Who needs preoperative routine chest computed tomography for prevention of stroke in cardiac surgery?

Abstract

Although chest computed tomography (CT) is useful for identifying ascending aortic calcification before surgery, the efficacy of routine preoperative CT in cardiac surgery is unknown. We sought to clarify the role of routine preoperative chest CT for the determination of ascending aortic calcification before cardiac surgery to aid in the prevention of stroke. Three hundred consecutive patients who underwent elective cardiac operations excluding thoracic aortic surgery had preoperative non-contrast CT. Thirteen patients (4.3%) had severe calcification in the ascending aorta which required alteration of the cannulation site. Univariate analysis showed preoperative renal dysfunction, dialysis and aortic stenosis as predictors for ascending aortic calcification, but not history of stroke, peripheral vascular disease, and age. In multivariate analysis, aortic stenosis was found as the only predictor. The prevalence of severe ascending aortic calcification was 11.9% (10/84) in patients with aortic stenosis. Stroke occurred in two (0.67%) of the patients in the entire group but none in the 13 patients with surgical modification. For patients with aortic stenosis or hemodialysis, a low postoperative stroke rate can be achieved in elective cardiac surgery by use of routine preoperative chest CT to identify patients with ascending aortic calcification who require modification of the surgical technique.

Distribution of Thoracic Aortic Calcifications in Patients Undergoing Coronary Artery Bypass Grafting

“…In a study by Nishi et al examining aortic calcifications in patients undergoing a variety of cardiac procedures [9], the incidence of severe calcifications (described as porcelain aorta, Type 4 in this study) in the ascending aorta was almost 3-fold higher (1.41% vs. 4.33%) than that in our study. In this previous study, the presence of severe calcifications in the ascending aorta was associated with preoperative renal dysfunction, dialysis, and aortic valve stenosis, although only aortic stenosis emerged as a predictor of severe calcification of the ascending aorta in multivariate analysis [9]. On the other hand, no preoperative parameters had predictive value for severe calcifications of the ascending aorta in our study.…”

“…The presence of severe calcifications in the ascending aorta and aortic arch may alter the course of a scheduled cardiac surgical procedure and is associated with an increased risk of morbidity and mortality [2,8]. A change in the site of cannulation and type of graft upon detection of aortic calcifications after sternotomy may require the use of another myocardial protection technique or intra-aortic balloon occluder [9]. Therefore, these lesions should ideally be identified prior to the surgical procedure to allow readiness for all scenarios.…”

High attenuation pericardial fluid on CT following cardiac catheterization

“…The cohort of clinically stable patients who underwent noncontrast chest CT following CC was largely due to the protocol at our institution of having aortic calcifications assessed by CT prior to surgery requiring aortic cross-clamping [1, 2]. In order to determine a baseline for normal pericardial fluid attenuation, we used a control group of patients who underwent CT prior to the contrast administration during CC.…”

“…Noncontrast CT of the chest is performed frequently at our institution following cardiac catheterization and prior to coronary artery bypass grafting (CABG) or aortic surgery to evaluate for atheromatous aortic plaques and allow for surgical planning [1, 2]. We have observed high- and intermediate-attenuation fluid within the pericardium, and its recesses on CT scans performed soon after catheterization (Figs.…”

Complex Coronary Artery Disease

“…Routine use of screening CT scan in this high risk group is useful to prevent incidence of stroke. [31] CT scan without contrast will delineate the white calcium in clear contrast to the non-calcified aorta which will appear dark. Intraoperatively, epiaortic ultrasound is superior to manual palpation of the ascending aorta and to Transthoracic echocardiography (TEE) for detection of atherosclerosis.…”