**3.2 Surgical indications**

224 Aortic Valve Surgery

Fig. 3. Changes at each level of the aortic root time related to left ventricular and ascending aorta pressures in one sheep, a) during three cardiac cycles and b) detail of one cardiac cycle. c) Dynamic changes of tilt angle of the aortic root time related to left ventricular and aortic pressures. d) cross-sectional area diagram of the aortic root at maximum expansion during ejection (sonomicrometry) showing the clover-shaped orifice of the aortic valve. *Ao* aortic pressure, *LV* left ventricular pressure, *SoV* sinuses of Valsalva, *B* annular base,

Therefore, the durability of native aortic valve seems to rely on a dynamic triad associating 1) systolic expansion of the aortic root, 2) a clover-shaped aortic orifice that embraces the bulging sinuses of Valsalva, and 3) tilting dynamics of the aortic valve (Lansac et al., 2002). Aortic valve surgery should try to preserve these baseline dynamics as much as possible

Dystrophic aortic roots are characterized by dilation of both functional diameters of the aortic root: the aortic annular base and sino-tubular junction (STJ) diameters (>25mm and >35 mm respectively), preventing coaptation of otherwise thin and pliable valves (De Waroux et al., 2007; La Canna et al., 2009; Lansac et al., 2008, 2010c). Cusp prolapse is often associated with root aneurysms and is the most common cause of isolated dystrophic aortic insufficiency (AI). On an echocardiographic study of patients with aortic root aneurysms (n=700) or isolated aortic insufficiency (n=595), average aortic annular base diameter was

*STJ* sinotubular, *C* commissures, *AA* ascending aorta, *L* leaflet

using more physiologically based surgical approaches.

**3.1 Dystrophic aortic roots: A diameter disease** 

**3. Dystrophic aortic roots** 

Surgical emergency operation is indicated in the setting of acute ascending aortic dissection or rupture into the pericardium (acute cardiac tamponade). Operative mortality remains significant and death is almost certain in the case of rupture or acute dissection if not surgically addressed.

Based on natural history of ascending aortic aneurysms, prophylactic surgery seems appropriate at 5 to 5.5 cm diameter depending on the etiology. Intervention criteria are summarized in Figure 4 (Hiratzka et al., 2010; Vahanian et al., 2007). Actually, elective surgery of the ascending aorta is much safer than emergency intervention (mortality 4.3%).

For patients with Marfan's syndrome and bicuspid valves size criterion is somewhat lower. In those patients, prophylactic repair is warranted for an intervention criterion of 4.5 to 5.0 cm diameter for most authors (Bentall & De Bono, 1968; Yacoub et al., 1998). Dissection or rupture have been stated at sizes less than 5.0 cm in several cases, and an increase rate of aneurysm dilatation greater than 5mm/y is known to lead to an 4.1-fold risk of complications.

Fig. 4. Surgical indications for ascending aorta aneurysms and/or aortic insufficiency

An Expansible Aortic Ring for a Standardized and Physiological Approach of Aortic Valve Repair 227

order to restore proper valve function (David & Feindel, 1992; Yacoub et al., 1983). The reimplantation technique offers aortic annulus support but withdraws the sinuses of Valsalva and includes the interleaflet triangles within a graft tube, thus impairing root dynamics (David et al., 1992, 2006, 2007). In contrast, the remodeling technique provides more physiologic movements of the cusps within three reconstructed neo-sinuses, thus preserving root expansibility through the interleaflet triangles, but without addressing

