414例胸主动脉瘤手术的体外循环经验

目的　回顾性总结不同体外循环方法在 414例胸主动脉瘤手术中的应用及特殊情况的处理。方法　升主动脉瘤组 2 90例 ,中低温全心肺转流是基本方法 ;其中夹层动脉瘤 2 2 2例 ,74例累及弓部 ,为实施脑保护 ,将此类病人分为 4个亚组 :深低温停循环组 (DHCA)、深低温停循环辅以上腔静脉逆行灌注组 (DHCA +RCP)、应急重建脑灌注组、上下分离灌注组 ;共有 5 6例采用RCP脑保护。 12 4例降主动脉瘤均采用左心转流。 1例术中发生意外室颤不能复苏而改为全心肺转流。结果　升主动脉瘤组中 ,15例DHCA 10～ 6 3min ,平均 35 86min ;RCP 5 6例 ,平均 42 4min ;最长达 81min ;死亡率 3 79% (11 2 90例 )。降主动脉瘤组左心转流平均时间 (12 5 5 6± 5 7 2 8)min ;死亡率 6 6 5 % (7 12 4例 ) ;3例术后并发下肢截瘫。结论　胸主动脉瘤手术的体外循环方法应依病变部位、手术入路有所不同 ,术中保护重要器官免受缺血损伤是关键所在。DHCA加RCP是重建主动脉弓手术时较好的脑保护方法。     

深低温停循环经右锁骨下动脉持续脑灌注与经上腔静脉逆行脑灌注的比较

目的比较深低温停循环(DHCA)时经右锁骨下动脉持续脑灌注(RSA)和经上腔静脉逆行脑灌注(SVC)对脑组织的保护效果。方法将36只杂种猫随机分为6组(n=6)建立体外循环(CPB)。1组DHCA45min,无脑灌注;2组DHCA45min,经上腔静脉逆行脑灌注;3组DHCA45min,经右锁骨下动脉持续脑灌注;4组DHCA90min,无脑灌注;5组DHCA90min,经上腔静脉逆行脑灌注;6组DHCA90min,经右锁骨下动脉持续脑灌注。检测各组脑组织超微结构、颈静脉血乳酸含量、脑组织ATP含量和一氧化氮合成酶(NOS)活性。结果DHCA时间相同时,SVC组和RSA组脑组织光镜及电镜下缺血、缺氧改变明显轻于无脑灌注组,颈静脉血乳酸含量和脑组织NOS活性均显著低于无脑灌注组(P<0.05),脑组织ATP含量显著高于无脑灌注组(P<0.05)。DHCA45min后,SVC组和RSA组比较各指标差异无统计学意义。DHCA90min后,RSA组脑组织超微结构缺血、缺氧改变轻于SVC组。且RSA组脑组织ATP含量[(2.02±0.19)μmol/g]显著高于SVC组[(1.72±0.21)μmol/g,P<0.05]。结论长时间深低温停循环时经右锁骨下动脉持续脑灌注比经上腔静脉逆行脑灌注更有利于保护脑组织的氧供需平衡。     

四分支人工血管置换术治疗主动脉弓部疾病

目的总结应用深低温停循环(DHCA)、顺行选择性脑灌注(ASCP)四分支人工血管置换术治疗主动脉弓部疾病的方法和经验。方法2004年9~12月,日本群马心血管病中心心血管外科应用四分支人工血管置换治疗主动脉弓部疾病12例,其中主动脉瘤7例(4例为升主动脉瘤累及主动脉弓部、3例为主动脉峡部瘤),主动脉夹层动脉瘤5例(DeBakey型1例、DeBakey型3例、DeBakey型1例)。在深低温停循环下应用球囊灌注管对3个头臂动脉行选择性脑灌注,用四分支人工血管行主动脉弓置换;其中Bentall手术加主动脉弓部/右半弓置换各1例,全弓部置换3例,右半弓置换3例,弓降部置换4例;12例手术中2例行象鼻手术。结果全组12例患者恢复良好,无脑部及其它系统并发症发生。手术时间5.5±1.7h,术中深低温停循环时间42.2±12.9min;术中4例未输血;术后住院时间22.3±7.2d。结论顺行选择性脑灌注对脑保护安全可靠,应用四分支人工血管置换术治疗主动脉弓部疾病可缩短深低温停循环的时间,降低弓部置换手术的复杂程度。     

