主动脉隔离技术应用于非体外冠脉手术中期疗效评估

目的：总结主动脉隔离技术用于非体外循环冠状动脉旁路移植手术的经验，探讨其可行性与安全性，评估中期临床疗效。方法：在180例非体外循环下冠状动脉旁路移植手术中，应用Enclose装置，以主动脉隔离技术完成桥血管与升主动脉近端吻合。术前用薄层CT平扫评价升主动脉粥样硬化及钙化程度，术中用超声检查升主动脉结合手指扪查升主动脉。23例（12.8%）存在明显升主动脉粥样硬化斑块或钙化灶。术中再血管化的顺序为：（1）应用主动脉隔离技术，完成所有静脉或桡动脉桥血管与主动脉近端吻合；（2）左乳内动脉与左前降支远端吻合；（3）顺次完成所有桥血管与冠状动脉远端吻合。术后常规应用肠溶阿司匹林及硫酸氢氯吡格雷抗血小板治疗。结果：共完成桥血管536根，平均2.98±0.8根·例^-1。用主动脉隔离技术成功完成近端吻合口408个；其中，桡动脉桥近端吻合口7个，静脉桥近端吻合口401个，平均2.27±0.7个·例^-1。术中无技术故障和相关意外情况发生。围手术期死亡4例（2.2%）。176例存活患者无心肌梗死、脑梗死、主动脉夹层动脉瘤、二次开胸止血及心功能衰竭等严重围术期并发症和心脏相关事件发生。术后147例（83.5%）存活患者接受门诊或电话随访，随访时间27.7±9.4（6～39）个月。1例（0.7%）患者术后15个月死于肠道肿瘤；胸痛发生率2.7%、房颤发生率2.0%、脑梗发生率3.4%、下肢栓塞发生率1.4%。全组患者无其它心血管不良事件发生。术后心功能NYHA分级较手术前明显改善（P〈0.05）。术后30个月以上的25例患者行冠状动脉CTA检查，结果58个桥血管近端吻合口中53个（91.4%）近端吻合口均通畅。结论：用Enclose装置的主动动脉隔离技术可安全地用于非体外冠脉旁路移植术的近端吻合，尤其可用于升主动脉明显钙化和粥样硬化的患者，术后中期疗效满意。     

在OPCAB术中应用Enclose Ⅱ近端吻合装置的护理配合

目的探讨在非体外循环冠状动脉搭桥术(Off-pump coronary artery bypass,OPCAB)中应用EncloseⅡ主动脉近端吻合装置的手术配合方法。方法回顾分析2013年6月—2014年12月我院对9例合并升主动脉钙化的冠心病患者施行的OPCAB术,术中在行静脉桥与升主动脉近端吻合时采用EncloseⅡ主动脉近端吻合装置;总结其护理配合方法,术后观察患者神经系统并发症的发生情况。结果 9例手术均顺利完成,无围术期死亡病例,无1例吻合口漏血,术后患者顺利清醒,无神经系统并发症发生。结论对合并升主动脉钙化的冠心病患者,在OPCAB术中应用EncloseⅡ主动脉近端吻合装置,予正确有效的护理配合,可有效地减少术后神经系统并发症的发生。     

47例非体外循环心脏跳动下冠状动脉旁路移植术治疗体会

目的：总结47例非体外循环心脏跳动下冠状动脉旁路移植术（OPCAB）的临床经验。方法：对2002年12月~2006年12月进行非体外循环心脏跳动下冠状动脉旁路移植术的47例病人进行临床分析。全组男41例，女6例，平均年龄（53．12±8．31）岁；其中陈旧性心肌梗死19例，急性心肌梗死5例，不稳定性心绞痛36例，合并高血压23例，糖尿病15例，慢阻肺5例。左心室射血分数平均0．48土0．32。结果：全组共行左乳内动脉桥吻合47支，桡动脉桥4支，大隐静脉桥59支。2例术中改为体外循环下行冠状动脉搭桥术（CCABG）。应用主动脉内球囊反搏（IABP）6例。死亡1例，46例10～18d痊愈出院。结论：OPCAB与传统的体外循环下冠状动脉搭桥术（CCABG）相比，有一定的优势。体外循环准备是OPCAB手术不可缺少的一部分。合理使用主动脉内球囊反搏有助于提高OPCAB手术的成功率，降低术后死亡率。     

