OPCAB即时与关胸时乳内动脉桥血流的对比研究

目的　使用即时超声血流探测仪对比观察非体外循环冠状动脉旁路移植术 (OPCAB)术中左乳内动脉 (LIMA)桥吻合完毕当时 (早期 )与关胸时 (晚期 )桥血流变化规律。方法　 2 0 0 2年 1月至 8月 ,对 6 5例OPCAB病人进行了早期与晚期动脉桥血流的对比研究。其中男 5 0例 ,女 15例 ;年龄 47～ 75岁 ,70岁以上病人 19例 ( 2 9 2 %)。病人均为不稳定型心绞痛 ,其中冠状动脉三支病变 32例 ( 49 2 %) ,二支病变 2 6例 ( 40 0 %) ,单支病变 7例 ( 10 8%)。OPCAB术中常规使用LIMA与左前降支 (LAD)吻合。于LIMA与LAD吻合完毕和手术结束关胸前 ,用即时血流测量仪 (transit timeflowmeter)直接测量并记录LIMA桥血流波形、平均流量、舒张期流量、收缩期流量、搏动指数及平均动脉压。结果　两组平均动脉压差异无显著性 (P =0 0 5 ) ;LIMA桥平均血流量早期 ( 2 9 91± 3 32 )ml min显著高于晚期 ( 2 5 12± 2 5 6 )ml min ,P =0 0 3;舒张期流量早期 ( 5 9 2 6± 5 2 1)ml min与晚期 ( 5 4 36± 4 2 7)ml min差异无显著性 ,P =0 0 8;收缩期流量早期 ( 12 98± 1 6 4)ml min显著高于晚期 ( 6 17± 1 93)ml min ,P <0 0 0 1;搏动指数早期 2 6 9± 0 12明显小于晚期 3 36± 0 37,P =0 0 2。结论　LIMA与LAD吻合     

非体外循环心脏跳动下冠状动脉旁路移植术桥血流的研究

目的　术中测量非体外循环心脏跳动下冠状动脉旁路移植术 (OPCAB)桥血管的血流量和搏动指数 (PI)及血流波形 ,以探讨血管桥通畅率及其与波形的关系。方法　 2 34例病人接受OPCAB手术 ,采用左乳内动脉 (LIMA)全部与左前降支 (LAD)吻合 ,大隐静脉 (SV)吻合口在 2个以上采用序贯式吻合。术中用超声血流检测仪 (medi stimbutterflyflowmeter)测量旁路血管桥的血流量、PI值及其波形 ,根据结果判断桥路通畅情况 ,并且对比LIMA和SV旁路血管桥的血流量和LIMA中LAD近段狭窄大于 90 %与小于 90 %者的血流量。结果　LIMA使用率 10 0 % ,LIMA和SV桥通畅率 10 0 % ,LIMA平均血流量(19 99± 1 93)ml/min ,SV血流量 (38 17± 2 85 )ml/min ,两者差异显著 (P <0 0 1)。LIMA组中LAD近段狭窄大于 90 %者血流量 (32 0 0± 3.4 0 )ml/min ,小于 90 %者血流量 (15 2 9± 1 6 6 )ml/min ,两者差异显著(P <0 0 1)。PI平均值LIMA为 3 2 9± 0 2 2 ,SV为 3 4 1± 0 37。术后病人无并发症 ,心绞痛消失 ,全部治愈出院 ,平均住院 (7 0± 1.5 )d。随访无死亡。结论　OPCAB术吻合口的通畅率令人满意 ,静脉桥血流量高于LIMA ;LAD近段狭窄大于 90 %时LIMA血流量较高。反映桥通畅的最可靠指标是桥血流的搏动指数 ,而舒张期血流的波     

