Differences and Correlations of Morphological and Hemodynamic Parameters between Anterior Circulation Bifurcation and Side-wall Aneurysms

Objective:The objective of this research was to explore the difference and correlation of the morphological and hemodynamic features between sidewall and bifurcation aneurysms in anterior circulation arteries,utilizing computational fluid dynamics as a tool for analysis.Methods:In line with the designated inclusion criteria,this study covered 160 aneurysms identified in 131 patients who received treatment at Union Hospital of Tongji Medical College,Huazhong University of Science and Technology,China,from January 2021 to September 2022.Utilizing follow-up digital subtraction angiography(DSA)data,these cases were classified into two distinct groups:the sidewall aneurysm group and the bifurcation aneurysm group.Morphological and hemodynamic parameters in the immediate preoperative period were meticulously calculated and examined in both groups using a three-dimensional DSA reconstruction model.Results:No significant differences were found in the morphological or hemodynamic parameters of bifurcation aneurysms at varied locations within the anterior circulation.However,pronounced differences were identified between sidewall and bifurcation aneurysms in terms of morphological parameters such as the diameter of the parent vessel(Dvessel),inflow angle(θF),and size ratio(SR),as well as the hemodynamic parameter of inflow concentration index(ICI)(P<0.001).Notably,only the SR exhibited a significant correlation with multiple hemodynamic parameters(P<0.001),while the ICI was closely related to several morphological parameters(R>0.5,P<0.001).Conclusions:The significant differences in certain morphological and hemodynamic parameters between sidewall and bifurcation aneurysms emphasize the importance to contemplate variances in threshold values for these parameters when evaluating the risk of rupture in anterior circulation aneurysms.Whether it is a bifurcation or sidewall aneurysm,these disparities should be considered.The morphological parameter SR has the potential to be a valuable clinical tool for promptly distinguishing the distinct rupture risks associated with sidewall and bifurcation aneurysms.

The incidence rate and histological characteristics of intimal hyperplasia in elastase-induced experimental abdominal aortic aneurysms in mice

Intimal hyperplasia(IH)is a negative vascular remodeling after arterial injury.IH occasionally occurs in elastase-induced abdominal aortic aneurysm(AAA)mouse models.This study aims to clarify the incidence and histological characteristics of IH in aneurysmal mice.A retrospective study was conducted by including 42 male elastaseinduced mouse AAA models.The IH incidence,aortic diameters with or without IH,and hyperplasia lesional features of mice were analyzed.Among 42 elastase-induced AAA mouse models,10 mice developed mild IH(24%)and severe IH was found in only 2 mice(5%).The outer diameters of the AAA segments in mice with and without IH did not show significant difference.Both mild and severe IH lesions show strong smooth muscle cell positive staining,but endothelial cells were occasionally observed in severe IH lesions.There was obvious macrophage infiltration in the IH lesions of the AAA mouse models,especially in mice with severe IH.However,only a lower numbers of T cells and B cells were found in the IH lesion.Local cell-secreted matrix metalloproteinases(MMP)2 was highly expressed in all IH lesions,but MMP9 was only overexpressed in severe lesions.In conclusion,this study is the first to demonstrate the occurrence of aneurysmal IH and its histological characteristics in an elastaseinduced mouse AAA model.This will help researchers better understand this model,and optimize it for use in AAA-related research.

Knowledge domain and emerging trends in the rupture risk of intracranial aneurysms research from 2004 to 2023

