*3.13.7.3 Procedures*

*Advances in Complex Valvular Disease*

patient cohort concerning TAVI treatment.

*3.13.7.2 Management of aortic regurgitation*

It is also highly recommended to take into account the morphology of the device

Surgical aortic valve replacement remains the standard gold treatment of aortic valve regurgitation (AR). Transcatheter aortic valve implantation (TAVI) plays only a minor role. Currently, the JenaValve (JenaValve Technology GmbH, Munich, Germany) is the only prosthesis available for pure AR as an investigational device [61]. All other prostheses are used off label [61]. Concerning the choice of the type of prosthesis, criteria used in aortic stenosis are not merely interchangeable. The percentage of oversizing has to be calculated in a different way because of the absence annular calcification. Although outcomes have improved with newer-generation TAVI devices outcomes are still inferior to surgery. In a few circumstances, TAVI might be an option for patients with severe AR and high surgical risk.

The class I recommendations for aortic valve intervention, in patients with AR according to the 2014 American College of Cardiology and the American Heart Association are the following: symptomatic patients with chronic severe AR, asymptomatic patients with chronic severe AR and LV dysfunction (ejection fraction < 50%) at rest, and patients with chronic severe AR who are undergoing concomitant coronary artery bypass grafting, aortic surgery, or other heart valve surgery. The class IIa recommendation is for patients with asymptomatic AR and normal LV systolic function (ejection fraction > 50%) but with severe LV dilation (endsystolic diameter > 50 mm). The class IIb recommendation is for patients with moderate AR who are undergoing coronary artery bypass grafting, aortic surgery, or other heart valve surgery. Aortic valve intervention may also be reasonable in asymptomatic patients with chronic severe AR, normal LV systolic function, and severe LV dilation (end-diastolic diameter > 65 mm) if the operative risk is low. Other considerations can include evidence of progressive LV dilation, declining exercise tolerance, or abnormal hemodynamic response to exercise [62, 63].

However, aortic valve repair carries a similar, if not lower, risk of perioperative complication with a low risk of valve-related events over time. Similar to mitral valve repair for mitral regurgitation, six there is some suggestion that aortic valve intervention should be considered earlier in patients in whom aortic valve repair is likely [64]. Another broad category of patients who undergo aortic valve preservation and

repair are those with primary aortic pathology involving the aortic root or the ascending aorta and varying degrees of associated aortic valvular disease. In these patients, the primary indication for intervention is driven by aortic size, discussed

From a technical perspective, all patients with primary aortic insufficiency are potential candidates for repair. However, the success of aortic valve repair is determined largely by the quality of cusp tissue available. Thus, patients with significant leaflet calcification, destruction owing to active endocarditis, or rheumatic involvement are least likely to undergo successful and durable aortic valve repair. In contrast, repair has been shown to have good results in patients with bicuspid (and in smaller series, unicuspid, and quadricuspid aortic valves), despite the abnormalities in cusp anatomy. An important limitation to the universal application of aortic valve repair techniques is the lack of surgical expertise and experience in this field; however, this is changing rapidly with increasing interest in aortic valve repair. Patients who are candidates for repair should be referred to centres with appropriate expertise.

in the American, European, and Canadian Guidelines.

For asymptomatic patients with an indication for aortic valve replacement, surgical replacement is still the gold standard, because no data are available for this

landing zone and the resulting individual risks for TAVI procedures.

**30**

Surgery of the aortic valve can now be accomplished with greater safety and efficacy in the majority of patients. In patients with higher operative risks, TAVI is already a proven acceptable alternative to AVR. The choice of valve prosthesis is guided by patient preference, life expectancy, and comorbidities relevant to SVD and anticoagulation. Aortic valve repair in the young patient with AR avoids the risks associated with valve prostheses, but long-term durability is unknown. Aortic root surgery similarly can be performed with the replacement of both the aortic valve and aortic wall, but valve-sparing techniques may offer the advantage of durability equivalent to that of normal native aortic valves with avoidance of prosthetic valve-related complications. Reoperative aortic valve and aortic root surgery, like isolated AVR, can be performed safely with best outcomes at high-volume centres.

