Safety of Hypothermic Circulatory Arrest During Unilateral Antegrade Cerebral Perfusion for Aortic Arch Surgery

BackgroundHypothermic circulatory arrest (HCA) with adjunctive unilateral antegrade cerebral perfusion (UACP) is widely used as a cerebral protection strategy during aortic arch surgery. However, the ideal temperature for HCA during UACP remains unknown. The study compared clinical outcomes of patients in different temperature groups for HCA during UACP.MethodsFrom January 2009 to January 2016, 1691 patients who underwent aortic arch surgery for HCA during UACP in Beijing Anzhen Hospital were categorized into 2 groups according to nasopharyngeal temperature before initiating systemic circulatory arrest: the low temperature group (≤ 24°C, 22.9°C; 22.0°C-23.5°C; n = 1207) and the high temperature group (24.1°C-28.0°C, 24.6°C; 24.3°C-24.9°C; n = 484). After balancing the differences of baseline conditions by propensity score matching, 473 pairs of patients were matched, and the prognosis was compared with matched patients.ResultsThe multivariable Cox regression analysis shows the high temperature group was an independent predictor for 30-day mortality (hazard ratio [HR], 0.55; 95% confidence interval [CI], 0.33-0.93; P = 0.03). After matching, the high temperature group was still an independent predictor of 30-day mortality (HR, 0.55; 95% CI, 0.32-0.98; P = 0.04). In subgroup analyses, there was an interaction between the high temperature group and UACP > 40 minutes for 30-day mortality (P _{for interaction}< 0.05). The high temperature group had a significant protective effect in the UACP ≤ 40 minutes subgroup (HR, 0.30; 95% CI, 0.12-0.74; P = 0.01) but not in the UACP > 40 minutes subgroup (HR, 1.00; 95% CI, 0.46-2.20; P = 0.99).ConclusionsThis study shows that the high temperature (24.1°C-28.0°C) management strategy for HCA during UACP is safer for UACP ≤ 40 minutes. High temperature benefits were not found in patients for UACP > 40 minutes.     

中度低温停循环结合选择性脑灌注在婴儿主动脉弓部手术中的应用

目的 总结中度低温停循环(moderate hypothermia circulatory arrest,MHCA)结合选择性顺行脑灌注(sective antegrade cerebral perfusion,SACP)技术在婴儿主动脉弓重建手术中的应用经验.方法 回顾性分析上海市儿童医院心胸外科于2012年1月至2018年12月间完成的主动脉弓病变合并心内畸形矫正的患儿50例.依据中心温度将患儿分为深低温停循环(deep hypothermia circulatory arrest,DHCA)组及MHCA组,每组25例.所有患儿均在体外循环(cardiopulmonary bypass,CPB)下行一期手术治疗.主动脉弓重建过程中采用低温停循环技术,通过无名动脉SACP(25~40 ml·kg^-1·min^-1)的CPB管理方法.心肌保护采用康斯特器官保护液(HTK液).记录两组患者的一般资料及术中、术后指标.结果 两组均无与CPB相关的神经系统并发症.两组患儿年龄、体重、病种、术前肝肾功能及术前左心室射血分数值比较差异均无统计学意义(P>0.05).CPB时间MHCA组较DHCA组明显缩短[(120.00±22.60)min比(137.40±22.88)min,P=0.019];术后24 h胸腔引流量及正性肌力药物评分MHCA组较DHCA组明显减少,分别为[(49.84±20.66)ml比(78.20±52.31)ml,P=0.03;(9.72±2.47)分比(12.24±3.07)分,P=0.004].结论 在婴儿主动脉弓重建手术中,采用DHCA或MHCA结合SACP的技术均能均减少术后神经系统并发症发生,不增加术后其他并发症.MHCA可减少CPB时间、术后胸腔引流量及术后血管活性药物的使用量.     

