A New Amplatzer Device to Maintain Patency of Fontan Fenestrations and Atrial Septal Defects

Transcription

1 Catheterization and Cardiovascular Interventions 57: (2002) Pediatric Interventions A New Amplatzer Device to Maintain Patency of Fontan Fenestrations and Atrial Septal Defects Zahid Amin, 1,2 * MD, David A. Danford, 1,2 MD, and Carlos A.C. Pedra, 1,2 MD 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. Cathet Cardiovasc Intervent 2002;57: Wiley-Liss, Inc. Key words: Amplatzer device; Fontan fenestration; protein-losing enteropathy INTRODUCTION Patients with single-ventricle morphology need separation of the systemic venous and systemic arterial circulation. This is accomplished with a lateral tunnel or extracardiac Fontan operation. After the Fontan, loss of ventricular coupling and placement of the systemic venous and the pulmonary arterial circulation in series increases pressure in the systemic veins [1]. A surgically created fenestration between the systemic venous and pulomonary venous circulation tends to improve cardiac output at the expense of low systemic oxygen saturations [2]. Some surgically created fenestrations close spontaneously and lead to Fontan circulation failure [3]. Recent data suggest that creation of fenestration in Fontan patients with protein-losing enteropathy may improve the clinical condition of the patient [3,4]. Some patients with pulmonary hypertension or ventricular dysfunction may need a communication in the atrial septum for circulatory decompression [5]. In order to maintain long-term patency of the Fontan fenestration and desirable small atrial communication in other physiologic settings, we modified the Amplatzer septal occluder (ASO) to create a 4 mm fenestration through the disks. In this report, we describe the results of four patients who underwent placement of Amplatzer fenestrated device. CASE REPORTS Amplatzer Fenestrated Device The basic design of the device was similar to the ASO. The device was constructed from fine nitinol ( Joint Division of Pediatric Cardiology, University of Nebraska and Creighton University, Children s Hospital Omaha, Omaha, Nebraska 2 Instituto Dante Pazzanese de Cardiologia, Sao Paolo, Brazil *Correspondence to: Dr. Zahid Amin, Pediatric Cardiology, Children s Hospital, 8200 Dodge Street, 4th Floor, Health Care Pavilion, Omaha, NE zamin@chsomaha.org Received 12 November 2001; Revision accepted 21 May 2002 DOI /ccd Published online in Wiley InterScience ( Wiley-Liss, Inc.

2 Use of Amplatzer Fenestrated Device 247 Fig. 1. A: Amplatzer fenestrated device. The fenestration is clearly seen. B: Amplatzer fenestrated device, side view. A 12 Fr dilator has been introduced through the fenestration ) wires that were tightly woven into two disks with 4 mm connecting waist. The ends of the wire were welded to a platinum lug. The right atrial side of the disk had a microscrew for attachment to the delivery cable. A 4 mm tunnel was created through the disks and the waist of the device (Fig. 1). The tunnel was slightly oval rather than round because of the way the wire mesh was woven around the tunnel. The loading, delivery, deployment, and release mechanism were similar to the ASO. The device was custom-built for each of the patients, although the size of the waist can range from 4 to 40 mm. The size of the fenestration was 4 mm in all devices used in this study. The device is not approved by the FDA. All devices were placed under compassionate need basis after obtaining permission from Children s Hospital institutional review board, the Instituto Dante Pazzanese de Cardiologia, the AGA Medical Corporation, and FDA, on a case-by-case basis. Informed consent was obtained from the patient or guardian in all cases. Patient 1 This 8-year-old female was born with mitral atresia, multiple ventricular septal defects, and coarctation of the aorta. To prevent pulmonary edema from elevated pulmonary venous pressures, her restrictive interatrial communication was enlarged at age 9 days with balloon atrial septostomy. At 2 weeks of age, she underwent surgical repair of coarctation with concurrent banding of the pulmonary artery. Systemic cardiac output was dependent on flow through the ventricular septal defects, but these became progressively smaller, so at age 6 months, a Damus-Kaye-Stansel operation was performed to secure flow to the ascending aorta. At age 19 months, the single ventricular palliation was completed with a fenestrated lateral tunnel Fontan operation. The post-fontan course was complicated by chronic pleural effusions, and an infected fenestration snare, both of which ultimately resolved. At age 4.5, she presented with anasarca due to