BACKGROUND Intracranial aneurysms(IAs)pose significant health risks,attributable to their potential for sudden rupture,which can result in severe outcomes such as stroke and death.Despite extensive research,the variability of aneurysm behavior,with some remaining stable for years while others rupture unexpectedly,remains poorly understood.AIM To employ bibliometric analysis to map the research landscape concerning risk factors associated with IAs rupture.METHODS A systematic literature review of publications from 2004 to 2023 was conducted,analyzing 3804 documents from the Web of Science Core Collection database,with a focus on full-text articles and reviews in English.The analysis encompassed citation and co-citation networks,keyword bursts,and temporal trends to delineate the evolution of research themes and collaboration patterns.Advanced software tools,CiteSpace and VOSviewer,were utilized for comprehensive data visualization and trend analysis.RESULTS Analysis uncovered a total of 3804 publications on IA rupture risk factors between 2006 and 2023.Research interest surged after 2013,peaking in 2023.The United States led with 28.97%of publications,garnering 37706 citations.Notable United States-China collaborations were observed.Capital Medical University produced 184 publications,while Utrecht University boasted a citation average of 69.62 per publication.“World Neurosurgery”published the most papers,contrasting with“Stroke”,the most cited journal.The PHASES score from“Lancet Neurology”emerged as a vital rupture risk prediction tool.Early research favored endovascular therapy,transitioning to magnetic resonance imaging and flow diverters.CONCLUSION This study assesses global IA research trends and highlights crucial gaps,guiding future investigations to improve preventive and therapeutic approaches.

Giant cavernous aneurysms occluded by aneurysmal thrombosis,calcification,parent artery occlusion:A case report and review of literature

BACKGROUND Patients with giant intracranial aneurysms(GIAs)are at a high risk of rupture,morbidity,and mortality even after surgical or endovascular treatment.We described a case of a spontaneously occluded GIA secondary to gradual growth of the GIA,continuously progressed aneurysmal thrombosis,complete aneurysmal calcification and complete occlusion of the parent artery-the right internal carotid artery(RICA).CASE SUMMARY A 72-year-old female patient complained of sudden pain in her right eye upon admission to our hospital.She had been diagnosed with a GIA[30 mm(axial)×38 mm(coronal)×28 mm(sagittal)]containing an aneurysmal thrombus located in the cavernous sinus segment of RICA diagnosed by magnetic resonance imaging(MRI),enhanced MRI,and magnetic resonance angiography more than 14 years ago.Later,with slow growth of the cavernous carotid GIA,aneurysmal thrombosis progressed continuously,spontaneous occlusion of the RICA,complete aneurysmal calcification,and occlusion of the GIA occurred gradually.She had no history of subarachnoid hemorrhage but missed the chance for endovascular therapy at an early stage.As a result,she was left with severe permanent sequelae from the injuries to the right cranial nerves Ⅱ,Ⅲ,Ⅳ,V1/V2,and Ⅴ.CONCLUSION The risk of rupture of the cavernous carotid GIAs was relatively low and possibly further be reduced by the stasis flow and spontaneous occlusion of the parent artery internal carotid artery(ICA)induced by the mass effect of the cavernous carotid GIAs and the extremely rare aneurysmal calcification.However,nowadays,it is advisable to recommend early endovascular treatment for the cavernous carotid GIAs to prevent injuries to the surrounding intracranial nerves and occlusion of the ICA,mainly caused by the mass effect of the cavernous carotid GIAs.

An unusual etiology of subarachnoid hemorrhage,basilar artery perforator aneurysms,in Macao:Three case reports and review of literature

BACKGROUND Subarachnoid hemorrhage is a severe neurological condition that requires prompt and appropriate treatment to prevent complications.Aneurysms are the most common cause of spontaneous subarachnoid hemorrhage.Conversely,basilar artery perforator aneurysms(BAPAs)are a rare etiology.There is no consensus on the optimal management of ruptured BAPAs in the acute setting.CASE SUMMARY We present a case series of 3 patients with ruptured BAPAs who were treated at our institution.Two patients had a modified Fisher grade of I,and one had a grade of IV on initial presentation.The aneurysms were detected by computed tomography angiography in two cases and conventional angiography in one case.The 3 patients underwent endovascular treatment with Guglielmi detachable coils.Post-treatment,the patients had good clinical outcomes,and follow-up brain computed tomography scans showed reduced subarachnoid hemorrhage without any new hemorrhage.However,one patient experienced a cerebral infarction 2 months later and eventually succumbed to the condition.The other 2 patients showed progressive recovery,and no aneurysm recurrence was observed at the 2-year follow-up.CONCLUSION Endovascular treatment may be a preferable approach for managing ruptured BAPAs compared with surgical intervention or conservative management.Early detection and prompt treatment is important to achieve favorable patient outcomes.