桡动脉与大隐静脉"V"形组合血管桥在冠状动脉旁路移植术中的应用

目的探讨冠状动脉旁路移植手术(CABG)中升主动脉近端血管的"V"形桡动脉与大隐静脉组合血管桥("V"形桥)的吻合方法及近期临床效果。方法回顾性选择2015年4月至2018年10月在首都医科大学附属北京友谊医院行单纯非体外循环下不停跳CABG手术的21例患者,行升主动脉近端吻合时用大隐静脉或桡动脉与主动脉根部做近端端侧吻合,作为血源桥。另外一根血管桥的近端与血源桥近端(0.5 cm内)做端侧吻合,形成"V"形吻合。术后30天观察患者死亡率。术后3～6个月,通过冠状动脉CTA检查评价"V"形桥吻合口以及远端吻合口的近期通畅性。结果 21例患者中,术后30 d死亡率为0(0/21)。术后3～6个月,除1例"V"形桥吻合口桡动脉分支闭塞外,其余病例吻合口均通畅,"V"形桥吻合口及远端吻合口的通畅率均为95.2%(20/21)。结论应用"V"形桥行CABG的升主动脉近端吻合是一种安全有效的新术式,临床效果满意,近期通畅率高。     

近端升主动脉CT三维重建在胸骨下段小切口非体外循环下多支冠状动脉旁路移植的临床应用

目的使用近端升主动脉CT三维重建参数评估胸骨下段小切口完成非体外循环心脏不停跳下冠状动脉旁路移植(MIST-OPCAB)的近端吻合空间,完成多支病变的完全再血管化。方法对2015年1月至2017年5月首都医科大学附属北京友谊医院收治的行MIST-OPCAB的250例手术患者进行回顾性研究,使用术前胸部正侧位X线片和近端升主动脉CT三维重建的相关测量参数以及术前超声心动图、冠状动脉造影结果进行术前评估,选择适合行胸骨下段小切口的冠状动脉旁路移植患者。研究对象分组:(1)小切口组(即A组),112例MIST-OPCAB手术患者;(2)常规切口组,138例常规切口OPCAB患者。常规切口组再分为B组(CT参数适合行小切口手术,其它条件不适合行小切口手术)和C组(CT参数不适合行小切口手术)。比较三组患者升主动脉CT三维重建参数,观察桥血管分布及手术结果。结果小切口组112例,常规切口组138例,小切口组的左室射血分数(LVEF)大于常规切口组(66. 1±5. 5%vs. 63. 9±5. 8%,P 0. 05)。A组第2肋间胸骨平面至主动脉根部的距离明显大于C组[(32. 6±15. 8) mm和(26. 9±16. 5)mm,P 0. 05];小切口组112例患者均顺利完成手术,旁路移植2～4支,平均(2. 8±0. 6)支;近端1个吻合口108例,2个吻合口4例。远端靶血管分别吻合至前降支(LAD) 112例、后降支(PDA) 91例、钝缘支(OM) 56例及中间支(IR) 20例,对角支(Dx) 35例。使用左侧乳内动脉(LIMA) 111例,桡动脉(RA) 89例,大隐静脉(SVG) 105例。术后呼吸机辅助时间平均[19±22,(5,85)]h,重症监护室时间[60±20,(12,145)]h。结论升主动脉近端CT三维重建参数能够准确评估胸骨下段小切口完成非体外循环心脏不停跳下冠状动脉旁路移植,且远端靶血管血运重建临床效果满意。MIST与传统全程胸骨切口相比的优点是保存了部分胸廓完整性。     

非体外循环与常规体外循环下冠状动脉旁路术的早期结果分析

目的 分析非体外循环下冠状动脉旁路移植术（OPCAB）与常规体外循环下冠状动脉旁路移植术（CCABG）的早期结果，评价上述两种方法的手术效果。方法回顾分析本院自1999年1月～2003年4月收治的223例确诊为多支血管病变行冠状动脉移植术的冠心病患者，按手术方法分为OPAB组与CCABG组；两组病例中均不包括同期行瓣膜置换术及室壁瘤切除术等合并手术者；OPCAB组在非体外循环，心脏跳动下完成手术，CCABG组在常规体外循环，心脏停跳下完成手术；将两组患者的术前及术后临床资料进行分析。结果两组患者术前一般资料经统计学分析均无明显差异，移植桥血管数亦基本相同，OPCAB组在术后呼吸机辅助时间、胸液引流量、输血量、术后并发症及平均住院日方面均优于CCABG组。结论OPCAB方法可应用于多支病变的冠心病患者的外科治疗，与CCABG方法相比，可减少术后早期并发症的发生，缩短患者的住院时间，但应严格掌握手术适应证，其远期疗效有待进一步跟踪随访。     