3 248 Amin et al. hypoproteinemia (albumin, 2.5 mg/dl; total protein, 4.1 mg/dl). High gastrointestinal (GI) clearance of alpha-1- antitrypsin (85 ml/24 hr) confirmed the presence of protein-losing enteropathy (PLE). Cardiac catheterization revealed central venous pressure of mm Hg without distal obstruction to pulmonary blood flow. Only a small fenestration remained between the lateral tunnel and atrium proper. A small lateral tunnel fenestration was created in the cardiac catheterization laboratory. The new fenestration closed after a few months without demonstrable improvement in the PLE. Heparin therapy 4,000 6,000 U subcutaneously once daily was started but was discontinued 3.5 years into therapy due to osteopenia. More effective and long-lasting Fontan fenestration was sought in hopes of improving the PLE through decompression of the systemic venous system. Patient 2 This 3-year-old male was born with tricuspid atresia. Although no surgical management was undertaken in his native country (Belize) in infancy, progressive cyanosis prompted a trip to the United States for surgical palliation. Enroute to this country, he became somewhat dehydrated. Shortly after arrival, his systemic arterial oxygen saturations were 20% 30%, and hematocrit was 75%. He was emergently rehydrated and a 4.0 mm systemic to pulmonary arterial shunt was placed at age 35 months. Fourteen days later, definitive palliation was achieved with an extracardiac conduit Fontan operation with fenestration. He recovered well except for chronic pleural effusions that kept him hospitalized for the next 2.5 months. Cardiac catheterization 1 month after Fontan revealed spontaneous closure of the fenestration between extracardiac conduit and atrium proper. There was also mild pulmonary arterial branch stenosis, so balloon pulmonary arterioplasty was performed using a 10 mm 2 cm Tyshak balloon. When the pleural effusions failed to respond to the balloon pulmonary arterioplasty and to medical management with diuretics, digoxin, and captopril, transcatheter creation of a new fenestration was undertaken. Patient 3 This 3.5-year-old male was born with Barth syndrome, bicuspid aortic valve, and secundum atrial septal defect. Left ventricular dysfunction (shortening fraction 14%) was first noted echocardiographically at age 10 days. Treatment with furosemide and digoxin was initiated at that time, and later captopril and carnitine were added to the regimen. Left ventricular shortening fraction improved (23% 29% on multiple echocardiograms) in the first 3 years. He remained free from serious symptoms of congestive heart failure, so furosemide and captopril were successfully withdrawn after approximately 1 year. A mm secundum atrial septal defect with left-toright shunting was also noted, with progressive enlargement of the right atrium and ventricle. By the age of 36 months, the constellation of cardiomyopathy, cyclic neutropenia, growth retardation, developmental delays, and organic aciduria characteristic of Barth syndrome was fully appreciated. Nonsurgical management of the atrial septal defect was desired, but in view of his cardiomyopathy, his physicians were not certain that he would tolerate complete closure of the interatrial communication without unacceptable elevation of left atrial pressures. Transcatheter placement of a fenestrated atrial septal occluder was requested. Patient 4 This 12-year-old male underwent lateral tunnel Fontan procedure at 7 years of age for single ventricle. He developed hemidiaphragmatic paralysis after surgery. Over the last several years, he developed protein-losing enteropathy, which was confirmed by intestinal biopsy. Several medical regimens, including high doses of corticosteroids and heparin, were tried unsuccessfully. An echocardiogram demonstrated qualitatively good ventricular systolic function and mild diastolic dysfunction. Cardiac catheterization revealed high pressures in the Fontan circuit (mean, 18 mm Hg). His saturations were normal and pulmonary arteries were of good size with no distortion. No veno-venous or systemic-pulmonary collaterals were seen. A decision to create a fenestration and to place an Amplatzer fenestrated device was made. Procedure All procedures were performed under general anesthesia. Transesophageal echocardiography guidance was used in three patients. An angiogram was performed in the lateral tunnel to delineate the anatomy of the lateral tunnel or extracardiac conduit (Fig. 2A). After obtaining hemodynamic data, a transseptal needle was used to cross the medial wall of Gore-Tex patch (W.L. Gore, Flagstaff, AZ) lateral tunnel. In the patient with extracardiac conduit Fontan operation, the transseptal needle was used to traverse the Gore-Tex patch and the right atrial free wall. An Amplatz wire was introduced into the pulmonary venous atrium and over the wire and 8 mm 2 cm Z-Med II (B. Braun Medical, Bethlehem, PA) balloon was introduced and placed across the medial wall of the lateral tunnel. The balloon was inflated to dilate the Gore-Tex patch (Fig. 2B). Once the waist disappeared, the balloon was deflated and removed. The wire was left in place. A7FrAmplatzer delivery sheath (AGA Medical, Golden Valley, MN) was advanced over the wire and placed across the medial wall of the lateral tunnel,

