Type A Aortic Dissection Following Heart Transplantation.

Cannulation strategies in aortic arch surgeries are a matter of immense discussion. Majority of time deep hypothermic circulatory arrest (DHCA) is the way out, but it does come with its set of demerits. Here we demonstrate a case with aortic arch dissection dealt with dual cannulation strategy in axillary and femoral artery without need for DHCA and ensuring complete neuroprotection of brain and spinal cord without hinderance of time factor. Inception of new ideas like this may decrease the need for DHCA and hence its drawbacks, thus decreasing the morbidity and mortality associated.

Hypothermia in patients with cardiac arrest prior to ECMO-VA: Insight from the HYPO-ECMO trial.

AIM: Venoarterial extracorporeal membrane oxygenation (VA-ECMO) has become a common intervention for patients with cardiogenic shock (CS), often complicated by cardiac arrest (CA). Moderate hypothermia (MH) has shown promise in mitigating ischemia-reperfusion injury following CA. The HYPO-ECMO trial aimed to compare the effect of MH versus normothermia in refractory CS rescued by VA-ECMO. The primary aim of this non-predefined post hoc study was to assess the treatment effect of MH in the subgroup of patients with cardiac arrest (CA) within the HYPO-ECMO trial. Additionally, we will evaluate the prognostic significance of CA in these patients. METHODS: This post hoc analysis utilized data from the randomized HYPO-ECMO trial conducted across 20 French cardiac shock care centers between October 2016 and July 2019. Participants included intubated patients receiving VA-ECMO for CS for less than 6 h, with 334 patients completing the trial. Patients were randomized to early MH (33-34 °C) or normothermia (36-37 °C) for 24 h. RESULTS: Of the 334 patients, 159 (48%) experienced preceding CA. Mortality in the CA group was 50.9% at 30 days and 59.1% at 180 days, compared to 42.3% and 51.4% in the no-CA group, respectively (adjusted risk difference [RD] at 30 days, 8.1% [-0.8 to 17.1%], p = 0.074 and RD at 180 days 7.0% [-3.0 to 16.9%], p = 0.17). MH was associated with a significant reduction in primary (RD -13.3% [-16.3 to -0.3%], p = 0.031) and secondary outcomes in the CA group only (p < 0.025 for all), with a significant interaction between MH and CA status for 180-day mortality [p = 0.03]. CONCLUSIONS: This post hoc analysis suggests that MH shows potential for reducing mortality and composite endpoints in patients with cardiac arrest and refractory CS treated with VA-ECMO without an increased risk of severe bleeding or infection. Further research is needed to validate these findings and elucidate underlying mechanisms.

Is Deep Hypothermic Cardiac Arrest Mandatory in Aortic Arch Surgeries?

Cannulation strategies in aortic arch surgeries are a matter of immense discussion. Majority of time deep hypothermic circulatory arrest (DHCA) is the way out, but it does come with its set of demerits. Here we demonstrate a case with aortic arch dissection dealt with dual cannulation strategy in axillary and femoral artery without need for DHCA and ensuring complete neuroprotection of brain and spinal cord without hinderance of time factor. Inception of new ideas like this may decrease the need for DHCA and hence its drawbacks, thus decreasing the morbidity and mortality associated.

Cannula Placement for Cerebral Protection Without Circulatory Arrest in Patients Undergoing Hemiarch Aortic Aneurysm Repair.

BACKGROUND: Aortic aneurysms involving the proximal aortic arch, which require hemiarch-type repair, typically require circulatory arrest with antegrade cerebral perfusion. Left carotid antegrade cerebral perfusion (LCP) via distal arch cannulation without circulatory arrest was used in this study's patient population. The goal was to assess the operative efficiency and clinical outcomes of using a distal arch cannulation technique that would not require any hypothermic circulatory arrest (HCA) time compared with more traditional brachiocephalic artery cannulation with right-sided unilateral antegrade cerebral perfusion (RCP) and HCA. METHODS: A single-center retrospective review of patients with replacement of the distal ascending aorta involving the proximal arch was performed. Patients with an intramural hematoma or dissection were excluded. Between January 2015 and December 2019, 68 adult patients had undergone a hemiarch repair because of aneurysmal disease. Analysis of baseline demographics, operative data, and clinical outcomes was performed. RESULTS: Comparing the 68 patients: 21 patients were treated with RCP (via brachiocephalic artery graft with HCA), and 47 patients were treated with LCP (via distal aortic arch cannulation with cross-clamp between the brachiocephalic and left common carotid arteries without HCA). Baseline characteristics and outcomes were evaluated for both groups. The LCP group was younger (LCP median [IQR] age, 60 [53-65] years vs RCP median [IQR] age, 67 [59-71] years]. Sex, race, body mass index, comorbidities, and ejection fraction were similar between the groups. Cardiopulmonary bypass time (LCP, 123 minutes vs RCP, 149 minutes) and unilateral cerebral perfusion time (LCP, 17 minutes vs RCP, 22 minutes) were longer in the RCP group. Bleeding, prolonged ventilatory support, kidney failure, and length of stay were similar. In-hospital mortality was 2% in the LCP group vs 0% in the RCP group. Stroke occurred in 2 patients (4.2%) in the LCP group and in 0% of the RCP group. Mortality at 6 months in the LCP and RCP groups was 3% and 10%, respectively. CONCLUSION: Distal arch cannulation with LCP without HCA is a reasonable and safe alternative strategy for patients requiring hemiarch replacement for aneurysmal disease. This technique may provide additional benefits by avoiding circulatory arrest in these complex cases.

