title: Influence of procedural differences on mitral valve configuration after surgical repair for functional mitral regurgitation: in which direction should the papillary muscle be relocated?
abstract: BACKGROUND
  After restrictive mitral annuloplasty (RMAP) for functional mitral regurgitation (MR), the MR frequently recurs. Papillary muscle relocation (PMR) should reduce the recurrence rate. We assessed the influence of procedural differences in PMR on the postoperative mitral valve configuration.
  
  
  METHODS
  Thirty-nine patients who underwent mitral valve repair for functional MR were enrolled. In limited tethering cases, RMAP alone was performed (RMAP group; n = 23). In severe tethering cases, in addition to RMAP, bilateral papillary muscles were relocated in the direction of the posterior annulus (posterior PMR group; n = 10) or anterior annulus (anterior PMR group; n = 6). We performed pre- and postoperative transthoracic echocardiographic studies, introducing a new index, mitral inflow angle (MIA), to assess the diastolic mitral leaflet excursion. MIA was measured as the angle between the mitral annular plane and the bisector of the anterior and posterior leaflets.
  
  
  RESULTS
  Postoperative MR grade was significantly reduced in each group (P < 0.001). Follow-up echocardiography showed recurrent MR in 13% of the patients in RMAP group. In contrast, no recurrent MR was observed in either the anterior PMR or the posterior PMR group. After surgery, MIA was significantly reduced in both the RMAP group (P < 0.01) and the posterior PMR group (P < 0.001), but was preserved in the anterior PMR group (NS). None of the postoperative variables showed any significant difference between the early and late postoperative phases.
  
  
  CONCLUSIONS
  In the surgical treatment of functional MR, a PMR procedure in addition to RMAP was effective in reducing systolic MR. However, mitral valve opening assessed by MIA was restricted even after RMAP alone. The restriction was severely augmented after additional posterior PMR, but was attenuated after additional anterior PMR. The papillary muscle should be relocated in the direction of the anterior annulus to preserve the diastolic opening of the mitral valve.
authors.affiliation: The Department of Cardiovascular Surgery, Tokyo Medical and Dental University Graduate School of Medical and Dental Sciences, 1-5-45 Yushima, Bunkyo-ku, Tokyo, Japan. twatanabe.cvsg@tmd.ac.jp.
authors.forename: Taiju
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: The Department of Cardiovascular Surgery, Tokyo Medical and Dental University Graduate School of Medical and Dental Sciences, 1-5-45 Yushima, Bunkyo-ku, Tokyo, Japan. hiro.cvsg@tmd.ac.jp.
authors.forename: Hirokuni
authors.initials: H
authors.lastname: Arai
authors.affiliation: The Department of Cardiovascular Surgery, Tokyo Medical and Dental University Graduate School of Medical and Dental Sciences, 1-5-45 Yushima, Bunkyo-ku, Tokyo, Japan. nagaoka.cvsg@tmd.ac.jp.
authors.forename: Eiki
authors.initials: E
authors.lastname: Nagaoka
authors.affiliation: The Department of Cardiovascular Surgery, Tokyo Medical and Dental University Graduate School of Medical and Dental Sciences, 1-5-45 Yushima, Bunkyo-ku, Tokyo, Japan. keijioi.cvsg@tmd.ac.jp.
authors.forename: Keiji
authors.initials: K
authors.lastname: Oi
authors.affiliation: The Department of Cardiovascular Surgery, Tokyo Medical and Dental University Graduate School of Medical and Dental Sciences, 1-5-45 Yushima, Bunkyo-ku, Tokyo, Japan. hachimaru.cvsg@tmd.ac.jp.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Hachimaru
authors.affiliation: The Department of Cardiovascular Surgery, Tokyo Medical and Dental University Graduate School of Medical and Dental Sciences, 1-5-45 Yushima, Bunkyo-ku, Tokyo, Japan. kuroki.cvsg@tmd.ac.jp.
authors.forename: Hidehito
authors.initials: H
authors.lastname: Kuroki
authors.affiliation: The Department of Cardiovascular Surgery, Tokyo Medical and Dental University Graduate School of Medical and Dental Sciences, 1-5-45 Yushima, Bunkyo-ku, Tokyo, Japan. tfujiwara.cvsg@tmd.ac.jp.
authors.forename: Tatsuki
authors.initials: T
authors.lastname: Fujiwara
authors.affiliation: The Department of Cardiovascular Surgery, Tokyo Medical and Dental University Graduate School of Medical and Dental Sciences, 1-5-45 Yushima, Bunkyo-ku, Tokyo, Japan. mizuno.cvsg@tmd.ac.jp.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Mizuno
mesh_terms: D006348:Cardiac Surgical Procedures / Q000379:methods*; D004452:Echocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000601:surgery*; D010210:Papillary Muscles / Q000601:surgery*; D011184:Postoperative Period; D012008:Recurrence; D013599:Systole