冠状动脉旁路移植术序贯和单一静脉桥通畅率荟萃分析

目的:比较冠状动脉旁路移植术(CABG)后序贯和单一大隐静脉桥通畅率。方法:检索PUBMED、EMBASE、The Cochrane Library及中国生物医学文献数据库。文献纳入标准:两组患者分别行序贯和单一大隐静脉CABG术;前瞻性或回顾性队列研究,须满足非随机研究方法组制定的队列研究特征;运用冠状动脉造影或超高速CT检查旁路移植术至少1个月以后桥血管通畅情况。文献纳入、数据提取和文献质量评定均由两名研究者独立完成。运用Rev Man5.0和Stata10.0软件进行数据处理,合并相对危险度(RR)作为分析统计量,95%可信区间(CI)为判断结果标准。结果:12篇文献纳入本研究。序贯桥梗阻风险低于单一桥(13.56%vs.19.18%,RR=0.67,95%CI:0.60~0.74);序贯桥中侧侧吻合梗阻风险低于端侧吻合(9.58%vs.14.07%,RR=0.52,95%CI:0.34~0.80);序贯桥和单一桥中端侧吻合梗阻风险,差异无统计学意义(14.07%vs.13.61%,RR=0.85,95%CI:0.68~1.06)。结论:CABG后大隐静脉序贯桥中长期通畅率优于单一桥,序贯桥中侧侧吻合口通畅率优于端侧吻合口,序贯桥和单一桥端侧吻合口通畅率无差别。     

大隐静脉序贯桥行冠状动脉螺旋CT的中期随访结果

目的：评价冠状动脉旁路移植术中应用大隐静脉序贯桥的中期临床效果。方法: 对37例冠状动脉粥样硬化性心脏病患者以大隐静脉序贯桥行冠状动脉旁路移植术,其中男25例,女12例,年龄45-69岁,不稳定性心绞痛患者23例,陈旧性心肌梗塞患者10例,急性心肌梗塞患者4例,于术后2年行冠状动脉螺旋CT随访。结果：37例病人中,35例全部血管桥均通畅,有2例病人乳内动脉桥路通畅,大隐静脉血管桥闭塞,未予介入或手术干预。结论:大隐静脉序贯桥中期随访通畅率良好,虽有“一闭俱闭”的风险,但大多数不会导致心肌梗死。     

桡动脉-大隐静脉组合V形桥在冠状动脉旁路移植术中的应用

目的:对桡动脉-大隐静脉组合V形桥新术式的安全性和近期移植血管通畅率进行初步探讨。方法:选自2015年4月至2016年3月,我院共完成29例桡动脉-大隐静脉组合V形桥冠状动脉旁路移植(CABG)术。平均年龄(65. 3±8. 2)岁,女性4例(16%)。将大隐静脉与升主动脉做近端吻合,桡动脉与该大隐静脉端侧吻合,吻合口距升主动脉的距离≤0. 5 cm。对术后30 d死亡率,桡动脉-大隐静脉组合V形桥吻合口以及远端吻合口的近期通畅性(术后6个月)进行影像学评价。结果:术后30 d死亡率为零;术后6个月对桡动脉-大隐静脉组合V形桥吻合口及远端吻合口的通畅性应用冠状动脉CTA进行评价,通畅率均为100%。结论:桡动脉-大隐静脉组合V形桥CABG术是一种安全有效的新术式,临床效果满意,近期通畅率高。     