大鼠两种不同供肝对原位肝移植术中和术后影响的比较

目的　比较正常 (HB)和心跳停搏 (NHB)供肝对大鼠原位肝移植术中和术后的影响。方法　雄性SD大鼠随机分成HB和NHB两组 ;NHB组又分别设心跳停搏 30min(HNB - 30 )和 4 5min(NHB - 4 5 )两组。每组各行原位肝移植 5 0、30和 30次。结果　HB和NHB组冷缺血、无肝期、肝下下腔静脉 (IVC)阻断、受体手术时间分别为 (6 9.76± 1.5 2 )min和 (70 .32± 1.5 3)min、(16 .4 6± 0 .96 )min和(16 .4 0± 0 .73)min、(2 2 .5 6± 1.73)min和 (2 2 .75± 1.16 )min、(89.38± 3.75 )min和 (90 .5 8± 3.76 )min ;术后受体苏醒和主动饮水时间分别为 (5 .4 3± 3.88)min和 (5 4 .0 6± 5 .99)min、(43.0 4± 10 .19)min和(12 6 .79± 15 .0 2 )min ;受体术后鼻粘膜出血率分别为 4 .17%和 92 .6 8% ;受体第 1周体重下降幅度分别为 (6 .15± 1.92 ) %和 (9.6 2± 1.80 ) % ;第 2周体重增加幅度分别为 (7.4 4± 2 .5 9) %和 (3.16± 1.0 4 ) %。HB组近期死因分别为原发性移植肝无功能 (PGF)、麻醉过深、肺部感染和肝上下腔静脉 (SVC)吻合口漏 ;而NHB组分别为PNF、麻醉过深、无肝期较长 (>17min)和再灌注后供肝渗血 ;HB和NHB - 30、NHB - 4 5组术后 1周存活率分别为 90 %、5 0 %和 30 %。结论　NHB较HB术中操作更复杂 ,更需     

非体外循环下行双向格林手术(附58例报道)

目的　总结非体外循环下行双向格林手术的体会。方法　 2 0 0 0年 5月至 2 0 0 1年 9月 ,在非体外循环下行双向格林手术 5 8例。年龄 (3 5 4± 1 5 9)岁 ,体重 (13 6± 4 0 )kg。上腔静脉与右心耳插管临时转流 ,自上腔静脉入右房处横断上腔静脉 ,缝闭近心端 ,应用可吸收线端侧吻合远心端与右肺动脉 ,前壁用自体心包片加宽。结果　全组无手术死亡 ,术后并发乳糜胸 4例 ,一过性昏迷 1例。腔静脉阻断 (48± 15 )min ,术前氧饱和度 0 75± 0 0 9,肺动脉压 (12 8± 2 3)mmHg(1mmHg=0 133kPa) ;术毕氧饱和度 0 93± 0 0 5 ,肺动脉压 (16 5± 2 9)mmHg,胸腔及心包引流液 (145± 10 3)ml,呼吸机辅助 (13± 7)h ,住院 (10± 5 )d。结论　非体外循环下行双向格林手术是一种安全、可靠的术式。对于难以解剖根治或一期生理矫治的肺血少的复杂先天性心脏病 ,该术式是一种良好的手术方法。     

