International Journal of Vascular Medicine
Volume 2016 (2016), Article ID 4726094, 6 pages
http://dx.doi.org/10.1155/2016/4726094

Review Article

Imaging Techniques for Diagnosis of Thoracic Aortic Atherosclerosis

Wouter W. Jansen Klomp,1,2 George J. Brandon Bravo Bruinsma,³ Arnoud W. van ’t Hof,² Jan. G. Grandjean,⁴ and Arno P. Nierich⁵

¹Department of Cardiology, Isala Clinics, Dokter van Heesweg 2, 8025 AB Zwolle, Netherlands
²Department of Clinical Epidemiology, Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, P.O. Box 85500, 3508 GA Utrecht, Netherlands
³Cardiothoracic Surgery, Isala Clinics, Dokter van Heesweg 2, 8025 AB Zwolle, Netherlands
⁴Department of Cardiothoracic Surgery, Koningsplein 1, 7512 KZ Enschede, Netherlands
⁵Anaesthesiology and Intensive Care, Isala Clinics, Dokter van Heesweg 2, 8025 AB Zwolle, Netherlands

Received 30 September 2015; Accepted 13 January 2016

Academic Editor: Mark Morasch

Copyright © 2016 Wouter W. Jansen Klomp et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract.

The most severe complications after cardiac surgery are neurological complications including stroke which is often caused by emboli merging from atherosclerosis in the ascending aorta to the brain. Information about the thoracic aorta is crucial in reducing the embolization risk for both surgical open and closed chest procedures such as transaortic heart valve implantation. Several techniques are available to screen the ascending aorta, for example, transesophageal echocardiography (TEE), epiaortic ultrasound, TEE A-view method, manual palpation, computed tomography, and magnetic resonance imaging. This paper provides a description of the advantages and disadvantages of these imaging techniques.

1. Introduction

Neurological complications including stroke are amongst the dreaded complications of cardiothoracic surgery. The incidence of stroke reported in previous studies varied from 1.6% to 17% [1–7]. This wide range may be explained by two factors. First, it has been shown that different definitions of stroke and different strategies to establish the diagnosis greatly impact the incidence; a structured diagnostic protocol for stroke was shown to result in a doubled incidence [7]. Second, the occurrence of stroke is a multifactorial process, and the individual stroke risk depends on multiple pre- and perioperative factors, which include age, female gender, previous cerebrovascular disease, diabetes mellitus, prior heart surgery, prior vascular surgery, history of pulmonary disease, impaired left ventricular function, type of surgery, CPB time, and aortic atherosclerosis [2, 8–12].

2. Role of Aortic Atherosclerosis in Neurological Complications

From a pathophysiological perspective, particulate emboli originating from aortic atheroma have been shown to play a pivotal role in the occurrence of postoperative neurological complications [13–18]. Histopathology of emboli captured with an intra-aortic filter showed that 85% of emboli consisted of fibrous atheroma or cap [19]. Also, an autopsy study including 262 patients who died after cardiac surgery showed that cerebral circulatory disturbances were present in 49% of the brains, which primarily consisted of (micro) infarction, followed by cerebral and subarachnoidal haemorrhage; however, the incidence of generalized hypoxemia was low (1.9–2.7% if heart transplant was excluded) [20]. The cause of death was considered to be of primary cerebral aetiology in 12.9% of patients [20].

Stroke is the most evident clinical characteristic after cerebral embolization, but the occurrence of postoperative cognitive dysfunction (PCD), delirium, and dementia may be associated with cerebral emboli. Indeed, presence of aortic atherosclerosis has been associated with an increased risk of postoperative stroke [2, 9–12], postoperative cognitive dysfunction [21], renal dysfunction [22], and mortality [23, 24].

3. Imaging Techniques of the (Distal) Ascending Aorta

3.1. TEE

Several guidelines have been developed to recommend the position of perioperative use of transesophageal echocardiography in cardiac surgery. Whereas in earlier guidelines TEE was recommended primarily in more complicated procedures (e.g., valve and dissection) [25–27], more recent guidelines recommend its use in all cardiac and thoracic aortic surgeries [28–31]. Detailed descriptions of the technique and views that should be obtained have previously been described [29, 31–33]. Assessment of the thoracic aorta for atherosclerosis or aortic wall pathology constitutes part of this standard examination.

