Begemann P G, Arnold M, Detter C, Boehm D H, Ittrich H, Koops A, Reichenspurner H, Adam G, Weber C
Klinik und Poliklinik für Diagnostische und Interventionelle Radiologie, Radiologisches Zentrum, Universitätsklinikum, Hamburg.
Rofo. 2005 Aug;177(8):1084-92. doi: 10.1055/s-2005-858369.
Minimal invasive direct coronary artery bypass grafting (MIDCAB) or off-pump coronary artery bypass grafting (OPCAB) on the beating heart with full or mini-sternotomy are becoming more common in coronary bypass surgery of the left anterior descending (LAD). In the decision, which surgical approach (MIDCAB, OPCAB or conventional surgery with cardiopulmonary bypass) will be best used, knowledge of the anatomical field is of major importance. The aim of the study was to evaluate retrospective ECG-gated 4-row multidetector CT (MDCT) in patients planned for MIDCAB as additional imaging to coronary angiography.
The study included 25 consecutive patients. MSCT was performed as unenhanced (collimation 4 x 2.5 mm) and contrast-enhanced examination (140-170 ml, 300 mg Iodine/ml, collimation 4 x 1 mm). The evaluation included presence of LAD calcifications, distance of LAD and left internal mammarian artery (LIMA), course of LAD and LIMA, the presence or absence of bridging through myocardium or epicardial fat and the presence of pleural fibrosis. The MDCT results were correlated with intra-operative findings.
All MDCTs could be assessed with reference to the demands. In 20/25 operations, MDCT had direct influence as to the selection of the surgical approach (11 MIDCAB, 7 OPCAB with mini-sternotomy and 5 with full sternotomy, 2 conventional surgeries). The distance of LAD and LIMA varied from 0.9 to 4.5 cm in MDCT. As to calcifications, 3/25 correlated patients had calcifications and 10 patients had no calcifications in the middle LAD. Seven patients had intraoperative fibrosis of the vessel wall without calcification of the middle LAD, which could not be detected with MDCT. Another 5 patients had single calcified plaques in the middle LAD, 4 of these had a fibrosis of the vessel and 1 had a normal vessel at surgery. In these cases, the anastomosis was done between the calcified plaques. No myocardial bridging was detected by MDCT and at surgery. Bridging of epicardial fat was shown by MDCT and at surgery in 9/25 patients and was excluded in 15 patients. In 1 patient, the LAD seemed to run superficially in MDCT, but was covered with fat as seen during surgery. The course of the LIMA was inconspicuous in all cases, no pleural fibrosis was found.
The 4-row MDCT has proven to be adequate in addition to coronary angiography for preoperative evaluation in patients scheduled for MIDCAB and provides the surgeon with relevant information for the selection of the operative approach.
在左前降支（LAD）冠状动脉搭桥手术中，采用全胸骨切开或小切口在跳动心脏上进行微创直接冠状动脉搭桥术（MIDCAB）或非体外循环冠状动脉搭桥术（OPCAB）越来越普遍。在决定采用哪种手术方式（MIDCAB、OPCAB或体外循环常规手术）最为合适时，了解解剖区域至关重要。本研究的目的是评估回顾性心电图门控4排多层螺旋CT（MDCT）在计划行MIDCAB患者中的应用，作为冠状动脉造影的补充成像方法。
本研究纳入25例连续患者。MDCT检查包括平扫（准直4×2.5mm）和增强扫描（140 - 170ml，300mg碘/ml，准直4×1mm）。评估内容包括LAD钙化情况、LAD与左乳内动脉（LIMA）的距离、LAD和LIMA的走行、心肌或心外膜脂肪搭桥的有无以及胸膜纤维化情况。MDCT结果与术中发现进行相关性分析。
所有MDCT检查均可根据要求进行评估。在20/25例手术中，MDCT对手术方式的选择有直接影响（11例MIDCAB，7例小切口OPCAB和5例全胸骨切开OPCAB，2例常规手术）。MDCT显示LAD与LIMA的距离在0.9至4.5cm之间。关于钙化情况，25例相关患者中有3例LAD中段有钙化，10例无钙化。7例患者术中发现血管壁纤维化但LAD中段无钙化，MDCT未检测到。另外5例患者LAD中段有单个钙化斑块，其中4例手术时血管有纤维化，1例血管正常。在这些病例中，吻合在钙化斑块之间进行。MDCT及手术中均未检测到心肌桥。9/25例患者MDCT及手术中显示有心外膜脂肪搭桥，15例排除。1例患者MDCT显示LAD走行表浅，但手术中可见被脂肪覆盖。所有病例中LIMA走行均不明显，未发现胸膜纤维化。
4排MDCT已被证明除冠状动脉造影外，对计划行MIDCAB患者的术前评估是足够的，并为外科医生选择手术方式提供相关信息。
