Extra-intracranial bypass surgery for vertebrobasilar insufficiency due to obstructive vertebral artery and vertebral-basilar artery junction disease

This report is on 19 patients with vertebrobasilar insufficiency in whom direct extra-intracranial arterial bypass surgery to the posterior circulation was performed. In all patients preoperative angiography had demonstrated vascular lesions of haemodynamic significance of either one or both vertebral arteries (VA) or within the vertebral-basilar artery junction (VABAJ). The bypass procedure was performed between the occipital artery (OA) and - depending on the localization of the obstructive vascular lesion - the posterior inferior cerebellar artery (PICA), the VA or the anterior inferior cerebellar artery (AICA). A modification of the operative technique is presented with using a paramedian approach. The clinical results of this series support the concept that a patent extra-intracranial graft to the posterior circulation may have a protective effect by preventing further ischaemic events.     

椎动脉优势与后循环缺血性眩晕的关系

目的 探讨椎动脉优势在后循环缺血性眩晕(VAIV)中的临床意义.方法 前瞻性收集经头颅MRA检查发现的椎动脉优势的VAIV患者41例为研究对象,以非椎动脉优势的患者36例为对照,比较两组患者的基底动脉情况及眩晕严重程度.将椎动脉优势组患者根据椎动脉直径差异分为轻度变异组(0.04～0.70mm)、中度变异组(0.70～1.17 mm)、重度变异组(≥1.17 mm)3组,比较3组患者的眩晕严重程度差异.所有患者均随访1年,观察椎动脉优势与阳性事件发生(眩晕反复发作或发生后循环脑梗死)的关系.结果 (1)椎动脉优势组基底动脉形状异常率为70.73％(29/41),明显高于非椎动脉优势组33.33％(12/36)(x2=10.77,P＜0.01);(2)椎动脉优势组眩晕严重程度(3.3±1.2)高于非椎动脉优势组(2.3±0.6)(t=1.99,P＜0.01);不同变异3组间两两比较,椎动脉优势重度变异组眩晕严重程度(4.0±1.1)大于轻度变异组(2.9±0.9)(t=2.07,P＜0.05);(3)随访1年后,椎动脉优势组阳性事件发生率(65.85％)高于非优势组(30.56％)(x2=9.56,P＜0.01).结论 椎动脉优势的VAIV患者基底动脉异常率高,眩晕程度更严重,更容易反复发作眩晕或发生后循环脑梗死.     

Rotational vertebrobasilar insufficiency due to dynamic compression of the dominant vertebral artery by the thyroid cartilage and occlusion of the contralateral vertebral artery at C1-2 level.

BACKGROUND: Vertebrobasilar insufficiency caused by head rotation is an uncommon event. The mechanism is obstruction of the vertebral artery resulting in flow limitation or, less frequently, thromboembolism. CASE DESCRIPTION: A 41-year-old male developed dizziness and light-headedness during chiropractic manipulation when his head was turned to the extreme right position. Computed tomography angiography (CTA) of the neck and selective digital subtraction angiography (DSA) of the vertebral arteries revealed that when the patient turned his head to the extreme right position the dominant right vertebral artery was compressed between the posterior aspect of the thyroid cartilage and anterior aspect of the right transverse process of C6 resulting in focal stenosis, while the left vertebral artery is severely compressed with significant flow limitation at the level of C1-2. Because the patient was healthy and asymptomatic, conservative management was adopted. At the 9-month follow-up visit the patient was asymptomatic and able to compensate for his problem avoiding turning his head to the extreme right position. CONCLUSIONS: We present an uncommon case of rotational vertebrobasilar insufficiency (VBI) where the dominant vertebral artery has an anomalous course compressed by the thyroid cartilage at C6 level, associated with contralateral vertebral artery rotational stenosis at C1-2. The patient was successfully managed conservatively.     

椎-基底动脉重度狭窄的血管内治疗

目的回顾性分析椎-基底动脉重度狭窄患者临床诊断与治疗经过,以评价血管内支架成形术的可行性和临床疗效。方法16例椎-基底动脉重度狭窄患者均施行血管内支架成形术,观察其技术成功率、围手术期并发症发生率及远期疗效。结果16例患者经脑血管造影检查共发现27个狭窄病变,共成功植入36枚球囊扩张式支架,技术成功率达100%(16/16)。1例于手术后24h发生支架内急性血栓形成,围手术期并发症发生率为6.25%(1/16)。随访期间,3例(18.75%)发生支架内再狭窄而致卒中再发。结论血管内支架成形术治疗椎-基底动脉重度狭窄,在技术上可行,远期疗效良好。     

Stroke due to vertebral artery injury

Minimal neck injury produced vertebral artery damage in two women and three men, 20 to 57 years of age. Serious neurologic deterioration occurred in two patients when positioned for roentgenographic procedures. Dissection or thrombosis of one or both vertebral arteries while in the transverse foramina occurred in three, one at the site of an osteophyte. The arteriogram of one patient showed a traumatic aneurysm at C-7, and a second patient had segmental arterial stenosis with bilateral traumatic aneurysms at C-5. The location of the arterial injury is not restricted to the occipitoatlantoaxial level but includes the course through the transverse foramina. The use of anticoagulation appears to be important in the immediate management of this process.     