腺苷停搏液对未成熟心肌的保护作用

目的　探讨腺苷加入停搏液对未成熟心肌的保护作用。方法　 0～ 2d的豚鼠 3 0只 ,随机分为 3组 ,每组 10只。低温组 :局部单纯低温 (15～ 17℃ ) ;Thomas组 :ThomasⅡ号停搏液灌注加低温 ;腺苷组 :腺苷高钾停搏液灌注加低温。平均全心停循环 90min ,再灌注 3 0min。观察诱导心脏停搏时间、冠脉流量恢复率 (CFR)、心肌含水量、超微结构、丙二醛 (MDA )和黄嘌呤氧化酶(XO)的变化。结果　腺苷组诱导心脏停搏时间 (4 .0± 1.1)s较Thomas组 (15 .6± 3 .7)s明显缩短 ;心肌MDA含量 (5 5 .2 6± 3 .3 4)低于Thomas组 (61.49± 3 .70 )和低温组 (64 .92± 3 .2 0 ) ;再灌注末心肌含水量 (77.17± 1.44 ) %少于Thomas组 (79.5 4± 2 .49) %和低温组 (79.48± 1.78) % ;CFR(73 .72± 6.74)高于Thomas组 (67.85± 4.83 )和低温组 (63 .5 5± 4.70 ) ;心肌超微结构改变较轻。 3组间心肌XO差异无显著性 (P >0 .0 5 )。结论　腺苷加入停搏液中对未成熟心肌有保护作用。     

幼猪深低温体外循环最适区域性脑灌注流量的实验研究

目的探索幼猪在深低温体外循环中的最适区域性脑灌注（RCP）流量,为先天性心脏病（先心病）小儿患者术中脑保护策略提供理论基础。方法20只健康幼猪,年龄23．7±2．1d,体重6．4±0．6kg,采用随机数字表法分为4组,每组各5例。对照组为单纯深低温停循环（DHCA组）;实验组按不同RCP流量分为3组：RCP25组,流量为25．9±3．0ml（kg·min）;RCP50组,流量为49．7士1．8ml／（kg·rain）;RCP80组,流量为79．5±0．9ml／（kg·min）;通过检测血浆中建立CPB前（T1）、DHCA或RCP前（T2）、RCP结束后10min（T3）、停机前（T4）、CPB结束后1h（Ts）以及2h（T5）6个时间点检测血浆中的S-100β蛋白、神经元特异性烯醇化酶（NSE）的浓度、脑氧摄取率（CEOz）及大脑皮质半胱天冬氨酸酶3（caspase3）的含量,评估不同RCP流量的脑保护效果。结果各组幼猪血浆中S-100β蛋白和NSE的浓度于T4时明显升高,并于T5时达到高峰（P〈0．05）;RCP50组血浆中S-100β蛋白和NSE的浓度从T4时开始明显低于DHCA组和RCP80组（P〈O．05）,与RCP2。组相比,其差异无统计学意义（P〉0．05）。各组CEO2在T1时差异无统计学意义（P〉0．05）,在T2时明显降低（P％0．05）。DHCA组、RCPzs组和RCP50组的CEO2在T3时开始升高,RCP20组在T3时稍微下降,但其差异无统计学意义（P〉0．05）;从T4开始,RCP25组和RCPj。组的CEO。与DHcA组和RCP80组更接近于基础值（T1）（P〈0．05）。大脑皮质中caspase3的含量在3种不同流量的RCP组明显低于DHCA组（F=23．54,P〈0．01）,其中RCP25组及RCP5。组明显低于RCP80组（F=23．54,P〈0．01）,而RCP2s组与RCP50组的caspase3含量差异无统计学意义（P〉0．05）。结论在我们建立的幼猪深低温体外循环模型中,RCP最适灌注流量为25～50ml／（kg·rain）,并且趋向于50ml／（kg·rain）。     

