The neurologic protection of unilateral versus bilateral antegrade cerebral perfusion in aortic arch surgery with deep hypothermic circulatory arrest: A study of 77 cases

Deep Hypothermic Low Flow Results in Multiple Aspects of Neurological Deficits in Mice by eEF2 Hyperphosphorylation

Postoperative neurological dysfunction is a common complication caused by deep hypothermia with cerebral hypoperfusion during aortic arch surgery, but the exact pathological changes and molecular mechanisms are not yet clear. In this study, we established an adult mouse model of deep hypothermic low flow (DHLF) to simulate the ischemic-reperfusion brain injury during aortic arch surgery. The DHLF-modeled mice showed significant neurological and cognitive dysfunction, accompanied by reduced dendritic spine density and increased glial cell activation in the hippocampus and cortex. DHLF induced proteomic changes primarily involved in synaptic organization in the hippocampus and cortex, with AMPA and NMDA receptor subunits and synaptic activity-dependent proteins markedly downregulated in the hippocampus and/or cortex. Moreover, DHLF also resulted in altered proteome in mRNA translation and inhibition of eukaryotic elongation factor 2 (eEF2), a crucial regulator of translational elongation whose activity is negatively regulated via phosphorylation by eEF2 kinase (eEF2K). Importantly, the administration of the small-molecular eEF2K inhibitor A484954 ameliorated DHLF-induced neurobehavioral dysfunction, dendritic spine reduction, and glial cell activation, suggesting that eEF2K/eEF2 may be a promising therapeutic target in DHLF-induced neurological injury. Our findings revealed new evidence of pathological features, molecular mechanism, and intervention of DHLF-induced cerebral ischemia-reperfusion injury, providing promising insight for developing strategies on reducing postoperative neurological complications after aortic arch surgery.

A comprehensive organ protection strategy in total arch replacement: a propensity-weighted analysis

OBJECTIVES

The goal was to report the outcomes and determine the effectiveness of a comprehensive organ protection strategy in total arch replacement.

METHODS

A total of 350 patients who underwent total arch replacement were enrolled. Fifty-four patients underwent the comprehensive organ protection strategy with bilateral antegrade cerebral perfusion and the aortic balloon occlusion technique (comprehensive strategy group); 296 patients underwent the standard strategy with unilateral antegrade cerebral perfusion (standard strategy group). Inverse probability of treatment weighting was used to balance the baseline characteristics.

RESULTS

After inverse probability of treatment weighting, the comprehensive strategy group had lower incidences of 30-day mortality (0.9% vs 4.9%, P = 0.002), continuous renal replacement therapy (0.6% vs 10.3%, P < 0.001), renal failure (4.6% vs 13.7%, P < 0.001), hepatic dysfunction (11.6% vs 21.1%, P = 0.001) and shorter duration of mechanical ventilation [16 (13, 31) vs 20 (14, 48) h, P = 0.011]. Multivariable logistic analysis showed that the comprehensive strategy was an independent protective factor of 30-day mortality [odds ratio (OR): 0.242, 95% confidence interval (CI): 0.068-0.867, P = 0.029], continuous renal replacement therapy (OR: 0.045, 95% CI: 0.008-0.264, P = 0.001), renal failure (OR: 0.351, 95% CI: 0.156-0.788, P = 0.011) and mechanical ventilation >20 h (OR: 0.531, 95% CI: 0.319-0.883, P = 0.015). Kaplan-Meier analysis showed that mid-term survival was comparable.

CONCLUSIONS

The comprehensive organ protection strategy might improve early survival, reduce the use of continuous renal replacement therapy, have protective effects on the kidney and shorten mechanical ventilation time in total arch replacement. This strategy might be considered a viable alternative in total arch replacement.

Aortic arch replacement in patients with previous repair of acute aortic dissection: a systematic review and meta-analysis

OBJECTIVES

Despite the popularity of the frozen elephant technique procedure in recent years, evidence is scarce regarding its utilization for aortic arch replacement following previous acute aortic dissection repair. In this systematic review and meta-analysis, we aimed to analyse clinical outcomes of aortic arch replacement in patients with previous repair of acute aortic dissection.

METHODS

A systematic literature search on PubMed, MEDLINE via Ovid, Embase, Scopus, and Web of Science until March 2024 was performed for studies on open aortic arch replacement with or without frozen elephant technique procedure in adult patients after previous acute aortic dissection repair. Early and late postoperative mortality were primary, while postoperative complications were secondary outcomes of interest. Additionally, a meta-analysis was performed to pool the early and late postoperative mortality.

