Application of endovascular suture occlusion of middle cerebral artery in gerbils to obtain consistent infarction

Abstract

Middle cerebral artery occlusion (MCAO) by endovascular suture has gained increasing acceptance because it is relatively non-invasive and allows reperfusion. However, Its application in rats has resulted In inconsistent infarction volumes which involve only the subcortex or subcortex plus some cortex. In order to eliminate this drawback, we applied the intraluminal suture occlusion of MCA to gerbils that have an incomplete Circle of Willis. MCAO was induced by inserting an endovascular 5-0 nylon suture with a blunted tip into the Circle of Willis. Animals were divided into two groups: permanent MCAO for 24 h fn = 8) and transient MCAO for 3 h with 21 h reperfusion fn = 8). The corrected infarction volume in the permanent MCAO group was 232 ± 37 mm³ whereas it was 230 ± 45 mm³ in the transient MCAO group. All animals in both groups had infarction in both cortex and subcortex. Results of this study show that endovascular suture occlusion of MCA can be easily applied in gerbils to obtain consistent infarction. This would allow both transient and permanent focal ischemia to be tested in the same model of ischemia. [Neurol Res 1999; 21: 574–578]     

Comparison of silicon-coated nylon suture to plain nylon suture in the rat middle cerebral artery occlusion model

A variety of intraluminal sutures have been used in the middle cerebral artery occlusion model (MCAO) of focal ischemia. In the present study we tested commercially available silicon-coated nylon suture in the MCAO model and compared the results to traditional monofilament nylon suture occlusion. Twelve Sprague-Dawley male rats were randomly divided two groups, MCAO with 4-0 nylon suture (Group N, n=6) and MCAO with silicone-coated 4-0 nylon suture (Group S, n=6). Rats were sacrificed 24 h after reperfusion. Assessment included mortality rates, neurological evaluation, and infarct volume. One rat died in each group from subarachanoid hemorrhage. Neurological evaluation demonstrated that Group S tended to have worse neurological outcomes than Group N, although this difference was not statistically significant. On TTC stain Group S had significantly larger infarct volumes than Group N. We conclude that the commercially available silicone-coated occlusion suture provides better occlusion of the middle cerebral artery than the traditional uncoated nylon suture. Classification: Disease-related neuroscience (Section 6).     

Intraluminal spindle-shaped-head suture induced occlusion of middle cerebral artery in the rats

Objective: This study aimed to introduce a modified animal model of middle cerebral arterial occlusion (MCAO) through placement of intraluminal spindle-shaped head suture by comparing the traditional MCAO model.

Methods: A total of 60 male Spraque-Dawley (SD) rats were divided into two groups and MCAO was induced using spindle-shaped head suture or round head suture. The mortality, infarct volume, neurological function, success rate of the surgery, and stability of modeling were examined to evaluate the effectiveness of this model.

Results: Our results showed the success rate was 90.0% in spindle-shaped head group and 83.3% in round head group showing no significant difference; spindle-shaped head achieved a better establishment of MCAO model as shown in neurological examination. The infarct volume was 31.99 ± 5.44% in spindle-shaped head group and was significantly higher than in round head group (24.59 ± 7.17%; p < 0.05), and the coefficient of variation of infarct volume in spindle-shaped head group was lower than in round head group.

Conclusion: Our findings indicate that the modified suture induces a more reproducible and stable ischemic stroke following MCAO in SD rats.     

Internal borderzone infarction following acute middle cerebral artery occlusion

In 36 patients suffering acute middle cerebral artery (MCA) occlusion, we studied the angiographic findings within 6 hours of the ictus and the chronic CT results at 3 months. Seven patients suffering distal pial MCA branch occlusion developed a pattern of internal borderzone infarction on follow-up CT. Carotid artery or carotid siphon stenosis or occlusion was absent in all seven. Proximal MCA branch occlusions, prior to the origin of the lenticulostriate arteries, were associated with extensive cortical and deep infarction in the entire MCA territory in 14 patients. There was proximal carotid artery or siphon stenosis or occlusion in 12 of these 14 patients. The remaining 15 patients showed a mixture of proximal and distal MCA occlusions and patchy ischemic damage in the MCA territory. There were no cases of superficial cortical watershed infarction. These data show that internal borderzone infarctions may result from intracranial MCA branch occlusions alone and need not be associated with hemodynamic alterations due to large vessel extracranial disease.     