肿瘤坏死因子α介导骨骼肌缺血-再灌注损伤的实验研究

目的研究肿瘤坏死因子α(TNF α)介导骨骼肌缺血 再灌注损伤的作用机制。方法2 4只健康雄性SD大鼠 (2 5 0～ 30 0g)随机分成 3组。对照组 :仅行麻醉及颈外静脉插管术 ;损伤组 :左后肢缺血 4h ,再灌注 4h ;治疗组 :缺血 4h ,再灌注 4h ,再灌注即刻经静脉导管给与抗TNF α单克隆抗体。结果损伤组较对照组单核细胞TNF αmRNA转录增加 ,血浆丙二醛 (MDA) (9 9± 1 8)比(5 5± 0 4 )、肌酸激酶 (CK) (12 2± 2 4 )比 (49± 11)、一氧化氮 (NO) (2 70± 98)比 (12 8± 4 6 )、组织过氧化物酶 (MPO) (骨骼肌 4 2 7± 0 5 3)比 (1 2 8± 0 19,肺 2 6 1± 0 12 )比 (0 5 7± 0 0 2 )显著升高 (P <0 0 1) ,骨骼肌和肺组织超微结构发生病理改变。治疗组较损伤组MDA(6 2± 1 2 )比 (9 9± 1 8)、CK(5 8±12 )比 (12 2± 2 4 )、NO(15 4± 5 5 )比 (2 70± 98)、MPO(骨骼肌 2 13± 0 2 1)比 (4 2 7± 0 5 3肺 0 95± 0 0 1)比(2 6 1± 0 12 )水平明显降低 (P <0 0 5 ) ,骨骼肌和肺组织病理损伤减轻。结论骨骼肌缺血 再灌注激发TNF α的生成 ,在介导骨骼肌和肺的损伤中起重要作用     

右锁骨下动脉插管体外循环技术的临床应用

目的　探讨右锁骨下动脉插管体外循环技术在临床应用的价值。方法　在深低温、停循环时应用右锁骨下动脉插管的选择性脑灌注技术 ,手术治疗 70例累及主动脉弓的心血管疾病病人。结果　全组体外循环时间 5 2～ 32 8min ,平均 (12 9 18± 46 78)min ,脑部低流量灌注时间最长达 81min ,平均(2 8 0 6± 2 1 0 7)min ,术后病人 6h内全部清醒 ,无神经系统并发症。结论　停循环期间 ,采用右锁骨下动脉插管的选择性脑灌注方法进行脑保护简便、安全、有效。     

大鼠心跳停搏供肝在原位肝移植术中损伤的预防

目的：探讨预防和减轻大鼠心跳停搏供肝在原位肝移植术中的损伤，以提高手术成功率。方法：雄性SD大鼠随机分为心跳停搏热缺血30min(N-30)和45min(N-45)两组;，每组分别行原位肝移植术30只次。同时，根据是否对供体手术方法进行改进又分为常规组和改良组。结果：(1)常规组和改良组的冷缺血时间分别为(70.04±1.48)和(70.36±1.42)min(P>0.05)，无肝期均为(16.40±0.73)min，肝下下腔静脉阻断时间均为(22.75±1.16)min，受体手术时间均为(90.58±3.76)min。(2)N-30和N-45常规组分别有5和9只受体术后死于原发性移植肝无功能，而改良组仅为1和2只(40%∶12%,P<0.05);(3)N-30和N-45组因术中分别出现供肝损伤致再灌注后供肝大量渗血、无肝期过长、切除受体肝脏时麻醉过深，而各有5和7，2和1，2和2只受体术后死亡。(4)N-30和N-45组术后1周存活率分别为50%和30%(P<0.05)。结论：预防心跳停搏供肝游离时损伤、供肝再灌注后渗血、无肝期过长和切除受体肝脏时麻醉过深是大鼠心跳停搏供肝原位肝移植手术成功的关键。     

Clinical application of retrograde cerebral perfusion for brain protection during surgery of ascending aortic aneurysm--a report of 50 cases

