深低温停循环中不同脑灌注方式皮层超氧化物歧化酶、丙二醛及超微结构的变化

目的观察不同脑灌注方法对深低温停循环（DHCA）中脑皮质超氧化物歧化酶（SOD）、丙二醛（MDA）及超微结构的影响，比较不同灌注方式的脑保护效果。方法健康成年杂种犬15条，随机分为3组。Ⅰ组单纯行DHCA为对照，Ⅱ组DHCA＋逆行脑灌注（RCP），Ⅲ组DHCA＋选择性顺行脑灌注脑保护（SACP）。转流降温至鼻咽部温18℃时停循环90min，然后复温再灌注90min。结果停循环期皮层SOD活性下降而MDA含量上升，复温再灌注时变化更明显，各时间点差异有统计学意义（P〈0．05）。增加或下降程度以Ⅰ组最为明显，Ⅱ组次之，Ⅲ组最小。Ⅱ、Ⅲ组与Ⅰ组比较SOD、MDA变化明显减轻（P〈0．01），Ⅱ、Ⅲ组间亦差异有统计学意义（P〈0．05），与电镜观察结果一致。结论深低温停循环期间SACP有明显脑保护作用，RCP亦可减轻DHCA中脑损害。     

Comparative study of brain protection in ascending aorta replacement for acute type A aortic dissection: retrograde cerebral perfusion versus selective antegrade cerebral perfusion

Objectives

Postoperative disorders of the central nervous system remain a major problem in thoracic aortic surgery. Both retrograde cerebral perfusion and selective antegrade cerebral perfusion have become established techniques for cerebral circulatory management. In this study, we compared neurologic outcomes and mortality between retrograde cerebral perfusion and antegrade selective cerebral perfusion in patients with acute type A aortic dissection who underwent emergency ascending aorta replacement.

Methods

Between January 2003 and April 2011, a total of 203 patients with acute type A aortic dissection underwent emergency ascending aorta replacement in our hospital. We performed retrograde cerebral perfusion in 109 patients before 2006, and then mainly performed antegrade selective cerebral perfusion in 94 patients from 2006 onward.

Results

Cardiopulmonary bypass time and systemic circulatory arrest time were significantly longer in the antegrade selective cerebral perfusion group (p?=?0.04, p?<?0.001, respectively). The incidences of transient brain dysfunction and permanent brain dysfunction after surgery did not differ significantly between the groups. There were also no differences between the groups in other intraoperative variables, such as aortic cross-clamp time and the lowest rectal temperature, or in operative outcomes, including postoperative intensive-care-unit stay, mean peak amylase, and lipase levels until postoperative day 7, and 30-day mortality.

Conclusion

Both retrograde cerebral perfusion and antegrade selective cerebral perfusion were associated with acceptable levels of postoperative neurologic deficits, mortality, and morbidity. Either of these techniques for brain protection can be used selectively, based on a comprehensive assessment of general condition, in patients undergoing surgery for acute type A aortic dissection.     

Total arch replacement using antegrade selective cerebral perfusion with right axillary artery perfusion.

OBJECTIVE: Right axillary artery (AxA) perfusion, which can prevent cerebral embolism caused by retrograde perfusion via the femoral artery (FA), was used for selective cerebral perfusion (SCP) as well as cardiopulmonary bypass (CPB) in aortic arch repair. We review the outcome of aortic arch surgery using SCP with right AxA perfusion to clarify its efficacy. METHOD: Between 1998 and 2002, 120 patients underwent aortic arch repair using SCP with right AxA perfusion. The mean age was 69+/-10 years. Aneurysms were atherosclerotic in 79, dissecting in 32, and others in nine patients. Twenty of them (16.7%) required emergency surgery. CPB was initiated with right AxA and FA perfusion, and following SCP was established using right AxA and left common carotid artery perfusion. RESULTS: With right AxA perfusion, hospital mortality was 5.8%. Multivariate analysis showed only ruptured aneurysm was an independent determinant for hospital mortality. Permanent neurological dysfunction developed in one patient (0.8%), while seven (5.8%) suffered from temporary one. In univariate analysis, SCP time, stenosis of the carotid arteries, past history of cerebrovascular events, and atherosclerotic aneurysm were not related to temporary neurological deficits CONCLUSION: Right AxA perfusion in conjunction with SCP is a safe and useful alternative for brain protection in total arch replacement.     

