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. Angiography-based 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.     

ST‐segment elevation on intracoronary electrocardiogram after percutaneous coronary intervention is associated with worse outcome in patients with non‐ST‐segment elevation myocardial infarction

The AMPLATZER^TM Vascular Plug 4 (AVP4) is a self‐expandable, replaceable occluder made of Nitinol wire mesh, which allows the safe and effective interventional occlusion of medium size vessels. This report describes an infant diagnosed with pulmonary atresia, ventricular septal defect, and multifocal collateral lung perfusion through four major aortopulmonary collateral arteries (MAPCAs). A central aorto‐pulmonary shunt was performed at 4 months of age. Because of postoperative pulmonary hyperperfusion, one of the MAPCAs was closed interventionally using a 5 mm AVP4. This MAPCA originated from the descending aorta (DAO) near the fifth thoracic vertebra and ran behind the esophagus to the lower lobe of the right lung. The MAPCA was closed near its origin from the DAO. Four weeks later, the patient presented with severe gastrointestinal bleeding, caused by perforation of the AVP4 into the esophagus. The occluder was extracted surgically, the MAPCA was clipped and the esophageal injury was sutured. To date, there have been no reports describing esophageal perforation due to an AVP4. The perforation in this patient may have been due to implantation of the AVP4 near the aorta in a MAPCA segment located directly in front of the spine and behind the esophagus. Another possible factor may have been the requirement for a gastrointestinal feeding tube. Although the occluder is soft and flexible, the spindle‐shaped ends may cause trauma if they are located close to other structures. © 2016 Wiley Periodicals, Inc.     

Implantation of an Absorb bioresorbable vascular scaffold in the stenotic aortopulmonary collateral artery of a young child with Alagille syndrome

Stent implantation in children can be problematic due to the possibility of growth incapacity and difficulties during later surgery. For these reasons, bioresorbable stents may be a good alternative to conventional stents. We report our experience with implantation of an Absorb bioresorbable stent in the stenotic major aortopulmonary collateral artery (MAPCA) of a 1‐year‐old girl born with pulmonary atresia with ventricular septal defect. © 2015 Wiley Periodicals, Inc.     

Evaluation of pulmonary blood supply by multiplanar cine magnetic resonance imaging in patients with pulmonary atresia and severe pulmonary stenosis

The purpose of this study was to assess the capability of multiplanar cine magnetic resonance imaging (MRI) for evaluating pre- and post-operative pulmonary circulation in patients with pulmonary atresia and severe pulmonary stenosis. Seventy-three multiplanar cine MRIs were performed in 30 patients, aged 1 month to 7 years (mean age, 27 months). The morphology and size of the central pulmonary arteries (PA), source of the major aortopulmonary collateral arteries (MAPCA), patency of Blalock–Taussig (BT) shunt vessels, and the post-operative pulmonary circulation were assessed. The accuracy of cine MRI was compared with that of angiography in all patients. The PA was visualized to the first hilar branch in 21 patients, but not in 8 patients in whom the central PA was absent. On follow-up MRI, PA growth was measured, and the results showed excellent correlation with the results obtained by angiography. In 17 patients who had undergone 23 BT shunt operations, cine MRI correctly demonstrated all patient shunts and 5 of 6 stenotic lesions. Multiplanar cine MRI provided excellent detail of the peripheral PA in all patients, 7 of 8 peripheral pulmonary stenoses, 3 of 4 nonconfluent pulmonary arteries, and 2 of 3 PA obstructions. Although the sources of MAPCA were identified in 7 of 9 patients, the distal connection of the MAPCA was not detected in all patients. Seven patients were reexamined after pulmonary plasty; they exhibited normal pulmonary flow patterns. Multiplanar cine MRI provides high-resolution imaging of PA with dynamic visualization of flow and is an effective noninvasive technique for evaluating pre- and post-operative patients with pulmonary atresia and severe pulmonary stenosis.     

