Ann Thorac Surg 1999;68:582-583
© 1999 The Society of Thoracic Surgeons
Case Reports
Transcatheter closure of a patent foramen ovale following mitral valve replacement
Ryszard Skulski, MDa,
John M. Snider, MDb,
Carol J. Buzzard, MDc,
Frederick S. Ling, MDa,
Alan M. Mendelsohn, MDc
a Division of Cardiology, Department of Medicine, Division of Cardiothoracic Surgery, University of Rochester Medical Center, Rochester>, New York, USA
b Department of Surgery, and Division of Pediatric Cardiology, University of Rochester Medical Center, Rochester>, New York, USA
c Department of Pediatrics, University of Rochester Medical Center, Rochester>, New York, USA
Address reprint requests to Dr Snider, Division of Cardiothoracic Surgery, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY 14642
e-mail: john_snider{at}urmc.rochester.edu
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Abstract
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We report the successful closure of a postoperative patent foramen ovale in a patient who underwent coronary artery bypass grafting and mitral valve replacement for severe mitral insufficiency. The postoperative course was complicated by severe hypoxemia due to a large patent foramen ovale. The patient underwent transcatheter closure with the Das Angel Wings transcatheter occluder (Microvena Corporation, White Bear Lake, MN) with immediate improvement.
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Introduction
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The management of atrial septal defects (ASD) detected following cardiac surgery has been observed for small, asymptomatic lesions and operative repair of symptomatic or hemodynamically significant defects. The percutaneous approach to ASD closure began in the 1970s [1]. Since 1996, the Das Angel Wings device (Microvena Corporation, White Bear Lake, MN) has been under FDA study for the treatment of ostium secundum ASD and patent foramen ovale (PFO). We report another indication for transcatheter PFO closure: a residual right to left shunt causing profound hypoxemia in a patient following coronary artery bypass surgery with mitral valve replacement.
A 71-year-old man presented with progressive exertional angina accompanied by dyspnea. Cardiopulmonary risk factors included severe obstructive and restrictive pulmonary disease. Physical examination before surgery was remarkable only for a grade III/VI holosystolic murmur at the apex.
A chest radiograph revealed findings consistent with chronic obstructive pulmonary disease. Echocardiography revealed mitral valve prolapse with severe mitral regurgitation. Right and left heart catheterization revealed severe mitral regurgitation, global left ventricular dyskinesis (EF 41%), and an 80% mid-left anterior descending stenosis, a 60% mid-circumflex stenosis, and diffuse right coronary artery disease. There was no detected step-up in oxygen saturation during hemodynamic study. Mean right atrial pressure was 6 mm Hg with a pulmonary capillary wedge pressure of 10 mm Hg. The patient underwent triple coronary artery bypass grafting. Inspection of the mitral valve through a posterior left atriotomy revealed myxomatous and prolapsing leaflets with rupture of two chordae of the posterior leaflet. The valve was replaced with a 31 mm St. Jude prosthesis (St. Jude Medical, Inc, St. Paul, MN) with preservation of the subvalvar apparatus. Initial intraoperative transesophageal echocardiography (TEE) revealed only trivial, residual mitral insufficiency. Following decannulation TEE suggested a PFO with bidirectional shunting. Due to a long bypass period and patient instability the PFO was not addressed.
The patient initially did well as he was quickly weaned from inotropic support and was extubated 10 hours postoperatively. He remained extubated for 60 hours but became hypoxic and required reintubation. Thereafter, the patient could not be weaned from mechanical ventilation, requiring 80%–100% inspired oxygen and eventual tracheostomy. Complications included pneumonia and atrial fibrillation. Bedside right heart catheterization (PaO2: left atrium 300 mm Hg, aorta 120 mm Hg, no step-up in right heart saturations) and TEE suggested a right to left shunt. Because of the patient’s condition, consideration was given to percutaneous closure of the PFO by transcatheter device occlusion using the Das Angel Wings device on a compassionate use basis. Following consultation with the trial’s corporate sponsor, Microvena Corporation (White Bear Lake, MN) and the Western Institutional Review Board, informed consent was obtained.
