Transcatheter occlusion of a post-Fontan residual hepatic vein to pulmonary venous atrium communication using the Amplatzer septal occluder

A residual hepatic vein to left atrial communication may result in progressive cyanosis after the Fontan procedure. This problem has usually been treated surgically by ligation or re-inclusion of the residual hepatic vein in the Fontan circulation. Previous attempts at transcatheter closure of such veins have been unsuccessful. An Amplatzer septal occluder was successfully used for transcatheter closure of a post-Fontan hepatic vein to pulmonary venous atrium fistula in an 8 year old boy.     

Transcatheter coil occlusion of coronary artery to right ventricular fistulae in pulmonary atresia with intact ventricular septum

We describe a young adult with an underlying diagnosis of pulmonary atresia with intact ventricular septum and Fontan physiology who presented with extreme dyspnoea on exertion. Coronary artery to right ventricular fistulae and reversible myocardial ischaemia secondary to a right ventricular steal phenomenon were present. The right coronary artery to right ventricular fistula was completely occluded with coils, by a transcoronary approach, with amelioration of symptoms. However, one coil embolised and lodged uneventfully in the left atrium during the procedure. This case demonstrates that a transcatheter approach may be successfully employed not only in patients with isolated coronary artery fistulae, but also in patients with coexistent complex congenital heart disease.     

Relief of an early pulmonary pathway obstruction with stenting after modified Fontan operation in an adult

The prognosis of Tricuspid Atresia, a rare congenital heart disease, has been changed by surgery. The criteria for Fontan operation have been well established in the literature and adult patients rarely fulfil these criteria; however, in very selected cases Fontan operation can be performed also in adults. A 33 year old woman with tricuspid atresia and previous palliation with classical right Glenn and with left modified Blalock-Taussing, underwent modified Fontan operation because increasing cyanosis and moderate exercise intolerance. Three weeks after operation the patient was readmitted with severe heart failure because of a tight obstruction at the anastomosis between right atrium and main-left pulmonary artery. The stenosis was treated with balloon and stenting achieving large pathway. Our experience confirms that after a modified Fontan, if cardiac failure occurs, an immediate full investigation have to be done.     

Extracardiac Fontan fenestration using the SafeSept transseptal guidewire and snare‐controlled diabolo‐shaped covered‐stent placement

Transcatheter Fontan fenestration is a valuable option in situations of prolonged pleural drainage or low cardiac output in patients with failing Fontan circulation. This procedure relies on controlled baffle perforation without separation of the Fontan circuit from the pulmonary venous atrium, and placement of an accurately sized covered stent. We report a novel technique for transcatheter extracardiac Fontan fenestration using the SafeSept transseptal guidewire® and snare‐controlled diabolo‐shaped covered stent placement. © 2015 Wiley Periodicals, Inc.     

Percutaneous transcatheter closure of a large systemic to pulmonary venous fistulae in an adult patient after extracardiac fontan

Vascular fistulae are frequent complications in patients who have undergone a Fontan operation for palliation of single ventricle physiology. Fistulae involving the pulmonary vasculature may result in progressive hypoxemia, pulmonary hemorrhage, and clinical symptoms. These are commonly managed by percutaneous transcatheter embolization utilizing coils, and more recently, vascular plugs and septal occluders. We present a clinical case of an adult patient who underwent an extracardiac Fontan procedure in childhood for univentricular physiology and presented with symptoms of systemic desaturation 10 years after his surgery. The patient was found to have a large fistula from the inferior vena cava to the right inferior pulmonary vein. The fistula was attempted to be closed with a 12 mm Amplatzer Septal Occluder (St. Jude Medical, St. Paul, MN). Angiography showed continued flow across the fistula, which was then successfully occluded with an 18 mm Amplatzer “Cribriform” Septal Occluder (St. Jude Medical, St. Paul, MN). The patient experienced immediate improvement in his systemic saturation, and demonstrates continued resolution of his symptomatic hypoxia on follow‐up. This case illustrates an uncommon systemic to pulmonary vein fistula after Fontan, and a unique, successful embolization with two septal occluders, resulting in sustained symptomatic improvement. © 2015 Wiley Periodicals, Inc.     

