Ann Thorac Surg 2008;85:643-645. doi:10.1016/j.athoracsur.2007.08.070
© 2008 The Society of Thoracic Surgeons
Case Reports
Transatrial Repair of Submitral Left Ventricular Pseudoaneurysm
Takashi Miura, MD*,
Kenji Yamazaki, MD,
Shinichiro Kihara, MD,
Satoshi Saito, MD,
Masayuki Miyagishima, MD,
Shigeyuki Aomi, MD,
Hiromi Kurosawa, MD
Department of Cardiovascular Surgery, The Heart Institute of Japan, Tokyo Women’s Medical University, Tokyo, Japan
Accepted for publication August 14, 2007.
* Address correspondence to Dr Miura, Department of Cardiovascular Surgery, The Heart Institute of Japan, Tokyo Women’s Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan (Email: takashiren{at}yahoo.co.jp).
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Abstract
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In a 57-year-old man with Wolff-Parkinson-White syndrome, a left ventricular pseudoaneurysm developed, induced by the pop phenomenon, after radiofrequency catheter ablation of the posterolateral accessory pathway. The pseudoaneurysm was positioned at the atrioventricular groove with moderate pericardial adhesions, and the rupture site was located just below the P3 annulus of the posterior mitral leaflet. With this anatomy and in the presence of adhesions, we repaired the rupture site from within the heart through an incision made in the posterior mitral leaflet. This transmitral approach might be a reasonable surgical option for treating this type of submitral left ventricular pseudoaneurysm.
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Introduction
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Submitral left ventricular (LV) pseudoaneurysm is a rare condition that can occur after inferior myocardial infarction or mitral valve replacement [1]. Submitral LV pseudoaneurysm induced by radiofrequency (RF) catheter ablation is exceedingly rare. The present report documents such an occurrence, and describes our experience with transatrial repair of the submitral LV pseudoaneurysm.
A 57-year-old man with Wolff-Parkinson-White syndrome was referred to us after RF catheter ablation owing to the development of a submitral LV pseudoaneurysm. The pseudoaneurysm was induced by the pop phenomenon during RF catheter ablation of the posterolateral accessory pathway. Computed tomography (CT) showed the pseudoaneurysm to be 15 x 15 mm in size and to be located on the posterior aspect of the left ventricle (Fig 1). Transesophageal echocardiography showed that the pseudoaneurysm was connected to the LV cavity and that the rupture site, which had a diameter of 4 mm, was just below the P3 annulus of the posterior mitral leaflet. Mitral regurgitation was not detected. The patient had two episodes of cardiogenic shock caused by the cardiac tamponade that resulted from rupture of the pseudoaneurysm. The first cardiogenic shock was treated successfully by pericardiocentesis. When cardiogenic shock recurred, however, an urgent operation was scheduled on the 23rd day after RF catheter ablation.
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Fig 1. Preoperative computed tomography showing that the pseudoaneurysm was located at the atrioventricular groove. (CV = coronary vein; LA = left atrium; LV = left ventricle.)
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After a midsternal incision and pericardiotomy, bloody pericardial fluid appeared. Moderate pericardial adhesions were present. Cardiopulmonary bypass was initiated with ascending aortic and bicaval cannulation. After cross clamping of the ascending aorta, a single dose of cold blood cardioplegia was injected into the aortic root. The mitral valve was accessed by a septal-superior incision. The surface of P3 was observed to show a reddish discoloration. However, the mitral complex was intact. An incision 15 mm in length was made in P3 parallel to its annulus to gain exposure to the rupture site. Through this opening, a 5-mm diameter rupture site of the left ventricle was seen just below the annulus of P3 (Fig 2A). The ventricular musculature surrounding this area was very fragile. Therefore, we closed it with three pairs of 3-0 Prolene mattress sutures (Ethicon, Somerville, NJ) supported by autopericardial strips. We also partially used the annulus of P3 for closing the rupture site. The strips of pericardium were used on each side of the aneurysm neck, and the neck was closed directly with these strips of pericardium (Fig 2B). The incision into P3 was closed with a 5-0 Ethibond running suture (Ethicon). The patient was weaned off the cardiopulmonary bypass without difficulty. Aortic cross-clamp and cardiopulmonary bypass times were 79 minutes and 164 minutes, respectively. An intraoperative transesophageal echocardiography showed the pseudoaneurysm was no longer connected to the LV cavity. However, mild mitral regurgitation from P3 was detected. A postoperative CT on the 14th day showed that the pseudoaneurysm was no longer present. The patient was discharged from the hospital in ambulatory condition on the 57th postoperative day after occupational rehabilitation. At the 1-year follow-up, transesophageal echocardiography showed the disappearance of the pseudoaneurysm. Mitral regurgitation had improved and could be classified as trivial.
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Fig 2. Intraoperative photographs. (A) A 5-mm diameter perforation site existed just below the posterior mitral annulus. (PL = posterior mitral leaflet; PS = perforation site.) (B) The perforation site was closed directly with three pairs of 3-0 polypropylene sutures and autopericardium.