Aortic valve replacement (AVR) is becoming safe despite the elderly population of patients is now being treated, with the best outcomes achieved at high-volume centres. The standard approach is a median sternotomy aortic valve and aortic root replacement. However, minimally invasive approaches, including the upper hemisternotomy and right anterior thoracotomy (**Figure 4**), can be performed with equivalent safety and better outcomes. The use of stented bioprosthetic valves surpassed the use of mechanical valves, homografts, and pulmonary autografts combined, reflecting advances in valve technology. The Novel Sutureless valves combine the advantages of a surgical AVR procedure (control of aortic atheroemboli, resection of the diseased native valve) with transcatheter technique (decreased procedure time, improved valve hemodynamic function). Bentall procedure: root replacement with a composite valve-graft is the gold standard for aortic root aneurysm (**Figure 5**). However, for patients who want to avoid the long-term oral anticoagulation required for mechanical valves and structural valve deterioration of the bioprosthetic valves, valve-sparing aortic root replacement (David or Yacoub procedures) is a good option (**Figure 6**).

Indications for aortic root replacement include aneurysms of the ascending aorta, aortic valve endocarditis with annular abscess, and acute type A aortic dissection. The most common indication is an aneurysm of the aortic root or ascending aorta. The size threshold for aneurysm repair depends on whether the aneurysm is the primary indication for surgery or whether it coexists in a patient already requiring cardiac surgery.

**Figure 4.** *Aortic valve replacement.*

**Figure 5.** *Bio Bentall procedures.*

Primary aneurysms of the aortic root are secondary to either genetically mediated disorders or acquired disorders. The acquired disorders include degenerative thoracic aortic aneurysm, chronic aortic dissection, intramural hematoma, penetrating atherosclerotic ulcer, mycotic aneurysm, and pseudoaneurysm. The size threshold for surgical repair in this group of patients is 5.5 cm for both the aortic root and ascending aorta according to class I recommendations by the 2010 ACC/AHA Guidelines for the Diagnosis and management of Patients with Thoracic Aortic Disease developed by a multigroup-sponsored task force [65]. The genetically mediated disorders include Marfan syndrome, vascular Ehlers-Danlos syndrome, Turner syndrome, BAV, familial thoracic aortic aneurysm and dissection, and Loeys-Dietz syndrome. These disorders are associated with a greater risk of rupture, dissection, and death, in particular Loeys-Dietz syndrome. The size threshold for operative intervention in this group of patients is 5.0 cm, according to the same guidelines [51]. This recommendation is consistent with a size threshold of 5.0 cm in patients with BAV in the 2006 ACC/AHA Guidelines for the Management of Patients with Valvular Heart Disease [9]. Surgical repair may be considered

**33**

**Figure 7.**

*Aortic Valve Disease: State of the Art*

ment of existing bypass grafts.

aortic stenosis [68].

specific to TAVI.

failed bioprostheses [70].

*Current commonly implanted TAVI valves.*

dures performed per operator are required.

*DOI: http://dx.doi.org/10.5772/intechopen.93311*

depending on imaging modality [66].

in patients with Loeys-Dietz syndrome and aortic diameters as small as 4.2 cm,

Reoperative aortic valve and aortic root surgery can also be performed safely, utilisation CT/MRI imaging, meticulous myocardial protection, and safe manage-

Two devices of aortic valves for percutaneous transcatheter aortic valve implantation (TAVI) have been used in a large number of patients: balloon-expandable and self-expanding. Many new valve technologies are in development [67] (**Figure 7**). Current data from randomised trials confirmed that TAVI is superior to medical therapy in patients with prohibitive risks for surgery, and it is equivalent to surgical aortic valve replacement in high-risk and medium-risk patients with