TEE can be performed after induction of anesthesia and before sternotomy, which offers more time from diagnosis of atherosclerosis to the actual change in the surgical management than epiaortic ultrasound. TEE allows adequate visualization of the proximal ascending aorta and thoracic descending aorta [34, 35]. However, visualization of the distal ascending aorta and its branches is hampered by the so-called blind spot caused by the air-filled trachea which interposes the oesophagus and aorta [36, 37]. A meta-analysis of diagnostic accuracy studies showed that the sensitivity of TEE in the diagnosis of severe atherosclerosis of the DAA was a mere 21% [36]. This caveat of TEE was also recognized in the aforementioned guidelines [28, 29, 36].

3.2. Epiaortic Ultrasound

In epiaortic ultrasound (EAU) imaging, accurate visualization of the ascending aorta, both proximal and distal, is possible with the direct application of an echo probe onto the aorta. However, visualization of the arch and the origins of the cerebral vessels is limited by anatomic borders such as the pericardium. This method is considered as the gold standard for visualization of the distal ascending aorta [35]. Its use is recommended in patients with an increased stroke risk, such as patients with prior cerebral or vascular disease, and in patients with evidence of atherosclerosis based on other diagnostic tests [38]. Also, EAU can be used as an alternative test in patients with a contraindication for TEE and has not been associated with complications itself, although some concerns have been raised regarding interference with the surgical field. Since EAU requires sternotomy, it can only be applied in a later stage of the operation compared to TEE [38]. Also optimal EAU visualization of the distal ascending aorta, aortic arch, and its branches is performed with the pericardium still closed since opening of the pericardium will reduce visualization of the arch and its side branches.

Screening for aortic atherosclerosis with EAU has been shown to result in changes of the surgical management in 4.1–31% in patients undergoing cardiac surgery [39–43]. Also, several retrospective cohort studies suggested a reduction in stroke [43, 44] and POCD [45], associated with changes in the surgical management after EAU screening. Djaiani et al. included 113 patients in a randomized comparison of screening for atherosclerosis by TEE with manual palpation or the addition of EAU and found that although the surgical management changed more frequently in the EAU group (12% versus 29%, ), the incidence of cerebral emboli and cognitive dysfunction was similar in both groups. The most frequent change in the surgical plan was an adjustment of the cannulation site (), followed by distal arch cannulation (), fibrillary arrest (), and change to OPCAB (). However, aortic arch imaging was limited by only TEE monitoring of the distal arch and left subclavian artery, probably resulting in underestimation of atherosclerosis.

Multiple guidelines recommended the use of EAU in (high-risk) cardiothoracic surgery [33, 37, 38]. Its use is diminishing however since TEE is often the preferred test as this allows for continuous monitoring and does not interfere with the surgical procedure [37].

3.3. Modified TEE or the TEE A-View Method

A-View (Aortic View) technique has been developed to eliminate this so-called blind spot to be used as an additional diagnostic tool prior to cardiac surgery. A modification of TEE has been shown to accurately diagnose aortic atherosclerosis of the DAA, through the placement of a balloon positioned in the trachea, which provides an echocardiographic window to the aorta after inflation with saline [46–48]. The method allows also visualization of the aortic arch and the origins of the cerebral arteries. Therefore, a complete interrogation of the thoracic aorta and branch vessels can be achieved before surgical incision or sternotomy.

