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Page 6 of 12 Belluschi et al. Mini-invasive Surg 2020;4:58 I http://dx.doi.org/10.20517/2574-1225.2020.48

Systolic anterior motion
It has been postulated that the edge-to-edge technique may play a role in the prevention of post-repair
SAM of the anterior mitral valve leaflet, which can dynamically create LVOT obstruction in the presence
of anatomical risk factors. Few series reported such results of the edge-to-edge in this setting, and even less
in the context of hypertrophic obstructive cardiomyopathy (HOCM). Mascagni and coworkers adopted the
[12]
[30]
double-orifice technique to treat successfully four patients with post-repair SAM , while Brinster et al.
showed optimal results in 20 cases even at 4 years of follow-up without the need for reintervention. In
our center, we adopted the edge-to-edge technique to treat 26 HOCM patients in which septal thickness
was considered inadequate to allow for a safe and effective myectomy with good outcomes: the 8-year
[31]
cumulative incidence function (CIF) of reoperation with death as a competing risk was 7.7% ± 5.2% .
Rescue edge-to-edge
The double-orifice technique, due to the intrinsic versatility and rapidity of its surgical gesture, which is not
time-consuming, has proved to be a valid option even as a rescue procedure, which means to improve the
initial suboptimal result of a conventional repair, when the attempt to save the valve becomes a “surgeon’s
[32]
nightmare”. Gatti et al. described this strategy in 11 patients who underwent other repair techniques and
2
a concomitant final rescue edge-to-edge for residual MR, thus reducing the jet area from 3.0 ± 0.8 cm to
2
0.7 ± 0.9 cm (P = 0.00014), and adding only 14.9 ± 2.8 min to the aortic cross-clamp times. Our experience
[33]
has been very gratifying under those circumstances . However, in these challenging scenarios, the efficacy
of the edge-to-edge technique may be very difficult to predict, and not surprisingly other authors have
[34]
reported suboptimal results . Finally, particular attention should be given when applying an additional
edge-to-edge to a triangular/quadrangular resection: the relative reduction of tissue due to previous
resection can be responsible for small final orifices, eventually resulting in mitral stenosis, particularly in
cases of wide and deep Alfieri’s stitches.

MINIMALLY INVASIVE APPROACH
The edge-to-edge technique can be easily performed through a minimally invasive approach with relatively
short the cross-clamp times, which are generally longer in case of small access and limited surgical view as
compared to median sternotomy. An antero-lateral right mini-thoracotomy (6 cm) is usually performed
through the third or fourth intercostal space and a soft tissue retractor is inserted. After surgical TOE-
guided femoral venous and arterial cannulation, cardiopulmonary bypass is instituted at 28-30 °C. In those
patients who require concomitant procedures, such as atrial septal defect closure or tricuspid valve repair,
an additional percutaneous cannula may be inserted in the jugular vein. Endoaortic balloon (Heartport,
Inc, Redwood City, CA, USA) inserted in the femoral artery under echocardiographic guidance or
transthoracic surgical clamps (i.e., the Chitwood clamp, Scanlan International, Inc, Minneapolis, MN, USA;
or the Cygnet flexible clamp, Vitalitec, Plymouth, MA, USA) are adopted for aortic cross-clamp. Antegrade
intermittent cold blood cardioplegia or crystalloid cardioplegic solutions are administered directly into
the aortic root. Access to the mitral valve is generally achieved through a left atriotomy and a left atrial
retractor is placed through a parasternal incision. The valve analysis and repair is performed both under
direct and video-assisted vision using a 30° camera.

A robotic approach has been reported as well, since the versatility and simplicity of the double-orifice
[35]
technique enhances its application .
A recent publication showed excellent long-term results (up to 19 years) with minimally invasive edge-to-
[36]
edge repair in myxomatous degenerative mitral valve regurgitation . Indeed, analyzing 97 consecutive
patients with severe myxomatous mitral regurgitation who underwent mitral valve repair through a right
minithoracotomy between 1999 and 2006, it was reported a 16-year overall survival of 95.9% ± 2.02%
(95%CI: 89.39-98.43). At 16 years, the CIF of cardiac death, with non-cardiac death as a competing risk,