**6. An expansible aortic ring for a calibrated subvalvular aortic annuloplasty**

To standardize this physiologically based approach to conservative aortic valve surgery, we designed a calibrated expansible aortic ring that reduces dilated diameters in diastole in order to increase cusp coaptation height, while maintaining root systolic expansibility *(*Figure 7*)* (Lansac et al., 2009).

The aortic rings (Extra-Aortic, CORONEO Inc., Montreal, Canada) are composed of two silicone elastomer cores covered by a polyester textile. Black indicator marks on the ring and suture windows in the ring-holder are incorporated to facilitate optimal suture placement between the two cores. Design prerequisites for the ring were: 1) target *in vivo* device expansion between 5% and 15% over the cardiac cycle, 2) minimized radial thickness of the ring while preserving the desired dynamic behaviour, 3) ring durability, 4) stable and predictable bioreaction with surrounding tissues.

Characteristics of this new device were established *in vitro* on the bench-top. Biocompatibility of the ring and the impact of its implantation on root dynamics were studied *in vivo* in the ovine model.

Fig. 7. Expansible aortic ring (left hand side) and its detailed constitution (right hand side)

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 observation (Lansac et al., 2009).

## **7. Remodeling of the aortic root with cusp resuspension and subvalvular external aortic ring annuloplasty for aortic aneurysms**

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 al., 2011a).

#### **7.1 Dissection of the subvalvular plane**

230 Aortic Valve Surgery

(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,

**6. An expansible aortic ring for a calibrated subvalvular aortic annuloplasty**  To standardize this physiologically based approach to conservative aortic valve surgery, we designed a calibrated expansible aortic ring that reduces dilated diameters in diastole in order to increase cusp coaptation height, while maintaining root systolic expansibility

The aortic rings (Extra-Aortic, CORONEO Inc., Montreal, Canada) are composed of two silicone elastomer cores covered by a polyester textile. Black indicator marks on the ring and suture windows in the ring-holder are incorporated to facilitate optimal suture placement between the two cores. Design prerequisites for the ring were: 1) target *in vivo* device expansion between 5% and 15% over the cardiac cycle, 2) minimized radial thickness of the ring while preserving the desired dynamic behaviour, 3) ring durability, 4) stable and

Characteristics of this new device were established *in vitro* on the bench-top. Biocompatibility of the ring and the impact of its implantation on root dynamics were

Fabric sheath

Fig. 7. Expansible aortic ring (left hand side) and its detailed constitution (right hand side)

Elastomer core

Positioning indicators

Thread Suturing

area

2009, 2010a, 2010b, 2010c, 2011a, 2011b).

predictable bioreaction with surrounding tissues.

*(*Figure 7*)* (Lansac et al., 2009).

studied *in vivo* in the ovine model.

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 protecting cusp repair (Table 1).


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

An Expansible Aortic Ring for a Standardized and Physiological Approach of Aortic Valve Repair 233

A) B) C)

Fig. 9. First step of cusp repair. Alignment of cusp free edges to determine excess of length

Fig. 10. Step by step suturing of the tube graft for Remodeling (A), from beginning (B) to the

**7.5 Second step for cusp repair: Resuspension of cusp effective height (fig. 11)**  Once suturing of the tube graft performed,, commissural traction sutures are placed to mimic a pressurized aortic root in order to measure the effective height of each cusp. A dedicated cusp caliper is used to evaluate any residual or induced cusp prolapse (Fehling

(A-B) and plicating of stitches to equalize each hemi-cusp (C-D)

A B C

D

end (C)

#### **7.2 Placement of 5 subvalvular anchoring stitches (fig. 8)**

Five threads of 2.0 coated polyester fiber pledgeted (3/8 needle 25, Ethibond, Ethicon Inc., Somerville NJ, USA), are placed from the inside out as "U" stitches (width of 3 mm) circumferentially in the subvalvular plane, clock-wise beginning from the non-coronary sinus. Three stitches are placed 2 mm below the nadir of insertion of each cusp, and two stitches are placed below two of the three commissures at the base of the interleaflet triangles (no suture is placed at the base of the interleaflet triangle situated between the right and noncoronary sinuses to avoid potential injury to the bundle of His and membranous septum\*)

Fig. 8. Positioning of the stitches. RC: right coronary, LC: left coronary, NC: non-coronary, \*: membranous septum

#### **7.3 First step of valve repair: Alignment of adjacent cusp free edges (fig. 9)**

A polypropylene 6/0 stay suture is passed through each noduli of Arantius. A grasper pulls outwards on the corresponding commissure while the two stitches at the level of the noduli of Arantia are retracted in the opposite direction. The excess length of free edge is then determined. Same step is performed for each hemi-cusp. Distance between the two stitches determines the area for the central plicating stitches to equalize each hemi-cusp (polypropylene 5 or 6/0-13).