Oxygenated right ventricular assist device with a percutaneous dual-lumen cannula as a bridge to lung transplantation

BackgroundOxygenated right ventricular assist device (oxyRVAD) placement has become more streamlined with the introduction of the dual-lumen pulmonary artery cannula. Peripherally cannulated oxyRVAD may provide oxygenation support with right heart support as an alternative to venoarterial extracorporeal membrane oxygenation (ECMO) as a bridge to lung transplantation.MethodsA single-institution, retrospective analysis was performed on patients placed on oxyRVAD with a dual-lumen pulmonary artery cannula with the intention of bridging to lung transplantation in 2019.ResultsFour patients with idiopathic pulmonary fibrosis were placed on oxyRVAD as a bridge to transplantation. Two patients were extubated and ambulated while waiting for a lung offer, and two patients required conversion to venoarteriovenous ECMO (VAV ECMO) from oxyRVAD. The median waiting time for extracorporeal life support (ECLS) was 42 h. All patients underwent double lung transplantation. Two patients stayed on oxyRVAD, and one patient was placed on venovenous ECMO (VV ECMO) after transplantation. Primary graft dysfunction score at 72 h after transplantation was grade 1 in three patients and grade 3 in one patient.ConclusionsPeripherally cannulated oxyRVAD with percutaneous dual-lumen venous cannula could be an ambulatory bridge for lung transplantation. It is unknown whether oxyRVAD is feasible as a long-term bridge to lung transplantation.     

室间隔完整型肺动脉闭锁的彩色多普勒超声诊断

目的 探讨室间隔完整型肺动脉闭锁（PAIVS）的超声影像特点.方法 回顾分析7例PAIVS的超声心动图表现,并与外科手术结果进行比较.结果 PAIVS的超声心动图特征明显：（1）二维超声心动图胸骨旁左心室长轴切面显示室间隔回声完整.（2）心尖四腔切面显示2个心房正位,室间隔回声完整.（3）胸骨旁大动脉短轴切面显示2条大动脉位置关系正常,肺动脉瓣无开放运动,肺动脉瓣无血流信号通过.手术证实7例PAIVS中肺血由未闭的动脉导管供应者6例;主肺动脉及分支发育不良,仅有体肺动脉侧支供应肺血者1例.心房水平右向左分流者7例：其中5例为卵圆孔未闭,2例为房间隔缺损.合并畸形包括三尖瓣闭锁,三尖瓣发育不良伴狭窄、房间隔膨凸瘤等.结论 PAIVS患儿肺血来源多样化,肺动脉发育程度不一,超声心动图特征明显,对PAIVS有特异性诊断价值.     

Diastolic opening of the pulmonary valve in a case of cardiomyopathy with restrictive dysfunction. Case report and review of the literature

In a case of cardiomyopathy with restrictive ventricular dysfunction a complete diastolic opening of the pulmonary valve immediately following the atrial contraction could be visualized by echocardiography and at the same time a forward blood flow into the pulmonary artery could be shown by conventional and color Doppler. The velocity of this flow (0.37 m/s) was as high as the maximal velocity of the systolic outflow. As an expression of the unpaired compliance of the right ventricle and a compensatory hyperkinetic right atrium the heart catheterization revealed a high a-wave of 18 mm Hg, which was transmitted into the right ventricle and the pulmonary artery. This produced a short diastolic pressure drop between the right ventricle and pulmonary artery causing an opening of the pulmonary valve which could be shown by echocardiography. In connection with similar cases in the literature the pathophysiology of this phenomenon is discussed.     

Right Aortic Coarctation and Ventricular Septal Defect: An Unusual Cause of Tracheal Compression in Infancy

Objective. Acyanotic congenital heart diseases may occasionally present with tracheobronchial obstruction. Increased pulmonary blood flow against a high‐resistance pulmonary bed may create significant pulmonary artery dilation. Methods. We report an unusual case of ventricular septal defect and right aortic arch coarctation, complicated with distal tracheal compression secondary to a pincer effect created by a right aortic arch and a massively dilated pulmonary artery. Results. High index of suspicion is required to anticipate tracheobronchial compression in acyanotic congenital heart diseases. Conclusion. Fiberoptic bronchoscopy is an invaluable tool to assess for tracheal compression relief following surgical repair and to identify tracheomalacia prior to extubation.     

