Bioinformatic analysis identifies GPR91 as a potential key gene in brain injury after deep hypothermic low flow

Purpose

Explore the transcription change of brain ischemia and reperfusion injury after deep hypothermic low flow.

Method

The data from PRJNA739516 and GSE104036 were obtained for the differentially expressed genes identification, functional enrichment analysis, gene set enrichment analysis, protein-protein interaction construction and hub gene identification. Oxygen and glucose deprivation model was set to validate the hub gene and explore the detailed brain injury mechanism.

Result

Interleukin, immunological response, NF-κB signaling pathway, G protein-coupled receptor signaling pathway and NLRP inflammatory are functional pathway were enriched in differentially expressed genes analysis. Sucnr1, Casr, Cxcr4, C5ar1, Tas2r41, Tas2r60 and Hcar2 were identified and verified in the OGD model. Knocking down GPR91 reduces the inflammatory response after OGD and GPR91 may be involved in the inflammatory pre-reaction through the synergistic activation of NF-κB, NLRP3, and IL-1β respectively.

Conclusion

Our study found that Interleukin, immunological response, NF-κB signaling pathway, G protein-coupled receptor signaling pathway and NLRP inflammatory are all associated with brain ischemia and reperfusion injury after deep hypothermic low flow and GPR91 can activate NF-κB/NLRP3 pathway and trigger the release of IL-1β in this progress.

Cardiopulmonary bypass for total aortic arch replacement surgery: A review of three techniques

One treatment for acute type A aortic dissection is to replace the ascending aorta and aortic arch with a graft during circulatory arrest of the lower body, but this is associated with high mortality and morbidity. Maintaining the balance between oxygen supply and demand during circulatory arrest is the key to reducing morbidity and is the primary challenge during body perfusion. The aim of this review is to summarize current knowledge of body perfusion techniques and to predict future development of this field. We present three perfusion techniques based on deep hypothermic circulatory arrest (DHCA): DHCA alone, DHCA with selective cerebral perfusion, and DHCA with total body perfusion. DHCA was first developed to provide a clear surgical field, but it may contribute to stroke in 4%–15% of patients. Antegrade or retrograde cerebral perfusion can provide blood flow for the brain during circulatory arrest, and it is associated with much lower stroke incidence of 3%–9%. Antegrade cerebral perfusion may be better than retrograde perfusion during longer arrest. In theory, blood flow can be provided to all vital organs through total body perfusion, which can be implemented via either arterial or venous systems, or by combining retrograde inferior vena caval perfusion with antegrade cerebral perfusion. However, whether total body perfusion is better than other techniques require further investigation in large, multicenter studies. Current techniques for perfusion during circulatory arrest remain imperfect, and a technique that effectively perfuses the upper and lower body effectively during circulatory arrest is missing. Total body perfusion should be systematically compared against selective cerebral perfusion for improving outcomes after circulatory arrest.

Aortic Dissection

Acute aortic dissection is a highly morbid condition with high mortality that requires emergent surgical evaluation and repair. The intraoperative management of acute aortic dissection requires the anesthesiologist to do far more than administer anesthesia and begins before the patient arrives at the operative theater. High-fidelity communication with the surgeon, knowledge of the surgical plan, knowledge of the anatomy of the dissection, and a nuanced understanding of aortic dissection pathophysiology are all critical aspects of anesthetic management.

Neuroprotective strategies with circulatory arrest in open aortic surgery - A meta-analysis

Objective

Deep hypothermic circulatory arrest (DHCA) in aortic surgery is associated with morbidity and mortality despite evolving strategies. With the advent of antegrade cerebral perfusion (ACP), moderate hypothermic circulatory arrest (MHCA) was reported to have better outcomes than DHCA. There is no standardised guideline or consensus regarding the hypothermic strategies to be employed in open aortic surgery. Meta-analysis was performed comparing DHCA with MHCA + ACP in patients having aortic surgery.

