Redirection of the Hepatic Venous Flow for the Treatment of Pulmonary Arteriovenous Malformations after Fontan Operation

A 45-month-old boy who had complex cardiac anomalies with interrupted inferior vena cava and polysplenia underwent extracardiac Fontan operation. He redeveloped deep cyanosis postoperatively. Cardiac catheterization showed a preferential flow of the hepatic venous blood to the right lung and arteriovenous malformations (PAVMs) in the left lung. He underwent revision of the conduit to attain balanced hepatic venous drainage with subsequent regression of the PAVMs and disappearance of cyanosis. Our experience shows that deficiency of hepatic venous flow played a crucial role in the development of PAVMs and that redistribution of the flow retained potential to ameliorate the pathological condition.     

全腔静脉-肺动脉连接术治疗儿童复杂先天性心脏病

目的探讨全腔静脉一肺动脉连接术治疗儿童复杂先心病的方法及疗效。方法年龄0．5～11．5岁的复杂先天性心脏病患儿(单心室伴其他畸形5例，右室双出口伴其他畸形3例，三尖瓣闭锁2例，三尖瓣下移畸形1例)11例施行了心外管道或房内侧壁隧道全腔静脉一肺动脉连接术，采用自体心包6例，采用Gore-Tex管道连接5例，11例中开窗5例。结果全组死亡1例，术后患儿血氧饱和度由65％～85％增加至92％～96％，运动耐力明显增强，心脏容量负荷减轻，血流动力学满意，近期疗效较好。结论全腔静脉一肺动脉连接术操作简捷，血流动力学满意，能有效提高患儿血氧饱和度及减轻心脏容量负荷。术后并发症和病死率较低。     

Pulmonary Arteriovenous Malformation in Patients with Total Cavopulmonary Shunt: What Role Does Lack of Hepatic Venous Blood Flow to the Lungs Play?

We examined the etiology of a long-term postoperative complication, pulmonary arteriovenous malformation (PAVM), in a patient who underwent total cavopulmonary shunt (TCPS). The patient underwent TCPS at the age of 3 years and 1 month, and a PAVM developed. At the age of 10 years, TCPS was switched to total cavopulmonary connection to facilitate circulation of hepatic venous blood to the pulmonary artery. As a result, oxygen saturation increased. These findings suggest that the absence of pulmonary circulation of hepatic venous blood is involved in the development of PAVM.     

Towards the optimal Fontan operation: a single-institution experience

Many groups, including ours, have played a more or less significant role in the development and evolution of the Fontan operation that has taken place over the past four decades. This is a brief review of the contributions developed by our institution. Contributions to clinical and technical areas include: development of the ventricular exclusion concept; promoting the staged approach to the Fontan operation by bidirectional cavopulmonary anastomosis with or without a modified Damus–Kaye–Stansel anastomosis; endorsement of the total extracardiac cavopulmonary connection; a rational approach to the management of systemic venous aberrances in single-ventricle patients; and criteria for transition to heart transplantation. Contributions to computational fluid dynamics include: investigation of the best spatial arrangement for the total extracardiac cavopulmonary anastomosis and identification of the so-called ‘beneficial vortex’; studies on the effect of unbalanced pulmonary resistances on the hydrodynamic performance of the total extracardiac cavopulmonary connection; and a rationale for the management of systemic venous anomalies in single-ventricle patients.     

Surgical Removal of Pulmonary Arteriovenous Malformations Subsequent to Total Cavopulmonary Connection Conversion Long After a Björk Procedure

Because the cavopulmonary shunt procedure is widely used for palliation of complex congenital heart diseases, pulmonary arteriovenous malformations (PAVMs) are relatively well-known complications. The reported patient was a 23-year-old woman who experienced PAVMs in the right lower lobe after a classical Glenn anastomosis and Björk procedure for tricuspid atresia. Her arterial oxygen saturation (SaO₂) 14 years after the Björk procedure was ~80 %. She then underwent a total cavopulmonary connection (TCPC) conversion to reduce her PAVMs in the right lower lobe using the “hepatic factor.” However, her situation remained unchanged, and she experienced severe systemic cyanosis (SaO₂, 70 %) and dyspnea during physical exertion without hemoptysis due to increased blood flow to the PAVMs. Although interventional embolization was considered, it was impossible due to considerable dilation of the main PAVM. Thus, right lower lung lobectomy was performed. After surgery, the patient’s SaO₂ increased to 90 %. To the authors’ knowledge, this is the first case report of a lung resection for residual PAVMs after TCPC conversion.     