复合桥血管在冠状动脉病变合并升主动脉严重钙化小切口冠状动脉旁路移植术中的应用及对中期通畅率的影响

目的探讨Y型复合桥血管(左胸廓内动脉-桡动脉、左胸廓内动脉-大隐静脉)在左前外侧小切口冠状动脉旁路移植术(MIDCAB)中的应用以及术后中期通畅率。方法回顾性分析2013年1月至2015年5月38例冠状动脉病变合并升主动脉严重钙化患者应用Y型复合桥血管的MIDCAB临床资料。男29例、女9例,年龄56~83〔平均(67.8±8.2)〕岁,通过冠状动脉血管造影(CTA)评估术后1年桥血管通畅率。结果全例均顺利完成MIDCAB,无术中转正中开胸,平均手术时间为(3.6±1.1)h,24例采用左胸廓内动脉-桡动脉Y型复合桥血管,14例采用左胸廓内动脉-大隐静脉Y型复合桥血管,平均吻合移植血管(2.7±0.5)支。无围术期二次开胸止血、无术后脑卒中发生以及围术期心梗发生,围术期新发心房颤动3例,经对症治疗恢复窦性心律;肾衰竭1例,经血液透析治愈;ICU入住时间(52.8±19.2)h,全组无住院死亡。术后1年通过冠状动脉CTA随访显示,桥血管的总通畅率为97.1%,其中全部患者左胸廓内动脉-左前降支吻合口通畅率为100%,左胸廓内动脉-桡动脉组出现桡动脉桥血管线征1例,左胸廓内动脉-大隐静脉桥血管阻塞1例,累积桥血管通畅率:左胸廓内动脉-桡动脉桥血管与靶血管吻合通畅率为95.8%,左胸廓内动脉-大隐静脉与靶血管吻合通畅率为92.8%(P>0.05)。结论对于冠心病合并升主动脉严重钙化患者而言,MIDCAB术中采用Y型复合桥血管安全、有效,中期通畅率良好。全动脉桥血管(左胸廓内动脉-桡动脉)是最佳方案,但对于桡动脉无法使用或获取后可能发生手部缺血等并发症的患者,左胸廓内动脉-大隐静脉复合桥血管仍是一种良好的选择。     

冠状动脉旁路移植术后移植血管的转归及影响因素分析

目的:探讨冠状动脉旁路移植术(CABG)后移植血管包括大隐静脉桥(SVG)和左乳内动脉桥(LIMAG)的转归及相关的影响因素。方法:对自2010年至2015年92例行CABG后症状复发而复查冠状动脉(冠脉)自体血管造影和移植血管造影的结果和临床特征进行分析。92例患者中男性83例,女性9例,平均年龄(62.6±10.8)岁。52支LIMAG中,19支发生病变为LIMAG病变组,33支未发生病变为LIMAG无病变组;60支大隐静脉单独桥中,38支有病变的大隐静脉单独桥为大隐静脉单独桥病变组,22支无病变的大隐静脉单独桥为大隐静脉单独桥无病变组。统计分析SVG、LIMAG病变与传统动脉粥样硬化危险因素如年龄、性别、高血压、高脂血症、糖尿病、吸烟、冠心病家族史以及其他临床特点如心绞痛复发时间、冠脉造影距离CABG时间等、大隐静脉桥血管移植方式(序贯桥和单独桥)、自身靶血管搭桥前病变特点的相关性。结果:平均症状复发时间(35.10±24.7)个月。共有移植血管146支,其中LIMAG 52支,SVG 94支(单独桥60支,序贯桥34支),LIMAG通畅率显著高于SVG(63.5%vs 44.7%,P=0.030)。SVG病变发生与CABG后症状复发时间呈正相关(OR=1.119,95%CI:1.002~1.249,P=0.046),与女性患者有相关倾向(P=0.065),与其他临床因素均不相关,而LIMA病变发生与各项临床因素均不相关。大隐静脉序贯桥通畅率明显高于单独桥(58.9%vs 36.7%,P=0.038)。大隐静脉单独桥病变组(术前自体靶血管完全闭塞/狭窄=24支/14支)与无病变组(术前自体靶血管完全闭塞/狭窄者=17支/5支)的自体靶血管病变之间比较无差异(P=0.388);而LIMAG病变组中自体血管狭窄病变者明显多于LIMAG无病变组(LIMAG病变组:狭窄/闭塞=7支/12支;LIMAG无病变组:狭窄/闭塞=23支/10支),差异有统计学意义(P=0.04)。结论:CABG后桥血管发生病变与冠心病传统的危险因素无明显相关性,术后SVG发生病变与CABG后心绞痛复发时间呈正相关。SVG序贯桥中远期通畅率高于单独桥。单独桥中CABG前自体靶血管血流状况将影响术后LIMAG的转归,而对SVG无明显影响。     

