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

Impact on clinical outcomes from transcatheter closure of the Fontan fenestration: A systematic review and meta-analysis

BACKGROUND

Meta-analysis of the impact on clinical outcome from transcatheter closure of Fontan fenestration.

METHODS

Cochrane, Embase, MEDLINE, and Open-Gray were searched. Parameters such as changes in oxygen saturation, cavo-pulmonary pressure, maximum heart rate during exercise, exercise duration, and oxygen saturation after fenestration closure were pooled and statistical analysis performed.

RESULTS

Among 922 publications, 12 retrospective observational studies were included. The included studies involved 610 patients, of which 552 patients (90.5%) had a fenestration. Of those patients, 505 patients (91.5%) underwent attempt at trans-catheter closure. When it could be estimated, the pooled overall mean age at trans-catheter fenestration closure was 6.6 ± 7.4 years, and the mean follow-up time was 34.4 ± 10.7 months. There were 32 minor (6.3%) and 20 major (4.0%) complications during or after trans-catheter Fontan fenestration closure. The forest plots demonstrate that following fenestration closure, there was a significant increase in the mean arterial oxygen saturation of 7.9% (95% CI 6.4-9.4%, p < 0.01). There was also a significant increase in the mean cavo-pulmonary pressure of 1.4 mmHg (95% CI 1.0-1.8 mmHg, p < 0.01) following fenestration closure. The exercise parameters reported in 3 studies also favored closing the fenestration as well, yet the exercise duration increase of 1.7 min (95% CI 0.7-2.8 min, p < 0.01) after fenestration closure is probably clinically insignificant.

CONCLUSION

Late closure of a Fontan fenestration has the impact of improving resting oxygen saturation, exercise oxygen saturation, and a modest improvement of exercise duration. These clinical benefits, however, may be at the expense of tolerating slightly higher cavo-pulmonary mean pressures.

Hemodynamic assessment of atrial septal defects

Atrial septal defect (ASD) is one of the most common congenital cardiac anomalies. ASD can present as an isolated lesion in an otherwise normal heart or in association with other congenital heart conditions. Regardless of the type of ASD, the direction and degree of shunting across the communication is mainly determined by the difference in compliance between the right and left ventricle. Hemodynamics in children is characterized by left-to-right shunting, dilated right heart structures and normal pulmonary artery pressures (PAP). Patients diagnosed at adult age often present with complications related to long-standing volume overload such as pulmonary artery hypertension and right and left ventricular dysfunction. Diagnostic catheterization is usually not indicated unless there is suggestion of pulmonary hypertension on echocardiography. In older patients and/or in those with ventricular dysfunction, measurement of left heart pressures during temporary balloon occlusion is recommended prior to device closure as it may not be tolerated. In ASD associated with other congenital malformations, shunting degree and direction will depend upon underlying condition. Restrictive ASD can result in significant hemodynamic compromise in neonates with conditions such as hypoplastic left heart syndrome (HLHS) and transposition of the great arteries (TGA). In most cases, hemodynamics can be estimated with echocardiography only.

Determinants and clinical significance of flow via the fenestration in the Fontan pathway: a multimodality study

BACKGROUND

The use of a fenestration in the Fontan pathway remains controversial, partly because its hemodynamic effects and clinical consequences are insufficiently understood. The objective of this study was to quantify the magnitude of fenestration flow and to characterize its hemodynamic consequences after an intermediate interval after surgery.

METHODS

Twenty three patients with a fenestrated extracardiac conduit prospectively underwent investigation by cardiac magnetic resonance (CMR), echocardiography, and invasive manometry under the same general anesthetic 12 ± 4 months after Fontan surgery. Fenestration flow was determined using phase contrast CMR by subtracting flow in the Fontan pathway above the fenestration from Fontan flow below the fenestration.

RESULTS

Fenestration flow constituted a mean of 31 ± 12% (range 8-50%) of ventricular preload. It was associated with a lower Qp/Qs (r = -0.64, p=0.001) and oxygen saturation (r = -0.74, p<0.0001). Fenestration flow volume was correlated with pulmonary vascular resistance (r = 0.45, p = 0.04) and markers of ventricular diastolic function (early diastolic strain rate r = 0.57, p = 0.008 and ventricular untwist rate r = 0.54, p = 0.02). In 14 patients (61%) all of the net inferior vena cava flow and part of the superior vena cava flow were diverted into the systemic atrium and did not reach the lungs.