After conventional TEE imaging, during which the thoracic aorta is visualized as good as possible, the A-View balloon is introduced into the trachea and left main bronchus and inflated with saline after preoxygenation of the patient. During a period of apnoea, the remaining part of the thoracic aorta, that is, the distal ascending aorta, aortic arch, and its branches can be visualized [46–48]. Compared to EAU, modified TEE had a good overall diagnostic accuracy (area under the receiver operating curve [AUC] of 0.89) for atherosclerosis of the DAA grade 3 or greater, with a positive predictive value (PPV) of 67% and negative predictive value (NPV) of 97% [48]. Also, the diagnosis improved beyond patient characteristics and conventional TEE imaging [49] (atheromatous disease of the aorta was defined by grading the disease using the Katz classification: Grade 1, normal-appearing intima of the aorta, Grade 2, extensive intimal thickening, Grade 3, sessile atheroma protruding <5 mm into the aorta, Grade 4, atheroma protruding >5 mm, and Grade 5, mobile atheroma) [50].

Compared to EAU, modified TEE has the advantage to be performed before the start of the operation. Important decision time for the surgeon is gained in making the right decision in treatment strategy by discussing the patient risk factors and TEE diagnostic information including atherosclerosis before incision. In 12% of the procedures, surgical adaptions were applied, mostly based on change of cannulation site (38%). Also EAU was frequently added to supplement the modified TEE examination giving a more direct guided visualization of the plaque with a more detailed view due to the high frequency probe used in EAU. Implementing the so-called Isala safety check reduced mortality from 2010 till 2013 each year with 15% in the presumed low risk procedures such as CABG, AVR, and combined AVR-CABG [51].

3.4. Manual Palpation

Although manual palpation for aortic plaques is routinely performed, it is well known that presence of atherosclerosis is underestimated using this method with sensitivity of 21% [52–54], which also results in fewer changes in the surgical management compared to EAU (see Section 3.2) [42]. The lesions most likely to be missed are noncalcified plaques, which are on the contrary most likely to cause distal embolization. Furthermore, it is conceivable that the manipulation itself causes plaque disturbance. Therefore, we do not consider manual palpation to be of value in the diagnosis of aortic atherosclerosis.

3.5. Computed Tomography

Although this paper focuses on the diagnosis of atherosclerosis during surgery, preoperative screening for aortic atherosclerosis can also be achieved using computed tomography (CT) or magnetic resonance imaging (MRI) [55].

The diagnostic accuracy of computed tomography compared to TEE for the presence of aortic atherosclerosis was studied in 47 stroke patients; CT angiography had low sensitivity (52.6%) compared to TEE with positive and negative predictive values of 84.6% and 75.8%, respectively [56]. Another study similarly showed that presence of aortic atherosclerosis was underestimated with CT imaging compared to EAU, with poor reliability between the two methods (kappa: 0.45) [57]. This would imply that CTA is not a good test to exclude aortic atherosclerosis, which could be related to the limited ability to detect (noncalcified) soft plaques. This hypothesis was not addressed in these studies however. Of note, a smaller study () showed good correlation between aortic arch atheroma thickness diagnosed with CT and TEE imaging (Pearson’s : 0.82) [58].

Although the diagnostic accuracy of CT imaging appears to be inferior to EAU and TEE imaging, its results do have prognostic consequences. A “total plaque burden score” calculated from multidetector-row CT angiography (MDCTA) prior to cardiothoracic surgery was associated with increased all-cause mortality; atherosclerosis located in the ascending but not in the descending aorta was an independent predictor [59]. Another study, which included 141 patients planned for minimally invasive mitral valve surgery without sternotomy, showed that in 30 patients multidetector CT (MDCT) screening resulted in a change in the final approach, primarily because of visualization of aortoiliac atherosclerosis. In 29 patients a (partial) sternotomy was performed, while in one patient surgery was cancelled [60]. Also, a retrospective cohort study using a historical comparison group suggested that implementation of preoperative noncontrast CT screening in patients with an increased stroke risk resulted in a reduction of stroke and mortality [61].

The more timely diagnosis of aortic atherosclerosis with CT compared to (modified) TEE and EAU is an important advantage, as this provides more time to plan changes in the surgical management. Disadvantages however are beside a logistic burden, a nephrotoxic risk, and radiation exposure. Moreover, since CT imaging cannot be performed during surgery, the intraoperative guidance of (subtle) changes in the surgical management and continuous monitoring during surgery are impossible. Therefore, although CT imaging may have an important role in specific procedures (e.g., TAVR or minimally invasive MVR) in which the aortic anatomy is also of importance, (modified) TEE or EAU is preferable for the detection of aortic atherosclerosis.

