非体外循环冠脉搭桥术中的血液动力学和氧代谢的变化

目的 观察非体外循环冠脉搭桥术（OPCABG）中的血液动力学及氧代谢参数的变化,并分析其麻醉处理特点。方法 择期行OPCABG手术患者87例。均采用芬太尼、异氟醚、笑气、异丙酚行静吸复合全麻。采用肺动脉漂浮导管和连续心排血量方法测定血液动力学,分别在手术前（T1）、锯胸骨后（T2）、吻合血管桥前（T3）、吻合前降支时（T4）、吻合后降支或右冠状动脉时（T5）、吻合左回旋支或对角支时（T6）、血管吻合完成并恢复心脏自然位置（T7）、闭合胸骨前（T8）及手术结束时（T9）等时间点测定及计算血液动力学参数;分别在上述的T1、T2、T3、吻合开始后1.5h（T4-）、及T9的5个时间点检测动脉、混合静脉血气,并进一步计算氧代谢参数包括氧供8指数（DO2I）、氧耗指数（VO2I）、氧摄取率（ERO2）等。记录术后拔气管导管时间及ICU停留时间。结果 与T1相比,T2与T3的HR、CO、CI、PAWP、MPAP、LVWI、RVWI、RVSWI、DO2I、SO2、PO2均显著增加（P〈0.05或0.01）,而VO2I与ERO2明显降低（P〈0.05或0.01）,但SI、LVSWI和PVRI无显著性改变（P〉0.05）。在吻合靶血管过程中（T4、T5、T6）,CI、SI、MAP、LVWI、LVSWI、RVWI、RVSWI、DO2I、SO2、PO2、VO2I等不同程度地降低（P〈0.05或0.01）,而HR、RAP、MPAP、PAWP和ERO2则显著增高（P〈0.05或0.01）。血管吻合完毕后至术毕（T7、T8、T9）各项参数均逐渐恢复至T1水平或明显改善。术后平均6.5±2.3h拔除气管导管,ICU停留时间为2.6±1.4d。结论 在可靠的血液动力学监测和合理使用血管活性药物情况下,OPCABG病人可安全地渡过吻合靶血管时的循环波动期,恢复机体的氧供需平衡。     

七氟醚诱导及维持麻醉对心脏瓣膜手术病人血液动力学的影响

目的:研究七氟醚及七氟醚-N_2O吸入诱导及维持麻醉对心脏瓣病人血液动力学的影响。方法:44例患者分两组,组1以七氟醚、组2以七氟醚-N_2O诱导,均以七氟醚-N_2O维持麻醉。采用SwanGanz导管技术监测血液动力学变化。结果:诱导过程病人舒适,入睡平稳,几无呛咳屏气及躁动等不良反应发生。诱导后两组HR、PTRI、PVRI和SVRI无变化,但MAP、CI、LVWI、LVSWI及RVWI明显降低(P<0.05),组1尚伴SI和RVSWI减低(P<0.05)。劈胸骨后,两组RAP、PTRI、PORI、SVRI增高,CI、SI、LVWI、LVSWI、RVWI及RVSWI进一步减低(P<0.05)。CPB开始前,两组LVWI、LVSWI、RVWI及RVSW仍继续下降(P<0.01)。结论:心脏瓣膜病人以1.0 MAC七氟醚或1.2 MAC七氟醚-N_2O诱导是可取的,但以此浓度维持麻醉,对强烈刺激反应的抑制仍嫌不足。     