Proximal posterior cerebral artery occlusion simulating middle cerebral artery occlusion

We describe 12 cases of acute stroke in which clinical features of proximal posterior cerebral artery occlusion simulated the clinical syndrome of middle cerebral artery occlusion. The majority of patients developed contralateral hemiparesis, homonymous hemianopia, hemispatial neglect, and sensory loss or sensory inattention. All 8 patients with dominant hemisphere lesions were aphasic. Accurate diagnosis in each case was achieved only after a head CT, showing occipital lobe, thalamic, and inferomesial temporal lobe infarction. "Cortical" signs are probably explained by thalamic involvement. Recognition of this syndrome has implications for management and prognosis.     

Posterior cerebral artery infarction from middle cerebral artery infarction

BACKGROUND: While it is known that posterior cerebral artery (PCA) infarction may simulate middle cerebral artery (MCA) infarction, the frequency and localization of this occurrence are unknown. OBJECTIVE: To determine the frequency of PCA infarction mimicking MCA infarction and the territory of the PCA most commonly involved in this simulation. DESIGN: We studied 202 patients with isolated infarction in the PCA admitted to our stroke center to determine the frequency of PCA infarction simulating MCA infarction, the involved PCA territory, and the patterns of clinical presentation. RESULTS: We found 36 patients (17.8%) with PCA ischemic stroke who had clinical features suggesting MCA stroke. The PCA territory most commonly involved was the superficial PCA territory (66.7%), followed by the proximal PCA territory (16.7%) and both the proximal and the superficial PCA territories (16.7%). The principal stroke mechanism was cardioembolic (54.1%) in the superficial PCA territory, lacunar (46.2%) in the proximal PCA territory, and undetermined (40.2%) in both the proximal and the superficial territories. Among the 36 patients, the most common clinical associations were aphasia (13 patients), visuospatial neglect (13 patients), and severe hemiparesis (7 patients). CONCLUSIONS: Posterior cerebral artery infarction simulating MCA infarction is more common than previously thought. Early recognition of the different stroke subtypes in these 2 arteries may allow specific management.     

Reproducibility of cerebral cortical infarction in the wistar rat after middle cerebral artery occlusion

Although middle cerebral artery (MCA) occlusion in the rat is often used to study focal cerebral ischemia, the model of ischemia affects the size and reproducibility of infarction. The purpose of this experiment was to methodically examine different preparations to determine the optimum focal cerebral ischemia model to produce a reproducible severe ischemic injury. Eighty-two Wistar rats underwent either 1 hour, 3 hour, or permanent MCA occlusion combined with no, unilateral, or bilateral common carotid artery artery (CCA) occlusion. Three days after ischemia, the animals were prepared for tetrazolium chloride assessment of infarction size. One-hour MCA occlusion produced a coefficient of variation (CV) of 200% with an infarction volume of 20.3+/-10.5 mm(3). Adding unilateral or bilateral CCA occlusion resulted in a CV of 134% and 101%, respectively. Three-hour MCA occlusion combined with bilateral CCA occlusion decreased the CV to 58% with a cortical infarction volume of 82.6+/-12.1 mm(3), P<05, compared with 1-hour MCA occlusion with or without CCA occlusion. Permanent MCA occlusion combined with 3 hours of bilateral CCA occlusion resulted in a CV of 47% with a cortical infarction volume of 89.6+/-16.0 mm(3). These results indicate that 3-hour MCA occlusion combined with bilateral CCA occlusion provide consistently a large infarction volume after temporary focal cerebral ischemia.     

Prognosis in middle cerebral artery occlusion

The natural history of MCA occlusion has become increasingly important since the surgical option of EC/IC bypass surgery has been available. The clinical course of 24 patients with angiographically-demonstrated occlusion of the MCA artery was reviewed. Eight patients presented with a major disabling stroke and five of these died during the acute phase of this ischemic event. The remaining 19 patients were followed for a mean of 54.2 months. There were five deaths in follow-up and two of these were due to subsequent strokes. Fourteen patients manifested a benign course: one of these had a further minor stroke and four had TIAs. Altogether, 3 strokes occurred during the follow-up period (2 fatal, 1 minor) and all were in the territory of the artery known to be occluded. Of those patients who survived their presenting ischemic event, 12 (63%) remained completely functional in terms of activities of daily living. MCA occlusion does not necessarily carry a poor prognosis with medial therapy alone and the role of bypass surgery hopefully will be clarified by the ongoing clinically randomized trial.     