Right to left interatrial communications after the modified Fontan procedure: identification and management with transcatheter occlusion.

OBJECTIVE--To describe unusual venous communications from the right to the left atrium resulting in cyanosis after the modified Fontan procedure, and their management with transcatheter occlusion. METHODS--Between September 1992 and November 1994, eight patients were assessed for persistent cyanosis after a modified Fontan procedure. Desaturation was found to be caused by unusual venous shunts originating at atrial level, and transcatheter occlusion with either a double umbrella or coil was attempted. RESULTS--Three types of venous channels were identified. The first type of communication consisted of thin long tortuous channels originating from the right atrial wall, and draining into the left atrium through a capillary network. The second type of communication was in the superior anterior portion of the atrial baffle, incorporating the pectinate muscles of the right atrium, draining into the neoleft atrium. These channels were shorter and often fanned out into small vessels toward the right atrial appendage. In each instance, the shunts were in the superior suture line of a lateral tunnel modification of the Fontan procedure. The third type of communication originated from the inferior vena cava, connecting inferior phrenic veins to pericardial veins and subsequently to the left atrium, at or close to the ostium of the left pulmonary veins. Before device occlusion, the room air aortic oxygen saturation was 88(SD 4)% (range 84% to 94%), and increased to 95(3)% (range 91% to 100%) following occlusion (PL << 0.001). The mean right atrial pressure was 14(4)mm Hg and remained unchanged after occlusion. In six patients there was complete shunt obliteration, while in two both occluded with umbrella devices, a small residual leak persisted. No complication occurred during or immediately after catheterisation. CONCLUSIONS--Unusual venous communications can evolve after the Fontan procedure, resulting in the development or persistence of cyanosis. Some of these communications may be present preoperatively as normal veins draining into the right atrium, enlarging with the increased atrial pressure after surgery. These observations affect long term function after the Fontan procedure. Transcatheter occlusion of these communications is technically feasible and effective, although recurrence may occur.     

Incidence and predictors for the development of significant supradiaphragmatic decompressing venous collateral channels following creation of Fontan physiology

The occurrence of supradiaphragmatic decompressing venous collateral channels following construction of a bidirectional cavopulmonary connection or completion of the Fontan operation resulting in abnormal systemic hypoxemia has been infrequently described. In addition, the incidence and predictors of these channels have not been well delineated, especially in those patients without formation of such structures preoperatively. I evaluated, retrospectively, 40 patients who had undergone either construction of a bidirectional cavopulmonary shunt or completion of the Fontan operation, and who had complete pre and postoperative hemodynamic and angiographic data. Of the patients, 17 (43%) had developed a total of 21 decompressing venous collateral channels, of which 7 (18%) were considered to be hemodynamically significant requiring transcatheter coil occlusion. Of all variables examined, seven patients with significant decompressing collaterals had a greater transpulmonary gradient at follow-up catheterization (8 +/- 2 vs 5 +/- 2 mmHg, p=.01) and lower systemic saturations at routine clinical follow-up visits (82 +/- 5 vs 89 +/- 5 mmHg, p =.007) in comparison to the 33 others. When not evident preoperatively, decompressing venous collateral channels develop in a significant number of patients following conversion to Fontan physiology. If sufficiently large, they may produce lower than expected systemic saturations for the observed cardiac physiology. The larger decompressing channels are more likely to occur when a greater transpulmonary gradient exists postoperatively, which may require cardiac catheterization and transcatheter coil occlusion.     

How to map and ablate atrial scar macroreentrant tachycardia of the right atrium.