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.

Safety and Efficacy of Endovascular Aortic Repair for Abdominal Aortic Aneurysms with a Hostile Neck Anatomy

Objective This study aimed to investigate the safety and efficacy of endovascular aortic repair(EVAR)for the treatment of an abdominal aortic aneurysm(AAA)with a hostile neck anatomy(HNA).Methods From January 1,2015 to December 31,2019,a total of 259 patients diagnosed with an AAA who underwent EVAR were recruited into this study.Based on the morphological characteristics of the proximal neck anatomy,the patients were divided into the HNA group and the friendly neck anatomy(FNA)group.The patients were followed up for up to 4 years.Results The average follow-up time was 1056.1±535.5 days.Type I endoleak occurred in 4 patients in the HNA group,and 2 patients in the FNA group.Neither death nor intraoperative switch to open repair occurred in either group.The time of the operation was significantly longer in the HNA group(FNA vs.HNA,99.2±51.1 min vs.117.5±63.8 min,P=0.011).There were no significant differences in short-term clinical success rate(P=0.228)or midterm clinical success rate(P=0.889)between the two groups.The overall mortality rate was 10.4%,and Kaplan-Meier survival analysis indicated that the two groups had similar cumulative survival rates at the end of the follow-up period(P=0.889).Conclusion EVAR was feasible and safe in patients with an AAA with a proximal HNA.The early and midterm results were promising;however,further studies are needed to verify the long-term effectiveness of EVAR.

Open surgical approach for two coincidental splenic artery aneurysms:a case report

Several factors can contribute to the formation of aneurysms,including hemodynamic changes,polyarteritis nodosa,bacterial endocarditis,vasculitis,fibromuscular dysplasia,vascular malformation,and cystic medial necrosis.^([1,2]) Surgery is recommended for splenic artery aneurysms (SAAs) greater than 25 mm in diameter,and several surgical approaches are used,including open surgery,laparoscopic surgery,and percutaneous embolization.Laparoscopic surgery might be associated with an increased risk of pancreatic leakage compared to the open surgery approach.

Mechanical compression management of the right middle cerebral artery inferior trunk using a stent during coil embolization of middle cerebral artery aneurysms:A case report and literature review

Endovascular coil embolization is a minimally invasive,rapid,and effective method for the treatment of intracranial aneurysms.However,complications associated with coil embolization,such as intraoperative aneurysm rupture or arterial occlusion,should be promptly managed during the procedure to avoid catastrophic consequences.This study presents a case of mechanical compression management of the right middle cerebral artery(MCA)inferior trunk during coil embolization for bilateral MCA aneurysms.The inferior trunk of the right MCA was abruptly occluded due to mechanical compression during coil embolization of the right MCA bifurcation aneurysm.A Solitaire AB stent(4×20 mm,Covidien/Medtronic,Dublin,Ireland)was implanted in the inferior trunk of the right MCA after tirofiban was injected via a microcatheter,and the right inferior trunk was recanalized.The patient also underwent coil embolization of the left MCA bifurcation aneurysm,without any complications.It is crucial to recognize compressive occlusion of adjacent aneurysm branches to avoid severe complications during intracranial aneurysm embolization.Stent placement is a rescue treatment option for recanalization of an occluded artery.