These techniques spare the patient from anticoagulation and prosthetic valve morbidity with a 10-year survival rate ranging from 80.4 to 92% (mean 88.2%) (Aicher et al., 2010; Lansac & Di Centa, 2010c). In both techniques with proper patient selection, the results up to 10 years are equally excellent. However, in earlier series of the remodeling technique, the reoperation rate was higher after type A aortic dissection and in patients with Marfan syndrome (Lansac et al., 2006; Leyh et al., 2002; Luciani et al., 1999; Yacoub et al., 1998). In the unselected population of the original remodeling series, up to 30 % of patients presented recurrence of AI grade II or III (Erasmi et al., 2005; Furukawa et al., 1999; Lansac et al., 2006; Luciani et al., 1999). The only risk factor for failure was a dilated native aortic annulus (diameter ≥ 25 mm) (Hanke et al., 2009; Lansac et al., 2006; Leyh et al., 2002; Luciani et al.,

All studies show that the remodeling technique exhibits valve dynamics closest to those of the native aortic root. The recreation of the sinuses of Valsalva preserves vortex formation, as well as cusp opening and closing dynamics, thus, reducing cusp stress which theoretically improves their durability. The valve shows asymmetric motion after reimplantation. The cusp bending deformation index is increased with the reimplantation techniques and sinus prosthesis compared with the control and remodeling groups (Erasmi

Leyh and colleagues clearly demonstrated that distensibility of the aortic root and a proper valve motion were better preserved after the remodeling than after the reimplantation technique (Leyh et al., 1999). They showed that reimplantation with a straight tube abolished root distensibility at all levels; the cusps took longer for closing, and systolic contact of at least one cusp against the tube graft was constantly found. Reconstruction of the sinuses may assure a sufficient gap to avoid any such contact between the open cusp and the Dacron wall, which is known to be responsible for cusp thickening and accelerated degeneration (Aybek et al., 2005; De Paulis et al., 2002). The presence of vortices inside the neosinuses of Valsalva preserves the slow closing displacement of the cusps and is associated with a valve motion similar to that of normal subjects (De Paulis et al., 2002; Maselli et al., 2005). Although not significant, valve velocities after the remodeling procedure using the Valsalva graft (Gelweave Valsalva™, Vascutek, Inc.) are closer to

Therefore, all dynamic studies suggest that cusp motion and flow patterns across the reconstructed aortic root are more physiologic (1) after remodeling of the aortic root than after reimplantation of the aortic valve and (2) after procedures using a prosthetic conduit

**4.2 Aortic root and valve dynamics after remodeling or reimplantation** 

normal than after reimplantation using the same graft (De Paulis et al., 2002).

fashioned with neosinuses of Valsalva than without.

et al., 2005; Furukawa et al., 1999; Grande-Allen et al., 2000).

annular base dilation (Yacoub et al., 1983, 1998).

1999; Yacoub et al., 1998).

**4.2.1 In vitro studies** 

**4.2.2 In vivo studies** 

Other risk factors for aortic dissection in patients with Marfan syndrome include familial history of aortic dissection and a ratio between observed diameter and predicted diameter above 1.3. Women with Turner's syndrome showing an ascending aortic diameter >25mm/m2 should be operated on (David et al., 2006).

#### **3.3 Preoperative imaging**

Transthoracic and transesophageal echocardiography are performed to define the anatomy of the valve and the phenotype of the ascending aorta (Roman et al., 1987). It remains critical in order to analyze the lesional mechanism of aortic insufficiency both pre- and postrepair in case of aortic valve repair procedures. It measures the 4 characteristics aortic diameters at end diastole, in the parasternal long-axis view, at 4 levels: aortic annular base, sinuses of Valsalva, sino-tubular junction and supra-coronary aorta. Measurements are made perpendicular to the long axis of the aorta using the leading edge technique in views showing the largest aortic diameters. (Fig. 2) (Roman et al., 1987). Analysis of the valve evaluates the number of cusps and direction of regurgitant jet. An eccentric jet towards the anterior mitral leaflet identifies a right coronary cusp prolapse whereas a jet directed towards the septum corresponds to a non or left coronary cusp prolapse (De Waroux et al., 2007).

Most patients are initially evaluated and followed with helical CT (computed tomography) scans, completed with a 3-dimensional reconstruction of the data to increase the accuracy of aneurysm measurements, determination of its proximal and distal extent, and differentiation between dissection, penetrating ulcera or intramural hematoma. Moreover, it allows preoperative coronary arteries assessment.

