Objective To investigate the clinical effects and the brain protection effect of different cardiopulmonary bypass in treating descending aortic aneurysms. Methods From January 2001 to December 2008, 65 patients were diagnosed to have descending aortic aneurysm with magnetic resonance imaging (MRI) in our hospital. Among them, there were 56 males and 9 females whose age was between 15 and 71 years old with an average of 48.1 years. The disease process ranged from 6 days to 4 months (19.0±6.5 d ). Preoperative diagnosis showed that there were 41 cases of DeBakey type Ⅲinterlayer, 9 cases of Marfan syndrome with postoperative complications of type Ⅲ interlayer, 7 cases of pseudoaneurysm and 8 cases of true aneurysm. We adopted artificial blood vessel repair patch to repair the damaged point of the descending aorta in 2 cases, performed vascular aneurysm resection and artificial vessel replacement on 63 patients, and carried out descending aorta replacement and intercostal artery grafting in 18 cases. Results Among the 65 cases of cardiopulmonary bypass patients, there were 13 cases of left heart bypass, 12 cases of heart bypass, 30 cases of deep hypothermic circulatory arrest (DHCA) with total body retrograde perfusion (TBRP) and 10 cases of modified separate perfusion of upper and low body. Cardiopulmonary bypass time, DHCA time, retrograde perfusion time, upper body circulatory arrest time and low body circulatory arrest time were respectively 51-212 min, 18-75min, 18-73 min, 21-31 min, and 39-67 min. No death occurred during the operation, and there were no brain complications or complications of paralysis among all the patients. Two patients died after operation because of renal failure. Conclusion Good results can be achieved by selecting different method of cardiopulmonary bypass based on the anatomical location and range of the thoracic descending aortic aneurysms. The selection criteria should be favorable to the surgical operation and organ protection.
Deep hypothermic circulatory arrest (DHCA) technology is the basic means of organ protection in complex aortic arch surgeries, congenital heart disease surgeries, pulmonary endarterectomy and other operations. The establishment of DHCA in rat model is helpful to explore the influence of DHCA and its pathophysiological pathways. However, there are some problems in this process, such as imperfect monitoring, inaccurate management and non-standard heparinization during the experimental period. It is necessary to review relevant literatures on DHCA rat model, in order to establish a DHCA rat model with standardized operation, clear standards and mature technology.
Deep hypothermic circulatory arrest (DHCA) is an important assistant technique for complex cardiac surgery, which creates convenient operating conditions for surgery, and is also one of the measures to protect the brain during operation. However, the complications caused by this technique cannot be ignored, and it should be noticed that the occurrence of intestinal injury is relatively insidious, but brings great pain to patients and significantly reduces the quality of life after operation. Studies have shown that intestinal ischemia-reperfusion injury is induced by DHCA. It causes mast cells to activate and release many inflammatory mediators that destroy the intestinal mucosal epithelium barrier, and eventually lead to intestinal injury. This article reviewed the research progress of mast cells in the mechanism of DHCA-induced intestinal injury.
Abstract： Objective To investigate the cerebral protective effects of hyperoxia management during deep hypothermia circulatory arrest（DHCA） rabbit by the blood gas indexes, superoxide dismutase（ SOD） activity and malondialdehyde （MDA） levels of brain, and ratio of water to brain. Methods A DHCA and antegrade selective cerebral perfusion （ASCP） rabbit model was established. Twenty-four 11-13 week-old male New Zealand rabbits（ weighing 2.7 to 3.4 kg） were assigned to three groups with a random number table: a sham operation group （Sham group）, an ASCP group （S group）, and an ASCP ＋ hyperoxia management group （SH group）. There were eight rabbits in each group. We recorded the intraoperative values for arterial oxygen pressure （PaO2）, arterial oxygen saturation （SaO2）, jugular venous oxygen pressure（PjvO2）, jugular venous oxygen saturation（ SjvO2） and blood lactate level. The brain SOD activity, MDA levels, and ratio of water to brain were measured after the operation. Results Before initiating circulatory arrest, before initiating reperfusion and five minutes of reperfusion, levels of PaO2 , PjvO2 , and SjvO2 in the SH group were significantly higher than those of the S group and Sham group. SOD activity in the SH group was not significantly different from that of the S group[（213.53±33.52） U/mg. prot vs. （193.02±27.67） U/mg. prot] and Sham group[（213.53±33.52） U/mg. prot vs.（244.38±35.02）U/mg. prot], but the SOD activity in the S group was lower than that in the Sham group（ P ＜ 0.05）. MDA levels in the SH group were lower than that in the S group[（1.42±0.30） nmol/mg. prot vs. （2.37±0.55） nmol/mg. prot, P ＜ 0.05]. Conclusion Our data show that hyperoxia management during DHCA＋ASCP improves rabbits’PjvO2 and SjvO2, maintains brain SOD activity, and decreases brain MDA levels, demonstrating the neuroprotective effects of hyperoxia mangagement.