3.6. Magnetic Resonance Imaging

Using MR imaging various aspects of aortic atheroma can be characterized, including fibrous cap, lipid core, and thrombus [62]. Several studies compared the diagnosis of aortic atheroma with MRI to TEE [63, 64]. In 99 patients with cryptogenic stroke, the imaging quality (defined as the percentage of the wall circumference assessable with a high level of confidence) of MRI was shown to be superior compared to TEE in the ascending aorta and aortic arch, which was attributed to air artefacts [64]. A good imaging quality of the ascending aorta was observed in 7% and 73% of interrogations with TEE and MR imaging, respectively (), although TEE quality was superior for the descending aorta. Accordingly, magnetic resonance imaging showed more complex plaques compared to TEE in the ascending aorta (13 versus 7, ), aortic arch (37 versus 11, ), and descending aorta (101 versus 70, ).

Despite the advantages of MRI, its use in general practice is limited because of several limitations, including current imaging times, availability, costs, and the lack of intraoperative imaging.

4. Conclusion

A complete examination of the thoracic aorta is important to guide surgical decision making in treatment algorithms. Information about the thoracic aorta is crucial in reducing the embolization risk for both surgical open and closed chest procedures such as transaortic heart valve implantation.

All imaging modalities do contribute to diagnostic imaging; however, only echo provides real time imaging during the different phases of treatment. If conventional TEE imaging quality is insufficient, additional screening with modified TEE or epiaortic ultrasound is advised. The choice for either test depends on availability and operator experience. Modified TEE has the advantage to be performed before surgical incision, when changes in surgical management or a crossover to a nonsurgical management can still be considered.

Conflict of Interests

The authors declare that there is no conflict of interests regarding the publication of this paper.

References

G. H. Almassi, T. Sommers, T. E. Moritz et al., “Stroke in cardiac surgical patients: determinants and outcome,” Annals of Thoracic Surgery, vol. 68, no. 2, pp. 391–398, 1999.

J. D. Van der Linden, L. Hadjinikolaou, P. Bergman, and D. Lindblom, “Postoperative stroke in cardiac surgery is related to the location and extent of atherosclerotic disease in the ascending aorta,” Journal of the American College of Cardiology, vol. 38, no. 1, pp. 131–135, 2001.

J. Bucerius, J. F. Gummert, M. A. Borger et al., “Stroke after cardiac surgery: a risk factor analysis of 16,184 consecutive adult patients,” Annals of Thoracic Surgery, vol. 75, no. 2, pp. 472–478, 2003.

P. A. Barber, S. Hach, L. J. Tippett, L. Ross, A. F. Merry, and P. Milsom, “Cerebral ischemic lesions on diffusion-weighted imaging are associated with neurocognitive decline after cardiac surgery,” Stroke, vol. 39, no. 5, pp. 1427–1433, 2008.

H. P. Grocott and T. Tran, “Aortic atheroma and adverse cerebral outcome: risk, diagnosis, and management options,” Seminars in Cardiothoracic and Vascular Anesthesia, vol. 14, no. 2, pp. 86–94, 2010.

C. W. Hogue Jr., S. F. Murphy, K. B. Schechtman, and V. G. Dávila-Román, “Risk factors for early or delayed stroke after cardiac surgery,” Circulation, vol. 100, no. 6, pp. 642–647, 1999.

S. R. Messé, M. A. Acker, S. E. Kasner et al., “Stroke after aortic valve surgery: results from a prospective cohort,” Circulation, vol. 129, no. 22, pp. 2253–2261, 2014.

M. F. Newman, R. Wolman, M. Kanchuger et al., “Multicenter preoperative stroke risk index for patients undergoing coronary artery bypass graft surgery. Multicenter Study of Perioperative Ischemia (McSPI) Research Group,” Circulation, vol. 94, no. 9, pp. II74–II80, 1996.