冠状动脉旁路移植术瞬时测血流量技术的临床应用

目的　总结瞬时测血流量 (TTFM)技术在冠状动脉旁路移植术 (CABG)中的应用经验 ,探讨异常血管桥瞬时血流量技术参数特点、发生原因及处理方法。方法　 2 0 0 1年 9月至 2 0 0 2年 5月 ,连续对5 0例不停跳冠状动脉旁路移植及 40例常规体外循环下旁路移植者进行血管桥血流量测定 ,随机 30例进行左侧乳内动脉 (LIMA)血流量测定。结果　 30例LIMA离断后TTFM参数 :平均血流 (42 9± 33 0 )ml min ,弹力指数 (PI)值 1 0 0± 0 6 4,波形曲线为收缩期、舒张期双向血流 ,收缩期为主 ,实际平均血流为(37 4± 2 8 8)ml min ,相关系数为 0 98。 90例冠状动脉旁路移植TTFM参数 :LIMA到左前降支 (LAD)平均流量 (2 9 9± 9 5 )ml min ,平均PI值 2 47± 0 88。大隐静脉或桡动脉到回旋支系统平均流量 (33 7±17 5 )ml min ,PI值 4 0± 1 9;到右冠状动脉系统 ,平均流量 (31 5± 19 2 )ml min ,PI值 2 6± 1 3 ;到前降支及回旋支系统为双向血流 ,血流以舒张期为主 ,收缩期可形成负值 ;到右冠状动脉系统 ,收缩及舒张期为双向灌注 ,较少出现负值。TTFM技术提示 ,2 87支血管桥中有质量问题血管桥 6支 ,均手术证实并加以矫正。 90例病人均无围术期心肌梗死及其它严重并发症 ,无死亡。随访 2～ 10个月 ,病人无心绞痛及心肌     

国人桥血流搏动指数的研究

目的　研究冠状动脉旁路移植术 (CABG)国人桥血流的搏动指数 (PI值 )合适的范围。方法　将 35 7例CABG病人分为二组 ,不停跳 (OPCAB)组 2 6 3例 ,停跳 (CCABG)组 94例。常规用原位带蒂左乳内动脉 (LIMA)与左前降支 (LAD)吻合 (LIMA组 ) ,其余桥使用大隐静脉 (SV组 )。SV吻合口多于 2个时采用序贯式吻合 ,近端吻合于升主动脉。移植完毕动脉血压稳定后 ,用直径为 2～ 3mm超声微探头直接测量LIMA和SV桥的平均血流量、收缩期和舒张期血流量以及PI值 ,并记录血流波形。确定PI值“合适”的标准 :舒张期血流波形良好 ;平均血流量大于 10ml min ;术中及术后CK MB、cTnI在正常范围和无ECG改变及手术后临床症状改善等。结果　各组测量桥血流时血压差异无显著性。共测量LIMA 35 7根 ,SV 32 4根。LIMA之PI值 :OPCAB为 2 4 9± 0 91,CCABG为 2 39± 1 16 ;SV之PI值 :OPCAB为 2 6 8±1 35 ,CCABG为 2 5 9± 1 4 2 ;各组间PI值差异无显著性 (P >0 0 5 )。用全部PI值计算出总体平均值为2 5 6± 2 35 (95 %置信度 )。结论　国人冠状动脉旁路移植术桥血流的PI的参考值范围为小于 5。     

体外循环与非体外循环冠状动脉旁路移植术患者桥血流的对比研究

目的比较非体外循环和体外循环下冠状动脉旁路移植术(CABG)的左乳内动脉(LIMA)和大隐静脉(SV)桥血流的变化。方法将547例行CABG患者分为非体外循(OPCAB)组(403例)和体外循环(CCABG)组(144例)。常规用LIMA与左前降支(LAD)吻合,其余靶血管使用SV吻合。于全部吻合口吻合完毕血流动力学稳定情况下,用即时血流测量仪(TTFM)直接测量并记录桥血流各项参数。结果搏动指数(PI值)、无效血流率及舒张期峰流量,LIMA桥OPCAB组分别为2.7±1.8,(2.2±4.3)%,(46.8±2.7)m l/m in,CCABG组分别为2.8±2.0,(3.4±3.1)%,(52.8±3.7)m l/m in;SV桥,OPCAB组分别为2.8±0.1,(1.8±0.3)%,(85.8±3.2)m l/m in,CCABG组分别为2.6±0.2,(1.3±0.2)%,(93.9±5.6)m l/m in,两组比较差异均无统计学意义(P均>0.05);平均流量及收缩期峰流量,CCABG组[SV桥(62.9±3.9)与(106.9±7.3)m l/m in,LIMA桥(32.5±23.5)与(41.6±4.4)m l/m in]均大于OPCAB组[SV桥(47.2±1.7)与(58.0±2.7)m l/m in,LIMA桥(26.5±19.9)与(27.0±1.6)m l/m in],差异有统计学意义(t=6.61,6.77,5.16,5.96,P均<0.01);CCABG组血管阻力LIMA桥与SV桥分别为(3.6±0.3)与(1.6±0.2)mm Hg.m l-1.m in-1,小于OPCAB组的(4.7±0.2)与(2.7±0.1)mm Hg.m l-1.m in-1,两者比较差异有统计学意义(t=4.32,P均<0.01)。结论CCABG组与OPCAB组对比,桥血管的通畅率无显著性差别。     