非心肺转流冠状动脉旁路移植术中心脏循环效率变化趋势的分析

目的采用压力波形分析技术(pressure recording analytical method,PRAM)分析非心肺转流冠状动脉旁路移植术(off-pump coronary artery bypass grafting,OPCABG)中心脏循环效率(cardiac cycle efficiency,CCE)等血流动力学参数的变化趋势。方法选择2017年3—9月拟于全麻下行择期OPCABG患者43例,男36例,女7例,年龄45~75岁,ASAⅡ或Ⅲ级,心功能Ⅱ或Ⅲ级。应用MOSTCARE监护仪(核心技术为PRAM)监测患者麻醉结束后(T_1)、吻合前降支(T_2)、吻合对角支(T_3)、吻合回旋支(T_4)、吻合后降支(T_5)、搭桥完成后(T_6)、术毕(T_7)时的血流动力学参数,包括CCE、最大压力梯度(dp/dt)、MAP、HR、心脏指数(cardiac index,CI)、每搏指数(stroke volume index,SVI)、心搏量变异度(stroke volume variability,SVV)、外周血管阻力指数(systemic vascular resistance index,SVRI)。结果与T_1时比较,T_2—T_6时CCE明显降低(P0.01),且CCE在以上时点均下降为负值,T_5时下降至最低。与T_1时比较,T_2—T_7时dp/dt、CI、SVI、SVRI明显降低(P0.05);HR明显增快,SVV明显升高(P0.05),但仍处于正常范围内。T_2—T_6时CCE与dp/dt呈明显正相关(P0.05);T_1—T_4、T_7时CCE与CI、SVI呈明显正相关,与SVRI呈明显负相关(P0.01);T_1、T_7时CCE与SVV呈明显负相关(P0.01)。结论在靶血管吻合过程中,尽管CI、SVI、SVRI等参数仍在正常范围,但CCE却有明显降低并至负值,吻合后降支时降至最低,且恢复较其他血流动力学参数缓慢。     

混合静脉血氧饱和度反映非体外循环冠状动脉旁路移植术中CO变化的准确性

目的 评价混合静脉血氧饱和度(S(-v)O2)反映非体外循环冠状动脉旁路移植(OPCABG)术中CO变化的准确性.方法 择期行OPCABG的病人25例,年龄50～75岁,体重55～85 kg,NYHA心功能分级Ⅰ～Ⅲ级.静脉注射咪达唑仑、芬太尼、哌库溴铵和依托咪酯麻醉诱导,气管插管后行机械通气.麻醉诱导后,右颈内静脉置入漂浮导管,监测S(-v)O2和CI.静脉注射芬太尼和哌库溴铵,静脉输注异丙酚,必要时吸入异氟醚维持麻醉.于切皮前、吻合冠状动脉前降支(LAD)、吻合右冠状动脉(RCA)、吻合左冠状动脉回旋支(LCX)和关胸时,记录S(-v)O2、CI和Hb,计算氧耗指数(VO2I)、氧供指数(DO2I)和氧摄取率(ERO2).于体位改变前即刻、头低位时、搬动心脏时和固定心脏后,记录S(-v)O2和CI.结果 各时点VO2I和Hb比较差异无统计学意义(P＞0.05);S(-v)O2、CI和ERO2于吻合RCA时降低,吻合LCX时降至最低,关胸时恢复至切皮前水平(P＜0.05);DO2I于吻合RCA和吻合LCX时降低,关胸时恢复至切皮前水平(P＜0.05).吻合RCA前和吻合LCX前,与体位变化前比较,头低位/头低右侧位时S(-v)O2升高(P＜0.05);与头低位/头低右侧位时比较,搬动心脏时S(-v)O2降低(P＜0.05);与搬动心脏比较,固定心脏后S(-v)O2升高(P＜0.05);各体位时CI差异无统计学意义(P＞0.05).结论 OPCABG术中病人体位、心脏位置瞬间改变和固定心脏时,S(-v)O2可实时、准确地反映CO的变化.     

非体外循环冠状动脉旁路移植术的血流动力学研究

目的：分析非体外循环冠状动脉旁路移植术中血流动力学的变化。方法：2000年6月至2001年1月，连续32例病人接受非体外循环冠状动脉旁路移植术，术中、术后对各吻合血管的血流动力学指标进行持续监测。全组完成前降支吻合32例、右冠状动脉26例、回旋支28例、对角支8例。结果：本组死亡例。行前降支冠状动脉吻合时血流动力学指标无明显变化。右冠状动脉吻合时影响右心功能。回旋支及对角支冠状动脉吻合时对血流动力学有明显的影响，导致平均肺动脉压（MPAP）、肺毛细血管楔压（PAWP）、中心静脉压（CVP）明显升高，每搏指数（SVI）及左室每搏功指数（LVSWI）有明显下降；心排指数（CI）有一定的下降趋势。行主动脉近心端吻合时尽管已无心脏搬动，但MPAP、SVRI及肺循环阻力指数（PVRI）仍较诱导后有明显升高，CI有明显下降。术毕及术的2、6、16h各血流动力学指标趋于正常，CI有明显改善。结论：非体外循环冠状动脉旁路移植行前降支及右冠状动脉吻合时对血流动力学影响较小，回旋支及对角支冠状动脉吻合时对血流动力学有明显的影响，术毕及术后2、6、16h各血流动力学指标趋于正常，心脏功能有明显改善。     

