经胸多普勒超声心动图观察及评价冠状动脉搭桥术后乳内动脉血管桥及其通畅性的研究

目的:观察冠状动脉旁路移植术(CABG)后乳内动脉及血管桥的血流动力学,评价血管桥通畅性。方法:104例CABG术后患者的所搭血管桥中均包括左乳内动脉(LIMA)与前降支或其远端吻合。以多普勒超声观察LIMA及血管桥血流形态、方向和流速等。以右侧未搭桥乳内动脉(RIMA)或术前同侧LIMA资料作为比较。结果:LIMA血管桥血流以舒张期(D期)为主,流速0.31±0.27m/sec,较术前及RIMA明显增高。收缩期(S期)流速0.31±0.25m/sec,较术前及RIMA明显降低。D/S为1.86±1,较术前及RIMA明显升高。术前LIMA与RIMA血流以S期为主,D期仅见少许血流信号。结论:经胸多普勒超声可以观察CABG前后乳内动脉及血管桥的形态与血流动力学改变。     

经胸超声对乳内动脉桥血管通畅性的评价

冠状动脉旁路移植术（CABG）是目前治疗冠心病的有效方法之一。乳内动脉的高通畅率在临床已得到广泛认可。CABG术后血管桥有无再狭窄的发生以往评价主要依靠血管造影进行判断，但因其属于有创性检查且费用较高，目前在我国多数患者尚不能接受。因此寻求一种可靠、安全、无创的方法对桥血管的通畅性进行评价以判断预后具有非常重要的临床价值。     

CABG术中即时血流监测对桥血管通畅性的评价

目的:应用即时血流监测技术评价CABG术中桥血管通畅性,以便早期发现低血流量并及时给予纠正。方法:1999～2001年,采用即时血流监测仪对69例165根桥血管血流量进行监测,同时纪录体循环血压,观察即时心电图的变化及桥血管远端的病变情况。结果:术中应用乳内动脉60根,平均血流量19.32±17.33ml/min。应用大隐静脉桥共105根,其中对角支22根,平均血流量25.75±20.15ml/min;回旋支43根,平均流量46.56±25.68ml/min;右冠状动脉41支,平均血流量34.08±20.21ml/min。平均搏动指数3.01±1.58。3根(1.8％)桥血管血流量低,血流波形不满意,且搏动指数增高,其中2根为吻合口狭窄,1例为血管扭曲,经重新修正后恢复正常。结论:即时血流监测作为评价桥血管通畅性的一种方法,其技术操作方便、可靠,值得在临床上推广应用。     

经胸超声评价冠状动脉旁路移植术后乳内动脉桥血管通畅性

目的探讨经胸多普勒超声心动图(TDE)在冠状动脉旁路移植术(CABG)后评价桥血管通畅性的应用价值.方法经冠状动脉造影随访证实CABG术后左乳内动脉(LIMA)桥通畅者19例,应用TDE分别探查LIMA桥起始段、胸段、远段、吻合口及远段左前降支,测量各段收缩期峰值流速(SPV)、舒张期峰值流速(DPV)、收缩期速度时间积分(SVTI)、舒张期速度时间积分(DVTI),并计算舒张期与收缩期峰值流速比值(D/S)、舒张期速度时间积分分数(DF).结果LIMA桥起始段及胸段检查均成功18例(18/19),仅有3例患者D/S＜0.6,DF＜0.5;14例能清晰显示吻合口图像,LIMA桥远段、吻合口及远段左前降支血流参数测值比较差异无统计学意义(P＞0.05).与冠状动脉造影结果相比较,TDE多节段探查判断LIMA桥通畅的准确率为95%(18/19).结论采用TDE多节段探测LIMA桥是判断其通畅性的一种可行、可信并无创的方法.     