RESULTS

A total of 574 studies were identified, of which 9 studies including a total of 677 patients met the eligibility criteria. In-hospital or 30-day postoperative mortality and stroke were 0-17.5% and 0-7.7%, respectively. Duration of follow-up across all studies varied from 1.1 to 5.1 years. All-cause late mortality rate ranges from 5.9% to 30.5%. Aortic reintervention rate was 4.8-38.7%. The pooled early and late mortality rate were 8.7% [95% confidence interval (CI) 5.7-13%; I2 = 52%] and 24.9% (95% CI 19.5-31.1%; I2 = 54%), respectively.

CONCLUSIONS

Current evidence suggest that relatively younger patients with chronic post-dissection aneurysm or residual aortic dissection after acute aortic dissection repair can undergo an aortic arch replacement by a dedicated aortic team with acceptable mortality risk. However, postoperative neurological deficit remains an issue.

Clinical outcome of a branch-first approach with a novel continuous whole-brain perfusion strategy for total arch surgery

BACKGROUND

Cerebral protection strategies have been investigated since the introduction of aortic arch surgery and have been modified over the centuries. However, the cerebral protective effects of unilateral and bilateral antegrade cerebral perfusion are similar, with opportunities for further improvement.

METHODS

A total of 30 patients who underwent total arch surgery were enrolled in this study. Patients were assigned to the novel continuous whole-brain or unilateral antegrade cerebral perfusion group according to the cerebral perfusion technique used. Preoperative clinical data and 1-year postoperative follow-up data were collected and analyzed.

RESULTS

There were no significant differences between the two groups in terms of the incidence of permanent neurological deficit, mortality, or therapeutic efficacy. However, the incidence of temporary neurological dysfunction in the novel whole-brain perfusion group was significantly lower than that in the unilateral antegrade cerebral perfusion group.

CONCLUSIONS

In this study, the branch-first approach with a novel whole-brain perfusion strategy had no obvious disadvantages compared with unilateral antegrade cerebral perfusion in terms of cerebral protection and surgical safety. These findings suggest that this new technique is feasible and has application value for total arch surgery.

Efficacy of pump-controlled selective antegrade cerebral perfusion in total arch replacement: A propensity-matched analysis

Background

Pump-controlled selective antegrade cerebral perfusion (PC-SACP) in total arch replacement (TAR) can regulate cerebral flow accurately, which might be beneficial for cerebral protection. However, the safety of PC-SACP for TAR combined with frozen elephant trunk implantation (FET) in patients with acute Type A dissections (ATAAD) is ambiguous.

Methods

A total of 192 patients with ATAAD underwent TAR at our institution from October 2019 to July 2021. The patients were divided into two groups based on PC-SACP used: PC group (SACP carried out by using a separate pump, n = 35) and Control group (SACP carried out as a traditional method, n = 157). Patients under PC-SACP were propensity-score matched to patients without PC-SACP, resulting in 35 pairs of patients.

Results

Preoperative characteristics, including age, gender, weight, and preoperative creatinine level, were similar between the two groups. Cardiopulmonary bypass time, cross-clamp time, circulatory arrest time, and minimum nasopharyngeal temperature did not differ between the two groups. However, SACP time (54 versus 40, P = 0.001) in the PC group was significantly longer than that in the Control group. The incidence of temporary neurologic dysfunction (5.7% versus 8.6, P = 0.643) showed a no significantly lower trend in the PC group compared with the Control group. Other clinical outcomes showed no significant intergroup differences.

Conclusions

PC-SACP in TAR is safe and feasible and might be beneficial for avoiding brain injury caused by “luxury” perfusion.

Duration of deep hypothermic circulatory arrest for aortic arch surgery: is it a myth, fiction, or scientific leap?

INTRODUCTION

The use of deep hypothermic circulatory arrest (DHCA) to provide aortic surgeons with a bloodless operative field while simultaneously protecting the brain and peripheries from ischemic damage revolutionized cardiac and aortic surgery, and is currently used in specialist centers across the globe. However, it is associated with manifold adverse outcomes, including neurocognitive dysfunction and mortality. This review seeks to analyze the relationship between DHCA duration and clinical outcome, and evaluate the controversies and limitations surrounding its use.

EVIDENCE ACQUISITION

We performed a review of available literature with statistical analysis to evaluate the relationship between DHCA duration (<40 min and >40 min) and key clinical outcomes, including mortality, permanent and temporary neurological deficit, renal damage, admission length, and reintervention rate. The controversies surrounding DHCA use and future directions for care are also explored.

EVIDENCE SYNTHESIS

Statistical analysis revealed no significant association (P>0.05) between DHCA duration and clinical outcomes (early and late mortality rates, neurological deficit, admission length, and reintervention rate), both with and without adjunctive perfusion techniques.

CONCLUSIONS

Available literature suggests that the relationships between DHCA duration (with and without adjunctive perfusion) and clinical outcomes are unclear, and at present not statistically significant. Alternative surgical and endovascular techniques have been identified as promising novel approaches not requiring DHCA, as have the use of biomarkers to enable early diagnosis and intervention for aortic pathologies.