非体外循环冠状动脉旁路移植术对右心室血流动力学的影响

目的应用连续心排血量测定的方法,观察在进行非体外循环冠状动脉旁路移植术(OPCABG)中右心功能的变化. 方法冠状动脉粥硬化性心脏病178例,均为2～3支血管病变需行冠状动脉旁路移植术.术前心功能Ⅱ级72例,Ⅲ级84例,Ⅳ级22例.左心室射血分数0.35～0.82,平均搭桥数3.3根.所有病人均行Swan-Ganz漂浮导管,用连续心输出量监测仪连续监测血流动力学指标,包括心率(HR),平均动脉压(MAP),中心静脉压(CVP),平均肺动脉压(MPAP),右房压(RAP),肺毛细血管楔压(PCWP),心输出量(CO),心脏指数(CI),每搏容量指数(SVI),体循环阻力指数(SVRI),肺循环阻力指数(PVRI),混合静脉血饱和度(SvO2),右室射血分数(RVEF),右室收缩末容量(RVESV),右室舒张末容量(RVEDV),右室收缩末容量指数(RVESVI),右室舒张末容量指数(RVEDVI).设定时间点观察血流动力学指标:麻醉诱导后血流动力学稳定后,准备搬动心脏前(T1),吻合前降支前(T2),吻合回旋支或对角支前(T3),吻合右冠状动脉或后降支前(T4),心脏回位后,关胸前(T5).结果 4例死亡,其中2例为术前急性心肌梗死急诊手术,术后3天死于严重低心排血量综合征,1例术后7天死于严重呼吸衰竭,1例于术后4天死于急性肺栓塞.与T1相比,T2时,MPAP,PCWP,RAP和PVRI明显增加而SvO2明显降低;T3时,血流动力学变化明显,MPAP,PCWP,RAP和PVRI明显增加,SvO2明显降低,CI,SVI,RVEF明显下降,SVRI明显增加;T4时,HR,RAP明显增加而SvO2明显降低;T5时未恢复正常水平. 结论在进行纯缘支吻合时,右心功能有所下降,主要是CI及RVEF有明显的变化,而在前降支及右冠状动脉的吻合时,对右心血流动力学影响不大,因此,在OPCABG中监护右心功能具有重要意义,尤其是对右心功能受到损害的患者.     

不停跳冠状动脉旁路移植术中血流动力学的改变及处理

目的分析不停跳冠状动脉旁路移植（OPCAB）术中血流动力学变化特点,探讨维持血流动力学稳定的管理措施。方法2005年1月至8月连续100例病人接受OPCAB。共完成旁路血管313支,平均（3．1±0．7）支。术中监测每支冠脉远端吻合时的血流动力学指标,分析其变化特点。术中采取了心包悬吊、心脏位置改变、确保吻合口质量及合理应用血管活性药物等一系列管理措施,维持术中血流动力学稳定。结果前降支（LAD）远端吻合时,血流动力学变化较小。重建LAD血供后,平均动脉压（MAP）、左室运动指数（INSWI）、每搏输出指数（SI）、心排指数（CI）等指标升高。侧壁、下壁冠脉回旋支（LCX）、后降支（PDA）、左室后支（PLB）、钝缘支（OM）的远端吻合时,血流动力学波动大,心率（HR）、中心静脉压（CVP）明显升高,MAP、CI、右室舒张末容积（RVEDV）、LVSWI、右室做功指数（RVSWI）有明显下降。术毕CI明显改善。全组无死亡,除1例术中因血流动力学持续不稳定改为体外循环下手术和术后2例发生二次开胸止血外,无其他严重并发症,心绞痛缓解,心功能明显改善,均顺利出院。结论OPCAB术中,LAD远端吻合时血流动力学波动小,重建血供后,心肌收缩功能改善。侧壁、下壁冠脉远端吻合时血流动力学波动大。术中采用心包悬吊、心脏体位改变、保证吻合口质量及血管活性药物的合理应用等一系列措施是确保手术成功的关键。     