This study was designed to discuss the effects on the brain by different protective methods in ascending aortic aneurysm surgery retrospectively. Two hundred seventy-one surgeries of ascending aortic aneurysm have been done in the past 15 years. There were 65 patients with a dissecting aneurysm of the aortic arch or right arch. To protect the brain, deep hypothermic circulatory arrest (DHCA) combined with retrograde cerebral perfusion (RCP) through superior vena cava (N = 50) and simple DHCA (N = 15) were used during the procedure. Blood samples for lactic acid level from the jugular vein were compared in both groups. Perfusion blood distribution and oxygen content difference between the perfused blood and returned blood were measured in 5 and 10 of RCP patients, respectively. The DHCA time was 35.86 +/- 18.81 min (10 approximately 63 min) and DHCA + RCP time was 45.5 +/- 17.21 min (16 approximately 81 min). The resuscitation time was 7.11 +/- 1.59 h (4.4 - 9.4 h) in DHCA versus 5.43 +/- 2.15 h (2 approximately 9 h) in RCP patients. The operation death rate was 3/15 in DHCA group and 1/50 in RCP patients. Central nervous complication occurred in 3/12 of DHCA patients and 1/49 of RCP patients (p < .01). The overall survival rate was 96% (RCP) versus 67% (DHCA); the central nervous system dysfunction was 20% in DHCA versus 2% in RCP (p < .001). The blood lactic acid level increased significantly after reperfusion in DHCA than that in RCP. The measurement of blood distribution indicated that approximately 2Q% of the perfused blood returned from arch vessels. The difference of oxygen content between perfused and returned blood showed that the oxygen uptake was adequate in RCP group. The application of RCP can prolong the safety duration of circulation arrest. Continuous cerebral perfusion may maintain the brain at a cooler temperature and flush out particulate and air emboli while open anastomosis of the aortic arch to the prosthesis can be safely performed. Therefore, RCP is a preferable method for brain protection in our clinical practices.     

Neurologic outcome after surgery of the aortic arch: Comparison of deep hypothermic arrest,antegrade and retrograde cerebral perfusion

Introduction Neurologic deficits are still a major complication of aortic arch surgery. We therefore compared cerebral protection by deep hypothermic circulatory arrest (DHCA), antegrade (ACP) and retrograde (RCP) cerebral perfusion. Patients and Method 64 consecutive patients who underwent replacement of the aortic arch for aneurysms or dissections from January 1999 through August 2001 were analysed retrospectively for clinical and neurologic outcome. For DHCA core temperature was lowered to 18°C and was kept between 18 and 24°C in the perfused groups. Selective antegrade cerebral perfusion (ACP) was achieved either via the subclavian artery or the brachiocephalic trunc. Retrograde cerebral perfusion (RCP) was performed via the superior vena cava. Results Indication for surgery was type A acute dissection or ruptured aneurysm in 39 patients, chronic dissection and aneurysm without rupture in 25 patients. Operative procedure was partial arch replacement in 46 patients and total arch replacement in 18 patients. For cerebral protection retrograde cerebral perfusion (RCP) was used in 22 Patients (23±11 min.), ACP in 30 patients (25±19 min.) and DHCA in 14 patients (23±13 min.). Mortality was 17% (11 of 64 patients: ACP 7, RCP 2 and DHCA 2). Neurologic deficits occured in 5%, without differences for groups. Conclusion For this patient cohort, needing comparatively short times for aortic arch reconstruction, a low neurologic complication rate without significant differences for the method of cerebral perfusion was observed.     