Symmetry近端吻合器的实验研究

目的:利用Symmetry近端吻合器进行静脉移植物与升主动脉吻合的动物实验,评价其吻合时间、吻合口血流量和通畅率,为临床应用提供科学依据。方法:以犬作为实验对象,取自体股静脉作为移植血管,在非体外循环心脏不停跳下完成主动脉至右冠状动脉的冠状动脉旁路手术(OPCABG)。以Symmetry近端吻合器完成的近端吻合口作为实验组(N=9),以5-0.Prolene缝线手工缝合的近端吻合口作为对照组(N=5)。测量、比较两组的吻合时间。术中应用多谱勒血流量仪测量吻合口的血流量。静脉内注射新福林提高血压,观察不同压力下吻合口的渗漏。结果:实验组吻合时间为101.33±10.46s,对照组为208.20±22.61s,P<0.01。实验吻合口的血流量平均为11.48±0.88ml/min,对照组为11.84±0.59ml/min,P>0.05。实验组所能承受的最大血压平均为182.7±4.7mm-Hg,明显高于对照组171.0±8.9mmHg,P<0.01。结论:Symmetry近端吻合器是一种简易、有效、快速和可靠的冠状动脉近端吻合装置。可避免钳夹主动脉,减少神经系统并发症,并在微创冠状动脉搭桥术中有较高的应用价值。     

主动脉隔离装置在非体外循环下冠状动脉旁路移植术中应用的护理配合

非体外循环下冠状动脉旁路移植术(OPCAB)是目前治疗冠心病的主要外科手段.它避免了常规心脏手术带来的体外循环损伤和心脏缺血再灌注损伤,降低了手术死亡率,尤其适合老年病人、低射血分数病人、合并重要脏器功能损伤的病人和其他重症冠心病病人.虽然其技术成熟且疗效显著,但其术后高达14%的神经系统并发症发生率仍然影响着远期预后.其原因与升主动脉硬化斑块松动或脱落相关[1].OPCAB传统术式的近端吻合口采用大隐静脉或桡动脉与升主动脉进行吻合,缝合时需用侧壁钳钳夹部分升主动脉,因此可能引起钳夹部位动脉硬化斑块脱落,增加全身栓塞尤其脑栓塞的发生率,同时还可能引起大隐静脉桥阻塞导致围术期心肌梗死[2].     

151例非体外循环冠状动脉旁路移植术围术期处理体会

目的：总结非体外循环下冠状动脉旁路移植术（OPCAB）的临床应用经验。方法：对151例非体外循环冠状动脉旁路移植术患者的临床资料、手术情况及术后并发症情况进行总结、分析。结果：1．51例患者均在非体外循环心脏跳动下完成手术，人均旁路移植3．28根；术后出现低心排4例，低氧血症18例，胸骨哆开3例，快速房颤15例，经治疗后均治愈，无围术期死亡，疗效满意。结论：严格掌握手术适应证，熟练的外科手术技巧，妥善细致的围术期处理，及时发现和处理术后并发症，是提高OPCAB成功率的关键。     

非体外循环冠状动脉旁路移植术初探

目的:报告非体外循环冠状动脉旁路移植术的临床应用和初步体会。方法:22例冠心病患者(男18例,女4例,年龄49~74岁。平均62·7岁)。均在全麻常温下经胸骨正中切口行OPCAB术,人均远端吻合口3·0±0·9个。结果:全组1例死亡,其余恢复顺利,疗效满意。术后平均呼吸机辅助时间1194·7分钟,人均输血788·2ml,术后患者心绞痛症状均消失,心功能改善。结论:OPCAB安全、有效,是一种值得推广的治疗冠心病的微创手术方法。     

升主动脉No—touch技术在冠心病手术中的应用

目的探讨和评价升主动脉不接触技术（No—touch）在冠状动脉旁路移植手术中的应用。方法回顾5例合并升主动脉粥样硬化冠心病患者的临床资料,男3例,女2例,年龄68--76岁,平均70．2岁。5例均采用常规胸骨正中切口行非体外循环下冠脉搭桥（OPCABG）。2例行双侧乳内动脉原位移植,3例以左乳内动脉为唯一的供血来源,大隐静脉近端与左乳内动脉端侧吻合。所有患者未在升主动脉上进行任何操作。结果5例患者共移植血管13支,全组手术均顺利完成,痊愈出院,无院内死亡。手术后所有忠者心绞痛均消失,心功能改善I～II级。无围术期心肌梗死和神经系统并发症发生。结论对合并升主动脉粥样硬化的冠心病患者,采用OPCABG结合升主动脉不接触（No—touch）技术,可使病变冠脉完全再血管化,降低术后脑卒中的发生率,临床效果满意。     