Long-term survival after cardiac arrest in patients undergoing emergent coronary angiography.

AIM: To determine long-term survival of patients after cardiac arrest undergoing emergent coronary angiography and therapeutic hypothermia. METHODS: We analysed data from patients treated within the regional STEMI Network from January 2015 to December 2020. The primary endpoint was all-cause mortality at median follow-up. Secondary endpoints were periprocedural complications (arrhythmias, pulmonary edema, cardiogenic shock, mechanical complication, stent thrombosis, reinfarction, bleeding) and 6-month all-cause death. A landmark analysis was performed, studying two time periods; 0-6 months and beyond 6 months. RESULTS: From a total of 24,125 patients in the regional STEMI network, 494 patients who suffered from cardiac arrest were included and divided into two groups: treated with (n = 119) and without therapeutic hypothermia (n = 375). At median follow-up (16.0 [0.2-33.3] months), there was no difference in the adjusted mortality rate between groups (51.3 % with hypothermia vs 48.0 % without hypothermia; HRadj1.08 95%CI [0.77-1.53]; p = 0.659). There was a higher frequency of bleeding in the hypothermia group (6.7 % vs 1.1 %; ORadj 7.99 95%CI [2.05-31.2]; p = 0.002), without difference for the rest of periprocedural complications. At 6-month follow-up, adjusted all-cause mortality rate was similar between groups (46.2 % with hypothermia vs 44.5 % without hypothermia; HRadj1.02 95%CI [0.71-1.47]; p = 0.900). Also, no differences were observed in the adjusted mortality rate between 6 months and median follow-up (9.4 % with hypothermia vs 6.3 % without hypothermia; HRadj2.02 95%CI [0.69-5.92]; p = 0.200). CONCLUSIONS: In a large cohort of patients with cardiac arrest within a regional STEMI network, those treated with therapeutic hypothermia did not improve long-term survival compared to those without hypothermia.

The Precision Between Transcutaneous Carbon Dioxide Versus PaCO2 in Infants Undergoing Therapeutic Hypothermia.

BACKGROUND: Infants with hypoxic-ischemic encephalopathy are often treated with therapeutic hypothermia and high-frequency ventilation. Fluctuations in PaCO2 during therapeutic hypothermia are associated with poor neurodevelopmental outcomes. Transcutaneous CO2 monitors offer a noninvasive estimate of PaCO2 represented by transcutaneously measured partial pressure of carbon dioxide (PtcCO2 ). We aimed to assess the precision between PtcCO2 and PaCO2 values in neonates undergoing therapeutic hypothermia. METHODS: This was a retrospective chart review of 10 neonates who underwent therapeutic hypothermia requiring respiratory support over 2 y. A range of 2-27 simultaneous PtcCO2 and PaCO2 pairs of measurements per neonate were analyzed via linear mixed models and a Bland-Altman plot for multiple observations per neonate. RESULTS: A linear mixed-effect model demonstrated that PtcCO2 and PaCO2 (controlling for sex) were similar. The 95% CI of the mean difference ranged from -2.3 to 5.7 mm Hg (P = .41). However, precision was poor as the PtcCO2 ranged from > 18 mm Hg to < 13 mm Hg than PaCO2 values for 95% of observations. CONCLUSIONS: The neonates' PtcCO2 was as much as 18 mm Hg higher to 13 mm Hg lower than the PaCO2 95% of the time. Transcutaneous CO2 monitoring may not be a good trending tool, nor is it appropriate for estimating PaCO2 in patients undergoing therapeutic hypothermia.

Long-term mild hypothermia promotes neuroprotection by antagonizing the rebound of intracranial pressure after traumatic brain injury in rats / 天津医药

Objective To explore the optimal duration of long-term mild hypothermia(MHT)for traumatic brain injury(TBI)in rats,and observe its effect on intracranial pressure(ICP)and neurological function.Methods Forty-eight healthy adult male SD rats were divided into the normal temperature treatment(NT)group,the MHT4 h group,the MHT24 h group and the MHT48 h group by random number table method,with twelve rats in each group.The TBI model of rats was prepared by electronic controllable cortical injury device,and ICP monitoring probe was implanted.After modeling,the NT group was treated with normal temperature(37℃),and the other groups were treated with low temperature(33.0±1.0)℃for 4 h,24 h and 48 h,respectively.ICP was monitored and brain water content(BWC)was calculated after MHT treatment in each group.Blood-brain barrier permeability was determined by Evansland(EB)staining.The expression of 5-bromodeoxyuracil nucleoside(BrdU),neuronal nuclear antigen antibody(NeuN)and leukocyte differentiation antigen 86(CD86)positive cells were detected by immunofluorescence staining.The expressions of B-cell lymphoma-2(Bcl-2),Bcl-2 associated X protein(Bax),inducable nitric oxide synthase(iNOS),interleukin(IL)-10 and arginase 1(Arg-1)were detected by Western blot assay.Results Compared with the NT group,levels of BWC,ICP,EB,and CD86 positive cells,Bax and iNOS expression levels were decreased in the MHT4 h group,the MHT24 h group and the MHT48 h group,and the number of BrdU positive cells and BrdU/NeuN double-labeled positive cells were increased in hippocampus.The expression levels of Bcl-2,IL-10 and Arg-1 were increased(P＜0.01).Compared with the MHT24 h group,levels of BWC,ICP and EB,and CD86 positive cells,Bax and iNOS expression were decreased,and the number of BrdU positive cells and BrdU/NeuN double-labeled positive cells were increased in the MHT48 h group,while levels of Bcl-2,IL-10 and Arg-1 expression were increased(P＜0.01).Conclusion Long-term MHT can promote the proliferation and differentiation of neurons,inhibit apoptosis and reduce inflammation by suppressing ICP rebound,further promoting neuroprotection after TBI.

