Although the treatment of aneurysmal subarachnoid hemorrhage (SAH) has made considerable progress in recent years,its mortality and disability have not been effectively controlled.Ischemic brain injury after SAH is considered to be an important reason for the poor prognosis of patients; however,its mechanism is still not fully understood.Studies have shown that the cerebral microcirculation disturbance after SAH is closely associated with ischemic brain injury.This article reviews the advances in research on cerebral microcirculation disturbance and ischemic brain injury after SAH.

Objective To explore the dynamic changes of blood brain barrier(BBB)permeability after experimental subarachnoid hemorrhage(SAH)in rats.Methods Eighty female SD rats were divided into normal saline control group(n=10)and SAH group(n=70).The SAH model was induced by injecting 300 ?l of autologous arterial blood into the subarachnoid space near the circle of Willis via a cannula in an artificial hole between the olfactory bulb and frontal lobe.BBB permeability in cerebral cortex of SAH and normal saline rats was assessed at 6,12,24,36,48,60,and 72 h after SAH establishment by fluorescence spectrophotometer and fluorescence microscopy for Evans Blue(EB)extravasation.The ultrastructural changes in BBB were observed with transmission electron microscope.Results Compared with the control group,the changes of Evans Blue content and extravasation in cerebral cortex of SAH group peaked at 36 h(P0.05).The severe ultrastructural abnormality was found at 36 h after SAH.Conclusion The changes of BBB permeability develop at the acute stage of SAH,resulting from multiple factors together.The BBB after SAH possesses a self-repairable property.

Objective To evaluate the effect of Levosimendan on the prognosis in patients with severe coronary heart disease after operation.Methods A total of 485 severe coronary disease patients undergoing coronary artery bypass grafting from Teda International Cardiovascular Hospital and the Cardiac Surgery Department of the First Affiliated Hospital of China Medical University from May 2014 to June 2016 were enrolled.Of them,45 cases receiving Levosimendan postoperatively were assigned to the Levosimendan group,and according to propensity score matching,another 45 cases were selected as the control group in this study.Clinical data before treatment had no difference between the groups (P ＞ 0.1).Postoperative prognosis was compared between the two groups.Results There were significant differences in heart rate,mean arterial pressure,central venous pressure,cardiac output and other hemodynamic parameters between the two groups 48h after operation.The heart ultrasound results showed that the left ventricular ejection fraction(IVEF) was increased [(0.53±0.12) ％vs.(0.46±0.09)％,t =2.594,P=0.002],the postoperative ventilation time was reduced [(46.8±11.3) h vs.(58.5±16.3) h,t=-2.031,P=0.045]and the onset of bowel sounds became early [(16.5±5.9) h vs.(18.7±10.1) h,t =1.592,P=0.039]in the levosimendan group than in the control group 48h after operation.The incidences of new-onset acute kidney injury(20 ％ and 40 ％,x2 =6.702,P =0.018),new-onset postoperative atrial fibrillation (15.6％ and 44.4％,x2 =6.156,P =0.023) and perioperative myocardial infarction(11.1 ％ and 33.3％,x2 =6.429,P =0.021) had significant differences between the two groups(P＜0.05),but there was no difference in ICU retention time,1-month mortality after operation,malignant arrhythmia incidence and auxiliary equipment use (P ＞ 0.05).Conclusions Levosimendan can improve the early prognosis of severe coronary disease patients undergoing coronary artery bypass grafting and reduce the occurrence of postoperative organ dysfunction.

Neuronal apoptosis is one of the essential mechanisms of early brain injury after subarachnoid hemorrhage (SAH). Recently, HLY78 has been shown to inhibit apoptosis in tumor cells and embryonic cells caused by carbon ion radiation through activation of the Wnt/β-catenin pathway. This study was designed to explore the anti-apoptotic role of HLY78 in experimental SAH. The results demonstrated that HLY78 attenuated neuronal apoptosis and the neurological deficits after SAH through the activation of low-density lipoprotein receptor-related protein 6 (LRP6), which subsequently increased the level of phosphorylated glycogen synthesis kinase 3 beta (p-GSK3β) (Ser9), β-catenin, and Bcl-2, accompanied by a decrease of p-β-catenin, Bax, and cleaved caspase 3. An LRP6 small-interfering ribonucleic acid reversed the effects of HLY78. In conclusion, HLY78 attenuates neuronal apoptosis and improves neurological deficits through the LRP6/GSK3β/β-catenin signaling pathway after SAH in rats. HLY78 is a promising therapeutic agent to attenuate early brain injury after SAH.

Objective: To explore the clinical application value of mixed reality technology in locating perforator vessels and assisting perforator vessel dissection to harvest anterolateral thigh flaps. Methods: Six patients who needed anterolateral thigh flap repair after resection of oral and maxillofacial tumors were recruited from the Department of Oral and Maxillofacial Surgery of Nanchong Central Hospital from January 2020 to January 2021. Before surgery, the CT angiography data of the lower limbs of the patients carrying the calibration points were imported into the data workstation to perform 3D reconstruction of the perforator vessels and surrounding tissues of the thigh, and the reconstruction results were imported into Microsoft HoloLens 2 glasses. During the operation, calibration was performed at the calibration point of the operative area so that the preoperative reconstruction results were superimposed on the operative area through Microsoft HoloLens 2 glasses. The clinical application value of mixed reality technology assisted perforator vessel location and anatomy of anterolateral femoral perforator flap was discussed from six aspects: whether the perforator vessel was reconstructed preoperatively, intraoperative calibration time, whether the actual position of the perforating vessels passing through the fascia lata fulcrum deviated from the preoperative reconstruction result within 1 cm, time required to harvest the flap, and whether the actual route of the perforator vessel was consistent with the reconstruction result, and whether the postoperative flap survived. Results : The position and course of perforating vessels were successfully reconstructed in 6 cases before the operation. The actual course of perforating vessels during the operation was consistent with the reconstruction results. The deviation between the actual position of the perforating points and the preoperative reconstruction results was within 1 cm, which met the requirements of the actual asisting of the anterolateral thigh flap. The average time of flap harvest was (70.50 ± 7.20) min. The average calibration time was (13.33 ± 5.50) min. All flaps survived. Conclusions Mixed reality technology projects the reconstruction results of anterolateral femoral perforator vessels directly into the operative area, which provides a new method for asisting localization and anatomy of anterolateral femoral flap perforator vessels and reduces the possibility of injury to perforator vessels.