Baffle fenestration with subsequent transcatheter closure. Modification of the Fontan operation for patients at increased risk

Ventricular dysfunction, elevated pulmonary vascular resistance, and residual distal pulmonary artery distortion contribute to early mortality after a Fontan operation; they may be transient or reversible. A baffle fenestration, allowing right-to-left shunting, maintains cardiac output and limits right atrial pressure. A baffle fenestration was surgically created at the time of a modified Fontan repair in 20 consecutive patients. Risk factors included pulmonary artery pressure of 18 mm Hg or more, end-diastolic pressure of 12 mm Hg or more, valvar regurgitation, pulmonary artery distortion, pulmonary vascular resistance of 2 Woods' units or more, ventricular outflow obstruction, and complex anatomy. Nineteen of 20 patients survived. After the operation, mean arterial oxygen saturation was 86%, mean right atrial pressure was 15 mm Hg, and mean duration of pleural effusions was 6 days. Twelve of 19 survivors tolerated early test occlusion and had permanent transcatheter umbrella closure. Four patients failed early test occlusion, with a significant decrease in venous O2 saturation and a rise in central venous pressure, due to ventricular dysfunction, pulmonary artery distortion, or aortopulmonary collaterals. Three of four had successful late closure of the fenestration after correction of these abnormalities.     

Closure of extrocardiac Fontan fenestration by using the Amplatzer duct occluder

INTRODUCTION: A direct or tubular communication between the systemic venous system and the systemic atrium, generally called fenestration, is surgically created to improve the postoperative period of patients undergoing total cavopulmonary connection. However, a fenestration prompts a potentially deleterious right to left shunt, and is generally closed after the postoperative period. Direct fenestrations can be closed using coils, or devices designed for atrial septal defect closure. However, no devices have been designed for closure of extracardiac fenestrations. We report our experience concerning the closure of extracardiac Fontan fenestration by the Amplatzer duct occluder (ADO). METHODS: From January 2001 to December 2002, we closed extracardiac Fontan fenestrations using the ADO device in 10 consecutive patients. Indications to fenestration closure were: low velocity shunt through the fenestration, mild desaturation, and absence of effusions. RESULTS: All patients had a successful closure of the fenestration. The procedure was performed through the femoral vein in 7 cases and through the right jugular vein in 3. Mean central venous pressure increased not significantly from 12 to 13-mmHg. Mean oxygen saturation increased significantly from 90 to 97% (p<0.001). Immediate shut abolition was obtained in 9 cases. No complications were observed. At a median follow-up of 12 months (range 6-18 months), all patients are free of symptoms and have a normal oxygen saturation at rest as well as at exertion. CONCLUSION: The ADO device allowed closing the extracardiac Fontan fenestration in all patients with no mortality, no morbidity and a rate of 100% of complete closure at mid-term follow-up.     

Univentricular repair in children under 2 years of age: early and midterm results

BACKGROUND: Encouraging results have been obtained from early univentricular repair. Our study was designed to assess the impact of young age (less than 2 years) on the outcome of univentricular repair. PATIENTS AND METHODS: Between January 1992 and December 1998, 65 out of 311 patients undergoing univentricular repair at the All India Institute of Medical Sciences, New Delhi, were less than 2 years of age. We compared these 65 carefully selected patients (group 1) with the 246 patients who were more than 2 years of age (group 2). Since 1994, all patients of both groups had a fenestration of the intra-atrial baffle. RESULTS: The early mortality rate was 9.2% in group 1 and 7.7% in group 2. The overall Fontan failure rate was 12.3% in group 1 and 12.2% in group 2. In group 1, a higher incidence of Fontan failure was noted in patients with suboptimal weight, non-tricuspid atresia morphology, nonfenestrated Fontan and those who did not comply with more than two of Choussat's criteria, but the values were not statistically significant. Aortic cross-clamp time of more than 60 min was the only and highly significant predictor of Fontan failure (P < 0.01). The overall effusion rate was 24.05% in group 1 and 27.98% in group 2. In group 1, patients weighing less than 10 kg (P = 0.0007), without fenestration of the atrial baffle (P < 0.05) and with systemic ventricular dysfunction (P < 0.001), systemic ventricular end-diastolic pressure of more than 12 mmHg (P < 0.001), mean pulmonary artery pressure of more than 15 mmHg (P < 0.001) and aortic crossclamp time of more than 60 min (P < 0.01), were all found to be significant risk factors of pleural effusion. Pulmonary artery distortion needing reconstruction did not increase the Fontan failure or effusion rates. Oxygen saturation ranged from 85 to 94% (mean 89%) in patients having a functioning fenestration at a mean follow-up period of 30 months. The actuarial survival at 84 months was 90 +/- 0.04% in group 1 and 88 +/- 0.02% in group 2. CONCLUSIONS: Our results suggest that carefully selected patients under 2 years of age are suitable candidates for one-stage univentricular repair and that survival is not significantly different from that of older patients. Routine fenestration of the intra-atrial baffle is an option available to ameliorate morbidity and obviate mortality. Non-compliance with more than two of Choussat's criteria appears to be additive in unsatisfactory outcome.     

