Clinical Analysis of Embryonic Posterior Cerebral Artery

Objective:To understand the clinical characteristics of patients with embryonic posterior cerebral artery and its correlation with abnormal vascular development.Methods:The clinical data of 396 patients with embryonic posterior cerebral artery confirmed by magnetic resonance angiography(MRA)and computed tomography angiography(CTA)were analyzed.Results:Two-hundred patients had clinical manifestations of posterior circulation ischemia,including recurrent dizziness,vertigo,and tinnitus;45 had headaches,97 had limb weakness,and 16 patients had syncope or impaired consciousness.Seventy-six patients with circulatory infarction were admitted to the hospital.There were 251 patients with history of hypertension,74 with diabetes,113 with hyperlipidemia,13 with dominant vertebral artery,10 with intracranial aneurysm,and 19 with absence of A1 segment of the anterior cerebral artery(considering developmental variation).Conclusion:Embryonic posterior cerebral artery develops abnormally during the embryonic period,often accompanied by abnormal vascular access.Due to abnormal hemodynamics,the incidence of posterior circulation ischemia,aneurysm,and infarction increases in such patients.

Relationship between ultrasound parameters of the umbilical and middle cerebral arteries and intrauterine fetal distress

BACKGROUND By comprehensively analyzing the blood flow parameters of the umbilical and middle cerebral arteries,doctors can more accurately identify fetal intrauterine distress,as well as assess its severity,so that timely interventions can be implemented to safeguard the health and safety of the fetus.AIM To identify the relationship between ultrasound parameters of the umbilical and middle cerebral arteries and intrauterine distress.METHODS Clinical data of pregnant women admitted between January 2021 and January 2023 were collected and divided into the observation and control groups(n=50 each),according to the presence or absence of intrauterine distress.The ultrasound hemodynamic parameters of the uterine artery(UtA),fetal middle cerebral artery(MCA),and umbilical artery(UmA)were compared with neonatal outcomes and occurrence of intrauterine distress in the two groups.RESULTS Comparison of ultrasonic hemodynamic parameters,resistance index(RI),pulsatility index(PI),and systolic maximal blood flow velocity of UmA compared to diastolic blood flow velocity(S/D),revealed higher values of fetal MCA,PI,and S/D of UmA in pregnant women with UtA compared to controls(P<0.05),while there was no difference between the two groups in terms of RI(P<0.05)The incidence of a neonatal Apgar score of 8-10 points was lower in the observation group(66.7%)than in the control group(90.0%),and neonatal weight(2675.5±27.6 g)was lower than in the control group(3117.5±31.2 g).Further,cesarean section rate was higher in the observation group(70.0%)than in the control group(11.7%),and preterm labor rate was higher in the observation group(40.0%)than in the control group(10.0%).The incidence of fetal distress,neonatal growth restriction and neonatal asphyxia were also higher in the observation group(all P<0.05).CONCLUSION Fetal MCA,UmA,and maternal UtA hemodynamic abnormalities all develop in pregnant women with intrauterine distress during late pregnancy,which suggests that clinical attention should be paid to them,and monitoring should be strengthened to provide guidance for clinical intervention.

Endovascular treatment of ruptured lobulated anterior communicating artery aneurysms:A retrospective study of 24 patients