Cardiopulmonary bypass for thoracic aortic aneurysm: a report on 488 cases

Our objective was to investigate different cardiopulmonary bypass (CPB) techniques for thoracic aortic aneurysm retrospectively. Four hundred and eighty-eight patients with thoracic aortic aneurysm received surgical treatment. Total CPB was used routinely in 331 cases with ascending aortic aneurysm. When the aneurysm expanded to the aortic arch, brain protection was executed by adopting deep hypothermia circulatory arrest (DHCA) or DHCA combined with retrograde cerebral perfusion (RCP). Selected cerebral perfusion via carotid artery was used in three cases and separated upper and lower body perfusion in five cases. Left heart bypass was adopted for the surgeries of 157 cases with descending aortic aneurysm. In two of the cases, ventricular defibrillation could not be achieved, and then bypass was altered to separated upper and lower body perfusion to acquire satisfactory outcome. In the ascending aortic aneurysm group, DHCA time in the 17 patients was 10-63 minutes (mean 35.58 +/- 18.81 min), and DHCA +/- RCP time in 61 patients was 16-81 minutes (mean 43.43 +/- 17.91 min). Total mortality of aortic aneurysm surgery requiring full CPB was 5.4% (18/331), in which eight patients died in emergency operations. The total mortality of emergency operation was 11.9% (8/67). In the descending aortic aneurysm group, time of left heart bypass was 125.56 +/- 57.28 min, and the total mortality was 7% (11 of 157 patients). Three patients developed postoperative paraplegia. Techniques for extracorporeal circulation for surgery of the aorta are dependent on the nature of the disease and require a flexible approach to meet the specific anatomical challenge. The ability to alter the perfusion circuit to meet unexpected situations should be anticipated and planned for. In this series, we have varied our approach to perfusion techniques as required with acceptable outcome data as compared to the international literature.     

Direct visualization of minimal cerebral capillary flow during retrograde cerebral perfusion: an intravital fluorescence microscopy study in pigs

BACKGROUND: Retrograde cerebral perfusion (RCP) is used in some centers during aortic arch surgery for brain protection during hypothermic circulatory arrest. It is still unclear however whether RCP provides adequate microcirculatory blood flow at a capillary level. We used intravital microscopy to directly visualize the cerebral capillary blood flow in a piglet model of RCP. METHODS: Twelve pigs (weight 9.7 +/- 0.9 kg) were divided into two groups (n = 6 each): deep hypothermic circulatory arrest (DHCA) and RCP. After the creation of a window over the parietal cerebral cortex, pigs underwent 10 minutes of normothermic bypass and 40 minutes of cooling to 15 degrees C on cardiopulmonary bypass ([CPB] pH-stat, hemocrit 30%, pump flow 100 mL x kg(-1) x min(-1)). This was followed by 45 minutes of DHCA and rewarming on CPB to 37 degrees C. In the RCP group the brain was retrogradely perfused (pump flow 30 mL x kg(-1) x min(-1)) during DHCA through the superior vena cava after inferior vena cava occlusion. Plasma was labeled with fluorescein-isothiocyanate-dextran for assessing microvascular diameter and functional capillary density (FCD), defined as total length of erythrocyte-perfused capillaries per observation area. Cerebral tissue oxygenation was determined by nicotinamide adenine dinucleotide hydrogen (NADH) autofluorescence, which increases during tissue ischemia. RESULTS: During normothermic and hypothermic antegrade cerebral perfusion the FCD did not significantly change from base line (97% +/- 14% and 96% +/- 12%, respectively). During retrograde cerebral perfusion the FCD decreased highly significantly to 2% +/- 2% of base line values (p < 0.001). Thus there was no evidence of significant capillary blood flow during retrograde cerebral perfusion. The microvascular diameter of cerebral arterioles that were slowly perfused significantly decreased to 27% +/- 6% of base line levels during RCP. NADH fluorescence progressively and significantly increased during RCP, indicating poorer tissue oxygenation. At the end of retrograde cerebral perfusion there was macroscopic evidence of significant brain edema. CONCLUSIONS: RCP does not provide adequate cerebral capillary blood flow and does not prevent cerebral ischemia. Prolonged RCP induces brain edema. However, there might be a role for a short period of RCP to remove air and debris from the cerebral circulation after DHCA because retrograde flow could be detected in cerebral arterioles.     