Endovascular repair of the aortic arch

The aortic arch is a challenging site for endovascular repair. The proximal implantation site is often wide, angulated, conical, and limited in length by the presence of vital branches to the head and arms. The only way to lengthen the implantation site without risking stroke is to provide an alternative source of inflow through endovascular or extravascular bypass. The complexity and stroke risk of branched stent-graft implantation increases exponentially with each additional branch. In our opinion, the safest strategy is to limit the stent graft to a single side branch. This bifurcated stent graft requires multiple bypass grafts in the neck but avoids median sternotomy and partial aortic clamping. Stent-graft implantation through the carotid or innominate artery provides a short, straight route to the proximal ascending aorta and ensures simple accurate placement of the innominate limb. In our experience, the primary limitation has been the anatomy of the ascending thoracic aorta, which may be too short or too wide. Previously created coronary bypass grafts (if patent) may also prevent proximal stent-graft implantation. The bypass grafts and route of access through the neck and groin are created using standard surgical techniques. Both components of the stent graft are implanted during brief periods of cardiac standstill. The tip of the bifurcated stent-graft delivery system is introduced over a curved guidewire into the left ventricle. Otherwise, the endovascular techniques of bifurcated arch repair are essentially those of bifurcated abdominal aortic repair. Despite high flows and wide-diameter components, current experience has shown bifurcated stent grafts of this type to be stable with follow-up over 3 years.     

升主动脉No-touch技术在冠心病手术中的应用

目的探讨和评价升主动脉不接触技术(No-touch)在冠状动脉旁路移植手术中的应用。方法回顾5例合并升主动脉粥样硬化冠心病患者的临床资料,男3例,女2例,年龄68~76岁,平均70.2岁。5例均采用常规胸骨正中切口行非体外循环下冠脉搭桥(OPCABG)。2例行双侧乳内动脉原位移植,3例以左乳内动脉为唯一的供血来源,大隐静脉近端与左乳内动脉端侧吻合。所有患者未在升主动脉上进行任何操作。结果 5例患者共移植血管13支,全组手术均顺利完成,痊愈出院,无院内死亡。手术后所有患者心绞痛均消失,心功能改善Ⅰ~Ⅱ级。无围术期心肌梗死和神经系统并发症发生。结论对合并升主动脉粥样硬化的冠心病患者,采用OPCABG结合升主动脉不接触(No-touch)技术,可使病变冠脉完全再血管化,降低术后脑卒中的发生率,临床效果满意。     

Comparison of simultaneous antegrade/vein graft cardioplegia with antegrade cardioplegia for myocardial protection

Antegrade cardioplegic delivery via the aorta ensures distribution of cardioplegic solution through open arteries, but distribution may not be adequate beyond a stenotic coronary artery. This potential problem can be overcome by direct delivery of cardioplegia via a vein graft. The purpose of this study was to compare simultaneous antegrade/vein graft cardioplegia with antegrade cardioplegia during coronary artery bypass surgery. Twenty patients were divided into 2 groups. In group 1, intermittent antegrade cardioplegia was provided (n=10). In group 2, intermittent antegrade cardioplegia was supplemented by antegrade perfusion of vein grafts after distal anastomoses were completed (n=10). Data on enzyme release and hemodynamics were obtained preoperatively, before the induction of anesthesia, just before cross-clamping, immediately after aortic unclamping, and at 1, 6, 12, 24, and 48 h after unclamping. Enzyme release (creatinine phosphokinase-isoenzyme MB, cardiac troponin I, myoglobin) was similar in both groups (P > .05). Furthermore, no significant difference was noted in the incidence of postoperative low cardiac output syndrome, perioperative myocardial infarction, or ventricular arrhythmia (P > .05). In conclusion, both techniques permitted rapid postoperative recovery of myocardial function. Supplementation of antegrade perfusion of vein grafts with antegrade cold blood cardioplegia offered no advantage to study patients. However, hemostasis of a distal anastomosis may be controlled by this technique.     

Intraoperative assessment of coronary grafts by novel digital epivascular imaging.