As a routine, it is recommended to perform both an echocardiography and a helical computed tomography in order to evaluate and confirm the size of the aneurysm.

#### **3.4 Surgical techniques for dystrophic aortic roots**

Treatment for dystrophic aortic root aneurysms can be either replacement of the aortic valve and root, or repair of the aortic valve, while replacing the dilated aortic root in case of aneurysms.

#### **3.4.1 Aortic valve and root replacement procedure**

Depending on root phenotype, it consists either of isolated valve replacement (isolated aortic insufficiency), composite valve and graft replacement (Bentall procedure, for aortic root aneurysms (Bentall & De Bono, 1968)) or supracoronary graft and/or valve replacement (supra-coronary aneurysm).

#### **3.4.2 Aortic valve-sparing procedures**

Owing to the improved understanding of aortic valve dynamics, reconstructive methods have been developed to treat aortic insufficiency, based on sparing or repairing the native aortic valve, while replacing or stabilizing the other components of the aortic root, in order to avoid complications of prosthetic valves.

#### **4. Remodeling of the aortic root and reimplantation of the aortic valve**

#### **4.1 Description of the original valve sparing procedures**

The two original valve sparing procedure - remodeling of the aortic root and reimplantation of the aortic valve - focused on root reconstruction to reduce the dilated root diameters in order to restore proper valve function (David & Feindel, 1992; Yacoub et al., 1983). The reimplantation technique offers aortic annulus support but withdraws the sinuses of Valsalva and includes the interleaflet triangles within a graft tube, thus impairing root dynamics (David et al., 1992, 2006, 2007). In contrast, the remodeling technique provides more physiologic movements of the cusps within three reconstructed neo-sinuses, thus preserving root expansibility through the interleaflet triangles, but without addressing annular base dilation (Yacoub et al., 1983, 1998).

These techniques spare the patient from anticoagulation and prosthetic valve morbidity with a 10-year survival rate ranging from 80.4 to 92% (mean 88.2%) (Aicher et al., 2010; Lansac & Di Centa, 2010c). In both techniques with proper patient selection, the results up to 10 years are equally excellent. However, in earlier series of the remodeling technique, the reoperation rate was higher after type A aortic dissection and in patients with Marfan syndrome (Lansac et al., 2006; Leyh et al., 2002; Luciani et al., 1999; Yacoub et al., 1998). In the unselected population of the original remodeling series, up to 30 % of patients presented recurrence of AI grade II or III (Erasmi et al., 2005; Furukawa et al., 1999; Lansac et al., 2006; Luciani et al., 1999). The only risk factor for failure was a dilated native aortic annulus (diameter ≥ 25 mm) (Hanke et al., 2009; Lansac et al., 2006; Leyh et al., 2002; Luciani et al., 1999; Yacoub et al., 1998).

#### **4.2 Aortic root and valve dynamics after remodeling or reimplantation 4.2.1 In vitro studies**

All studies show that the remodeling technique exhibits valve dynamics closest to those of the native aortic root. The recreation of the sinuses of Valsalva preserves vortex formation, as well as cusp opening and closing dynamics, thus, reducing cusp stress which theoretically improves their durability. The valve shows asymmetric motion after reimplantation. The cusp bending deformation index is increased with the reimplantation techniques and sinus prosthesis compared with the control and remodeling groups (Erasmi et al., 2005; Furukawa et al., 1999; Grande-Allen et al., 2000).