J. Van der Linden, P. Bergman, and L. Hadjinikolaou, “The topography of aortic atherosclerosis enhances its precision as a predictor of stroke,” Annals of Thoracic Surgery, vol. 83, no. 6, pp. 2087–2092, 2007.

G. S. Hartman, F.-S. F. Yao, M. Bruefach III et al., “Severity of aortic atheromatous disease diagnosed by transesophageal echocardiography predicts stroke and other outcomes associated with coronary artery surgery: a prospective study,” Anesthesia & Analgesia, vol. 83, no. 4, pp. 701–708, 1996.

G. Djaiani, L. Fedorko, M. Borger et al., “Mild to moderate atheromatous disease of the thoracic aorta and new ischemic brain lesions after conventional coronary artery bypass graft surgery,” Stroke, vol. 35, no. 9, pp. e356–358, 2004.

S. E. Elias-Smale, A. E. Odink, R. G. Wieberdink et al., “Carotid, aortic arch and coronary calcification are related to history of stroke: the Rotterdam study,” Atherosclerosis, vol. 212, no. 2, pp. 656–660, 2010.

R. Dittrich and E. B. Ringelstein, “Occurrence and clinical impact of microembolic signals during or after cardiosurgical procedures,” Stroke, vol. 39, no. 2, pp. 503–511, 2008.

M. A. Borger, J. Ivanov, R. D. Weisel, V. Rao, and C. M. Peniston, “Stroke during coronary bypass surgery: principal role of cerebral macroemboli,” European Journal of Cardio-Thoracic Surgery, vol. 19, no. 5, pp. 627–632, 2001.

G. N. Djaiani, “Aortic arch atheroma: stroke reduction in cardiac surgical patients,” Seminars in Cardiothoracic and Vascular Anesthesia, vol. 10, no. 2, pp. 143–157, 2006.

V. R. Challa, D. M. Moody, and B. T. Troost, “Brain embolic phenomena associated with cardiopulmonary bypass,” Journal of the Neurological Sciences, vol. 117, no. 1-2, pp. 224–231, 1993.

R. F. Gottesman, G. M. McKhann, and C. W. Hogue, “Neurological complications of cardiac surgery,” Seminars in Neurology, vol. 28, no. 5, pp. 703–715, 2008.

D. M. Moody, W. R. Brown, V. R. Challa, D. A. Stump, D. M. Reboussin, and C. Legault, “Brain microemboli associated with cardiopulmonary bypass: a histologic and magnetic resonance imaging study,” The Annals of Thoracic Surgery, vol. 59, no. 5, pp. 1304–1307, 1995.

P. Bergman, L. Hadjinikolaou, and J. Van der Linden, “Aortic atheroma is related to number of particulates captured by intra-aortic filtration in CABG,” European Journal of Cardio-thoracic Surgery, vol. 22, no. 4, pp. 539–544, 2002.

P. Emmrich, J. Hahn, V. Ogunlade, K. Geiger, R. Schober, and F. W. Mohr, “Neuropathological findings after cardiac surgery—retrospective study over 6 years,” Zeitschrift für Kardiologie, vol. 92, no. 11, pp. 925–937, 2003.

L. A. Evered, B. S. Silbert, and D. A. Scott, “Postoperative cognitive dysfunction and aortic atheroma,” Annals of Thoracic Surgery, vol. 89, no. 4, pp. 1091–1097, 2010.

V. G. Dávila-Román, N. T. Kouchoukos, K. B. Schechtman, and B. Barzilai, “Atherosclerosis of the ascending aorta is a predictor of renal dysfunction after cardiac operations,” Journal of Thoracic and Cardiovascular Surgery, vol. 117, no. 1, pp. 111–116, 1999.

V. G. Dávila-Román, S. F. Murphy, N. J. Nickerson, N. T. Kouchoukos, K. B. Schechtman, and B. Barzilai, “Atherosclerosis of the ascending aorta is an independent predictor of long-term neurologic events and mortality,” Journal of the American College of Cardiology, vol. 33, no. 5, pp. 1308–1316, 1999.