血管内再通术治疗症状性慢性大脑中动脉闭塞的初步临床观察

目的初步观察血管内再通术治疗症状性慢性大脑中动脉闭塞的临床疗效。方法纳入24例2019年1—12月郑州大学人民医院脑血管介入治疗中心采用血管内再通术治疗的症状性慢性大脑中动脉闭塞患者,回顾性观察血管再通的成功率、围手术期并发症的发生率及短期随访结果。结果24例患者中,20例(83.3%)血管成功再通,其中脑梗死溶栓治疗分级(TICI)2b级者6例,3级者14例;4例(16.7%)血管再通失败。共6例(25.0%)发生手术相关并发症。其中20例血管再通成功的患者中,发生蛛网膜下腔出血2例,高灌注脑出血1例,3例患者均行保守治疗,术后2周内出血均吸收,未遗留神经功能缺损症状;1例患者血管再通成功后突发心脏骤停死亡。4例血管再通失败的患者中,血管破裂1例,血管夹层1例。23例患者的术后随访时间为(5.0±1.3)个月(3~6个月)。20例血管再通成功的患者中,2例蛛网膜下腔出血者再通血管再次闭塞,末次随访时临床症状再发;其余患者无缺血症状再发,但影像学证实与术后即刻比较,1例血管狭窄率为42%,4例血管狭窄率≤10%。4例血管再通失败的患者脑缺血症状均再发。结论在严格掌握适应证的情况下,采用血管内再通术治疗症状性慢性大脑中动脉闭塞是可行的,相对安全;在短期内可改善患者的临床症状,但有再闭塞的风险;远期疗效需进一步观察。     

Provocative tests and parent artery occlusion in the endovascular treatment of distal middle cerebral artery pseudoaneurysms

We retrospectively analyzed the angiographic results and endovascular outcomes of 13 patients with pseudoaneurysms (PA) of the distal middle cerebral artery (dMCA). Endovascular provocative tests such as the temporary balloon occlusion test (BOT), and the super-selective intra-arterial "amytal" (amobarbital) test (IAT) were performed in these patients. Four patients underwent the BOT test and all patients underwent the IAT. The provocative tests were negative in 11 patients, after which successful parent artery occlusion (PAO) with detachable coils and onyx-18 was feasibly achieved. Immediate and 6-36 months of follow-up clinical evaluations showed a favorable outcome. Provocative tests are important in not only the selection of endovascular therapeutic methods for PA of the dMCA, but also to assist in accurately assessing patient prognosis.     

大鼠脑缺血再灌注后梗死体积的动态变化

目的观察大鼠大脑中动脉缺血再灌注后梗死灶体积的变化规律。方法线栓法制作大鼠局灶性脑缺血再灌注模型,观察脑缺血2h再灌注3h、24h、3d、7d、14d及21d后的神经功能缺损评分及2％氯化三苯基四氮唑(TTC)标记的梗死体积。结果缺血2h再灌注3h组已经出现较明显的梗死灶(梗死体积占前脑体积14．4％),再灌注24h组梗死体积最大(24．3％),显著大于再灌注3h、7d、14d、21d组(P<0．05)。再灌注3d组梗死灶仍较大 (23．8％),再灌注7d组梗死体积缩小(5．0％),再灌注14d组梗死灶进一步缩小(1．2％),再灌注21d组梗死灶基本消失(0．2％)。大鼠神经功能缺损评分与梗死体积之间呈显著相关(r=0．61,P<0．01)。结论脑缺血再灌注后梗死体积于24h达最大,21d时基本消失。脑缺血再灌注后神经功能缺损评分与梗死体积之间显著相关。     

