**4. Surgical management**

## **4.1 Peri-operative evaluation**

Trans-oesophageal echo (TOE) affords an excellent tool for the diagnosis of the mechanism of aortic regurgitation and is essential intra-operatively to assess the quality of the repair. The two dimensional axial and longitudinal views of the aortic root allow measurement of the aortic annulus, STJ, ascending aorta, as well aortic cusp free margin diameters. The plane of coaptation and leaflet prolapse or folding can be easily demonstrated. Colour doppler allows quantification of the severity of regurgitation and its direction. Eccentricity of the jet can give vital clues of leaflet prolapse or restriction.

Contrast-enhanced computed tomography of the chest is used to assess aneurysm morphology and coronary angiography should be routinely performed to determine the need for concomitant bypass grafting.

#### **4.2 Intra-operative technique**

92 Aortic Valve Surgery

While the Carpentier classification for mitral valve regurgitation has seen widespread application, in recent years, a similar functional classification system for aortic regurgitation has been developed by El Khoury and colleagues [8]. In this system, the aortic valve is viewed as two components, the annulus and valve leaflets, the former consisting of the

The system classifies aortic regurgitation as secondary to I) dilatation of the aortic root structures, II) excessive leaflet motion (ie. prolapse) or III) restriction in leaflet motion such as that in bicuspid, rheumatic and other degenerative processes. One or more of these

Untreated symptomatic aortic regurgitation carries a poor prognosis. In patients with New York Heart Association Class III or IV symptoms, 4-year survival is around 30% [9] Symptomatic patients should be offered prompt surgical intervention for aortic regurgitation. Asymptomatic patients should be considered for surgery when left ventricular dimensions

In patients with aneurysms of the aortic root, valve-sparing aortic root surgery should be considered when root diameter exceeds 50mm. In those with Marfan's syndrome or a history of aortic dissection, surgery should be considered at 45mm regardless of the prospect

*Conditions when 45mm is a trigger for replacement* 

2. Bicuspid valve needing an operation alone 3. Strong family history of rupture/dissection 4. Rapid progression of aneursym (>5mm/year)

Surgery for replacement of the ascending aorta should be considered when the diameter

Surgery may be offered earlier in the presence of a rapidly enlarging aneurysm or coexisting moderate to severe aortic regurgitation. In the case of the latter, earlier surgery before the aneurysm has reached a substantial size may increase the chances of valve preservation by limiting further stretching of valve cusps beyond repair. Aneurysms of the

Trans-oesophageal echo (TOE) affords an excellent tool for the diagnosis of the mechanism of aortic regurgitation and is essential intra-operatively to assess the quality of the repair. The two dimensional axial and longitudinal views of the aortic root allow measurement of the aortic annulus, STJ, ascending aorta, as well aortic cusp free margin diameters. The plane of coaptation and leaflet prolapse or folding can be easily demonstrated. Colour

increase above the normal range or when ventricular function begins to decline.

1. Marfan's, Loeys-Dietz, etc

aortic root are the most common indication for surgery.

Table 2. Conditions where aortic dilatation of 45mm is a trigger for replacement

**3.1 Classification of aortic regurgitation** 

ventriculo-aortic junction and the sinotubular junction.

**3.2 Clinical consequences of aortic regurgitation** 

of valve preservation.

reaches 50mm.

**4. Surgical management 4.1 Peri-operative evaluation** 

lesions may be present in to a given case of aortic regurgitation [8].

Access to the heart is obtained via median sternotomy. Cardiopulmonary bypass with ascending aorta, femoral or axillary artery cannulation may be required depending on the specifics of concomitant ascending arch pathology.

### **4.3 Valve sparing aortic root replacement**

Valve-sparing aortic root reconstruction involves preservation of the native aortic valve while replacing the ascending aorta. This procedure was initially described by Dr Tirone David [10] and Sir Magdi Yacoub [11]. The two main techniques in widespread practice are aortic valve re-implantation and aortic root remodelling.