CONCLUSIONS

Fenestration flow can be measured accurately with CMR. In two-thirds of the patients not only all of the inferior vena cava flow, but also some of the superior vena cava flow is diverted through the fenestration. Fenestration flow is driven by a balance between pulmonary vascular resistance and early diastolic ventricular function.

Late catheter interventions in hypoplastic left heart syndrome

Interventional cardiology plays a key role in the diagnosis and management of patients with functionally univentricular physiology after the various stages of surgical palliation. The interventions performed are widely variable in type, including angioplasty of stenotic vessels and implantation of stents in stenotic vessels; closure of defects such as collaterals, leaks in baffles, and fenestrations; creation of fenestration; and more. In the setting of venous hypertension associated with stenosis at the Fontan baffle, conduit, or pulmonary arteries, stent implantation is often preferred, as the aim is to eliminate completely the narrowing, given that relatively mild stenosis can have a significant detrimental hemodynamic effect in patients with functionally univentricular circulation. The procedure is highly successful. In patients who fail after Fontan procedure, creation of a fenestration is often performed, with variable technique depending on the underlying anatomic substrate. To increase chances of patency of the fenestration, implantation of a stent is often required, particularly in the setting of an extracardiac conduit. For those patients with cyanosis and favorable Fontan hemodynamics, closure of the fenestration is performed using atrial septal occluder devices with high success rate. Coils compatible with magnetic resonance imaging are used widely to treat collateral vessels, although on occasion other specific embolization tools are required, such as particles or vascular plugs. Postoperative arch obstruction is successfully managed with angioplasty at a younger age, while implantation of a stent in the aorta is reserved for older patients. Specifics of these interventional procedures as applied to the population of patients with functionally univentricular hearts are described in this manuscript.

Percutaneous management of a Fontan fenestration: in search for the ideal restriction-occlusion device

OBJECTIVE

Most devices devices available for percutaneous closure of Fontan fenestrations tend to be bulky. The aim of this study was to evaluate a low profile custom made device and assess its efficacy and safety.

PATIENTS AND METHODS

A 15 mm PFO star was used as the basis. The following modifications were made: removal of the left disc to reduce thrombogenicity in the left atrium, increase the length of the LA legs from 2 by 15 mm to 3 by 20 mm to prevent dislodgement and later adding a pivot between the left and right umbrella. A partial occluder was made by removing two opposite quadrants from the proximal disk.

RESULTS

Device deployment was possible in 93% (63 of 68) patients. In five patients, the device could not be deployed and an alternative device was used. In 45 patients complete closure of the fenestration was obtained and saturations increased from 84% +/- 4% to 95% +/- 2% (P < 001). In 18 high risk patients with suboptimal Fontan circulation, a modified device was used to effect partial occlusion: saturations increased from 79% +/- 7% to 90% +/- 4% (P < 0.001); a residual shunt persisted in most patients for several months. No thrombotic events were recorded during follow-up.

CONCLUSIONS

The modified PFO star device can safely be deployed in Fontan patients to occlude or restrict flow through a fenestration. It has a low profile with minimal foreign material, is non-obstructive and minimally thrombogenic.

Interventions complementing surgery as part of multistage treatment for hypoplastic left heart syndrome: one center's experience

BACKGROUND

Interventional procedures often are used as part of multistage treatment for hypoplastic left heart syndrome (HLHS). This study aimed to evaluate the efficacy of interventions in multistage treatment of HLHS.

METHODS AND RESULTS

Between 1999 and 2007, 78 interventions were performed for 58 children with HLHS at different stages of surgical treatment. Group 1, involving 30 interventions for 22 patients with postoperative pulmonary arterial stenosis, showed reduced pulmonary artery pressure and increased vessel diameter. Group 2, involving 15 interventions after the Norwood operation for 12 patients with aortic arch obstruction, showed success for 11 patients. Group 3, involving eight balloon angioplasties of narrowed Glenn anastomosis for seven patients, showed abolition of the pressure gradient between the superior vena cava and the right pulmonary artery. Group 4, involving eight interventional closures of a fenestration for eight patients after a Fontan operation, showed increased oxygen saturation for all eight patients. Group 5, involving seven interventions for six patients in whom venovenous collaterals were closed percutaneously, showed improved oxygen saturation. For Group 6, uncommon miscellaneous interventions were used to stabilize the patients' condition before the next surgical treatment.

CONCLUSIONS

Interventional procedures play an important role during multistage treatment of HLHS. They allow for a reduction in the number of operations or stabilization of the patients' condition before the next surgical treatment.

