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.
To valuate cerebral protection by retrograde cerebral perfusion (RCP) via superior vena cava,the study results for the last ten years have been reviewed.RCP is regarded as an assistant method in deep hypothermic circulatory arrest(DHCA) in that it provides partial brain blood flow,maintains a low brain temperature,optimizes cerebral metabolic function during DHCA by supplying oxygen and some nutrient and removal of catabolic products;it also reduces the incidence of cerebral embolization by flushing out air...
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.
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.
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.
ObjectiveTo investigate the incidence of acute kidney injury (AKI) after deep hypothermic circulatory arrest (DHCA), to explore the risk factors and prognosis of postoperative AKI, and to establish a relatively accurate preoperative risk assessment strategy and prevention measures.MethodsThe clinical data of 252 patients who underwent deep hypothermic circulatory surgery in our hospital from January 2014 to October 2018 were retrospectively analyzed. There were 179 males and 73 females with an average age of 53.6±11.6 years. The patients were divided into an AKI group and a non-AKI group according to the AKI diagnostic criteria developed by kidney disease improving global outcomes (KDIGO). The data of the two groups were compared, and the risk factors related to AKI after DHCA were analyzed by single factor and multivariate logistic regression.ResultsAmong the 252 patients enrolled, the incidence of AKI was 69.0%. The postoperative hospital mortality rate was 7.9% (20/252). The univariate analysis showed that the patient's age and body mass index (BMI)≥28 kg/m2, left ventricular ejection fraction<55%, preoperative serum creatinine (Scr)≥110 μmol/L, preoperative estimated glomerular filtration rate (eGFR), Cleveland score and intraoperative cardiopulmonary bypass time, intraoperative infusion of red blood cells, intraoperative infusion of plasma, postoperative mechanical ventilation time≥40 h and other indicators were significantly different between the two groups (P<0.05); multivariate logistic regression analysis showed that there was significant difference between the two groups in age (OR=1.040, 95% CI 1.017–1.064, P=0.001), BMI≥28 kg/m2 (OR=2.335, 95%CI 1.093–4.990, P=0.029), eGFR<90 mL/(min·1.73 m2) (OR=2.044, 95%CI 1.082–3.863, P=0.028), preoperative Cleveland score (OR=1.300, 95%CI 1.054–1.604, P=0.014) and intraoperative cardiopulmonary bypass time (OR=1.009, 95%CI 1.002–1.017, P=0.014).ConclusionThe incidence of AKI is higher after DHCA. Patients with postoperative AKI have longer hospital stay and higher risk of hospitalization death. The age of patients, BMI≥28 kg/m2, eGFR<90 mL/(min·1.73) m2, Cleveland score, intraoperative extracorporeal circulation time are independent risk factors for AKI after DHCA.
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.
Abstract: Objective To observe the influence of various methods of cerebral protection during deep hypothermic circulatory arrest (DHCA ) on S-100 protein. Methods Eighteen dogs were randomly and equally divided into three groups: the deep hypothermic circulatory arrest (DHCA group ) , the DHCA with retrograde cerebral perfusion (DHCA + RCP group ) , and the DHCA with intermittent antegrade cerebral perfusion (DHCA + IACP group ). Upon interruption of cardiopulmonary bypass (CPB) , the nasopharyngeal temperature was slowly lowered to 18℃, before CPB was discontinued for 90 minutes, after 90 minutes, CPB was re-established and the body temperature was gradually restored to 36℃, then CPB was terminated. Before the circulatory arrest, 45min, 90min after the circulatory arrest and 15min, 30min after re-established of CPB, blood samples were drawn from the jugular veins fo r assay of S-100 protein. Upon completion of surgery, the dogs was sacrificed and the hippocampus was removed from the brain, properly processed for examination by transmission electron microscope for changes in the ultrastructure of the brain and nerve cells. Results There was no significant difference in the content of S-100 protein before circulatory arrest among all three groups (P gt; 0.05). After circulatory arrest, DHCA and DHCA +RCP group showed an significant increase in the content of S-100 protein (P lt; 0.01). There was no significant difference in the content of S-100 protein after circulatory arrest in DHCA + IACP group. Conclusion Cerebral ischemic injuries would occur if the period of DHCA is prolonged. RCP during DHCA would provide protection for the brain to some extent, but it is more likely to cause dropsy in the brain and nerve cells. On the other hand IACP during DHCA appears to provide better brain protection.
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.
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.