Early vancomycin,amikacin and gentamicin concentrations in pulmonary artery and pulmonary tissue are not affected by VA ECMO (venoarterial extracorporeal membrane oxygenation) in a pig model of prolonged cardiac arrest

BackgroundECMO (extracorporeal membrane oxygenation) is increasingly used in severe hemodynamic compromise and cardiac arrest (CA). Pulmonary infections are frequent in these patients. Venoarterial (VA) ECMO decreases pulmonary blood flow and antibiotic availability in lungs during VA ECMO treated CA is not known. We aimed to assess early vancomycin, amikacin and gentamicin concentrations in the pulmonary artery as well as tracheal aspirate and to determine penetration ratios of these antibiotics to lung tissue in a pig model of VA ECMO treated CA.MethodsTwelve female pigs, body weight 51.5 ± 3.5 kg, were subjected to prolonged CA managed by different modes of VA ECMO. Anesthetized animals underwent 15 min of ventricular fibrillation (VF) followed by continued VF with ECMO flow of 100 mL/kg/min. Immediately after institution of ECMO, a 30 min vancomycin infusion (10 mg/kg) was started and amikacin and gentamicin boluses (7.5 and 3 mg/kg, respectively) were administered. ECMO circuit, aortic, pulmonary arterial, and tracheal aspirate concentrations of antibiotics were measured at 30 and 60 min after administration; penetration ratios were calculated.ResultsAll 30 min antibiotic concentrations and 60 min concentration for gentamicin in the pulmonary artery were no different than the aorta. However, the 60 min pulmonary artery vancomycin and amikacin values were significantly higher than aortic, 19.8 (14.3–21.6) vs. 17.6 (14.2–19.0) mg/L, p = 0.009, and 15.6 mg/L (11.0–18.6) vs. 11.2 (10.4–17.2) mg/L, p = 0.036, respectively. One hour penetration ratios were 18.5% for vancomycin, 34.9% for gentamicin and 38.8% for amikacin.ConclusionIn a pig model of VA ECMO treated prolonged CA, despite diminished pulmonary flow, VA ECMO does not decrease early vancomycin, gentamicin, and amikacin concentrations in pulmonary artery. Within 1 h post administration, antibiotics can be detected in tracheal aspirate in adequate concentrations.     

Compliance, alveolar-arterial oxygen difference, and oxygenation index changes in patients managed with extracorporeal membrane oxygenation

Eighteen patients with meconium aspiration syndrome who failed conventional management were treated with extracorporeal membrane oxygenation (ECMO) for reversible respiratory failure. Dynamic lung compliance measurements were made prior to, during, and after ECMO support. P(A-a)O2 and oxygenation index (OI) measurements were calculated prior to and after ECMO support. Lung compliance decreased significantly comparing before-ECMO to during-ECMO, and increased significantly comparing during- to after-ECMO, but not comparing before- to after-ECMO measurements. P(A-a)O2 and OI decreased significantly from before to after ECMO. The improvement in oxygenation allowing removal from ECMO does not appear to be related to improved pulmonary mechanics, but may rather be secondary to increased effective pulmonary capillary blood flow.     

Blood transfusion requirements and independent predictors of increased transfusion requirements among adult patients on extracorporeal membrane oxygenation – a single centre experience

Background/Objectives More adults undergo extracorporeal membrane oxygenation (ECMO) now. They have high transfusion requirements. This study described transfusion requirements of adults during ECMO in a single institution, and determined factors associated with high transfusion requirements. Materials/Methods Retrospective analysis was done on the amount of blood products received by adults during ECMO. Predictors of increased average daily transfusion requirements during ECMO and increased ECMO duration (which correlated positively with total transfusion requirements) were determined. Results Forty‐one patients (median age 50 years) underwent 42 ECMO sessions for respiratory failure (16·7%), cardiogenic shock (76·2%) or massive pulmonary embolism (7·1%). They received 569 red blood cells, 852 platelets, 126 fresh‐frozen plasma (FFP) and 220 cryoprecipitate in total during median ECMO duration of 5 (1–15) days. On multivariate analysis, average daily red blood cell transfusion increased with nadir haemoglobin (Hb) during ECMO (Hb_nadir) of < 7·5 g/dl (P < 0·001). Average daily platelet transfusion increased with recent antiplatelet agents (P = 0·015) and maximum Hb decline of > 5·5 g/dl during ECMO (P = 0·011). Average daily platelet transfusion > 3 units was also associated with increased ECMO duration (P = 0·024). Average daily FFP transfusion was increased in patients with hypertension (P = 0·007) and Hb_nadir < 7·5 g/dl (P = 0·050). Patients with sepsis (P = 0·009) or without surgery (P = 0·009) had increased ECMO duration, which correlated positively with total transfusion requirements during the entire ECMO session. ECMO improved mortality of patients with fulminant myocarditis, respiratory failure and massive pulmonary embolism. Conclusion Adult ECMO patients with lower Hb_nadir require more daily red blood cell and FFP. Hypertension increases daily FFP requirements. Recent antiplatelet agents, larger Hb decline and longer ECMO duration increase daily platelet requirements. Patients with sepsis or on ECMO for medical reasons have longer ECMO duration, which is associated with total transfusion requirements. Some of these factors may be identified early to optimize blood product support.     