Is Deep Hypothermic Cardiac Arrest Mandatory in Aortic Arch Surgeries?

ABSTRACT Cannulation strategies in aortic arch surgeries are a matter of immense discussion. Majority of time deep hypothermic circulatory arrest (DHCA) is the way out, but it does come with its set of demerits. Here we demonstrate a case with aortic arch dissection dealt with dual cannulation strategy in axillary and femoral artery without need for DHCA and ensuring complete neuroprotection of brain and spinal cord without hinderance of time factor. Inception of new ideas like this may decrease the need for DHCA and hence its drawbacks, thus decreasing the morbidity and mortality associated.

Type A Aortic Dissection Following Heart Transplantation

ABSTRACT Cannulation strategies in aortic arch surgeries are a matter of immense discussion. Majority of time deep hypothermic circulatory arrest (DHCA) is the way out, but it does come with its set of demerits. Here we demonstrate a case with aortic arch dissection dealt with dual cannulation strategy in axillary and femoral artery without need for DHCA and ensuring complete neuroprotection of brain and spinal cord without hinderance of time factor. Inception of new ideas like this may decrease the need for DHCA and hence its drawbacks, thus decreasing the morbidity and mortality associated.

The Learning Curve of Total Arch Replacement via Single Upper Hemisternotomy Approach in Aortic Dissection.

Purpose: Upper hemisternotomy (UHS) has benefits over conventional full sternotomy because it ameliorates trauma during cardiac surgery. Owing to its challenging and technically demanding nature, this incision in acute type A aortic dissection (ATAAD) has rarely been reported. This study aimed to analyze the learning curve of total arch replacement (TAR) with moderate hypothermic circulatory arrest via a single UHS approach, which is necessary to guide the training of surgeons in adopting minimally invasive procedures. Patients and Methods: A total of 202 consecutive patients who were definitively diagnosed with ATAAD between July 2016 and June 2021 were enrolled in this retrospective analysis. Patients were divided into three groups based on cumulative sum plots for circulatory arrest time in chronological order. Perioperative characteristics were compared between the groups. Results: There was significant difference in the circulatory arrest time and cross-clamp time respectively among three groups (39.0 min vs 28.0 min vs 15.0 min, P < 0.001; 104.5 min vs 106.2 min vs 84.1 min, P < 0.001). The ventilation time and first 24-h chest tube drainage were statistically different among groups (35.5 h vs 24.0 h vs 19.0 h, P = 0.031; 220.0 mL vs 192.5 mL vs 125.5 mL, P = 0.043). No other clinical outcome was observed as significant difference. Conclusion: A cardiac surgeon can convert a conventional full sternotomy to a single UHS for TAR after experiencing a learning curve, to ensure patient safety. The mastery of this minimally invasive surgical technique may be beneficial for the prognosis of patients with ATAAD.

[Procedure after successful cardiopulmonary resuscitation-Cooling or no more cooling?] / Vorgehen nach erfolgreicher Reanimation ­ kühlen oder nicht mehr kühlen?

Approximately 84 out of 100,000 inhabitants in Europe suffer from an out of hospital cardiac arrest (OHCA) each year. The mortality after cardiac arrest (CA) is high and is particularly determined by the predominant cardiogenic shock condition and hypoxic ischemic encephalopathy. For almost two decades hypothermic temperature control was the only neuroprotective intervention recommended in guidelines for postresuscitation care; however, recently published studies failed to demonstrate any improvement in the neurological outcome with hypothermia in comparison to strict normothermia in postresuscitation treatment. According to the European Resuscitation Council (ERC) and European Society of Intensive Care Medicine (ESICM) guidelines published in 2022, unconscious adults after CA should be treated with temperature management and avoidance of fever; however, many questions remain open regarding the optimal target temperature, the cooling methods and the optimal duration. Despite these currently unanswered questions, a structured and high-quality postresuscitation care that includes a targeted temperature management should continue to be provided for all patients in the postresuscitation phase, independent of the selected target temperature. Furthermore, fever avoidance remains an important component of postresuscitation care.