S. K. Thambidorai, S. J. Jaffer, T. K. Shah, W. J. Stewart, A. L. Klein, and M. S. Lauer, “Association of atheroma as assessed by intraoperative transoesophageal echocardiography with long-term mortality in patients undergoing cardiac surgery,” European Heart Journal, vol. 28, no. 12, pp. 1454–1461, 2007.

M. D. Cheitlin, W. F. Armstrong, G. P. Aurigemma et al., “ACC/AHA/ASE 2003 guideline update for the clinical application of echocardiography: summary article: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/ASE Committee to Update the 1997 Guidelines for the Clinical Application of Echocardiography),” Circulation, vol. 108, pp. 1146–1162, 2003.

N. Kolev, R. Brase, J. Swanevelder et al., “The influence of transoesophageal echocardiography on intra-operative decision making A European multicentre study,” Anaesthesia, vol. 53, no. 8, pp. 767–773, 1998.

D. Schmidlin, D. Bettex, E. Bernard et al., “Transoesophageal echocardiography in cardiac and vascular surgery: implications and observer variability,” British Journal of Anaesthesia, vol. 86, no. 4, pp. 497–505, 2001.

American Society of Anesthesiologists and Society of Cardiovascular Anesthesiologists Task Force on Transesophageal Echocardiography, “Practice guidelines for perioperative transesophageal echocardiography. An updated report by the American Society of Anesthesiologists and the Society of Cardiovascular Anesthesiologists Task Force on Transesophageal Echocardiography,” Anesthesiology, vol. 112, no. 5, pp. 1084–1096, 2010.

F. A. Flachskampf, L. Badano, W. G. Daniel et al., “Recommendations for transoesophageal echocardiography: update 2010,” European Journal of Echocardiography, vol. 11, no. 7, pp. 557–576, 2010.

F. A. Flachskampf, P. F. Wouters, T. Edvardsen et al., “Recommendations for transoesophageal echocardiography: EACVI update 2014,” European Heart Journal Cardiovascular Imaging, vol. 15, no. 4, pp. 353–365, 2014.

R. T. Hahn, T. Abraham, M. S. Adams et al., “Guidelines for performing a comprehensive transesophageal echocardiographic examination: recommendations from the American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists,” Anesthesia & Analgesia, vol. 118, no. 1, pp. 21–68, 2014.

S. T. Reeves, A. C. Finley, N. J. Skubas et al., “Basic perioperative transesophageal echocardiography examination: a consensus statement of the american society of echocardiography and the society of cardiovascular anesthesiologists,” Journal of the American Society of Echocardiography, vol. 26, no. 5, pp. 443–456, 2013.

C. A. Troianos, G. S. Hartman, K. E. Glas et al., “Guidelines for performing ultrasound guided vascular cannulation: recommendations of the American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists,” Journal of the American Society of Echocardiography, vol. 24, no. 12, pp. 1291–1318, 2011.

M. J. Wilson, S. Y. N. Boyd, P. G. Lisagor, B. J. Rubal, and D. J. Cohen, “Ascending aortic atheroma assessed intraoperatively by epiaortic and transesophageal echocardiography,” The Annals of Thoracic Surgery, vol. 70, no. 1, pp. 25–30, 2000.

K. E. Glas, M. Swaminathan, S. T. Reeves et al., “Guidelines for the performance of a comprehensive intraoperative epiaortic ultrasonographic examination: recommendations of the American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists; endorsed by the Society of Thoracic Surgeons,” Journal of the American Society of Echocardiography, vol. 20, no. 11, pp. 1227–1235, 2007.

B. Van Zaane, N. P. A. Zuithoff, J. B. Reitsma, L. Bax, A. P. Nierich, and K. G. M. Moons, “Meta-analysis of the diagnostic accuracy of transesophageal echocardiography for assessment of atherosclerosis in the ascending aorta in patients undergoing cardiac surgery,” Acta Anaesthesiologica Scandinavica, vol. 52, no. 9, pp. 1179–1187, 2008.