Objective To determine risk factors of delayed recovery of consciousness after aortic arch surgery underdeep hypothermic circulatory arrest （DHCA） and antegrade selective cerebral perfusion （ASCP）. Methods We retrospectively analyzed clinical data of 113 patients who underwent aortic arch surgery under DHCA＋ASCP in the Affiliated Drum Tower Hospital， Medical School of Nanjing University from October 2004 to April 2012. According to whether they regained consciousness within 24 hours after surgery， all the 113 patients were divided into normal group （73 patients including 55 males and 18 females with their average age of 48.1±10.9 years） and delayed recovery group （40 patients including 29 males and 11 females with their average age of 52.2±11.4 years）. Risk factors of delayed recovery of consciousness after surgery were evaluated by univariate analysis and multivariate logistic regression analysis. Results Nine patients （8.0%） died postoperatively， including 5 patients with multi-organ failure， 2 patients with heart failure， 1 patient with mediastinal infection， and 1 patient with pulmonary hemorrhage. There were 7 deaths （17.5%） in the delayed recovery group and 2 deaths （2.7%） in the normal group， and the in-hospital mortality of the delayed recovery group was significantly higher than that of the normal group （P=0.016）. A total of 94 patients （including 65 patients in the normal group and 29 patients in the delayed recovery group） were followed up for 4-95 months. Eight patients （including 5 patients in the normal group and 3 patients in the delayed recovery group） died during follow-up， including 2 patients with stroke， 3 patients with heart failure， 2 patients with pulmonary hemorrhage and 1 patient with unknown cause. Ten patients were lost during follow-up. Univariate analysis showed that age （P=0.042）， hypertension （P=0.017）， emergency surgery （P=0.001）， cardiopu- lmonary bypass （CPB） time （P=0.007）， aortic cross-clamp time （P=0.021）， and blood transfusion（P=0.012）were risk factors of delayed recovery of consciousness after aortic arch surgery. Multivariate logistic regression showed that emergency surgery （P=0.005） and CPB time＞240 minutes （P=0.000） were independent risk factors of delayed recovery of consciousness after aortic arch surgery. Conclusion Delayed recovery of consciousness after aortic arch surgery is attributed to a combination of many risk factors. Correct patient diagnosis， lesion site and involved scope should be made clear preoperatively in order to choose appropriate surgical strategies. During the surgery， strengthened brain protection， shortened operation time， improved surgical techniques， and perioperative stable circulation maintenance are all important measures to prevent delayed recovery of consciousness after aortic arch surgery.
ObjectiveTo investigate the impact of deep hypothermic circulatory arrest (DHCA) with antegrade cerebral perfusion (ACP) on cognitive function of patients undergoing surgical therapy for acute Stanford type A aortic dissection (AD). MethodsBetween January 2009 and March 2012, 48 patients with acute Stanford type A AD underwent Sun's procedure (aortic arch replacement combined with stented elephant trunk implantation) under DHCA with ACP in Nanjing Hospital affiliated to Nanjing Medical University. There were 40 males and 8 females with their age of 51.3±13.6 years. Circulatory arrest time and time for postoperative consciousness recovery were recorded. Preoperative and postoperative cognitive functions of each patient were evaluated by mini-mental status examination (MMSE). ResultsMean cardiopulmonary bypass time of the 48 patients was 237.3±58.5 minutes, and mean circulatory arrest time was 37.3 ±6.9 minutes. Four patients died postoperatively with the causes of death including lung infection, multiple organ dysfunction syndrome, myocardial infarction and acute respiratory distress syndrome. Forty-one patients recovered their consciousness within 24 hours postoperatively, and the mean time for postoperative consciousness recovery was 15.3±6.5 hours. Preoperative MMSE score was 28.6±1.1 points, and MMSE score at 1 week postoperatively was 23.6±4.5 points. Thirty-one patients were followed up for 6 months with the follow-up rate of 70.45%. The average MMSE score of the 31 patients at 6 months after surgery was 27.6±2.1 points which was significantly higher than postoperative average MMSE score (P < 0.05), but not statistically different from preoperative average MMSE score (P > 0.05). ConclusionsDHCA with ACP can provide satisfactory cerebral protection for patients undergoing surgical therapy for acute Stanford type A AD, but patients' cognitive function may be adversely affected in the short term. As long as cerebral infarction or hemorrhage is excluded in CT scan of the brain, such adverse impact may generally disappear automatically within 6 months after surgery.