大隐静脉顺行序贯式吻合法在非体外循环冠状动脉旁路移植术中的应用

目的 评价在非体外循环冠状动脉旁路移植术中应用大隐静脉顺行序贯式吻合法的临床效果.方法 对75例冠状动脉粥样硬化性心脏病患者行非体外循环下冠状动脉旁路移植术.左乳内动脉搭桥至前降支,其余各支靶血管以大隐静脉行序贯式搭桥,序贯吻合顺序原则上依次为对角支、回旋支（钝缘支）、左室后支、后降支.结果 全组病例均在非体外循环下完成手术.桥血管吻合数目共296个,平均（3.95±0.55）个/例.全组患者无死亡,无围术期心肌梗死.迟发性心包填塞1例,急性肾功能衰竭1例,上消化道大出血1例,均治愈.结论 非体外循环下采用＂顺行序贯式吻合技术＂行冠状动脉旁路移植手术,可减少主动脉吻合口,节约桥血管长度,并可最快恢复心脏供血,是一种快捷、安全的术式.     

大隐静脉序贯式完全性冠状动脉血运重建远期随访

目的 回顾性研究早期冠状动脉搭桥接受2条序贯式大隐静脉行完全性冠状动脉血运重建患者的远期情况.方法 随访11例患者平均15年存活的情况和大隐静脉桥的改变情况.结果 无手术死亡,5年11例全部存活,10年10例存活,15年9例存话.3例冠状动脉造影2例4个吻合口和1例5个吻合口完全通畅,静脉桥形态良好,1例患者14年接受CTA检查,1条静脉桥因冠状动脉严重钙化而闭塞,另1条序贯式桥良好没有软斑块和钙化.结论 除影响静脉桥远期诸多因素以外,序贯式静脉桥伴高质量的吻合口也是桥远期开放的重要因素之一,应用静脉桥时要确保吻合口的质量.     

大隐静脉Y型冠状动脉搭桥与序贯搭桥术后近中期临床疗效比较

目的 比较并评价大隐静脉Y型冠状动脉搭桥与序贯搭桥术后近中期临床疗效.方法 随机选取2014年1月-2015年12月接受大隐静脉Y型冠状动脉搭桥与序贯搭桥患者各50例为研究对象.将行大隐静脉Y型吻合的患者记为观察组,行序贯吻合的患者记为对照组.对比两组患者术中静脉桥各吻合口血流量及术后3个月、6个月、1年、2年、3年的...     

冠状动脉旁路移植术后桥血管造影特点分析

目的总结冠状动脉旁路移植术(CABG)后桥血管造影特点,分析相关因素对桥血管通畅率的影响。方法选择2004年4月至2006年4月我院CABG术后因心绞痛复发再入院行冠状动脉造影(CAG)的256例患者,男性218例,平均年龄(61.2±9.7)岁。CABG到复查CAG的间隔时间(50.9±40.1)个月。共722支桥血管,其中左乳内动脉(LIMA)桥215支,大隐静脉(SV)桥485支,左桡动脉(RA)桥19支,右乳内动脉(RIMA)桥3支。桥血管造影完全闭塞或狭窄≥75%视为桥血管病变。结果31.6%(228/722)的桥血管发生病变。LIMA桥病变率13.5%(29/215),SV桥病变率39.2%(190/485),RA桥病变率42.1%(8/19),RIMA桥病变率33.3(%1/3)。术后1年内LIMA桥和SV桥病变率分别达14.6%和32.9%,之后随时间缓慢增加。不同靶血管的SV桥通畅率有明显差别。手术年龄<50岁者桥血管病变率增加。性别、序贯吻合及综合危险因素对桥血管通畅率无明显影响。结论CABG术后桥血管病变较常见,是造成术后心绞痛复发的重要原因。LIMA桥的通畅率明显优于SV桥。不同桥血管、不同靶血管、手术年龄均明显影响桥血管通畅率。     