冠脉搭桥术中包裹乳内动脉血管桥预防再手术粘连

目的：探讨避免仍通畅的乳内动脉血管桥在再次冠脉搭桥术中受到损伤的预防方法。方法：在１０例冠脉搭桥术中应用膨胀聚四氟乙烯外科隔膜包裹乳内动脉预防再手术时的粘连。结果：被包裹的乳内动脉保持通畅功能,未发现有病人发生感染并发症。４年半后其中１例行再次搭桥术,术中见外科隔膜确能起到预防粘连作用。结论：临床结果提示此方法简便易行并能安全有效地保护乳内动脉避免再手术时的损伤。     

冠状动脉血流显像评价冠状动脉搭桥术后胸廓内动脉桥通畅性的研究

目的探讨冠状动脉血流显像技术评价冠状动脉搭桥术后胸廓内动脉桥通畅性的价值。方法对左胸廓内动脉一冠状动脉搭桥术并行桥血管造影术的9例患者进行随访，其中转流至左前降支者8例，转流至对角支者1例。3例因桥血管狭窄或闭塞于造影术中行左前降支近中段支架术。在冠状动脉造影前超声探测胸廓内动脉桥起始段、冠状动脉左前降支远段，分别测量各段收缩期峰值流速、舒张期峰值流速、收缩期流速时间积分、舒张期流速时间积分。评价桥血管通畅性，并与冠状动脉造影结果进行对照分析。行支架术患者于支架术后再行超声检查，观察上述参数变化。结果超声根据桥血管起始段频谱形态诊断桥血管通畅3例，狭窄3例，桥血管功能不良2例，闭塞1例。行支架术的3例患者，2例为吻合口狭窄患者表现为支架术后桥血管舒张期流速降低，其中1例阻力增高；1例胸廓内动脉桥闭塞无改变。3例患者左前降支远段舒张期流速增高。结论常规超声结合冠状动脉血流显像技术是可行、可信、无创性探测桥血管通畅性的方法，可用于冠状动脉搭桥术后的随访。     

冠状动脉旁路移植术中血管桥的保护

冠状动脉旁路移植术（CABG）是在阻塞的冠状动脉远端和升主动脉之间作血管移植，以改善心肌缺血状态。乳内动脉、桡动脉、大隐静脉等是CABG所采用的血管桥材料。血管桥的选择和处理是关系CABG成败的关键因素之一，对血管桥采取积极的抗痉挛策略是提高CABG远期手术效果的重要环节。我院1997年10月-2005年12月行CABG128例，共移植血管桥367根，现报道如下。     

CT血管造影分析体外循环与非体外循环冠状动脉旁路移植后的桥血管通畅率

背景：近年来,非体外循环冠状动脉旁路移植后桥血管通畅率是否与传统的体外循环冠状动脉旁路移植相同存在争议。目的：探讨体外循环与非体外循环冠状动脉旁路移植后桥血管时间通畅率的差异性。方法：选取同一操作者行体外循环冠状动脉旁路移植患者100例,按其临床特征及桥血管病变危险因素匹配抽取非体外循环冠状动脉旁路移植患者137例。采用64排多螺旋CT血管造影分析冠脉搭桥后1个月,1年,2年,3年,4年的桥血管通畅情况。结果与结论：共对641条桥血管进行评价,两组中左侧乳内动脉桥血管时间通畅率均高于大隐静脉桥,两组左侧乳内动脉桥和大隐静脉桥血管时间通畅率比较差异均无显著性意义。说明非体外循环与体外循环冠状动脉旁路移植后患者桥血管时间通畅率相似,对于某些适当的患者来说,非体外循环冠状动脉旁路移植不失为一个良好的选择。     

CT血管造影分析体外循环与非体外循环冠状动脉旁路移植后的桥血管通畅率

背景:近年来,非体外循环冠状动脉旁路移植后桥血管通畅率是否与传统的体外循环冠状动脉旁路移植相同存在争议.目的:探讨体外循环与非体外循环冠状动脉旁路移植后桥血管时间通畅率的差异性.方法:选取同一操作者行体外循环冠状动脉旁路移植患者100例,按其临床特征及桥血管病变危险因素匹配抽取非体外循环冠状动脉旁路移植患者137例.采用64排多螺旋CT血管造影分析冠脉搭桥后1个月,1年,2年,3年,4年的桥血管通畅情况.结果与结论:共对641条桥血管进行评价,两组中左侧乳内动脉桥血管时间通畅率均高于大隐静脉桥,两组左侧乳内动脉桥和人隐静脉桥血管时间通畅率比较差异均无显著性意义.说明非体外循环与体外循环冠状动脉旁路移植后患者桥血管时间通畅率相似,对于某些适当的患者来说,非体外循环冠状动脉旁路移植不失为一个良好的选择.     