Determination of cerebral blood flow dynamics during retrograde cerebral perfusion using power M-mode transcranial Doppler

BACKGROUND: Retrograde cerebral perfusion (RCP) during profound hypothermic circulatory arrest has been used as an adjunct for cerebral protection for repairs of the ascending and transverse aortic arch. Transcranial Doppler ultrasound has been used to monitor cerebral blood flow during RCP with varying success. The purpose of this study was to characterize cerebral blood flow dynamics during RCP using a new mode of monitoring known as transcranial power motion-mode (M-mode) Doppler ultrasound. METHODS: Data on pump-flow characteristics and patient outcomes were collected prospectively for patients undergoing ascending and transverse aortic arch repair. Retrograde cerebral perfusion during profound hypothermic circulatory arrest was used for all operations. Intraoperative cerebral blood flow dynamics were monitored and recorded using transcranial power M-mode Doppler ultrasound. RESULTS: Between August 2001 and March 2002, we used transcranial power M-mode Doppler ultrasound monitoring for 40 ascending and transverse aortic arch repairs during RCP. Mean RCP time was 32.2 +/- 13.8 minutes. Mean RCP pump flow and RCP peak pressure for identification of cerebral blood flow were 0.66 +/- 0.11 L/min and 31.8 +/- 9.7 mm Hg, respectively. Retrograde cerebral blood flow during RCP was detected in 97.5% of cases (39 of 40 patients) with a mean transcranial power M-mode Doppler ultrasound flow velocity of 15.5 +/- 12.3 cm/s. In the study group, 30-day mortality was 10.0% (4 of 40 patients). The incidence of stroke was 7.6% (3 of 40 patients); the incidence of temporary neurologic deficit was 35.0% (14 of 40 patients). CONCLUSIONS: Transcranial power M-mode Doppler ultrasound consistently demonstrated retrograde middle cerebral artery blood flow during RCP. Transcranial power M-mode Doppler ultrasound can provide optimal RCP with individualized settings of pump flow.     

Assessment of arteriovenous blood flow during retrograde cerebral perfusion

OBJECTIVE: This study examined arterial and venous blood flow during retrograde cerebral perfusion (RCP) to quantify what proportion of arterial inflow is not recovered as venous outflow. DESIGN: Prospective. SETTING: Community hospital, university setting, single institution. PARTICIPANTS: Twelve patients undergoing reconstructive aortic arch surgery with profound hypothermic circulatory arrest and RCP. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: RCP arterial inflow and venous outflow measurements were recorded at 2-minute intervals for 10 minutes, averaged, and then compared. Only 44.9%+/-16.3% of RCP inflow returned through the aortic arch. The remainder was not recovered. CONCLUSION: Internal jugular venous valves, sequestration, and shunting may contribute to arterial inflow diversion during RCP.     

Arch repair with unilateral antegrade cerebral perfusion.

OBJECTIVE: Several antegrade cerebral perfusion techniques with differing neurological outcomes are employed for aortic arch repair. This study demonstrates the clinical results of aortic arch repair with unilateral cerebral perfusion via the right brachial artery. METHODS: Between January 1996 and March 2004, 181 patients underwent aortic arch repair via the right upper brachial artery with the use of low-flow (8-10 ml/kg per min) antegrade selective cerebral perfusion under moderate hypothermia (26 degrees C). Mean patient age was 58+/-12 years. Presenting pathologies were Stanford type A aortic dissection in 112, aneurysm of ascending and arch of aorta in 67, and isolated arch aneurysm in two patients. Ascending and/or partial arch replacement was performed in 90 patients and ascending and total arch replacement in 91 patients (including 27 with elephant trunk). In a subset of patients, renal and hepatic effects of ischemic insult were assessed. Free hemoglobin and lactate dehydrogenase levels were measured pre and postoperatively to identify hemolytic effects of brachial artery cannulation. RESULTS: Mean antegrade cerebral perfusion time was 36+/-27 min. Three patients with acute proximal dissection died due to cerebral complications. One patient had transient right hemiparesis. Total major neurological event rate was 2.2%. Brachial artery was able to carry full cardiopulmonary bypass flow with mild hemolysis. Renal and hepatic tests showed no deleterious effects of limited ischemia at moderate hypothermia. CONCLUSIONS: Arch repair with antegrade cerebral perfusion through right brachial artery has excellent neurological results, provides technical simplicity and optimal repair without time restraints, does not necessitate deep hypothermia and requires shorter CPB and operation times.     