BACKGROUND Lobulated intracranial aneurysm is a special type of aneurysm with at least one additional cyst in the neck or body of the aneurysm.Lobulated intracranial aneurysm is a complex aneurysm with complex morphology and structure and weak tumor wall,which is an independent risk factor for rupture and hemorrhage.Lobular aneurysms located in the anterior communicating artery complex account for 36.9%of all intracranial lobular aneurysms.Due to its special anatomical structure,both craniotomy and endovascular treatment are more difficult.Compared with single-capsule aneurysms,craniotomy for lobular intracranial aneurysms has a higher risk and complication rate.AIM To investigate the efficacy and safety of endovascular treatment for ruptured lobulated anterior communicating artery aneurysm(ACoAA).METHODS Patients with ruptured lobulated ACoAA received endovascular treatment in Sanming First Hospital Affiliated to Fujian Medical University from June 2020 to June 2022 were retrospectively included.Their demographic,clinical and imaging characteristics,endovascular treatment methods and follow-up results were collected.RESULTS A total of 24 patients with ruptured lobulated ACoAA were included,including 9 males(37.5%)and 15 females(62.5%).Their age was 56.2±8.9 years old(range 39-74).The time from rupture to endovascular treatment was 10.9±12.5 h.The maximum diameter of the aneurysms was 5.1±1.0 mm and neck width were 3.0±0.7 mm.Nineteen patients(79.2%)were double-lobed and 5(20.8%)were multilobed.Fisher's grade:Grade 2 in 16 cases(66.7%),grade 3 in 6 cases(25%),and grade 4 in 2 cases(8.3%).Hunt-Hess grade:Grade 0-2 in 5 cases(20.8%),grade 3-5 in 19 cases(79.2%).Glasgow Coma Scale score:9-12 in 14 cases(58.3%),13-15 in 10 cases(41.7%).Immediately postprocedural Raymond-Roy grade:grade 1 in 23 cases(95.8%),grade 2 in 1 case(4.2%).Raymond-Roy grade in imaging follow-up for 2 wk to 3 months:grade 1 in 23 cases(95.8%),grade 2 in 1 case(4.2%).Followup for 2 to 12 months showed that 21 patients(87.5%)had good functional outcomes(modified Rankin Scale score≤2),and there were no deaths.CONCLUSION Endovascular treatment is a safe and effective treatment for ruptured lobulated AcoAA.

Therapeutic effects of different durations of acupuncture on rats with middle cerebral artery occlusion

Acupuncture is regarded as an effective therapy for cerebral ischemia. Different acupuncture ma- nipulations and durations may result in different therapeutic effects. In the present study, the Neig uan （PC6） acupoint of rats with occluded middle cerebral arteries was needled at a fixed frequency （3 Hz） with different durations, i.e., 5, 60 and 180 seconds under a twisting-rotating acupuncture method. Results showed that different durations of acupuncture had different therapeutic effects, with 60 seconds yielding a better therapeutic effect than the other two groups. This duration of treatment demonstrated rapid cerebral blood flow, encouraging recovery of neurological function, and small cerebral infarct volume. Experimental findings indicated that under 3 Hz frequency, the treatment of needling Neiguan for 60 seconds is effective for ischemic stroke.

Predictors of short-term outcome in patients with acute middle cerebral artery occlusion: unsuitability of fluid-attenuated inversion recovery vascular hyperintensity scores

Fluid-attenuated inversion recovery （FLAIR） vascular hyperintensity （FVH） is used to assess leptomeningeal collateral circulation, but clinical outcomes of patients with FVH can be very different. The aim of the present study was to assess a FVH score and explore its relationship with clinical outcomes. Patients with acute ischemic stroke due to middle cerebral artery M1 occlusion underwent magnetic resonance imaging and were followed up at 10 days （National Institutes of Health Stroke Scale） and 90 days （modified Rankin Scale） to determine short-term clinical outcomes. Effective collateral circulation indirectly improved recovery of neurological function and short-term clinical outcome by extending the size of the pial penumbra and reducing infarct lesions. FVH score showed no correlation with 90-day functional clinical outcome and was not sufficient as an independent predictor of short-term clinical outcome.

In vivo tracking of human adipose-derived stem cells labeled with ferumoxytol in rats with middle cerebral artery occlusion by magnetic resonance imaging

Ferumoxytol, an iron replacement product, is a new type of superparamagnetic iron oxide ap- proved by the US Food and Drug Administration. Herein, we assessed the feasibility of tracking transplanted human adipose-derived stem cells labeled with ferumoxytol in middle cerebral artery occlusion-injured rats by 3.0 T MRI in vivo. 1 × 104 human adipose-derived stem cells labeled with ferumoxytol-heparin-protamine were transplanted into the brains of rats with middle cerebral artery occlusion. Neurologic impairment was scored at 1, 7, 14, and 28 days after transplantation. T2-weighted imaging and enhanced susceptibility-weighted angiography were used to observe transplanted cells. Results of imaging tests were compared with results of Prussian blue staining. The modified neurologic impairment scores were significantly lower in rats transplanted with cells at all time points except I day post-transplantation compared with rats without transplantation. Regions with hypointense signals on T2-weighted and enhanced susceptibility-weighted angiography images corresponded with areas stained by Prussian blue, suggesting the presence of superparamagnetic iron oxide particles within the engrafted cells. Enhanced susceptibility-weighted angiography image exhibited better sensitivity and contrast in tracing ferumoxytol-heparin-protamine-labeled human adipose-derived stem ceils compared with T2-weighted imaging in routine MRI.

