Preoperative evaluation for aortic surgery

1. Preoperative evaluation for aortic surgery Inter-hospital Conference 20(2/2554) Aortic surgery: Update & Decision making วันเสาร์ที่  17  กันยายน 2554ห้องประชุมสมาคมศิษย์เก่าแพทย์ศิริราช โรงพยาบาลศิริราช

2. 4. Imaging Modalities4.1. Recommendations for Aortic ImagingTechniques 1. Measurements of aortic diameter should be taken at reproducible anatomic landmarks, perpendicular to the axis of blood flow, and reported in a clear and consistent format (see Table 5). (Level of Evidence: C) 2. For measurements taken by computed tomographic imaging or magnetic resonance imaging, the external diameter should be measured perpendicular to the axis of blood flow. For aortic root measurements, the widest diameter, typically at the mid-sinus level, should be used. (Level of Evidence: C) 3. For measurements taken by echocardiography, the internal diameter should be measured perpendicular to the axis of blood flow. For aortic root measurements, the widest diameter, typically at the midsinus level, should be used. (Level of Evidence: C)

3. Selection of the imaging studypatient-related factors Institutional capabilities • Radiation exposure

4. CXR • Other causes of patient’s symptom • sensitivity of a widened mediastinum or an abnormal aortic contour associated with significant thoracic aortic disease at 64% and 71%, respectively

5. CXR

6. CT scan

10. MRI • sensitivities and specificities are equivalent to CT a • multiplanar evaluation • identify anatomic variants of AoD (IMH and PAU) • branch artery involvement • aortic valve pathology and left ventricular dysfunction • without exposing to radiation or iodinated contrast • prolonged duration • Gadolinium- renal insufficiency

11. Angiography • site of dissection, branch artery involvement, and communication of the true and false lumens • coronary artery and aortic branch (visceral and limb artery) disease, as well as assessment of aortic valve and left ventricular function

12. Disadvantages • 1) not being universally available because it requires the presence of an experienced physician to perform the study • 2) being an invasive procedure that is time consuming and requires exposure to iodinated contrast • 3) having poor ability to diagnose IMH given a lack of luminal disruption • 4) potentially producing false negative results when a thrombosed false lumen prevents adequate

13. Echocardiography • suprasternal view • left (and sometimes right) parasternal projection • TEE is superior to TTE for assessment of the thoracic aorta

14. Echocardiographic Criteria for ThoracicAortic Aneurysms • aortic dilatation • suggests the underlying etiology of the aortic disease (eg, bicuspid aortic valve)

16. Echocardiographic Criteria for Aortic Dissection • dissection flap • dissection flap has a motion independent of surrounding structures • differential flow on the 2 sides of the dissection flap • True lumen – systole, little or no SEC • False lumen – diastole, SEC, complete or partial thrombosis • pericardial effusion

17. right and left ventricular function • myocardial ischemia • 2 coronary arteries • acute aortic regurgitation