超声助溶治疗急性大脑中动脉闭塞性脑梗死的临床研究

目的 探讨经颅多普勒超声联合rt-PA静脉溶栓治疗急性大脑中动脉闭塞性脑梗死的有效性及安全性,同时探索超声助溶的合适时间。方法 急性大脑中动脉闭塞性脑梗死患者73例,所有患者均行rt-PA静脉溶栓治疗,并按照超声助溶的时间随机分为3组,2 h超声助溶组24例、1.5 h超声助溶组25例和对照组24例。采用脑缺血溶栓血流分级判断血管再通情况,用美国国立卫生研究院卒中量表评分评估患者神经功能缺损程度,以溶栓后有无症状性颅内出血来评定其安全性,溶栓后3个月用改良Rankin量表及Barthel指数评分评定远期预后。结果 2 h助溶组与1.5 h助溶组治疗后2 h血管再通率以及治疗后3个月BI值显著高于对照组(P<0.05),而2助溶组之间血管再通率无明显差异(P>0.05); 2 h助溶组与1.5 h助溶组治疗24 h后NIHSS评分、治疗后3个月mRS评分显著低于对照组(P<0.05),而2助溶组之间无明显差异(P>0.05); 3组患者治疗后24 h均未出现症状性颅内出血。结论 超声助溶治疗急性大脑中动脉闭塞性脑梗死安全、有效、远期预后良好,而针对于助溶时间选择上建议将时间缩短至1.5 h。     

Thrombotic occlusion of the middle cerebral artery.

BACKGROUND AND PURPOSE: Epidemiological study of middle cerebral artery occlusion is important because the indication for extracranial-intracranial arterial bypass remains in dispute. To help clarify this issue, we investigated the prognosis of thrombotic middle cerebral artery occlusion in Japanese patients. METHODS: We studied 40 patients with thrombotic middle cerebral artery occlusion who were selected on the basis of clinical features, computed tomographic findings, and angiographic findings. Patients with causes of embolism (i.e., cardiomyopathy, valvular heart disease, cardiac arrhythmia, and carotid ulceration) were excluded. The 40 patients were classified into three groups according to the site of middle cerebral artery occlusion: there were 13 patients with occlusion of the proximal portion of the M1 segment, 13 with distal M1 segment occlusion, and 14 with occlusion of the M2 segment. RESULTS: Good collateral circulation was associated with improved outcomes both clinically and by computed tomography in patients with occlusion of the proximal and distal portions of the M1 segment but not in those with M2 occlusion. CONCLUSIONS: It is reasonable to assume that not only collateral circulation but also the site of occlusion plays an important role in the outcome of middle cerebral artery occlusion. Our finding that good collateral circulation improves the outcome for thrombotic occlusion of the proximal and distal M1 segments supports the possible benefits of such surgery.     

Neurological deficit and cerebral infarction after temporary middle cerebral artery occlusion in unanesthetized cats

Forty-four unanesthetized cats underwent temporary middle cerebral artery (MCA) occlusion with an implanted, externally controlled balloon cuff occluder. The occlusion was reversed to allow reperfusion of the MCA after 2 min to 24 hr of ischemia. Fourteen cats had temporary occlusions lasting 2 min to 3 hr; their neurological deficits improved or resolved after reperfusion, and brain sections showed only scattered microscopic areas of necrosis. After a 4-hr occlusion, five of nine cats (55%) recovered completely within 24 hr; two had persistent deficit when sacrificed, 10 days later, and each had a circumscribed infarct. All 18 cats undergoing 5-, 6-, 8-, and 24-hr occlusions sustained permanent neurological deficits. Three 3-hr occlusions at 2-day intervals in three cats resulted in permanent deficits and infarcts that were 25% larger than those after single 8-hr occlusions. Ten cats underwent permanent MCA occlusion; three deteriorated neurologically and died, and the survivors showed no improvement. Infarcts after 5-, 6-, and 8-hr occlusions followed by reperfusion were 66% smaller (p less than 0.05) than those after permanent occlusion; reperfusion after 24 hr of occlusion did not reduce infarct size. Hemorrhagic infarction occurred after two permanent occlusions, but after only one 5-hr temporary occlusion. The results obtained with this method of temporary regional ischemia indicate that restoration of flow after 1-8 hr, but not after 24 hr, of MCA occlusion resulted in less severe neurological deficit and smaller infarcts than did permanent occlusion. The infarct size correlated with the duration of MCA occlusion (p less than 0.05) rather than with the degree of deficit during occlusion.     