Brain protection using antegrade selective cerebral perfusion: a multicenter study

BACKGROUND: To evaluate the results of antegrade selective cerebral perfusion as a method of brain protection during surgery of the thoracic aorta and to determine predictors of hospital mortality and adverse neurologic outcome. METHODS: Between October 1995 and March 2002, 588 patients underwent aortic surgery with the aid of antegrade selective cerebral perfusion. There were 334 men (56.8%); the mean age was 63.7 +/- 11.8 years. One hundred sixty-two patients (27.6%) underwent urgent operation. The separated graft technique was employed to reimplant the arch vessels in 230 patients (65.3%) of the 352 requiring aortic arch replacement. Associated procedures were performed in 254 patients (43.2%). One hundred twelve patients underwent elephant trunk procedure. The mean cerebral perfusion time was 67 +/- 37 minutes. RESULTS: The overall hospital mortality rate was 8.7%. A logistic regression analysis revealed urgent operation, recent central neurologic event, tamponade, unplanned coronary artery revascularization and pump time to be independent predictors of hospital mortality (p < 0.05). The permanent neurologic dysfunction rate was 3.8%. A logistic regression analysis showed tamponade to be independent predictor of permanent neurologic dysfunction (p < 0.05). The transient neurologic dysfunction rate was 5.6%. Recent central neurologic event, tamponade, coronary disease, and aortic valve replacement were indicated as independent predictors of transient neurologic dysfunction by logistic regression (p < 0.05). CONCLUSIONS: In our experience the utilization of antegrade selective cerebral perfusion resulted in encouraging results in terms of hospital mortality and brain complications. Neither the extent of the replacement nor the duration of the cerebral perfusion had an impact on hospital mortality and neurologic outcome.     

Pig heart preservation with antegrade intracellular crystalloid versus antegrade/retrograde miniplegia

Both histidine-tryptophan-ketoglutarate (HTK) solution and Braile miniplegia are commercially available and used with high success. The objective of this work was to compare the effects of both strategies in an animal model. Twelve pigs were divided into control, HTK, or Braile groups using a model of controlled global cardiac ischemia/reperfusion under cardiopulmonary bypass with 1 hour heart ischemia followed by 2 hour reperfusion. No significant differences were found over time or between groups for heart rate, arrhythmia, number of defibrillations required, blood gases, myocardial lactate production, myocardial oxygen consumption, nor coronary flow index. The Braile strategy was associated with a lower 120 minute postreperfusion coronary vascular resistance with higher water content, leukocyte infiltration, and oxidative damage compared with controls. Drainage of HTK solution to the venous return was followed by higher potassium and lower sodium blood concentrations. One-hour heart preservation with HTK or Braile systems followed by 2 hour reperfusion both allow for acceptable preservation of the healthy pig myocardium. Maneuvers such as leukocyte filtration or hemofiltration may further improve these conditions.     

Effective cerebral protection using near-infrared spectroscopy monitoring with antegrade cerebral perfusion during aortic surgery

Abstract Objective: Antegrade cerebral perfusion (ACP) under moderate hypothermia may improve cerebral protection. Intraoperative measurement of cerebral regional oxygen saturations (rSO2) using near‐infrared spectroscopy (NIRS) can provide accurate monitoring of cerebral perfusion during ACP. We evaluated the role, outcomes, and advantages of using NIRS in providing effective cerebral protection with ACP. Methods: Between May 2006 and March 2009, 27 patients (mean age 60%, 93% elective) underwent ascending aorta replacement with ACP monitored by NIRS. ACP was established through the right axillary artery (n = 26). All patients had continuous intraoperative measurement of both anterior cerebral rSO2 using NIRS (INVOS; Somanetics Corporation, Troy, MI, USA). Posterior cerebral perfusion was measured using left radial artery pressures. Quality of life (QoL) was assessed using a Short Form 36 questionnaire. Results: Mean cardiopulmonary bypass and aortic cross clamp time were 169 ± 27 and 95 ± 22 minutes, respectively. Mean ACP rate of 1.27 ± 0.35 L/min provided a mean left radial artery pressure of at least 60 mmHg. All patients’ cerebral rSO2 were maintained above their baseline using NIRS. Mean ACP time was 14.3 ± 2.6 minutes at a mean core temperature of 23.4 °C ± 2.0 °C. Temporary neurological deficit was observed in two patients (7.4%). No permanent neurological dysfunction was observed. Thirty‐day mortality was 3.7%. At median follow‐up of 18.3 (interquartile range 10.8 to 23.3) months survival was 92% and mean norm‐based QoL score was above average at 52.5 ± 6.5. Conclusion: Cerebral rSO2 and left radial artery pressure monitoring with ACP during aortic surgery provides accurate measurement of cerebral perfusion resulting in minimal neurological and perioperative complications and good midterm QoL outcomes.     