#### **4.2.2 In vivo studies**

226 Aortic Valve Surgery

Other risk factors for aortic dissection in patients with Marfan syndrome include familial history of aortic dissection and a ratio between observed diameter and predicted diameter above 1.3. Women with Turner's syndrome showing an ascending aortic diameter

Transthoracic and transesophageal echocardiography are performed to define the anatomy of the valve and the phenotype of the ascending aorta (Roman et al., 1987). It remains critical in order to analyze the lesional mechanism of aortic insufficiency both pre- and postrepair in case of aortic valve repair procedures. It measures the 4 characteristics aortic diameters at end diastole, in the parasternal long-axis view, at 4 levels: aortic annular base, sinuses of Valsalva, sino-tubular junction and supra-coronary aorta. Measurements are made perpendicular to the long axis of the aorta using the leading edge technique in views showing the largest aortic diameters. (Fig. 2) (Roman et al., 1987). Analysis of the valve evaluates the number of cusps and direction of regurgitant jet. An eccentric jet towards the anterior mitral leaflet identifies a right coronary cusp prolapse whereas a jet directed towards the septum

Most patients are initially evaluated and followed with helical CT (computed tomography) scans, completed with a 3-dimensional reconstruction of the data to increase the accuracy of aneurysm measurements, determination of its proximal and distal extent, and differentiation between dissection, penetrating ulcera or intramural hematoma. Moreover,

As a routine, it is recommended to perform both an echocardiography and a helical

Treatment for dystrophic aortic root aneurysms can be either replacement of the aortic valve and root, or repair of the aortic valve, while replacing the dilated aortic root in case of

Depending on root phenotype, it consists either of isolated valve replacement (isolated aortic insufficiency), composite valve and graft replacement (Bentall procedure, for aortic root aneurysms (Bentall & De Bono, 1968)) or supracoronary graft and/or valve replacement

Owing to the improved understanding of aortic valve dynamics, reconstructive methods have been developed to treat aortic insufficiency, based on sparing or repairing the native aortic valve, while replacing or stabilizing the other components of the aortic root, in order

The two original valve sparing procedure - remodeling of the aortic root and reimplantation of the aortic valve - focused on root reconstruction to reduce the dilated root diameters in

**4. Remodeling of the aortic root and reimplantation of the aortic valve** 

computed tomography in order to evaluate and confirm the size of the aneurysm.

corresponds to a non or left coronary cusp prolapse (De Waroux et al., 2007).

>25mm/m2 should be operated on (David et al., 2006).

it allows preoperative coronary arteries assessment.

**3.4 Surgical techniques for dystrophic aortic roots** 

**3.4.1 Aortic valve and root replacement procedure** 

**3.3 Preoperative imaging** 

aneurysms.

(supra-coronary aneurysm).

**3.4.2 Aortic valve-sparing procedures** 

to avoid complications of prosthetic valves.

**4.1 Description of the original valve sparing procedures** 

Leyh and colleagues clearly demonstrated that distensibility of the aortic root and a proper valve motion were better preserved after the remodeling than after the reimplantation technique (Leyh et al., 1999). They showed that reimplantation with a straight tube abolished root distensibility at all levels; the cusps took longer for closing, and systolic contact of at least one cusp against the tube graft was constantly found. Reconstruction of the sinuses may assure a sufficient gap to avoid any such contact between the open cusp and the Dacron wall, which is known to be responsible for cusp thickening and accelerated degeneration (Aybek et al., 2005; De Paulis et al., 2002). The presence of vortices inside the neosinuses of Valsalva preserves the slow closing displacement of the cusps and is associated with a valve motion similar to that of normal subjects (De Paulis et al., 2002; Maselli et al., 2005). Although not significant, valve velocities after the remodeling procedure using the Valsalva graft (Gelweave Valsalva™, Vascutek, Inc.) are closer to normal than after reimplantation using the same graft (De Paulis et al., 2002).

Therefore, all dynamic studies suggest that cusp motion and flow patterns across the reconstructed aortic root are more physiologic (1) after remodeling of the aortic root than after reimplantation of the aortic valve and (2) after procedures using a prosthetic conduit fashioned with neosinuses of Valsalva than without.