Two different techniques of retrograde cerebral perfusion for thoracic aortic surgery through a left thoracotomy

The authors used profound hypothermic circulatory arrest and continuous retrograde cerebral perfusion for aortic surgery that involved the distal arch through a left thoracotomy. For the first seven patients, oxygenated blood from cardiopulmonary bypass was perfused retrogradely through a venous cannula positioned into the right atrium. In the last 11 cases, venous blood, provided by a perfusion from the lower body, was circulated passively in the brain with the descending aorta clamped. The period of profound hypothermic circulatory arrest was 34.6 +/- 11.1 min, and continuous retrograde cerebral perfusion was 31.3 +/- 11.1 min. Seventeen patients survived, but there was one early death. Two patients with a severely atherosclerotic aneurysm developed permanent neurological dysfunction. The combination of profound hypothermic circulatory arrest, continuous retrograde cerebral perfusion and open aortic anastomosis through a left thoracotomy protects the brain adequately, and facilitates evacuation of debris and air in the aortic arch. It produces satisfactory results for aortic surgery that involves the distal arch.     

Perioperative outcome in adults undergoing elective deep hypothermic circulatory arrest with retrograde cerebral perfusion in proximal aortic arch repair: evaluation of protocol-based care

OBJECTIVE: The purpose of this study was to describe perioperative outcome in adults undergoing elective proximal aortic arch repair with protocol-based deep hypothermic circulatory arrest (DHCA) with retrograde cerebral perfusion (RCP). DESIGN: Retrospective and observational. SETTING: Cardiothoracic operating rooms and intensive care unit. PARTICIPANTS: Seventy-nine consecutive adults undergoing elective proximal aortic arch repair with DHCA (1999-2001). INTERVENTIONS: None. MAIN RESULTS: Average age of the patients was 64.9 years. Mean circulatory arrest time was 30.4 +/- 8.5 minutes. Perioperative mortality was 7.6%. Perioperative stroke incidence was 3.8%. Tracheal extubation was successful in 87.3% of patients within 24 hours of operation. Of the cohort, 80.8% were discharged from the intensive care unit within 72 hours of surgery. Median length of hospital stay was 7.4 days. Repeat mediastinal exploration because of bleeding occurred in 3.8% of patients. Although perioperative renal dysfunction (defined as >1.5-fold increase in plasma creatinine concentration) developed in 24.0% of patients, only 3.8% required dialysis. CONCLUSIONS: The above parameters establish a baseline incidence for major perioperative complications in adults undergoing elective DHCA with RCP for elective proximal aortic arch repair. In approaching the open aortic arch for short periods of circulatory arrest, deep hypothermia with adjunctive RCP is safe and effective.     

升主动脉和弓部动脉瘤的外科治疗

目的：总结升主动脉和弓部动脉瘤手术治疗经验，以期进一步提高手术疗效。方法：自2000年7月至2002年5月应用深低温停循环（DHCA）和上腔静脉逆行脑灌注（RCP）技术手术治疗升主动脉和弓部动脉瘤20例，其中急症手术5例。施行全弓置换术2例，全弓置换和象鼻手术3例，半弓置换术15例。同期行Bentall手术8例，升主动脉置换术或同时行主动脉瓣置换术12例，冠状动脉旁路移植术1例。结果：术后早期死亡1例，短时间浅昏迷1例，呼吸功能不全2例，肾功能不全2例，无晚期死亡。结论：DHCA和RCP技术是手术治疗升主动脉和弓部瘤的安全、有效方法，急性A型夹层动脉瘤的手术方式取决于内膜破裂口的位置；正确掌握DHCA和RCP技术，手术方式和手术技术、围术期处理是提高手术疗效的关键因素。     

主动脉弓部手术75例

目的 总结主动脉弓部手术的方法和临床经验。方法75例弓部手术中74例采用深低温停循环（DHcA）技术，其中54例脑保护采用上腔静脉逆灌（RCP），20例采用右腋动脉顺灌（SCP）；仅1例在中度低温体外循环下行局部切除吻合。升主动脉和半弓置换53例，其中同期行降主动脉腔内支架植入术11例，弓部内膜破口修补6例，降主动脉近端内膜破口修补3例；升主动脉和全弓置换20例，其中同期行传统象鼻手术12例，降主动脉腔内支架植入4例；单纯弓部瘤切除缝合及弓部置换各1例。同期手术包括17例Bentall手术，12例AVR，3例Cabrol手术，5例二尖瓣成形术，9例主动脉瓣悬吊成形术等。DHCA9～120min，平均42．3min。结果手术死亡5例，死亡率6．7％。主要并发症为呼吸功能不全11例，肾功能不全7例，一过性精神异常9例。结论DHCA＋RCP及DHCA＋SCP技术均是主动脉弓部手术的有效方法，但后者更适用于复杂的弓部手术；手术范围和方式取决于病变性质和范围，术前状况和手术技术是影响手术效果的决定因素。     

