Asian Cardiovasc Thorac Ann 2007;15:e55-e57
© 2007 Asia Publishing EXchange Ltd
Device Occlusion of Fontan Fenestration—an Economical Alternative
Rajasekaran Prem Sekar, MRCP,
Kotturathu M Cherian, FRACS1
The Department of Pediatric Cardiology
1 Cardiothoracic Surgery, International Center for Cardio Thoracic and Vascular Diseases, Chennai, India
For reprint information contact: Rajasekaran Prem Sekar, MRCP, Tel: 91 44 2656 7200, Fax: 91 44 2656 5150, Email: premsekar{at}yahoo.com, The Department of Pediatric Cardiology, International Center for Cardio Thoracic and Vascular Diseases, R-30-C Ambattur Industrial Estate Road, Mogappair, Chennai 600101, India.
 |
ABSTRACT
|
|---|
Fenestrating the Fontan circuit during total cavopulmonary anastomosis is commonly performed to reduce postoperative mortality and morbidity. The resulting systemic desaturation may progressively increase leading to symptoms. We report the case of a symptomatic eight year old, whose Fontan circuit fenestration was closed using a patent ductus arteriosus occluder. The marked improvement in the patient’s clinical status immediately and after 3 months confirms this device to be a safe, and economically better alternative to the atrial septal defect occluder.
|
INTRODUCTION
|
|---|
Fontan surgery, as the widely accepted palliation for single ventricle physiology, has evolved over a period of years to its current form of lateral tunnel and the subsequent extra cardiac Fontan. While total cavopulmonary anastomosis (TCPC) by septating the right atrium (RA) to create a lateral tunnel Fontan is advantageous in terms of ease of creation and inherent growth potential, one of the significant disadvantages is gradual dilatation of the septated right atrium with consequent loss of laminar flow and increasing pressure in the circuit.1 Fenestrating the Fontan circuit improves the short-term outcome not only in the high risk group but also in standard risk patients, by decreasing pleural drainage, hospital length of stay, and need for additional postoperative procedures.2
Occasionally, the resulting systemic desaturation may gradually progress with increasing Fontan circuit pressure making the patient symptomatic with progressive cyanosis and polycythemia. In such circumstances, the fenestration is commonly closed using coils for small fenestrations and small atrial septal defect (ASD) occluders for larger defects. We report the successful use of a Blockaid patent ductus arteriosus (PDA) occluder to close a large fenestration in a symptomatic child.
|
CASE REPORT
|
|---|
As an infant, the patient was diagnosed with double outlet right ventricle (DORV), L-loop ventricles, and D-malposed aorta with severe valvar and subpulmonary obstruction by echocardiography. As the small size of the LV and grade IV straddling of tricuspid valve precluded a complete repair, the infant underwent a Blalock Taussig shunt placement between the right innominate and the right pulmonary artery, using a 4 mm Goretex tube at the age of 10 months. Subsequently, at 4 years of age, he underwent a single stage lateral tunnel Fontan with a 4 mm fenestration, transection of main pulmonary artery and take down of the BT shunt. Six years later, the child presented with moderate cyanosis, clubbing, and effort intolerance (NYHA class II).
Investigations revealed a hemoglobin (Hb) level of 19.8 gm·dL–1, hematocrit of 58%, and peripheral saturation of 72% in room air. Transthoracic echocardiography revealed a mildly dilated lateral tunnel with significant fenestration shunt with a Doppler pressure gradient across it of 5 mm Hg indicating a satisfactory transpulmonary gradient. In view of the findings, it was decided to occlude the fenestration if tolerated.
Under ketamine sedation, bilateral femoral venous access and right femoral arterial access was established percutaneously and a lateral tunnel angiography was performed. This revealed a significant shunt across the fenestration in to the systemic circulation with very poor opacification of the pulmonary circuit (Figure 1
). The lateral tunnel mean pressure was 6 mm Hg. The fenestration was crossed with a 10 mm peripheral balloon catheter. The maximum diameter of the fenestration with balloon inflation was noted to be 7 mm. The fenestration was crossed with an 8 Fr device delivery sheath with dilator and the tip positioned in the atrium well beyond the septation. The dilator was withdrawn, the sheath aspirated and the position confirmed by hand injection of contrast dye and fluoroscopy.