The sympathetic nervous system in hypertension due to unilateral renal artery stenosis in man

The contribution of neurogenic mechanisms in maintaining hypertension was investigated in 13 patients with unilateral renal artery stenosis (twelve with normal, one with grossly elevated plasma renin levels) by determining the haemodynamic and hormonal responses to the centrally acting sympatholytic agent, clonidine. The same patients were studied after captopril to determine the dependency of their blood pressure on the direct peripheral effects of angiotensin-II. Sixteen patients with essential hypertension (normal plasma renin) were additionally studied after clonidine. After clonidine, blood pressure fell markedly in patients with renal artery stenosis (17 ± 3%) and essential hypertension (18 ± 2%). In both groups, clonidine lowered cardiac output by a reduction in stroke volume and heart rate; forearm vascular resistance was unchanged but digital skin vascular resistance fell. Plasma noradrenaline levels were normal in both groups and fell after clonidine; plasma renin activity and aldosterone levels were unchanged. After captopril, blood pressure fell minimally (5 ± 3%) in renal artery stenosis patients; cardiac output fell and forearm and digital skin vascular resistance were unchanged. Plasma renin activity rose, plasma aldosterone fell and plasma noradrenaline was unchanged after captopril. In the patient with grossly elevated renin levels, blood pressure fell minimally (6%) after clonidine, but unlike others fell profoundly (37%) after captopril. We conclude that, in the majority of our renal artery stenosis patients, despite the elevated blood pressure, sympathetic nervous activity was not reduced. Central neurogenic mechanisms appear to play an important role in maintaining raised blood pressure. In the same patients the peripheral effects of angiotensin-II did not maintain vascular tone or hypertension. The ischaemic kidney has a key role however, as revascularization or nephrectomy cured or ameliorated the hypertension.     

Left hemibody myoclonus due to anomalous right vertebral artery.

A 43-year-old man presented with sporadic, sudden, brief, and involuntary jerks of his left limbs and trunk muscles. The electromyographic recordings showed short-lasting highly synchronized bursts, compatible with myoclonus limited to the left hemibody. Blink reflex, masseter silent period, cortical and spinal magnetic stimulation, somatosensory cortical evoked potentials, and electroencephalogram (EEG) were normal; the EEG back-averaging showed no spikes preceding the myoclonus. Magnetic resonance imaging and magnetic resonance angiography showed the presence of an anomalous nonectasic right vertebral artery compressing the right side of ventral medulla oblongata. We hypothesize that the aberrant right vertebral artery induced abnormal activation of descending motor tracts responsible for the myoclonus.     

支架成形术治疗椎动脉颅内段和基底动脉狭窄17例临床观察

目的评估症状性椎动脉颅内段、基底动脉狭窄患者经皮血管内支架成形术(PTAS)治疗的安全性和有效性。方法17例症状性椎动脉颅内段及基底动脉狭窄患者,狭窄程度在50%以上且规范的内科药物治疗无效,给予PTAS治疗,术后常规给予抗凝、抗血小板聚集、降脂药物。结果17例患者20处狭窄行PTAS,所有的病例手术均取得成功,没有严重并发症,术后即刻造影残存狭窄平均在10%以下,病人平均随访6.8个月(3～10个月),有1例患者出现再狭窄(狭窄程度>50%),所有患者均无缺血症状发作。结论PTAS治疗椎动脉颅内段及基底动脉狭窄是安全和有效的。     

12例椎-基底动脉串联病变的血管内治疗探讨

目的探讨经皮血管内支架成形术(PTAS)治疗椎-基底动脉重度狭窄串联病变的有效性、安全性及可行性。方法对12例(26处)经药物治疗无效的症状性椎-基底动脉串联病变患者采用经皮血管内支架成形术治疗。术前DSA示动脉直径狭窄率为65～100%,平均84.62±8.24%。结果本组支架置放成功率92.6%,术后平均狭窄率为16.92±14.84%;术后用mRS量表(改良RANKIN量表)评分,7例0分,3例1分,2例3分。发生2例围手术期并发症,年卒中率为6.2%;随访期间2例发生支架内再狭窄。结论血管内支架成形术治疗椎-基底动脉串联病变,在技术上可行,远期疗效良好。     

Rotational vertebral artery syndrome due to compression of nondominant vertebral artery terminating in posterior inferior cerebellar artery

Rotational vertebral artery syndrome (RVAS) is characterized by recurrent attacks of paroxysmal vertigo, nystagmus, and ataxia induced by head rotation. We report on a patient who developed atypical RVAS due to compression of the vertebral artery (VA) terminating in the posterior inferior cerebellar artery (PICA). A 59-year-old man suffered from vertigo and nystagmus induced by leftward head rotation and oculography showed right beating horizontal-torsional and downbeat nystagmus. Cerebral angiography showed hypoplastic right VA terminating in PICA without connection to the basilar artery. The basilar artery received its flow from the left VA only and branched out both anterior inferior cerebellar arteries. Cerebral angiography revealed a complete occlusion of the right distal VA at the level of the C1–2 junction when the head was rotated to a leftward position. In contrast, the blood flow through the left vertebral and basilar arteries remained intact while turning the head to either side. The hemodynamic compromise observed in our patient with RVAS indicates that isolated vertigo and nystagmus may occur due to transient ischemia of the inferior cerebellum or lateral medulla.     

Pure motor stroke due to vertebral artery dissection

A 39-year-old man presented with a pure motor stroke 9 days after cervical chiropractic manipulation. Computerised tomographic scanning showed a pontine infarct. Cerebral angiography showed changes consistent with the diagnosis of bilateral vertebral artery dissection. It is postulated that the infarct resulted from artery-to-artery embolism.     

后循环梗死与椎基底动脉狭窄的相关性分析

目的 探讨MRI所示的后循环梗死灶与DSA发现的椎基底动脉狭窄的相关性.方法 回顾分析30例后循环梗死患者的临床资料,将每例后循环梗死患者头部MRI发现的梗死灶与DSA所见的椎基底动脉狭窄血管进行对照.结果 MRI示单发性梗死22例(其中脑干梗死10例,小脑梗死8例,丘脑梗死2例,枕叶梗死2例),多发性梗死8例.DSA...