Original Research: Establishment of an early embolus-related cerebral injury model after cardiopulmonary bypass in miniature pigs

Cardiopulmonary bypass duration is an independent predictor of adverse outcome in surgical repair for acute type A aortic dissection

OBJECTIVE

This study aimed to investigate the relationship between the duration of cardiopulmonary bypass (CPB) and stroke or early death in patients with acute type A aortic dissection (ATAAD) receiving total aortic arch replacement with the frozen elephant trunk procedure (TAR with FET).

METHODS

A retrospective cohort study of 258 consecutive patients was conducted at Beijing Anzhen Hospital from December 2014 to June 2016. Patients who received TAR with FET for ATAAD were included. An adverse outcome (AO) was defined as 30-day mortality or stroke. Additionally, an AO was compared using propensity score matching.

RESULTS

The incidence of AO was 13.6% (n = 35). The 30-day mortality rate was 10.8% and the stroke rate was 9.3%. Patients were aged 47.9 ± 10.6 years old. The duration of CPB was an independent predictor of occurrence of AO after adjusting for confounding factors by multivariable logistic regression analysis (odds ratio 1.101, 95% confidence interval 1.003-1.208). In matched analysis, CPB duration remained a risk factor of AO.

CONCLUSIONS

The duration of CPB is an independent predictor of AO in surgical repair for ATAAD. The underlying mechanisms of this association are important for developing improved prevention strategies.

Effects of TLR3 and TLR9 Signaling Pathway on Brain Protection in Rats Undergoing Sevoflurane Pretreatment during Cardiopulmonary Bypass

OBJECTIVE

To investigate the effects of TLR3 and TLR9 signaling pathway on brain injury during CPB in rats pretreated with sevoflurane and its possible molecular mechanism.

METHODS

SD rats were randomly assigned to sham group, CPB group, and Sev group. Brain tissue was obtained at before CPB (T0), at CPB for 30 minutes (T1), 1 hour after CPB (T3), and 3 hours after CPB (T5). ELISA was used to measure S100-β and IL-6. Western blot was utilized to determine TLR3 and TLR9 expression. TUNEL was applied to detect neuronal apoptosis.

RESULTS

Compared with CPB group, at T1, at termination after 1 hour of CPB (T2), T3, 2 hours after CPB (T4) and T5, S100-β and IL-6 decreased in Sev group. Compared with CPB group, IFN-β were increased in Sev group, except T0. Compared with CPB group, TLR3 expression increased, and TLR9 and NF-κB decreased in Sev group. The apoptotic neurons were less in Sev group than in CPB group (P < 0.05).

CONCLUSION

Sevoflurane intervention can activate TLR3 and TLR9 signaling pathway, upregulate TLR3 expression and downstream TRIF expression, decrease TLR9 expression, and downregulate downstream NF-κB expression in CPB rat models, thereby mitigating brain injury induced by inflammatory response during CPB.

Dexmedetomidine reduces the neuronal apoptosis related to cardiopulmonary bypass by inhibiting activation of the JAK2-STAT3 pathway

Cardiopulmonary bypass (CPB) constitutes one of the primary methodologies pertaining to cardiac surgery. However, this form of surgery can cause damage to the body. Many studies have reported that dexmedetomidine confers cerebral protection. In this study, we aimed to investigate the effect and mechanism of dexmedetomidine on neuronal apoptosis caused by CPB. Here, rats were treated with different doses of dexmedetomidine by intravenous infusion 2 hours after CPB. We observed that dexmedetomidine treatment to rats reduces the S100β, NSE levels in plasma, and neuronal apoptosis following CPB in a dose-dependent manner. Furthermore, we observed that the beneficial effect of dexmedetomidine treatment following CPB was associated with a reduction in IL6, an inflammatory cytokine in plasma and cortex. Our results suggest that dexmedetomidine provides neuroprotective effects by inhibiting inflammation and reducing neuronal apoptosis. There was a correlation between the protective effect on the brain and the dose of dexmedetomidine. In addition, dexmedetomidine administration inhibits phosphorylation of JAK2 and STAT3 proteins in the hippocampus of rats 2 hours after CPB. Therefore, we speculate that the JAK2–STAT3 pathway plays an important role in the neuroprotective effects of dexmedetomidine following brain injury induced by CPB.