肺移植手术中中心静脉压、舒张末期容积指数及胸腔血容积指数与心脏指数的相关性研究

目的探讨在肺移植手术麻醉中CVP、舒张末期容积指数(global end-diastolic volume index,GEDI)、胸腔血容积指数(intrathoracic blood volume index,ITBI)与心脏指数(cardiac index,CI)的相关性,为临床应用提供参考。方法选择行肺移植手术的终末期肺病患者22例,麻醉诱导完成后于左侧股动脉穿刺置入脉搏指示连续心排血量(pulse index continuous cardiac output,PiCCO)专用带温度探头的压力监测管并连接监护仪,右颈内静脉或锁骨下静脉穿刺放置中心静脉导管监测CVP,同时右侧颈内静脉放置连续温度稀释Swan-Ganz导管,连续监测肺动脉压(pulmonary arterial pressure,PAP)、CI、GEDI及ITBI。分别记录麻醉后5 min双肺通气时(T_(0))、手术开始后20 min单肺通气时(T_(1))、肺动脉阻断10 min时(T_(2))、肺动脉开放后20 min时(T_(3))、恢复双肺通气20 min后(T_(4))和手术结束平卧位10 min后(T_(5))的MAP、心率、PAP、CVP、CI、GEDI及ITBI。对CVP、GEDI、ITBI与CI行相关性分析。结果各时间点的MAP和心率差异无统计学意义(P>0.05);与T_(0)时点比较,T_(3)、T_(4)、T_(5)时点PAP明显降低(P<0.05),T_(2)时点PAP明显高于其他各时点(P<0.05);T_(1)、T_(2)时点CVP明显高于其他时点(P<0.05);T_(2)时点CI与其他时间点比较明显降低(P<0.05);T_(2)时点GEDI及ITBL较T_(0)、T_(3)明显降低(P<0.05);其他各时点之间CVP、CI、GEDI及ITBL差异无统计学意义(P>0.05);T_(0)、T_(4)及T_(5)时点,CVP与CI呈正相关(P<0.05);T_(0)~T_(5)时点,GEDI、ITBI与CI呈正相关(P<0.05)结论在肺移植手术麻醉中,GEDI、ITBI与CI的相关性优于CVP。     

右美托咪定对非体外循环冠状动脉旁路移植术患者的影响

目的探讨右美托咪定在非体外循环冠状动脉旁路移植术(OPCABG)中对患者影响。方法择期行OPCABG患者60例,年龄50~65岁,ASAⅡ或Ⅲ级,BMI27kg/m2,采用随机数字表法均分为右美托咪定组(D组)和对照组(C组)。D组于麻醉诱导前,静脉输注右美托咪定负荷剂量1μg/kg,10min输注完成,然后以0.5~0.7μg·kg-1·h-1的速率静脉输注至术毕;C组以同样的方式给予等量的生理盐水。分别于入室后(T0)、药物输注10min(T1)、气管插管后(T2)、锯胸骨时(T3)、吻合前降支时(T4)、吻合左旋支或对角支时(T5)、吻合右冠状动脉或后降支时(T6)、血管吻合完毕后15min(T7)、术毕(T8)、术后6h(T9)、拔出气管导管后(T10)记录各项血流动力学指标。分别于T0、T3、T7、T8、T10时抽取桡动脉血1ml,测定血糖(Glu)浓度。于术前1d和术后7d采用简易精神状态量表和韦氏成人记忆及智力量表对患者进行术后认知功能测试。结果与T0时比较,C组T2~T4、T10时HR明显增快(P0.05);T2、T3、T10时MAP明显升高,而T5时MAP明显降低(P0.05);两组T5、T6时CVP、T8~T10时CI明显升高(P0.05),而T6时左、右心每搏作功指数(LVSWI、RVSWI)明显降低(P0.05);T3、T7、T8和T10时Glu浓度明显升高(P0.05)。与C组比较,D组T1~T10时HR明显减慢(P0.05),T1~T3、T5~T10时MAP,T1、T2、T4~T10时体循环阻力指数(SVRI),T1~T10时肺循环阻力指数(PVRI),T3、T7、T8时Glu浓度明显降低(P0.05)。C组POCD发生率为10例(33.3%),明显高于D组2例(6.7%)(P0.01)。结论静脉输注右美托咪定有利于稳定非体外循环冠状动脉旁路移植术患者围术期血流动力学,降低术后认知功能障碍的发生率。     

