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permit safe entry; and (3) facilitate insertion, since direct visualization generally allows the probe to be passed during a single attempt. In addition to the risks of pharyngeal and esophageal trauma during probe insertion, a recent report8 points out the potential for airway obstruction and cardiovascular compromise when large transesophageal probes are used in small children and stresses the use of small probes in this population. We also use this direct visualization technique to achieve first-pass atraumatic intraoperative placement of the adult probe in children who weigh 20 kg or more and in adults. Nonvisually directed techniques for intraoperative probe insertion have been described in adults6, 7 and used with or without modification in children.le4 In this approach, visually directed probe insertion with the use of a laryngoscope is reserved for patients in whom nonvisually directed insertion is difficult

1>4,% 7

The esophageal stethoscope has not been a problem in infants that weigh as little as 5.1 kg because it leaves enough room in the esophagus for the transesophageal probe. In the smaller infant or neonate, it may be necessary to remove the esophageal stethoscope after direct visualization of its pathway to allow insertion of the probe via this pathway. There are smaller pediatric probesi-s (e.g., 6.8 mm tip), available for introduction in smaller babies than the probe that we used. The esophageal stethoscope has generally not interfered with contact between probe and esophagus or with image acquisition. If esophageal stethoscope monitoring is not used, an orogastric or nasogastric tube may be substituted to establish the esophageal pathway. REFERENCES

1. Ritter SB. Transesophageal real-time echocardiography in infants and children with congenital heart disease.J Am Co11 Cardiol 1991;1&569-80. 2. Muhiudeen IA, Roberson DA, Silverman NH, Haas GS,Turley K, Cahalan MK. Intraoperative echocardiography for evaluation of congenital heart defects in infants and children. Anesthesiology1992;76:165-72. 3, Fyfe DA, Kline CH, Sade RM, Greene CA, Gillette PC. The utility

of transesophageal

echocardiography

during

and

after

Fontan ooerations in small children. AM HEART J 1991; 122:i403-i5. 4. Stumper 0, Kaulitz R, ElzengaNJ, Born N, Roelandt JRTC, Hess J, Sutherland GR. The value of transesophageal echocardiography in children with congenital heart disease. J Am Sot Echo 1991;4:164-76. Sorensen GK, Stevenson, JG. Pediatric transesophageal echo: an evaluation of the feasibility and utility in 129 examinations [Abstract]. Anesthesiology 1991;75(3A):A391. Seward JB, Khandheria BK, Oh JK, Abel MD, Hughes RW! Edwards WD, Nichols BA, Freeman WK, Tajik AJ. Transesophageal echocardiography: technique, anatomic correlations, implementation, and clinical applications. Mayo Clin

Proc 198&63:649-80.

Clements FM, de Bruijn NP. Transesophageal echocardiography. Boston: Little, Brown and Company, 1991:67-72. Gilbert TB, Panic0 FG, McGill WA, Martin GR, Halley DG, Sell JE. Bronchial obstruction by transesophageal echocardiography probe in a pediatric cardiac patient. Anesth Analg 1992:74:156-8.

November 1992 Heari Journal

Transient ischemic attacks after long-term clamshell occluder implantation for closure of atrial septal defect Kerry C. Prewitt, MD, Neal S. Gaither, MD, Andrew Farb, MD, and Dale C. Wortham, MD Washington,

D.C.

Transcatheter closure of cardiac defects has been possible for nearly 2 decades. Several different devices have been used to close a variety of cardiac defects.im4A clamshell oceluder has recently been developed by Bard (USC1 Angiographics, Tewksbury, Mass.) and has proven to be successful in the closure of atria1 and ventricular defects.” Pathologic evaluation of explanted clamshell occluders from human beings has not been reported. We report the case of an 1%year-old patient who began having transient ischemic attacks after transcatheter closure of an atria1 septal defect (ASD) with the Bard clamshell occluder. The occluder was subsequently removed and pathologic evaluation was done. An 18-year-old woman was seen for follow-up evaluation of patent ductus arteriosus ligation and ventricular septal defect repair at 18 months of age. A patent foramen ovale and mild pulmonary artery branch stenosis were noted at that time. In the interim, the patient was free of symptoms. Evaluation at 18 years of age with transesophageal echocardiography showed a secundum ASD with evidence of bidirectional shunting. Cardiac catheterization revealed a left-to-right shunt with a Qp to Qs ratio of 1.3:l and mild pulmonary branch stenosis. A 12 mm secundum ASD was documented by angiography. The ASD was believed to be of moderate size; however, the left-to-right shunt was limited and may have been affected by right ventricular compliance. The patient underwent uncomplicated transcatheter closure of the ASD with the Bard clamshell occluder and standard technique.6 The ASD size was estimated to be 12 to 13 mm with the use of a sizing balloon; a 28 mm occluder was placed. Right atria1 angiography after oceluder placement showed a small leak across the atria1 septum. The patient began taking aspirin and did well, but at the time of the 6-month follow-up examination she reported 3 weeks of recurrent right and left homonymous hemianopia of several hours duration without other neuro-