Effect of baffle fenestration on outcome of the modified Fontan operation.

BACKGROUND. The "fenestrated Fontan" (surgical baffle fenestration followed by transcatheter test occlusion and permanent closure after postoperative recovery) was adopted in an effort to reduce perioperative mortality and morbidity. This study assesses the effect of baffle fenestration on outcome. METHODS AND RESULTS. Patients having a modified Fontan operation with a cavocaval baffle and cavopulmonary anastomosis were retrospectively selected for study. Those with baffle fenestration (n = 91) were compared with those without baffle fenestration (n = 56) with respect to preoperative risk factors, age, anatomy, surgical date, and presence or absence of a previous bidirectional cavopulmonary anastomosis. Outcome variables were failure (death or take-down) and duration of postoperative pleural effusions and hospitalization. Survival and clinical status after hospital discharge were ascertained. The two groups did not appear to differ with respect to age or anatomic diagnosis. Patients having baffle fenestration were at significantly greater preoperative risk by univariate and multivariate analysis (p < 0.01). Operative failure was low in both groups (11% without and 7% with baffle fenestration, p = NS). Durations of pleural effusions and hospitalization were significantly shorter with baffle fenestration (p < 0.01). Neither date of surgery nor a previous bidirectional cavopulmonary anastomosis appeared to contribute to improved outcome. Patients with baffle fenestration had lower postoperative systemic venous pressure (p < 0.01). There were no late deaths. Functional status in both groups is good (82% in New York Heart Association class I). CONCLUSIONS. Baffle fenestration is associated with low mortality, significantly less pleural effusion, and significantly shorter hospitalization among high-risk patients having a modified Fontan operation.     

Feasibility and clinical impact of transcatheter closure of interatrial communications after a fenestrated Fontan procedure: medium-term outcomes.

OBJECTIVE: This study was to review an institutional experience with transcatheter closure of Fontan fenestrations and its impact on clinical care. BACKGROUND: An interatrial fenestration improves postoperative outcomes in high-risk children undergoing a Fontan repair. While technical feasibility has been well defined, the clinical impact of subsequent closure is not well defined. METHODS: Transcatheter closure of a surgically created or additional interatrial communication was attempted in 152 children at a median interval of 13.8 months after surgery. The clinical records were reviewed for demographic and anatomical characteristics, previous surgeries; catheterization data, and status at latest follow-up. RESULTS: Mean oxygen saturation and right atrial pressure increased acutely from 87% +/- 5% to 96% +/- 3% (P < 0.001) and 12 +/- 2 mm Hg to 13 +/- 3 mm Hg (P < 0.001), respectively. Higher systemic venous atrial pressures after occlusion correlated with higher pulmonary artery pressures (P = 0.05) before the Fontan procedure and with higher right (P < 0.001) and left atrial (P = 0.001) and ventricular end-diastolic pressures (P < 0.001) immediately before occlusion. Complications included device malposition in 2 children, 1 child each had an air embolism and post-procedural bleeding, and each self-limiting and 1 child had acute ST elevation in inferior ECG leads because of occlusion of the acute marginal branch which was treated with angioplasty and placement of a stent. At follow-up (median 4.5 years), the mean oxygen saturation was 95% +/- 3%. Residual interatrial leaks were noted echocardiographically in 9%. Two children developed protein-losing enteropathy after fenestration closure. No deaths or strokes were observed in follow-up. CONCLUSIONS: Transcatheter occlusion of Fontan fenestrations is safe with acute and persistent improvements in oxygen saturations.     