Comparison between selective head cooling and whole-body cooling in neonatal therapeutic hypothermia / Comparação entre resfriamento seletivo da cabeça e resfriamento de corpo inteiro na hipotermia terapêutica neonatal

INTRODUCTION: Experimental evidence, as well as improved clinical studies of the reduction of brain injury and, improves the neurological outcome, in newborns with hypoxic-ischemic encephalopathy (HIE) occurring in therapeutic hypothermia (TH). OBJECTIVE: To verify the potential of hypothermic hypoxic-ischemic encephalopathy (HIE) therapy in neonatal asphyxia, based on literature data, comparing the benefits between selective head cooling (SHC) and whole-body cooling (WBC), see that the use of TH as a standard treatment in newborns with moderate or severe HIE has been adopted. METHODS: A search was performed in the PubMed and SciELO databases of human studies, using the keywords "Therapeutic Hypothermia", "Induced Hypothermia", and "Hypoxic-Ischemic Encephalopathy", "Selective cooling of the head", "Total body cooling" and its variables. RESULTS: Eleven articles were selected to compose the review, after detailed reading. There is a consensus, that the reduction of the risk of death or disability at 18 months of life in neonates with moderate to severe HIE, occurs to TH through the techniques of WBC or SHC. It was found in the studies that there is no difference in terms of adverse effects between the two methods. As for radiological changes, such as hypoxic-ischemic injuries and the incidence of seizures after cooling, they are more frequent with SHC. CONCLUSION: Both WBC and SHC demonstrated neuroprotective properties, although WBC provides a broader area of brain protection. However, no significant differences were found between the methods in terms of adverse effects and beneficial short or long-term results.

INTRODUÇÃO: Evidências experimentais, assim como estudos clínicos, sugerem a redução da lesão cerebral e melhora do desfecho neurológico, em recém-nascidos com encefalopatia isquêmica hipóxica (EHI) submetidos à hipotermia terapêutica (HT). OBJETIVO: Verificar a potencialidade da terapia hipotérmica de encefalopatia hipóxico-isquêmica (EHI) na asfixia neonatal, com base em dados da literatura, comparando os benefícios entre o resfriamento seletivo da cabeça (RSC) e o resfriamento de corpo inteiro (RCI), visto que o uso de hipotermia terapêutica (HT) como tratamento padrão em recém-nascidos com EHI moderada ou grave tem sido amplamente adotada. MÉTODOS: Foi realizada uma busca nas bases de dados PubMed e SciELO de estudos em humanos, utilizando-se as palavras-chave "Therapeutic Hypothermia", "Induced Hypothermia", "Hypoxic-Ischemic Encephalopathy", "selective head cooling", "whole body cooling" e suas respectivas variáveis. RESULTADOS: Foram selecionados 11 artigos para compor a revisão, após leitura detalhada. É consenso, a redução do risco de morte ou incapacidade aos 18 meses de vida nos neonatos com EHI moderado a grave, submetidos à HT através das técnicas de RCI ou RSC. Constatou-se diante dos estudos que não há diferença em termos de efeitos adversos entre os dois métodos. Quanto às alterações radiológicas, as lesões hipóxico-isquêmicas e incidência de convulsões após o resfriamento são mais frequentes com o RSC. CONCLUSÃO: Tanto RCI quanto o RSC demonstraram propriedades neuroprotetoras, embora o RCI proporcione uma área de proteção cerebral mais ampla. No entanto, não foram constatadas diferenças significativas entre os métodos quanto a efeitos adversos e a resultados benéficos em curto e longo prazo.

Protective effect of mild hypothermic antegrade machine perfusion on ischemic brain injury in dogs / 中华创伤杂志