From the Cardiology Service, Walter Reed Army Medical Center and the Department of Cardiovascular Pathology, Armed Forces Institute of Pathology, Washington, D. C. The opinions expressed are those of the authors and ars not to be ccmstrued as official or as reflecting the views of the Department of the Army CI~the Department of Defense. Reprint requests: Kerry C. Prewitt, MD, Cardiology Service, Walter Reed Army Medical Center, Washington, DC 20307.5001. 4f4~40632

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1. Right atria1 surface of occluder. A, Focal thick fibrous tissue covering is seen (urrows). A small thrombus (urrowhead) is present. B, Scanning electron micrograph of occluder wire and adjacent mesh demonstrates partial endothelialization cej and exposed mesh (m). (b x 62.)

Fig.

logic symptoms. Complete neurologic evaluation including magnetic resonance imaging of the head was unremarkable. The transient ischemic attacks were new symptoms and were believed to be possibly related to the device. Transesophageal echocardiography showed a well-positioned device and bidirectional shunting. No thrombus was seen. The device was surgically removed intact, and the ASD was closed primarily at 7 months after implantation. Findings during surgery included an elongated slit-like ASD with a properly positioned device and a small residual ASD. At 6 months after surgery, the patient remained symptom-free. Pathologic evaluation was performed on the explanted clamshell occluder. From gross inspection, the wires of the device appeared to be intact without evidence of fractures. No defects were apparent within the meshwork. On the right atria1 side of the occluder (Fig. l), the wires were approximately 80 ‘% covered by tissue. The fabric was approximately 507 covered by tissue. At the center of the right atria1 surface, a fibrin thrombus that measured 0.2 cm at its greatest diameter was present. Scanning electron microscopy of the right side demonstrated that fabric and wires were partially covered by fibrin and endothelial cells. On the left atria1 surface (Fig. 2), a fibrous covering was present on approximately 20 % of the wires and 30 % of the fabric. The remaining wires and mesh were covered by a transparent film. A small thrombus was present at one edge. Scanning electron microscopy revealed large areas of

the fabric with intertwined fibrin strands with scattered erythrocytes and white blood cells; occasional endothelial cells were seen. Endothelialization was primarily present toward the periphery of the device and in fibrous areas. When present, endothelial cells demonstrated typical cobblestone arrangement in areas of the device that were covered with tissue. The Bard clamshell occluder has been available since 1989, when it was first used in a multicenter clinical trial to close atria1 defects. Preliminary data on complications after occluder placement in 400 patients include two cases of systemic emboli.7 There have been no occluder-related deaths. Recently asymptomatic strut fracture has been noted in approximately 20% of patients; this caused a temporary discontinuation of device implantations. Pathologic evaluation of occluder devices has been limited. Examination of a similar device, the Rashkind PDA occluder, (USCI, Inc., Billerica, Mass.) has been reported in four patients and five animals.‘, 3,* A fibrin-platelet infiltrate occurs in the first few days.s One occluder, which was studied at 12 months after implantation, was covered with endothelium except for two metal arm tips.Z Pathologic evaluation of the Bard clamshell occluder has been reported in only one lamb and showed complete endothelialization of the surface and enmeshment of the fabric with fibrous tissue.g This is the first reported case of development of new neurologic symptoms after Bard clamshell occluder place-

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November 1992 ,4rnenc?1” Heart Journal

Brief Communications

Fig. 2. Left atria1 surface of occluder. A, Thick fibrous tissue (arrows) part,ially covers wires and mesh. A thrombus is present at one edge (arrowhead). 6, Tissue as seen with scanning electron microscopy (X 150). cells, in C, Fibrin strands embedded in nonendothelialized mesh are seen (X 90). D, Confluent endothelial a cobblestone arrangement, surround a focus of exposed mesh (X 80).

ment and the first reported pathoIogic evaiuation of this type of occluder from a human being. This case demonstrates that long-term implantation of clamshell occluders may be associated with incomplete endothehalization and adherent thrombi. These findings are of concern and may be related to the transient ischemic attacks that were experienced by our patient. Further clinical and pathologic evaluation of this device is necessary.

REFERENCES

1, Rashkind WJ. Transcatheter treatment of congenital h eart disease. Circulation 1983;67:711-16. 2. Lock JE, Cockerham JT, Keane JF, Finley JP, Wakely PJ-G Fellows KE. Transcatheter umbrella closure of conger lital heart defects. Circulation 1987;75:593-9. 3, Lock JE, Block PC, McKay RG, Bairn DS, Keane JF. T ranscatheter closure of ventricular septal defects. Circula :&ion 1988;78z361-8.