The optimal flow rate for antegrade cerebral perfusion during deep hypothermic circulatory arrest

The aim of this study is to compare cerebral protection using antegrade cerebral perfusion (ACP) with various flow rates during deep hypothermic circulatory arrest (DHCA) in a piglet model. Twenty‐three piglets were randomized to five groups: the control group (n = 3), DHCA group (n = 5), ACP25 group (n = 5), ACP50 group (n = 5), and ACP80 group (n = 5). Three control piglets did not undergo operations. Twenty piglets underwent cardiopulmonary bypass (CPB) and DHCA for 60 min at 20°C. ACP was conducted at 0, 25, 50, and 80 mL/kg/min in the DHCA, ACP25, ACP50, and ACP80 group, respectively. Serum S‐100B protein and neuron‐specific enolase were monitored, and brain tissues were assayed for the activities of caspase‐3 and stained for the evidence of apoptotic cellular injury. Rise in serum S‐100B level (post‐CPB—pre‐CPB) in the ACP50 group was significantly lower than that in the ACP80 group (P = 0.001). Caspase‐3 levels were significantly elevated in the ACP80 group compared with the ACP25 (P = 0.041) and ACP50 group (P = 0.01), while positive terminal deoxyneucleotidyl transferase‐mediated biotin‐dUTP nick end labeling reaction scores in the ACP80 group were significantly higher than those in the ACP25 (P = 0.043) and ACP50 group (P = 0.023). Cerebral protection effects of ACP at 25 and 50 mL/kg/min were superior to that of ACP at 80 mL/kg/min as determined by cerebral markers, immunology, and histology.     

The methodologies of hypothermic circulatory arrest and of antegrade and retrograde cerebral perfusion for aortic arch surgery

In spite of recent advances in thoracic aortic surgery, postoperative neurological injury still remains the main cause of mortality and morbidity after aortic arch operation. The use of cardiopulmonary bypass (CPB) and hypothermic circulatory arrest, temporary interruption of brain circulation, transient cerebral hypoperfusion, and manipulations on the frequently atheromatic aorta all produce neurological damages. The basic established techniques and perfusion strategies during aortic arch replacement number three: hypothermic circulatory arrest (HCA), antegrade cerebral perfusion (ACP), and retrograde cerebral perfusion (RCP). During the past decade and after several experimental studies, RCP lost its previous place in the armamentarium of brain protection, giving it up to ACP as a major method of brain perfusion during HCA. HCA should be applied at a temperature of asymptotically equal to 20 degrees C with long-lasting cooling and rewarming and should not exceed by itself the time of 20-25 min. RCP does not seem to prolong safe brain-ischemia time beyond 30 min, but it appears to enhance cerebral hypothermia by its massive concentration inside the brain vein sinuses. HCA combined with ACP, however, could prolong safe brain-ischemia time up to 80 min. Cold ACP at 10 degrees -13 degrees C should be initially applied through the right subclavian or axillary artery and continued bihemispherically through the left common carotid artery at first and later the anastomosed graft, with a mean perfusion pressure of 40-70 mm Hg. The safety of temporary perfusion is being confirmed by the meticulous monitoring of brain perfusion through internal jugular bulb O2 saturation, electroencephalogram, and transcranial comparative Doppler velocity of the middle cerebral arteries.     

Total arch replacement using a 4-branched graft with antegrade cerebral perfusion

Objective

Total arch replacement (TAR) is an established standard surgical procedure. We report >1000 cases of TAR using a 4-branched graft with antegrade cerebral perfusion (ACP) during a 15-year period.