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Comment
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In this case, the mechanism of occurrence of the submitral LV pseudoaneurysm was thought to be the pop phenomenon. This phenomenon is caused by an excess rise of temperature in the myocardium during RF catheter ablation. In this condition, steam forms and expands within the myocardium [2]. Subsequently, this causes a focal blast, and a crater is generated within the myocardium. This steam pop phenomenon is noted occasionally, and it can lead to perforation of the myocardium depending on the severity. Therefore, RF catheter ablation is most often performed in a temperature-controlled mode. However, the ablation electrode temperature is dependent on the opposing effects of heating from the tissue and cooling by the blood flowing around the electrode [3]. The ablation electrode temperature sometimes does not reflect the true temperature within the myocardium [4]. Therefore, there is the possibility of an excess rise of temperature within the myocardium. This phenomenon is an infrequent complication of RF catheter ablation, but can occasionally lead to critical myocardial rupture. Surgical treatment has been recognized as appropriate because pseudoaneurysms, unlike true aneurysms, are liable to fatal rupture [1]. Accordingly, we elected to carry out surgical treatment for this patient who had a history of two episodes of cardiac tamponade.
In the past, LV pseudoaneurysms after myocardial infarction have customarily been repaired through the free wall of the pseudoaneurysm, the so-called conventional ventricular approach [5]. However, this approach does not allow easy access to the posterior subvalvular area because of the variable direction of expansion of the pseudoaneurysm and the occurrence of pericardial adhesions. In two previous reports, Antunes and coworkers [6] and Jahangiri and colleagues [7] have utilized a transatrial approach to this repair. The Antunes transatrial approach was mainly performed on an African black population with congenital submitral LV true aneurysms located behind the left atrium. Antunes successfully directly closed the aneurysmal neck located below the posterior mitral annulus through an orifice created by an incision in the floor of the left atrium. On the other hand, Jahangiri and coworkers [7] reported a variation of the transatrial approach to a posterior submitral LV pseudoaneurysm that occurred after a myocardial infarction. Because the pseudoaneurysm was situated in a posterior and inferior location just below the posterior mitral leaflet and was accompanied by severe pericardial adhesions, Jahangiri approached the rupture site through the mitral orifice. He divided the posterior papillary muscle to gain exposure to the rupture site and successfully made a patch closure. The divided posterior papillary muscle was repaired without causing mitral regurgitation. Similar to the method used by Jahangiri, we approached the rupture site from within the heart because of the position of the pseudoaneurysm and the presence of moderate pericardial adhesions. The rupture site was easily closed through the opening obtained by an incision in the posterior mitral leaflet.
Trivial postoperative mitral regurgitation might result from distortion of the posterior mitral annulus when direct closure is employed. Wolpowitz and coworkers[8] reported the occurrence of postoperative mitral regurgitation necessitating mitral valve replacement after direct closure in the presence of a posterior subvalvular aneurysm. Accordingly, in such cases, we consider it appropriate to utilize application of a patch closure to avoid distortion of the mitral valve.
Although our experience is limited, this transatrial approach might be one of the surgical options for treating submitral LV pseudoaneurysm with pericardial adhesions.
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References
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- Frances C, Romero A, Grady D. Left ventricular pseudoaneurysm J Am Coll Cardiol 1998;32:557-561.[Medline]
- Dorwarth U, Fiek M, Remp T, et al. Radiofrequency catheter ablation: different cooled and noncooled electrode systems induce specific lesion geometries and adverse effects profiles Pacing Clin Electrophysiol 2003;26:1438-1445.[Medline]
- Yokoyama K, Nakagawa H, Wittkamp FH, Pitha JV, Lazzara R, Jackman WM. Comparison of electrode cooling between internal and open irrigation in radiofrequency ablation lesion depth and incidence of thrombus and steam pop Circulation 2006;113:11-19.[Abstract/Free Full Text]
- Tracy CM, Moore HJ, Solomon AJ, et al. Effective temperatures at sites of atrial insertion accessory pathway ablation [Abstract] J Am Coll Cardiol 1993;21:173A.
- Schrire V, Barnard CN. The surgical cure of a cardiac aneurysm of unknown cause J Cardiovasc Surg (Torino) 1963;4:5-10.[Medline]
- Antunes MJ. Submitral left ventricular aneurysmsCorrection by a new transatrial approach. J Thorac Cardiovasc Surg 1987;94:241-245.[Abstract]
- Jahangiri M, Sarkar D, Quinton P, Ward DE. Submitral left ventricular pseudoaneurysm Ann Thorac Surg 2005;79:1031-1032.[Abstract/Free Full Text]
- Wolpowitz A, Arman B, Barnard MS, Barnard CN. Annular subvalvular idiopathic left ventricular aneurysms in the black African Ann Thorac Surg 1979;27:350-355.[Abstract/Free Full Text]
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Abstract
Introduction