非体外循环冠状动脉旁路移植术的手术策略对术中血流动力学的影响

目的 研究非体外循环冠状动脉旁路移植术(CABG)的术中手术策略在吻合不同部位靶血管时对血流动力学的影响,探讨非体外循环CABG术中稳定血流动力学的措施.方法 2005年3月至2007年3月进行手术治疗的67例冠状动脉粥样硬化性心脏病患者,男性45例,女性22例,年龄44～81岁,均为严重三支病变.所有患者均先作左胸廓内动脉一前降支(LIMA-LAD)吻合,再作钝缘支(OM)及后降支(PDA)的序贯吻合.根据吻合的顺序不同将患者分为三组:组Ⅰ吻合顺序为PDA-OM-主动脉(Ao),共22例;组Ⅱ吻合顺序为Ao-PDA-OM,共14例;组Ⅲ为Ao-OM-PDA,共31例.以LIMA-LAD吻合前的血流动力学指标为基础值,在LAD吻合时及吻合后、PDA吻合时、OM吻合时各时间点测定血流动力学指标,并与基础值相比较.结果 67例患者均顺利施行了非体外循环CABG,无手术死亡.行LIMA-LAD吻合时,各项血流动力学指标变化不显著.LIMA-LAD完成后,各项指标显著改善.吻合OM时,组Ⅰ、组Ⅲ的心率(HR)、中心静脉压(CVP)显著升高(P＜0.05),平均动脉压(MAP)、心指数(CI)、左室做功指数(LVSWI)及右室做功指数(RVSWI)均显著降低(P＜0.05),但组Ⅱ上述指标变化均不显著(P＞0.05).吻合PDA时,组Ⅰ、组Ⅱ的HR、CVP均显著升高(P＜0.05),MAP、CI、LVSWI及RVSWI均显著降低(P＜0.05),但组Ⅲ上述指标变化不显著(P＞0.05).结论 先吻合桥血管的近端,再序贯吻合靶血管,这样的手术策略有利于非体外循环CABG时完成显露、吻合困难的OM、PDA部位的手术.     

Cardiopulmonary bypass recommendations in adults: the northern New England experience

Using a regional cardiopulmonary bypass (CPB) registry, we compared the practice of CPB at eight northern New England institutions to recently published recommendations. We examined CPB practice among 3597 adult patients undergoing isolated coronary artery bypass grafting surgery from January 2004 to June 2005. Registry variables were used to compare regional CPB practice to recommendations on topics of neurologic protection (pH management, avoidance of hyperthermia, minimizing return of pericardial suction blood, aortic assessment, arterial line filtration), maintenance of euglycemia, reduction of hemodilution, and attenuation of the inflammatory response. We report overall regional practice (regional minimum, maximum). All centers used alpha-stat pH management and arterial line filters. Avoidance of hyperthermia (temperature < 37degrees C) was achieved during 23.4% of procedures (regional minimum, 1.5%; maximum, 83.2%). Minimizing return of pericardial suction blood was achieved in 23.7% of cases (0.7%, 93.6%). Aortic assessment was performed during 45.7% of procedures (1.3%, 98.9%). Maintenance of euglycemia (< 200 mg/dL) was accomplished in 82.7% (57.1%, 97.9%) of cases. Hemodilution (hematocrit < 23% on CPB) was lower for men 32.4% (20.6%, 52.3%) than women 77.9% (64.7% 88.9%). Men were less likely to receive red blood cell transfusions in the operating room (11.0%; 1.8%, 20.9%) than women (54.6%; 30.1%, 70.6%). In an effort to attenuate the inflammatory response, surface coated circuits were used in 83.3% of procedures (8.8%, 100%). During this time, gaps existed between regional CPB practice and recently published recommendations. We continue to prospectively measure CPB practice relating to these recommendations to monitor and improve the care provided to our patients.     