Transcatheter closure of fenestration with detachable coils after the Fontan operation

We report our experience in 13 patients who underwent transcatheter closure of Fontan fenestration with the Cook detachable coils. These patients underwent the extracardiac type Fontan operation with a short conduit fenestration (n=7) or lateral tunnel type with a punch-hole fenestration (n=6). Fenestration closure was done at the mean age of 5.1+/-2.4 yr, average of 32 months after the Fontan operation. We used one to three coils depending on the fenestration type, size, and residual shunt. Aortic oxygen saturations increased by an average of 5.4 (2-9)% and mean pressures in the Fontan circuit increased by an average of 2.1 (0-6) mmHg. During follow-up (median of 23 months), five patients (4 in extracardiac, 1 in lateral tunnel) had complete occlusion of the fenestration on echocardiography. There was no immediate or late complication. Transcatheter closure of fenestration in Fontan operation using the Cook detachable coil is a safe and feasible technique. However, the coil was ineffective for closure of a punch-hole fenestration in the lateral tunnel type operation. In the conduit type fenestration, some modification of fenestration method instead of a short conduit for coil closure or use of new device is necessary to increase complete closure rate.

Effects of metallic implants on magnetic resonance imaging evaluation of Fontan palliation

This study examined the effects of endovascular metallic implants on the ability of magnetic resonance imaging to evaluate cardiovascular anatomy and to assess ventricular size and function in 101 consecutive patients with Fontan palliation. Compared with studies in patients without implants, in whom 100% of anatomic segments were adequately visualized and the median image quality grade for ventricular function assessment was 5 of 5, the presence of any implant (54% of studies) reduced the proportion of adequately imaged anatomy to 77% (p <0.001) and the median image quality grade for ventricular function assessment to 3 of 5 (p <0.001).

Percutaneous fenestration closure with problematic residual native atrial septum

A variety of techniques have been utilized to close Fontan fenestrations. Among 20 patients who underwent a cardiac catheterization for fenestration closure, 3 patients had residual native atrial septum, forming an additional intermediate chamber on the pulmonary venous side of the fenestration. Three different methods were used to close these fenestrations.

A novel implantation technique for closure of an atypical fenestration connecting the right atrial appendage to an extracardiac conduit by use of a 15 mm Helex device in a patient with total cavopulmonary connection

We report on a 7-years old patient after total cavopulmonary anastomosis with an extracardiac conduit. An atypical fenestration was created during the operation connecting the right atrial appendage to the extracardiac conduit. Because of arterial desaturation, the fenestration connecting the anterior wall of the extracardiac conduit to the posterior wall of the right atrial appendage was successfully occluded with a 15 mm Helex device by use of a modified implantation technique.

Diverse experience with the CardioSEAL and STARFlex septal occluders

Apart from closure of atrial septal defects, there is little information concerning the use of the CardioSEAL family of occluders in congenitally malformed hearts. We review here our initial experience using the CardioSEAL and STARFlex occluders in 12 patients aged 17.3 +/- 11.2 years, with a range from 4 to 34 years. Of the patients, 5 had fenestrated extracardiac Fontan procedures, 5 had persistent patency of the arterial duct, 1 had a leak across a Mustard baffle, and the final patient had a huge pulmonary arteriovenous malformation. We implanted successfully 9 CardioSEAL, and 3 STARFlex occluders, with sizes from 17 to 40 mm. In one patient, the occluder embolized to the right pulmonary artery, from where it was retrieved through the catheter. In two patients, there was a trivial residual leak immediately after implantation, but no patient had a residual leak after 6 months of follow-up. We noted improved ventricular dimensions, without any fractures of the arms of the occluders, perforations, or disturbances of flow after 2.4 +/- 0.9 years of follow-up. We have demonstrated, therefore, the versatility of the CardioSEAL and STARFlex occluders, which have been used safely and effectively to close a variety of intra and extracardiac communications other than atrial septal defects.

Transcatheter closure of atrial septal defects in children with a hypoplastic right ventricle