Retrograde cerebral perfusion versus selective cerebral perfusion as evaluated by cerebral oxygen saturation during aortic arch reconstruction.

BACKGROUND: Time limits for neuroprotection by retrograde cerebral perfusion (RCP) and selective cerebral perfusion (SCP) in aortic arch aneurysm repair or dissection are undergoing definition. METHODS: Using near-infrared optical spectroscopy, changes in regional cerebrovascular oxygen saturation (rSO2) were compared between the two perfusion methods. RESULTS: Immediately before cardiopulmonary bypass, baseline rSO2 was 63.9%+/-6.9% for the RCP and 66.1%+/-5.3% for the SCP group (no significant difference). As patients were core-cooled to 20 degrees C, rSO2 increased to 73.1%+/-8.8% and 74.1%+/-7.9% in the RCP and SCP groups, respectively. With circulatory arrest, rSO2 suddenly decreased. After starting cerebral perfusion, rSO2 returned to prearrest values in the SCP group but continued decreasing steadily in the RCP group, to levels below baseline after about 25 minutes. At the end of perfusion, rSO2 was 57.4%+/-12.2% for the RCP group and 71.7%+/-6.9% for the SCP group, and the ratio of rSO2 to baseline value was 0.89 for RCP and 1.08 for SCP despite a shorter brain perfusion time for RCP (38.8+/-18.0 versus 103.3+/-43.3 minutes). Three of 5 patients whose ratios of rSO2 to baseline at the end of brain protection were 0.7 or less had neurologic deficits. CONCLUSIONS: Although SCP showed no clinically important time limitation, rSO2 continued to decrease with time during RCP. An rSO2 ratio less than 0.7 could represent a critical lower limit.     

Aortic arch replacement with proximal first technique.

BACKGROUND: Deep hypothermic circulatory arrest (DHCA) without retrograde cerebral perfusion (RCP) has a strict time limit. We modified a surgical technique for anastomosis to shorten the period of DHCA and unilateral cerebral perfusion (UCP). METHODS: Between March 1993 and August 2001, retrospective analysis was done on 23 consecutive patients, who underwent aortic arch replacement with branches. The patients were divided into two groups: DHCA group and UCP group. The DHCA group, in which DHCA alone and without additional cerebral perfusion was performed, comprised of nine patients. Proximal aortic anastomosis was performed first during systemic cooling; then both the brachiocephalic artery and left carotid artery were reconstructed with the branches of the artificial graft during circulatory arrest; thereafter, cerebral and coronary perfusions were resumed. The UCP group, in which DHCA was not used but right hemisphere perfusion during deep hypothermia was performed when the origin of brachiocephalic artery was safely clamped, consisted of 14 patients. RESULTS: Mean time of DHCA was 18.8+/-4.2 minutes and that of right hemisphere perfusion time was 11.0+/-3.8 minutes, respectively. Twenty-one patients survived the surgery (91.3%), and two (8.7%) died during hospitalization. Transient cerebral complication occurred in four patients in the DHCA group and all recovered. Logistic regression analysis revealed that DHCA was the only parameter to significantly influence temporary neurological dysfunction. There was no other significant difference between the two groups. CONCLUSION: With our modified and simple surgical technique for aortic arch repair, we were able to successfully shorten the DHCA time and right hemisphere perfusion time. However, because DHCA was the only parameter to significantly influence temporary neurological dysfunction, some form of continuous cerebral perfusion at deep hypothermia may be a safer method to preserve cerebral function.