S. T. Reeves, K. E. Glas, H. Eltzschig et al., “Guidelines for performing a comprehensive epicardial echocardiography examination: recommendations of the american society of echocardiography and the society of cardiovascular anesthesiologists,” Anesthesia and Analgesia, vol. 105, no. 1, pp. 22–28, 2007.

K. E. Glas, M. Swaminathan, S. T. Reeves et al., “Guidelines for the performance of a comprehensive intraoperative epiaortic ultrasonographic examination: recommendations of the American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists; endorsed by the Society of Thoracic Surgeons,” Anesthesia & Analgesia, vol. 106, no. 5, pp. 1376–1384, 2008.

V. G. Davila-Roman, B. Barzilai, T. H. Wareing, S. F. Murphy, and N. T. Kouchoukos, “Intraoperative ultrasonographic evaluation of the ascending aorta in 100 consecutive patients undergoing cardiac surgery,” Circulation, vol. 84, no. 5, pp. III47–III53, 1991.

H. B. Hangler, G. Nagele, M. Danzmayr et al., “Modification of surgical technique for ascending aortic atherosclerosis: impact on stroke reduction in coronary artery bypass grafting,” Journal of Thoracic and Cardiovascular Surgery, vol. 126, no. 2, pp. 391–400, 2003.

G. Bolotin, Y. Domany, L. de Perini et al., “Use of intraoperative epiaortic ultrasonography to delineate aortic atheroma,” Chest, vol. 127, no. 1, pp. 60–65, 2005.

G. Djaiani, M. Ali, M. A. Borger et al., “Epiaortic scanning modifies planned intraoperative surgical management but not cerebral embolic load during coronary artery bypass surgery,” Anesthesia & Analgesia, vol. 106, no. 6, pp. 1611–1618, 2008.

P. Rosenberger, S. K. Shernan, M. Löffler et al., “The influence of epiaortic ultrasonography on intraoperative surgical management in 6051 cardiac surgical patients,” Annals of Thoracic Surgery, vol. 85, no. 2, pp. 548–553, 2008.

B. Zingone, E. Rauber, G. Gatti et al., “The impact of epiaortic ultrasonographic scanning on the risk of perioperative stroke,” European Journal of Cardio-Thoracic Surgery, vol. 29, no. 5, pp. 720–728, 2006.

A. G. Royse, C. F. Royse, A. E. Ajani et al., “Reduced neuropsychological dysfunction using epiaortic echocardiography and the exclusive Y graft,” Annals of Thoracic Surgery, vol. 69, no. 5, pp. 1431–1438, 2000.

B. van Zaane, A. P. Nierich, W. F. Buhre, G. J. Brandon Bravo Bruinsma, and K. G. M. Moons, “Resolving the blind spot of transoesophageal echocardiography: a new diagnostic device for visualizing the ascending aorta in cardiac surgery,” British Journal of Anaesthesia, vol. 98, no. 4, pp. 434–441, 2007.

A. P. Nierich, B. van Zaane, W. F. Buhre, J. Coddens, A. J. Spanjersberg, and K. G. M. Moons, “Visualization of the distal ascending aorta with A-mode transesophageal echocardiography,” Journal of Cardiothoracic and Vascular Anesthesia, vol. 22, no. 5, pp. 766–773, 2008.

B. Van Zaane, A. P. Nierich, G. J. B. B. Bruinsma et al., “Diagnostic accuracy of modified transoesophageal echocardiography for pre-incision assessment of aortic atherosclerosis in cardiac surgery patients,” British Journal of Anaesthesia, vol. 105, no. 2, pp. 131–138, 2010.

W. W. Jansen Klomp, L. M. Peelen, S. J. Spanjersberg et al., “Added value of modified transoesophageal echocardiography in the diagnosis of atherosclerosis of the distal ascending aorta in cardiac surgery patients,” European Heart Journal Cardiovascular Imaging, vol. 15, no. 6, pp. 623–630, 2014.