Objective:To investigate the protective effect of hypothermic antegrade machine perfusion against canine ischemic brain injury.Methods:Thirteen beagle dogs were divided into the mild hypothermia with perfusion group ( n=6) and normothermia with perfusion group ( n=7) according to the random number table. The model of ischemic brain injury was established by neck transection. After 1 hour of ischemic circulatory arrest, the perfusion fluid based on autologous blood was continuously perfused through bilateral common carotid artery for 6 hours. The temperature of the perfusion fluid was set at 33 ℃ in the mild hypothermia with perfusion group and 37℃ in the normothermia with perfusion group, respectively. Blood oxygen saturation was recorded at 0, 1, 2, 3, 4, 5 and 6 hours after the beginning of perfusion to evaluate the perfusate oxygen level. The perfusate was collected, and the levels of Na +, K +, Ca 2+ and glucose as well as the pH value of the perfusate were detected in the two groups. At the end of perfusion, the parietal brain tissues of 1 dog from each group were collected to evaluate the water contents of brain tissues. Nissl staining was used to evaluate the morphological integrity of the pyramidal neurons in the frontal cortex and hippocampus. Neuronal nuclei antigen (NeuN) was used to evaluate the structural and morphological integrity of pyramidal neurons. Immunofluorescence glial fibrillary acidic protein (GFAP) and ionic calcium binding adaptor molecule 1 (Iba1) were used to evaluate the integrity and activity of astrocytes and microglia fragments. Results:At 0, 1, 2, 3, 4, 5 and 6 hours of perfusion, there was no significant difference in the blood oxygen saturation or Na + concentrations between the two groups (all P>0.05); the K + concentrations in the mild hypothermia with perfusion group were (4.57±0.12)mmol/L, (4.67±0.14)mmol/L, (4.27±0.12)mmol/L, (4.45±0.10)mmol/L, (6.60±0.15)mmol/L, (7.37±0.18)mmol/L and (9.03±0.16)mmol/L, respectively, which were significantly lower than those in the normothermia with perfusion group [(4.84±0.10)mmol/L, (5.31±0.13)mmol/L, (5.44±0.24)mmol/L, (5.70±0.18)mmol/L, (7.79±0.18)mmol/L, (10.44±0.40)mmol/L, (10.40±0.41)mmol/L] (all P<0.01). At 0, 1, 2 and 3 hours of perfusion, the Ca 2+ concentrations in the mild hypothermia with perfusion group were (0.72±0.15)mmol/L, (1.55±0.16)mmol/L, (1.62±0.15)mmol/L and (1.88±0.15)mmol/L, respectively, being significantly higher than those in the normothermia with perfusion group [(0.41±0.13)mmol/L, (0.99±0.12)mmol/L, (1.29±0.13)mmol/L, (1.57±0.11)mmol/L] (all P<0.01), and no significant differences were found at other time points (all P>0.05). At 0, 1 and 2 hours of perfusion, the glucose concentrations in the mild hypothermia with perfusion group were (5.75±0.19)mmol/L, (5.17±0.15)mmol/L and (4.72±0.15)mmol/L, respectively, being significantly higher than those in the normothermia with perfusion group [(5.30±0.22)mmol/L, (4.89±0.20)mmol/L, (4.30±0.17)mmol/L] (all P<0.01), with no significant differences found at other time points (all P>0.05). At 2, 3, 4, 5 and 6 hours of perfusion, the pH values of the mild hypothermia with perfusion group were 7.32±0.06, 7.25±0.02, 7.23±0.02, 7.24±0.02 and 7.24±0.02, respectively, being significantly higher than those in the normothermia with perfusion group (7.26±0.01, 7.21±0.01, 7.17±0.02, 7.15±0.02, 7.08±0.02) ( P<0.05 or 0.01), with no significant differences at other time points (all P>0.05). The water content of brain tissues in the mild hypothermia with perfusion group was (74.9±0.4)%, which was significantly lower than (79.9±0.9)% in the normothermia with perfusion group ( P<0.01). Nissl staining showed that the pyramidal neurons in prefrontal cortex and dentate gyrus had good integrity in the mild hypothermia with perfusion group. NeuN immunofluorescence staining showed that the morphology and structure of pyramidal neuron cells in the mild hypothermia with perfusion group were better with clearly visible axons than those in the normothermia with perfusion group, whereas the cytosol was full and swollen with scarce axons in the normothermia with perfusion group. GFAP and Iba1 immunofluorescence staining showed that more structurally intact glial cells, more abnormally active cells, thickener axons and better axon integrity in all directions were found in the mild hypothermia with perfusion group than those in the normothermia with perfusion group. Conclusion:Compared with normal temperature antegrade mechanical perfusion, the mild hypothermia antegrade mechanical perfusion can protect canine brain tissue and alleviate ischemic brain injury by maintaining stable energy and oxygen supply, balancing ion homeostasis and perfusion fluid pH value, reducing tissue edema, and maintaining low metabolism of pyramidal neurons, astrocytes and microglia.

Effects of exosomes derived from cardiac fibroblasts treated with hypothermic hypoxia-reoxygenation on ventricular electrical conduction during hypothermic cardiac ischemia-reperfusion in rats / 中华麻醉学杂志

Objective:To evaluate the effects of exosomes derived from cardiac fibroblasts treated with hypothermic hypoxia-reoxygenation on ventricular electrical conduction during hypothermic cardiac ischemia-reperfusion (I/R) in rats.Methods:SPF neonatal Sprague-Dawley rats of either sex, aged 1-2 days, were used, and primary cardiac fibroblasts were extracted by differential adhesion method. The cells were passaged for 2-4 generations. When the cell density reached 60%-70%, the cells were transferred and exposed to 95% N 2 + 5% CO 2 for 1 h at 4 ℃, and then exposed to 95% air + 5% CO 2 for 24-48 h at 37 ℃, and then exosomes were extracted. Twenty-four SPF healthy adult male Sprague-Dawley rats, aged 2-3 months, weighing 280-360 g, were divided into 3 groups ( n=8 each) according to the random number table method: control group (group C), hypothermic cardiac IR group (I/R group) and exosome + hypothermic cardiac IR group (Exo-IR group). At 48 h before equilibrium perfusion, 1.5 ml (200 μg) of exosomes secreted by cardiac fibroblasts treated with hypothermic hypoxia-reoxygenation was injected into the tail vein in Exo-IR group, and PBS 1.5 ml was injected into the tail vein in C group and IR group each. Group C received 110 min equilibration perfusion. After 20 min of equilibration, the perfusion was suspended for 60 min (global ischemia) followed by 30 min of reperfusion in IR and Exo-IR groups. Microelectrode arrays were applied at 20 min of equilibrium perfusion and 15 and 30 min of reperfusion to obtain myocardial conduction velocity (CV), absolute conduction inhomogeneity (P 5-95) and inhomogeneity index (P 5-95/P 50) on the left ventricular surface of isolated rat hearts. Results:Compared with group C, the CV was significantly decreased at 15 and 30 min of reperfusion, and P 5-95 and P 5-95/P 50 were increased in IR and Exo-IR groups ( P<0.05). Compared with IR group, CV was significantly increased at 15 and 30 min of reperfusion, and P 5-95 and P 5-95/P 50 were decreased in Exo-IR group ( P<0.05). Conclusions:Exosomes derived from cardiac fibroblasts treated with hypothermic hypoxia-reoxygenation can improve ventricular electrical conduction during hypothermic cardiac I/R in rats.