微创经左胸小切口非体外循环单支、多支冠状动脉旁路移植术33例

目的 探讨左侧肋间小切口非体外循环单支、多支冠状动脉旁路移植术的安全性和可行性。方法 回顾性分析2014年5月~2019年10月左胸前外侧小切口非体外循环下冠状动脉旁路移植术33例资料。单支病变17例,多支病变16例。左胸前外侧小切口6cm-10cm,直视下获取左乳内动脉(LIMA),完成LIMA-左前降支(LAD)吻合,升主动脉（Ao）-大隐静脉(SVG)序贯-对角支(D)或中间支（ICA）-钝缘支(OM)-后降支(PDA)或左室后支(PLV)共2~4支旁路移植血管吻合。结果 全组LIMA-LAD桥32例,Ao-SVG-LAD 1例。Ao-SVG-D 2例,Ao-SVG-OM 2例、Ao-SVG-OM-PDA 2例,Ao-SVG-ICA-PDA 3例,Ao-SVG-D-OM-PDA 4例,Ao-SVG-D-OM-PLV 3例。33例手术均顺利完成,围术期无死亡、心肌梗死、脑卒中、呼吸衰竭、肾功能衰竭、切口感染等并发症。术后呼吸机时间7h~18 h(9.14±3.82)h;ICU时间6h~20 h（12±8）h。术后住院5d~11d(8±3)d。出院时复查冠状动脉CT,33例均提示左乳内动脉桥、大隐静脉序贯桥通畅性良好。随访3个月~3年,平均8个月,无死亡、心绞痛和心肌梗死。30例复查冠状动脉, LIMA桥、SVG序贯桥通畅性良好。结论 左侧肋间小切口非体外循环下多支冠状动脉旁路移植术安全可行。     

Improved technique of vascular anastomosis for small intestinal transplantation in rats

AIM To establish a new improved vascular anastomotic technique to simplify the surgical technique and increase the survivsl rate of small intestinal transplantation in rats. METHODS The graft removed en bloc consisted of entire small intestine, portal vein and aortic segment with superior mesenteric artery. The graft was perfused in situ and the gut lumen was irrigated during the operation.Heterotopic small bowel transplantation was performed by microvascular end-to-side anastomosis between the donor aortic segment with superior mesenteric artery and the recipient abdominal aorta, and by the formation of a "Cuff" anastomosis between the donor portal vein and the recipient left renal vein. Both ends of the grafts were exteriorized as stomas. RESULTS A total of 189 intestinal transplantations were performed in rats, 33 of which were involved in the formal experimental group, with a survival rate of 84.8%. The average time for the donor surgery was 80min ±10min; for graft repair 10min ± 3min; and for recipient surgery 95min ± 15min. The average time for the arterial anastomosis and the vein anastomosis was 18min ± 5min and imin,respectively. The warm ischemic time and cold ischemic time were 22min ± 5min and less than 60min, respectively. The whole operation was completed by a single surgeon, the operative time being about 3 hours. CONCLUSION The vascular anastomosis used in this study could simplify surgical technique,reduce the operative time and elevate the survival rate of small intestinal transplantation in rats.     

跳动下冠状动脉搭桥术的手术方针及成绩

目的 比较跳动下冠脉搭桥术（OPCAB）的术式选择对冠心病患者的影响,讨论移植血管的选择及围手术期管理方法 .方法 以我院心脏血管外科从2003年1月至2009年12月所实施的514例冠状动脉搭桥术（CABG）患者作为研究对象,其中体外循环下冠脉搭桥术（C-CABG）32例,OPCAB 482例.结果 术前合并脑血管障碍43例（8.4%）,合并透析16例（3.1%）,合并慢性闭塞性肺病（COPD）17例（3.3%）,既往有经皮冠状动脉成形术（PCI）35例（6.8%）,左主干（LMT）病变179例（34.8%）.平均远端吻合口数（3.6±1.4）个,移植血管全动脉化患者77例（14.9%）,使用左乳内动脉（LITA）患者421例（81.9%）.平均大隐静脉（SVG）使用支数为（1.6±0.5）支/例.术后主要合并症为脑血管病6例（1.1%）,纵隔感染4例（0.7%）,肾功能损害透析（CHDF）7例（1.3%）,房颤（Paf）46例（8.9%）.结论 对于高风险、高难度的CABG应用标准OPCAB术式,采用全动脉化及动、静脉移植血管相组合等低侵袭性手术方法 ,同时做好围手术期管理,可以提高CABG的远期手术成绩.     