Repair of the aortic valve leaflets may be essential for short and long term success of the operation, if there is significant leaflet prolapse or restriction.

#### **4.3.1 Aortic root remodelling**

The first technique for correction of aortic root dilatation was described by Sir Magdi Yacoub [11] and subsequently also by Dr Tirone David (David Remodelling procedure). This procedure corrects STJ dilatation and creates neo-aortic sinuses, but does not affect the annular size.

In this technique, the ascending aorta is transected and the aortic root is excised to within 2–3mm of the valve attachment. Subsequently, a Dacron graft sized to the ideal STJ diameter is incised to create 3 evenly spaced tongues. This mimics the aortic sinuses, thus creating a neo-aortic root (Fig. 6 and 7). The apices of the valve commissures are then anastomosed to the corresponding points on the trimmed graft with pledgeted mattress sutures. The proximal sewing line is completed with a running polypropylene suture.

In a modification of the David Remodelling procedure, a separate Teflon "annuloplasty" is added in an attempt to prevent future annular dilatation. This annular plication is not done circumferentially, but over the length of the fibrous LVOT, which is the component most often affected by dilatation.

### **4.3.2 Aortic valve re-implantation**

The re-implantation technique is performed by excising the aortic sinuses and placing a row of braided non-absorbable horizontal mattress sutures evenly around the left ventricular outflow tract below the level of the annulus (Fig. 8). These are passed through the proximal end of the graft which is tied in position as an external annuloplasty. The commissures are firstly secured within the graft ensuring that they are taught and vertically upright (Fig. 9 and 10), then the remnant of the aortic sinus tissue is then re-implanted inside the prosthesis with running polypropylene suture.

In the David re-implantation procedure, a single Dacron graft is used to achieve both annular and STJ plication. The advantages are greater simplicity and haemostasis. The disadvantages are incorporation of the muscular LVOT in the plication process, which if excessive may result in a higher than normal sub-annular gradient.

Valve-Sparing Aortic Root Replacement and Aortic Valve Repair 95

Fig. 8. Placement of horizontal mattress sutures around the left ventricular outflow tract

Fig. 9. Re-implantation of the native aortic valve within the vascular graft

during root re-implantation

Fig. 6. Insertion of the fashioned graft during the root remodelling procedure

*Reprinted from Heart, Lung and Circulation, 2004;13 Suppl 3, Matalanis G, Valve sparing aortic root repairs--an anatomical approach. S13-18., Copyright (2004), with permission from Elsevier* 

Fig. 7. Final appearance of the aortic root after aortic root remodelling

Fig. 6. Insertion of the fashioned graft during the root remodelling procedure

*Reprinted from Heart, Lung and Circulation, 2004;13 Suppl 3, Matalanis G, Valve sparing aortic root repairs--an* 

*anatomical approach. S13-18., Copyright (2004), with permission from Elsevier*  Fig. 7. Final appearance of the aortic root after aortic root remodelling

Fig. 8. Placement of horizontal mattress sutures around the left ventricular outflow tract during root re-implantation

Fig. 9. Re-implantation of the native aortic valve within the vascular graft

Valve-Sparing Aortic Root Replacement and Aortic Valve Repair 97

In cases where the sinuses of Valsalva and aortic annulus are not dilated, mere reduction of the sinotubular junction to an appropriate diameter will often cure valve incompetence. In such instances the ascending aorta is transected just above the commissures, which are pulled upward and towards each other until satisfactory coaptation of the aortic cusps are

In situations where the aortic cusps are asymmetric, the commissures may need to be spaced in a non-equidistant fashion such that the free margins coapt adequately. The vascular graft is subsequently anastomosed directly to the proximal ascending aorta at the sinotubular

Much has been said about formulae for choosing the correct diameter of graft. In our institution we prefer placing the three commisural sutures and then elevating them upwards and inward until adequate coaptation of the aortic valve is achieved. A standard prosthetic valve sizer is then used to obtain the diameter of this corrected annulus/STJ and a

Care must be made when choosing a conduit size for a re-implantation procedure. After the prosthesis is placed over the annulus, an additional 3-5mm needs to be added to the diameter prior to selection. In our experience, most females have a diameter of 26 to 30mm

It is important to note that in late presenting patients with very large aortic roots and severe aortic regurgitation, the leaflets are often overstretched with elongated free margins. Thus, after isolated correction of root dimensions the leaflets will tend to prolapse, even if they did

Leaflets are assessed for prolapse as determined by a discrepancy in leaflet free margin height relative to its neighbours, and the cusp coaptation height. The latter is considered as indicative of prolapse if the height of coaptation above the level of the annulus is less than

Prolapse can be readily corrected by shortening the free margin back to normal. Minor degrees can be corrected with simple fine plication sutures either at the mid-point of the free

In patients with more extensive degrees of prolapse, or in those with stress fenestrations, a neo-free margin may be constructed with a running polytetrafluoroethylene suture, also

Patients with connective tissue pathology such as Marfan's syndrome present a unique challenge. Marfan's Syndrome has previously been reported as a predictor of recurrent aortic regurgitation after root replacement. In these patients, the valves are structurally abnormal due to altered fibrillin metabolism, resulting in greater fragility compared to normal cusps [17, 18]. As such, these patients may benefit from additional leaflet reinforcement with running polytetrafluoroethylene sutures in addition to plication, so as to pre-empt further

The optimal technique for correction of leaflet prolapse is yet to be established. Previous studies have found recurrence of aortic regurgitation after placing plicating sutures at the commissures, and hence have preferred placing them at the mid point of the free margin

not previously. This is not a contra indication to repair, and can be readily corrected.

margin or at its commissural ends until satisfactory coaptation is achieved (Fig. 11a).

known as leaflet "re-suspension", in addition to plication (Fig. 11b).

**4.4 Sinotubular junction restoration** 

junction with a running 4-0 suture.

respective conduit is then chosen.

**4.6 Repair of aortic valve prolapse** 

half of that of the top of the commissures.

leaflet free margin stretch or tears.

and males 28 to 32mm. [16]

**4.5 Sizing the graft** 

achieved. This is the diameter chosen for the graft.

*Reprinted from Heart, Lung and Circulation, 2004;13 Suppl 3, Matalanis G, Valve sparing aortic root repairs--an anatomical approach. S13-18., Copyright (2004), with permission from Elsevier* 

Fig. 10. Final appearance of the reconstructed aortic root following the re-implantation procedure

## **4.3.3 Recreating the sinuses of Valsalva**

When the re-implantation technique was first described by David and Feindel, one perceived disadvantage was the potential physiological disturbance caused by the attachment of a tubular graft to the aortic annulus, thus eliminating the aortic sinuses. Given the role of the sinuses in preventing leafelt stress and strain, there was a concern that their absence would result in abnormal motion of the cusps and contribute toward structural deterioration and late recurrent regurgitation [3].

Subsequently, various modifications were proposed for the creation pseudosinuses to minimise physiological disturbance. The most commonly used technique involves oversizing a tubular graft (diameter which is twice the average height of the cusps) and placing plicating sutures at the level of the annulus and STJ. This acts to "pinch down" the graft, resulting in an outward bulge where the native sinuses would be located [12, 13]. This is sometimes referred to as the "David V" or "Stanford" modification [14].

To minimse the need for technical modifications to the re-implantation procedure, Ruggero De Paulis introduced the Valsava Graft, a Dacron conduit which incorporates the sinuses of Valsalva in the "skirt" portion of the graft [15]. This prosthesis recreates the nomal shape of the aortic sinuses to enable normal valve motion, decrease stress, and potentially increase durability without the need for the manual fashioning of neosinuses.

#### **4.4 Sinotubular junction restoration**

In cases where the sinuses of Valsalva and aortic annulus are not dilated, mere reduction of the sinotubular junction to an appropriate diameter will often cure valve incompetence. In such instances the ascending aorta is transected just above the commissures, which are pulled upward and towards each other until satisfactory coaptation of the aortic cusps are achieved. This is the diameter chosen for the graft.

In situations where the aortic cusps are asymmetric, the commissures may need to be spaced in a non-equidistant fashion such that the free margins coapt adequately. The vascular graft is subsequently anastomosed directly to the proximal ascending aorta at the sinotubular junction with a running 4-0 suture.

#### **4.5 Sizing the graft**

96 Aortic Valve Surgery

*Reprinted from Heart, Lung and Circulation, 2004;13 Suppl 3, Matalanis G, Valve sparing aortic root repairs--an* 

When the re-implantation technique was first described by David and Feindel, one perceived disadvantage was the potential physiological disturbance caused by the attachment of a tubular graft to the aortic annulus, thus eliminating the aortic sinuses. Given the role of the sinuses in preventing leafelt stress and strain, there was a concern that their absence would result in abnormal motion of the cusps and contribute toward structural deterioration and

Subsequently, various modifications were proposed for the creation pseudosinuses to minimise physiological disturbance. The most commonly used technique involves oversizing a tubular graft (diameter which is twice the average height of the cusps) and placing plicating sutures at the level of the annulus and STJ. This acts to "pinch down" the graft, resulting in an outward bulge where the native sinuses would be located [12, 13]. This is sometimes

To minimse the need for technical modifications to the re-implantation procedure, Ruggero De Paulis introduced the Valsava Graft, a Dacron conduit which incorporates the sinuses of Valsalva in the "skirt" portion of the graft [15]. This prosthesis recreates the nomal shape of the aortic sinuses to enable normal valve motion, decrease stress, and potentially increase

Fig. 10. Final appearance of the reconstructed aortic root following the re-implantation

*anatomical approach. S13-18., Copyright (2004), with permission from Elsevier* 

referred to as the "David V" or "Stanford" modification [14].

durability without the need for the manual fashioning of neosinuses.

**4.3.3 Recreating the sinuses of Valsalva** 

late recurrent regurgitation [3].

procedure

Much has been said about formulae for choosing the correct diameter of graft. In our institution we prefer placing the three commisural sutures and then elevating them upwards and inward until adequate coaptation of the aortic valve is achieved. A standard prosthetic valve sizer is then used to obtain the diameter of this corrected annulus/STJ and a respective conduit is then chosen.

Care must be made when choosing a conduit size for a re-implantation procedure. After the prosthesis is placed over the annulus, an additional 3-5mm needs to be added to the diameter prior to selection. In our experience, most females have a diameter of 26 to 30mm and males 28 to 32mm. [16]

#### **4.6 Repair of aortic valve prolapse**

It is important to note that in late presenting patients with very large aortic roots and severe aortic regurgitation, the leaflets are often overstretched with elongated free margins. Thus, after isolated correction of root dimensions the leaflets will tend to prolapse, even if they did not previously. This is not a contra indication to repair, and can be readily corrected.

Leaflets are assessed for prolapse as determined by a discrepancy in leaflet free margin height relative to its neighbours, and the cusp coaptation height. The latter is considered as indicative of prolapse if the height of coaptation above the level of the annulus is less than half of that of the top of the commissures.

Prolapse can be readily corrected by shortening the free margin back to normal. Minor degrees can be corrected with simple fine plication sutures either at the mid-point of the free margin or at its commissural ends until satisfactory coaptation is achieved (Fig. 11a).

In patients with more extensive degrees of prolapse, or in those with stress fenestrations, a neo-free margin may be constructed with a running polytetrafluoroethylene suture, also known as leaflet "re-suspension", in addition to plication (Fig. 11b).

Patients with connective tissue pathology such as Marfan's syndrome present a unique challenge. Marfan's Syndrome has previously been reported as a predictor of recurrent aortic regurgitation after root replacement. In these patients, the valves are structurally abnormal due to altered fibrillin metabolism, resulting in greater fragility compared to normal cusps [17, 18]. As such, these patients may benefit from additional leaflet reinforcement with running polytetrafluoroethylene sutures in addition to plication, so as to pre-empt further leaflet free margin stretch or tears.

The optimal technique for correction of leaflet prolapse is yet to be established. Previous studies have found recurrence of aortic regurgitation after placing plicating sutures at the commissures, and hence have preferred placing them at the mid point of the free margin

Valve-Sparing Aortic Root Replacement and Aortic Valve Repair 99

Once pulsatile flow is reastablished, intra-operative trans-oesophageal echocardiography is

In our institution we do not accept regurgitation >1+ or eccentric jets. The level at which the FM coapts needs to be more than half way between the annulus and STJ, and the amount of

Dr Tirone David and colleagues from the Toronto Group recently published their results on 289 patients undergoing valve-sparing aortic root replacement using both the re-implantation (n=228) and remodelling (n=61) techniques [12]. Nine percent of patients underwent surgery for acute type A dissection. Overall, freedom from recurrent regurgitation was high at 86.8% ± 3.8% at 12 years follow-up. Patients undergoing the re-implantation technique experienced greater freedom from recurrent regurgitation compared to those undergoing remodeling (91.0% ± 3.8% versus 82.6% ± 6.2%, p = 0.035), however technique was not an independent predictor of late recurrent regurgitation. In this publication, the Toronto Group also showed that patient survival after undergoing valve-reimplantation was comparable to that of the

The largest published series on the re-implantation technique is from Kallenbach and colleagues from Hannover, Germany, who in 2005, published their results of 284 consecutive patients undergoing the re-implantation procedure [20]. The series showed that the reimplantation procedure leads to excellent mid-term and late outcomes with freedom from re-operation due to recurrent aortic regurgitation was 91.1±2.5% at 5 years and 87.1±4.5% at

In recent years, most surgeons have favoured the re-implantation technique, given the reinforcement of the aortic annulus which prevents subsequent dilatation, which is particularly important in patients with connective tissue diseases such as Marfan syndrome. Indeed, the evidence suggests that the re-implantation technique is less likely to result in

Valve-sparing aortic root replacement was principally conceived for patients with morphologically normal valve leaflets where aortic regurgitation was caused solely by a dilated root. They were initially applied to patients with early grades of aortic regurgitation and less severe aortic root dilatation where the leaflets have only been minimally stretched. However, combining leaflet prolapse correction with aortic valve sparing techniques permits extension of the benefits of valve sparing procedures to patients with advanced aortic regurgitation or aneurysms. In the past decade, there has been growing interest in such an

In David and colleagues' earlier experience, published in 2001 [22], only 11% of patients underwent repair of cusp prolapse. However, almost a decade later, the group's latest report shows that 40% of patients had at least one leaflet free margin plicated while 22% underwent reinforcement of the free margin with a running polytetreafluoroethylene suture [12]. In a seminal publication, the Brussels Group, recently presented their results on 264 patients undergoing elective aortic valve repair for regurgitation occuring in isolation (43%) and in combination with aortic dilatation (57%) [8]. Leaflet repair techniques included free margin plication, resuspension as well as trangular resection with pericardial patch repair, while

**5. Outcomes of valve-sparing aortic root replacement and valve repair** 

essential to assess the quality of the operation.

coaptation needs to be greater than or equal to 5mm.

general population when matched for age and gender.

recurrent regurgitation in the long-term [12, 21].

approach.

10 years. Late survival at 10 years was also high at 80.4±5.7% at 10 years.

**5.1 Valve-sparing root replacement with concomitant valve repair** 

[19]. However, at our centre, we have favored the former technique with encouraging results. It is an attractive approach as the peri-commissural areas are often the most stretched component in prolonged root dilatation and plication here provides support at the most vulnerable site.

*Reprinted from Heart, Lung and Circulation, 2004;13 Suppl 3, Matalanis G, Valve sparing aortic root repairs--an anatomical approach. S13-18., Copyright (2004), with permission from Elsevier* 

Fig. 11. Methods of leaflet prolapse correction with (a) plication and (b) leaflet resuspension

#### **4.7 Isolated aortic valve repair**

Isolated prolapse of trileaflet aortic valve cusps without co-existent aortic root dilatation is uncommon. However, when encountered, valve repair can be accomplished using the techniques described. Cusp perforation, such as that secondary to endocarditis, can be easily corrected by using autologous pericardium.

#### **4.8 Bicuspid aortic valves**

A bicuspid valve's anterior cusp is most commonly prolapsed. Here, repair may be accomplished by placing plicating sutures at the free margin, or by placing a running polytetrafluoroethylene suture as with trileaflet valves. This approach works well for anatomically "pure" bicuspid valves (Type 0).

In functionally bicuspid valves (Type 1), attention must be paid to the raphe. If the raphe has adequate mobility and morphology, it may be shaved and preserved. However if it is severely restricted in movement or heavily calcified, a triangular resection of the raphe may be performed, the leaflet edges primarily reapproximated with running polypropylene sutures. If adequate tissue is not present, autologous or bovine pericardium may be used. Coaptation may be further enhanced with additional free margin plication and resuspension.

Where there is co-existent aortic root dilatation subcommissural triangle plication may be needed to enhance coaptation.

#### **4.9 Completion assessment / Post repair Transeophageal Echo (TOE)**

Following completion of the root repair saline testing is performed and leaflets are assessed for competance, symmetry, prolapse or any restriction.

[19]. However, at our centre, we have favored the former technique with encouraging results. It is an attractive approach as the peri-commissural areas are often the most stretched component in prolonged root dilatation and plication here provides support at the

*Reprinted from Heart, Lung and Circulation, 2004;13 Suppl 3, Matalanis G, Valve sparing aortic root repairs--an* 

Fig. 11. Methods of leaflet prolapse correction with (a) plication and (b) leaflet resuspension

Isolated prolapse of trileaflet aortic valve cusps without co-existent aortic root dilatation is uncommon. However, when encountered, valve repair can be accomplished using the techniques described. Cusp perforation, such as that secondary to endocarditis, can be easily

A bicuspid valve's anterior cusp is most commonly prolapsed. Here, repair may be accomplished by placing plicating sutures at the free margin, or by placing a running polytetrafluoroethylene suture as with trileaflet valves. This approach works well for

In functionally bicuspid valves (Type 1), attention must be paid to the raphe. If the raphe has adequate mobility and morphology, it may be shaved and preserved. However if it is severely restricted in movement or heavily calcified, a triangular resection of the raphe may be performed, the leaflet edges primarily reapproximated with running polypropylene sutures. If adequate tissue is not present, autologous or bovine pericardium may be used. Coaptation may be further enhanced with additional free margin plication and resuspension. Where there is co-existent aortic root dilatation subcommissural triangle plication may be

Following completion of the root repair saline testing is performed and leaflets are assessed

**4.9 Completion assessment / Post repair Transeophageal Echo (TOE)** 

for competance, symmetry, prolapse or any restriction.

(a) (b)

*anatomical approach. S13-18., Copyright (2004), with permission from Elsevier* 

most vulnerable site.

**4.7 Isolated aortic valve repair** 

**4.8 Bicuspid aortic valves** 

needed to enhance coaptation.

corrected by using autologous pericardium.

anatomically "pure" bicuspid valves (Type 0).

Once pulsatile flow is reastablished, intra-operative trans-oesophageal echocardiography is essential to assess the quality of the operation.

In our institution we do not accept regurgitation >1+ or eccentric jets. The level at which the FM coapts needs to be more than half way between the annulus and STJ, and the amount of coaptation needs to be greater than or equal to 5mm.