Role of GSTM1 expression in mild hypothermia-induced mitigation of cerebral ischemia-reperfusion injury: relationship with microglial polarization / 中华麻醉学杂志

Objective:To evaluate the role of glutathione S-transferase μ1 (GSTM1) expression in mild hypothermia-induced mitigation of cerebral ischemia-reperfusion (I/R) injury and the relationship with microglial polarization.Methods:Eighty clean-grade healthy male Sprague-Dawley rats, aged 8 weeks, weighing 260-280 g, were divided into 4 groups ( n=20 each) using a random number table method: sham operation group (S group), cerebral I/R group (I/R group), mild hypothermia group (H group), and GSTM1 inhibitor + mild hypothermia group (IH group). The rat model of cerebral I/R injury was prepared using the filament occlusion method. The filament was removed to restore blood flow after the left middle cerebral artery was blocked for 2 h, and the rats′ brain and rectal temperature were maintained at 36-37 ℃ during the period. The vessels were only isolated and ligated without occlusion in S group. In H group, the entire body was wiped with 75% ethanol immediately after removing the filament, and the brain and rectal temperatures were maintained at 32-33 ℃ for 3 h, and the other procedures were the same as those previously described in I/R group. In IH group, GSTM1 inhibitor itaconic acid 8.6 mg/kg was intraperitoneally injected at 24 and 1 h before developing the model, and the other procedures were the same as those previously described in H group. Neurological deficits were evaluated using a modified neurological severity score (mNSS) at 24 h of reperfusion, and then the animals were sacrificed and the brains were removed for observation of cerebral infarction (by TTC staining) and for determination of the expression of GSTM1, M1-type microglial marker inducible nitric oxide synthase (iNOS), and M2-type microglial marker arginase-1 (Arg-1) (by Western blot), expression of GSTM1, iNOS and Arg-1 mRNA (quantitative real-time polymerase chain reaction) and contents of interleukin-6 (IL-6), IL-10, tumor necrosis factor-alpha (TNF-α) and transforming growth factor-beta (TGF-β) (by enzyme-linked immunosorbent assay). Results:Compared with S group, the mNSS and percentage of cerebral infarct size were significantly increased, and the expression of iNOS and Arg-1 protein and mRNA was up-regulated, the expression of GSTM1 and mRNA was down-regulated, and the contents of IL-6, TNF-α, IL-10 and TGF-β were increased in the other three groups ( P<0.05). Compared with I/R group and IH group, the mNSS and percentage of cerebral infarct size were significantly decreased, and the expression of iNOS protein and mRNA was down-regulated, the expression of Arg-1 protein and mRNA and GSTM1 was up-regulated, the contents of TNF-α and IL-6 were decreased, and the contents of TGF-β and IL-10 were increased in H group ( P<0.05). Conclusions:Up-regulated expression of GSTM1 is involved in mild hypothermia-induced mitigation of cerebral I/R injury, which is associated with inhibition of microglial polarization toward the M1 phenotype and promotion of polarization toward the M2 phenotype.

Robotic Level IV Inferior Vena Cava Thrombectomy Using an Intrapericardial Control Technique: Is It Safe Without Cardiopulmonary Bypass?

PURPOSE: We introduce an intrapericardial control technique using a robotic approach in the surgical treatment of renal tumor with level IV inferior vena cava thrombus to decrease the severe complications associated with cardiopulmonary bypass and deep hypothermic circulatory arrest. MATERIALS AND METHODS: Eight patients with level IV inferior vena cava thrombi not extending into the atrium underwent transabdominal-transdiaphragmatic robot-assisted inferior vena cava thrombectomy obviating cardiopulmonary bypass/deep hypothermic circulatory arrest (cardiopulmonary bypass-free group) by an expert team comprising urological, hepatobiliary, and cardiovascular surgeons. The central diaphragm tendon and pericardium were transabdominally dissected until the intrapericardial inferior vena cava were exposed and looped proximal to the cranial end of the thrombi under intraoperative ultrasound guidance. As controls, 14 patients who underwent robot-assisted inferior vena cava thrombectomy with cardiopulmonary bypass (cardiopulmonary bypass group) and 25 patients who underwent open thrombectomy with cardiopulmonary bypass/deep hypothermic circulatory arrest (cardiopulmonary bypass/deep hypothermic circulatory arrest group) were included. Clinicopathological, operative, and survival outcomes were retrospectively analyzed. RESULTS: Eight robot-assisted inferior vena cava thrombectomies were successfully performed without cardiopulmonary bypass, with 1 open conversion. The median operation time and first porta hepatis occlusion time were shorter, and estimated blood loss was lower in the cardiopulmonary bypass-free group as compared to the cardiopulmonary bypass group (540 vs 586.5 minutes, 16.5 vs 38.5. minutes, and 2,050 vs 3,500 mL, respectively). Severe complications (level IV-V) were also lower in the cardiopulmonary bypass-free group than in cardiopulmonary bypass and cardiopulmonary bypass/deep hypothermic circulatory arrest groups (25% vs 50% vs 40%). Oncologic outcomes were comparable among the 3 groups in short-term follow-up. CONCLUSIONS: Pure transabdominal-transdiaphragmatic robot-assisted inferior vena cava thrombectomy without cardiopulmonary bypass/deep hypothermic circulatory arrest represents as an alternative minimally invasive approach for selected level IV inferior vena cava thrombi.