It Is Advisable to Control the Duration of Hypothermia Circulatory Arrest During Aortic Dissection Surgery: Single-Center Experience

Objective: The duration of hypothermic circulatory arrest (HCA) is one of the important factors affecting the prognosis of arch surgery, which is still controversial. The purpose of this study was to investigate the effect of HCA duration on early prognosis in type A aortic dissection (TAAD) patients who underwent arch surgery in our center. Methods: All consecutive patients who underwent surgical treatment for TAAD in Fuwai Hospital from January 2013 to December 2018 were included in this study and divided into four quartile groups based on HCA time. Baseline characteristics, perioperative indicators, and early mortality were statistically analyzed by propensity score matching (PSM) and restricted cubic spline (RCS) method. Perioperative adverse events were confirmed according to the American STS database and Penn classification. Results: About 1,018 consecutive patients (mean age 49.11 ± 1.4 years, male 74.7%) with TAAD treated surgically were eventually included in this study. After PSM, with the prolongation of HCA time, the surgical mortality rates of group [2,15], (15,18], (18,22], and (22,73] were 4.1, 6.6, 7.8, and 10.9% with p = 0.041, respectively. As shown in RCS, the mortality rate increased sharply after the HCA time exceeded 22 min. And from the subgroup analysis, the HCA time of 22 min or less was associated with better clinical outcomes (OR 2.09, 95%CI 1.25-3.45, p = 0.004). Conclusions: The early mortality increases significantly with the duration of HCA time when arch surgery was performed. And multiple systems throughout the body can be adversely affected.

Cannulation strategies in type A aortic dissection: a novel insight narrative review

This review highlights vital details that can be easily overlooked and discuss how to identify and fix failed cannulation from another novel insight. Appropriate arterial cannulation strategy during cardiopulmonary bypass (CPB) in Stanford type A aortic dissection (AAD) is highly necessary to reach satisfactory perfusion effects and appreciable clinical outcomes. Despite several previously published reviews on cannulation strategies in AAD, most focus on the advantages and disadvantages by comparing various cannulation strategies. In fact, most of evidence came from retrospective studies. More importantly, however, some important details and novel approaches maybe overlooked due to variety reasons. These overlooked details also make sense in clinical practice. Papers related to cannulation refer to type AAD were retrieved and analyzed from the PubMed and Medline database. The key words such as “aortic dissection”, “cannula”, “cannulation”, “cannulation strategy”, “cerebral perfusion”, “type I aortic dissection” were conducted and analyzed. In addition, we looked at some new and very significant specific perfusion techniques such as anterograde cerebral perfusion combined with retrograde inferior vena caval perfusion (RIVP) and reperfusion via the right carotid artery before surgery. The arterial cannulation site and strategy should be determined individually. Monitoring measures are very necessary in the whole procedure.

Aortic balloon occlusion technique versus moderate hypothermic circulatory arrest with antegrade cerebral perfusion in total arch replacement and frozen elephant trunk for acute type A aortic dissection

BACKGROUND

Moderate hypothermic circulatory arrest (MHCA) with antegrade cerebral perfusion (ACP) is safe and efficient in total arch replacement (TAR) and frozen elephant trunk (FET) for acute type A aortic dissection (ATAAD). Complications related to hypothermia and ischemia are inevitable, however. The aortic balloon occlusion (ABO) technique is performed to elevate the lowest nasopharyngeal temperature to 28°C and shorten the circulatory arrest time. In this study, we aimed to evaluate the efficacy of this new technique.

METHODS

We reviewed the clinical data of patients with ATAAD who underwent TAR and FET, including 79 who underwent ABO and 109 who underwent MHCA/ACP.

RESULTS

Circulatory arrest time was significantly lower in the ABO group compared with the MHCA/ACP group (mean, 4.8 ± 1.2 minutes vs 18.4 ± 3.1 minutes; P < .001). The composite endpoint was comparable in the 2 groups (11.4% for ABO vs 13.8% for MHCA/ACP; P = .631). Fewer patients in the ABO group developed high-grade acute kidney injury (AKI) according to a modified RIFLE criterion (22.8% vs 36.7%; P = .041), and the rate of hepatic dysfunction was lower in the ABO group (11.4% vs 28.4%; P = .005). Multivariable logistic analysis showed that the ABO technique is protective against duration of ventilation >24 hours (odds ratio [OR], 0.455; 95% confidence interval [CI], 0.234-0.887; P = .021), hepatic dysfunction (OR, 0.218; 95% CI, 0.084-0.561; P = .002), and grade II-III AKI (OR, 0.432; 95% CI, 0.204-0.915; P = .028).

CONCLUSIONS

The ABO technique significantly shortens the circulatory arrest time in TAR and FET. Available clinical data suggest that it has a certain protective effect on the liver and kidney. Future large-sample studies are warranted to thoroughly evaluate this new technique.