TAVI is technically possible in most patients with aortic stenosis. The larger question is when should TAVI be offered? Evaluation should identify patients in whom a significant improvement in quality and duration of life is likely and avoid unnecessary intervention in patients in whom the procedure can be performed, but the benefit is unlikely. For this reason evaluation of neurocognitive functioning, frailty, functional status, mobility, and social support is important in patient selection [68]. Transthoracic and transesophageal echocardiography, cardiac computed tomography, and invasive angiography are all used to perform anatomic evaluations

Evaluation of appropriate candidates for TAVI requires a non-competitive team approach involving interventional cardiologists with expertise in structural heart disease, cardiac and vascular surgeons, anesthesiologists, imaging specialists, and specialised nurses. The proper equipment and a minimum volume of TAVI proce-

Randomised trials and large registries of TAVI indicate procedural success rates of more than 95%, 30-day survival of more than 90%, meaningful improvement in the quality of life, and acceptable complication rates (procedure-related stroke < 2%, vascular access site complications < 5%, permanent pacemaker rates < 5%) [69]. Experience with TAVI within failed bioprostheses (valve-in-valve procedures) has been reported. Critical issues in achieving a successful valve-in-valve procedure include an understanding of the manufacturer sizing and labelling of surgical bioprostheses and correct positioning of the valve in the valve. Early experience suggests that TAVI will be an important option for the treatment of patients with

More than 100,000 TAVI procedures have been performed to date. Alternatives

to TAVI include surgical aortic valve replacement, aortic balloon valvuloplasty (with or without external beam radiation), and apical-to-aortic conduits.

### *Aortic Valve Disease: State of the Art DOI: http://dx.doi.org/10.5772/intechopen.93311*

*Advances in Complex Valvular Disease*

**Figure 5.**

**Figure 6.** *Valve sparing repair.*

Primary aneurysms of the aortic root are secondary to either genetically mediated disorders or acquired disorders. The acquired disorders include degenerative thoracic aortic aneurysm, chronic aortic dissection, intramural hematoma, penetrating atherosclerotic ulcer, mycotic aneurysm, and pseudoaneurysm. The size threshold for surgical repair in this group of patients is 5.5 cm for both the aortic root and ascending aorta according to class I recommendations by the 2010 ACC/AHA Guidelines for the Diagnosis and management of Patients with Thoracic Aortic Disease developed by a multigroup-sponsored task force [65]. The genetically mediated disorders include Marfan syndrome, vascular Ehlers-Danlos syndrome, Turner syndrome, BAV, familial thoracic aortic aneurysm and dissection, and Loeys-Dietz syndrome. These disorders are associated with a greater risk of rupture, dissection, and death, in particular Loeys-Dietz syndrome. The size threshold for operative intervention in this group of patients is 5.0 cm, according to the same guidelines [51]. This recommendation is consistent with a size threshold of 5.0 cm in patients with BAV in the 2006 ACC/AHA Guidelines for the Management of Patients with Valvular Heart Disease [9]. Surgical repair may be considered

*Bio Bentall procedures.*

**32**

in patients with Loeys-Dietz syndrome and aortic diameters as small as 4.2 cm, depending on imaging modality [66].

Reoperative aortic valve and aortic root surgery can also be performed safely, utilisation CT/MRI imaging, meticulous myocardial protection, and safe management of existing bypass grafts.

Two devices of aortic valves for percutaneous transcatheter aortic valve implantation (TAVI) have been used in a large number of patients: balloon-expandable and self-expanding. Many new valve technologies are in development [67] (**Figure 7**).

Current data from randomised trials confirmed that TAVI is superior to medical therapy in patients with prohibitive risks for surgery, and it is equivalent to surgical aortic valve replacement in high-risk and medium-risk patients with aortic stenosis [68].

TAVI is technically possible in most patients with aortic stenosis. The larger question is when should TAVI be offered? Evaluation should identify patients in whom a significant improvement in quality and duration of life is likely and avoid unnecessary intervention in patients in whom the procedure can be performed, but the benefit is unlikely. For this reason evaluation of neurocognitive functioning, frailty, functional status, mobility, and social support is important in patient selection [68].