Screen-imaging guidance using a modified portable video macroscope for middle cerebral artery occlusion

The use of operating microscopes is limited by the focal length.Surgeons using these instruments cannot simultaneously view and access the surgical field and must choose one or the other.The longer focal length （more than 1 000 mm） of an operating telescope permits a position away from the operating field,above the surgeon and out of the field of view.This gives the telescope an advantage over an operating microscope.We developed a telescopic system using screen-imaging guidance and a modified portable video macroscope constructed from a Computar MLH-10 × macro lens,a DFK-21AU04 USB CCD Camera and a Dell laptop computer as monitor screen.This system was used to establish a middle cerebral artery occlusion model in rats.Results showed that magnification of the modified portable video macroscope was appropriate （5-20 ×） even though the Computar MLH-10 × macro lens was placed 800 mm away from the operating field rather than at the specified working distance of 152.4 mm with a zoom of 1-40 ×.The screen-imaging telescopic technique was clear,life-like,stereoscopic and matched the actual operation.Screen-imaging guidance led to an accurate,smooth,minimally invasive and comparatively easy surgical procedure.Success rate of the model establishment evaluated by neurological function using the modified neurological score system was 74.07%.There was no significant difference in model establishment time,sensorimotor deficit and infarct volume percentage.Our findings indicate that the telescopic lens is effective in the screen surgical operation mode referred to as ＂long distance observation and short distance operation＂ and that screen-imaging guidance using an modified portable video macroscope can be utilized for the establishment of a middle cerebral artery occlusion model and micro-neurosurgery.

Effect of Fujian tablet on the expression of Nogo-A mRNA in the cervical spinal cord of middle cerebral artery occlusion model rats

Inhibiting the expression of Nogo-A in cervical spinal cord by use of interaction of antigen and antibody can help the remodeling of corticospinal projection of focal cerebral ischemia model rats to facilitate neurological recovery, which provides a new possible mechanism for drugs to promote neurological recovery. However, the effects of drugs on the expression of Nogo-A in cervical spinal cord are still unclear. OBJECTIVE： To observe the effect of Fujian tablet on the expression of Nogo-A mRNA in cervical spinal cords of middle cerebral artery occlusion （MCAO） rats, and to investigate the possible regulatory effect of Fujian tablet on the regenerated microenvironment of spinal conduction bundle. DESIGN： A randomized and controlled trial taking Wistar rats as experimental animals. SETTING： Department of Neurology, Affiliated Hospital of Shandong University of Traditional Chinese Medicine. MATERIALS： This experiment was carried out in the laboratory of Shandong Academy of Medical Science between June 2005 and July 2006. A total of 40 healthy male Wistar rats, aged 12 weeks, weighing 250 - 300 g, were provided by the Experimental Animal Center of Shandong University. Fujian tablets （main components： Heshouwu, Yinyanghuo, etc） were provided by office of Pharmaceutics of Shandong University of traditional Chinese medicine. Nogo-A detection kit was provided by Wuhan Boster Biotechnology Co.,Ltd., and batch number was 040309009. This experiment was approved by Local Animal Ethics Committee. METHODS： Forty male rats were randomly divided into 4 groups, with 10 in each： normal group, sham-operation group, model group and administration group. Rats in the administration group and model group were subjected to MCAO. Rats in the sham-operation group underwent the same craniotomy, and their middle cerebral arteries （MCA） were not occluded. Rats in the normal group were untouched. Rats in administration group were intragastrically administrated with the solution of Fujian tablet at a dose of 9 g/kg and others were given equal dosage of normal saline two days later. The treatments were done once a day and the course totaled 2 weeks. MAIN OUTCOME MEASURES： The expression of Nogo-A mRNA in slices of cervical spinal cords. RESULTS： Forty rats were involved in the final analysis. The expression of Nogo-A mRNA in the cervical spinal cord of rats in the administration group and model group was significantly decreased as compared with that in the normal group （P 〈 0.01 and P 〈 0.05, respectively）. The expression of Nogo-A mRNA in the administration group was also significantly weaker than that in the model group （P 〈 0.05 ） . CONCLUSION： Fujian tablet can inhibit the expression of Nogo-A mRNA in cervical spinal cords of MCAO rats, which facilitates regeneration and remodeling of cervical spinal cords.

