A Novel Perspective on Histopathology Provides Novel Insights into Surgical Effects in Pulmonary Atresia,Ventricular Septal Defect,and Major Aortopulmonary Collateral Arteries:A Case-Series Study

Background:Never had literatures characterized the relationship between the property of major aortopulmonary collateral arteries(MAPCAs)and outcomes of selective unifocalization of pulmonary atresia with ventricular septal defects and MAPCAs.Methods:This is a case-series study.Thirteen patients were included.Angiographybased assessment was conducted to determine whether collateral arteries should be unifocalized or treated with intraoperative ligature.Specimens were collected and stained by HE and ET+VG.Results:Twelve patients underwent one-stage unifocalization at a median age of 37 months(range:6–228 months)and a median weight of 14.0 kg(range:5.0–49.0 kg),which produced a favorable right ventricle to aortic systolic pressure ratio of no more than 0.5 except in one patient who died.Patients were divided into three groups:Group 1(n=6),had no native pulmonary arteries,and collateral arteries supplied all pulmonary blood;Group 2(n=6)presented dysplastic native pulmonary arteries on one or both sides,and in some lung lobes or segments,blood was supplied only by collateral arteries;Group 3(n=1)had well-developed left and right pulmonary arteries,and collateral arteries,and pulmonary arteries provided blood flow to the same segments.Pathological reports demonstrated two types of collateral arteries:Elastic arteries presented an arborization distribution similar to native pulmonary artery walls,while muscular arteries showed high resistance and distortion.We selectively unifocalized single-supply collateral arteries with morphologic features based on the arborization distribution.Conclusions:We found that there were two kinds of MAPCAs with different histology,and we performed selective UF for MAPCAs that might belong to the elastic artery.Selective unifocalization achieved a low right ventricle to aortic systolic pressure ratio and favorable surgical effects.

Original article：A novel two-stage complete repair method for pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries

Background Pulmonary atresia with ventricular septal defect （PA-VSD） and major aortopulmonary collateral arteries （MAPCAs） remains a challenging complex congenital heart disease nowadays. In the present study, we aimed to develop a two-stage surgical method and to evaluate outcomes of this method in managing PA-VSD and MAPCAs. Methods Between December 2003 and December 2008, 7 female and 4 male patients between the age of 5 and 10 years who were suffering from PA-VSD and MAPCAs were selected and recruited. The native pulmonary artery trunks were absent in all patients; the lungs were solely supplied by major aortopulmonary collaterals, and the numbers of supplied lung segments ranged from 15 to 20 （17.9±1.6）. There were a total of 43 MAPCAs in all the patients （3-5 （3.9~0.7） MAPCAs per patient）. The accumulated Nakata index was （222.9＋_29.9） mm2/m2 （ranged from 182 to 272）. All the patients underwent two sequential operations. Stage one included left major aortopulmonary collateral unifocalization and modified Blalock-Taussig shunt from left posterior lateral thoracotomy; stage two comprised right unifocalization, ligation of the shunt, followed by ventricular septal defect closure and right ventricular outflow tract reconstruction assisted with cardiopulmonary bypass from midline sternotomy. Results All the patients survived the initial surgery, but one of them died of low cardiac output syndrome on the third day after the second operation. Postoperative complications included pneumonia in one case and capillary leak syndrome in another. Postoperative oxygen saturation maintained about 95%-100%, which was significantly higher than pre-operation （P 〈0.01）. During the follow-up period of 3-51 （25.4±15.2） months, there were no late death and no need for reintervention. All the patients enjoyed their lives with good conditions. Conclusions This two-stage complete repair strategy was well-tolerated and effective with good outcome, thus offering an alternative surgical approach in the treatment of PA-VSD and MAPCAs.

