stent implantation for the branch of pulmonary artery stenosis:an infant was aggravate cyanoze with no significant reason two months after Norwood procedure. The echocardiography was not obviously abnormal. The X-ray showed left lung blood less. Then the patient received a cardiac catheterization and angiography. Left pulmonary artery stenosis was found. The stenosis site was dilatated with the balloon of3,4,5mm. However, the implantation of stent did not complete.Three months later the patient received another intervention. The balloon with stent from the right axillary artery across BT-shunt to the stenosis site. A Formula stent (7*16mm) was implantated.(3) Stent implantation for the stenosis of systemic to pulmonary shunts: In2patients with Sano-Shunt stenosis and1patient with BT-Shunt stenosis stents were implanted to improve pulmonary blood flow.2case received2stents,1case received3Stent. The Stents were Koronar-Stent.(4) Mapkas embolizations:4cases were found Mapkas in the angugraphy Transcatheter coil embolization was performed in3of the4patients with systemic to pulmonary collateral vessels. The other one was scheduled for Glenn procedure the next day.Results:(1) The gradient of pressure from right ventricular to descending aorta <70%before the intervention. And a case occured recoarctation. He received another balloon aortic plasty for the coarctation of aorta, with satisfactory effect.(2) The left pulmonary artery was significant widened after the implantation of the stent. And the left lung blood increased. The artery saturation since71%up to83%.(3) After the stent implantation for the stenosis of systemic to pulmonary shunts,The artery saturation of the patients since54%,60%,57%up to75%,81%,80%.(4)After the Mapkas embolizations, the Mapkas were closed angugraphy.Conclusion:The incidence of hemodynamic restrictions after Norwood procedure is high(12of13patients). The consequent angiographic and hemodynamic assessment for diagnosis and interventional treatment of pulmonary artery or aortic arch stenoses is mandatory after the Norwood procedure.