Dilation of intra-atrial baffle fenestrations: Results in vivo and in vitro

Spontaneous closure of intra-atrial baffle fenestrations occurred early postoperatively following a Fontan procedure in three patients (ages 0.8–2 yr) and were reopened using transvenous balloon dilation. Following this clinical experience with this complication we studied the effects of high pressure balloons of different sizes on fenestrations created in polytetrafluoroethylene (PTFE) patches. The intra-atrial baffle fenestration was found closed within hours after surgery in two patients and 32 days postoperatively in the other. Increasing edema, chest tube drainage, and renal dysfunction ensued rapidly. At catheterization the balloon dilation in two patients reduced the elevated right atrial pressure, edema, and pleural effusion and allowed an acceptable arterial saturation. In the other patient, with acidosis and a low cardiac output, transient cardiac arrest occurred following passage of the catheter through the fenestration and during later unsuccessful operation the fenestration, although open, was traversed by strands of clot. In the experimental study, a total of 45 fenestrations 4 mm in diameter were dilated with 5, 6, 7, 8, and 9 mm balloons. The fenestration areas remained increased significantly during the 14 days of observation in room air, with the larger balloons producing larger holes. Balloon dilation may be effective for spontaneous fenestration closure occurring in the early postoperative period after a fenestrated Fontan procedure. Our experimental data may be useful in selecting the balloon size in this setting.     

Use of Amplatzer occlusion devices to occlude Fontan baffle leaks during fenestration closure procedures

The authors describe the use of Amplatzer occlusion devices to successfully occlude Fontan baffle leaks in three patients. These additional right to left shunts were recognized at the time of elective transcatheter closure of surgically created fenestrations. A common site of baffle leak is described at the base of the right atrial appendage. This suture line serves to exclude the right atrial appendage from Fontan baffle flow and lies within the corrugated surface of the pectinate muscles, making it particularly vunerable to baffle leaks over time. © 2008 Wiley‐Liss, Inc.     

Incidence and factors influencing the spontaneous closure of Fontan fenestration

Introduction: The Fontan operation is the final stage of single ventricle palliation in patients with complex congenital heart disease. Fenestration in the Fontan conduit, providing an atrial level right to left shunt, has been shown to reduce early postoperative morbidity. However, there is limited data on the long‐term fate of this fenestration. The aim of this study is to define the rate of spontaneous closure of the fenestration in the Fontan conduit and factors predictive of the fate of the fenestration.
Methods: This was a retrospective study reviewing the medical records of the patients who underwent fenestrated Fontan operation at our center. Preoperative, intraoperative and postoperative variables including the status of the Fontan fenestration were extracted and analyzed.
Results: Of 67 patients included in the study, 15 (22%) had spontaneous closure of the fenestration. Of the remaining 52 patients, 11 (20%) had procedural closure of this fenestration (10 via cardiac catheterization and 1 via surgery) at a median duration of 3 months after the Fontan operation. Patients with higher preoperative pulmonary vascular resistance and a history of postoperative systemic venous thromboembolism had higher likelihood of having persistence of the fenestration with P value of .045 and .037, respectively.
Conclusions: The rate of spontaneous closure of the Fontan fenestration was 22% in our study. Elevated preoperative pulmonary vascular resistance and history of systemic venous thromboembolism are predictive of persistent Fontan fenestration.     

Transcatheter closure of fontan fenestrations using the Amplatzer septal occluder: initial experience and follow-up.

We have recently used the Amplatzer septal occluder to close Fontan fenestrations. Between June 1998 and December 1999, 13 patients underwent transcatheter occlusion of their Fontan fenestrations. Systemic blood flow decreased significantly without a concomitant decrease in pulmonary blood flow. All residual shunts detectable by oximetry were at sites separate from those into which occlusion devices were implanted. One patient developed severe tricuspid regurgitation following the procedure requiring surgical removal of the device. At the last follow-up, all patients were doing well clinically. There were no shunts detectable through or around the devices by echocardiography. Our experience indicates that the location of the fenestration within the Fontan baffle is critical to avoiding device interference with other intracardiac structures. The Amplatzer septal occluder offers an effective means of transcatheter closure of Fontan baffle fenestrations. Although more experience is needed, our current follow-up data suggest that long-term outcomes will be favorable. Cathet. Cardiovasc. Intervent. 51:301-304, 2000.     

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.     