冠状动脉旁路移植术中与术后左内乳动脉桥血流对比分析

目的　为评估冠状动脉旁路移植术 (CABG)后患者内乳动脉桥的血流状态探索一种有效、安全及简便的检查方法。方法　对CABG术后 3 6例患者 (据左前降支狭窄程度分为两组 :1组 ,狭窄≥ 90 % ;2组 ,狭窄 <90 % )进行经胸多普勒超声检查 ,测定左内乳动脉 -前降支 (LIMA -LAD)血管桥的各项血流参数并计算出收缩期血流量、舒张期血流量和平均血流量 ,与术中即时超声血流探测仪TTFM (transit-timeflowmeter)直接测量的LIMA -LAD血管桥各期血流量分析比较。结果　①LIMA -LAD血管桥术中经TTFM检测及术后经胸多普勒超声检测 ,其舒张期血流量与舒张期血流量 收缩期血流量比值相关性较好 (r值分别为 0 .67,0 .78) ;②组间舒张期血流量 收缩期血流量比值的差异有显著性(术中P =0 .0 0 0 ;术后P =0 .0 3 8)。结论　①经胸多普勒超声可作为CABG术后检测LIMA -LAD血管桥血流特征的一项有实用价值的检测技术 ;②CABG术前前降支狭窄越重 ,CABG术后LIMA -LAD血管桥的冠状动脉血流特征越明显     

Noninvasive assessment of left and right internal mammary artery graft patency with high-frequency transthoracic echocardiography.

OBJECTIVES: The aim of this study was (1) to visualize internal mammary artery grafts (IMAG) on coronary artery by transthoracic echocardiography and (2) to assess the patency of the grafts. METHODS: Twenty-three patients (21 men, 56 +/- 6 years) with previous coronary artery bypass grafting were studied at baseline and after they underwent low-dose dipyridamole infusion. The parameters obtained were systolic (SPV) and diastolic (DPV) peak velocities and their ratio (DPV/SPV); the dipyridamole infusion to baseline ratio of DPV was an index of IMAG blood flow reserve (FR). Two groups of patients were selected at baseline: group A, (n = 12) with a DPV/SPV >1, and group B (n = 11), with a DPV/SPV <1. RESULTS: The IMAG was identified in all patients. Intraluminal flow signals obtained with pulsed wave Doppler showed a biphasic pattern (1 systolic and 1 diastolic wave). After dipyridamole infusion was administered, flow velocities increased in 11 of 12 patients in group A and in 5 of 11 patients in group B. In group A the DPV/SPV increased from 1.79 +/- 0.47 to 1.8 +/- 0.43 (P = not significant), and the FR was 1.8 +/- 0.4. In group B the DPV/SPV increased from 0. 46 +/- 0.05 to 0.5 +/- 0.09 (P = not significant), and the FR was 1. 3 +/- 0.41. Coronary angiography showed the graft patency in all patients in group A and in 5 patients in group B with increased flow velocity after dipyridamole infusion. In the identification of graft stenosis at baseline, DPV/SPV showed 100% sensibility and 58% specificity, and FR showed 92% sensibility and 84% specificity. CONCLUSION: Doppler echocardiographic evaluation of the IMAG is a simple noninvasive method to assess the functional impairment of the vessel.     