Transthoracic and transesophageal echocardiography, cardiac computed tomography, and invasive angiography are all used to perform anatomic evaluations specific to TAVI.

Evaluation of appropriate candidates for TAVI requires a non-competitive team approach involving interventional cardiologists with expertise in structural heart disease, cardiac and vascular surgeons, anesthesiologists, imaging specialists, and specialised nurses. The proper equipment and a minimum volume of TAVI procedures performed per operator are required.

Randomised trials and large registries of TAVI indicate procedural success rates of more than 95%, 30-day survival of more than 90%, meaningful improvement in the quality of life, and acceptable complication rates (procedure-related stroke < 2%, vascular access site complications < 5%, permanent pacemaker rates < 5%) [69].

Experience with TAVI within failed bioprostheses (valve-in-valve procedures) has been reported. Critical issues in achieving a successful valve-in-valve procedure include an understanding of the manufacturer sizing and labelling of surgical bioprostheses and correct positioning of the valve in the valve. Early experience suggests that TAVI will be an important option for the treatment of patients with failed bioprostheses [70].

More than 100,000 TAVI procedures have been performed to date. Alternatives to TAVI include surgical aortic valve replacement, aortic balloon valvuloplasty (with or without external beam radiation), and apical-to-aortic conduits.

**Figure 7.** *Current commonly implanted TAVI valves.*

### *3.13.7.4 Outcomes*

Data from the STS indicates that the operative mortality for patients 70 years of age or older who underwent isolated AVR or AVR with coronary artery bypass grafting surgery (CABG) between 1994 and 2003 fell from 10% to less than 6% [71]. In the most recent analysis using the STS database on 108,687 patients from 1997 to 2006 with a mean age of 68 years undergoing isolated AVR, the in-hospital mortality was 2.6% with an observed stroke rate of 1.3% and length of stay of 7.8 days for the year 2006. Among patients 80–85 years of age, 30-day mortality was 4.9% with an observed stroke rate of 2.0%.

Experience at centres of excellence within the last 5 years has demonstrated significantly improved operative mortality, less than 1%, after isolated AVR. The incidence of perioperative stroke in these contemporary series ranged from 0% to 1.9%, and the length of stay was as short as 5 days [72].

In the prospective, randomised, multicenter Placement of Aortic Transcatheter Valves (PARTNER) trial comparing high-risk patients (mean STS score 11.8%) receiving TAVI or AVR for severe, symptomatic AS, outcomes for both procedures were excellent [73]. Patients undergoing AVR (n = 351, mean age 85 years) had a 30-day mortality of 6.5%, setting a new benchmark for operative outcomes in a high-risk cohort of patients treated at centres of excellence [74]. Moreover, comparative results showed that early and late strokes and transient ischemic attacks were significantly lower in the AVR group than the TAVI group (30 days, 2.4% vs. 5.5%, respectively, P = 0.04; 1 year, 4.3% vs. 8.3%, respectively, P = 0.04) [75].

Freedom from reoperation depends on both the prosthesis and patient age. Although they do not degenerate, modern mechanical valves do have a finite reoperation rate of 0.5–1% per year from endocarditis, pannus overgrowth, and thrombosis. Actual freedom from reoperation of modern bioprostheses at 15 years approaches 100% in elderly patients older than 70 years, but it can be as low as 50% in patients younger than 50 years.

### *3.13.7.5 Complications*

The most common complications following aortic valve surgery are similar to those of other cardiac surgeries and include stroke (1–4%), deep sternal wound infection (1–2%), reoperation for bleeding (1–3%), and myocardial infarction (MI; 1–5%). Transient heart block is not uncommon, presumably as a result of traction or oedema of the bundle of His in the vicinity of the right noncoronary commissure. It usually resolves within 5–6 days of surgery. The risk of complete heart block requiring pacemaker insertion is 3–5% [76].