4 Use of Amplatzer Fenestrated Device 249 Fig. 2. A: Angiogram in the lateral tunnel to delineate the anatomy of the lateral tunnel. No fenestration is seen. B: After perforating the Gore-Tex tunnel with a transseptal needle, an 8 mm balloon is used to dilate the fenestration in the Gore-Tex wall. C: The device has been deployed. A coronary wire is seen across the fenestration. D: A 4 mm coronary balloon is advanced across the fenestration and inflated to dilate the fenestration, if needed. E: Repeat angiogram in the lateral tunnel. Contrast is seen flowing across the fenestration into the pulmonary venous atrium.

5 250 Amin et al. TABLE I. Patient Data Systemic arterial saturations Systemic venous pressures Patient Predevice Postdevice Predevice Postdevice 1 94% 82% 17 mm Hg 15 mm Hg 2 95% 82% 17 mm Hg 15 mm Hg 4 95% 84% 18 mm Hg 14 mm Hg and the wire was removed. The Amplatzer fenestrated device (AGA Medical) was immersed in saline and screwed on to the delivery cable while immersed in saline. The device was loaded into the delivery sheath with the help of a loader. The device was advanced to the tip of the delivery sheath and deployed under transesophageal echocardiographic guidance, with the left disk in the pulmonary venous atrium and the right disk in the lateral tunnel or extracardiac conduit (Fig. 2C). After confirming excellent position of the device, the device was released. With the help of a glide catheter (Medi- Tech, Boston Scientific, Watertown, MA), a coronary wire (Microvena, White Bear Lake, MN) was introduced through the fenestration into the pulmonary venous atrium. A high-pressure coronary balloon was advanced over the wire and the fenestration was dilated to 4 mm in two patients and 5 mm in one patient with Sub-4 angioplasty balloon (Boston Scientific; Fig. 2D). A repeat angiogram was performed to confirm patent fenestration. In the patient with secundum ASD, the defect was measured with the help of Amplatzer sizing balloon (AGA Medical). The defect measured 16 mm. An 18 mm Amplatzer fenestrated device was deployed into the defect. This procedure was similar to deployment of Amplatzer septal occluder. The fenestration was not dilated after releasing the device. RESULTS The procedure was successful in all patients. In the Fontan patients, there was immediate drop in systemic arterial saturations and of systemic venous pressures after placement of the device in Fontan patients (Table I). Cineangiograms in the lateral tunnel and the extracardiac conduit revealed good flow through the device (Fig. 2E). Follow-up echocardiograms demonstrated continuous flow through the fenestration in all patients. In the patient with Amplatzer fenestration device in the atrial septal defect, the levophase demonstrated good flow through the fenestration. The pulmonary to systemic flow ratio decreased from 2.6:1 to 1.4:1. All patients showed improvements in hemodynamics over the next several months. Patients with PLE (patients 1 and 4) were taken off of heparin therapy for PLE. One year after device implantation, patient 1 s symptoms recurred. Cardiac catheterization performed after 1 year in this patient revealed wide-open fenestration with good right-to-left flow. Her systemic venous pressures were low (14 mm Hg). Follow-up in these patients ranges from 6 months to 1 year. All fenestration were patent by transthoracic echocardiograms at the last follow-up. DISCUSSION Creation of a fenestration in the lateral tunnel or extracardiac conduit is performed routinely in patients undergoing modified Fontan operation [6]. The cardiac output is maintained at the expense of lower saturations in times of increased systemic venous pressures. Fenestration also helps to keep the systemic venous pressures low, which is advantageous for the hepatic and splanchnic circulation [7]. Intraoperatively, a fenestration is usually created with the help of a 4 mm or larger punch or excision of the Gore-Tex patch. Some fenestrations are closed electively when the hemodynamics are stable and adequate cardiac output is demonstrated after temporary occlusion of the fenestration in the cardiac catheterization laboratory [8]. Some patients, however, require a patent fenestration to maintain cardiac output. Others, in whom a fenestration closed spontaneously or was never created during surgery, appear to benefit from creation of fenestration to improve cardiac output and to lower systemic venous pressures. These patients often manifest with protracted pleural effusions and develop proteinlosing enteropathy. Some reports have documented improvement in symptoms of PLE after creation of a fenestration [3]. In two of the three patients with Fontan operation described above, a fenestration was created during Fontan operation, but it closed spontaneously despite antiplatelet therapy. In one patient in this series, a fenestration was created in the catheterization laboratory, but without means to maintain long-term patency, it closed spontaneously after a few months. Instead of subjecting these patients to thoracic surgery and cardiopulmonary