体外循环与非体外循环下冠脉旁路移植术后的血管桥通畅比较

目的：比较非体外循环下冠状动脉旁路移植术（OPCABG）与常规冠状动脉旁路移植术（CCABG）术后3-4年时血管桥的通畅率。方法：2003年1月-2004年12月间40例单独行冠状动脉旁路移植术（CABG）的患者资料回顾性地被分为OPCABG组和CCABG组。OPCABG组通过胸骨正中切口,在非体外循环心脏不停跳下完成CABG;CCABG组建立常规体外循环,心脏停搏下完成CABG。两组术前的一般情况无明显区别。利用多层螺旋CT（multislice spiral CT,MSCT）造影检查及CT图像后处理,研究两种术式各条血管桥的通畅情况。结果：CCABG及OPCABG组在左乳内动脉（LI MA）到前降支（LAD）的通畅率分别达到94.1%,94.4%,后降支（PDA）为88.2%,91.6%,钝缘支（包括对角支）的通畅率分别为88.9%,90.9%,静脉桥的通畅率为87.8%,88.0%,动脉桥的通畅率为85.7%,91.3%。各组间统计差别均无显著性。结论：OPCABG旁路血管桥的3-4年通畅率可以和CCABG相媲美.OPCAB治疗冠心病的初期结果显示可以减少术后并发症、减少患者术后呼吸机辅助时间和ICU留观时间、住院时间,降低住院费用,它的普及势在必然。     

Postoperative evaluation of radial artery grafts for coronary artery bypass grafting by transit-time Doppler flow measurements.

Due to the histological configuration of the vessel wall, the radial artery is prone to spasm as a result of handling or harvesting. Therefore, certain degrees of arterial wall spasm are unpreventable, even with appropriate pharmacologic treatment, while using the radial artery as a bypass graft in CABG. Consequently, the radial artery is only reluctantly used compared to saphenous vein grafts in CABG. In our clinical experience, the radial artery, if harvested carefully, has proved to be an excellent bypass graft. This investigation was undertaken to study the differences in blood flow measured directly after extracorporeal circulation in radial artery grafts and venous grafts. Both grafts were compared to the left internal mammarian artery anastomosed to the LAD. METHODS: Between January 1998 and December 1999, 198 patients who were undergoing coronary artery revascularization with two grafts were retrospectively investigated. In all patients, the left internal mammarian artery (LIMA) was anastomosed to the left anterior descending branch (LAD). For the second graft, either the saphenous vein or the radial artery was used. Proximal anstomoses were performed as end-to-side into the ascending aorta. Patients were divided into four groups: Group 1: n = 79 IMA-LAD, vein to the circumflex artery; Group 2: n = 56 IMA-LAD, vein to the right coronary artery; Group 3: n = 34; IMA-LAD, radial artery to the circumflex artery; Group 4: n = 29 IMA-LAD, radial artery to the right coronary artery. Graft-flow measurements were performed using the transit-time method after extracorporeal circulation was terminated. The mean systolic, diastolic, and mean blood flow were measured, and the pulsatility index was calculated. Statistical analysis was performed using the of t-test analysis between the variables mean blood flow and pulsatility index. A p-value of < 0.05 was defined as statistically significant. RESULTS: There were no statistically significant differences in mean blood flow or pulsatility index between radial artery and saphenous vein grafts to the right coronary artery and the circumflex artery, respectively. Also, there were no differences regarding vein grafts to the right coronary artery and to the circumflex artery, or regarding radial artery grafts to the two coronaries, respectively. In group 4, significantly lower blood flow to the LAD was found compared to group 1, and a significantly higher pulsatility index compared to groups 2 and 3. CONCLUSIONS: Radial artery grafts compared to saphenous vein grafts do not show significant differences early after operation in mean blood flow or pulsatility index. Further studies are needed to evaluate long-term performance of radial arteries as coronary bypass grafts and to compare the radial artery to the right mammarian artery and the standard saphenous vein graft.     