#### **7.4 Remodeling of the aortic root (fig. 10)**

The Remodeling technique is performed using a Gelweave ValsalvaTM graft. Remodeling of the aortic root is standardized by scalloping the Valsalva graft into three symmetrical neosinuses using the linear demarcations on the bulging part of the graft. The heights of the scallops to suture the commissures are cut up to the transition point between circumferential and axial folds in the graft. Suturing of the graft starts on the left coronary sinus at the nadir of the sinus (1) towards half sinus (2). Another running suture is begun at the tip of the commissure (3) towards corresponding hemi-sinus (4). (polypropylene 5.0). Right and non coronary sinuses are then sutured.

Five threads of 2.0 coated polyester fiber pledgeted (3/8 needle 25, Ethibond, Ethicon Inc., Somerville NJ, USA), are placed from the inside out as "U" stitches (width of 3 mm) circumferentially in the subvalvular plane, clock-wise beginning from the non-coronary sinus. Three stitches are placed 2 mm below the nadir of insertion of each cusp, and two stitches are placed below two of the three commissures at the base of the interleaflet triangles (no suture is placed at the base of the interleaflet triangle situated between the right and noncoronary sinuses to avoid potential injury to the bundle of His and

Fig. 8. Positioning of the stitches. RC: right coronary, LC: left coronary, NC: non-coronary,

A polypropylene 6/0 stay suture is passed through each noduli of Arantius. A grasper pulls outwards on the corresponding commissure while the two stitches at the level of the noduli of Arantia are retracted in the opposite direction. The excess length of free edge is then determined. Same step is performed for each hemi-cusp. Distance between the two stitches determines the area for the central plicating stitches to equalize each hemi-cusp

The Remodeling technique is performed using a Gelweave ValsalvaTM graft. Remodeling of the aortic root is standardized by scalloping the Valsalva graft into three symmetrical neosinuses using the linear demarcations on the bulging part of the graft. The heights of the scallops to suture the commissures are cut up to the transition point between circumferential and axial folds in the graft. Suturing of the graft starts on the left coronary sinus at the nadir of the sinus (1) towards half sinus (2). Another running suture is begun at the tip of the commissure (3) towards corresponding hemi-sinus (4). (polypropylene 5.0). Right and non

**7.3 First step of valve repair: Alignment of adjacent cusp free edges (fig. 9)** 

**7.2 Placement of 5 subvalvular anchoring stitches (fig. 8)** 

membranous septum\*)

\*: membranous septum

(polypropylene 5 or 6/0-13).

coronary sinuses are then sutured.

**7.4 Remodeling of the aortic root (fig. 10)** 

Fig. 9. First step of cusp repair. Alignment of cusp free edges to determine excess of length (A-B) and plicating of stitches to equalize each hemi-cusp (C-D)

Fig. 10. Step by step suturing of the tube graft for Remodeling (A), from beginning (B) to the end (C)

#### **7.5 Second step for cusp repair: Resuspension of cusp effective height (fig. 11)**

Once suturing of the tube graft performed,, commissural traction sutures are placed to mimic a pressurized aortic root in order to measure the effective height of each cusp. A dedicated cusp caliper is used to evaluate any residual or induced cusp prolapse (Fehling

An Expansible Aortic Ring for a Standardized and Physiological Approach of Aortic Valve Repair 235

A B C

Fig. 13. Final steps of the procedure: the holder is removed (A) and final aspect of the

Reimplantation of the coronary ostia buttons into the corresponding 'neo-sinuses' of Valsalva is obtained using 5.0 Prolene (fig. 13). The thicker part of the Gelweave graft can be cut to suture the coronaries ostia if they are ascensionned which is often the case for the right coronary button. Distal anastomosis is performed using a 4–5/0 Prolene running

neoaortic root after anastomosis of the coronary ostia (B-C)

Fig. 14. Bicuspid valves: Placement of the 5 subvalvular "U" stitches

suture in a standard fashion.

Instruments, Karlstein, Germany) (Schäfers et al., 2006). Plicating stitches are added on the free edge of the culprit leaflet until an effective height of 8 to 10 mm is obtained.