OBJECTIVE: We sought to validate and evaluate 2 novel intraoperative ultrasound probes for epicoronary and epiaortic imaging. BACKGROUND: The noninvasive intraoperative assessment of successful coronary artery bypass grafting remains a challenge. METHODS: A total of 19 consecutive patients (4 female, 15 male; mean age 60.5 +/- 13.8 years SD, range 34-84) underwent coronary artery bypass grafting. The epivascular probes (GE Ultrasound) were validated in vitro and intraoperatively. Coronary arteries, grafts, and ascending aorta were imaged and quantified. RESULTS: Mean adjusted flow measured by flowmeter was 3.25 L, SE 0.47 (range: 1-5.5 L) and was 3.15 L, SE 0.46 (range: 1-5.0 L) by ultrasound, with r = 0.97, P <.0001. Intraoperatively, 56 native coronary vessels were bypassed using 15 left internal mammary artery grafts, 25 vein grafts, and 16 venous jump grafts. A total of 15 left internal mammary artery grafts (100%), 12 left internal mammary artery anastomoses (80%), 20 vein grafts (15 left anterior descending coronary arteries, left circumflex artery grafts, 5 right coronary artery grafts) (80%), 4 jump grafts (25%), and 15 ascending aortas (78%) were successfully imaged by inexperienced surgeons. Doppler flow measurements were possible in 50 vessels (89%). Mean lumen diameter for graft arteries (veins) was 2 mm (2.87 mm), maximal velocity was 72 cm/s (46 cm/s), and mean velocity was 29 cm/s (21 cm/s) with a mean flow rate of 70 mL/m (55 mL/m). CONCLUSIONS: We conclude that: (1) the novel intraoperative probes measure validated flow; (2) intraoperative hemodynamic assessment of graft patency is feasible without a learning curve; and (3) these findings should encourage the routine use of these intraoperative epivascular digital ultrasound probes.     

心脏镜多支冠状动脉搭桥术的动物实验研究

目的探讨心脏镜即不需辅助小切口的完全内镜下多支冠状动脉搭桥术术式的可行性。方法实验动物为2头猪和24条狗,胸壁打孔,进行多支冠状动脉搭桥手术的操作。结果经过1.5cm的3、4个小孔可以完成右冠状动脉、左冠状动脉、前降支、对角支及回旋支等多支冠状动脉的搭桥手术,并能顺利完成左锁骨下动脉、降主动脉的远端吻合口的吻合操作。结论心脏镜多支冠状动脉搭桥术切实可行,值得进一步研究。不久的将来有可能成为心脏搭桥术的主要术式。     

胸主动脉瘤的外科治疗

目的:总结7例胸主动脉瘤病人的外科治疗经验.方法:7例病人中胸降主动脉瘤2例,主动脉根部瘤(马凡综合征)2例,夹层动脉瘤3例,均为Ⅱ型夹层动脉瘤,其中1例合并冠心痛,前降支单支病变.胸降主动脉瘤在低温体外循环下行人工血管置换术.升主动脉瘤和Ⅱ型夹层动脉瘤在低温体外循环下行Bentall手术,其中1例采用带管道无支架生物瓣,同时行冠脉搭桥手术.结果:6例存活,1例死于低心排综合征.结论:在胸主动脉瘤的外科治疗中,Bentall手术是治疗升主动脉瘤较好的手术方法.外科手术技术是手术成功的重要因素.体外循环管理,良好的心肌保护和血液保护是保证手术成功的重要手段.带管道无支架生物瓣对老年人及抗凝有禁忌或主动脉根部较小者更适宜,对合并冠心病的患者宜同期行冠脉搭桥术.     

The modified Bentall procedure for aortic root replacement

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THE BENTALL PROCEDURE is a surgical repair of an ascending aortic or aortic root aneurysm in combination with aortic valve disease. Less commonly, it is used to repair aortic dissection affecting the aortic root and valve.

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DURING THE PROCEDURE, a composite aortic valve graft is used to replace the proximal ascending aorta and aortic valve.The procedure is performed through a median sternotomy during cardiopulmonary bypass.

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IN THIS MODIFICATION of the original procedure, coronary artery circulation is maintained by removing a full-thickness “button” of aorta surrounding the coronary ostia, making it easier to implant the proximal end of the coronary arteries into openings made in the aortic vascular graft.AORN J 84 (July 2006) 52-70.