深低温停循环逆行脑灌注与选择性顺行脑灌注脑组织自由基变化的实验研究

目的:研究深低温停循环(DHCA)两种不同脑灌注方法下脑组织的自由基变化情况。方法:健康成年犬15只,随机分为3组。单纯DHCA组(n=5),DHCA+逆行脑灌注(RCP)组(n=5),DHCA+顺行脑灌注(SCP)组(n=5)。各组分别于停循环前、停循环30 min、停循环60 min、停循环90 min、复温再灌注30min 5个时间点各取少量脑组织检测自由基指标丙二醛(MDA)、超氧化物歧化酶(SOD)的含量并进行比较。各组于停循环90 min分别留取少量脑皮质,备作透射电镜观察脑组织超微结构,重点观察线粒体的改变。结果:单纯DHCA组随时间的推移超氧化物歧化酶活力明显下降,丙二醛含量明显上升,各时间点及复温再灌注30 min同停循环前比较有显著性差异(P<0．05-0．01);DHCA+SCP组除复温再灌注30 min外各时间点两种指标的改变均不明显(P>0．05)。DHCA+RCP组、DHCA+SCP组与单纯DHCA组在停循环60 min、停循环90 min、复温再灌注30 min 3个时间点比较超氧化物歧化酶、丙二醛均有极显著差异(P<0．01～0．001);其中在停循环90 min、复温再灌注30 min 2个时间点DHCA+RCP组与。DHCA+SCP组比较有显著差异(P<0．05-0．01)。在停循环90 min时,单纯DHCA组脑皮质神经细胞超微结构破坏显著,线粒体数量减少,肿胀变性,线粒体嵴消失;DHCA+RCP组开始出现超微结构破坏,但较单纯DHCA组程度轻;DHCA+SCP组脑组织超微结构仍基本正常。结论:①RCP、SCP均可维持DHCA时脑血流的供应,清除自由基,减轻脑损伤。②DHCA期间应用SCP符合生理情况,清除自由基效果更好。     

Deep Hypothermic Circulatory Arrest: Real-Life Suspended Animation

Deep hypothermic circulatory arrest (DHCA) is a cerebral protection technique that was developed in the 1950s and popularized in the 1970s. It has become one of the three most common cerebral protection techniques currently used in aortic arch surgeries, with the other two being antegrade cerebral perfusion (ACP) and retrograde cerebral perfusion (RCP). At our institution, DHCA has been the cerebral protection technique of choice for over a quarter century. Our clinical experience with DHCA has been very positive, and our clinical studies have shown DHCA to have outcomes equal to (and sometimes better than) those of ACP and RCP, and DHCA to be very effective at preserving neurocognitive function. Other institutions, however, prefer ACP or RCP to DHCA. Each technique has its own set of pros and cons, and the question regarding which technique is the superior method for cerebral protection is hotly debated.     

深低温停循环下全主动脉弓置换术后急性肾损伤的危险因素

目的回顾性分析深低温停循环下全主动脉弓置换术患者的临床资料,探索全主动脉弓置换术后急性肾损伤的围术期危险因素。方法通过分析我院2012年6月至2013年6月期间,深低温停循环下行全主动脉弓置换术患者的临床数据,使用RIFLE标准定义急性肾损伤及其损伤程度,将患者分为非急件肾损伤组（肾功能止常组）和急性肾损伤组（包括风险期、损伤期、衰竭期）,比较两组患者闻术期各项临床指标,计算患者深低温停循环下令主动脉弓置换术后急性肾损伤的发生率,并通过Logistir回归分析找出急性肾损伤的围术期危险因素．结果共入选130例患者,男性94例（723％）,年龄（488±10．0）岁。术后有67例（51．5％）的患者处于损伤期或衰竭期,其中共17例（131％）患者行术后血液透析治疗。多因素Logislic回归分析结果显示：患者年龄（OR=1．055,95％ CI=1．003-1．110,P=0．039）、术前诊断为手动脉夹层（OR=21．770,95％CI=1．888-251．050,P=0014）及刚术期红细胞输入总量（OR=1.108,95％CI=1．002-1．225,P=0046）是全主动脉弓置换术后发牛急性肾损伤的独立危险因素。结论深低温停循环下行全主动脉弓置换术后急性肾损伤的发生率较高,其中需要临床干预的发牛率为51．5％（包括损伤期和衰竭期）。患者年龄、术前诊断为主动脉夹层及围术期红细胞输入总量是全主动脉弓置换术后发生急性肾损伤的独立危险因素。     

