Multidetector-computed tomography for coronary artery operation planning: evaluation of the method

Abstract

Background: Planning of coronary artery bypass grafting (CABG) in severe three-vessel-disease (3-CAD) needs three-dimensional (3D) information. We evaluated spiral multidetector-computed tomography (MDCT) as surgical planning tool. Methods: A total of 450 coronary segments was evaluated. The study (30 patients) used MDCT (Siemens, Somatom Plus 4 VZ, retrospective gating). 3D-reconstructions were used to score both, suitability for coronary anastomosis, and stenosis quantification. Influence of reconstruction time, heart rate, slice thickness (1.25 vs. 3 mm) was evaluated. Coronary angiography (angio) was carried out in each patient. Scorings were performed by three observers. Results: Temporal resolution was 170 ms. Mean sensitivity for correct bypass indication was 27.9% (1.25/3.0-mm slices: 22.2/17.1%), specificity 85.0% (93.5/88.9%). For detecting stenosis, sensitivity reached 32.3% (35.5/34.7%), specificity 88.5% (88.9/87.3%). Maximum κ-coefficient for MDCT was 0.25 (angio: 0.40). Visibility was best at reconstruction time 400 ms, heart rate <80 beats per minute, bpm ( p<0.0001 vs. >80 bpm), slice thickness of 3 mm ( p<0.05 vs. 1.25 mm). Agreement of stenosis grading was 48.9 %. Conclusions: Operation planning of CABG is facilitated using MDCT by providing data of high specificity. MDCT fails to provide reliable data on stenosis quantification. Interobserver variability is high. Modern cardiac surgery (navigation, robotics) may be facilitated.