Results of 100 Consecutive Extracardiac Conduit Fontan Operations

Throughout the years, the experience with Fontan's operation has increased and has opened the way to a much wider application of this principle. A number of major risk factors have been identified and managed by several modifications of the original Fontan procedure. In the past 15 years, operative and postoperative risks have been controlled to a major extent by the application of intermediate surgical procedures. Modifications to the original technique have been designed to simplify surgery and better protect the myocardium by avoiding, as much as possible, prolonged ischemic time. In 1988, we developed a new form of total extracardiac right heart bypass by means of associating an extracardiac conduit placed between the inferior vena cava (IVC) and the pulmonary artery with a bidirectional cavopulmonary anastomosis (BCPA)--the so-called total extracardiac cavopulmonary connection (TECC).Between November 1997 and October 2003, 100 patients with complex cardiac anomalies underwent a modified Fontan operation by TECC. In 88 patients, the repair was staged by preliminary BCPA that was bilateral in 15 patients and associated with a modified Damus-Kaye-Stansel procedure to bypass a subaortic obstruction in 24 patients. Early (in hospital) deaths occurred in 6% of patients and the extracardiac conduit was taken down in 2 additional patients for a total early failure rate of 8%. The cause of death was myocardial failure in 5 patients. Pulmonary artery distortion or hypoplasia appeared to be the cause of death in 1 patient and the cause of failure in 1 patient. Atrioventricular valve regurgitation was the cause of failure in 1 patient. Follow-up to December 2003 was available in all surviving patients. There were no late deaths. At follow-up, 87 patients (89%) were in New York Heart Association (NYHA) functional class I, 4 in class II, and 3 in class III due to moderate to severe atrioventricular valve regurgitation. Use of the following guidelines can result in the achievement of orthoterminal repair with complete separation of pulmonary and systemic circulation, with negligible early mortality and a long-term NYHA class I: (1) Not all patients with univentricular heart (UVH) should undergo the extracardiac Fontan procedure; (2) in UVH with favorable streaming, a Q (p)/Q (s) ratio of approximately 1 to 1, and mild cyanosis, natural history might be preferable to surgical history; (3) any form of fenestration is contradictory to orthodox application of Fontan's principle. Children in whom a planned fenestration seems necessary because of suboptimal conditions should instead undergo a combination of BCPA and associated forward pulmonary blood flow; and (4) negligible mortality should be considered mandatory in UVH, normal pulmonary arteries, and absent cardiomegaly after appropriated and correct staging.     

Fontan Conversion Templates: Patient-Specific Hemodynamic Performance of the Lateral Tunnel Versus the Intraatrial Conduit With Fenestration

Intraatrial-conduit Fontan is considered a modification of both extracardiac and lateral-tunnel Fontan. In this study, the patient-specific hemodynamic performance of intraatrial-conduit and lateral-tunnel Fontan with fenestration, considered as conversion templates, was investigated based on the authors’ patient cohort. Pulsatile computational fluid dynamics simulations were performed using patient-specific models of intraatrial-conduit and lateral-tunnel Fontan patients. Real-time “simultaneous” inferior and superior vena cava, pulmonary artery, and fenestration flow waveforms were acquired from ultrasound. Multiple hemodynamic performance indices were investigated, with particular focus on evaluation of the pulsatile flow performance. Power loss inside the lateral-tunnel Fontan appeared to be significantly higher than with the intraatrial-conduit Fontan for patient-specific cardiac output and normalized connection size. Inclusion of the 4-mm fenestration at a 0.24 L/min mean flow resulted in a lower cavopulmonary pressure gradient and less time-averaged power loss for both Fontan connections. Flow structures within the intraatrial conduit were notability more uniform than within the lateral tunnel. Hepatic flow majorly favored the left lung in both surgical connections: conversion from lateral-tunnel to intraatrial-conduit Fontan resulted in better hemodynamics with less power loss, a lower pressure gradient, and fewer stagnant flow zones along the conduit. This patient-specific computational case study demonstrated superior hemodynamics of intraatrial-conduit Fontan over those of lateral-tunnel Fontan with or without fenestration and improved performance after conversion of the lateral tunnel to the intraatrial conduit. The geometry-specific effect of the nonuniform hepatic flow distribution may motivate new rationales for the surgical design.     