Transcatheter interventions in the early postoperative period after the Fontan procedure

Objective : To analyze the safety and clinical impact of interventional cardiac catheter procedures in the management of early postoperative problems after completion of an extracardiac Fontan procedure. Background : The mortality after Fontan procedure has consistently decreased over the last decade. The role of interventional catheterization to address early postoperative problems in this setting has not been studied systematically. Methods : Over a 9.7‐year period, 289 patients underwent an extracardiac fenestrated Fontan procedure with two early deaths (0.7%) and takedown in four (1.4%). Twenty‐seven patients (9.3%) underwent 32 interventional cardiac catheter procedures at a median interval of 12.2 (1–30) days. The median weight was 14.5 (13.5–25) kg. The case notes and procedure records were reviewed retrospectively. Results : Fontan pathway obstructions were treated in 11 patients with stent implantation with good results and no complications. Stent fenestration of the Fontan circulation was performed in 16 patients with one episode of transient hemiparesis and one episode of pericardial effusion. Three patients underwent initial balloon dilatation of branch pulmonary arteries or fenestration with little effect and underwent stent treatment 6 (5–9) days later. One patient had device closure of a large atrial fenestration. In one patient, residual anterograde pulmonary blood flow was occluded using a device. There were no deaths and in‐hospital course was improved in all. Conclusion : Interventional cardiac catheter procedures can be performed safely and effectively in the early postoperative period after Fontan completion to address hemodynamic problems. These techniques contribute significantly to achieve a very low mortality and address morbidity after Fontan completion. © 2010 Wiley‐Liss, Inc.     

Clinical features and surgical outcome in 25 patients with fenestrations of the coronary sinus

OBJECTIVE: To analyze symptoms, associated anomalies, diagnostic approach, and surgical procedures in patients with partial fenestrations of the coronary sinus, a rare congenital disorder. BACKGROUND: Partial fenestrations of the walls that usually separate the coronary sinus from the left atrium, also known as partial unroofing of the coronary sinus, may result in increased flow of blood to the lungs, cyanosis, or bidirectional shunting. The diagnosis is important, but difficult to confirm. METHODS: We reviewed retrospectively the clinical, echocardiographic, operative, and follow-up data on 25 patients with partial fenestration of the coronary sinus. The patients had a median age of 8 years, and underwent cardiovascular surgery at Mayo Clinic between 1958 and 2003. RESULTS: The initial diagnosis of a fenestration of the coronary sinus was made by the surgeon at repair of other congenital cardiac anomalies, by cardiac catheterization, or by echocardiography. In 14 patients, fenestration was missed during previous cardiovascular surgery. The most common associated cardiac lesions were atrial septal defects within the oval fossa, persistent left or right superior caval veins, and pulmonary or tricuspid atresia. In 7 patients, the symptoms were at least partially attributable to the fenestration, and included dyspnea, cerebral abscess, transient ischaemic attacks, and cyanosis. The fenestration was addressed surgically in 23 patients, and consisted of closure of the mouth of the coronary sinus, creation of an intra-atrial baffle, or direct repair of the fenestration. Death occurred in 1 patient due to complications unrelated to the repair. In the 24 early survivors, who have been followed up for a median of 85 months, 1 patient has died after a third reoperation for complex congenital cardiac disease. CONCLUSIONS: Fenestrations of the coronary sinus are often missed in the preoperative evaluation of congenitally malformed hearts. When associated with right heart hypoplasia, atrial septal defect, or persistent superior caval vein, fenestrations of the coronary sinus should be considered as a possible additional finding. Once the diagnosis has been made, repair is straightforward.     

Characterization and treatment of systemic venous to pulmonary venous collaterals seen after the Fontan operation