Symmetry主动脉吻合器在心脏不停跳冠状动脉旁路移植术中的应用

目的　总结非体外循环心脏不停跳冠状动脉旁路移植术 (Off-pumpcoronaryarterybypassgrafting ,OPCAB)中使用Symmetry主动脉吻合器的近期效果。　方法　 2 0 0 2年 9月～ 2 0 0 3年 6月 ,2 0 4例冠心病行OPCAB ,其中 16 7例使用大隐静脉移植物 ,应用Symmetry主动脉吻合器 10 0例。　结果　使用吻合器 14 2个 ,吻合失败弃用 2个 ,3个吻合口漏血需手工修补 ,成功率 96 5 % (137 14 2 ) ,近端吻合口 (1 4± 0 5 )个 例 ,远端吻合口 (3 5± 0 8)个 例。近端吻合口血流量 (46 5± 2 2 3)ml min。吻合器安装时间 (4 0± 1 1)min ,吻合口完成时间均在 10s以内 ,手术时间 (3 2± 0 4 )h。手术死亡率 1% (1 10 0 ) ,无围手术期心肌梗塞、脑卒中等并发症 ,出血二次开胸 1例 ,但非吻合口出血。术后引流量 (5 4 1± 2 74 )ml,输血率 36 0 % (36 10 0 )。术后住院 (7 8± 1 6 )天。　结论　Symmetry主动脉吻合器可安全有效地应用于CABG术 ,近期临床效果满意 ,可缩短吻合时间和手术时间 ,避免主动脉钳夹 ,降低卒中并发症     

经上腔静脉逆行灌注脑保护在主动脉瘤手术中的应用

目的　探讨在主动脉瘤手术中应用经上腔静脉逆行灌注的脑保护效果。　方法　 65例主动脉瘤患者分 2组 ,15例采用深低温停循环 (DHCA) ,5 0例经上腔静脉逆行灌注 (RCP)进行脑保护。术中比较 2组患者不同时间颈内静脉的血乳酸含量 ,对部分RCP患者测定了灌注血和回流血的流量分布 ,以及灌注血和回流血的氧含量。　结果　DHCA组停循环时间为 10 0～ 63 0min ,平均(3 5 9± 18 8)min ;RCP组为 16 0～ 81 0min ,平均 (45 5± 17 2 )min。术后至清醒时间DHCA组为4 4～ 9 4h ,平均 (7 1± 1 6)h ;RCP组 2 0～ 9 0h ,平均 (5 4± 2 2 )h。DHCA组手术死亡 3例 ,RCP组死亡 1例 ;术后神经系统并发症DHCA组 3例 (死亡 2例 ,成活 1例 ) ,RCP组 1例 (存活 )。手术总成功率和神经系统并发症发生率RCP组分别为 96%和 2 % ,DHCA组为 67%和 2 0 % (P <0 0 5 )。RCP组再灌注期间颈内静脉血乳酸含量增高幅度低于DHCA组 [(4 4± 0 6)mmol/Lvs (6 2± 0 9)mmol/L ,P <0 0 1],经头臂和下腔静脉血流量测定显示约 2 0 %血液经头臂动脉回流 ,灌注血和回流血氧差9 0 0～ 13 67ml/L ,证实RCP期间脑组织有氧利用。　结论　在主动脉瘤手术中 ,应用RCP可以延长停循环的安全时限 ,是可行的脑保护方法     

冠状动脉竞争血流对乳内动脉旁路血流及NO、ET含量影响的实验研究

目的研究冠状动脉旁路移植（CABG）术后,未完全闭塞冠状动脉的竞争血流对左乳内动脉（加雌）旁路血流量、方向及旁路血流中一氧化氮（NO）、内皮素（ET）含量的影响。方法15只猪行㈣术建立不同程度狭窄的冠状动脉左前降支（LAD）与LIMA旁路血管竞争血流动物模型,并检测LIMA旁路血流中NO、ET含量。结果LAD近端狭窄程度越轻,LIMA旁路平均血流量越小,且收缩期逆向血流越大,IAD近端30％狭窄、50％狭窄时LIMA旁路的血流量均明显低于90％狭窄时（P〈0．01）。IAD近端30％和50％狭窄时旁路血流NO含量均明显低于IAD近端90％狭窄时（P〈0．05）;LIMA旁路血流中ET含量均较移植前高（P〈0．05）。结论CABG术后,来自未完全闭塞冠状动脉的竞争血流导致加雌旁路血流量下降并产生双向血流,进而引起旁路血流中NO含量显著下降,可能是早期LIMA血管旁路闭塞的主要机制。     