A special form of macroreentrant atrial tachycardia (MRAT), due to reentrant activation around surgical scars, can occur in patients after cardiac surgery. Scar MRAT occurs usually after correction of congenital defects, such as atrial or ventricular septal defects, and especially after Mustard, Senning or Fontan procedures, but it can occur also after myxoma, valvular or coronary bypass surgery. The simplest form of scar MRAT is reentry around a lateral right atrial surgical scar. A basic mapping array with multiple simultaneous recordings from the anterior and septal right atrium is very useful to make the electrophysiological diagnosis. A line of double electrograms can be mapped in the centre of the circuit and a fragmented electrogram usually marks the pivoting point between the inferior end of the scar and the inferior vena cava (IVC). Extension of the scar toward the closest fixed obstacle, usually the IVC, by means of radiofrequency ablation, can interrupt the tachycardia and make it non-inducible. Typical atrial flutter usually coexists with scar MRAT and flutter isthmus ablation is probably indicated in all cases. In patients having undergone baffle atrial surgery it can be impossible to map the whole circuit and entrainment-mapping is helpful to localize critical isthmuses in the circuit. After the Fontan operation the right atrium can be severely dilated and scarred, and multiple, complex reentry circuits can be found. Left atrial MRAT based on large areas of scar has been described, but there is still too little experience with these to propose general rules for diagnosis and management.     

Transhepatic approach to create stent fenestration in the extracardiac fontan conduit in a child with dextrocardia and interrupted inferior vena cava with azygos continuation

Plastic bronchitis is a rare life‐threatening complication of Fontan operation. When medical treatment is ineffective in the setting of high systemic venous pressures, Fontan fenestration may be considered to decompress venous pressures and improve cardiac output by creation of the right‐to‐left shunting. However, transcatheter approach can be difficult in patients with complex venous anatomy. We report a 4‐year‐old girl born with hypoplastic left ventricle and heterotaxy syndrome, who developed plastic bronchitis following extracardiac Fontan procedure. Her venous anatomy was complex with dextrocardia and interrupted inferior vena cava with azygos continuation. Stent fenestration was successfully performed via transhepatic approach, which was selected based on the anatomical relationship (between extracardiac conduit, left atrium, and hepatic veins) delineated by pre‐catheterization cardiac MRI. Simultaneous transesophageal echocardiography guided the intervention. Her plastic bronchitis improved significantly in 3 months but slowly progressed after the stent fenestration. At her 8‐month follow‐up, stent fenestration remains open and she is currently under heart transplantation evaluation due to persistent plastic bronchitis. Treatment of plastic bronchitis can be undertaken with Fontan fenestration, with pre‐procedural MRI playing an essential role in patients with complex venous anatomy. © 2012 Wiley Periodicals, Inc.     

Results of transcatheter Fontan fenestration to treat protein losing enteropathy.

Transcatheter fenestration to create an interatrial communication has been used to treat patients with protein losing enteropathy (PLE) after Fontan operation. No systematic data have been reported assessing the results of this procedure. Our institutional database was queried to identify patients after Fontan operation who had transcatheter fenestration to treat PLE. Clinical notes, laboratory data, echocardiograms, and cardiac catheterization data were reviewed. From 1995 to 2005, 16 transcatheter fenestration procedures were performed in seven patients. Median age at fenestration was 18 years (range 13-41 years). Median duration of follow-up was 3.6 years (range 0.2-10.4 years). Techniques for fenestration included blade/balloon septostomy, stent placement, Amplatzer-fenestrated ASD device, and balloon dilation of previous stent. Size of the fenestration created was 5.2 +/- 1.1 mm. Systemic venous pressure remained unchanged after fenestration. Cardiac index increased significantly. Reduction of ascites and edema was noted after 9 of the 16 procedures. Ten of 16 (63%) of fenestrations spontaneously occluded. Three patients are free of ascites although recurrence of PLE occurred in all. One patient with a patent fenestration continues to have ascites. Two patients had Fontan takedown. One patient had conversion to a fenestrated extracardiac conduit Fontan and died postoperatively. The results of transcatheter Fontan fenestration are often disappointing. Maintaining fenestration patency is difficult. Even after "successful" fenestration, resolution of PLE may be incomplete and recurrences have occurred in all. Early consideration should be given to Fontan takedown or cardiac transplant in severely symptomatic patients with PLE who do not respond to fenestration. Transcatheter fenestration may be a bridge to a definitive procedure.     