Long-term evaluation of EC-IC bypass patency

Summary The EC-IC Bypass Study Group could not detect any benefit from surgery compared to medical management in the prevention of stroke in 1985 [15]. During the past years surgical revascularization was re-evaluated and considered as an appropriate treatment for a small subgroup of patients with recurrent focal cerebral ischaemia and impaired haemodynamics. This retrospective study examines the long-term benefit and patency rate of bypass.We present a follow-up of 5.6 years of 47 patients, all of whom underwent byupass surgery after 1985. Forty patients suffered recurring transient ischaemic attacks due to uni- or bilateral internal carotid artery occlusion. Examination included neurologic status, TCD with CO₂ or Diamox challenge, angiography, CT and SPECT scans.Neurological improvement was seen in 23% of patients with better results after early surgery, a worsening in 22% suffering further ischaemic events on a postoperative average of 2.8 years. Patency rate for vein graft material was 50%, for the STA-MCA procedure 91%. Occlusion of the vein graft occurred on an average after 1.4 years, other anastomosis after 2.7 years.We conclude that only few patients derived long-term benefit from EC-IC bypasses. Functioning of the bypass worsens over time, suggesting a role for surgery predominantly in the first year of ischaemic events due to insufficient collateral supply. Actual indications for bypass surgery may be patients with failure of maximal medical therapy and progressive ischaemia and haemodynamic compromise.     

Early results of off-pump coronary artery bypass

Objective: The purpose of this study is to compare the operative results of off-pump coronary artery bypass (OPCAB) and on-pump (conventional) coronary artery bypass (CCAB), to clarify qualitative problems and whether OPCAB is less invasive or not. Methods: OPCAB was consecutively performed in 63 patients and CCAB in 63 patients between July 1998 and December 2003. Results: The mean number of bypass grafts was 2.43 ±0.82 in the OPCAB group and 2.70±0.71 in the CCAB group (p=0.096). In-hospital mortality was 0% in the OPCAB group and 3.2% in the CCAB group. The incidence of perioperative myocardial infarction was 0% in the OPCAB group and 3.2% in the CCAB group. The incidence of postoperative major complications was significantly lower in the OPCAB group than in the CCAB group (OPCAB group=4 complications, CCAB group=13 complications). Cerebrovascular accidents occurred in 1.6% of patients in both groups. The incidence of sternal infection or mediastinitis was 0% in the OPCAB group and 3.2% in the CCAB group. The early patency rate of graft was 94.0% in the OPCAB group and 92.8% in the CCAB group, and was not significantly different (p=0.822). Conclusion: Operative mortality and major complications after surgery in OPCAB were lower than that in CCAB. The early patency rate in OPCAB was as good as that in CCAB. It is considered that OPCAB is less invasive and the quality of bypass in OPCAB is as good as that in CCAB.     