An Expansible Aortic Ring for a Standardized and Physiological Approach of Aortic Valve Repair 229

resuspension with an effective height ≥8 to 10 mm in order to restore cusp coaptation (Bierbach et al., 2010; Schäfers et al., 2006). In their report, an effective height ≥9 mm is an excellent predictor for a good haemodynamic outcome after valve repair. This technique allows correction of any residual or induced symmetrical prolapse after reduction of the STJ provided by the remodeling procedure. Indeed, Soncini et al., using finite element analysis showed that noduli of Arantius were lowered towards the valve orifice during valve closure after reimplantation (3.8 mm) and remodeling (3.3 mm) (Soncini et al., 2009). Subvalvular annuloplasty through an aortic ring or proximal suture of a reimplantation tube graft partially compensates the induced symmetric prolapse by increasing the coaptation height. However, in the absence of cusp resuspension, coaptation level may remain too low (at the level of the aortic annular plane or below). This can induce a billowing aspect of the cusps with progressive drop of the coaptation level and height (<4mm) which have been described as a risk factor for reoperation (De Waroux et al., 2007). Normalisation of effective height leads to a high probability of normal or near-normal aortic valve function (Bierbach et al.,

As restorations of both root geometry and cusp coaptation are the prerequisite for a successful valve sparing procedure, we designed a standardized surgical management of dystrophic aortic roots towards a more systematic and physiological repair approach (Fig. 6). This approach is proposed based on the principles of reduction of dilated root diameters

Fig. 6. Standardized and physiological approach to aortic valve repair according each

2010; Schäfers et al., 2006).

phenotype of the ascending aorta

#### **4.3 Modification of original remodeling and reimplantation techniques**

Numerous technical variations aimed to associate preservation of aortic root dynamics with vortices (neosinuses of Valsalva) and expansibility (interleaflet triangles) with the treatment of dilated native annulus (± cusp lesion) (Hopkins, 2003; Lansac & Di Centa, 2010c).

David et al. added an external Teflon strip on the aortomitral junction to the remodeling technique (David III) or oversized (+4 mm) the tube graft for the reimplantation technique (David IV) (David, 1999, 2005). The David V technique used an even larger graft size (+ 6-8 mm), which is "necked down" at both the bottom and the top ends to create graft pseudosinuses (Miller, 2007). Many authors suggested different methods to customize the tube graft for the reimplantation or remodeling in order to provide better neosinuses of Valsalva. More recently De Paulis et al. designed the Valsalva graft (Gelweave ValsalvaTM, Vascutek, Inc.) with vertical pleats in the proximal section for reconstruction of the aortic root and with the standard horizontal pleats for ascending aorta replacement (Cochran & Kunzelman, 2000; Gleason, 2005; Hess et al., 2005; Hetzer et al., 2008; Kollar, 2007; Miller, 2007; Morishita et al., 2002; Ruvolo & Fattouch, 2009; Scensson, 2003; Takamoto et al., 2006; Urbanski et al., 2009; Zehr et al., 2000).

We suggest combining advantages of both original valve sparing techniques by associating the Remodeling reconstruction of the aortic root with an expansible sub-valvular annuloplasty (Figure 5).

Fig. 5. Combination of Remodeling and Reimplantation procedures by placing an external subvalvular ring annuloplasty associated to the Remodeling procedure

#### **5. From original valve sparing procedures to a physiological approach of aortic valve repair**

Although restoration of root geometry is an important prerequisite for a successful valve sparing, preventing recurrence of aortic insufficiency remains a challenge. Most failures with valve sparing techniques are due to residual cusp prolapse, either as a primary unrecognized lesion or secondary to an induced prolapse after root reconstruction. Despite its more frequent detection intra operatively, cusp prolapse remains challenging to evaluate and treat. Schafers et al proposed to use a cusp caliper to obtain symmetrical cusp

Numerous technical variations aimed to associate preservation of aortic root dynamics with vortices (neosinuses of Valsalva) and expansibility (interleaflet triangles) with the treatment