Stent-assisted coiling of intracranial carotid ophthalmic segment aneurysm segment aneurysms:Long-term follow-up from a single center

Background:To evaluate the efficacy of stent-assisted coiling(SAC)for the treatment of carotid ophthalmic segment aneurysm segment aneurysms(OSAs)of the internal carotid artery(ICA)through detailed long-term follow-up of a large patient cohort.Methods:We retrospectively analyzed 88 consecutive patients with OSAs between January 2009 and January 2020 at our center.Angiographic results were evaluated using the modified Raymond grading system and clinical outcomes were evaluated using the mRS scale.The primary endpoints were major aneurysm recurrence and poor clinical outcomes for at least 18 months of follow-up.The patients were asked to attend clinical follow-up assessments and possibly undergo DSA or MR via telephone.Results:We enrolled 88 patients with 99 OSAs treated with coiling,of whom 76 were treated with SAC.The coiling procedures were successful in all 88 patients.Overall,complications occurred in 8 patients(9.1%).No procedure-related mortality was observed.67(76.1%)experienced immediate aneurysm occlusion at the end of the procedure.Long-term angiographic follow-up(18 months)was available in 45/88 aneurysms(51%)(average 18.7±5.2 months).Four patients continued their follow-up for 5 years after initial aneurysm treatment.After a clinical follow-up time of 28.7 months(range,12-51 months),85 patients(95.5%)achieved favorable clinical outcomes(mRS scores of 0-2).Conclusions:This study indicates that SAC treatment is a safe and effective therapeutic alternative for ruptured and unruptured OSAs.The procedural risks are low with relatively long-term effectiveness.

Successive development of ischemic malignant strokes in a patient with multiple fusiform aneurysms:A case report

BACKGROUND Intracranial fusiform aneurysms are rare,spindle-shaped,and nonsaccular arterial dilatations that may be caused by dissection.CASE SUMMARY A 48-year-old man complained of wake-up onset of dysarthria and left-sided weakness.Diffusion-weighted magnetic resonance imaging of the brain revealed an infarction in the territories of the right middle and posterior cerebral arteries.Computed tomography angiography showed fusiform aneurysms in the right vertebral artery and bilateral petrous segments of the internal carotid arteries(ICAs).Despite conservative management,malignant ischemic stroke recurred in the contralateral ICA territory within a day of the onset of the index stroke.CONCLUSION We report a rare case of successive malignant strokes in a patient with multiple fusiform aneurysms.Herein,we emphasize that clinicians should consider aggressive treatment for patients with ischemic stroke and multiple fusiform aneurysms.

Nonclassical Cause of Obstructive Jaundice: A Case Report of Multiple Visceral Arterial Aneurysms in a Young Patient

Multiple visceral artery aneurysms are relatively rare;the rarest are superior mesenteric artery and gastroduodenal artery aneurysms. The clinical presentation depends on the size and site of the aneurysm. We report the case of a 33-year-old man with recurrent episodes of obstructive jaundice and weight loss. Computed tomography with contrast revealed scattered hepatic arterial aneurysms with two other aneurysms along the course of the left gastro-duodenal and superior mesenteric artery. Investigations to determine the etiology were negative, but the patient had a history of smoking and substance abuse. Angiography revealed an occluded feeding artery. The patient developed multiorgan failure, leading to cardiac arrest and died. Diagnosing multiple visceral artery aneurysms needs a high index of suspicion;early diagnosis enables early intervention, which can reduce the high mortality of this condition.

Hemodynamic investigations in intracranial aneurysms:a commentary

Intracranial aneurysms(IAs)are abnormal bulges in a blood vessel in the brain that have a potential to rupture and even causing a stroke,which can lead to lasting brain damage,long-term disability,or even loss of life.It has been widely acknowledged that hemodynamic factors,e.g.,instantaneous wall shear stress,time-averaged wall shear stress,wall shear stress gradient,gradient oscillatory number,oscillatory shear index,pulsatile blood flow waveform(flow rate magnitude and shape,physical flow period),relative residence time/turnover time,blood pressure.