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4. Sideris EB, Sideris SE, Fowlkes JP, Ehly RL, Smith JE, Gulde RE. Transvenoue atrial septal defect occlusion in pigleta with a “buttoned” double-disk device. Ciiculation 1990;81:312-18. 5. Rome JJ, Keane JF, Perry SB, Spevak PJ, Lock JE. Doubleumbrella closure of atrial defects. Circulation 19908~751-8. 6. Bridges ND, Perry SB, Keane JF, Goldstein SAN, Mandell V, Mayer JE, Jonas RA, Casteneda AR, Lock JE. Preoperative transcatheter closure of congenital muscular ventricular septal defects. N Enal J Med 1991;324zl312-17. 7. Latson LA, Benson LN, Hellenbrand WE, Mullin CE, Lock JE. Transcatheter closure of ASD-early results of multicenter trial of the Bard clamshell septal occluder [Abstract]. Circulation 1991;84(suppl 11):544. 8. Latson LA, Sobczyk WL, Kilter KL, McManus BM. Closure of atria1 septal defects with the Rashkind occluder: rapid loss of permeability [Abstract]. Circulation 1987;76(suppl IV):IV265. 9. Lock JE, Rome JJ, Davis R, Praagh SV, Perry SB, Praagh RV, Keane JF. Transcatheter closure of atria1 septal defects. Circulation 1989;791091-9.

Pseudoaneurysm of a saphenous vein coronary artery bypass graft with a fistula draining into the right atrium J. Wouter Jukema, MD, Paul R. M. van Dijkman, MD, and Ernst E. van der Wall, MD Leiden, ,The Netherlands

Aneurysmal dilatation and rupture of a vein graft with formation of a pseudoaneurysm are rare but well known complications of coronary artery bypass grafting (CABG).1-3 The development of a large pseudoaneurysm of a saphenous vein coronary artery bypass graft with a fistula that drains into the right atrium and results in a left-to-right shunt, has not been described before. This report describes a patient with this serious complication in whom the diagnosis could be made noninvasively by transesophageal echocardiography (TEE) in combination with magnetic resonance imaging (MRI). A 6%year-old woman was admitted to our hospital with a 3-month history of worsening exertional angina and shortness of breath. The patient had undergone CABG in 1984, and aortocoronary saphenous vein grafts had been placed on the right coronary artery and on the left anterior descending coronary artery. During surgery an acute myocardial infarction of the inferior wall developed. Routine postoperative coronary angiography revealed that both grafts were occluded at the origin. The patient refused to undergo repeat CABG and she was treated with pharmacologic therapy. For more than 6 years she had stable angina (New York Heart Association class II/IV). During the From the Department Netherlands.

of Cardiology,

University

Reprint requests: J. Wouter Jukema, MD, Building 1, C5-P, University Hospital Leiden, Leiden, The Netherlands. 414140455

Hospital

Leiden,

The

Department of Cardiology, Rijnsburgerweg lo,2333 AA

Fig. 1. Chest roentgenogram showing an abnormal rightsided cardiac contour (arrow).

few months before her admission she complained of progressive angina and exertional dyspnea in combination with a dry cough when she was lying on her right side. During physical examination, a systolic murmur that was due to mitral valve regurgitation was discovered. No diastolic murmur was heard. A chest roentgenogram (Fig. 1)

revealed an abnormal right-sided cardiac contour, which was not apparent on a previous chest roentgenogram 2 years before.

During

TEE

(Vingmed

Diasonics/Sonotron,

Zoetermeer, The Netherlands) a large cavity with a diameter of 7 x 10 cm was observed. It originated from the aortic root, 2 cm above the level of the origin of the native coronary arteries, and extended along the right side of the heart. The right atrium and right ventricle were compressed, which suggested high pressure in the abnormal cavity. Color-coded Doppler echocardiography showed a fistula

with continuous

flow from the abnormal

cavity into

the right atrium (Fig. 2). MRI (Gyroscan, 1.5 T, Philips Medical Systems, Best, The Netherlands) was performed with a spin-echo sequence; echo time was 30 msec and repetition time was equal to the R-R-interval. The three-dimensional nature of the abnormal cavity was clearly visualized. On the coronal images, the abnormal cavity extended from the aortic root, which is adjacent to the right atrium, to the diaphragm. a result of a chronic myocardial infarction, wall thinning

As of

the apex could be observed (Fig. 3, A). Transversal (Fig. 3, B) and sagittal oblique (Fig. 3, C) tine magnetic resonance images (echo time = 30 msec; repetition time = 40 msec; flip angle = 40 degrees)

showed a signal void in the abnor-