Distal hyperintense vessels alleviate insula infarction in proximal middle cerebral artery occlusion

Purpose: Insula involvement in acute cerebral ischemia more likely causes penumbral loss and poor clinical outcome than infarct-sparing insula. Our objective was to prove the hypothesis that abundant collateral circulation represented by distal hyperintense vessels (HV) on MRI alleviates insula infarction and facilitates prognosis. Material and Methods: One hundred and fourteen stroke cases with M1 totally occlusion on MR angiography were documented consecutively from 2012 to 2014. The degree of HV was graded as absent, subtle or prominent. Clinical data were recorded retrospectively by reviewing the medical records. The infarct volume on diffusion-weighted image, along with National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS), was used to evaluate the clinical severity and prognosis. Results: The degree of HV was more abundant in insula-uninvolved stroke compared with stroke involving insula infarction (p = 0.026). Insula-involved stroke patients were older (p = 0.039) with a higher percentage of atrial fibrillation history (p = 0.042). Univariate analysis revealed that insula infarction, age, infarct volume and NIHSS predicted unfavorable prognosis of stroke, whereas HV had a favorable effect. The protective effect of HV was confirmed by multivariate analysis. Conclusion: HV is a protective barrier between insula infarction and severity of clinical symptoms among stroke patients.     

Traumatic middle cerebral artery occlusion from boxing.

A case of a traumatic middle cerebral artery occlusion resulting from a boxing injury is presented. A 22-year-old man, an amateur boxer, was admitted because of difficulty in speaking, that had appeared a day after a sparring fight. A computed tomographic scan showed low-density areas in the left globus pallidus and corona radiata. A carotid angiogram indicated complete occlusion of the left middle cerebral artery at its origin and an irregularity and narrowing of the left internal carotid artery in its supraclinoid portion. The patient was discharged 4 weeks after the admission with some persistent expressive dysphasia that diminished during the next month. The clinical features and mechanisms of the traumatic middle cerebral artery occlusion are discussed.     

SEP监测在大脑前、中动脉动脉瘤栓塞术中的应用价值

目的探讨躯体感觉诱发电位(SEP)在颅内动脉瘤栓塞术中的应用价值。方法 2007年3月至2010年12月血管内栓塞治疗大脑中动脉(MCA)动脉瘤患者31例和大脑前动脉(ACA)动脉瘤患者25例,均行术中SEP监测,分析术中SEP的异常情况。结果共24例患者SEP发生异常(波幅下降>50%和潜伏期延长>10%),其中MCA动脉瘤栓塞时16例,ACA动脉瘤栓塞时8例。MCA动脉瘤栓塞时上肢SEP异常10例(32.3%),下肢SEP异常1例(3.2%),上下肢SEP均异常5例(16.1%)。ACA动脉瘤栓塞时,下肢SEP异常7例(28.0%),上下肢均异常1例(4.0%)。两组动脉瘤栓塞时上肢及下肢SEP异常率均差异明显(P<0.05)。MCAM1段动脉瘤栓塞术中SEP异常率最高,达37.5%(9/24)。SEP异常患者经术中干预后,21例SEP完全恢复正常,其中19例无新发神经功能障碍,1例下肢轻瘫,1例出现头晕;3例SEP部分恢复,术后出现相应的神经功能障碍。结论颅内动脉栓塞术中SEP监测有利于及时发现脑组织缺血(SEP异常)并及时给予术中干预,对降低患者脑梗死发生率及改善患者预后有重要意义。     

血管内尼龙线栓塞大鼠大脑中动脉局灶性脑缺血模型的改进

目的 确立更规范统一的制作大鼠局灶性脑缺血模型方法，使脑梗死体积更加稳定。方法 对24只大鼠使用液态硅胶涂层尼龙线栓塞大脑中动脉，分别缺血l，2，6和24h后再灌注24h，监测缺血侧局部脑血流，测定脑梗死体积及脑水肿程度。结果 缺血后所有大鼠局部脑血流均降到缺血前基值的25％以下，TTC染色显示所有动物在缺血侧皮质和尾状核均有明显的梗死灶和缺血，缺血1h组梗死体积与缺血2h以上组有显性差异，缺血2h以上各组之间梗死体积无显性差异；各组脑水肿程度无显性差异。结论 应用硅胶涂层尼龙线结合局部脑血流监测，缺血2h以上同时予以血流监测，可制作梗死体积稳定的大鼠局灶性脑缺血模型。