Role of SIRT1/NF-κB signaling pathway in mild hypothermia-induced promotion of microglial polarization during oxygen-glucose deprivation and restoration / 中华麻醉学杂志

Objective:To evaluate the role of Sirtuin 1/nuclear factor κB (SIRT1/NF-κB) signaling pathway in mild hypothermia-induced promotion of microglial polarization during oxygen-glucose deprivation and restoration (OGD/R).Methods:The well-grown BV2 microglia were divided into 4 groups ( n=36 each) using the random number table method: control group (group C), OGD/R group (group O), mild hypothermia group (group M), and mild hypothermia+ SIRT1 specific inhibitor EX527 group (group ME). Cells in group C were commonly cultured without any treatment. Cells in group O were subjected to 3 h of OGD followed by 21 h of restoration of O 2-glucose supply at 37 ℃. Cells in group M were subjected to 3 h of OGD followed by 21 h of restoration of O 2-glucose supply at 33 ℃. Cells in group ME were co-cultured with inhibitor EX527 (final concentration 5 nmol/L) for 12 h in the medium before OGD/R, and the other procedures were conducted as previously described in group M. The cell survival rate was detected by CCK-8 assay. The levels of tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β) and interleukin-10 (IL-10) in supernatant were detected by enzyme-linked immunosorbent assay. The expression of CD206, CD32, inducible nitric oxide synthase (iNOS) and arginine synthase 1 (Arg-1) mRNA was detected by quantitative real-time polymerase chain reaction. The expression of CD206 and CD32 was detected by immunofluorescent staining. The expression of iNOS, Arg-1, SIRT1, NF-κB p65 (p65) and acetylated NF-κB (Ac-p65) was detected by Western blot. Results:Compared with group C, the cell survival rate was significantly decreased, the concentrations of TNF-α, IL-6 and IL-10 in the supernatant were increased, the expression of CD206, Arg-1, CD32 and iNOS was up-regulated, the expression of SIRT1 was down-regulated, and the Ac-p65/p65 ratio was increased in group O ( P<0.05). Compared with group O, the cell survival rate was significantly increased, the concentrations of TNF-α and IL-6 in the supernatant were decreased, the concentration of IL-10 was increased, the expression of CD206, Arg-1 and SIRT1 was up-regulated, the expression of CD32 and iNOS was down-regulated, and the Ac-p65/p65 ratio was decreased in group M ( P<0.05). Compared with group M, the cell survival rate was significantly decreased, the concentrations of TNF-α and IL-6 in the supernatant were increased, the concentration of IL-10 was decreased, the expression of CD206, Arg-1 and SIRT1 was down-regulated, the expression of CD32 and iNOS was up-regulated, and the Ac-p65/p65 ratio was increased in group ME ( P<0.05). Conclusions:SIRT1/NF-κB signaling pathway is involved in mild hypothermia-induced promotion of microglial polarization during OGD/R.

Effects of mild hypothermia on microglia polarization and JAK2/STAT3 signaling pathway during cerebral ischemia-reperfusion in rats / 中华麻醉学杂志

Objective:To investigate the effects of mild hypothermia on microglia polarization and janus kinase 2/signal transduction and transcriptional activation factor 3 (JAK2/STAT3) signaling pathway during cerebral ischemia-reperfusion (I/R) in rats.Methods:Forty-five clean-grade healthy male Sprague-Dawley rats, aged 8 weeks, weighing 260-280 g, were divided into 3 groups ( n=15 each) by the random number table method: sham operation group (S group), cerebral I/R group (I/R) and mild hypothermia group (H group). In I/R group and H group, cerebral I/R was induced by middle cerebral artery occlusion using a nylon thread in anesthetized animals, the nylon thread was removed to restore the perfusion after 2 h of occlusion, and the rectal temperature was maintained at 36-37 ℃ during the period. Group H was wiped with 75% alcohol for 3 h starting from the time point immediately after reperfusion, and the rectal temperature was maintained at 32-33℃. Modified neurological severity score (mNSS) was evaluated at 24 h of reperfusion. Animals were then sacrificed for determination of the cerebral infarct size (using TTC staining), expression of M1 marker inducible nitric oxide synthase (iNOS), M2 marker arginase 1(Arg-1), phosphorylated JAK2(p-JAK2)and phosphorylated STAT3(p-STAT3)(by Western blot), expression of iNOS mRNA and Arg-1 mRNA (by quantitative polymerase chain reaction), and contents of interleukin-6 (IL-6) and IL-10 (by enzyme-linked immunosorbent assay). Results:Compared with group S, mNSS and cerebral infarct size were significantly increased, the expression of iNOS, Arg-1 protein and mRNA in cerebral ischemic penumbral zone was up-regulated, and the p-JAK2/JAK2 ratio, p-STAT3/STAT3 ratio, and contents of IL-6 and IL-10 were increased in the other two groups ( P<0.05). Compared with I/R group, mNSS and cerebral infarct size were significantly decreased, the expression of iNOS protein and mRNA in cerebral ischemic penumbral zone was down-regulated, the expression of Arg-1 and mRNA was up-regulated, and the p-JAK2/JAK2 ratio, p-STAT3/STAT3 ratio and IL-6 content were decreased, and the IL-10 content was increased in group H ( P<0.05). Conclusions:Mild hypothermia can promote the polarization shift of microglia from M1 to M2 phenotype during cerebral I/R and inhibit the central inflammatory responses, and the mechanism may be related to inhibition of JAK2/STAT3 signaling pathway in rats.