Wall shear stress in intracranial aneurysms and adjacent arteries

Hemodynamic parameters play an important role in aneurysm formation and growth. However, it is difficult to directly observe a rapidly growing de novo aneurysm in a patient. To investigate possible associations between hemodynamic parameters and the formation and growth of intracranial aneurysms, the present study constructed a computational model of a case with an internal carotid artery aneurysm and an anterior communicating artery aneurysm, based on the CT angiography findings of a patient. To simulate the formation of the anterior communicating artery aneurysm and the growth of the internal carotid artery aneurysm, we then constructed a model that virtually removed the anterior communicating artery aneurysm, and a further two models that also progressively decreased the size of the internal carotid artery aneurysm. Computational simulations of the fluid dynamics of the four models were performed under pulsatile flow conditions, and wall shear stress was compared among the different models. In the three aneurysm growth models, increasing size of the aneurysm was associated with an increased area of low wall shear stress, a significant decrease in wall shear stress at the dome of the aneurysm, and a significant change in the wall shear stress of the parent artery. The wall shear stress of the anterior communicating artery remained low, and was significantly lower than the wall shear stress at the bifurcation of the internal carotid artery or the bifurcation of the middle cerebral artery. After formation of the anterior communicating artery aneurysm, the wall shear stress at the dome of the internal carotid artery aneurysm increased significantly, and the wall shear stress in the upstream arteries also changed significantly. These findings indicate that low wall shear stress may be associated with the initiation and growth of aneurysms, and that aneurysm formation and growth may influence hemodynamic parameters in the local and adjacent arteries.

Total splenic artery embolization for splenic artery aneurysms in patients with normal spleen

AIM: To evaluate total embolization of the main splenic artery in patients with splenic artery aneurysms (SAAs) and normal spleen.

Effectiveness of MRA on embolized intracranial aneurysms: a comparison of DSA, CE-MRA, and TOF-MRA

Purpose: The endovascular treatment of intracranial aneurysms was proven safe and effective compared to the alternative method of surgical clipping, despite the high recurrence rate. Follow-up of embolized intracranial aneurysms is mandatory for the early detection of recurrence and improved outcomes. DSA is used as the reference standard for this assessment. To determine the effectiveness of MRA in follow-up evaluations of intracranial aneurysms after embolization by comparing DSA, CE-MRA, and TOF-MRA. Materials and Methods: Sixty-eight consecutive patients undergoing DSA, TOF-MRA, and CE-MRA during an interval of <1 week were enrolled in this 6-month study. Images were evaluated for occlusion status, patency of the parent vessels, and artifacts. The modified Raymond-Roy occlusion classification and Aneurysm Embolization Grades were used to assess the occlusion status and initial DSA images for detection of recurrence in two filtered study phases with optimized selection criteria. Seventeen observers(phase I: 9, phase II: 8) independently interpreted the double-blinded images. Agreement was expressed with a Fleiss kappa value; p < 0.05 was considered significant. Results: This study included 68 patients with 77 aneurysms; 38(49.35%) were treated with coil alone and 39(50.65%) with stent-assisted coiling. In both phases, DSA was superior to TOF-MRA and CE-MRA using MRRC(Phase I: k = 0.567, p ≤ 0.001; k = 0.287, p ≤ 0.001; k = 0.117, p ≤ 0.001, respectively; Phase II: k = 0.503, p ≤ 0.001; k = 0.303, p ≤ 0.001; k = 0.115, p = 0.038, respectively). TOF-MRA was as effective as DSA(TOF: k = 0.335, p ≤ 0.001; DSA: k = 0.323, p ≤ 0.001) for recurrence detection. Conclusion: We suggest TOF-MRA as a first-line follow-up tool to detect aneurysm recurrence, and DSA to quantify the filling space to make a definite decision on re-embolization.

Evaluation of the safety and efficacy of a Pipeline Flex embolization device for treatment of large, wide-necked intracranial aneurysms