Motor outcomes of patients with a complete middle cerebral artery territory infarct

Detailed knowledge of motor outcomes enables to establish proper goals and rehabilitation strate-gies for stroke patients. Several previous studies have reported functional or motor outcomes in patients with a middle cerebral artery territory infarct. However, little is known about motor outcome in patients with a complete middle cerebral artery territory infarct. In this study, we investigated the motor outcomes in 23 patients with a complete middle cerebral artery territory infarct. All of these patients received comprehensive rehabilitative management, including movement therapy and neuromuscular electrical stimulation of the affected finger extensors and ankle dorsiflexors, for more than 3 months. Motor outcomes were measured at 6 months after stroke onset using the Medical Research Council, Motricity Index, the modified Brunnstrom Classification, and Functional Ambula-tion Category scores. The motor function of the lower extremities was found to be better than that of the upper extremities. After receiving rehabilitation treatments for 3–6 months, about 70% of these patients were able to walk independently （Functional Ambulation Category scores 3）, but no pa-tient achieved functional hand recovery.

Viscoelastic evaluation of fetal umbilical vein for reconstruction of middle cerebral artery

The transplantation of artificial blood vessels with 〈 6 mm inner diameter as substitutes for human arterioles or veins has not achieved satisfactory results. Umbilical vein has been substituted for ar- tery in vascular transplantation, but it remains unclear whether the stress relaxation and creep be- tween these vessels are consistent. In this study, we used the fetal umbilical vein and middle cere- bral artery from adult male cadavers to make specimens 15 mm in length, 0.196-0.268 mm in tu- nica media thickness, and 2.82-2.96 mm in outer diameter. The results demonstrated that the stress decrease at 7 200 seconds was similar between the middle cerebral artery and fetal umbilical vein specimens, regardless of initial stress of 18.7 kPa or 22.5 kPa. However, the strain increase at 7 200 seconds of fetal umbilical veins was larger than that of middle cerebral arteries. Moreover, the stress relaxation experiment showed that the stress decrease at 7 200 seconds of the fetal umbilical vein and middle cerebral artery specimens under 22.5 kPa initial stress was less than the decrease in these specimens under 18.7 kPa initial stress. These results indicate that the fetal umbilical vein has appropriate stress relaxation and creep properties for transplantation. These properties are advantageous for vascular reconstruction, indicating that the fetal umbilical vein can be transplanted to repair middle cerebral artery injury.

Surgical Treatment of Poor Grade Middle Cerebral Artery Aneurysms Associated with Large Sylvian Hematomas Following Prophylactic Hinged Craniectomy

The clinical characteristics of patients who presented in poor clinical grade due to ruptured middle cerebral artery aneurysms （MCAAs） associated with large sylvian hematomas （SylH） were ana- lyzed and an ingenious designed prophylactic hinged craniectomy was introduced. Twenty-eight pa- tients were graded into Hunt-Hess grades IV-V and emergency standard micro-neurosurgeries （aneu- rysm clipping, hematoma evacuation and prophylactic hinged craniectomy） were performed, and their clinical data were retrospectively analyzed. 46.43% of the patients reached encouraged favorable out- comes on discharge. The favorable outcome group and the poor outcome group significantly differed in terms of patients＇ anisocoria, Hunt-Hess grade before surgery, extent of the midline shift and time to the surgery after bleeding （P〈0.05）. There were no significant differences in age, sex, volume and location of the hematoma, size of aneurysm between the favorable and poor groups （P〉0.05）. However, ingen- ious designed prophylactic hinged craniectomy efficiently reduced the patients＇ intracranial pressure （ICP） after surgery. It was suggested that preoperative conditions such as Hunt-Hess grading, extent of the midline shift and the occurrence of cerebral hernia affect the prognosis of patients, but time to the surgery after bleeding and prophylactic hinged craniectomy are of significant importance for optimizing the prognosis ofMCAA oatients 19resenting with large SylH.