OBJECTIVES: To determine the anatomical characteristics of systemic venous collaterals formed after the Fontan operation, and the efficacy of a transcatheter strategy for management. METHODS: We reviewed retrospectively the data from cardiac catherization of 50 persistently cyanotic patients after the Fontan operation. RESULTS: A total of 54 transcatheter interventions were performed, at a mean age of 6.3 +/- 3.5 years, a mean interval of 2.7 +/- 2.9 years from completion of the Fontan circulation. Of 38 patients who had fenestration of the baffle at the time of surgery, 25 had patency of the fenestration, and 24 had the fenestration occluded with a device at the time of interventional treatment for associated venous collaterals. We identified a total of 68 systemic venous collateral channels, of which 36 (53%) were supracardiac, 12 (18%) cardiac, and 20 (29%) infracardiac in origin. The most common site of origin was the brachiocephalic vein (44%), followed by the left phrenic vein (25%). A longer time from surgery, at 3.3 +/- 3.4 years, was associated with the identification of collaterals having a diameter larger than 4 mm (p < 0.01). The mean pulmonary arterial pressure was higher in those with larger compared to those with smaller collaterals (13.3 +/- 2.8 versus 11.1 +/- 2.0 mmHg, p < 0.01). Coils were used for occlusion of 61 vessels, and a Rashkind occluder for the remaining 7. After exclusion of the patients undergoing simultaneous closure of their fenestration, systemic saturation of oxygen increased from 89 +/- 6% to 95 +/- 3% (p < 0.01). CONCLUSION: Venous collateral channels are common in patients suffering progressive cyanosis in the setting of the Fontan circulation. The collaterals increase in size with time, and are associated with higher pulmonary arterial pressures. Transcatheter treatment is feasible, and results in resolution of cyanosis. Only continuing follow-up will show whether further collateralization occurs in time.     

Is it necessary to routinely fenestrate an extracardiac fontan?

OBJECTIVES: This study was conducted to assess the need for, and use of, fenestration of an extracardiac conduit Fontan. BACKGROUND: Fenestration of a Fontan connection has been proposed as a means of improving outcomes of single ventricle palliation. The benefit of fenestration is likely to be greatest in the early postoperative period when patients may experience increased pulmonary vascular resistance and decreased ventricular function due to the effects of cardiopulmonary bypass, aortic cross-clamping and positive pressure ventilation. However, there are potential drawbacks to fenestration. The utility of fenestration with extracardiac Fontan operation has not been determined. METHODS: Since 1992, 81 patients have undergone a modification of the Fontan procedure in which an extracardiac inferior cavopulmonary conduit is used in combination with a previously staged bidirectional Glenn anastomosis. We conducted a retrospective review of these patients. RESULTS: Fenestration was performed selectively in 32 patients (39%), including only 2 of the last 38 (5%). In seven patients, a fenestration was placed or clipped in the early postoperative period without cardiopulmonary bypass. There were two operative deaths. Prolonged (>2 weeks) pleural drainage occurred in 13 patients, 8 with fenestration and 5 without. In addition to undergoing earlier Fontan in our experience, patients who had a fenestration placed had significantly higher preoperative pulmonary vascular resistance, significantly higher common atrial pressure after Fontan and significantly lower post-Fontan systemic arterial oxygen saturation. Fontan pressure did not differ between nonfenestrated and fenestrated patients. At follow-up ranging to five years, there were two late deaths and no patients developed protein losing enteropathy. CONCLUSIONS: Fenestration is not necessary in most Fontan patients when an extracardiac conduit technique is performed as described in this article, and therefore, should not be performed routinely with the extracardiac conduit Fontan. The need for fenestration should be assessed after cardiopulmonary bypass when hemodynamics can be evaluated accurately. Fenestration can be placed and revised easily without bypass and with minimal intervention in patients with an extracardiac conduit Fontan.     

Five-year clinical and echocardiographic evaluation of the Das AngelWings atrial septal occluder

Background

The late outcome of patients treated with atrial septal occluder devices remains incompletely defined. The purpose of this study was to assess the late outcome (range 4-7 years postprocedure) of patients in whom the Das AngelWings septal occluder device was implanted in the atrial septum. We report the clinical and echocardiographic outcome, at an average of 5 years following the procedure, of patients treated with the Das AngelWings device used to close either a secundum atrial septal defect (ASD) or a patent foramen ovale (PFO).

Methods

Thirty-two patients underwent successful percutaneous closure of an atrial septal closure, patent foramen ovale, or fenestration in the lateral tunnel of their Fontan with the Das AngelWings device between June 1995 and March 1998 at Duke University Medical Center. Two of the 32 patients were lost to follow-up. The remaining 30 patients were divided into 3 groups based on indication for device implantation. Group 1 consisted of 14 patients with a secundum ASD and predominantly left-to-right atrial shunting. Group 2 consisted of 8 patients who had a PFO and who suffered a thromboembolic event. Group 3 (compassionate use) consisted of 10 patients with multiple comorbid medical problems with predominantly right-to-left shunting at the atrial level causing hypoxemia. Eight of the patients in group 3 were severely ill at the time of device implantation. The 2 remaining patients in group 3 underwent AngelWings implantation for closure of right-to-left shunting through a Fontan fenestration. Mean follow-up was 59 months.

