*4.1.1 Beta blockers*

The use of beta blockers has shown a survival benefit in patients with aortic root dilation secondary to Marfan syndrome [101]. While data on survival benefits for patients with bicuspid aortic valves is sparse, the common practice is to also prescribe beta blockers given that both conditions share a similar pathology and therefore both are likely to benefit from beta blockade. The mechanism by which beta blockers slow the progression of aortic root dilation is through their negative inotropic and chronotropic effects, reducing the peak left ventricular ejection rate and therefore decreasing shear stress and the rate of aortic dilation [102].

## *4.1.2 Other agents for blood pressure control*

The goal blood pressure for patients with thoracic aortic aneurysms is <130/80 mmHg. In patients who cannot tolerate beta blockers, calcium channel blockers (CCB) are an alternative group of medications available. While less studied as compared to beta blockers, CCB have also been found to reduce the rate of aortic root dilation [103]. Other agents that can be used for additional blood pressure control include ACE-inhibitors and ARBs.

### *4.1.3 Management of other cardiovascular risk factors*

In order to reduce the risk for complications such as aortic dissection, patients should be counseled on smoking cessation, and cessation of drugs that increase aortic wall stress such as cocaine or other stimulants. In addition patients should have dyslipidemia well controlled, which can be achieved through the use of atorvastatin 40–80 mg daily in individuals with aortic root aneurysms [104, 105].

#### *4.1.4 Lifestyle modifications and pregnancy*

Patients should be counseled on avoiding high intensity and collision sports, such as boxing and cycling. Instead patients should take part in low dynamic sports, such as, golf [5, 106]. Pregnancy should be avoided in patients with Marfan syndrome with an aortic diameter >40 mm, if a patient does chose to become pregnant however there must be close follow up with surveillance imaging of the aortic diameter [5, 101].

#### **4.2 Surgical management**

#### *4.2.1 Indications for surgery*

Emergent surgical interventions are indicated for management of an aortic dissection or rupture, or a symptomatic aneurysm. In addition, surgical repair can be performed electively in high risk patients to prevent propagation of an aneurysm (**Table 3**). Indications for elective surgical intervention include the absolute size of the aneurysm—if the diameter is over 55 mm, or over 50 mm in patients with Marfan syndrome or bicuspid valves. Other indications for elective surgery include if the rate

**13**

*Diagnosis and Surveillance of Aortic Root Dilation DOI: http://dx.doi.org/10.5772/intechopen.86329*

• Symptomatic aortic root dilation (may represent an impeding rupture)

**Emergent surgical repair Elective surgical repair**

*Indications for emergent and elective surgical repair of aortic root dilation.*

*4.2.2 Surgical interventions*

• Aortic rupture • Aortic dissection

**Table 3.**

of growth of an aneurysm surpasses 10 mm/year, and if there is concurrent aortic insufficiency [1, 100]. In addition, patients who undergo aortic insufficiency repair who have concurrent aortic root dilation should be considered for aortic replacement at the time of their surgery—that is since 25% of patients with aortic root diameters >40 mm will eventually also require intervention for their aortic aneurysm [107].

• Aortic dilation >55 mm

syndrome or bicuspid valves • Rate of growth >10 mm/year

diameter of aortic dilation)

• Aortic dilation >50 mm in individuals with Marfan

• Aortic insufficiency (decision largely based on

As opposed to supravalvular aortic aneurysms, aortic root aneurysms involve the coronary ostia as well as the aortic valve, which have implications on the type of surgical procedure available for patients. There are two approaches for a surgical intervention: radical and conservative. In a radial surgical intervention the patient's aortic valve and root are replaced (commonly referred to as the Bentall procedure),

The Bentall procedure involves replacing the aortic valve with a prosthetic valve, and thus has the caveat of requiring indefinite anticoagulation [5]. If patients have a high bleeding risk it may therefore be worthwhile investigating replacement of the aortic root while preserving the valve. In addition, it is important to note that a large number of patients with aortic root dilation are young (secondary to its association with Marfan syndrome), and therefore lifelong anticoagulation in cases such as these confers a cumulative bleeding risk. Preserving the aortic valve while surgically treating the aortic root dilatation is made possible by the development of two surgical procedures: the first is removing the aortic root while keeping the valve intact. The second method is through re-implantation of the aortic valve [5]. Both the Bentall procedure as well as aortic valve-preserving procedures have been shown to have comparable short and long-term outcomes with regards to the risk of death and valve associated complications. The main difference however is that patients undergoing valve sparing operations were significantly more likely to

In patients with both severe aortic stenosis and ascending aortic aneurysm, undergoing surgical aortic valve replacement (sAVR) and concomitant surgical intervention for aortic aneurysms above 4.5 cm is recommended by the American College of Cardiology (ACC) foundation guidelines [84]. However, in high-risk surgical patients, undergoing a transcatheter aortic valve replacement (TAVR) has become an alternative approach that obviates the need for parallel surgical aortic aneurysm intervention. This raises the concern for the safety of TAVR catheterbased delivery system in patients with aortic aneurysms since intraoperative rupture or dissection risk potentially increases. However, a clinical study showed that TAVR does not increase intraoperative aortic dissection/rupture risk or mortality with a median follow-up of 14 months [109]. Therefore, there are no recommendations against performing TAVR in patients with ascending aortic aneurysms.

whereas in conservative interventions only the aortic root is replaced [108].

develop moderate to severe aortic regurgitation later [108].