Apparent diffusion coefficient evaluation for secondary changes in the cerebellum of rats after middle cerebral artery occlusion

Supratentorial cerebral infarction can cause functional inhibition of remote regions such as the cerebellum, which may be relevant to diaschisis. This phenomenon is often analyzed using positron emission tomography and single photon emission CT. However, these methods are expensive and radioactive. Thus, the present study quantified the changes of infarction core and remote regions after unilateral middle cerebral artery occlusion using apparent diffusion coefficient values. Diffu- sion-weighted imaging showed that the area of infarction core gradually increased to involve the cerebral cortex with increasing infarction time. Diffusion weighted imaging signals were initially in- creased and then stabilized by 24 hours. With increasing infarction time, the apparent diffusion co- efficient value in the infarction core and remote bilateral cerebellum both gradually decreased, and then slightly increased 3-24 hours after infarction. Apparent diffusion coefficient values at remote regions （cerebellum） varied along with the change of supratentorial infarction core, suggesting that the phenomenon of diaschisis existed at the remote regions. Thus, apparent diffusion coefficient values and diffusion weighted imaging can be used to detect early diaschisis.

Effects of Echinacoside on Histio-central Levels of Active Mass in Middle Cerebral Artery Occlusion Rats

Objective To investigate the effects of echinacoside on the extracellular striatal levels of norepinephrine（NE）,dopamine（DA）,homovanillic acid（HVA）,3,4-dihydroxyphenylethanoid acid（DOPAC）,5-hydroxyindoleacetic acid（HIAA）,and 5-hydroxytryptamine（5-HT） in middle cerebral artery occlusion（MCAO rats.Methods The middle cerebral artery was occluded in male Sprague-Dawley rats.Three days later microdialysis probes were placed into the right striatum of MCAO rat brains and the brains were perfused with Ringer＇s solution at a rate of 1.5 μL/min.Cerebral microdialysates were collected every 30 minutes from awake and freely moving rats before assaying for NE,DA,HVA,DOPAC,HIAA,and 5-HT levels by reverse phase HPLC with electrochemistry.Results Three days after MCAO,the extracellular striatal levels of NE,DA,DOPAC,HIAA,HVA,and 5-HT of the MCAO rats increased significantly（at least P0.05 vs.control）.However,simultaneous treatment with echinacoside（30.0 or 15.0 mg/kg） attenuated these increases（at least P0.05 vs.non-treated model rats）.Conclusion These results imply that echinacoside may protect striatal dopa minergic neurons from the injury induced by MCAO and may help prevent and treat cerebral ischemic diseases.

Establishment of a rhesus monkey model of middle cerebral artery ischemia and reperfusion using a microcatheter embolization method

Nonhuman primates are closest to humans in terms of lineage, and middle cerebral artery ischemia/reperfusion responses of nonhuman primates are most similar to ischemic stroke in humans. Therefore, nonhuman primates could be utilized to simulate the process of ischemic stroke in the human. Few studies, however, have reported the use of endovascular technology to establish a rhesus monkey stroke model. In the present study, seven adult, male, rhesus monkeys were selected and, following anesthesia, a microcatheter was inserted into one side of the middle cerebral artery via the femoral artery to block blood flow, thereby resulting in middle cerebral artery occlusion. After 2 hours, the microcatheter was withdrawn to restore the middle cerebral artery blood flow and to establish ischemia/reperfusion. Results from angiography and magnetic resonance angiography confirmed occlusion and reopening of the middle cerebral artery. Magnetic resonance imaging revealed the existence of ischemic brain lesions, and neurological examination showed sustained functional deficits following surgery. The rhesus monkey middle cerebral artery ischemia/reperfusion models established by microcatheter embolization had the advantage of non-craniotomy invasion and reproducibility. The scope and degree of ischemic damage using this model was controllable. Therefore, this nonhuman primate model is an ideal model for cerebral ischemia and reperfusion.