Effect of selective cerebral mild hypothermia on SUMO2/3 modification of Drp1 in a rat model of cerebral ischemia-reperfusion / 中华麻醉学杂志

Objective:To evaluate the effect of selective cerebral mild hypothermia on small ubiquitin-like modifier 2/3 (SUMO2/3) modification of dynamin-related protein 1 (Drp1) in a rat model of cerebral ischemia-reperfusion (I/R).Methods:Sixty clean-grade healthy male Sprague-Dawley rats, aged 6-8 weeks, weighing 240-260 g, were divided into 4 groups ( n=15 each) using a random number table method: sham operation group (S group), cerebral I/R group (I/R group), selective cerebral mild hypothermia group (HT group) and normal temperature group (NT group). The operation was performed under the monitoring of cerebral temperature and rectal temperature.Only the cervical blood vessels were exposed in S group, while focal cerebral I/R was induced by 2 h middle cerebral artery occlusion (MCAO) followed by 24 h reperfusion in anesthetized animals in the other three groups.In HT group and NT group, 4 and 37 ℃ normal saline was perfused through the left internal carotid artery at a rate of 80 ml·kg -1·h -1 for 15 min, respectively. Modified neurological severity score (mNSS) was assessed at 24 h of reperfusion. Then the rats were sacrificed under deep anesthesia, brains were removed, brain tissues were obtained for determination of the percentage of cerebral infarct size (by TTC staining), and the ischemic penumbra tissues in the cerebral cortex were removed for examination of the ultra-structural changes of mitochondria (with a transmission electron microscope) and for determination of the SUMO2/3 modification of Drp1 (by CO-IP), expression of total Drp1 (T-Drp1) and total cytochrome c (T-Cytc) (by Western blot), and expression of mitochondrial outer membrane Drp1 (M-Drp1) and cytoplasmic Cytc (C-Cytc) (by Western blot) after isolation of mitochondria and cytoplasm. Results:Compared with S group, the mNSS and percentage of cerebral infarct size were significantly increased, the expression of M-Drp1, T-Drp1, C-Cytc and T-Cytc was up-regulated, and SUMO2/3 modification of Drp1 in ischemic penumbra area was increased ( P<0.05), the fragmentation of mitochondria was aggravated, and cristae rupture and vacuolation were obvious in the other three groups. Compared with I/R group, the mNSS and percentage of cerebral infarct size were significantly decreased, the expression of M-Drp1, T-Drp1, C-Cytc and T-Cytc was down-regulated, SUMO2/3 modification of Drp1 was increased ( P<0.05), the fragmentation of mitochondria was significantly attenuated, and cristae rupture and vacuolation were weakened in HT group. There were no significant differences in these detection parameters between NT group and I/R group ( P>0.05). Conclusions:The mechanism by which selective cerebral mild hypothermia alleviates the cerebral I/R injury is related to increased SUMO2/3 modification of Drp1, decreased binding of Drp1 to mitochondrial outer membrane, and reduced mitochondrial excessive fission in rats.

Temperature Control After In-Hospital Cardiac Arrest: A Randomized Clinical Trial.

BACKGROUND: This study was conducted to determine the effect of hypothermic temperature control after in-hospital cardiac arrest (IHCA) on mortality and functional outcome as compared with normothermia. METHODS: An investigator initiated, open-label, blinded-outcome-assessor, multicenter, randomized controlled trial comparing hypothermic temperature control (32-34°C) for 24 h with normothermia after IHCA in 11 hospitals in Germany. The primary endpoint was all-cause mortality after 180 days. Secondary end points included in-hospital mortality and favorable functional outcome using the Cerebral Performance Category scale after 180 days. A Cerebral Performance Category score of 1 or 2 was defined as a favorable functional outcome. RESULTS: A total of 1055 patients were screened for eligibility and 249 patients were randomized: 126 were assigned to hypothermic temperature control and 123 to normothermia. The mean age of the cohort was 72.6±10.4 years, 64% (152 of 236) were male, 73% (166 of 227) of cardiac arrests were witnessed, 25% (57 of 231) had an initial shockable rhythm, and time to return of spontaneous circulation was 16.4±10.5 minutes. Target temperature was reached within 4.2±2.8 hours after randomization in the hypothermic group and temperature was controlled for 48 hours at 37.0°±0.9°C in the normothermia group. Mortality by day 180 was 72.5% (87 of 120) in hypothermic temperature control arm, compared with 71.2% (84 of 118) in the normothermia group (relative risk, 1.03 [95% CI, 0.79-1.40]; P=0.822). In-hospital mortality was 62.5% (75 of 120) in the hypothermic temperature control as compared with 57.6% (68 of 118) in the normothermia group (relative risk, 1.11 [95% CI, 0.86-1.46, P=0.443). Favorable functional outcome (Cerebral Performance Category 1 or 2) by day 180 was 22.5% (27 of 120) in the hypothermic temperature control, compared with 23.7% (28 of 118) in the normothermia group (relative risk, 1.04 [95% CI, 0.78-1.44]; P=0.822). The study was prematurely terminated because of futility. CONCLUSIONS: Hypothermic temperature control as compared with normothermia did not improve survival nor functional outcome at day 180 in patients presenting with coma after IHCA. The HACA in-hospital trial (Hypothermia After Cardiac Arrest in-hospital) was underpowered and may have failed to detect clinically important differences between hypothermic temperature control and normothermia. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique Identifier: NCT00457431.