Tracheobronchial Obstruction Due to Blood Clots in Acute Pulmonary Embolism with Cardiac Arrest Managed with Extracorporeal Membrane Oxygenation

A 66-year-old Japanese woman developed pulseless electrical activity following an acute pulmonary embolism and was treated with thrombolytic therapy. She remained hemodynamically unstable and therefore underwent extracorporeal membrane oxygenation (ECMO). While receiving treatment with ECMO, blood clots induced by endobronchial hemorrhage caused tracheobronchial airway obstruction, leading to ventilatory defect. Furthermore, her cardiac function improved, resulting in cerebral hypoxemia progression. Therefore, the blood clots were removed with a Fogarty balloon catheter and endobronchial urokinase administration, resulting in improvement in her respiratory condition. Finally, ECMO was decannulated, and the patient was discharged from our hospital without difficulties in her activities of daily living.     

Application of veno-arterial-venous extracorporeal membrane oxygenation in differential hypoxia

Veno-arterial extracorporeal membrane oxygenation (ECMO) through the femoral vein and artery may cause differential hypoxia, i.e., lower PaO₂ in the upper body than in the lower body, because of normal cardiac output with severe impairment of pulmonary function. Hereby, we report the diagnosis and the treatment of differential hypoxia caused by veno-arterial ECMO. A 39-year-old man received cardiopulmonary resuscitation from a cardiac arrest due to acute myocardial infarction. Even after more than 30 min of resuscitation, spontaneous circulation had not resumed. Next, we performed veno-arterial ECMO through the femoral artery and vein, and the patient recovered consciousness on the second day of ECMO. On day 5 of ECMO, he lost consciousness again and presented a generalized tonic-clonic seizure, and an electroencephalogram showed delta waves suggesting diffuse cerebral cortical dysfunction. While an echocardiogram revealed improvements in myocardial function, a follow up chest radiograph showed increasing massive parenchymal infiltrations, and gas analysis of blood from the right radial artery revealed severe hypoxemia. These findings indicated a definite diagnosis of differential hypoxia, and therefore, we inserted a 17-Fr cannula into the left subclavian vein as a return cannula. The patient’s consciousness and pulmonary infiltrations were improved 2 days after veno-arterial-venous ECMO, and the electroencephalogram showed normal findings. To our knowledge, this is the first report of successful clinical management of differential hypoxia. We suggest that veno-arterial-venous ECMO could be the treatment of choice for differential hypoxia resulting from veno-arterial ECMO.     

Airway compression by major aortopulmonary collaterals with 22q11 deletion

Hypoxic choking episodes due to airway obstruction occurred frequently from 4 months of age in a boy with 22q11 deletion, pulmonary atresia, ventricular septal defect, absent central pulmonary artery, tracheobronchomalacia, and an aberrant right tracheal bronchus. The tracheobronchial tree was compressed by a posteriorly displaced ascending aorta and right aortic arch with aberrant left subclavian artery and major aortopulmonary collateral arteries. Single-stage unifocalization and intracardiac repair plus aortopexy at 8 months resulted in resolution of the respiratory distress and heart failure.     

Effect of red cell volume reduction on pulmonary blood flow in polycythemia of cyanotic congenital heart disease

The acute effects of red cell volume reduction (erythropheresis) on pulmonary blood flow and pulmonary vascular resistance were measured in 16 patients with severe shunt-induced polycythemia. In subjects with D-transposition of the great arteries and no significant pulmonary stenosis (Group A) erythropheresis was associated with a decrease in pulmonary vascular resistance and an increase in pulmonary blood flow and in mixing between the systemic and pulmonary circulations. Systemic arterial saturation decreased slightly. By contrast, erythropheresis in patients with severe pulmonary stenosis or atresia and a ventricular septal defect (Group B) was associated with a decrease in pulmonary blood flow and left to right shunt and an increase in right to left shunt. These alterations resulted in a significant reduction in systemic arterial oxygen saturation despite relatively little change in effective pulmonary blood flow. The acute hemodynamic effects of packed red cell transfusion in five patients with D-transposition of the great arteries, no significant pulmonary stenosis and relative anemia were more variable.The observations in patients with shunt-induced polycythemia are probably related to a reduction in blood viscosity produced by a lowering of hematocrit concentration. The reduced viscosity decreases the impedance to flow in the systemic and pulmonary circulations. When pulmonary blood flow is largely derived from the systemic circuit, erythropheresis will diminish pulmonary flow and reduce systemic oxygen saturation. If the pulmonary blood flow is largely independent of the systemic circuit (as in D-transposition of the great arteries without pulmonary stenosis), an increase in total and effective pulmonary flow occurs.     