Perforated marginal ulcer after gastric bypass for obesity: a systematic review

Marginal ulcers are a recognized complication of gastric bypass procedures for obesity. Perforated marginal ulcer (PMU) is a life-threatening complication of marginal ulcers. We performed a systematic review to understand the presentation, management, and outcomes of PMUs. PubMed, Google Scholar, and Embase databases were searched to identify all studies on PMUs after gastric bypass procedures. A total of 610 patients were identified from 26 articles. The mean age was 39.8±2.59 years, and females represented most of the cohort (67%). The mean body mass index was 43.2±5.67 kg/m². Most of the patients had undergone a Roux-en-Y gastric bypass (98%). The time gap between the primary bariatric surgery and the diagnosis of PMU was 27.5±8.56 months. The most common presenting symptom was abdominal pain (99.5%) and a computed tomography scan was the diagnostic modality used in 72% of the patients. Only 15% of patients were on prophylactic proton pump inhibitors or H2 blockers at the time of perforation, and 41% of patients were smoking at the time. Twenty-three percent of patients were on nonsteroidal anti-inflammatory drugs. Laparoscopic omental patch repair of the perforation (59%) was the most used technique; 18% of patients underwent open surgery, and 20% were managed non-surgically. Thirty-day mortality was 0.97%; it was 1.21% (n=5) and 0% (n=0) in those who were managed surgically and nonsurgically, respectively. Ulcers recurred in 5% of patients. In conclusion, PMU is a surgical emergency after gastric bypass that can result in significant morbidity and even mortality. This is the first systematic review in scientific literature characterizing this condition.     

Infrageniculate thin-walled PTFE bypass: Preliminary study of 53 cases

Between May 1, 1983 and May 1, 1985, 53 patients whose mean age was 75 years, and who presented with rest pain or ischemic changes had infrageniculate insertion of femoropopliteal or femorotibial thin-walled polytetrafluoroethylene (PTFE-TW) bypasses. Occlusive atherosclerotic disease was present in all patients. Postoperative follow-up ranged from 6 to 30 months. One patient died in the immediate post-operative period whereas 15 others died later during follow-up. There was one case of prosthetic sepsis. No anastomotic aneurysms occurred. Actuarial analysis of overall patency rates in significant population samples showed that 88% and 68% of bypasses were functional at one month and two years, respectively. The overall rate of early amputation was 17%. Overall limb salvage was 67% at 30 months. In patients over 75, 85% of bypasses were patent at one year whereas life expectancy for one year in this same group of patients was 49%. Although this is a preliminary study, results obtained with this new material suggest that an average gain of 20% in patency rates can be expected compared to those recorded with standard PTFE prostheses. The PTFE-TW vascular prosthesis may be the material of first choice for the geriatric patient in order to promote early hospital discharge and return to the home environment. Even though long-term patency rates of venous grafts are better, we believe that the use of PTFE-TW prostheses in elderly patients with limited life expectancy may be preferred.     

Combined aortobifemoral and femoropopliteal bypass in the management of patients with extensive atherosclerosis

Certain patients have atherosclerosis in both aortoillac and femoropopliteal segments of the arterial tree and thus do not have a good result from reconstruction of the aortoiliac segment. No method has been developed to identify these patients and we do not know whether, by combining a femoropopliteal bypass with an aortobifemoral bypass, the results can be improved. We present a series of 153 patients with severe multilevel occlusive disease treated by simultaneous reconstruction and followed for up to 6.5 years. The cumulative patency of the femoropopliteal bypasses was 80% at four years. Functional and symptomatic improvement was excellent, and operative mortality was low when one considers the age and poor general condition of the patients.     

Unilateral iliac artery occlusive disease: A randomized multicenter trial examining direct revascularization versus crossover bypass

This randomized trial compared the patency of direct unilateral aorto- or iliofemoral prosthetic bypass with that of crossover femorofemoral or iliofemoral bypass in unilateral atheromatous occlusive disease of the iliac artery. Between May 1986 and March 1991, 143 patients were enrolled in this study (74 crossover and 69 direct revascularizations). Cardiovascular risk factors, preoperative symptoms, and atheromatous lesions were similar in both groups. Patients were followed by Duplex scanning with systolic pressure index measurements. Routine digital subtraction arteriograms were obtained postoperatively and separately, when hemodynamic anomalies developed. Mean follow-up was 22 months. One patient with direct revascularization died postoperatively. Primary patency of direct revascularizations was 89.8% at 48 months compared with 52% for crossover bypass. This difference was statistically significant. Secondary patency of direct and crossover revascularization at 48 months was 92.9% and 93.6%, respectively (not significant). Even though crossover bypasses seem attractive because of their technical simplicity and low morbidity, our results suggest that direct revascularizations are preferable in the young patient with no major operative risks, while crossover bypasses remain indicated in patients at risk.Presented at the Annual Meeting of the Société de Chirurgie Vasculaire de Langue Française, June 20–21 1991, Marseille, France.     