Results

There was no device embolization. No patient in the ASD or PFO/stroke group had a clinical complication. By radiographic examination, 2 of 27 patients had evidence of fracture of the nitinol framework at 2-year follow-up. Residual shunting was present in 44% at 24 hours, 20% at 1 year, and 18.8% at 2 years by use of Doppler color flow imaging and/or microcavitation echocardiographic studies. Mild mitral regurgitation caused by the AngelWings device occurred in 1 patient.One patient in the compassionate use group had a subsequent neurologic event. Five of the 10 patients in the compassionate use group died of comorbid illnesses in follow-up, none directly related to device complications.

Conclusion

The late clinical outcome of secundum ASD and PFO/stroke patients in this study demonstrates that Das AngelWings closure of the atrial septum is effective and safe. These data are encouraging with respect to the expanding use of other percutaneously implanted ASD occlusion devices, although late clinical safety and efficacy data are needed for the specific devices being implanted.     

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.     

Use of stents to maintain atrial defects and fontan fenestrations in congenital heart disease

Maintaining patent atrial septal communications or fenestrations can be vital in conditions requiring adequate decompression of the atria or Fontan baffle. We have recently deployed stents for this purpose, and the aim of this retrospective analysis is to describe our experience. All 26 patients undergoing such stent placement were retrospectively studied and for neonates with hypoplastic left heart syndrome (HLHS) and patients with Fontan fenestrations, their data were compared to controls undergoing transseptal static balloon dilation during the same time period. All 7 stented neonates with HLHS survived to their Norwood procedure and 57% survived to hospital discharge, similar to those who had static balloon dilation. Complications occurred in both HLHS groups but transient complete heart block was only seen in the control group, which also had larger balloons used (10.3 mm vs 7 mm, P=0.002). The success rate for patients undergoing stent placement in Fontan fenestrations was 64% compared to 76% with dilation alone. Complications were seen in 64% of the Fontan stented group compared to 39% for controls. There were 5 other patients with complex lesions (3 of whom were on the Extracorporeal Membrane Oxygenator) in whom stent placement successfully maintained atrial communication patency. Atrial septal stent placement in neonates with HLHS with restrictive defects is effective and appears at least as safe as static balloon dilation. On the other hand, initial fenestration stent placement is indicated only after extracardiac Fontan procedures in which the previous fenestration location cannot be found.     

Early and late arrhythmias after the Fontan operation: predisposing factors and clinical consequences.

OBJECTIVE--To study the incidence, predisposing factors, and clinical significance of arrhythmias early and late after the Fontan operation for congenital heart disease. PATIENTS AND METHODS--All 104 consecutive patients undergoing Fontan repair from 1975 to 1988 were studied retrospectively. Hospital records were reviewed for perioperative arrhythmia. Clinical information and annual electrocardiograms were available for all 78 hospital survivors during a follow up of up to 13 years (mean 3.7 years). Ambulatory electrocardiographic monitoring was performed in 67 patients (81%). RESULTS--Eleven patients (10.6%) developed a perioperative tachycardia (eight, atrial flutter; three, His bundle tachycardia). Multivariate analysis showed that raised preoperative mean pulmonary artery pressure and low aortic saturation were significant risk factors for the development of atrial flutter (r2 = 0.32, p = 0.0001) but not for His bundle tachycardia. Despite intensive medical treatment 10 of these 11 patients died. At the last visit 72 (92%) of the 78 patients were in sinus rhythm on their standard 12 lead electrocardiogram. Junctional rhythm was present in three patients, two patients had atrial flutter, and one had a paced rhythm. Ambulatory monitoring did not show important bradycardia or ventricular arrhythmias. Actuarial survival free of supraventricular arrhythmia was 82% at eight years after operation. Multivariate analysis identified older age, increased right atrial size, and raised mean preoperative pulmonary artery pressure as risk factors for arrhythmia during intermediate follow-up (r2 = 0.46, p less than 0.001). Late tachycardias, in contrast to those occurring in the perioperative period, were not associated with an increased mortality. CONCLUSIONS--Except for his bundle tachycardia in the perioperative period, early and late arrhythmias after a Fontan operation seem to be a consequence of adverse preoperative and postoperative haemodynamic function. The perioperative outcome is therefore poor even when the patient can be restored to sinus rhythm. Medical and surgical modifications to improve the haemodynamic disturbances associated with arrhythmias are therefore indicated.