颈外动脉-静脉-大脑中动脉吻合后孤立海绵窦段颈内动脉瘤手术技术的改进

目的探讨在颅内外高流量搭桥治疗海绵窦内动脉瘤过程中，保留颈外动脉远端分支及处理保存大隐静脉的方法。方法取下2例患者的大隐静脉显露后，利用压力扩张技术以解除血管痉挛，并存放于保护液中备用；颅内选用大脑中动脉M1、M2交界处或M2段作为受者血管，大隐静脉与受体血管端一侧吻合，而非端一端吻合。在颈部大隐静脉与颈外动脉也行端一侧吻合。结果2例患者手术后，血管造影显示颅内吻合口远端血流充盈良好，颈外动脉远端侧支保留完好，经颅彩色多普勒超声显示，搭桥血管内血流量分别为210ml/min及180ml/min。随访6～9个月，症状均有好转。结论压力扩张技术解除移植血管痉挛，可以简化手术操作；大隐静脉与颈外动脉端一侧吻合，可以保留颈外动脉远端侧支，同时也可达到高流量搭桥的目的。     

非体外循环与常规冠状动脉旁路移植术治疗重症冠心病的对比分析

目的：探讨重症冠心病患者非体外循环下冠状动脉旁路移植术（OPCAB）的可行性和优越性。方法：回顾性分析425例重症冠心病的冠状动脉旁路移植术临床资料。其中非体外循环下冠状动脉旁路移植术（OPCAB组）268例,占63．1％;常规体外循环下冠状动脉旁路移植术（CCABG组）157例。比较两组术后早期死亡率及合并症的发生情况。结果：OPCAB组搭桥（4．09±0．75）支／人,CCABG组搭桥（4．17±0．86）支／人（P〉0．05）。两组新发心房纤颤、围术期心肌梗塞、肾功能不全、肺部并发症发生率差异无显著性（P〉0．05）。与CCABG组比较,OPCAB组手术死亡率、呼吸机使用时间、ICU停留时间、术后输血量、二次开胸率、神经系统并发症发生率明显降低或减少（P〈0．05～〈0．01）。结论：非体外循环下冠状动脉旁路移植术在重症冠心病患者中安全可行,临床效果好。     

Permeability of aortocoronary bypass after 6 months. A multicenter French study

The EPPAC (Etude de la perméabilité des pontages aortocoronaires) is a randomised prospective (18 centres) double blind trial designed to compare the patency of coronary bypass grafts in two groups of coronary patients after surgery: one group treated with oral vitamin-K antagonists and placebo (n = 196, age 57 +/- 5 years, 2.09 grafts/patient) and the other group with vitamin-K antagonists and dipyridamole (n = 182, age 56 +/- 6 years, 1.99 grafts/patient), the principal criterion of evaluation being the patency of the grafts at coronary angiography performed 6 months after surgery, interpreted by two independent observers. Of the 469 patients included (average ejection fraction 59.5 +/- 2.2%), 378 underwent the control coronary angiography at the 6th month and 773 saphenous vein grafts were evaluated. At the end of the study, there were 12 deaths, 10 due to perioperative myocardial infarction, and 24 nonlethal myocardial infarctions. The frequency of occlusion of at least one graft per patient was 18.2%, the patency of the graft at the distal anastomosis was 89.9%. The following factors played a major role: the cardiological center: the occlusion rate per patient ranged from 7.1 to 57.1% and per anastomosis from 2.8 to 28.6%; the internal diameter of the artery grafted: when 2 mm or more, the occlusion rate was 17.6% compared with 42.3% (p less than 0.001); the technique used for distal anastomosis: 9.2% of grafts with single outflow sites occluded, compared with 4.3% of grafts with multiple outflow sites. Early occlusion of saphenous vein aorto-coronary grafts is the main problem of this form of therapy and the addition of dipyridamole to oral anticoagulants does not seem to reinforce the anti-thrombotic effect at 6 months after surgery.     