Objective: To investigate the safety and effectiveness of the Pipeline Flex embolization device(PFED) in the treatment of large and wide-necked aneurysms in the internal carotid artery(ICA). Methods: The clinical data of 78 cases of large and wide-necked aneurysms in the ICA treated with this Pipeline Flex embolization device in Shanghai Hospital of the Second Military Medical University and Southern Hospital of Southern Medical University from February 2017 to June 2018 were retrospectively analyzed. Results: A total of 66 cases were treated with a Pipeline Flex embolization device, 10 with a pipeline flex embolization device, and 2 with a double tubride stent(10 patients were treated with a pipeline stent-assisted coil embolization in; and 2 patients were treated with two pipeline stents). The patients were followed up for 3 to 18 months(average, 9.25 months). Among them, 63 cases had complete occlusion of the neck of the aneurysm(Raymondl Class I; MRS score 0; 80.8%). Aneurysms recurred in 12 cases(Raymondl Class Ⅱ; MRS score 1; 15.4%). Delayed ischemic complications were observed in 1 case(MRS score >2; 0.13%). There was 1 case of poor release of stent and 1 case of stent stenosis(0.13%). Conclusion: The treatment of large, wide-necked aneurysms in the ICA with PFED has a high total occlusion rate and good prognosis was better than coil embolization, but the placement of PFED still has some neurological complications.

Morphological characteristics associated with rupture risk of multiple intracranial aneurysms

Objective: To identify the morphological parameters that are related to intracranial aneurysms(IAs) rupture using a case-control model.Methods: A total of 107 patients with multiple IAs and aneurysmal subarachnoid hemorrhage between August 2011 and February 2017 were enrolled in this study.Characteristics of IAs location, shape, neck width, perpendicular height, depth, maximum size, flow angle, parent vessel diameter(PVD), aspect ratio(AR) and size ratio(SR) were evaluated using CT angiography.Multiple logistic regression analysis was used to identify the independent risk factors associated with IAs rupture.Receiver operating characteristic curve analysis was performed on the final model, and the optimal thresholds were obtained.Results: IAs located in the internal carotid artery(ICA) was associated with a negative risk of rupture, whereas AR, SR1(height/PVD) and SR2(depth/PVD) were associated with increased risk of rupture.When SR was calculated differently, the odds ratio values of these factors were also different.The receiver operating characteristic curve showed that AR, SR1 and SR2 had cut-off values of 1.01, 1.48 and 1.40, respectively.SR3(maximum size/PVD) was not associated with IAs rupture.Conclusions: IAs located in the ICA are associated with a negative risk of rupture, while high AR(>1.01), SR1(>1.48) or SR2(>1.40) are risk factors for multiple IAs rupture.

Kunming mouse strain is less susceptible to elastase-induced abdominal aortic aneurysms

Background:Porcine pancreatic elastase(PPE)is successfully used to induce abdominal aortic aneurysm(AAA)in mice.However,differences between mouse strains in susceptibility to PPE induction have been reported.Kunming mouse is one of the most frequently used strains in China but whether it is suitable for induction of AAA by PPE application remains unclear.Methods:PPE infusion(1.5 units/ml)in temporary controlled aorta was performed to induce AAAs in both C57BL/6J and Kunming mice.Phosphatebuffered saline(PBS)application was used as vehicle control.The aorta diameters of all mice were measured at days 0 and 14 after surgery to evaluate the AAA formation.Results:After 14 days of PPE or PBS infusion,all mice were sacrificed and aorta tissues were collected for histological staining analysis.At the 14th day after infusion,PPE successfully induced aortic dilation in Kunming mice and typical AAA in C57BL/6J mice.The aorta diameter increased by 0.23 mm in Kunming mice after PPE infusion,while it was 0.72 mm in the C57BL/6J strain.PPE induced mild elastin degradation,smooth muscle cell(SMC)depletion and mural leucocyte infiltration in Kunming mice,but in PPE-sensitive C57BL/6J mice,it induced total loss of SMCs,elastin disappearance and diffused infiltrated leucocytes in aortic aneurysmal segments.The effects of PPE in inducing angiogenesis and upregulating matrix metalloproteinase 2 and 9 expression in Kunming mice were also weaker than that in C57BL/6J mice.Conclusion:At the reported dose of PPE,Kunming mouse is not as susceptible to AAA formation as C57BL/6J mice.The failure of PPE to induce AAA formation in Kunming mice may be associated to its inability to boost a strong inflammatory response.

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.