David et al. added an external Teflon strip on the aortomitral junction to the remodeling technique (David III) or oversized (+4 mm) the tube graft for the reimplantation technique (David IV) (David, 1999, 2005). The David V technique used an even larger graft size (+ 6-8 mm), which is "necked down" at both the bottom and the top ends to create graft pseudosinuses (Miller, 2007). Many authors suggested different methods to customize the tube graft for the reimplantation or remodeling in order to provide better neosinuses of Valsalva. More recently De Paulis et al. designed the Valsalva graft (Gelweave ValsalvaTM, Vascutek, Inc.) with vertical pleats in the proximal section for reconstruction of the aortic root and with the standard horizontal pleats for ascending aorta replacement (Cochran & Kunzelman, 2000; Gleason, 2005; Hess et al., 2005; Hetzer et al., 2008; Kollar, 2007; Miller, 2007; Morishita et al., 2002; Ruvolo & Fattouch, 2009; Scensson, 2003; Takamoto et al., 2006;

We suggest combining advantages of both original valve sparing techniques by associating the Remodeling reconstruction of the aortic root with an expansible sub-valvular

> **Remodeling Reimplantation Remodeling +**

 **Subvalvular external aortic annuloplasty**

Fig. 5. Combination of Remodeling and Reimplantation procedures by placing an external

**5. From original valve sparing procedures to a physiological approach of** 

Although restoration of root geometry is an important prerequisite for a successful valve sparing, preventing recurrence of aortic insufficiency remains a challenge. Most failures with valve sparing techniques are due to residual cusp prolapse, either as a primary unrecognized lesion or secondary to an induced prolapse after root reconstruction. Despite its more frequent detection intra operatively, cusp prolapse remains challenging to evaluate and treat. Schafers et al proposed to use a cusp caliper to obtain symmetrical cusp

subvalvular ring annuloplasty associated to the Remodeling procedure

of dilated native annulus (± cusp lesion) (Hopkins, 2003; Lansac & Di Centa, 2010c).

**4.3 Modification of original remodeling and reimplantation techniques** 

Urbanski et al., 2009; Zehr et al., 2000).

annuloplasty (Figure 5).

**aortic valve repair** 

resuspension with an effective height ≥8 to 10 mm in order to restore cusp coaptation (Bierbach et al., 2010; Schäfers et al., 2006). In their report, an effective height ≥9 mm is an excellent predictor for a good haemodynamic outcome after valve repair. This technique allows correction of any residual or induced symmetrical prolapse after reduction of the STJ provided by the remodeling procedure. Indeed, Soncini et al., using finite element analysis showed that noduli of Arantius were lowered towards the valve orifice during valve closure after reimplantation (3.8 mm) and remodeling (3.3 mm) (Soncini et al., 2009). Subvalvular annuloplasty through an aortic ring or proximal suture of a reimplantation tube graft partially compensates the induced symmetric prolapse by increasing the coaptation height. However, in the absence of cusp resuspension, coaptation level may remain too low (at the level of the aortic annular plane or below). This can induce a billowing aspect of the cusps with progressive drop of the coaptation level and height (<4mm) which have been described as a risk factor for reoperation (De Waroux et al., 2007). Normalisation of effective height leads to a high probability of normal or near-normal aortic valve function (Bierbach et al., 2010; Schäfers et al., 2006).

As restorations of both root geometry and cusp coaptation are the prerequisite for a successful valve sparing procedure, we designed a standardized surgical management of dystrophic aortic roots towards a more systematic and physiological repair approach (Fig. 6). This approach is proposed based on the principles of reduction of dilated root diameters

Fig. 6. Standardized and physiological approach to aortic valve repair according each phenotype of the ascending aorta

An Expansible Aortic Ring for a Standardized and Physiological Approach of Aortic Valve Repair 231