E. S. Katz, P. A. Tunick, H. Rusinek, G. Ribakove, F. C. Spencer, and I. Kronzon, “Protruding aortic atheromas predict stroke in elderly patients undergoing cardiopulmonary bypass: experience with intraoperative transesophageal echocardiography,” Journal of the American College of Cardiology, vol. 20-21, no. 1, pp. 70–77, 1992.

A. P. Nierich, “Effects of the introduction of a cardiac surgery safety checklist on 30 day mortality and operative team culture: a cohort study,” Journal of Cardiothoracic and Vascular Anesthesia, vol. 29, supplement 2, p. S46, 2015.

S. Sylivris, C. Levi, G. Matalanis et al., “Pattern and significance of cerebral microemboli during coronary artery bypass grafting,” Annals of Thoracic Surgery, vol. 66, no. 5, pp. 1674–1678, 1998.

A. G. Royse and C. F. Royse, “Epiaortic ultrasound assessment of the aorta in cardiac surgery,” Best Practice and Research: Clinical Anaesthesiology, vol. 23, no. 3, pp. 335–341, 2009.

S. Sylivris, P. Calafiore, G. Matalanis et al., “The intraoperative assessment of ascending aortic atheroma: epiaortic imaging is superior to both transesophageal echocardiography and direct palpation,” Journal of Cardiothoracic and Vascular Anesthesia, vol. 11, no. 6, pp. 704–707, 1997.

J. M. Gottsegen and N. L. Coplan, “The atherosclerotic aortic arch: considerations in diagnostic imaging,” Preventive Cardiology, vol. 11, no. 3, pp. 162–167, 2008.

N. Benyounes, S. Lang, J. Savatovsky et al., “Diagnostic performance of computed tomography angiography compared with transesophageal echocardiography for the detection and the analysis of aortic atheroma,” International Journal of Stroke, vol. 8, no. 5, p. E22, 2013.

P. Bergman, J. van der Linden, K. Forsberg, and M. Ohman, “Preoperative computed tomography or intraoperative epiaortic ultrasound for the diagnosis of atherosclerosis of the ascending aorta?” The Heart Surgery Forum, vol. 7, no. 3, pp. E245–E249, 2004.

S. I. Hussain, R. C. Gilkeson, J. I. Suarez et al., “Comparing multislice electrocardiogram-gated spiral computerized tomography and transesophageal echocardiography in evaluating aortic atheroma in patients with acute ischemic stroke,” Journal of Stroke and Cerebrovascular Diseases, vol. 17, no. 3, pp. 134–140, 2008.

V. Kurra, M. L. Lieber, S. Sola et al., “Extent of thoracic aortic atheroma burden and long-term mortality after cardiothoracic surgery: a computed tomography study,” JACC: Cardiovascular Imaging, vol. 3, no. 10, pp. 1020–1029, 2010.

S. Moodley, P. Schoenhagen, A. M. Gillinov et al., “Preoperative multidetector computed tomograpy angiography for planning of minimally invasive robotic mitral valve surgery: impact on decision making,” Journal of Thoracic and Cardiovascular Surgery, vol. 146, no. 2, pp. 262.e1–268.e1, 2013.

R. Lee, N. Matsutani, A. C. Polimenakos, L. C. Levers, M. Lee, and R. G. Johnson, “Preoperative noncontrast chest computed tomography identifies potential aortic emboli,” Annals of Thoracic Surgery, vol. 84, no. 1, pp. 38–42, 2007.

T. Thenappan, J. Ali Raza, and A. Movahed, “Aortic atheromas: current concepts and controversies—a review of the literature,” Echocardiography, vol. 25, no. 2, pp. 198–207, 2008.

Z. A. Fayad, T. Nahar, J. T. Fallon et al., “In vivo magnetic resonance evaluation of atherosclerotic plaques in the human thoracic aorta: a comparison with transesophageal echocardiography,” Circulation, vol. 101, no. 21, pp. 2503–2509, 2000.

A. Harloff, S. M. Brendecke, J. Simon et al., “3D MRI provides improved visualization and detection of aortic arch plaques compared to transesophageal echocardiography,” Journal of Magnetic Resonance Imaging, vol. 36, no. 3, pp. 604–611, 2012.