常规与非体外循环下冠状动脉3支病变旁路移植血管通畅性对比分析

目的　评价非体外循环下冠状动脉旁路移植术 (OPCAB)与体外循环下冠状动脉旁路移植术 (CCABG)治疗冠状动脉三支病变术中旁路早期通畅性。方法　 6 0例 3支血管病变的病人分为OPCAB组和CCABG组 ,每组各 30例。行冠状动脉旁路移植术 ,OPCAB组胸骨正中切口 ,在非体外循环心脏不停跳下完成手术 ;CCABG组建立常规体外循环 ,心脏停跳下完成手术。术中应用即时血流测量技术对旁路血管进行流量测量。对比分析两组术前、术后的各项指标及各血管旁路流量、搏动指数和血流波形。结果　两组病人术前一般情况差异无统计学意义。OPCAB组与CCABG组移植旁路血管分别为 (3 6±0 6 )支与 (4 3± 0 9)支 (P <0 0 1) ;两组前降支及右冠状动脉旁路血流量、搏动指数差异无显著性。CCABG组回旋支序贯旁路和远端吻合口多 ,血流量较OPCAB组高。两组弥漫病变血管旁路血流量小。结论　OPCAB与CCABG治疗 3支病变 ,两组血管旁路早期通畅性差异无显著性。     

腹腔镜与经腹鞘膜内子宫切除术的临床对照分析

目的 :探讨腹腔镜鞘膜内子宫切除术的优越性及临床应用价值。方法 :15 2例行腹腔镜鞘膜内子宫切除术 (腹腔镜组 ) ,与同期 138例经腹鞘膜内子宫切除术 (开腹组 )进行比较。结果 :腹腔镜组平均手术时间 86 6 7± 18 89min ,术中平均出血量 12 4 5 3± 5 3 2 2ml ;对照组平均手术时间 83 5 0± 14 72min ,术中平均出血量 114 4 2± 5 0 36ml,两组差异无显著性 (P >0 0 5 )。腹腔镜组术后排气时间为 2 6 80± 4 6 3h ,术后最高体温为 37 5 1± 0 33℃ ,术后住院天数为 4 0 2± 0 89d ;开腹组术后排气时间为 32 4 6± 6 2 3h ,术后最高体温为 38 0 9± 0 2 9℃ ,术后住院天数为 5 96± 1 0 3d ,两组差异有高度显著性 (P <0 0 0 1)。术后病率 ,腹腔镜组无 1例 ,开腹组 7例 (5 % )。腹腔镜组 1例膀胱损伤 ,镜下修补 ,开腹组无损伤。结论 :腹腔镜鞘膜内子宫切除术具有腹壁创伤小 ,术中出血少 ,术后康复快及并发症少等优点 ,是较理想的子宫切除术式     

冠状动脉硬化性心脏病合并左锁骨下动脉严重狭窄非体外循环下同期手术的临床经验

目的探讨非体外循环冠状动脉旁路移植同时主动脉-锁骨下动脉旁路治疗冠状动脉硬化性心脏病(冠心病)合并锁骨下动脉重度狭窄的手术方法及效果.方法2003年1月～2004年5月,我院治疗须行冠状动脉旁路移植术同时合并左锁骨下动脉近端重度狭窄3例,术中先行主动脉-锁骨下动脉旁路,左乳内动脉获得满意的流量后,再行非体外循环冠状动脉旁路移植.结果手术时间210～340 min,平均283 min,出血量570～1 630 ml,平均963 ml.游离左乳内动脉后量杯测流量均＜5 ml/min,主动脉-锁骨下动脉旁路后量杯测流量均＞50 ml/min,乳内动脉远端与前降支吻合后流量仪测流量12～27 ml/min,平均20 ml/min.术后临床症状缓解,未发现冠脉-锁骨下动脉窃血综合征.3例随访3～6个月,平均5个月,无心绞痛发作.结论非体外循环冠状动脉旁路移植同时主动脉-锁骨下动脉旁路手术是治疗冠心病合并锁骨下动脉重度狭窄简单而有效的方法.     