不同温度停循环的脑损伤评估及机制研究

目的深低温停循环(deep hypothermic circulatory arrest,DHCA)应用于主动脉弓和复杂先心病手术,停循环为手术提供无血视野,降温到一定程度以保护脏器。DHCA术后神经系统并发症较高,而不同程度的低温停循环对脑造成的影响与机制目前还未完全明确。方法 20只SD大鼠随机分为4组:深低温停循环组(15-20℃)、中低温停循环组(20-25℃)、浅低温停循环组(25-30℃)和假手术组,术后收集血样、脑组织,并分离海马组织。HE染色后评估神经元损伤情况。免疫组化观察各组HIF-1α的表达与分布。Elisa法测定血浆S100β浓度。Western blot检测各组海马组织凋亡相关蛋白Casepase3、Bax和Bcl-2表达量。结果 HE染色观察3组低温停循环组海马CA1区均有损伤表现,但组间无明显差异。HIF-1α阳性表达率、Casepase3、Bax和Bcl-2表达量,以及血浆S100β组间均无统计学差异。结论不同程度的低温后停循环带来大鼠脑组织损伤,但严重程度并不和温度呈线性关系,这表明低温对脑组织缺血再灌注损伤的影响有着较为复杂的机制。     

血脑屏障与深低温停循环脑损伤

血脑屏障是机体维持中枢神经系统内环境稳定的结构基础,在深低温停循环脑损伤过程中起着重要作用。深入探讨血脑屏障的结构基础和功能、在深低温停循环脑损伤过程中的变化以及对血脑屏障通透性调节的可能机制为深低温停循环脑损伤的防治提供了一个全新的思路。     

计算机体层摄影术灌注成像研究超早期脑梗死患者脑血流动力学状态

目的通过观察超早期脑梗死区域计算机体层摄影术灌注成像变化,分析超早期脑梗死区域脑血流动力学状态及影响因素。方法选择17例突发偏瘫或失语、发病时间少于6 h、计算机体层摄影术常规扫描阴性的患者,立即行灌注成像检查。分析灌注成像相关数据,并且与20例正常人群进行比较。结果6 h内脑梗死患者患侧灰质及白质脑血流量、脑血流容积明显低于对侧,差异有显著性(均P<0.05);脑梗死组对侧与对照组比较,灰质区域的脑血流量下降、脑血流容积上升、达峰时间上升,白质区域的脑血流量上升、达峰时间上升,差异有显著性(P<0.05);发病年龄与病灶侧脑血流动力学状态呈显著性相关(脑血流量r=-0.707、脑血流容积r=-0.658)(P<0.05)。结论超早期脑梗死患者计算机体层摄影术灌注成像不仅有病灶侧大脑血流动力学改变,而且还有对侧大脑血流动力学改变;患者年龄也是影响病灶侧大脑血流动力学状态相关因素之一。     

低温停循环选择性脑灌注在婴幼儿主动脉弓缩窄Ⅰ期根治手术中的应用

目的:总结低温停循环(HCA)结合选择性脑灌注(ASCP)技术在婴幼儿主动脉弓缩窄合并心内畸形手术中体外循环方法。方法:回顾性分析北京安贞医院2009年1月至2010年8月22例婴幼儿主动脉弓缩窄合并心内畸形,行一期主动脉弓重建患者的临床资料。患者年龄平均13个月(16 d～8岁),体质量3～22 kg,平均(7.2±3.1)kg。全部病例温度均降至鼻咽温22.5℃～26.4℃,直肠温度降至24℃～28℃,在手术中所有患者采用HCA,通过无名动脉进行ASCP(20～30 mL/kg)的体外循环方法。心肌保护均采用一次性低温康斯特器官保护液(HTK液)。所有患者均采用术中常规超滤(CUF)及术后改良超滤(MUF)。结果:所有患者均无与体外循环相关的神经系统并发症,无死亡。体外循环时间65～170 min,平均(135±20)min,主动脉阻断时间16～95 min,平均(62±14)min,ASCP时间10～50 min,平均(28±8)min,自动复跳率100%。患儿术后常规镇静,清醒时间6～90 h,平均(44±22)h,机械通气时间8～96h,平均(47.5±20)h,ICU滞留时间1～11 d,平均(4.9±2.5)d,住院时间10～58d,平均(30±11.4)d。结论:在婴幼儿主动脉弓缩窄合并心内畸形主动脉弓重建手术中,应用低温停循环选择性脑灌注的体外循环方法,对于患儿重要器官的保护是安全可行的。     

