Intraoperative epiaortic ultrasound during cardiac surgery

Background and Aims: Recent evidence suggests that the incidence of stroke during cardiac surgery may be reduced by using intraoperative epiaortic ultrasound (IEU) to detect ascending aortic atherosclerosis (AAA). To better define the role of this modality, IEU was performed in 89 patients during elective cardiac procedures. Methods: The ascending aorta and proximal arch were divided into four segments that were graded (0 to 2) on the extent of disease both by palpation and IEU. A patient score (range 0 to 8) was determined for each modality by summing the segmental scores. Operative plan was determined in part by IEU findings. Preoperative variables were evaluated for associated risk of AAA. Palpation and IEU scores were compared for their ability to identify AAA. Results: Operative technique was modified to avoid AAA in ten (11.2%) patients (mean age 68.3 +/- 2.2 years; mean IEU score = 4.40 +/- 0.40). Stroke occurred in two patients (2.2%), one whose operation was modified to avoid severe AAA and another who had minimal AAA. Mean IEU scores were significantly higher for patients greater than or equal to 65 years compared with younger patients (1.35 +/- 0.26 vs 0.66 +/- 0.21; p < 0.05) and for smokers compared with nonsmokers (1.15 +/- 0.19 vs 0 +/- 0; p < 0.05). Mean patient IEU score was greater than mean palpation score (1.06 +/- 0.18 vs 0.74 +/- 0.16; p < 0.05). Sensitivity of palpation (based on 356 segments) was 0.46; however, specificity was 0.96, predictive power of a negative palpation exam was 0.88, and overall accuracy of palpation was 0.86. Thirty of the 38 false negatives resulted from failure to detect 1+ disease. None of the 63 (71%) patients with a palpation score of zero required a technical modification or had a stroke. Conclusions: These data suggest that AAA may be more severe in older patients and smokers. Aortic palpation may not identify mild AAA. IEU can confirm and clearly define both the extent and distribution of suspected AAA and is useful for determining optimal operative strategy in patients with aortic disease.