Assessment of left mammary artery grafts (LIMA) to left anterior descending artery (LAD) after off-pump coronary artery bypass grafting by color Doppler.

BACKGROUND: Off-pump coronary artery bypass grafting (OPCAB) on a beating heart with a LIMA graft to the LAD is established for patients with one vessel disease. The aim of the study was to assess the LIMA patency noninvasive by transcutaneous duplex ultrasound. METHODS: 25 patients (16 male, 9 female, mean age 58+/-13 yr) with LIMA grafts to LAD by OPCAB procedures were studied 7-20 days after surgery. Doppler velocity parameters were measured by use of a 7 MHz transducer placed in left intercostal space. The conventional coronary angiographies performed showed the LIMA graft patent. RESULTS: In all cases a typical biphasic pattern of blood flow was recorded with forward flow in both systole and diastole respectively. Under basal conditions the mean peak velocities in systole were 0.36 m/s and the mean peak velocities in diastole were 0.27 m/s with a mean systolic/diastolic ratio of 1.33. CONCLUSION: Transcutaneous Doppler ultrasound is useful in the detection of the LIMA graft flow. This non-invasive technique may find applications for routine postoperative follow-up of patients with LIMA grafts.     

心脏不停跳冠状动脉旁路移植术中应用8-0 Prolene缝线的即时血流效果评价

目的探索采用8-0 Prolene缝线进行移植血管远端吻合的即时效果。方法分别选取2010年和2012年在北京安贞医院心外科行不停跳冠状动脉旁路移植术的患者共101例,男87例、女14例,年龄46～82（61.35±8.24）岁。2010年的36例患者全部使用目前国内外常规使用的7-0 Prolene缝线缝合冠状动脉远端吻合口,2012年的65例患者全部使用8-0 Prolene缝线缝合冠状动脉远端吻合口。吻合完毕后全部应用即时血流测量仪测量与前降支吻合的移植血管（左乳内动脉和大隐静脉）的血流相关指标,包括血流量、搏动指数（PI）和舒张期血流灌注率,将分别应用7-0 Prolene和8-0 Prolene两种吻合缝线吻合的移植血管的测量数据进行比较。结果采用8-0Prolene缝线吻合的左乳内动脉桥（n=44）的血流量值较7-0 Prolene缝线吻合的左乳内动脉桥（n=30）血流量值明显增加[（33.70±21.13）ml/min vs.（27.50±17.34）ml/min,P=0.032],同时搏动指数明显减小（2.15±0.69 vs.2.58±1.01,P=0.047）。而8-0 Prolene缝线吻合后大隐静脉桥（n=21）的血流量值和搏动指数与7-0 Prolene缝线进行吻合的大隐静脉桥（n=6）差异无统计学意义[（34.19±16.00）ml/min vs.（29.00±15.48）ml/min,P〉0.05;2.07±0.53 vs.1.95±0.55,P〉0.05]。所有移植血管的舒张期血流灌注率均大于50%,且组间差异无统计学意义（P〉0.05）。结论使用8-0 Prolene缝线进行左乳内动脉与前降支的吻合可以提高移植血管的血流量同时降低其搏动指数,吻合口即时通畅性更佳,将有利于提高手术的成功率及预后。     

Phasic coronary blood flow pattern during a continuous flow left ventricular assist support.