Percutaneous transhepatic dual chamber pacing in children with Fontan circulation.

Permanent pacing is often required following the Fontan operation and is usually performed epicardially as there is no direct access to the ventricle from the systemic veins. Dual chamber endocardial pacing was achieved by the transhepatic approach in two children with Fontan circulation. The patients were a 7 year old boy with left atrial isomerism, single ventricle with pulmonary stenosis, interrupted inferior vena caval vein with azygous continuation, and direct drainage of the hepatic veins to the right sided atrium, and a 6 year old girl with tricuspid atresia. This approach to endocardial pacemaker implantation is potentially of considerable value in patients who do not have direct access to the ventricle from the systemic veins.     

Current management of late failure after classic Fontan modifications: Fontan conversion

BACKGROUND: Re-establishment of Fontan circulation by eliminating the drawbacks of classic Fontan modifications has been proposed recently to improve the functional class and quality of life of patients with failed Fontan circulation. METHODS: Five patients underwent extracardiac and lateral tunnel Fontan conversion due to failure of the Fontan circulation, after classic Fontan modifications. All of the patients were female and mean age was 10.2 +/- 2.2 years (range: 8-14 years). Previous Fontan modifications were atrio-pulmonary anastomosis in 3 and Kawashima operation in 2 patients. Time to re-operation for Fontan conversion was 6 +/- 1.5 years (range: 4-8 years). Indications for re-operation were right heart failure, right atrial dilatation, and intractable atrial arrhythmias in patients with previous atrio-pulmonary anastomosis, progressive hypoxia and exercise intolerance in patients with previous Kawashima operation due to pulmonary arteriovenous fistulas. Previous atrio-pulmonary anastomoses were converted to intra-atrial or lateral tunnel Fontan operation with modified right atrial Maze procedure. Extracardiac Fontan completion was carried out after previous Kawashima operations by redirection of hepatic veins to the lungs. RESULTS: There was no mortality and no major morbidity. All patients were discharged from the hospital in good condition and in sinus rhythm. No prolonged or recurrent effusions were observed. On follow-up, all patients were in sinus rhythm and had NYHA class I functional capacity. In two Kawashima patients, SpO(2) gradually increased from 60 % to 90 % six months after the operation. DISCUSSION: We suggest that Fontan conversion should be considered in patients with previous atrio-pulmonary anastomosis, when right atrial dilatation or intractable atrial arrhythmias with deteriorating functional status develops. Redirection of hepatic venous flow to lungs induces regression of pulmonary arteriovenous fistulas and improves arterial saturation in patients with previous Kawashima operation.     

Impact of arrhythmia circuit cryoablation during Fontan conversion for refractory atrial tachycardia

Refractory atrial arrhythmias in late postoperative Fontan patients are usually associated with residual hemodynamic abnormalities and result in significant morbidity and mortality. Surgical revision of the Fontan anastomosis may improve hemodynamics without eliminating tachycardia. This study sought to assess the impact of surgical cryoablation of the arrhythmia circuit at the time of Fontan conversion on the clinical recurrence of tachycardia. Sixteen consecutive atriopulmonary Fontan patients with refractory atrial arrhythmias underwent surgical conversion to lateral tunnel total cavopulmonary anastomosis (15) or Fontan revision (1 patient). The initial 4 patients underwent Fontan conversions alone, without specific arrhythmia surgery. The subsequent 12 patients underwent electrophysiologically guided cryoablation of the tachycardia circuits at the time of surgical conversion. The mean age at Fontan revision was 15.6 +/- 3.8 years. Cryoablation was directed to 3 identified major tachycardia circuits: the inferomedial right atrium, the superior rim of the prior atrial septal defect patch, and along the lateral right atrial wall. Transmural antitachycardia pacemakers were implanted in 11 of the 16 patients. There was no surgical mortality in either group, and all patients improved in functional classification. All patients not undergoing cryoablation experienced recurrent symptomatic tachycardia requiring antiarrhythmic therapy (median follow-up, 54 months) versus 2 of 12 patients receiving cryoablation (median follow-up, 25 months; p <0.02). Thus, surgical cryoablation of the arrhythmia circuit at the time of Fontan conversion is highly effective in the management of refractory atrial arrhythmias, and is superior to Fontan conversion alone.     

