**7. Operative technique**

In some studies of patients followed over longer time frames, freedom from all valve-related events and freedom from reoperation were improved in patients with mechanical valve prostheses as compared to patients with biological prostheses. [9,16,25] Key of long-term success of mechanical valve prostheses is anticoagulation. Patients that are inconsistent, noncompliant or incapable of managing medications are not good candidates for long-term chronic anticoagulation.[39,41] Also patients with higher levels of education and those from geographic areas with a good medical infrastructure have better compliance with necessary

Many centers used bioprosthetic valves for patients who are older than 70 year, based on data by Akins.[42] In patients younger than 60 years of age, the best solution would be implantation of mechanical valves, based on prosthesis durability and they have low-risk for valve-related events.[21] In decade between 60 and 70 years of age, other factors have to be taken into

receive a biologic valve. Patients under the age of 60 should have a mechanical prosthesis to minimize the risk of structural failure requiring repeat AVR in an octogenarian. Patients between 60 and 65 represent the group in whom there is still considerable debate regarding prosthesis selection. Those patients who have comorbidities such as severe CAD may be less likely to outlive their prosthesis and should receive a biologic valve. A detailed discussion of these risks and benefits of prosthesis selection should occur with all patients and their families

In the early follow-up period, anticoagulation – related hemorrhage is the most common unwanted event for mechanical valve prostheses. Over the first 10 years of follow-up there is a higher incidence of valve-related events in patients with mechanical prostheses as opposed to those with biologic valves.[32] However, in the next 10 to 20 years after AVR, the incidence of valve failure and valve-related complications are much higher at biologic prostheses than those with mechanical valve prostheses. Some series showed that the time to biologic valve failure was only 7.6 years.[43] This failure rate will increase over time. However, freedom from valve-related events is more strongly influenced by pre-existing comorbidities than the

The elderly patient with severe aortic stenosis poses a therapeutic challenge. In considering elderly patients for aortic valve replacement, important factors include the presence of symptoms, physiologic age, patient expectations, anticipated future activities, and comorbid‐ ity. The operation itself carries a higher risk than in younger patients. Extensive calcification of the aorta and annulus as well as fragile tissue presents significant technical difficulties for the surgeon. In addition, particularly in women, the aortic root and annulus may be small and require concomitant enlargement to accommodate the valve prosthesis. Furthermore, pro‐ truding arch atheroma occurs in one-fifth of patients *>* 65 years of age and significantly increases the risk of stroke and mortality during cardiac surgery. Major postoperative complications, nevertheless, remain high, with the incidence of permanent stroke between 4 and 6%. Rehabilitation can also be a problem, as elderly patients take longer to recover from surgery. Survival has clearly improved in these elderly patients with severe symptomatic aortic stenosis who undergo aortic valve replacement. Survival is 80–85% at 1 year and 60–

According to some studies, patients over 65 years at the time of surgery should

medications and anticoagulant monitoring.[31]

prior to entering the operating room. [3,7,22,24,25,37,38]

presence of mechanical prostheses.[21], [22, 25, 31]

account.7

372 Calcific Aortic Valve Disease

Aortic valve replacement is most frequently done through a median sternotomy, meaning the incision is made by cutting through the sternum. Once the pericardium has been opened, the patient is put on a cardiopulmonary bypass machine. This machine takes over the task of breathing for the patient and pumping their blood around while the surgeon replaces the heart valve.

Once the patient is on bypass, a cut is made in the aorta and a crossclamp applied. The surgeon then removes the patient`s diseased aortic valve and a mechanical or biological valve is put in its place. Once the valve is in place and aorta has been closed, the patient is taken off the heartlung machine. Transesophageal echocardiogram can be used to verify that the new valve is functioning property. Pacing wires are usually put in place, so that the heart can be manually paced should any complications arise after surgery. Drainage tubes are also inserted to drain fluids from the chest and pericardium following surgery. These are usually removed within 36-48 hours while the pacing wires are generally left in place until right before the patient is discharged from the hospital.

perfect valve mounting within the aortic annulus, thus reducing the risk of implanting an incompetent valve, postoperative AR and limited durability remain a concern with the free-hand stentless valve insertion technique. This issue may be circumvented with full

[1] Malouf, J. F, Edwards, W. D, Tajik, A. J, & Seward, J. Functional anatomy of the heart. In: Fuster V, O'Rourke RA, Walsh RA, Poole-Wilson P, eds. Hurst's The Heart.

[2] Otto, C. M, Lind, B. K, Kitzman, D. W, et al. Association of aortic valve sclerosis with cardiovascular mortality and morbidity in the elderly. N Eng J Med (1999).

[3] Andrew WangThomas S. Bashore. Valvular Heart Disease. Humana Press, a part of

[4] Gjertsson, P, Caidahl, K, Farasati, M, et al. Preopeartive moderate to severe diastolic dysfunction: A novel Doppler echocardiographic long-term prognosis factor in pa‐

[5] Connolly, H. M, Oh, J. K, Orszulak, T. A, et al. Aortic valve replacement for aortic stenosis with severe left ventricular dysfunction: prognostic indicators. Circulation

[6] Gjertsson, P, Caidahl, K, & Bech-hanssen, O. Left ventricular diastolic dysfunction late after aortic valve replacement in patients with aortic stenosis. Am J Cardiol

[7] Bonow, R. O, Carabello, B. A, & Chatterjee, K. de Leon AC Jr, Faxon DP, Freed MD, Gaasch WH, Lytle BW, Nishimura RA, O'Gara PT, O'Rourke RA, Otto CM, Shah PM, Shanewise JS. ACC/AHA 2006 guidelines for the management of patients with valv‐ ular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Develop

and Ivana Burazor2

Surgical Valve Replacement (Bioprosthetic VS Mechanical)

http://dx.doi.org/10.5772/53687

375

, Dušan Popović<sup>1</sup>

1 Institute of Cardiovascular Diseases Vojvodina, Sremska Kamenica, Serbia

12th ed. New York, NY: McGraw-Hill Companies, Inc; (2008).

tients with severe aortic stenosis. J Thorac Cardiovasc Surg (2005).

Springer Science Business Media, LLC (2009).

aortic root replacement using a stentless porcine root.[3.49,50]

\*Address all correspondence to: drsusak@gmail.com

**Author details**

**References**

Stamenko Šušak1\*, Lazar Velicki1

2 Clinical Centers, Nis, Serbia

(1997). , 95, 2395-400.

(2005). , 96, 722-7.