On the 24th postoperative day preimplantation studies were performed to determine the size of the defect, the degree of atrial shunting, and angiographic definition of the plane of the atrial septum. Bidirectional flow through the defect was confirmed by color Doppler and by oxygen saturations during the catheterization (PaO2: SVC 43 mm Hg, pulmonary artery 47 mm Hg, left atrium 300 mm Hg, femoral artery 140 mm Hg). The calculated left-to-right and right-to-left shunts were 1.05 L/min and 0.7 L/min respectively, significantly reducing the effective pulmonary blood flow to 3.0 L/min. The defect measured 8.6 mm x 12.5 mm. A Meditech (Boston Scientific, Watertown, MA) balloon occlusion catheter was used to balloon size the defect and confirmed the absence of an obligate right-to-left shunt. A 25 mm Das Angel Wings occluder was deployed under transesophageal guidance (Fig 1). The full description of device deployment is detailed elsewhere [2, 3]. In the femoral artery, PaO2increased (140 mm Hg to 300 mm Hg) but did not significantly change in the right atrium. Due to fears about device dislodgment, no post implantation pulmonary artery saturations were obtained. A post implantation angiogram revealed minimal residual shunting. Echocardiography 24 hours later revealed proper position of the device and no residual shunting. The patient was eventually weaned off artificial ventilation and was discharged 2 weeks following device implantation.
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Fig 1. Spot fluoroscopic image of deployed Das Angel Wings 25 mm ASD occlusion device. Note distance between occlusion device and St. Jude mitral valve. Large arrow indicates valve, small arrow indicates occlusion device.
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Comment
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The incidence of PFO in adults over 50-years-old is 25% [4]. In patients undergoing cardiovascular surgery, 22% have been found to have a PFO by intraoperative TEE [5]. Two serious sequelae of PFO are right-to-left shunting with hypoxemia and paradoxical embolization. Right-to-left shunting may occur with increased right atrial pressures acutely following cardiac surgery. However, it may also exist under normal hemodynamic conditions [6] or with respiratory maneuvers, such as valsalva or cough. At endsystole and early diastole, pressures in the right atrium may be higher than in the left atrium. In this patient, higher preoperative left atrial pressures due to mitral insufficiency might have reduced the significance of any interatrial right to left shunt that was then unmasked by reduction of the left atrial pressure by mitral valve replacement. Several reports describe right-to-left intracardiac shunts in patients with pulmonary embolization, right ventricular infarction, chronic obstructive lung disease, mechanical ventilation with positive end-expiratory pressure, cardiac tamponade, use of left ventricular assist device, and unilateral diaphragmatic paralysis [7, 8]. Knowledge of a PFO preoperatively would allow intraoperative closure and might alter surgical approach to the mitral valve (transeptal versus left atriotomy).
Previous reports have described the efficacy and safety of transcatheter closure of atrial septal defects; however there are few reports demonstrating the utility of transcatheter closure of interatrial communications following cardiac surgery. In our patient, persistent hypoxemia, infectious complications, and patient instability required a prompt and less invasive intervention. This report describes the treatment of post-surgical right-to-left shunting through a PFO using the Das Angel Wings occluder.
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References
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O’Laughlin M.P. Catheter closure of secundum atrial defects. Tex Heart Inst J 1997;24:287-292.[Medline]
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Das G.S., Voss G., Jarvis G., Wyche K., Gunther R., Wilson R. Experimental atrial septal defect closure with a new transcatheter, self-centering device. Circulation 1993;88(part 1):1754-1764.[Abstract/Free Full Text]
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Mendelsohn A.M., Banerjee A., Schwartz D.C., Das G.S. Transcatheter atrial septal defect closure with the Das Angel Wings transcatheter ASD occlusion device. J Intervent Cardiol 1998;11:495-500.
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Hagen P.T., Scholz D.G., Edwards W.D. Incidence and size of patent foramen ovale during the first 10 decades of life. Mayo Clin Proc 1994;58:17-20.
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Konstadt S.N., Louie E.K., Black S., Rao T.L., Scanlon P. Intraoperative detection of patent foramen ovale by transesophageal echocardiography. Anesthesiology 1991;74:212-216.[Medline]
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Strunk B.L., Cheitlin M.D., Stulbarg M.S., Schiller N.B. Right to left interatrial shunting through a patent foramen ovale despite normal intracardiac pressures. Am J Cardiol 1987;60:413-415.[Medline]
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Allan J.J., Marinelli C., Dellsperger K., Winniford M.D. Percutaneous balloon catheter closure of a patent foramen ovale in a patient with pulmonary disease, profound hypoxemia, and normal right heart pressures. Clin Cardiol 1997;20:307-309.[Medline]
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Baldwin RT, Duncan JM, Frazier OH, Wilansky S. PFO: a cause of hypoxemia in patients on left ventricular support. Ann Thorac Surg 1991;52:865–7.
Accepted for publication January 19, 1999.
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Abstract
Introduction