Methods

A systematic review of the literature was undertaken. Any studies with DHCA versus MHCA + ACP in aortic surgeries were selected according to specific inclusion criteria and analysed to generate summative data. Statistical analysis was performed using STATS Direct. The primary outcomes were hospital mortality and post-operative stroke. Secondary outcomes were cardiopulmonary bypass time (CPB), post-operative blood transfusion, length of ICU stay, respiratory complications, renal failure and length of hospital stay. Subgroup analysis of primary outcomes for Arch surgery alone was also performed.

Results

Fifteen studies were included with a total of 5869 patients. There was significantly reduced mortality (Pooled OR = +0.64, 95% CI = +0.49 to +0.83; p = 0.0006) and stroke rate (Pooled OR = +0.62, 95% CI = +0.49 to +0.79; p < 0.001) in the MHCA group. MHCA was associated significantly with shorter CPB times, shorter duration in ICU, less pulmonary complications, and reduced rates of sepsis. There was no statistical difference between the two groups in terms of circulatory arrest times, X-Clamp times, total operation duration, transfusion requirements, renal failure and post-op hospital stay.

Conclusion

MHCA + ACP are associated with significantly better post-operative outcomes compared with DHCA for both mortality and stroke and majority of the secondary outcomes.

Identifying lncRNA- and Transcription Factor-Associated Regulatory Networks in the Cortex of Rats With Deep Hypothermic Circulatory Arrest

Long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) are involved in the mechanism underlying cerebral dysfunction after deep hypothermic circulatory arrest (DHCA), although the exact details have not been elucidated. To explore the expression profiles of lncRNAs and miRNAs in DHCA cerebral injury, we determined the lncRNA, miRNA and mRNA expression profiles in the cerebral cortex of DHCA and sham rats. First, a rat model of DHCA was established, and high-throughput sequencing was performed to analyze the differentially expressed RNAs (DERNAs). Then, the principal functions of the significantly deregulated genes were identified using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Expression networks (lncRNAs-miRNAs-mRNAs and transcription factors (TFs)-miRNAs-mRNAs) were also established. Finally, the expression of DERNAs was confirmed by quantitative real-time PCR (RT-qPCR). We identified 89 lncRNAs, 45 miRNAs and 59 mRNAs between the DHCA and sham groups and constructed a comprehensive competitive endogenous RNAs (ceRNAs) network. A TF-miRNA-mRNA regulatory network was also established. Finally, we predicted that Lcorl-miR-200a-3p-Ttr, BRD4-Ccl2 and Ep300-miR-200b-3p-Tmem72 may participate in the pathogenesis of DHCA cerebral injury.

Goal-directed cerebral perfusion in aortic arch surgery: scientific leap or hype?

Although significant advancements in cerebral protection strategies in aortic surgery have been achieved in recent years, controversy remains on what constitutes the optimal strategy. Deep hypothermic circulatory arrest alone is a viable approach in many instances, but the need for a prolonged duration of circulatory arrest and increasing case complexity have led to the utilization of adjunctive cerebral perfusion strategies. In this review, we discuss the efficacy of deep hypothermic circulatory arrest and its limitations, the role of retrograde cerebral perfusion and unilateral and bilateral antegrade cerebral perfusion, and the trend towards goal-directed perfusion strategies, all emphasizing the pressing need for randomized clinical trials to better define the optimal strategy.

Evaluation of Acute Aortic Dissection Type a Factors and Comparison the Postoperative Clinical Outcomes between Two Surgical Methods

BACKGROUND

Although aortic dissection is a rare disease, it causes high level of mortality. If ascending aorta gets involved in this disease, it is known as type A. According to small number of studies about this disease in Iran, this study conducted to detect the factors related to acute aortic dissection type A, its surgery consequences and the factors affecting them.