Modified Fontan procedure for left atrial isomerism: Alternative technique

Anomalous systemic or pulmonary venous connections increase the risk and technical difficulty of the modified Fontan procedure. This report describes an alternative technique of total diversion of systemic venous return to the pulmonary artery in a child with left atrial isomerism, incorporating an extracardiac conduit between the hepatic veins and the right pulmonary artery.     

Morphological Studies of Pulmonary Arteriovenous Shunting in a Lamb Model of Superior Cavopulmonary Anastomosis

We sought to identify and characterize the abnormal vascular structures responsible for pulmonary arteriovenous shunting following the Glenn cavopulmonary shunt. Superior cavopulmonary shunt is commonly performed as part of the staged pathway to total cavopulmonary shunt to treat univentricular forms of congenital heart disease, however, clinically significant pulmonary arteriovenous malformations develop in some patients after the procedure. The causes of pulmonary arteriovenous malformations and other pulmonary vascular changes that occur after cavopulmonary shunt are not known. Using a juvenile lamb model of superior cavopulmonary anastomosis that reliably produces pulmonary arteriovenous malformations, we performed echocardiography and morphological analyses to determine the anatomic site of shunting and to identify the vascular structures involved. Pulmonary arteriovenous shunting was identified by contrast echocardiography in all surviving animals (n = 40) following superior cavopulmonary anastomosis. Pulmonary vascular corrosion casts revealed abnormal tortuous vessels joining pulmonary arteries and veins in cavopulmonary shunt animals but not control animals. In conclusion, unusual channels that bridged pulmonary arteries and veins were identified. These may represent the vascular structures responsible for arteriovenous shunting following the classic Glenn cavopulmonary shunt. Detailed analysis of these structures may elucidate factors responsible for their development.     

心外管道全腔肺分流手术的临床应用

目的 探讨心外管道全腔肺分流手术在小儿复杂青紫型先天性心脏病中的应用价值.方法 1998年1月至2008年10月48例患儿接受了心外管道全腔肺分流手术,其中男37例,女11例;年龄3.1～14.5岁,平均(5.6±3.0)岁;体重13～56 kg,平均(21.1±10.3)kg;三尖瓣闭锁23例,单心室20例,右心室双出口(远离大动脉型)2例,室间隔完整的肺动脉闭锁2例,法乐四联症伴完全性房室间隔缺损1例;术前SPO270%～93%,平均(80.2±6.1)%.38例患儿在行心外管道全腔肺分流手术前接受多次手术,包括改良BT分流5例次,肺动脉环缩4例次,双向腔肺分流手术36例次.12例患儿在同一次手术中完成全腔肺分流手术.结果 术后早期死亡3例;乳糜胸7例,气胸2例,胸腔金葡菌感染1例,短暂的交界性心动过速2例,均治愈;术后胸腔引流放置3.5～48 d.随访1个月至12年,晚期死亡2例,其余35例心功能恢复至Ⅰ级,6例心功能Ⅱ级,2例心功能Ⅲ级,随访心电图均为窦性心律.统计分析Ⅰ期Fontan和分期Fontan在术后机械通气时间、监护时间、引流时间,病死率上无统计学差异.结论 心外管道全腔肺分流手术术后心律失常的发生率低,开窗术有助于围术期恢复,Ⅰ期Fontan在部分患儿中是可行的.     