The efficacy and safety of device closure of atrial defects in children with complex congenital heart disease and a hypoplastic right ventricle have not been detailed. The objective of this study was to determine the clinical impact and outcomes of a staged surgical catheter-based management strategy. A retrospective analysis of 17 children with a hypoplastic right ventricle who had undergone cardiac catheterization and attempted device occlusion of an atrial defect was undertaken. Clinical data, anatomical diagnoses, previous surgeries, and interventions were noted. The clinical course and echocardiographic findings were compared before and after defect closure (6 +/- 4 months of follow-up). Nine children had pulmonary atresia with an intact ventricular septum, six had Ebstein's anomaly of the tricuspid valve, and two had isolated right ventricular hypoplasia. The mean age at defect closure was 6.6 +/- 3.4 years. Under general anesthesia, closure of the atrial defect was undertaken after initial temporary test occlusion. The Qp:Qs ratio before closure was 1.1 +/- 0.4. Oxygen saturation improved in all children from 91% +/- 1% to 98% +/- 1% (P < 0.0005). Mean right atrial pressure increased from 9 +/- 3 to 11 +/- 4 mm Hg after closure, but the difference was not statistically significant (P = 0.2). Follow-up revealed an increased right ventricular length (P = 0.009) and Z-score (P = 0.02), although no significant increase in the diameter of the tricuspid valve annulus was observed in children with pulmonary atresia. Right ventricular systolic pressures or systolic function did not change significantly during follow-up (P = 0.5 and 0.29, respectively). Exercise tolerance improved in all children and clinical evidence of right ventricular decompensation was absent. Catheter closure of atrial defects in children with a hypoplastic right ventricle is well tolerated, safe, and effective as a treatment strategy in the staged management.

Clipped tube fenestration after extracardiac Fontan allows for simple transcatheter coil occlusion

BACKGROUND

Expensive devices are increasingly used to close a patent fenestration after a modified Fontan operation. We report our 5-year institutional experience of clipped tube fenestration after extracardiac Fontan operation, which allows for simple transcatheter coil occlusion.

METHODS

We retrospectively reviewed 30 children, median age of 4.0 years (range, 2.4 to 8.8 years) who underwent extracardiac Fontan operation between May 1996 and May 2001, and were fenestrated using a 4- to 8-mm diameter clipped tube graft.

RESULTS

Ten children had a patent fenestration occluded by transcatheter placement of 15 detachable coils (5- to 8-mm diameter). Aortic oxygen saturations increased on average by 5.5% (2% to 14%) and mean pressures in the Fontan circuit by 2.5 mm Hg (0 to 3 mm Hg). Four had immediate complete occlusion angiographically and 6 had trivial residual shunt, but complete occlusion by echocardiography at follow-up. There have been no immediate complications, late coil embolizations, thromboembolic events, or documented hemolysis within a follow-up after coil implantation of 1.7 years (0.4 to 4.5 years). Spontaneous fenestration closure was documented in 8 patients at cardiac catheterization and 9 patients by echocardiography with consistent improvement in resting transcutaneous oxygen saturation. Two children with a patent fenestration have been considered inappropriate for closure, and there was one early surgical death. There have been no complications related to the tube fenestration modification within a follow-up postoperation of 2.6 years (0.1 to 5.5 years).

CONCLUSIONS

Clipped tube fenestration after extracardiac Fontan operation is a useful surgical modification that allows for simple transcatheter coil occlusion.

Pediatric cardiac catheterization

The publications of 2000 and 2001 stress how interventional pediatric cardiology has moved from angioplasty to device placement. This review summarizes the important articles during the past year that evaluated the safety and efficacy of atrial septal defect devices, patent ductus occluders, and stents to treat coarctation of the aorta. The past year has also seen the emergence of old technologies that have been modified and expanded for new applications. The three areas of old technology reviewed are (1) using balloon angioplasty to palliate low birth weight infants with critical coarctation, (2) using coronary interventions in the pediatric patient, and (3) using balloon pulmonary angioplasty to treat patients with chronic thromboembolic pulmonary hypertension. Finally, this review describes the development of a new interventional technique, transcatheter implantation of a pulmonary valve, and outlines how real-time MRI in the next decade likely will replace x-ray fluoroscopy as the primary diagnostic and interventional imaging tool for the pediatric cardiologist.

Catheter interventions in adult patients with congenital heart disease

Adult patients with congenital heart disease provide a wide variety of challenges for the interventional cardiologist. Procedures can broadly be divided into dilatation or closure. The most common interventions in our own practice are closure of atrial septal defects and patent foramen ovale, although closure of postoperative interatrial communications in Mustard, Senning, or Fontan patients is also possible. Transcatheter patent ductus arteriosus closure is also now routine, and occlusion of coronary artery fistulae can be safely attempted using coil embolisation. Balloon dilatation of pulmonary valve stenosis has excellent success rates, and dilatation or stenting of pulmonary artery stenoses is also beneficial in selected cases. Although aortic valve dilatation in adults has mixed results, dilatation or stenting of aortic coarctation is now becoming more widespread, and has promising results. Dilatation procedures may also be applicable to the postoperative patient with conduit or baffle stenosis.