     

Spontaneous retrograde dissection of ascending aorta from descending thoracic aorta--a case review

A 56-year-old man with sudden onset chest pain, absent right lower limb pulses and ECG changes suggestive of inferior ST elevation MI underwent coronary angiogram through the right radial artery with a view to primary percutaneous coronary intervention (PCI). The left coronary angiogram demonstrated severe proximal stenotic disease in the left anterior descending and circumflex coronary arteries, but the right coronary artery could not be selectively cannulated. An ascending aortogram to visualise the right coronary artery not only failed to demonstrate it, but revealed, instead, a dissection flap in the ascending aorta, arch and descending thoracic aorta, with moderately severe aortic regurgitation. At operation, the patient was found to have an acute dissection of the ascending aorta, arch and descending aorta with an entry tear in the descending aorta below the left subclavian artery origin. Triple coronary artery bypass grafting with re-suspension of the aortic valve, supracoronary replacement of the ascending aorta and hemiarch and transaortic repair of the descending aortic tear was performed. The patient made an uncomplicated recovery, with the re-appearance of right limb pulses. A postoperative magnetic resonance (MR) scan revealed complete thrombosis of the false channel in the residual arch and a considerably shrunken false channel in the descending aorta and no aortic regurgitation. Retrograde dissection of the ascending aorta from the descending aorta has been reported infrequently in the past. We believe the scale of the problem has been underestimated because of the failure to adopt open distal anastomosis routinely in the past and, hence, failure to inspect the arch and the descending aorta routinely, particularly when the intimal tear was not identified in the ascending aorta. Retrograde dissection of the ascending aorta from an intimal tear in the descending aorta, when identified as such, has been managed, either on the principle of exclusion of the tear in the descending aorta by various elephant trunk procedures and their variants or, alternatively, on the principle of excision of the tear by extended one-stage aortic replacement, usually combined with an elephant trunk procedure. Neither of these procedures is widely adopted, owing to procedural, institutional and outcome considerations. We describe a transaortic repair of the intimal tear in the descending aorta with supracoronary interposition graft replacement of the ascending aorta and hemiarch with excellent clinical and radiological result. We also review the diagnostic and therapeutic approaches to this incompletely understood lethal disease.     

New insights into the pathophysiology of coronary arteries by epicardial high frequency echocardiography

Currently, the coronary angiogram remains the "gold standard" for the detection and quantification of coronary arterial disease. Clinical assessment of the arteriogram is usually based simply on the relative percent narrowing of the column of angiographic dye. However, such analysis oversimplifies and is not accurate for evaluating the extent and severity of coronary artery atherosclerosis. Recently a new generation of ultrasonic devices has become available for intraoperative evaluation of coronary arterial anatomy. These high frequency echocardiographic transducers use 12 MHz probes. The transducer is placed directly over the epicardium during open heart surgery to evaluate the coronary artery. With this technique, demonstration of coronary artery anatomy, including wall and cross-sectional lumen, is available in vivo. We have undertaken numerous validation studies in vitro and in vivo of animal and postmortem human heart preparations to show that this technique can be used to accurately measure luminal area, luminal diameter, and wall thickness. Subsequently in patients intraoperatively the extent of atherosclerosis using luminal diameter to wall thickness (LD/WT) ratios was compared with the routine angiographic evaluation of coronary arterial disease using percent stenosis measurements. LD/WT ratios from arterial segments with no visible angiographic disease but with angiographic lesions elsewhere in the same coronary artery showed marked variability. The majority were in the range of LD/WT ratios of those segments where high frequency echocardiography recording was made at the site of "angiographic" disease. This indicates that in vivo atherosclerosis is more widespread than the angiogram predicts and underlies the difficulties of using percent stenosis angiographically to determine the extent and severity of coronary arterial disease. In a second study we have demonstrated that there is marked variability and eccentricity in coronary plaque geometry, luminal morphology, and placement of the residual lumen with respect to the atherosclerotic plaque. This eccentricity results in some relatively "normal" coronary wall at the site of maximum atherosclerosis, theoretically preserving the ability to vasodilate and vasoconstrict. Studies with high frequency echocardiography are underway to study the capability of arteries with atherosclerosis to vasodilate. We have evaluated atherosclerotic remodeling of coronary arteries and found that remodeling occurs in an attempt by the artery to preserve its residual luminal size during encroachment on the lumen by the atherosclerotic plaque. This is the first in vivo demonstration of this process in human coronary arteries. Coronary arterial bypass grafts have been evaluated in animal models and at the time of intraoperative coronary anastomoses to evaluate the adequacy of graft anastomoses and compare vein grafts with internal mammary grafts.(ABSTRACT TRUNCATED AT 400 WORDS)