View larger version (38K):
[in this window]
[in a new window]
|
Figure 1. Angiogram in the lateral tunnel in anteroposterior view demonstrating shunt (arrow) through the fenestration in to the heart. Note the absence of opacification of pulmonary arteries.
|
|
A 12/10 mm Blockaid PDA occluder (Shanghai Shape Memory Alloy Company Ltd., Shanghai, China) was introduced through the sheath after attaching it to a delivery wire and deployed across the fenestration. However, the device was found to be highly unstable, embolizing across the fenestration into the heart with even trivial movement of the attached delivery wire. The device was therefore withdrawn and a 14/12 mm Blockaid PDA occluder deployed across the fenestration with good stability. With the device still secured to the delivery wire, an angiogram in the lateral tunnel revealed complete abolition of the fenestration shunt and good opacification of the pulmonary arterial system (Figure 2). The peripheral saturation in room air immediately increased from 72% to 97% and the lateral tunnel mean pressure increased marginally to stabilize at 8 mm Hg. The device was then released and fluoroscopy in the lateral view confirmed stable and satisfactory positioning of the device (Figure 3) with trivial shunt through the body of the device noted on subsequent echocardiography.
View larger version (42K):
[in this window]
[in a new window]
|
Figure 2. Lateral tunnel angiogram in AP view revealing no shunt across the fenestration and enhanced flow to the pulmonary arteries.
|
|
View larger version (38K):
[in this window]
[in a new window]
|
Figure 3. Lateral view showing PDA occluder in position across the fenestration in the lateral tunnel. Flaring of the proximal end indicates that the device is not likely to migrate.
|
|
The child was discharged on aspirin 75 mg once daily. At 3 months follow-up, the child continued to maintain a saturation of 96% in room air. His serum Hb was 14 gm·dL–1, hematocrit was 45%, and serum protein levels were normal. Echocardiography revealed the device to be free of clots with no shunt across it. There were no ascites or peripheral edema and the patient reported improved exercise tolerance.
|
DISCUSSION
|
|---|
Occlusion of the fenestration in the Fontan circuit is carried out to reduce the risk of paradoxical embolus, and also to improve the systemic saturation by abolishing the right to left shunt. This is routinely done by nonsurgical interventional procedures. Various modalities have been described, coil embolization of the fenestration3 and occlusion using an ASD closure device4 being more common. Smaller fenestrations are amenable to successful embolization with either single or multiple coils. However, larger fenestrations (> 4 mm) are better occluded using occluder devices as this limits the risk of embolization and residual shunts associated with the use of multiple coils. The smaller sized ASD occluder is well suited for such purpose offering easy deployability and stability owing to the presence of two circular discs with a connecting smaller waist. The cost, however, is significantly higher than for coils and therefore limits use in a health system where the patient bears the total expenditure. Using an Amplatzer PDA occluder for this purpose has been reported.5 The use of a Blockaid PDA occluder in this child confirms it to be a safe alternative for occluding large fenestrations as well as an economically attractive option as the occluder and the delivery sheath together are available for approximately US $1355.
Choosing a device with a body diameter 4–5 mm bigger than the maximum fenestration width appears to favor increased stability, probably due to a combination of increased radial force against the fenestration wall exerted by the larger device along with the flaring of the proximal end of the device once deployed. The disparity in size of the fenestration as reported in the surgical notes (4 mm) and the actual balloon sizing (7 mm) was attributed to the stretch effect of the tissue. A trial balloon occlusion of the fenestration to confirm that there are no hemodynamic disturbances ensures smooth post-procedure recovery without the risk of ascites, peripheral edema, and secondary protein-losing enteropathy.
|
REFERENCES
|
|---|
- Galantowicz M, Cheatham JP. Fontan completion without surgery. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu 2004:7;48–55.[Medline]
- Lemler MS, Scott WA, Leonard SR, Stromberg D, Ramaciotti C. Fenestration improves clinical outcome of the fontan procedure: a prospective, randomized study. Circulation 2002;105:207–12.[Abstract/Free Full Text]
- Bradley TJ, Human DG, Culham JA, Duncan WJ, Patterson MW, LeBlanc JG, et al. Clipped tube fenestration after extracardiac Fontan allows for simple transcatheter coil occlusion. Ann Thorac Surg 2003;76:1923–8.[Abstract/Free Full Text]
- Alva C, David F, Ortegon J, Sanchez A, Lopez D, Ledesma M. Transcatheter closure of secundum atrial septal defects and fenestrated Fontan using the Amplatzer septal occluder. Initial prospective study. Arch Cardiol Mex 2003;73:185–9.[Medline]
- Rueda F, Squitieri C, Ballerini L. Closure of the fenestration in the extracardiac Fontan with the Amplatzer duct occluder device. Catheter Cardiovasc Interv 2001;54:88–92.[Medline]
TOP
ABSTRACT
INTRODUCTION
