**Author details**

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

Prosthesis‐patient mismatch (PPM) is that a smaller than expected effective orifice area (IEOA) in relation to the patient's body surface area (BSA) will result in higher transvalvar gradients. It is condition that occurs when the valve area of a prosthetic valve is less than the area of that patient's normal valve.[46] Several authors suggest that prosthesis-patient mismatch occurs at

below this value, and these elevated gradients potentially cause increased left ventricular work that prevents adequate regression of left ventricular hypertrophy. Several factors including age, body mass index (BMI), and pre-operative status of left ventricular function may poten‐ tially influence the effect of PPM on post-operative outcomes.[46] PPM is associated with a significant reduction in cardiac index during the postoperative course. The incidence of congestive heart failure was significantly higher in patients with PPM.[48] Several studies reported that early mortality is significantly increased in patients with PPM.[47, 48, 49, 50]

The projected indexed EOA should be systematically calculated at the time of the operation to estimate the risk of PPM. PPM can be avoided by using a simple strategy at the time of operation. Pibarot suggested that surgeon first calculate the patient's BSA from his or her

the prosthesis to be implanted should have to avoid PPM, and than choose the prosthesis and

Due to concerns over PPM, stentless bioprosthetic valves, which generally have a larger EOA sizefor- size compared with mechanical or stented bioprosthetic valves, have been increasingly utilized for AVR. In initial evaluation, stentless valves had better hemody‐ namics and improved survival rates relative to stented biological or mechanical valves and were more durable than stented biological valves. Stentless valves may be preferred in patients with a small aortic root, and arguments have been made that wider utilization of stentless valves may minimize PPM. Stentless valves also appear to have better hemo‐ dynamic profiles than stented valves during exercise testing. Technical reasons for not im‐ planting stentless valves include extensive aortic root calcification, coronary ostia opposed by 180, presence of the two coronary ostia in close proximity, or unusual disproportion between the sinotubular junction and the aortic annulus. Whereas stented valves allow

the reference values for the different types and sizes of prosthesis.[46, 47]

/m2

.[46,47] Transvalvular gradients begin to rise substantially at IEOAs

, the result being the minimum EOA that

discharged from the hospital.

374 Calcific Aortic Valve Disease

an IEOA of 0.85 cm<sup>2</sup>

**8. Patient-prosthesis mismatch**

/m2

weight and height. Than multiply BSA by 0.85 cm<sup>2</sup>

Stamenko Šušak1\*, Lazar Velicki1 , Dušan Popović<sup>1</sup> and Ivana Burazor2