Objective To investigate different gases and hematocrits on cerebral injury during deep hypothermic circulatory arrest (DHCA) in a piglet model including monitoring by near-infrared spectroscopy (NIRS). Methods Twenty-four piglets were assigned to 4 groups with respect to different blood gas and hematocrit during DHCA. Group A: hematocrit was maintained between 0.25 to 0.30, pH-stat strategy during cooling phases and alpha stat strategy in other phases; group B: hematocrit was maintained between 0.25 to 0.30 and alpha stat strategy; group C: hematocrit was maintained between 0.20 to 0.25, pH-stat strategy during cooling phases and alpha stat strategy in other phases; group D: hematocrit was maintained between 0.20 to 0.25 and alpha stat strategy. Cerebral oxygenations of piglets were monitored continuously by NIRS. The brain was fixed in situ at 6 hours after operation and a histological score for neurological injury was assessed. Results Oxygenated hemoglobin (HbO2) and total hemoglobin (HbT) signals detected by NIRS were significantly lower in group D than those in group A and group B during cooling (Plt;0.05). Oxygenated hemoglobin nadir time was significantly shorter in group A(Plt;0.05). All piglets with oxygenated hemoglobin signal nadir time less than 25 minutes were free from histological evidence of brain injury. Conclusion Combination of pH-stat strategy and higher hematocrit reduces neurological injury after DHCA.
Objective To compare the changes between deep hypothermic circulatory arrest (DHCA) with deep hypothermic low flow (DHLF) cardiopulmonary bypass (CPB) on pulmonary surfactant (PS) activity in infants with congenital heart disease. Methods Twenty infants with ventricular septum defect and pulmonary hypertension were assigned to either DHCA group or DHLF group according to the CPB methods respectively. Measurements of saturated phosphatidylcholine /total phospholipids (SatPC /TPL), saturated phosphatidylcholine/ total protein (SatPC/TP) and static pulmonary compliance were performed before institution of CPB, 5 minutes after cessation of CPB and 2 hours. Results The length of ICU stay in DHLA group was significantly longer ( P lt;0 05) than that in DHCA group. SatPC/TPL, SatPC/TP and static pulmonary compliance in DHLF group were significantly lower compared with DHCA group ( P lt;0.01). Conclusion DHLF could lower the PS activity level significantly as compared with DHCA in infants with congenital heart disease.
ObjectiveTo establish a novel animal model of deep hypothermic circulatory arrest (DHCT) in rabbits without thoracotomy, and investigate acute kidney injury (AKI) induced by DHCT and early novel biomarkers of AKI. MethodsForty-two New Zealand big ear rabbits (3.5-4.0 kg, male or female) were randomly divided into 2 groups with 21 rabbits in each group. Cardiopulmonary bypass (CPB) was established via the right carotid artery and jugular vein in both groups. In Group A, CPB continued when the rectal temperature was maintained at 28℃. In group B, DHCT started when the rectal temperature reached 16℃ to 18℃ and lasted for 60 minutes before CPB was resumed and rewarming was started. The rectal temperature was restored to 35℃ within 30 minutes, then CPB was maintained for 30 minutes. CPB time was same in both groups. Preoperatively and 6 hours, 24 hours and 48 hours after the operation, venous blood samples were taken to examine serum creatinine (Cr) and β-trace protein (β-TP), and urine samples were taken to examine neutrophil gelatinase-associated lipocalin (NGAL). Four rabbits were sacrificed at respective above time points to measure renal malondialdehyde (MDA) content. Hematoxylin-Eosin (HE) staining, TUNEL assay and transmission electron microscopy were used to examine morphological changes of renal tubular epithelial cells (TECs). ResultsFour rabbits died in group A and five rabbits died in Group B during the experiment.(1)Blood Cr:There was no statistical difference between different time points in Group A (P > 0.05). In Group B, serum Cr at 24 hours after the operation was significantly higher than other time points, and also significantly higher than that of group A (P < 0.05).(2)Blood β-TP and urinary NGAL:There was no statistical difference between different time points in Group A (P > 0.05). In Group B, blood β-TP and urinary NGAL at the time of 6 hours, 24 hours and 48 hours postoperatively were significantly higher than preoperative levels (P < 0.05). Blood β-TP and urinary NGAL at the time of 24 hours postoperatively were significantly higher than other time points (P < 0.05). Blood β-TP and urinary NGAL at the time of 6 hours, 24 hours and 48 hours postoperatively were significantly higher than those of group A (P < 0.05).(3)Renal MDA content of Group B at the time of 24 hours postoperatively was significantly higher than other time points as well as that of Group A (P < 0.05).(4) HE staining showed serious pathological injuries of renal TECs at the time of 24 hours postoperatively in Group B. There was no significant pathological injury of renal TECs at the time of 24 hours postoperatively in Group A. (5)TUNEL-positive rate of group B at the time of 24 hours postoperatively was significantly higher than other time points as well as that of group A (P < 0.05).(6)Transmission electron microscope showed serious pathological injuries of renal TECs organelles at the time of 24 hours postoperatively in Group B. There was no significant pathological injury of renal TECs organelles in Group A. ConclusionsThis DHCT rabbit model without thoracotomy is a simple, convenient, and economical animal model with long-term animal survival for the study of DHCT-induced organ injury. AKI is most serious at the time of 24 hours after DHCA. Blood β-TP and urinary NGAL can be used as early biomarkers of DHCT-induced AKI.