Root dynamics were assessed using intracardiac echography before surgery, and at 6 months. Histological, scanning electron microscopy and mechanical studies were then performed on explanted samples. Prosthetic rings created a significant reduction of the aortic annular base diameter without significant transvalvular gradient (mean 3.4 ± 2.1 mmHg). Coaptation height was increased from 2.5 ± 0.7 mm to 6.2 ± 1.1 mm (p<0.001). Dynamics of the root were well preserved. The device was clearly visible in explanted sheep hearts at 6 months. There was no erosion of the external ring into the aorta or adjacent structures, neither at the level of the aortic annular base nor at the STJ level. Coronary arteries were patent in all cases. Mechanical testing on 6 month explanted samples revealed no significant differences in elastic modulus. Histomorphological studies showed incorporation of the material without degradation. Aortic cusps remained thin and pliable. Macroscopic examination of the hearts did not show calcification as confirmed by Alizarin red staining. Polyester fabric was fully integrated in the tissue and colonized by a dense extracellular matrix. Low and high magnifications of the samples showed the encapsulation of the elastomer core in a fibrous zone. No inflammatory reaction was noted around the device and no apparent degradation of the elastomer core was observed by SEM

**7. Remodeling of the aortic root with cusp resuspension and subvalvular** 

We describe a standardized procedure for aortic aneurysms with tricuspid valves (Lansac et al., 2011b). In all cases, intra-operative transesophageal echocardiography (TEE) remains critical in order to analyze the lesional mechanism of AI both pre- and post-repair (Lansac et

After aortic cross-clamping, the aneurysm is opened and the aortic root and valve are carefully inspected (particularly the geometry of the aortic valve and leaflet morphology). Pliable non retracted cusps are suitable for valve repair. The presence of an intact fenestration, a bicuspid valve or limited calcification is not a contraindication. External dissection of the aortic root is performed down to the base of the aortic annulus which is liberated from the pulmonary artery and infundibulum and from the roof of the left atrium, in order to reach the subvalvular plane. The wall of the aortic sinus is totally removed leaving a fringe of aortic wall of approximately 2 mm. The internal aortic annular base diameter is measured with Hegar dilators. Measurement of the native aortic annular base diameter with Hegar dilators is the sole criterion to determine size of the expansible aortic ring which is undersized from one size in order to increase coaptation height while

**Tube graft Ø (mm)** 28 30 32 34

Table 1. Criteria for choice of the aortic ring and tube graft diameters

**ring Ø (mm)** 25 27 29 31

Aortic annular base Ø (Hegar dilators, mm) **25-27 28-30 31-33 ≥34** 

**external aortic ring annuloplasty for aortic aneurysms** 

observation (Lansac et al., 2009).

**7.1 Dissection of the subvalvular plane** 

protecting cusp repair (Table 1).

**Subvalvular aortic** 

al., 2011a).

(aortic annular base and STJ); respect of root dynamics (expansibility through the interleaflet triangles and restoration of sinuses of Valsalva) and retoration of cusp coaptation height (measurement of the effective height). Depending on the phenotype of the ascending aorta, reduction of the sinotubular junction diameter will be achieved through a physiological reconstruction of the root according to the Remodeling technique (root aneurysm, sinuses of Valsalva≥45 mm), a supracoronary graft (supracoronary aneurysm, sinuses of Valsalva<40 mm). Valve repair is achieved in two steps: 1) before root reconstruction by aligning adjacent cusp free edges, excess of length is corrected using plicating central stitches or limited resection; 2) after root reconstruction, resuspending residual or induced cusp prolapse in order to obtain an effective height of 8 mm (distance between the free edge of the cusp to the aortic annular base). Expansible subvalvular annuloplasty is systematically added using an external expansible aortic ring in order to increase cusp coaptation height, while maintaining systolic expansibility. Ring is "open" in case of isolated aortic insufficiency or supra-coronary aneurysm, in order that it may be positioned below the coronary arteries without detaching them from the aortic root (Lansac et al., 2005a, 2006, 2009, 2010a, 2010b, 2010c, 2011a, 2011b).