Coronary flow reserve provided by sequential internal mammary artery grafts

Although internal mammary artery bypass grafts have a high patency rate, the adequacy of blood flow through such conduits, particularly if used sequentially, has been questioned. To evaluate this issue, coronary flow reserve was studied in 20 patients after coronary bypass surgery. Nine patients had sequential internal mammary grafts to the diagonal and left anterior descending coronary arteries; five had a single internal mammary graft to the left anterior descending artery and six had sequential saphenous vein grafts. Fifteen additional single vein grafts were also placed in these patients. Coronary flow reserve was measured after contrast-induced hyperemia by a digital subtraction angiographic technique an average of 25 days after surgery. There was no difference in coronary flow reserve between the proximal and distal anastomotic regions in either the sequential internal mammary graft group (2.14 +/- 0.50 versus 2.29 +/- 0.68, n = 8, p = NS) or the sequential vein group (1.77 +/- 0.49 versus 2.08 +/- 0.78, n = 6, p = NS). In addition, the flow reserve provided to either vascular bed of the sequential internal mammary graft was not different from that provided by a single internal mammary graft (1.64 +/- 0.39, n = 5), a single vein graft (1.95 +/- 0.95, n = 15) or nonstenotic native coronary arteries (2.04 +/- 0.87, n = 34). No cases of intracoronary steal were observed. Although some patients had unequal flow reserves between the proximal and distal anastomotic zones, these occurred in the setting of residual coronary stenoses distal to the site of graft insertion or prior myocardial infarction in the grafted distribution.(ABSTRACT TRUNCATED AT 250 WORDS)     

Experimental studies on the long term fate of the vein and artery grafts and its choice in aortocoronary bypass surgery.

Experimental studies of aorto-coronary bypass were performed using the technique of distal coronary artery perfusion in 47 dogs to ellucidate the flow characteristics at various grafts and long term fate of grafts up to 440 days after operation. On short term results, early graft occlusion seems to occur within 2 weeks with 6.5 days of mean in Group I and II (free grafts) when inflammatory reaction is most prominent. After 2 weeks patency rate was 65% in Group I and II, more than 80% of patency rate were obtained in Group III. In Group IV (prosthetic grafts), all but few (3 cases) could survive for more than 24 hours. In flow characteristic, artery and vein graft of which diameter is larger than that of the coronary artery can maintain enough the basal flow after ligation of the proximal coronary artery. In Group III (IMA-Circumflex anastomosis group), the internal mammary artery must be large enough to carry the blood to coronary artery lest the graft flow becomes below the basal flow. In Group IV, grafts can carry full flow but long term studies were not done because of early graft occlusion. There are much differences between free artery and vein grafts. In artery graft except IMA proper arterial structure is being kept until 440 days but has arteriosclerotic wall changes similar to human being. On the contrary, almost all free vein grafts have subintimal hyperplasia with collagen deposit and fibrous tissue and still progress after one year. These findings demonstrate that ischemia and hydrauiic effect in the graft must be important factor for the irreversible graft wall changes.     

Effect of acetylcholine on arterial and venous grafts and coronary arteries in patients with coronary artery disease

Endothelium-dependent vasomotor responses differ in arteries and veins. The transfer of a given vessel from a different vascular bed into the coronary circulation by grafting may affect its endothelial function. In order to evaluate the differences in endothelial function of the internal mammary artery and aortocoronary venous grafts in patients with coronary artery disease, the response to acetylcholine (ach) was examined and compared with that of native coronary arteries. Eighteen patients were examined, including eight with internal mammary artery grafts (9 days to 48 months after surgery), and 10 with saphenous vein grafts (12-96 months after surgery). Ach (70-700 nmol min-1) was infused selectively into a graft on the left anterior descending coronary artery, and the effect on vessel diameters was assessed by quantitative arteriography. In both groups 84% and 83%, respectively, of the arterial segments distal to the bypass anastomosis were contracted by ach (greater than or equal to 70 nmol min-1). The segments of both groups did not show angiographic evidence of local atherosclerosis. A complete occlusion occurred in four cases. In contrast, internal mammary artery grafts were not contracted by ach; in four of 12 segments a dilatation was observed, whereas five of 20 aortocoronary venous graft segments showed a slight reduction in lumen diameter after the highest ach dose applied. The vasoconstricting effect of ach was reversed by intracoronary nitroglycerin. By using ach as an indicator of endothelial dysfunction it is concluded that the internal mammary artery grafts maintained an intact endothelial function after surgery, whereas the coronary artery segments showed an impaired endothelium-dependent vasodilatation. Some of the venous graft segments reacted as coronary arteries did with a less pronounced cholinergic vasoconstriction. This in vivo study supports the observation of a functional superiority of internal mammary artery over saphenous vein coronary grafts.