PURPOSE: ECG-gated and contrast enhanced multislice computed tomography (MSCT) is a noninvasive diagnostic tool that permits the visualization of the cardiac structure, including the coronary arteries and bypass grafts that reconstructed in three dimensional image. The purpose of our study was to compare the MSCT with conventional coronary angiography for the evaluation of bypass graft patency following minimally invasive direct coronary artery bypass (MIDCAB).
METHODS: From January 1997 to August 2005, 55 patients underwent MIDCAB with the left internal thoracic artery (LITA) to the left anterior descending coronary artery (LAD) (n=44), with the right gastroepiploic artery (RGEA) to the right posterior descending artery (RPD) (n=3), or with the LITA with a saphenous vein segment extension to the LAD (n=6), the diagonal artery (n=1), or the right acute marginal coronary artery (n=1). Fifty three survived patients were investigated by means of ECG-gated and contrast enhanced 64 MSCT in comparison to coronary angiography performed recently. Survived MIDCAB patients also underwent flow velocity measurement by Doppler ultrasound velocimetry. And graft flows were quantified based on Doppler velocimetric data. All patent grafts were assessable at 64 MSCT and were reassured by flow measurement with Doppler ultrasound.
RESULTS: Patients underwent MIDCAB due to coronary stenosis ((100% occlusion, (n=20) 90 to 99% stenosis, (n=28); <90% stenosis,(n=6)) or unsuccessful percutanlous transcoronary angioplasty with dissection (n=1); There were two patients with LITA to LAD and RGEA to the RPD.Sometimes coronary angiography could not detect the patent ITA graft (n=2). However, all grafts which were patent at coronary angiography were correctly identified at 64 MSCT, with a sensitivity and specificity of 100%, respectively.
CONCLUSION: ECG-gated and contrast enhanced 64 MSCT permits an accurate and non-invasive evaluation of coronary artery bypass patency and could replace the conventional coronary angiography for the follow-up of asymptomatic, stable pts had undergone MIDCAB.
CLINICAL IMPLICATIONS: Technical Constraints MIDCAB:Moving surgical field, No CPB support, Induced ischemia to construct graft, OR extubation Port-Access, Camera-assisted visualization, Elongated instruments, Progressively smaller incisions, Femoral CPB support.
DISCLOSURE: Tsung Tsai, None.