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Page 2 of 23 Ancona et al. Mini-invasive Surg 2020;4:79 I http://dx.doi.org/10.20517/2574-1225.2020.80

The present review will cover the intraprocedural guidance of the most utilised approaches for mitral
valve (MV) repair in the setting of MR, such as (1) leaflet repair: edge to edge repair; (2) chordal repair:
adjustable transapical beating-heart chordal implantation; and (3) annular repair: percutaneous direct or
indirect annuloplasty.

Baseline intraprocedural evaluation of MR grading
MR severity varies in a spectrum, especially in functional MR which is load dependent. Hence, it is
[1]
imperative to obtain a baseline grading prior to all transcatheter procedures , in order to extrapolate the
procedural results under similar hemodynamic conditions and controlled heart rate. In addition, as the
ultrasound machine settings (particularly color scale and gain) could influence evaluation, these should
be standardized for pre- and post-device evaluation. A multi-modal approach seems the most suitable and
[2]
appropriate to quantify MR in this setting .

LEAFLET REPAIR: PERCUTANEOUS EDGE-EDGE
[3]
The most widely experienced percutaneous approach to MV repair mimics surgical edge to edge repair .
TM
Nowadays two devices are currently available: Mitraclip system (Abbott Vascular Inc., Menlo, CA, USA)
and PASCAL device (Edwards Life- sciences, Irvine, California).
TM
The crucial procedural steps are the following: (1) safe trans-septal puncture at an optimal site and
placement of the guide catheter; (2) steering of the device delivery system (DS) within the LA toward
MV plane; (3) perpendicular alignment of DS to the MV coaptation line; (4) creation of the tissue bridge
between anterior and posterior leaflet at the target site via grasping and adequate leaflet insertion; (5)
evaluation of MR reduction without significant mitral stenosis; and (6) assessment of residual interatrial
[4-6]
septal shunt .
TM
Mitraclip system
The Mitraclip system consists of a polyester fabric covered cobalt-chromium implant with two arms
TM
which can be opened and closed with a steerable-guiding mechanism. Currently there are 2 available
devices: NTR and XTR.

Intraprocedural monitoring
Under general anesthesia, a trans-septal approach is utilized and the DS is aligned perpendicularly to the
MV plane and to the coaptation line of MV leaflets. The device is deployed after successfully grasping of
leaflets, at the level of the regurgitant target lesion. In degenerative MR, the clip aims to anchor the flail
and/or prolapsing segments, whereas, in cases of functional MR, to improve coaptation of the leaflets. If
needed, additional clip(s) may be placed.

Echocardiographic (2D/3D TEE) and fluoroscopic imaging are used during the procedure. Procedural steps
and relative imaging modalities are summarized in Table 1 .
[7]

Transseptal puncture
The initial and fundamental step is the trans-septal puncture (TSP) [Figure 1]. The determination of
the optimal TSP site is of utmost importance for MitraClip procedure, as a suboptimal puncture site
TM
often leads to additional steering maneuvers to correct the position of the DS within the left atrium (LA),
increasing complexity and duration of the procedure. Moreover, optimal puncture height also depends
on MV pathology, particularly in cases of degenerative and secondary MR. In patients with prolapse/flail,
the puncture site should be higher (~4.5-5 cm above the mitral annulus), thus providing enough space to
adequately maneuver the DS within the LA. In cases of secondary MR with prominent apical tethering
of the leaflets, since the coaptation point is usually shifted below the annular plane, a lower puncture site