*Diagnosis and Surveillance of Aortic Root Dilation DOI: http://dx.doi.org/10.5772/intechopen.86329*


#### **Table 3.**

*Aortic Aneurysm and Aortic Dissection*

management [1, 100].

*4.1.1 Beta blockers*

**4.1 Medical management**

*4.1.2 Other agents for blood pressure control*

control include ACE-inhibitors and ARBs.

*4.1.4 Lifestyle modifications and pregnancy*

**4.2 Surgical management**

*4.2.1 Indications for surgery*

*4.1.3 Management of other cardiovascular risk factors*

symptoms and size of the aneurysm. For patients who are asymptomatic and have root dilation <55 mm, medical management is advised. In patients with Marfan syndrome or a bicuspid aortic valve, the cut off of ≤50 mm is used for medical

The use of beta blockers has shown a survival benefit in patients with aortic root dilation secondary to Marfan syndrome [101]. While data on survival benefits for patients with bicuspid aortic valves is sparse, the common practice is to also prescribe beta blockers given that both conditions share a similar pathology and therefore both are likely to benefit from beta blockade. The mechanism by which beta blockers slow the progression of aortic root dilation is through their negative inotropic and chronotropic effects, reducing the peak left ventricular ejection rate

and therefore decreasing shear stress and the rate of aortic dilation [102].

The goal blood pressure for patients with thoracic aortic aneurysms is <130/80 mmHg. In patients who cannot tolerate beta blockers, calcium channel blockers (CCB) are an alternative group of medications available. While less studied as compared to beta blockers, CCB have also been found to reduce the rate of aortic root dilation [103]. Other agents that can be used for additional blood pressure

In order to reduce the risk for complications such as aortic dissection, patients should be counseled on smoking cessation, and cessation of drugs that increase aortic wall stress such as cocaine or other stimulants. In addition patients should have dyslipidemia well controlled, which can be achieved through the use of atorvastatin

Patients should be counseled on avoiding high intensity and collision sports, such as boxing and cycling. Instead patients should take part in low dynamic sports, such as, golf [5, 106]. Pregnancy should be avoided in patients with Marfan syndrome with an aortic diameter >40 mm, if a patient does chose to become pregnant however there must be close follow up with surveillance imaging of the aortic diameter [5, 101].

Emergent surgical interventions are indicated for management of an aortic dissection or rupture, or a symptomatic aneurysm. In addition, surgical repair can be performed electively in high risk patients to prevent propagation of an aneurysm (**Table 3**). Indications for elective surgical intervention include the absolute size of the aneurysm—if the diameter is over 55 mm, or over 50 mm in patients with Marfan syndrome or bicuspid valves. Other indications for elective surgery include if the rate

40–80 mg daily in individuals with aortic root aneurysms [104, 105].

**12**

*Indications for emergent and elective surgical repair of aortic root dilation.*

of growth of an aneurysm surpasses 10 mm/year, and if there is concurrent aortic insufficiency [1, 100]. In addition, patients who undergo aortic insufficiency repair who have concurrent aortic root dilation should be considered for aortic replacement at the time of their surgery—that is since 25% of patients with aortic root diameters >40 mm will eventually also require intervention for their aortic aneurysm [107].

### *4.2.2 Surgical interventions*

As opposed to supravalvular aortic aneurysms, aortic root aneurysms involve the coronary ostia as well as the aortic valve, which have implications on the type of surgical procedure available for patients. There are two approaches for a surgical intervention: radical and conservative. In a radial surgical intervention the patient's aortic valve and root are replaced (commonly referred to as the Bentall procedure), whereas in conservative interventions only the aortic root is replaced [108].

The Bentall procedure involves replacing the aortic valve with a prosthetic valve, and thus has the caveat of requiring indefinite anticoagulation [5]. If patients have a high bleeding risk it may therefore be worthwhile investigating replacement of the aortic root while preserving the valve. In addition, it is important to note that a large number of patients with aortic root dilation are young (secondary to its association with Marfan syndrome), and therefore lifelong anticoagulation in cases such as these confers a cumulative bleeding risk. Preserving the aortic valve while surgically treating the aortic root dilatation is made possible by the development of two surgical procedures: the first is removing the aortic root while keeping the valve intact. The second method is through re-implantation of the aortic valve [5]. Both the Bentall procedure as well as aortic valve-preserving procedures have been shown to have comparable short and long-term outcomes with regards to the risk of death and valve associated complications. The main difference however is that patients undergoing valve sparing operations were significantly more likely to develop moderate to severe aortic regurgitation later [108].

In patients with both severe aortic stenosis and ascending aortic aneurysm, undergoing surgical aortic valve replacement (sAVR) and concomitant surgical intervention for aortic aneurysms above 4.5 cm is recommended by the American College of Cardiology (ACC) foundation guidelines [84]. However, in high-risk surgical patients, undergoing a transcatheter aortic valve replacement (TAVR) has become an alternative approach that obviates the need for parallel surgical aortic aneurysm intervention. This raises the concern for the safety of TAVR catheterbased delivery system in patients with aortic aneurysms since intraoperative rupture or dissection risk potentially increases. However, a clinical study showed that TAVR does not increase intraoperative aortic dissection/rupture risk or mortality with a median follow-up of 14 months [109]. Therefore, there are no recommendations against performing TAVR in patients with ascending aortic aneurysms.