Diffusion and Perfusion MRI in Acute Cerebral Ischemia

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Cerebral perfusion in relation to cognitive function and type 2 diabetes

AIM/HYPOTHESIS: Underlying mechanisms for decreased cognitive functioning in patients with type 2 diabetes are unclear. In the general population, cerebral hypoperfusion is a risk factor for cognitive dysfunction and dementia. Reduced cerebral perfusion may account for cognitive impairments in diabetic patients relative to controls. METHODS: A total of 98 patients with type 2 diabetes and 47 control participants underwent neuropsychological evaluation. Total cerebral blood flow (CBF) was assessed non-invasively by measuring the volume flow in the internal carotid arteries and basilar artery with two-dimensional phase-contrast magnetic resonance angiography. Relative total CBF, a measure of mean total cerebral perfusion, was obtained by expressing total CBF per 100 ml brain parenchyma volume. RESULTS: Patients with type 2 diabetes performed worse on neuropsychological tests (p < 0.05). Total CBF per 100 ml brain parenchyma volume did not differ between participants with and without diabetes (difference -2.3 ml min(-1) 100 ml(-1); 95% CI -6.0, 1.3). In the entire group, total CBF per 100 ml brain parenchyma volume was positively associated with cognitive functioning (0.09 SD increase in composite z score per 10 ml min(-1) 100 ml(-1) increase in relative total CBF). This association was not affected by type 2 diabetes. CONCLUSIONS/INTERPRETATION: Although total CBF per 100 ml brain parenchyma volume was associated with cognitive functioning, it did not explain cognitive impairments in patients with type 2 diabetes relative to controls.     

Hypothermic Fibrillatory Arrest During Coronary Artery Bypass Grafting in a Man With Calcified Aorta and Ventricular Fibrillation

A 67-year-old man undergoing coronary artery bypass grafting had aortic calcification that prohibited aortic cross-clamping. When ventricular fibrillation developed during surgery, we instituted hypothermic fibrillatory arrest to avoid aortic cross-clamping. In addition to our patient''s case, we discuss the advantages and disadvantages of using hypothermic fibrillatory arrest during cardiac surgery.     

Low and Moderate Doses of Ethanol Produce Distinct Patterns of Cerebral Metabolic Changes in Rats

The quantitative autoradiographic 2-[¹⁴C]deoxyglucose method was used to measure the effects of the acute administration of ethanol on local rates of glucose utilization in male Sprague-Dawley rats. Rates of glucose utilization were measured 10 min after the intraperitoneal administration of 0.00, 0.25, 0.50, and 1.00 g/kg ethanol. The acute administration of the lowest dose of ethanol (0.25 g/kg) significantly increased rates of cerebral metabolism, as compared with vehicle-treated controls, in structures of the mesocorticolimbic and nigrostriatal dopaminergic systems. Among the affected regions were the nucleus accumbens, medial prefrontal cortex, olfactory tubercle, caudate, ventral tegmental area, and substantia nigra. Acute administration of 0.50 g/kg ethanol resulted in similar trends in increased functional activity; however, significant increases were limited to the somatosensory cortex, posterior nucleus accumbens, and the CA3 region of the hippocampus. In contrast, the administration of 1.00 g/kg ethanol produced widespread decreases in rates of glucose utilization in brain regions involved in processing of sensory and motor information, as well as in portions of the limbic system. These data indicate that the effects of acute ethanol administration on functional activity as reflected by rates of glucose utilization are dose-dependent. These cerebral metabolic effects parallel the dose-dependent effects of ethanol on motor behavior, with stimulatory effects generally observed at lower doses and depressive effects at higher doses. Moreover, each of the doses studied produced alterations in functional activity in a unique subset of structures. This suggests that different neuroanatomical circuits mediate the effects of each dose.