Characteristics and treatment strategies of mitral regurgitation associated with undifferentiated papillary muscle

• Authors: Ichiro Matsumaru, Nagasaki University Hospital; Koji Hashizume, Nagasaki University Hospital; Tsuneo Ariyoshi, Nagasaki University Hospital; Kenta Izumi, Nagasaki University Hospital; Daisuke Onohara, Emory University; Shun Nakaji, Nagasaki University Hospital; Mizuki Sumi, Nagasaki University Hospital; Kiyoyuki Eishi, Nagasaki University Hospital; Akira Tsuneto, Nagasaki University; Tomayoshi Hayashi, Nagasaki University Hospital
• Journal Title: General Thoracic and Cardiovascular Surgery
• Volume: Volume 60, Number 7
• Publisher: Springer | 2012-07-01, Pages 406-410
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1007/s11748-012-0055-x
• Subjects: Health Sciences, Medicine and Surgery
• Keywords: Adolescent; Aged; Cell Differentiation; Chordae Tendineae; Female; Heart Defects, Congenital; Heart Valve Prosthesis Implantation; Humans; Japan; Male; Middle Aged; Mitral Valve; Mitral Valve Annuloplasty; Mitral Valve Insufficiency; Mitral Valve Prolapse; Papillary Muscles; Treatment Outcome; Ultrasonography

Abstract

Purpose: In this report we review our experience of operations on mitral regurgitation associated with abnormal papillary muscles/chordae tendineae of the mitral valves and discussed the clinical characteristics, operative findings, and treatment strategies. Methods: Undifferentiated papillary muscle was defined as a hypoplastic chordae tendineae with anomalous formation of papillary muscles attached to the mitral valves directly. Consecutive 87 patients undergoing surgery for mitral regurgitation at our institution were reviewed and 6 of them had undifferentiated papillary muscle. Results: The underlying mechanism of regurgitation was prolapse at the center of the anterior leaflet in 3 cases and tethering, a wide area of myxomatous degeneration, and annular dilatation in one case, respectively. Five patients underwent mitral valve plasty and 1 patient received replacement. Anomalous formation of chordae tendineae was corrected by resection and suture with transplantation at the tip of the leaflet to which abnormal chordae were attached in 2 cases, while resection and suture with chordal shortening was performed in 1 case, and chordal reconstruction using artificial chordae was employed in 2 cases. There was no operative death, and postoperative echocardiography showed no residual regurgitation in any of the cases. Conclusions: Mitral regurgitation associated with undifferentiated papillary muscle resulted from prolapse or tethering and impaired flexibility of leaflets. It was possible to successfully treat the patients by mitral valve plasty unless complex congenital cardiac malformation coexisted. Detailed examinations of attached papillary muscle by echocardiography and intraoperative inspection are necessary and surgical techniques should be selected appropriately in each case.