A new Amplatzer device to maintain patency of Fontan fenestrations and atrial septal defects.

This study evaluated use of Amplatzer fenestrated device to maintain patency of the Fontan fenestration and atrial septal defect. Fenestrations are routinely created in patients with lateral tunnel or extracardiac Fontan. Spontaneous closure of the fenestration can lead to Fontan circulation failure. Other patients without single-ventricle physiology may benefit from a small communication between the left and right atria for decompression if closure of the atrial septal defect leads to failure of a dysfunctional ventricle. Amplatzer septal occluder device was modified to create a fenestration through the disks. Three patients with modified Fontan and one patient with a large atrial septal defect underwent placement of the device by transcatheter technique. The device deployment was guided by transesophageal echocardiography. The procedure was successful in all patients. Contrast injection after placement revealed patent fenestration with free flow. Follow-up ranged from 3 months to 1 year. All devices were patent by transthoracic echocardiography. These preliminary results suggest that the Amplatzer fenestrated device can serve as a valuable tool in failing Fontan circulation and may help to avoid surgical intervention. More studies are needed to assess long-term efficacy of the device.     

Outcome and assessment after the modified Fontan procedure for hypoplastic left heart syndrome.

BACKGROUND. We reviewed the outcome of 76 consecutive patients (age range, 5 months to 6 years; median age, 19 months) who underwent a modified Fontan procedure after initial palliative surgery for hypoplastic left heart syndrome (HLHS) between January 1984 and December 1989. METHODS AND RESULTS. Modifications of the Fontan procedure included transatrial baffle of pulmonary venous return to the tricuspid valve (n = 10) or inferior vena cava baffle within the right atrium to the superior vena caval-pulmonary artery anastomosis, with pulmonary artery augmentation (n = 66). Actuarial survival rates were 74% (1 month), 58% (12 months), 56% (2 years), and 52% (4 years). Of the 43 survivors, 25 patients have returned for postoperative cardiac catheterization at a medium of 13 months after the Fontan procedure. Mean +/- SD hemodynamic values were cardiac index, 2.8 +/- 0.6 l/min/m2; right arterial pressure, 11 +/- 2 mm Hg; pulmonary artery wedge pressure, 6 +/- 3 mm Hg; and arterial oxygen saturation, 94 +/- 3%. No patient had significant tricuspid or native pulmonary valve insufficiency. CONCLUSIONS. Survival after the Fontan procedure in patients with HLHS is comparable to survival after a Fontan procedure in patients with other complex congenital heart lesions. In the subgroup of patients with HLHS who survived both reconstructive surgery and a Fontan procedure and have been evaluated by cardiac catheterization after a Fontan procedure, the use of the right ventricle as the systemic ventricle yielded excellent intermediate results for Fontan physiology.     

The fenestrated Fontan procedure.

