**6. Adjuncts to septal myectomy**

### **6.1 SAM correction**

*Cardiac Surgery Procedures*

septum is trimmed off all around (**Figure 2**). The TAESM is the most commonly used technique and it has been associated with very low mortality, consistent

The MV is approached through the left atrium, in the interatrial groove. Then, the base of the AL is widely detached from commissure to commissure, with the septum that lies just in front of the surgeon. The myectomy is continued further toward the apex with at least 1 cm depth of muscle removed. The anterior MV leaflet is then reconstructed (sometimes using an autologous pericardial patch with the size of the patch that should be as biggest as possible, in order to move posteriorly toward the left ventricle the coaptation plane). This approach is useful for those patients with diffuse hypertrophy extending to or below the papillary muscles with midcavity muscular obstruction: these patients are suboptimal candidates for the Morrow procedure. Benefits of the transmitral exposure include a wide view of the ventricular septum, absent risk of injury to the aortic valve cusps, and the opportunity to address concomitant abnormalities of the MV and

alleviation of outflow gradients and excellent long-term survival [10].

**5.3 Complete septal myectomy by a double approach (aortic and mitral)**

In patients with simultaneous MR due to SAM, the insufficiency is almost always reduced or eliminated by myectomy alone. Sometimes, there may be associated a lesion of the aortic valve and/or fibrous subaortic stenosis; these also require surgical correction, depending on their severity. Intraoperative echocardiography helps the surgeon to determine the individual extent of the disease and decide on the

**5.2 Transmitral septal myectomy (TMSM)**

*Extension of the resection under the membranous septum.*

**110**

subvalvular apparatus.

**Figure 2.**

necessary scope of resection.

SAM describes the dynamic movement of the MV during systole anteriorly toward the LVOT. It occurs in 31–61% of HCM patients, and it is associated with resting LVOT obstruction in 25–50% of them [14].

SAM-mediated MR typically resolves with extended myectomy alone, anyway, a well comprehension of all the mechanisms that can predispose to or precipitate SAM, is important, in order to treat this mechanism. Factors predisposing to SAM are:

a. structural anomalies such as:


b.geometric factors such as:


c.kinetic factors such as

• hyperdynamic left ventricle (LV)

Surgical techniques proposed to correct concomitant SAM in HOCM are:

	- triangular resection of PML and ventricularization [16];
	- sliding posterior leaflet plasty technique (moves the coaptation point posteriorly) [17] (**Figures 3**–**5**);
	- modified sliding leaflet technique (middle scallop of PML is resected, differs from Carpentier in eliminating triangular resection) [18] (**Figure 6**);

#### **Figure 3.**

*Quadrangular P2 resection. Adapted from the book "Reconstructive Valve Surgery", by Carpentier et al. 2010, Imprint: Saunders, Copyright: © Saunders 2010.*

#### **Figure 4.**

*Quadrangular P2 resection + sliding plasty. Adapted from the book "Reconstructive Valve Surgery", by Carpentier et al. 2010, Imprint: Saunders, Copyright: © Saunders 2010.*

**113**

**Figure 5.**

**Figure 6.**

*Surgical Treatment of Hypertrophic Obstructive Cardiomyopathy*

*DOI: http://dx.doi.org/10.5772/intechopen.86816*

○ PML folding plasty [19];

*Posterior mitral valve leaflet shortening.*

[20] (**Figure 7**);

the AML) [21];

midline) [22].

○ Loop technique (height adjustment of the mitral leaflets using artificial chordae: after artificial chordae and annuloplasty ring placement in the normal way, a polyester reduction suture with a spaghetti loop supporting it is placed on the posterior leaflet surface, and tied down until its height is <1.5 cm),

*Final result of quadrangular P2 resection + sliding plasty. Adapted from the book "Reconstructive Valve* 

*Surgery", by Carpentier et al. 2010, Imprint: Saunders, Copyright: © Saunders 2010.*

○ chordal translocation (PML secondary chordae are transected and moved to

• *Changes to anterior leaflet height*, in order to reduce the redundant leaflet and,

○ edge-to-edge, or Alfieri stitch technique (A1-P1 stitch instead of

subsequently, the A-P length ratio (risk factor for SAM development):

*Surgical Treatment of Hypertrophic Obstructive Cardiomyopathy DOI: http://dx.doi.org/10.5772/intechopen.86816*

#### **Figure 5.**

*Cardiac Surgery Procedures*

c.kinetic factors such as

height of 1 cm:

• hyperdynamic left ventricle (LV)

riorly) [17] (**Figures 3**–**5**);

*Imprint: Saunders, Copyright: © Saunders 2010.*

Surgical techniques proposed to correct concomitant SAM in HOCM are:

○ triangular resection of PML and ventricularization [16];

• *Changes to posterior leaflet height*, in order to avoid anterior shifting of the coaptation point closer to the base of the anterior leaflet, which predispose to SAM [15]. The resulting posterior mitral leaflet (PML) should have a reduced

○ sliding posterior leaflet plasty technique (moves the coaptation point poste-

○ modified sliding leaflet technique (middle scallop of PML is resected, differs from Carpentier in eliminating triangular resection) [18] (**Figure 6**);

*Quadrangular P2 resection. Adapted from the book "Reconstructive Valve Surgery", by Carpentier et al. 2010,* 

**112**

**Figure 4.**

**Figure 3.**

*Quadrangular P2 resection + sliding plasty. Adapted from the book "Reconstructive Valve Surgery", by* 

*Carpentier et al. 2010, Imprint: Saunders, Copyright: © Saunders 2010.*

*Final result of quadrangular P2 resection + sliding plasty. Adapted from the book "Reconstructive Valve Surgery", by Carpentier et al. 2010, Imprint: Saunders, Copyright: © Saunders 2010.*

#### **Figure 6.**

*Posterior mitral valve leaflet shortening.*


	- annular enlargement (post-MV repair, especially in Barlow's disease): 36–40 mm annular rings are used in presence of excessive mitral tissue [26];
	- annular plication: plication sutures are used to tie down the PML to the annulus [27];
