Buxton B F, Ruengsakulrach P, Fuller J, Rosalion A, Reid C M, Tatoulis J
Department of Cardiac Surgery, Austin Campus, HSB-5, Austin & Repatriation Medical Centre, Studley Road, Victoria 3084, Heidelberg, Australia.
Eur J Cardiothorac Surg. 2000 Sep;18(3):255-61. doi: 10.1016/s1010-7940(00)00527-3.
The left internal thoracic artery (LITA), when grafted to the left anterior descending artery (LAD), is generally accepted as the conduit of choice for coronary artery bypass grafting (CABG). In contrast, the role and efficacy of the right internal thoracic artery (RITA), despite its long-term use as a coronary artery graft, is relatively less understood. Accordingly, in this study, we sought to assess the utility of the RITA as a coronary conduit by examining the long-term patency of both in situ and free RITA grafts and analyzing the association between intraoperative graft and coronary artery variables.
Nine hundred and sixty-two patients (LITA 962, RITA 432) who had CABG between 1985 and 1998 and underwent re-angiography for evidence of myocardial ischemia were included in this observational analysis. The diameter of the internal thoracic artery (ITA), the presence of a proximal anastomosis with the aorta, the location of the anastomosis with the coronary artery, and the coronary artery diameter, were recorded at the initial procedure. The follow-up was 67.0+/-39.4 months (mean+/-SD, range 0.1-169.5). The relationship between intraoperative variables and graft patency was assessed using Cox proportional hazard models.
Highest RITA failure rates were associated with grafting a native coronary artery with a stenosis of less than 60% compared with 80-100% (RR 3. 8 (95% CI, 1.9-7.2) P=0.0001). Grafts to non-LAD arteries had a higher risk of failure, the highest risk ratio being associated with grafting the right coronary artery (RR 4.0 (95% CI, 0.9-17.4) P=0.06)). Free compared with in situ grafts were also associated with a higher risk of failure with this result bordering on statistical significance (RR 1.9 (95% CI, 1.0-6.0) P=0.06))
Preference should be given to grafting arteries with a high grade stenosis or occlusion, to grafting left rather than right coronary arteries, and to using in situ rather than free ITA grafts. Passing the RITA to the left, either anterior to the aorta or through the transverse sinus, did not influence patency.
左乳内动脉（LITA）移植至左前降支动脉（LAD）时，通常被认为是冠状动脉旁路移植术（CABG）的首选血管桥。相比之下，右乳内动脉（RITA）尽管长期用作冠状动脉移植血管，但其作用和疗效相对了解较少。因此，在本研究中，我们通过检查原位和游离RITA移植血管的长期通畅情况，并分析术中移植血管和冠状动脉变量之间的关联，来评估RITA作为冠状动脉血管桥的效用。
本观察性分析纳入了1985年至1998年间接受CABG并因心肌缺血证据接受再次血管造影的962例患者（LITA 962例，RITA 432例）。在初次手术时记录乳内动脉（ITA）的直径、与主动脉近端吻合的情况、与冠状动脉吻合的位置以及冠状动脉直径。随访时间为67.0±39.4个月（平均值±标准差，范围0.1 - 169.5个月）。使用Cox比例风险模型评估术中变量与移植血管通畅性之间的关系。
与狭窄80% - 100%的冠状动脉相比，移植至狭窄小于60%的自身冠状动脉时RITA失败率最高（风险比3.8（95%置信区间，1.9 - 7.2），P = 0.0001）。移植至非LAD动脉的血管桥失败风险更高，最高风险比与移植至右冠状动脉相关（风险比4.0（95%置信区间，0.9 - 17.4），P = 0.06））。与原位移植血管相比，游离移植血管失败风险也更高，此结果接近统计学显著性（风险比1.9（95%置信区间，1.0 - 6.0），P = 0.06））
应优先选择移植至高度狭窄或闭塞的动脉，优先移植至左冠状动脉而非右冠状动脉，优先使用原位而非游离ITA移植血管。将RITA向左绕过主动脉前方或穿过横窦，不影响通畅性。