Acquired coronary-to-bronchial artery communication: A possible cause of coronary steal

An unusual case of an acquired coronary-to-bronchial artery communication is presented. Collateral flow to the lung was provided by the right coronary circulation following obstruction of pulmonary blood flow by chronic pulmonary emboli. A coronary steal phenomenon may have caused an exacerbation of cardiac symptoms by further reducing already compromised coronary blood flow in a patient with atherosclerotic coronary artery disease.     

Iatrogenic coronary artery fistula in a patient with a single coronary artery

Here, we report on a case of coronary artery fistula that developed following the repair of a double-outlet right ventricle (DORV) with infundibular pulmonary stenosis in a patient who has a single coronary artery. The major concern in this case was that of reduction of coronary blood flow from the patient's only coronary artery to the myocardium distal to the fistula.     

Spectral Doppler Interrogation of the Pulmonary Veins in Atrial Septal Defect

The various components of the pulmonary venous (PV) flow are linked to physiological and pathological changes that predominantly occur in the left heart. Thus, spectral Doppler interrogation of the PVs provides hemodynamic insight mainly into left‐sided cardiac function. An exception to the dependence of PV flow on left heart events occurs in the setting of an atrial septal defect (ASD). The latter causes a portion of the PV blood flow, intended to cross the mitral valve, to be channeled into the more compliant right heart. This phenomenon makes the PV flow more dependent on the left‐to‐right interatrial shunt. The identification on the PV Doppler of a pattern that suggests uncoupling with left heart hemodynamics should raise the suspicion of an underlying ASD.     

Unusual cause of neonatal cyanosis

We present a case of a full-term female neonate who presented at 6 h of age with severe cyanosis and was partially responsive to oxygen supplementation. An echocardiogram showed an isolated congenital severe tricuspid valve insufficiency due to rupture of the papillary muscle of the anterior tricuspid valve leaflet. Magnesium sulfate was infused to lower the pulmonary resistance and thus enhancing the antegrade pulmonary blood flow. Ductal patency was secured by prostaglandin infusion thus providing an additional pulmonary blood flow through the ductus arteriosus.The above measures were adequate to stabilize the patient with no further deterioration or the need for other supportive measures such as Nitric Oxide therapy or extracorporeal membrane oxygenation (ECMO). Therefore, early diagnosis and adequate measures to improve the pulmonary blood flow are mandatory, important pre-operative measures in the management of these patients.     

Clinical application of extracorporeal membrane oxygenation (ECMO) in neonatal respiratory failure

ECMO is a therapeutic alternative for newborns with respiratory insufficiency unmanageable by artificial ventilation. A modified heart-lung machine well suited for long-term application is used both to support life and to take over organ function, allowing this organ to rest and to recover. The ECMO-technique as practised in our group is equivalent to the venous-arterial bypass initiated by the Bartlett-team. Venous blood is drained from the right atrium via the right internal jugular vein. After passage through a membrane oxygenator and a heat exchanger it is returned in an arterialized state to the ascending aorta via the right carotid artery. Cannulation is followed by systemic heparinization. With a roller pump extracorporeal circulation is installed for 3-6 days with flow-rates of 80-120 ml/kg/min. The operation is performed under local anesthesia in the neonatal intensive care unit. The typical course of ECMO is stabilization for the first 24-48 hours on high bypass flow rates keeping paO2 at 50-60 mmHg with minimal ventilator settings (Pmax 20 mmHg. FiO2 0.3-0.4). Bypass flow rates can be reduced for the next 24 h and the patient is taken off and decanulated while on similar ventilator settings. Because of systemic heparinization intracranial bleeding is the main complication for a newborn child on ECMO. The incidence is about 10%. Premature infants per se have a high risk of major intracranial bleeding without ECMO. Therefore contraindications are infants under 35-weeks gestation, and a hemorrhage diagnosed by ultrasound prior to ECMO. Prediction of mortality is estimated by the alveoloarterial oxygen gradient (D [Aa] O2).(ABSTRACT TRUNCATED AT 250 WORDS)