Methodologies,Devices, and New Surgical Concepts: Novel System for Percutaneous Cardiopulmonary Bypass

Percutaneous cardiopulmonary bypass (PCPB) has recently come to the forefront of medicine as a technique for resuscitating and supporting patients in various clinical situations. Current systems utilize small-diameter cannulas to aspirate blood under high suction into the cardiopulmonary bypass circuit. Aspiration-based systems have several disadvantages including risk of air embolism, blood hemolysis, and cavitation. Additionally, they are suboptimal for use during open-heart surgical procedures. A system with a venous cannula that employs gravity drainage has been evaluated. Once advanced into position over a guide- wire, the stylet is removed, causing the basket near the end of the cannula to expand. Blood flows into the cannula from side holes and the basket region, which prevents the vessel wall or atrium from collapsing around the catheter and impeding venous drainage. Hemodynamic, hematologic, and histologic examinations were performed on eight anesthetized mongrel dogs during 2 h of PCPB. All animals exhibited adequate tissue perfusion and right and left heart decompression. All animals were successfully weaned from PCPB and after 30 min exhibited normal myocardial function. No ischemic changes were observed in the heart, lung, kidney, or liver by light and electron microscopy. We conclude that full PCPB can be satisfactorily achieved by using a novel percutaneous venous cannula and gravity drainage     

Paracorporeal Artificial Heart in Postoperative Heart Failure

A pneumatically driven artificial heart with a tubular silicone rubber membrane and disc valves was used for functional heart replacement in the paracorporeal mode. A fluidic drive system allows adjustment of the heart rate, positive and negative pressures and systole/diastole ratio.
Since August, 1977, the artificial heart has been used in four patients with refractory postoperative heart failure not responding to volume loading, pH and electrolyte correction, catecholamines and intraaortic balloon pumping. Large cannulae were placed in the atria and great vessels. The ventricles were fixed on the chest paracorporeally. The assist system was used as a left heart bypass in one patient and as a biventricular bypass in three other patients. After 48–72 hours, the ventricular function recovered in three patients, permitting removal of the artificial heart. One patient died of cerebral complications six weeks later; the other two recovered completely and were released in good condition.
Profound postoperative heart failure can be completely reversed by the use of the paracorporeal artificial heart; the advantage of the system lies in the simplicity of its implantation and removal.     

Sequential bypass for multisegmental occlusive disease

We evaluated the effectiveness of a sequential bypass for multisegmental occlusive disease. Forty-seven multiple bypass grafts were performed on 43 patients ranging in age from 55 to 83 years (mean: 70 years). The indications for operation included incapacitating claudication in 20 limbs, resting pain in 15, and nonhealing ulcers in 12. An anatomical arterial bypass was performed on 36 limbs, consisting of an aorto-femoro-popliteal bypass in 21 limbs, a femoro-popliteal-posterior tibial bypass in 8, an ilio-femoro-popliteal bypass in 4, an ilio-femoro-posterior tibial bypass in 2, and a femoro-popliteal-plantar bypass in 1. Similarly, an extra-anatomical arterial bypass was performed on 11 limbs, consisting of an axillo-femoro-popliteal bypass in 6, a crossover femoro-femoro-popliteal bypass in 3, an axillo-femoro-posterior tibial bypass in 1, and a crossover femoro-femoro-anterior tibial bypass in 1. The follow-up period ranged from 3 to 77 months (mean: 23 months). Twelve graft failures occurred, and 2 of them required major amputations. The cumulative graft patency rate was 85% at one year and 65% at 3 years. Arterial Doppler examination revealed a mean preoperative ankle-brachial index of 0.29±0.25. The early and late mean postoperative ankle-brachial indices, however, increased to 0.97±0.19 and 0.84±0.25, respectively. Midterm results have indicated that such multiple sequential bypass grafts are effective.Presented at the 8th Congress Asian Surgical Association, Fukuoka, Japan, March 10–13, 1991