Isolated Major Aortopulmonary Collateral Artery Causing Heart Failure: Transcatheter Occlusion of Mapcas Using Amplatzer Vascular Plugs and Amplatzer Piccolo Occluders

Major aortopulmonary collateral arteries (MAPCAs) are congenital vessels that arise from the aorta or its first-order branches and are distally connected to the pulmonary arterial vasculature, thereby providing pulmonary blood flow. MAPCAs are often associated with cyanotic congenital heart disease with decreased pulmonary blood flow. Isolated MAPCAs are rare in patients without congenital heart disease with structurally normal hearts. Sometimes, isolated congenital MAPCAs can occur without any lung disease. Isolated MAPCAs represent the occurrence of collaterals in the absence of underlying heart disease, which commonly presents as heart failure, recurrent respiratory tract infection, and pulmonary artery hypertension. We report a rare case of congestive heart failure in a 6-year-old patient with dual arterial supply to an otherwise normal right lung, with a normal bronchial tree, and a structurally normal heart. The patient was successfully managed by the closure of collaterals by Amplatzer vascular plugs II (AVPII) and Amplatzer Piccolo Occluders.

Pulmonary Hypertension Crisis in Patient with Tetralogy of Fallot and Mixed Total Anomalous Pulmonary Vein Connection after the Primary Correction:A Rare Case Report

Tetralogy of Fallot(TOF)with total anomalous pulmonary vein connections(TAPVC)is a rare type of complex congenital heart disease among all TOF cases.Co-presentation of major aortopulmonary collateral arteries(MAPCAs)compensates for the lack of central pulmonary bloodflow and decreases the severity of right-to-left shunting in TOF.We present a case of a 2-year-old child with complex diagnoses of TOF,TAPVC,a large secun-dum atrial septal defect(ASD),and intraoperatively identified MAPCAs.She underwent surgery to repair the TAPVC,valve-sparing reconstruction of the right ventricular outflow tract,interventricular defect closure,and the creation of patent foramen ovale(PFO).After the operation,hemodynamic instability happened along with sudden blood pressure drop,desaturation,and increased central venous pressure,which subsided after adminis-tering inhalational nitric oxide(NO).A postoperative pulmonary hypertension crisis was suggested when the patient experienced recurrent symptoms after the termination of NO.Echocardiographicfindings of a D-shaped left ventricle(LV),right-to-left PFO shunt and high tricuspid valve gradientfirmly established the diagnosis.It was subsequently managed with continuous NO inhalation and sildenafil,which rendered a satisfactory outcome.Repaired TOF and TAPVC could be at particular risk of developing pulmonary hypertension crisis,especially in the presence of MAPCAs due to possible remodeling of the pulmonary vasculature.Furthermore,a relatively non-compliant LV function and small left atrial size may exacerbate the risk of developing postcapillary pulmonary hypertension after TAPVC repair.A successful postoperative outcome calls for a meticulous preoperative analysis of the anatomical lesions,as well as careful monitoring.

The Clinical Application Value of Selective Unifocalization in the Treatment of Severe Pulmonary Artery Atresia with Ventricular Septal Defect

Background:This study aims to explore the efficacy of selective unifocalization(UF)for major aortopulmonary collateral arteries(MAPCAs)unifocalization in children with pulmonary atresia with ventricular septal defect(PA/VSD).Methods:A retrospective analysis of 13 patients with PA/VSD/MAPCAs who underwent surgery from June 2017 to December 2019.Sex,age,preoperative cardiovascular angiography test results and McGoon ratio were collected.The properties of the collateral arteries were evaluated by angiography,and selective UF for the“dendritic”MAPCAs and ligation of MAPCAs demonstrating distortion and resistance.Results:A total of 13 severe patients underwent one-stage repair,of which 1 case underwent ventricular septal fenestration and died after 2 weeks of ECMO support.The median age was 37 months,and a median weight was 14.0 kg.A right ventricular to aortic systolic pressure ratio(pRV/pAo)of no more than 0.5 was achieved in 12 living patients.Conclusion:Selective unifocalization based on MAPCAs morphology can achieved a good outcome at the early stage.This surgical concept might be provided a novel insight into treatment for some of the subgroups presenting with this complex form of PA/VSD/MAPCAs.