CASE REPORT Tangential Triangular Resection An Option to Treat the Giant Left Atrium Pablo M. A. Pomerantzeff, MD, PhD, Carlos M. A. Branda ˜o, MD, Marco A. V. Guedes, MD, and Noedir A. G. Stolf, MD, PhD Abstract: A 21-year-old woman presented with congestive heart failure caused by congenital mitral and tricuspid insufficiency, associated with great left atrium enlargement. Transthoracic echo- cardiogram revealed heart dextroversion associated with mitral and tricuspid severe insufficiency and left atrium enlargement (14 cm), confirmed by magnetic resonance study. The left atrium was reduced by a tangential triangular resection of the posterior wall, between the pulmonary veins, suturing the edges of the left atrium with bovine pericardium strip reinforcement. Mitral and tricuspid valves were repaired. The postoperative course was uneventful, and the patient was discharged in the 15th postoperative day. A control magnetic resonance study revealed a 50% reduction in left atrium size. Evolution of left atrium resection is excellent, with low recurrence of arrhythmias, embolism, or heart failure. Key Words: Valve, Left atrium, Aneurysm. (Innovations 2010;5:125–127) L eft atrium aneurysm is a rare cardiac anomaly that was initially described by Semans and Taussig in 1939. 1 There are few reports in the literature, most of them related to left atrial appendage. Giant left atrium may be congenital or acquired. Sur- gical resection is the treatment of choice, even in asymptom- atic patients, because of the risks of rupture, systemic embo- lism, heart failure, arrhythmia, or extrinsic compression of trachea or esophagus. 2,3 CASE REPORT This procedure was performed in a 21-year-old woman with congestive heart failure caused by congenital mitral and tricuspid insufficiency, associated with great left atrium en- largement. Chest roentgenogram demonstrated a large mass that occupied the inferior half of right chest associated with cardiac area enlargement. Transthoracic echocardiogram re- vealed heart dextroversion associated with mitral and tricus- pid severe insufficiency, left atrium enlargement (14 cm), and ejection fraction of 40%. The magnetic resonance study (Fig. 1) confirmed the diagnostic of giant left atrium (16 cm). After median sternotomy, a giant left atrium was visu- alized posterolaterally, with rotation of the left ventricle border, wish was prominent and anterior in the pericardium. Under cardiopulmonary bypass, moderate hypothermia, and cardioplegic cardiac arrest, the left atrium was opened in a standard left atriotomy. The mitral valve was visualized, and mitral valve repair was performed by cleft closure associated with posterior pericardial strip annuloplasty. Then, the left atrium was reduced by a tangential triangular resection of the posterior wall, between the pulmonary veins, to avoid ana- tomic distortion of mitral annulus and pulmonary veins and, also, to reduce tension on the suture line (Fig. 2). The edges of the left atrium were sutured with bovine pericardium strip reinforcement, because of the friability of the atrial tissue. Tricuspid valve repair was performed by cleft closure and valve bicuspidization through a standard right atriotomy. The postoperative course was uneventful, and the pa- tient was discharged in the 15th postoperative day. A control magnetic resonance study, performed 6 months postopera- tively, revealed a 50% reduction in left atrium size (Fig. 3) and no mitral or tricuspid valve residual insufficiency. COMMENTS Surgical reduction of the left atrium was performed by single plication for many years, but this technique usually presents unsatisfactory atrial reduction. This fact has an impor- tant impact, because left atrium size is an independent predictor of mortality and morbidity in patients submitted to mitral valve surgery. 4 Some techniques of left atrial reduction were proposed in the literature, such as partial autotransplantation, devel- oped by Lessana et al. 5 We think that this approach can present higher operative morbidity because of higher cardio- pulmonary bypass time and more suture lines. There is no standard operative technique to reduce the left atrium size. The principles of left atrium aneurys- mectomy were resection and reconstruction without dis- tortion of mitral valve anatomy and pulmonary veins outflow. In this case, we performed a tangential triangular Accepted for publication February 8, 2010. From the Department of Cardiothoracic Surgery, Heart Institute, University of Sa ˜o Paulo Medical School, Sa ˜o Paulo, Brazil. Address correspondence and reprint requests to Pablo M. A. Pomerantzeff, MD, PhD, Heart Institute, University of Sa ˜o Paulo Medical School, Av. Dr. Ene ´as de Carvalho Aguiar, 44, Cerqueira Ce ´sar—CEP: 05403-000, Sa ˜o Paulo, Brazil. E-mail: dcipablo@incor.usp.br. Copyright © 2010 by the International Society for Minimally Invasive Cardiothoracic Surgery ISSN: 1556-9845/10/0502-0125 Innovations • Volume 5, Number 2, March/April 2010 125