The Challenge of Hammock Mitral Valve During Infancy: Precise Preoperative Advanced Imaging and Three-Dimensional Modeling Augments Customized Operative Valve Reconstruction

Abstract

Hammock mitral valve (MV), also known as anomalous mitral arcade, is a rare congenital anomaly. We report a case of a 10-month-old child who presented with congestive heart failure and was found to have severe mitral stenosis (MS) secondary to a hammock MV anomaly. Detailed advanced imaging with cardiac MRI and three-dimensional (3D) echocardiography favorably navigated a customized valve-sparing surgical reconstruction of the congenitally abnormal MV. Repair of a hammock MV is technically difficult with a guarded prognosis. Surgical experience is extremely limited and variable outcomes are reported. A rare case of severe MS secondary to hammock MV deformity with successful surgical repair and review of worldwide literature are presented.

Undifferentiated Chordae Tendineae of the Mitral Valve: Large Cohort Study of a Rare Mitral Malformation

“…However, some of our cases did not fit the classic mitral arcade pattern but comprised incomplete forms and appeared in a spectrum of undifferentiated chordae tendineae. Some mitral hemi-arcade and partial hammock MV have been reported in recent years (19,20), and some reported adult cases (21)(22)(23)(24)(25) support these findings. Accordingly, we proposed the concept of a spectrum of UCMV and classified it into three grades according to the involved chorda groups and presence or absence of MS.…”

“…The reported mitral hemi-arcade and partial hammock MV showed the same anatomical features ( 19 , 20 ). The anatomy of class I of UCMV and that of the parachute-like asymmetric MV proposed by Oosthoek ( 23 ) are extremely similar. The elongated anterolateral papillary muscle is connected with the leaflet directly or through the unusually short chordae, and the posteromedial papillary muscle is normal.…”

“…Though the structure of UCMV is more complex, the same short to midterm postoperative prognosis as of the other MV lesions can be achieved through tailored MV repair techniques ( Figure 3C and Supplementary Table 4 ). Our precise anatomic diagnosis and classification of UCMV with echo especially facilitated the development of precise techniques for MV repair ( 23 – 25 ). The main surgical techniques for the UCMV cohort included chorda detachment, papillary muscle splitting or detachment, leaflet plication, and posterior annuloplasty ( 27 ) ( Table 2 ).…”