OBJECTIVE: Continuous flow left ventricular assist devices (LVADs) have been introduced and tested as a bridge to heart transplantation, bridge to recovery, and destination therapy, and several studies have been conducted to assess the physiologic effects of continuous flow LVADs. However, the effect of reduced pulsatility on the phasic coronary blood flow pattern is unknown. The aim of this study was to investigate the phasic coronary blood flow patterns during continuous flow LVAD support. METHODS: Phasic coronary blood flow patterns and hemodynamic data were analyzed using three flow probes placed around the left anterior descending coronary artery (LAD), left circumflex coronary artery (LCX), and the right coronary artery (RCA) in 16 pigs before and after initiating the LVAD support with or without creating LAD stenosis. RESULTS: The total coronary blood flow (TCBF, 112.8+/-31.4 mL/min) gradually decreased when the continuous flow LVAD support increased to 2.0 L/min (110.7+/-29.0 mL/min, P = 0.571), 2.5 L/min (103.7+/-26.1 mL/min, P = 0.079), and 3.0 L/min (101.5+/-27.2 mL/min, P = 0.027) because of decreases in LAD flow and LCX flow. LVAD support caused decrease in systolic and peak systolic LAD flow, LCX flow, and RCA flow, whereas diastolic RCA flow increased. In the presence of LAD stenosis, the TCBF (97.7+/-36.1 mL/min) decreased when the continuous flow LVAD support increased to 2.0 L/min (83.9+/-22.1 mL/min, P = 0.029), 2.5 L/min (83.2+/-25.2 mL/min, P = 0.012), and 3.0 L/min (87.6+/-23.4 mL/min, P = 0.005) because of decreases in LCX flow. CONCLUSION: Use of a continuous flow LVAD decreased TCBF, LAD flow, and LCX flow secondary to reduced systolic LAD flow and LCX flow, and decreased TCBF and LCX flow in the presence of LAD stenosis. These findings are potentially relevant to understanding the physiology of myocardial blood perfusion during continuous flow LVAD support especially in patients with coronary artery disease.     

Dopexamine increases internal mammary artery blood flow following coronary artery bypass grafting.

OBJECTIVE: Vasoactive agents and inotropes influence conduit-coronary blood flow following coronary artery bypass grafting (CABG). It was hypothesized that dopexamine hydrochloride, a dopamine A-1 (DA-1) and beta(2) agonist would increase conduit-coronary blood flow. A prospective randomized double blind clinical trial was carried out to test this hypothesis. DA-1 receptors have previously been localized to human left ventricle. METHODS: Twenty-six American Society of Anaesthesiology class 2-3 elective coronary artery bypass graft patients who did not require inotropic support on separation from cardiopulmonary bypass (CPB) were studied. According to a randomized allocation patients received either dopexamine (1 microg/kg per min) or placebo (saline) by intravenous infusion for 15 min. Immediately prior to and at 5,10 and 15 min of infusion, blood flow through the internal mammary and vein grafts (Transit time flow probes, Transonic Ltd.), heart rate, cardiac index, mean arterial pressure and pulmonary haemodynamics were noted. The data were analysed using multivariate analysis of variance. RESULTS: Low-dose dopexamine (1 microg/kg per min) caused a significant increase in mammary graft blood flow compared to placebo at 15 min of infusion (P=0.028, dopexamine group left internal mammary artery (LIMA) flow of 43.3+/-14.2 ml/min, placebo group LIMA flow at 26.1+/-16.3 ml/min). Dopexamine recipients demonstrated a non-significant trend to increased saphenous vein graft flow (P=0.059). Increased heart rate was the only haemodynamic change induced by dopexamine (P=0.004, dopexamine group at 85.2+/-9.6 beats/min and placebo group at 71.1+/-7.6 beats/min after 15 min of infusion). CONCLUSION: This study demonstrates that administration of dopexamine (1 microg/kg per min) was associated with a significant increase in internal mammary artery graft blood flow with mild increase in heart rate being the only haemodynamic change. Low-dose dopexamine may improve graft flow in the early post CABG period with minimal haemodynamic changes.     

Epicardial coronary artery Doppler: validation in the animal model

The aim of the study was to validate a newly-designed epicardial coronary artery Doppler probe and test its detection of changes in coronary blood flow velocity. Left anterior descending (LAD) coronary blood flow and flow velocity were evaluated in four pigs with a pericoronary transit time flow (TTF) probe and a newly-designed epicardial Doppler micro-probe. Four consecutive measurements were taken for each of the following conditions: basal, partial stenosis, occlusion, and reperfusion of the LAD. Mean TTF value (ml/min) was 23.2+/-6.6 in basal condition, 16.2+/-5.7 after partial LAD stenosis, 0.1+/-0.3 during LAD occlusion, and 67.4+/-23.3 at reperfusion (P<0.001). Similar patterns were recorded in terms of Doppler velocity (cm/s) with values of 4.0+/-1.9 in basal condition, 3.5+/-2.3 after partial LAD stenosis, 0.5+/-1.4 during LAD occlusion, and 11.1+/-5.5 at reperfusion (P<0.001). No significant differences in both TTF and Doppler velocity were detected between basal condition and partial LAD stenosis (P=ns). Epicardial coronary arterial Doppler represents a valuable tool to detect coronary arterial flow velocity in basal condition. Although changes in flow velocity are easily recorded after coronary occlusion and reperfusion, modifications after partial coronary stenosis are not clearly defined.     