Non-invasive assessment of graft patency using transcutaneous Doppler echocardiography for the validation of functional improvement after PTCA of the LAD via internal thoracic artery graft

Percutaneous transluminal coronary angioplasty (PTCA) of a native coronary artery via internal thoracic artery (ITA) graft after bypass surgery is a relatively rare procedure. Our current study evaluates the flow velocity patterns of the graft before and after PTCA. After intervention the mean diastolic flow velocity increased under rest and stress conditions. In addition, the graft patency was proved not before control angiography after 6 months. It could be verified that the measurement of flow velocity patterns under rest and stress conditions is a useful non-invasive procedure for monitoring long-term patency and PTCA-results of this vessel.     

超声心动图评价经导管冠状动脉瘘封堵治疗疗效

目的 探讨超声心动图评价冠状动脉瘘(coronary artery fistula,CAF)经导管封堵治疗疗效的价值.方法 回顾性分析17例CAF患者封堵术前及术后随访的超声心动图资料,观察CAF受累冠状动脉、瘘口的位置和大小等,经导管封堵术后封堵器的位置形态、有无残余分流、房室大小变化等.结果 术前超声心动图检查17例均为单支冠状动脉病变,瘘口大小2～14 mm,平均(6.4±3.5)mm.17例均封堵成功,术后1～4 d超声心动图检查分流消失.随访观察(11.7±7.9)个月,封堵器位置形态正常,无并发症发生,左心室大小恢复正常.结论 CAF经导管封堵治疗是一种微创、安全、疗效确切的方法 ,超声心动图是术前初步筛选及术后随访的主要方法 .

Abstract：

Objective To investigate the efficacy of transcatheter closure of coronary artery fistula (CAF) by transthoracic echocardiography(TTE) and the role of TTE in this therapy. Methods CAF were occluded with transcatheter closure techniques in 17 patients. TTE was performed before and after the treatments. The key points were retrospectively analyzed including: the sites of CAF, the position and diameter of CAF,the shape and position of the devices after the intervention,the residual shunt,and cardiac chamber size. Results Before the therapy,TTE made definite diagnosis of CAF. All patients had lesions in single coronary artery, and the diameter of CAF was 2-14 (6.4 ± 3.5)mm. All patients underwent transcatheter closure successfully. TTE revealed the shunts disappear 1-4 days after the occlusion. During a follow-up period of 1- 29 (11.7± 7.9)months,no residual shunts, no complications, and normal size of thecardiac chambers were recognized by TTE. Conclusions The transcatheter closure of CAF has emerged as a less invasive, safe and effective strategy. Echocardiography has important role in primary screening of patients and the follow-up after the treatments.     

Demonstration of coronary artery flow using transthoracic Doppler echocardiography.

Transthoracic Doppler echocardiography is emerging as a promising method for evaluating coronary artery disease. After a period of training, detection and measurement of distal left anterior descending coronary artery flow with transthoracic Doppler echocardiography is feasible in more than 90% of the patients. Using transthoracic Doppler echocardiography with a high-frequency transducer and special setting of low Nyquist limits, pathologic coronary flow dynamics can be demonstrated. Measurement of coronary flow reserve may impact diagnosis or clinical treatment in those: (1) with anginal chest pain and angiographically normal coronary arteries; (2) with intermediate-grade coronary obstruction where the physiologic significance is in doubt; and (3) who have had an attempt at revascularization and the effectiveness of the therapy is uncertain.     