6 Use of Amplatzer Fenestrated Device 251 bypass, we offered the procedure in the catheterization laboratory. Patient 3, who had device placed in the atrial septal defect, had Barth syndrome, as described above. There was some speculation that he may benefit from a small communication through the atrial septum. The device was successfully deployed in the atrial septal defect in a fashion similar to the Amplatzer septal occluder. Although the benefits of partial atrial septal occlusion in the setting of cardiomyopathy are debatable, there are other patients with atrial septal defects for whom the benefit of small residual defect are better established. For example, many patients have the diagnosis of atrial septal defect established later in life, after they develop pulmonary hypertension. These patients have negligible left-to-right flow (Qp:Qs 1:1), but on 100% supplemental oxygen they may show increased Qp:Qs ratio. Some of these patients have been shown to benefit from a small communication at the atrial level, which can act as a pop-off at the time of elevated pulmonary arterial pressures [5]. All patients were placed on daily aspirin therapy for antiplatelet effect after placement of the device. We recommend these patients should remain on antiplatelet therapy indefinitely. This is the first report that describes use of Amplatzer fenestration device in patients with lateral tunnel Fontan, extracardiac Fontan, and atrial septal defect. Amplatzer fenestration device was custom-built for all of these patients. Although the ASO is approved by the FDA, the Amplatzer fenestration device is not and is not under any Investigational Device Exempt protocol. Study Limitations The Amplatzer fenestration device was used in a limited number of patients, and the follow-up is limited. Therefore, the full range of technical problems with its delivery and acute function may not yet have been encountered. Furthermore, long-term adverse consequences of this device would not necessarily be detected by this investigation. Nevertheless, we believe that Amplatzer fenestration device is a valuable addition to the interventionalist s armamentarium. The biggest advantage of this device is in the symptomatic patients, who without the availability of this device would have been subjected to repeat sternotomy or multiple procedures in the catheterization laboratory. REFERENCES 1. de Leval MR. The Fontan circulation: what have we learned? what to expect? Pediatr Cardiol 1998;19: Mavroudis C, Zales V, Backer CL, Muster AJ, Latson LL. Fenestrated Fontan with delayed catheter closure. Circulation 1992; 86(Suppl II): Rychik J, Rome JJ, Jacobs ML. Late surgical fenestration for complications after Fontan operation. Circulation 1997;96: Rychik J. Management of protein-losing enteropathy after the Fontan operation. Semin Thorac Cardiovasc Surg Pediatr Cardiol Surg Ann 1998;1: Rich S, Dodin E, McLaughlin VV. Usefulness of atrial septostomy as a treatment for primary pulmonary hypertension and guidelines for its application. Am J Cardiol 1997;80: Airan B, Sharma R, Choudhary SK, Bhan A,Chowdhari UK, et al. Univentricular repair: is routine fenestration justified? Ann Thorac Surg 2000;69: Hsia TY, Khambadkone S, Redington AN, de Leval MR. Effect of fenestration on the sub-diaphragmatic venous hemodynamics in the total-cavopulmonary connection. Eur J Cardiothorac Surg 2001;19: Amin Z, Rocchini AP, Wax DF. Closure of residual shunts after Fontan operation with the Amplatzer occluder. Asian Cardiovasc Thorac Ann 1999;7: