**4. Surgical technique**

### **4.1. Aortic root replacement**

#### *4.1.1. Aortic root replacement with a composite graft*

This operation is frequently referred to as the Bentall procedure, regardless of whether the composite is a mechanical or biological. Construction of the composite graft can be done either before opening the chest, or during the surgery itself, depending on the surgeon's preference. Constructing a biological composite with a graft and a stentless valve (i.e., Valsalva graft and Freestyle valve), might require more time then when using a stented valve and a tubular Dacron graft, and in these cases it is preferable to construct the composite before opening the chest.

CPB is established at 34°C using a single two-stage venous cannula and left atrial vent. The aorta is occluded just proximal to the brachiocephalic artery. Cardioplegia is given. The ascending aorta is opened transversely in its midportion. The patient's aortic root is dissected from the surrounding tissues. Traction stitches are placed above each aortic valve commissure to expose the aortic root. The aortic valve is excised. The coronary arteries are mobilized, retaining a generous button of sinus aorta. A limited dissection of the coronary artery is sufficient to ensure that excision of the coronary artery is complete and that the coronary button will move easily up to the composite prosthesis without kinking or creating undue tension on the artery. The remaining sinus aorta is removed. Diameter of the annulus is calibrated, and an appropriately sized composite prosthesis is chosen. Stitches are placed through the annulus of the aortic valve and brought up through the sewing ring of the prosthesis preferably using single interrupted braided sutures. It is the authors' preference to implant the valve in the vascular graft 2–3 mm above the lower end of the graft, and to place the root stitches through the graft itself and not through the valve ring itself. Doing so, provides the future option of explanting the valve itself if need be for replacement without disrupting the entire root. The composite valve is brought down, and sutures are tied down. Next, a direct anastomosis of the coronary ostia to the graft is made.

The distal end of the graft is then shortened to approximate the distal end of the aorta. The anastomosis is constructed using continuous stitches of 4–0 or 5–0 polypropylene, depending on the thickness and strength of the aorta.

It is the author's preference to use a composite graft constructed from a 27 to 29 mm Freestyle MS valve (Medtronic) sutured into a 28–30 mm Gelweave Valsalva prosthesis (Sulzer Vascutek, Renfrewshire, Scotland) as the choice when implanting a biological tissue valve. This composite requires 30–40 min preparation time, but provides the patient with the potential benefits of: (1) avoiding the need for anticoagulation, (2) excellent hemodynamic performance of stentless valves, (3) incorporation of sinuses of Valsalva into the neoaortic root can improve the function and longevity of stentless valves.

#### *4.1.2. Aortic root replacement with an allograft*

Patients with connective tissue disorders, bicuspid valves, or history of valve infection may be best served with Bentall-type replacement rather than valve-sparing reconstruction. Despite the surgical complexity, long-term experience with VSRR among bicuspid and/or patients

The current literature still lacks a definite answer to that question. Different authors publish very promising short, intermediate and long-term outcomes with both types of surgery. One recent large series published by Girardi et al. describes the outcomes of 890 patients (289 mechanical composites, 421 biological composites, and 180 VSRR). Operative mortality was 0.2% (0% in the VSRR group); the incidence of major postoperative complications was less than 0.5%. Predictors of adverse in-hospital outcome were age, nonelective operation, renal status, reoperation, New York Heart Association class, ejection fraction, and concomitant procedures. Five-year survival was 89.4%. In the propensity-matched groups, the type of operation performed did not affect in-hospital and late outcome. Aortic reintervention rates at 5 years were 0% for the mechanical composite valved graft group, 2.4% for the biologic composite valved graft group, and 7.3% for the valve-sparing reconstruction series. The authors concluded that in the current era, aortic root replacement can be performed with low perioperative risk in high-volume aortic centers. The type of operation performed does not affect early or late survival. Although the mechanical composite valved graft remains the gold standard for durability, the biologic composite valved graft and valve-sparing reconstruction are excellent options for those who cannot take or want to avoid long-term anticoagulation. Another recent paper by David et al. was looking into the outcomes of a young (<70 years) patients group (total of 616 patients); and used propensity matching to compare valve-sparing root replacement to mechanical composite root replacement. The mean age at the work was 46 ± 14 years, mean follow up was 9.8 ± 5.3 years. Their outcomes showed reduced cardiac mortality among the valve-sparing group, the authors concluded that valve-sparing surgery should be the operation of choice for young patients with aortic root aneurysm and normal or

This operation is frequently referred to as the Bentall procedure, regardless of whether the composite is a mechanical or biological. Construction of the composite graft can be done either before opening the chest, or during the surgery itself, depending on the surgeon's preference. Constructing a biological composite with a graft and a stentless valve (i.e., Valsalva graft and Freestyle valve), might require more time then when using a stented valve and a tubular Dacron graft, and in these cases it is preferable to construct the composite before

with connective tissue disorders are associated with excellent outcomes [16].

near-normal aortic cusps [17].

126 Structural Insufficiency Anomalies in Cardiac Valves

**4. Surgical technique**

**4.1. Aortic root replacement**

opening the chest.

*4.1.1. Aortic root replacement with a composite graft*

This is typically performed in the setting of an aortic root infection. An aortic allograft may be used to replace the patient's aortic root completely. The initial steps of the surgery are similar to those mentioned in Section 4.1.2. Typically, the allograft is used intact and in natural anatomic orientation, with only the excess of septal myocardium and the anterior leaflet of the mitral valve removed. Size match is not nearly as important as it is for freehand subcoronary valve replacement, but if the aortic annulus is more than 3 mm larger in diameter than the largest available aortic allograft, the patient's aortic root should be narrowed to approximate the size of the allograft. This can be done conveniently by placing a pledgeted mattress stitch through the aortic annulus alongside the commissures so that when tied, the intercusp triangle below the commissure is obliterated. The allograft is attached to the LVOT at the aortic annulus and below the commissures by simple interrupted stitches of 3–0 or 4–0 polypropylene.

The allograft is slipped over the sutures into the desired position in the LVOT. The sutures are then tied down. Incorporating a felt strip within the suture loops or using pledged sutures has been advocated by some authors, however, it was not found to be necessary in our experience.

The remainder of the operation proceeds as described for aortic root replacement with a composite graft.

#### *4.1.3. Aortic root replacement with an autograft*

The aortic valve may be replaced with the patient's own pulmonary valve (pulmonary autograft) and a pulmonary/aortic allograft used to replace the pulmonary valve. This operation was devised by Ross and carries his name. The detailed surgical technique is described elsewhere. The operation has the advantage of placing autogenous tissue in the high pressure aortic position that theoretically should last indefinitely. The allograft tissue is placed in the low-pressure pulmonary position, where even if it should fail, valve regurgitation is tolerated for a long time.

One main surgical pitfall of this technique entails potential coronary injury, separating the pulmonary trunk from the RVOT above the infundibular septum.

#### **4.2. Valve sparing aortic root replacement**

The exact surgical details of the remodeling and reimplantation procedures are beyond the scope of this chapter, but the main differences are discussed below.

The remodeling operation consists of removing the sinus aorta except for a small rim of aortic tissue around the coronary ostia and a rim of about 5 mm of aortic wall above the aortic valve annulus. Commissures are positioned to achieve good coaptation of the aortic valve cusps. An appropriately trimmed Dacron graft is sutured to the aortic root along the valve circumference (**Figure 1**). It is recommended that when aortic root remodeling procedures, such as the Yacoub operation, are performed in patients with Marfan syndrome, or when the aortic annulus is dilated, an aortic annuloplasty should be performed.

and reinforcing annuloplasty. The final two methods identified are variations on reimplantation. David-IV refers to the technique of using a graft 4 mm larger than the annulus to allow for plication, and David-V employs an even larger graft (6–8 mm larger than the diameter) in order to facilitate the creation of pseudosinuses. Thus, David-I, -IV, and -V are variations on reimplantation, whereas David-II and -III are variations on the remodeling technique originally devised by Yacoub. In the late 1990s through the present day, attention shifted to focus on the finest details in technique, such as cusp reinforcement, graft sizing to allow for billow-

Reimplantation V Adding a graft plication (diameter + 6–8 mm) at both the sinotubular junction and basal

Contemporary Surgical Options for the Aortic Root http://dx.doi.org/10.5772/intechopen.75816 129

**Figure 1.** Schema of valve-sparing aortic root repair. (a) Remodeling and (b) reimplantation [18].

Remodeling III Adding an external synthetic strip over the fibrous portion of the LVOT Reimplantation IV Adding a graft plication (diameter + 4 mm) at the sinotubular junction

ring to create pseudosinuses

**Table 1.** David classification by Millar for valve-sparing aortic root replacement surgery.

Dr. Cameron and the group at Johns Hopkins have published some of the largest series on elective repair of patients with connective tissue disorders in need of aortic root surgery [19]. Although a "classic" Bentall (i.e., composite valve-graft replacement) remains the gold standard in their practice, over the years they have introduced valve-sparing procedures when possible. Their initial valve-sparing approach focused on preservation of sinuses with a remodeling procedure, but it soon became apparent that recurrent aortic insufficiency and annular dilation occurred in a significant number of patients soon after their initial procedure. At their center, as these results began to bear out, they transitioned to the reimplantation technique. This transition coincided with the newly approved De Paulis Valsalva graft and this combination

ing, and plication as a means to recreate sinuses.

**Type # Modification** Reimplantation I Classic Remodeling II Classic

became their exclusive procedure for valve-sparing operations [20].

Reimplantation Procedure, in this procedure, the aortic valve is reimplanted within a polyester tubular graft. The graft is secured to a level plane in the LVOT just below the valve, except in the one sixth of the circumference occupied by the conduction system. This fixes the diameter of the LVOT, but one may reduce the diameter if necessary. The aortic valve is attached (reimplanted) to the inside of the prosthetic graft. The graft determines the diameter of the sinotubular junction.

The reimplantation procedure has undergone a number of modifications by both David and other surgeons. However, the basic concept has been retained (**Figure 1**).

The graft is usually 30–32 mm in diameter, although 28- or 34-mm grafts are occasionally used.

A classification schema beyond simply calling a procedure reimplantation versus remodeling can be seen in **Table 1**. David's classic reimplantation procedure using a cylindrical tube graft is described as David-I, while Yacoub's classic remodeling procedure is described as a David-II. In this system, David-III referred to a remodeling variation where a synthetic strip is placed over the fibrous portion of the left ventricular outflow tract, achieving a narrowing

**Figure 1.** Schema of valve-sparing aortic root repair. (a) Remodeling and (b) reimplantation [18].

The allograft is slipped over the sutures into the desired position in the LVOT. The sutures are then tied down. Incorporating a felt strip within the suture loops or using pledged sutures has been advocated by some authors, however, it was not found to be necessary in our experience. The remainder of the operation proceeds as described for aortic root replacement with a com-

The aortic valve may be replaced with the patient's own pulmonary valve (pulmonary autograft) and a pulmonary/aortic allograft used to replace the pulmonary valve. This operation was devised by Ross and carries his name. The detailed surgical technique is described elsewhere. The operation has the advantage of placing autogenous tissue in the high pressure aortic position that theoretically should last indefinitely. The allograft tissue is placed in the low-pressure pulmonary position, where even if it should fail, valve regurgitation is tolerated for a long time. One main surgical pitfall of this technique entails potential coronary injury, separating the

The exact surgical details of the remodeling and reimplantation procedures are beyond the

The remodeling operation consists of removing the sinus aorta except for a small rim of aortic tissue around the coronary ostia and a rim of about 5 mm of aortic wall above the aortic valve annulus. Commissures are positioned to achieve good coaptation of the aortic valve cusps. An appropriately trimmed Dacron graft is sutured to the aortic root along the valve circumference (**Figure 1**). It is recommended that when aortic root remodeling procedures, such as the Yacoub operation, are performed in patients with Marfan syndrome, or when the aortic

Reimplantation Procedure, in this procedure, the aortic valve is reimplanted within a polyester tubular graft. The graft is secured to a level plane in the LVOT just below the valve, except in the one sixth of the circumference occupied by the conduction system. This fixes the diameter of the LVOT, but one may reduce the diameter if necessary. The aortic valve is attached (reimplanted) to the inside of the prosthetic graft. The graft determines the diameter of the

The reimplantation procedure has undergone a number of modifications by both David and

The graft is usually 30–32 mm in diameter, although 28- or 34-mm grafts are occasionally used. A classification schema beyond simply calling a procedure reimplantation versus remodeling can be seen in **Table 1**. David's classic reimplantation procedure using a cylindrical tube graft is described as David-I, while Yacoub's classic remodeling procedure is described as a David-II. In this system, David-III referred to a remodeling variation where a synthetic strip is placed over the fibrous portion of the left ventricular outflow tract, achieving a narrowing

posite graft.

*4.1.3. Aortic root replacement with an autograft*

128 Structural Insufficiency Anomalies in Cardiac Valves

**4.2. Valve sparing aortic root replacement**

sinotubular junction.

pulmonary trunk from the RVOT above the infundibular septum.

scope of this chapter, but the main differences are discussed below.

annulus is dilated, an aortic annuloplasty should be performed.

other surgeons. However, the basic concept has been retained (**Figure 1**).


**Table 1.** David classification by Millar for valve-sparing aortic root replacement surgery.

and reinforcing annuloplasty. The final two methods identified are variations on reimplantation. David-IV refers to the technique of using a graft 4 mm larger than the annulus to allow for plication, and David-V employs an even larger graft (6–8 mm larger than the diameter) in order to facilitate the creation of pseudosinuses. Thus, David-I, -IV, and -V are variations on reimplantation, whereas David-II and -III are variations on the remodeling technique originally devised by Yacoub. In the late 1990s through the present day, attention shifted to focus on the finest details in technique, such as cusp reinforcement, graft sizing to allow for billowing, and plication as a means to recreate sinuses.

Dr. Cameron and the group at Johns Hopkins have published some of the largest series on elective repair of patients with connective tissue disorders in need of aortic root surgery [19]. Although a "classic" Bentall (i.e., composite valve-graft replacement) remains the gold standard in their practice, over the years they have introduced valve-sparing procedures when possible.

Their initial valve-sparing approach focused on preservation of sinuses with a remodeling procedure, but it soon became apparent that recurrent aortic insufficiency and annular dilation occurred in a significant number of patients soon after their initial procedure. At their center, as these results began to bear out, they transitioned to the reimplantation technique. This transition coincided with the newly approved De Paulis Valsalva graft and this combination became their exclusive procedure for valve-sparing operations [20].

#### **4.3. Reoperation of the aortic root**

Structural failure of the root, pseudoaneurysms, or infection may necessitate redo aortic root replacement. This is an operation that typically carries a higher risk of mortality and morbidity. Some special considerations include: calcified homografts or stentless valves, coronary artery length, and infection.

**Conflict of interest**

**Author details**

**References**

Ziv Beckerman and Edward P. Chen\*

Medicine, Atlanta, GA, USA

CIR.27.4.779

5637(07)70081-5

S0022-5223(98)70408-8

1016/S1085-5637(07)70080-3

\*Address all correspondence to: edward.p.chen@emory.edu

DOI: 10.1001/jama.1956.72970290003013a

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None.

In patients with a heavily calcified neo-aortic wall it is often extremely difficult to dissect out the wall and redo the root as it becomes very adherent to the adjacent structures and pulmonary artery and coronaries can be injured. Replacing just the aortic valve within the calcified root is an option. With the advent of transaortic valve implantation (TAVI), this may be an option in high risk patients. El-Hamamsy et al. compared the Freestyle graft with homograft aortic root replacement in a prospective, randomized trial, and showed an improved age of survival, lower rate of reoperation, and echocardiographically less signs of valvular deterioration in the Freestyle group [21].

There can be difficulty with mobilizing the coronary buttons and placing them in into the new root or they can be damaged. The Cabrol technique should then be deployed, where a graft is sutured end to end to both the right and left coronary buttons then sutured side to side to the aorta. A second option is to place an interposition vein graft between the coronary buttons and the graft. This is the author's preferred method as we find the grafting to be easier. Lastly bypass-grafting can be done with ligation of the coronary arteries. This is typically a last resort when bleeding and technical difficulties with the anastomosis are encountered.

Infected roots pose a major problem because of the amount of debridement and reconstruction that is required. The same surgical principles apply of removal of all infected and foreign tissue. Results have been promising using homograft replacements as demonstrated in perioperative and with long-term follow-up studies.