经胸超声冠状动脉血流成像预测左前降支狭窄

目的评价经胸超声冠状动脉血流显像技术(TTDE)预测左前降支(LAD)狭窄的准确性.方法 65名临床怀疑为冠心病的患者,在静息状态下用TTDE探测LAD血流,计算舒张期血流速度与收缩期血流速度的比值(DSVR).患者在TTDE检查后24 h内接受冠状动脉造影检查(CAG).结果 53例患者的LAD血流得到探测和测量,其中14例有LAD显著狭窄(≥70%,狭窄组),39例无显著狭窄(对照组).狭窄组LAD的舒张期峰值血流速度和平均血流速度与对照组无显著差异(P＞0.05),但收缩期峰值血流速度和平均血流速度均高于对照组(26.4±11.8 cm/s vs 21.1±6.1 cm/s和18.1±7.8 cm/s vs 14.7±4.0 cm/s,P<0.05).狭窄组的峰值DSVR和平均DSVR较对照组小(分别为1.4±0.4比 2.0±0.5和1.4±0.4比1.9±0.4,P<0.0001).以平均DSVR≤1.6作为异常时,预测LAD狭窄的敏感性和特异性分别为85.7%和79.5%.结论用TTDE测定DSVR是一种简便无创的预测LAD狭窄的新方法.     

Long-term internal thoracic artery bypass graft patency and geometry assessed by multidetector computed tomography

The left internal thoracic artery (LITA) undergoes vascular remodelling when used for coronary artery bypass grafting. In this study we tested the hypothesis that the extent of the LITA remodelling late after coronary artery bypass grafting assessed by multidetector computed tomography is related to the severity of stenosis in the native coronary vessel. One hundred and forty-two patients who had undergone coronary artery bypass grafting including implantation of LITA as conduit to the left anterior descending artery were studied 5 years after surgery. Arterial graft patency and geometry was assessed with 64-slice multidetector computed tomography. Quantitative volumetric assessment of the LITA was performed to measure the average vessel lumen area (mm²/m²). The native coronary vessel subtended by the LITA was evaluated by multidetector computed tomography and defined as a high-grade stenosis patient group, when the diameter stenosis was >70% and an intermediate grade stenosis patient group when <70%. Among patients with intermediate-grade stenosis of the native vessel 11 out of 65 patients (17%) had a totally occluded LITA, as opposed to none among the 77 patients with a high-grade stenosis. In patients with intermediate-grade stenosis of the proximal native vessel, the LITA lumen area was 4.9 compared to 5.3 mm²/m² in patients with a high-grade stenosis of the proximal native vessel (P = 0.0043). Lumen area of the LITA when used as a conduit in patients with coronary artery disease seems to be inversely correlated with the severity of disease in the native coronary vessel proximal to the anastomosis. Volumetric vessel multidetector computed tomography appears to be useful for evaluation of coronary bypass remodelling.     

Assessment of coronary artery bypass graft patency by multidetector computed tomography and electron-beam tomography

This case report describes the use of retrospectively ECG-gated 16-slice multidetector computed tomography (MDCT) and electron-beam tomography (EBT) for assessing bypass graft patency in two patients with recurrent angina after coronary artery bypass graft surgery. The results of each tomographic modality were compared to the findings of traditional coronary angiography. In the first patient MDCT showed occlusion of the left internal mammary artery (LIMA) and saphenous vein graft after the second anastomosis. Coronary angiography confirmed these findings. In the second patient EBT showed patency of the LIMA and saphenous vein graft. After the first anastomosis of the saphenous vein graft, the connected vessel filled poorly. Coronary angiography confirmed both grafts to be patent, and detected an occlusion distal to the first anastomosis. These findings support the evidence that both MDCT and EBT are suitable techniques for establishing bypass graft patency by non-invasive means.     

Nonangiographic assessment of coronary artery bypass graft patency

Coronary artery bypass graft patency can be assessed using the indirect techniques of evaluating patients' symptoms and exercise tolerance, changes in stress electrocardiogram, radioisotope regional perfusion, and myocardial wall contraction. The direct techniques assess graft patency directly by visualizing grafts using conventional computed tomography (CT), ultrafast CT, magnetic resonance imaging, digital subtraction angiography, and echocardiography. The advantages and disadvantages of each of these modalities are reviewed. At the present time, ultrafast CT and possibly magnetic resonance imaging and Doppler appear to be the only techniques besides angiography that can consistently evaluate bypass graft patency. Although they have the advantage of being minimally invasive, they cannot show graft stenosis or sequential graft patency. These techniques are best used in following patients after coronary bypass graft surgery and ruling out graft closure as the source of chest pain.