Acute effects of 17beta-estradiol on left internal mammary graft after coronary artery bypass grafting

BACKGROUND: Vasospasm of arterial conduits used for coronary surgical procedures is an important cause of postoperative graft failure. Mounting experimental evidence suggests that estrogen reverses acetylcholine-induced vasospasm of the coronary arteries in animals and humans. Estrogen also affects endothelium-derived constrictor factors. We therefore investigated the in vivo vasomotor responses to transdermal 17beta-estradiol of the left internal mammary artery (LIMA) grafted on the anterior descending coronary artery. METHODS: We studied 20 women, mean age of 62 +/- 7.2 years (range, 48 to 73 years), who had undergone cardiopulmonary bypass for coronary artery bypass grafting. They received transdermal 17beta-estradiol on the fifth day after operation. The diameter, cross-sectional area, and blood flow of the LIMA graft were measured by transthoracic color Doppler echography before (basal values) and after the transdermal administration of 50 microg of 17beta-estradiol (control). RESULTS: LIMA graft vasodilation after the administration of 17beta-estradiol was observed. A significant increase in diameter (2.06 +/- 0.4 mm versus 2.37 +/- 0.28 mm; p = 0.035) and cross-sectional area (3.45 +/- 1. 2 mm2 versus 4.24 +/- 1 mm2; p = 0.039) was registered. The LIMA graft mean flow increased by 49% (44.76 +/- 27.19 mL/min versus 56.62 +/- 27.69 mL/min), but this increase was not statistically significant (p = 0.06). CONCLUSIONS: The acute postoperative transdermal administration of 17beta-estradiol induced a significant increase of LIMA graft diameter and cross-sectional area in postmenopausal women who underwent coronary artery bypass grafting. The LIMA graft vasodilation was also associated with an improvement in LIMA blood flow.     

Lambda graft with the radial artery or free left internal mammary artery anastomosed to the right internal mammary artery: flow dynamics

BACKGROUND: The aim of this study was to evaluate the outcome and flow dynamics of the lambda graft configuration, relative to a second arterial graft. METHODS: From 1998 to 2000, 47 patients (mean age 55.5 +/- 4.7 years) with triple-vessel disease underwent arterial revascularization using the lambda graft. The in situ left internal mammary artery (LIMA) and right internal mammary artery (RIMA) were anastomosed to the left anterior descending (LAD) and obtuse marginal arteries, respectively. In 21 patients (group I) presenting proximal or middle-third LAD or right coronary (RC) arterial stenoses, the lambda graft was constructed by anastomosing the distal LIMA, as a free LIMA graft, to the RC and proximally to the in situ RIMA. In the other 26 patients (group II) presenting with middle-distal third LAD or RC arterial stenoses, the radial artery (RA) was used to construct the lambda graft. All patients underwent transthoracic echo color Doppler before and after an adenosine test at 1 week and 3 months after operation. RESULTS: There were no hospital deaths. Overall, 47 lambda grafts were constructed. There was no difference between baseline and maximal flows and coronary flow reserve (CFR) between groups. CFR at IMA stems increased in both groups within 3 months versus 1 week [(LIMA)CFR = 2 +/- 0.3 vs 2.3 +/- 0.3 (p = 0.002) and (RIMA)CFR = 2.2 +/- 0.4 vs 2.5 +/- 0.3 (p = 0.009) in group I, and (LIMA)CFR = 2.12 +/- 0.33 vs 2.4 +/- 0.35 (p = 0.005) and (RIMA)CFR = 2.17 +/- 0.32 vs 2.52 +/- 0.26 (p = 0.001) in group II]. At 3 months versus 1 week, the (RIMA)diameter(i) (mm) at rest was 1.69 +/- 0.32 versus 1.48 +/- 0.2 (p = 0.015) in group I and 1.66 +/- 0.3 versus 1.47 + 0.2 (p = 0.01) in group II. At 6 +/- 2.4 months, all patients were free of angina. CONCLUSIONS: These data, almost identical for free LIMA and RA to RIMA using the lambda graft, demonstrate that RIMA flow reserve is adequate for multiple coronary anastomoses irrespective of the second arterial graft.