MATERIALS AND METHODS

In this historical cohort study, all patients having acute aortic dissection type A referring to Chamran Hospital from 2006 to 2012 were studied. The impact of two surgical methods including antegrade cerebral perfusion (ACP) and retrograde cerebral one (RCP) on surgical and long-term mortality and recurrence of dissection was determined. The relation of mortality rate and hemodynamic instability before surgery, age more than 70 years old, ejection fraction lower than 50%, prolonged cardiopulmonary bypass pump (CPBP) time and excessive blood transfusion, was assessed.

RESULTS

Surgery and long-term mortality and recurrence of dissection were 35.3%, 30.8% and 30.4%. Surgical and long-term death in the patients being operated by ACP method was lower than those one being operated by RCP (P < 0.001). Excessive blood transfusion and unstable hemodynamic condition had significant effect on surgical mortality (P = 0.014, 0.030, respectively). CPBP time and unstable hemodynamic condition affected long-term mortality significantly (P = 0.002).

CONCLUSION

The result found that ACP is the preferable kind of surgery in comparison with RCP according to the surgical and long-term mortality.

A Clinical Protocol for Goal Directed Cerebral Perfusion during Aortic Arch Surgery

OBJECTIVE

The optimal strategy to deliver antegrade cerebral perfusion for cerebral protection during hypothermic circulatory arrest has not been established. The purpose of this review was to present our current clinical protocol utilizing selective antegrade cerebral perfusion during aortic arch surgery and to compare it to other published experience.

CLINICAL PROTOCOL

Since 2013, our clinical protocol for aortic arch surgery has evolved to using selective antegrade cerebral perfusion via the innominate artery, moderate hypothermia, and ancillary strategies such as goal-directed perfusion (GDP). Other published techniques favored antegrade cerebral perfusion but were limited by smaller cannulae, multiple cannulation sites, and lower cooling temperatures.

CONCLUSION

Our clinical protocol may offer higher flow rates, avoid complications associated with additional cannulae, and provide an easy setup for dual arterial perfusion. Additionally, GDP has enhanced our understanding of metabolic physiology and may facilitate the development of a better cerebral protection strategy.

Thoracic aortic aneurysms in octogenarians: the results of open surgical repair using hypothermic circulatory arrest with antegrade selective cerebral perfusion

OBJECTIVE

Although recent progress has expanded the indications for thoracic aortic surgery to include elderly patients, the procedure remains extremely invasive. We performed a chart review to determine the early and late outcomes of thoracic aortic surgery using hypothermic circulatory arrest (HCA) and antegrade selective cerebral perfusion (ASCP) in octogenarians.

MATERIALS AND METHODS

Of 79 patients who underwent surgery for thoracic aortic aneurysms from April 2007 through December 2012, 8 patients 80 years or older were selected for analysis. Mean age at the time of surgery was 84.3±1.39 years. The diagnoses were aortic dissection in 5 patients and degenerative thoracic aneurysm in 3 patients. All patients underwent surgery with HCA. The lowest body temperature was 25℃ ASCP was used as an additional brain-protection technique. Emergency operations were performed in 5 patients (62.5%).

RESULTS

The mean duration of HCA was 60.4±19.7 minutes, that of aortic cross-clamping time was 143.0±30.4 minutes, and mean pump time was 207.8±44.4 minutes. The hospital mortality rate was 0%. Major postoperative complications occurred in 3 (37.5%) patients: stroke, temporary neurologic dysfunction, and paraparesis in 1 patient each. No patients required temporary dialysis for new-onset renal dysfunction. There were no deaths during the 65-month follow-up period.

CONCLUSION

The early and late outcomes after thoracic aortic surgery at our hospital using HCA with ASCP in octogenarians are acceptable. The operations are performed with an acceptable operative risk, even under emergency situations, including acute aortic dissection.