Temporary Pulmonary Vein Stenosis During Intraoperative Transesophageal Echocardiography in Total Cavopulmonary Connection

Two patients operated on by one of the authors (MK) developed hemodynamic instability after otherwise uneventful completion of total cavopulmonary anastomosis with an extracardiac tube. In both, a stenosis of the right pulmonary veins was demonstrated during routine intraoperative transesophageal echocardiography. The transesophageal probe was found to be the underlying problem. Apparently, the pulmonary veins became compressed between the probe and the extracardiac conduit.     

Resolution of Acquired Pulmonary Arteriovenous Malformations in a Patient with Total Anomalous Systemic Venous Return

An 11-year-old male with total anomalous systemic venous return had surgical repair except for the hepatic venous return, which drained to the left atrium. He developed progressive cyanosis and fatigue and was diagnosed with large pulmonary arteriovenous malformations (PAVMs) during cardiac catheterization with the use of bubble contrast echocardiography. After surgical redirection of hepatic venous flow to the right heart and pulmonary arterial system, resolution of these PAVMs was demonstrated clinically and by contrast echocardiography. This unique case report demonstrates the development of PAVMs with exclusion of hepatic venous return through the pulmonary vascular bed while pulsatile pulmonary blood flow remains intact. It reinforces the likelihood of the absence of an as yet unidentified hepatic vasoactive substance as the source for development of PAVMs.     

Imaging in congenital pulmonary vein anomalies: the role of computed tomography

Pulmonary venous anomalies comprise a wide spectrum of anatomical variations and their clinical presentations may vary from the relatively benign single partial anomalous pulmonary venous connection (PAPVC) to the critical obstructed total anomalous pulmonary venous connection (TAPVC). We briefly review the common anomalies encountered, while highlighting the utility that computed tomographic angiography (CTA) provides for this spectrum of extracardiac vascular malformations and connections. CTA has established itself as an invaluable imaging modality in these patients. A detailed knowledge of the CTA imaging findings in pulmonary venous anomalies is crucial to guide clinical decision-making in these patients.     

Fulminant development of pulmonary arteriovenous fistulas in an infant after total cavopulmonary shunt

An infant with cyanotic congenital heart disease and polysplenia syndrome developed profound cyanosis within months of undergoing bilateral cavopulmonary anastomoses. Intrapulmonary shunting was diagnosed by contrast echocardiography with peripheral venous and selective pulmonary artery injection. Histopathology revealed abnormal, thin-walled vessels within the interstitium of the lung lobule. These vessels have not been reported previously and are likely to be the anatomic site of arteriovenous shunting. This case demonstrates that pulmonary arteriovenous fistulas (PAVFs) may develop rapidly after cavopulmonary anastomosis in young infants. It also illustrates the use of contrast echocardiography for following PAVF progression in these patients.     

Successful management of living donor liver transplantation for biliary atresia with single ventricle physiology—from peri‐transplant through total cavopulmonary connection: A case report

Children with single ventricle physiology have complete mixing of the pulmonary and systemic circulations, requiring staged procedures to achieve a separation of these circulations, or Fontan circulation. The single ventricle physiology significantly increases the risk of mortality in children undergoing non‐cardiac surgery. As liver transplantation for patients with single ventricle physiology is particularly challenging, only a few reports have been published. We herein report a case of successful LDLTx for an 8‐month‐old pediatric patient with biliary atresia, heterotaxy, and complex heart disease of single ventricle physiology. The cardiac anomalies included total anomalous pulmonary venous return type IIb, intermediate atrioventricular septal defect, tricuspid regurgitation grade III, coarctation of aorta, interrupted inferior vena cava, bilateral superior vena cava, and polysplenia syndrome. Following LDLTx, the patient sequentially underwent total cavopulmonary shunt + Damus‐Kaye‐Stansel at 3 years of age and extracardiac total cavopulmonary connection (EC‐TCPC) completion at 5 years of age; 7 years have now passed since LDLTx (2 years post–EC‐TCPC). We describe the details of the management of LTx in the presence of cardiac anomalies and report the long‐term cardiac and liver function, from peri‐LDLTx through EC‐TCPC completion.     