Fig. 11. Commissural traction and cusps measurement using a calliper (A-B) and cusps height correction (C)

#### **7.6 Placement of the prosthetic aortic ring in the subvalvular position (fig. 12)**

The five anchoring "U" stitches are passed through the inner aspect of the prosthetic expansible aortic ring (Extra aortic, CORONEO Inc., Montreal, QC, Canada). The attachment point between the handle and the ring-holder is aligned with the commissure between the non- and right coronary sinuses (atrioventricular node) where there is no anchoring stitch. The ring is then descended around the remodelled aortic root (a). The holder is released and knots are tied to secure the ring in subvalvular position (b).

Fig. 12. Suture and descent of the prosthetic aortic ring

Instruments, Karlstein, Germany) (Schäfers et al., 2006). Plicating stitches are added on the

free edge of the culprit leaflet until an effective height of 8 to 10 mm is obtained.

A B C

Fig. 11. Commissural traction and cusps measurement using a calliper (A-B) and cusps

**7.6 Placement of the prosthetic aortic ring in the subvalvular position (fig. 12)** 

knots are tied to secure the ring in subvalvular position (b).

Fig. 12. Suture and descent of the prosthetic aortic ring

The five anchoring "U" stitches are passed through the inner aspect of the prosthetic expansible aortic ring (Extra aortic, CORONEO Inc., Montreal, QC, Canada). The attachment point between the handle and the ring-holder is aligned with the commissure between the non- and right coronary sinuses (atrioventricular node) where there is no anchoring stitch. The ring is then descended around the remodelled aortic root (a). The holder is released and

height correction (C)

Fig. 13. Final steps of the procedure: the holder is removed (A) and final aspect of the neoaortic root after anastomosis of the coronary ostia (B-C)

Reimplantation of the coronary ostia buttons into the corresponding 'neo-sinuses' of Valsalva is obtained using 5.0 Prolene (fig. 13). The thicker part of the Gelweave graft can be cut to suture the coronaries ostia if they are ascensionned which is often the case for the right coronary button. Distal anastomosis is performed using a 4–5/0 Prolene running suture in a standard fashion.

Fig. 14. Bicuspid valves: Placement of the 5 subvalvular "U" stitches

An Expansible Aortic Ring for a Standardized and Physiological Approach of Aortic Valve Repair 237

is dissected free from the pulmonary artery and infundibulum and from the roof of the left atrium, in order to reach the subvalvular plane. The internal aortic annular base diameter is measured with Hegar dilators. It is the sole criterion to determine the size of the expansible

Five "U" stitches (2.0 coated polyester fiber, 3/8 needle 25) are circumferentially placed from inside out in the subvalvular plane, below the nadirs of each cusp and at the base of each interleaflet triangles except the one situated between the right and noncoronary sinuses

**8.3 Valve repair: Alignment of adjacent cusp free edges followed by resuspension of** 

Commissural traction stitches are placed. Alignment of adjacent cusp free edges is performed. Excess cusp length is corrected by plicating central stitches if <5mm and limited cusp resection if >5 mm. Effective height cusp resuspension is then re-evaluated on the unfused cusp using a cusp caliper (Fehling Instruments, Karlstein, Germany). Plicating central stitches are added on the free edge of this cusp until an effective height of 10 mm is obtained. Re-alignment of the two cusps free edges is then performed by adding plicating

external subvalvular aortic ring, which is downsized by one size (CORONEO, Inc.).

**8.2 Placement of the five anchoring subvalvular "U" stitches** 

**the cusp effective height** 

stitches on the fused cusp (fig. 16).

with running suture (fig. 17).

to avoid potential injury to the bundle of His and membranous septum.

Fig. 16. Aortic valve resuspension for repair of isolated aortic insufficiency

**8.4 Placement of the aortic prosthetic ring in subvalvular position and TEE control**  The subvalvular stitches are passed through the inner aspect of the 'open' subvalvular prosthetic ring, in order that it may be positioned below the coronary arteries. The ring is closed with a series of "U" stitches. Transsection of the aorta is closed in standard fashion

### **7.7 Specific aspect of repair for aortic root aneurysms with bicuspid aortic valves**

Dissection of the subvalvular plane as well as sizing of the ring and graft are similar to tricuspid valves (Lansac et al., 2011b). Principle for repair, applicable to all types of bicuspid valves, consists of aligning the free edges of the two cusps, and placing the commissures in the neo-aortic root at 180° according to Schafers et al. Therefore, the Remodeling technique is performed by tailoring the Gelweave ValsalvaTM graft into two symmetrical sinuses of Valsalva (Schäfers et al., 2010) (fig. 14-15).

Fig. 15. Bicuspid valves: Valve repair and suture of the remodeling