A meta-analysis of deep hypothermic circulatory arrest versus moderate hypothermic circulatory arrest with selective antegrade cerebral perfusion

INTRODUCTION

A recent concern of deep hypothermic circulatory arrest (DHCA) in aortic arch surgery has been its potential association with increased risk of coagulopathy, elevated inflammatory response and end-organ dysfunction. Recently, moderate hypothermic circulatory arrest (MHCA) with selective antegrade circulatory arrest (SACP) seeks to negate potential hypothermia-related morbidities, while maintaining adequate neuroprotection. The present meta-analysis aims to compare postoperative outcomes in arch surgery using DHCA or MHCA+SACP as neuroprotective strategies.

METHODS

Electronic searches were performed using six databases from their inception to January 2013. Two reviewers independently identified all relevant studies comparing DHCA with MHCA+SACP, as defined by a recent hypothermia temperature consensus. Data were extracted and meta-analyzed according to pre-defined clinical endpoints.

RESULTS

Nine comparative studies were identified for inclusion in the present meta-analysis. Stroke rates were significantly lower in patients undergoing MHCA+SACP (P=0.0007, I(2)=0%), while comparable results were observed with temporary neurological deficit, mortality, renal failure or bleeding. Infrequent and inconsistent reporting of systemic outcomes precluded analysis of other systemic outcomes.

CONCLUSIONS

The present meta-analysis indicated the superiority of MHCA+SACP in terms of stroke risk.

Therapeutic hypothermia: benefits, mechanisms and potential clinical applications in neurological, cardiac and kidney injury

Therapeutic hypothermia involves the controlled reduction of core temperature to attenuate the secondary organ damage which occurs following a primary injury. Clinicians have been increasingly using therapeutic hypothermia to prevent or ameliorate various types of neurological injury and more recently for some forms of cardiac injury. In addition, some recent evidence suggests that therapeutic hypothermia may also provide benefit following acute kidney injury. In this review we will examine the potential mechanisms of action and current clinical evidence surrounding the use of therapeutic hypothermia. We will discuss the ideal methodological attributes of future studies using hypothermia to optimise outcomes following organ injury, in particular neurological injury. We will assess the importance of target hypothermic temperature, time to achieve target temperature, duration of cooling, and re-warming rate on outcomes following neurological injury to gain insights into important factors which may also influence the success of hypothermia in other organ injuries, such as the heart and the kidney. Finally, we will examine the potential of therapeutic hypothermia as a future kidney protective therapy.

Integrated Cerebral Protection Combined Antegrade and Retrograde Cerebral Perfusion during Deep Hypothermic Circulatory Arrest

Objective

Aortic arch surgery requires temporary interruption of cerebral perfusion. Hypothermic circulatory arrest (HCA) is an established method of central nervous system protection for limited periods of absent cerebral blood flow. Adjuncts to increase the safe duration of circulatory arrest include either retrograde cerebral perfusion (RCP) or antegrade cerebral perfusion (ACP), with most complex aortic operations now performed using HCA with ACP. We reasoned that optimal cerebral protection might be achieved with a combination of ACP and RCP (integrated brain protection) and present an early clinical experience that supports this approach.

Methods

The integrated brain protection strategy included sequential overlapping periods of RCP, ACP, and RCP during HCA. Moderate systemic hypothermia (25°C) was used. Patient data were gathered through retrospective chart review.

Results

Between 2008 and 2009, six consecutive patients underwent ascending aortic graft replacement for acute type A dissection using HCA and integrated brain protection. The mean minimum systemic temperature was 22.9 ± 1.8°C, the mean total HCA time was 34 ± 5 minutes, and the mean duration of ACP and RCP was 22 ± 6 and 7 ± 5 minutes, respectively. Patients were awake and followed commands 10.1 ± 3.4 (range, 5–13) hours after operation, and there was no evidence of temporary neurologic dysfunction. There was no operative mortality.

Conclusions

Integrated brain protection using both RCP and ACP during HCA is a promising approach for the safe performance of complex aortic surgery and is worthy of evaluation in larger clinical series.