Neuroprotective effect of Longshengzhi capsule following permanent middle cerebral artery occlusion in rats

Objective:Longshengzhi capsule(LSZC)is an optimized preparation based on the traditional Chinese Medicine formula Buyanghuanwu Decoction(BYHWD),and is approved by the China Food and Drug Administration for treating stroke-induced disability and vascular diseases.Herein,we examined the pharmacodynamics,anti-apoptotic and anti-oxidant actions,and potential mechanisms of action of LSZC following stroke in rats.Methods:Permanent middle cerebral artery occlusion(MCAO)was used as an ischemic stroke model.LSZC was administered intragastrically.We examined the survival rate,bodyweight,and neurological deficits in stroke rats.Brain infarct size was determined by 2,3,5-triphenyltetrazolium chloride staining.Brain pathology was examined using hematoxylin and eosin staining,Nissl staining,and TdT-mediated dUTP Nick-End Labeling staining.Malondialdehyde,catalase,superoxide dismutase,and glutathione levels were examined by commercial kits.Expression of Nrf2,heme oxygenase-1,Bax,Bcl-2,cleaved caspase-3,and caspase-3 proteins in brain tissue was measured by Western blot.Results:LSZC markedly improved the survival rate and bodyweight,and reduced infarct volume and neurological deficit scores,in MCAO stroke rats.LSZC also significantly attenuated oxidative stress,as indicated by decreased expression of malondialdehyde,and upregulation of Nrf2,heme oxygenase-1,catalase,superoxide dismutase,and glutathione.Moreover,LSZC significantly decreased apoptosis,including a decrease in Bax and cleaved caspase-3 expression,and an increase in Bcl-2,as well as a reduction in numbers of apoptotic neurons.Conclusion:LSZC treatment is neuroprotective against ischemic stroke,potentially via reducing oxidative stress and apoptosis.The Nrf2 and apoptotic signaling pathways may play important roles in the antioxidant and anti-apoptotic actions of LSZC.

Significance of Cyclooxygenase-2 Elevation in Middle Cerebral Artery for Patients with Hemorrhagic Moyamoya Disease

The etiology and pathogenesis of moyamoya disease（MMD） remain elusive. Some inflammatory proteins, such as cyclooxygenase（COX）-2, are believed to be implicated in the development of MMD. So far, the relationship between COX-2 and MMD is poorly understood and reports on the intracranial vessels of MMD patients are scanty. In this study, tiny pieces of middle cerebral artery（MCA） and superficial temporal artery（STA） from 13 MMD patients were surgically harvested. The MCA and STA samples from 5 control patients were also collected by using the same technique. The expression of COX-2 was immunohistochemically detected and the average absorbance（A） of positively-stained areas was measured. High-level COX-2 expression was found in all layers of the MCA samples from all 5 hemorrhagic MMD patients, while positive but weak expression of COX-2 was observed only in the endothelial layer of the MCA samples from most ischemic MMD patients（6/8, 75%）. The average A values of COX-2 in the hemorrhagic MMD patients were substantially higher than those in their ischemic counterparts（t=4.632, P=0.001）. There was no significant difference in the COX-2 expression among the ＂gender＂ groups, or ＂radiographic grade＂ groups, or ＂lesion location＂ groups（P0.05 for all）. The COX-2 expression was detected neither in the MCA samples from the controls nor in all STA specimens. Our results suggested that COX-2 was up-regulated in the MCA of MMD patients, especially in hemorrhagic MMD patients. We are led to speculate that COX-2 may be involved in the pathogenesis of MMD and even contribute to the hemorrhagic stroke of MMD patients.

Fetal umbilical vein transplantation for the repair of middle cerebral artery injury

It is necessary to investigate the longitudinal tensile mechanical characteristics of the middle cere- bral artery and the fetal umbilical vein prior to applying fetal umbilical vein transplantation for repair of injured middle cerebral artery. Fifteen fresh fetal umbilical vein specimens and 15 normal human fresh cadaver middle cerebral artery specimens were collected for longitudinal tensile testing at the speed of 0.5 mm/min and at normal human temperature. The results showed that under 16.0 kPa physiological stress, the strain value of fetal umbilical vein specimens was larger, while the maximal stress and elastic modulus values were less than those of middle cerebral artery specimens. Our findings indicate that fetal umbilical vein has good elastic properties and the stress-strain curve of the fetal umbilical vein is similar to that of the middle cerebral artery. Fetal umbilical vein transplan- tation can, therefore, potentially repair the injured middle cerebral artery.