Double Aortic Arch Associated with Common Inlet Left Ventricle

A double aortic arch is usually an isolated abnormality. We report a case with a previously undescribed combination of double aortic arch and common inlet left ventricle. The patient underwent division of the nondominant right aortic arch and the right ductus arteriosus at 2 months of age following a left modified Blalock-Taussig shunt. At 3 years of age, extracardiac total cavopulmonary connection was successfully performed via bidirectional cavopulmonary anastomosis.     

A very rare case of polysplenia syndrome with congenital diffuse pulmonary arteriovenous fistulas

A five-year-old girl patient was admitted with cyanosis and dyspnea, which started from birth. She had small telangiectatic lesions on her face and cerebral arteriovenous malformation, but no family history of hereditary hemorrhagic telangiectasia. Contrast echocardiography and pulmonary angiography demonstrated diffuse pulmonary arteriovenous fistulas. The patient was diagnosed as polysplenia syndrome characterized with left atrial isomerism, interrupted inferior vena cava, azygous continuation to the superior vena cava, and hepatic veins draining to the right atrium. In contrast to the other polysplenia syndrome cases, in this patient, pulmonary arteriovenous fistulas were not associated with cavopulmonary anastomoses or liver disease.     

Fenestration in Extracardiac Conduits in Children After Modified Fontan Operation by Implantation of Stent Grafts

Three patients (ages 3, 5, and 8 years) with various forms of functionally univentricular heart lesions received a total cavopulmonary connection with an extracardiac conduit as a final reconstructive procedure. Failure of the Fontan circulation occurred immediately after surgery because of spontaneous closure of surgical fenestrations in two children and absent fenestration in one. As an emergency procedure, in all patients the conduit was perforated by transcatheter intervention in order to create a connection to the anatomical right atrium. Following balloon dilatation of the perforated conduit, in all three patients covered stent grafts were placed in the newly created defect to attain a reliable communication. Patency of the fenestration was demonstrated by angiogram and any leakage was ruled out. Cardiac output improved and severe pleural effusion and ascites subsided. Right-to-left shunt could be demonstrated by echocardiography at follow-up after 7 months (median) in all three patients. Oxygen saturation remained stable between 85 and 90%. These preliminary results suggest that stent graft fenestration can serve as a valuable tool in failing Fontan circulation, particularly in patients with an extracardiac conduit. Covered stents have the potential to reduce the acute risk of bleeding and they help to prevent early spontaneous closure of the newly created fenestration.     

Interventional catheterization in children

In children, interventional catheterization is performed to treat congenital heart diseases: balloon atrial septostomy; balloon valvotomy for valvar pulmonary stenosis, valvar aortic stenosis, valvar mitral stenosis; balloon angioplasty for venous or arterial stenosis. Transcatheter vascular occlusion can be accomplished using a wide range of devices: transcatheter patent ductus arteriosus closure, embolisation of arteriovenous malformations, systemic-pulmonary collaterals and other extracardiac shunts. Intracardiac or intravascular catheters can be removed.     

Double total anomalous pulmonary venous connection

We present a newborn infant with right atrial isomerism, complex congenital heart malformation and anomalous pulmonary venous connection, reliably diagnosed by 2-D Doppler color echocardiography. The infant had no significant obstetric antecedents. The neonatal clinical picture included cyanosis, heart murmur and respiratory distress. The infant was treated with prostaglandin from the age of 24 hours until his death after surgery. The 2-D echo Doppler color flow mapping showed findings that suggested right atrial isomerism, severe left ventricular hypoplasia, pulmonary atresia and ductus arteriosus. The pulmonary veins flowed together to a posterior cardiac chamber from which an emissary vertical venous vessel connected with a left superior aneurysmal sack. Two venous channels emerged from this sack: one connecting to the innominate vein and the other to the atrium. The malformations were confirmed by cardiac catheterization. On the sixth day of life, the patient underwent anastomosis between the posterior venous chamber with the atrium, a modified Blalock-Taussig shunt implant, and ductus closure but died during surgery. The association between complex cardiac anomalies and uncommon obstructive total anomalous pulmonary venous connection in the context of right atrial isomerism is lethal and few neonates survive surgical repair. Two-dimensional echo color flow Doppler is a reliable diagnostic technique and an indispensable guide in angiography.