In 90 patients with characteristics placing them at increased risk for a Fontan operation, a fenestration was created in the atrial baffle at the time of the Fontan repair. The rational was to allow a right to left shunt which would maintain cardiac output and limit right atrial pressure in the presence of conditions which limit pulmonary blood flow. Early mortality was 4/90 (4%), with an additional two patients having the Fontan repair taken down to a bidirectional cavopulmonary anastomosis. Postoperative right atrial pressures were low (average 13 mm Hg), as was the incidence of prolonged pleural effusions (13%). At short-term (average 13 months) follow-up, 77% of patients have had closure of the fenestration, and 92% are in New York Heart Association Class I. We conclude that baffle fenestration with subsequent transcatheter closure results in decreased mortality and morbidity among high risk patients undergoing a Fontan repair, and that the high functional level at short-term follow-up justifies continued aggressive management of such patients.     

Long term negative pressure ventilation: Rescue for the failing fontan?

Current treatment strategies for single ventricle patients include non-intervention strategy, surgical palliation or primary transplantation. Surgical palliation includes a staged operative course culminating in the Fontan operation. With progress in surgical techniques, the survival has been improving. However, almost all of these Fontan patients will demonstrate pathophysiologic changes that ultimately constitute "Fontan failure physiology". This article reviews the pathophysiologic changes, current approach to management of these patients and proposes a novel way of reversing some of the pathophysiologic changes by utilization of negative pressure ventilation.     

The Fontan Circulation: From Ideal to Failing Hemodynamics and Drug Therapies for Optimization

Fontan palliation results in a hemodynamically complex circulation with multisystem consequences, which in the long term adversely affect many body processes. Systemic venous hypertension, nonpulsatile low-shear pulmonary blood flow, and low cardiac output are the 3 main characteristics of a Fontan circulation, leading to unavoidable slowly progressive failure. An appreciation of how the hemodynamics of a Fontan circulation change with time and relate to the various modes of Fontan circulatory failure is important. Accurate hemodynamic assessment aid this understanding and may permit early identification of potentially treatable drivers of decline. While no evidence-based or guideline-directed pharmacologic management strategy has been established in Fontan patients, understanding the hemodynamics of Fontan circulation failure will assist in the rational selection of potentially helpful drug therapies for individual patients. In this review, we present hemodynamic concepts of the optimal Fontan physiology and Fontan circulatory failure, review practical aspects of invasive hemodynamic assessment, and discuss the role of drug therapies in increasing systemic venous blood flow return and decreasing ventricular filling pressures in Fontan circulation. Often complementary to catheter-based or surgical interventions, pharmacologic management aims at preserving patency of the circuit, adequate systolic and diastolic ventricular function, atrioventricular valve function, an unobstructed ventricular outflow tract, and pulmonary vascular integrity in order to maintain an acceptable cardiac output.     

Experiences with the Fontan operation

Up to December 1980 we performed 21 Fontan operations: 8 for tricuspid atresia and 13 for a functional monoventricle. Although palliative, the operation is currently a good method of treating tricuspid atresia. In our experience, the use of a sufficiently large atriopulmonary valved conduit assures a more satisfactory immediate postoperative hemodynamic result than the atriobulbar non-valved connection (RA-infund. tunnel). Good results can be obtained by a modified Fontan operation in patients with a monoventricle. However, with this malformation, very careful preoperative selection of patients is necessary with special regard to pulmonary vascular resistance. The connection between the right atrium and pulmonary artery was established by a valved conduit in 15 patients; no valve was incorporated in the other 6 patients. The largest prostheses gave the best immediate postoperative hemodynamic results. Two patients with monoventricle were successfully reoperated for persistent right-left shunt. The 13 patients so far followed up for at least a year show definite improvement as compared with their preoperative condition. Late complications from the valved prostheses have not been observed so far.     

Mapping and ablation of atypical flutter in congenital heart disease with a novel three-dimensional mapping system (Carto Merge).

Mapping and successful ablation of an intra-atrial re-entry tachycardia in a patient after Fontan operation were performed within the anatomy, superimposed from the computed tomography study. In this case, the new system enabled us to display the complex anatomy of the right atrium in detail, whereas the conventional electro-anatomic three-dimensional geometry showed significant inconsistencies.