Objective To observe the influence of edaravone perfusion via the pulmonary artery on postoperative lung tissue and lung function during pulmonary ischemia in deep hypothermic circulatory arrest （DHCA）， and explore its possible mechanism. Methods A total of 24 healthy New Zealand white big-ear rabbits were randomly divided into three groups： （1） control group： DHCA model under cardiopulmonary bypass （CPB） was established； （2）low potassium dextran （LPD）group： LPD solution perfusion via the pulmonary artery after the establishment of DHCA； （3）edaravone group：LPD solution containing edaravone （5 mg/kg） perfusion via the pulmonary artery after the establishment of DHCA. Oxygenation index and lung compliance were observed at the time of baseline condition， recovery of ventilation， 1 hour and 2 hours after recovery of ventilation， and postoperative lung function of the three groups were compared. Malondialdehyde （MDA） and superoxide dismutase （SOD） in pulmonary venous blood were measured. All the rabbits were sacrificed after the operation. HE staining and immunohistochemistry were performed on the lung tissues to investigate lung structure changes and inflammatory reaction. Transmission electron microscopy was used to compare ultrastructural changes of lung.Results There were no statistical difference in oxygenation index， lung compliance， MDA and SOD among the 3 groups under the baseline condition （P＞0.05）. After recovery of ventilation， oxygenation index and lung compliance deteriorated to varying degrees in all 3 groups. Oxygenation index and lung compliance of the control group and LPD group at the time of recovery of ventilation， 1 hour and 2 hours after recovery of ventilation were significantly lower than those of edaravone group （oxygenation index：recovery of ventilation and in control group and edaravone group: 198.25±11.02 mm Hg vs. 244.87±13.05 mm Hg；lung compliance：one hour after recovery ventilation in control group and edaravone group：45.88±1.64 ml/cm H2O vs. 59.75±2.38 ml/cm H2O；P＜0.05）. After CPB removal， MDA levels were increased to varying degrees in all 3 groups. MDA levels of the control group and LPD group at the time of CPB removal， 1 hour and 2 hours after CPB removal were significantly higher than those of edaravone group （P＜0.05）. After CPB removal， SOD levels were decreased to varying degrees in all 3 groups. SOD levels of the control group and LPD group at the time of CPB removal， 1 hour and 2 hours after CPB removal were significantly lower than those of edaravone group （P＜0.05）. HE staining showed clear lung structure， less red blood cell leakage， less inflammatory cell infiltration， and less alveolar fluid accumulation in the edaravone group. Immunohistochemistry showed that integral light density of interleukin 6 （IL-6）in edaravone group was significantly lower than those of the LPD group and control group （14.44±1.75 vs. 20.18±2.22， P＜0.05）. Transmission electron microscopy showed integral basement membrane structure， clear blood gas barrier structure， significantly larger number of type II epithelial cells， abundant but not swollen mitochondria and lamellar bodies in the cytoplasm in the edaravone group， which were destroyed in varying degrees in the LPD group and control group. Conclusion Pulmonary artery perfusion of protective solution in low temperature can significantly reduce lung injury induced by DHCA and CPB. Protective solution containing edaravone in low temperature can better decrease lung injury and protect oxygenation.