The preferred location for the transseptal puncture in a MitraClip procedure is posterior and at the level of the medial commissure of the mitral valve. Some punctures, however, may occur too anteriorly. As a result, considerable difficulty with leaflet grasping arises because the trajectory of the steerable sleeve is anterior-to-posterior (A, arrow; G, arrow), and thus not perpendicular to the mitral annular plane (“aorta hugger”). (B) Without perpendicularity, simultaneous grasping of both leaflets is challenging, particularly when there is a large gap height, markedly asymmetrical leaflet lengths, or mitral annular calcification present. When an aorta hugger occurs, inadequate grasping of the anterior leaflet can be difficult (B, arrow).
Common causes for this scenario are slippage of the transseptal needle during advancement (typically superior from the intended puncture site) or travel through a patent foramen ovale. The transseptal puncture may be repeated to gain a relatively posterior position, or the following advanced steering maneuver can be utilized: (C) Model of the mitral valve (MV) and interatrial septum (IAS) that illustrates the trajectory of the aorta hugger, which travels posterior to anterior in the apical direction. (D) To counter the effect of the aorta hugger, “+” is added to the steerable guide catheter (arrow), leading to posterior movement of the steerable sleeve (arrowheads). (E) Next, “A” is added to the sleeve leading to antero-lateral trajectory (arrowheads). (F) “M” is then applied to center the sleeve in the middle of the MV. (H) Repeat three-dimensional echocardiography showing improvement in the trajectory following the previous maneuvers (arrowheads).
Ao, Ascending aorta; Ant, anterior; IAS, interatrial septum; LA, left atrium; LV, left ventricle; M, medial; MV, mitral valve; Post, posterior.