Intraoperative hemodynamic parameters of middle cerebral artery and other artery aneurysms utilizing transcranial Doppler ultrasonography

BACKGROUND： Hemodynamic changes accompany the initiation, development and rupture of middle cerebral artery （MCA） aneurysms. The complexity of the intraaneurysmal hemodynamic factors has not been completely clarified by the indirect measures and methods used in previous studies. OBJECTIVE： To evaluate correlations of intraoperative hemodynamic factors to initiation and rupture of MCA aneurysms. DESIGN, TIME AND SETTING： A case-control study was performed at the Department of Neurosurgery, Tiantan Hospital Affiliated to Capital Medical University, China between March and October 2008. PARTICIPANTS： A total of 12 consecutive patients diagnosed with MCA aneurysms （MCA aneurysms group） and five patients without middle cerebral artery aneurysms （with aneurysms located at other arteries, control group） were enrolled at the Department of Neurosurgery, Tiantan Hospital Affiliated to Capital Medical University, China. METHODS： The proximal and distal arteries of MCA aneurysms were exposed visibly in the MCA aneurysm group. The M1 segment of MCA without the aneurysm and the aneurysm on other arteries were also exposed visibly in the control group. Hemodynamic indices were then measured using an intraoperative 16 MHz probe installed in a Multi-Dop TCD8X4 device. MAIN OUTCOME MEASURES： Mean （time-averaged velocity） difference, maximum mean, pulsatility index difference, maximum pulsatility index, resistance index difference, maximum resistance index; correlation of development and rupture of MCA aneurysms to intraoperative hemodynamic factors of the parent artery. RESULTS： A total of 12 patients underwent microsurgery for treatment to occlude 15 MCA aneurysms. Of the 15 MCA aneurysms, 12 were located at the bifurcation, two at the M1 segment and one at the M3 segment; eight of the aneurysms were unruptured and seven were ruptured. The whole indices with combination mean difference, maximum mean, and maximum pulsatility index of the aneurysms were important factors influencing the rupture of MCA aneurysms （t = 2.92, P = 0.03, constant）. A higher velocity intraaneurismal flow at the bifurcation was identified （t = 3.48, P = 0.01, constant）. After the aneurysm was completely occluded, global high-velocity flow could not be detected in the parent arteries （t = 2.57, P=0.03, constant）. CONCLUSION： When short-term high-velocity blood flow is present, aneurysms can be easily initiated and ruptured at the bifurcation of MCA.

Occlusion of the middle cerebral artery Guidance by screen imaging using an EDA-H portable medium-soft electronic endoscope

The present study aimed to verify the practicability of performing screen-based surgical operations under the guidance of a real-time viewing and recording system （RTVRS） using a portable medium-soft electronic endoscope （pmsEE）. The middle cerebral artery in rats was occluded under screen-imaging guidance using a pmsEE RTVRS to reproduce an animal model of human cerebral infarction. The screen imaging of the pmsEE RTVRS was clear, life-like, stereoscopic and synchronous with the actual operation. Screen-imaging guidance led to an accurate, smooth, minimally invasive and comparatively easy surgical procedure. The surgical success rate, time of model establishment, neurological function scores, and infarct volume were similar to those using an operating microscope. These results indicate that the self-designed pmsEE RTVRS could be utilized for portable endoscopic screen-based surgical operations.

Middle cerebral artery occlusion methods in rat versus mouse model of transient focal cerebral ischemic stroke

Experimental stroke research commonly employs focal cerebral ischemic rat models （Bederson et al., 1986a; Longa et al., 1989）. In human patients, ischemic stroke typically results from thrombotic or embolic occlusion of a major cerebral artery, usually the mid- dle cerebral artery （MCA）. Experimental focal cerebral ischemia models have been employed to mimic human stroke （Durukan and Tatlisumak, 2007）. Rodent models of focal cerebral ischemia that do not require craniotomy have been developed using intraluminal suture occlusion of the MCA （MCA occlusion, MCAO） （Rosamond et al., 2008）. Furthermore, mouse MCAO models have been wide- ly used and extended to genetic studies of cell death or recovery mechanisms （Liu and McCullough, 2011）. Genetically engineered mouse stroke models are particularly useful for evaluation of isch- emic pathophysiology and the design of new prophylactic, neuro- protective, and therapeutic agents and interventions （Armstead et al., 2010）. During the past two decades, MCAO surgical techniques have been developed that do not reveal surgical techniques for mouse MCAO model engineering. Therefore, we compared MCAO surgical methods in rats and mice.