Clinical presentation and management of giant anterior communicating artery region aneurysms.

OBJECT: The authors reviewed their 20-year experience with giant anterior communicating artery aneurysms to correlate aneurysm size with clinical presentation and to analyze treatment methods. METHODS: In 18 patients, visual and cognitive impairment were quantitated and clinical outcome was categorized according to the Rankin scale. Statistical analysis was performed using Fisher's exact test. CONCLUSIONS: At least 3.5 cm of aneurysm mass effect was required to produce dementia in the patient (p = 0.0004). Dementia was usually caused by direct brain compression by the aneurysm rather than by hydrocephalus. Optic apparatus compression occurred with smaller aneurysms (2.7-3.2 cm) when they pointed inferiorly. Aneurysm neck clipping was possible in half of the cases. Special techniques, including temporary clipping, evacuation of intraluminal thrombus, tandem and/or fenestrated clipping, and clip reconstruction were often required. Occlusion of or injury to the anterior cerebral artery (ACA) was the main cause of poor outcome or death. Proximal ACA occlusion, even of dominant A1 segments with small or no contralateral A1 artery, was an effective treatment alternative and was well tolerated as a result of excellent leptomeningeal collateral circulation.

[Current management of carotid artery stenosis. What does the evidence show us?]. / Manejo actual de la estenosis carotídea. Qué es lo que la evidencia nos demuestra?

OBJECTIVE: Surgery of carotid artery stenosis as treatment for acute cerebral vascular accident was most used in the 1980s. This surgical procedure is one of the few to have been 'examined' to demonstrate its usefulness by means of a series of prospective multicentric trials, carried out between 1980 and 1990. This paper aims to show the results of these trials and give useful advice for current management of these patients. DEVELOPMENT: We describe the most important studies carried out to date, both in the group of patients with symptomatic and those with asymptomatic carotid artery stenosis. We emphasize the importance of achieving low morbi-mortality, both in the surgical procedure and in diagnosis. We describe the advantages and disadvantages of non-invasive methods of diagnosis, alternatives to cerebral angiography, and discuss current indications for carotid artery surgery in symptomatic and asymptomatic groups. CONCLUSIONS: The most important cooperative studies (ECST and NASCET) have shown the validity of surgical in combination with medical treatment, as opposed to medical treatment alone, in order to avoid further neurological incidents in patients with symptomatic carotid stenosis. The only cooperative study which has shown the superiority of surgical treatment, as compared with medical treatment, in a group of asymptomatic patients was ACAS (particularly in male patients).

Risk factors of moyamoya disease in Canada and the USA.

Over the past 28 years, 39 patients with Moyamoya disease or syndrome defined as spontaneous occlusion of the circle of Willis with extensive basal collateral vessels have been treated by the author in Canada and the USA. All patients presented with clinical or radiologic evidence of hemorrhage (23) or ischemia and infarction (16). A total of 12 patients had associated cerebral aneurysms and seven of these patients with aneurysms presented with subarachnoid hemorrhage. The patients ages ranged from 5 to 47 years. Of these 58% were female. The patients racial origin included North American Indian, Innuit, East Indian/Pakistani, Japanese, Chinese, Filipino, Korean, Malayasian, Hispanic, African American and Caucasian. Familial clustering was seen in North American Indian, Innuit and Caucasian patients. Associated disorders (tuberculosis, pharyngitis, thalassemia, fibromuscular hyperplasia, polycystic kidney, sickle cell trait and hypertension) were common in these patients, as was the use of tobacco, alcohol and in the adult females, oral contraceptives. It may be concluded from this series that the etiology of Moyamoya disease or syndrome is probably multifactorial, but that some racial and familial groups are more susceptible. Furthermore, in that the clinical and angiographic features are identical, the separation between Moyamoya disease and syndrome may not be helpful in understanding the etiology and pathophysiology of this disorder.

Giant fusiform intracranial aneurysms: review of 120 patients treated surgically from 1965 to 1992.

The paucity of information about giant fusiform intracranial aneurysms prompted this review of 120 surgically treated patients. Twenty-five aneurysms were located in the anterior and 95 in the posterior circulation. Six patients suffered from atherosclerosis and only three others had a known arteriopathy. The remaining 111 patients presented with aneurysms resulting from an unknown arterial disorder; these patients were much younger than those harboring atherosclerotic aneurysms. Mass effect occurred in only 50% of cases and hemorrhage in 20%. Eight aneurysms caused transient ischemic attacks. Hunterian proximal occlusion or trapping were dominant among the treatment methods. In contrast to the management of giant saccular aneurysms, the usual thrombotic occlusion of a giant fusiform aneurysm after proximal parent artery occlusion requires the presence of two collateral circulations to prevent infarction, one for the end vessels and another for the perforating vessels that arise from the aneurysm. Although there was some reliance on the circle of Willis and on collateral vessels manufactured at surgery, the extent of natural leptomeningeal and perforating collateral, thalamic, lenticulostriate, and brainstem vessels was astonishing and formerly unknown to the authors. Good outcome occurred in 76% of patients with aneurysms in the anterior circulation; two of the six cases with poor results included patients who were already hemiplegic. Ninety percent of patients with posterior cerebral aneurysms fared well. Only 67% of patients with basilar or vertebral aneurysms had good outcomes, although more (17%) of these patients were in poor condition preoperatively because of brainstem compression.

Pseudotumor syndrome resulting from a cerebral arteriovenous malformation: case report.

We report a case of a cerebral arteriovenous malformation presenting as a pseudotumor cerebri syndrome. The lack of mass effect, hemorrhage, or hydrocephalus, in addition to angiographic evidence of high-flow and venous outflow restriction, implicate increased cerebral blood flow and venous hypertension as the mechanism for the papilledema. This case illustrates a pathophysiological mechanism in the development of intracranial hypertension associated with vascular malformations.

Hunterian proximal arterial occlusion for giant aneurysms of the carotid circulation.

Hunterian proximal artery occlusion was used in the treatment of 160 of 335 patients harboring giant aneurysms of the anterior circulation. One hundred and thirty-three of these aneurysms arose from the internal carotid arteries, 20 from the middle cerebral arteries, and seven from the anterior cerebral arteries. Ninety percent of the patients had satisfactory outcomes. The safety of internal carotid artery occlusion has been greatly enhanced by preoperative flow studies and by test occlusion with an intracarotid balloon to identify those patients who require preliminary extracranial-to-intracranial bypass, which was used in all of the middle cerebral occlusions. The anterior cerebral artery had magnificent leptomeningeal collateral flow that prevented infarction even without cross flow. Obliteration of the aneurysm by thrombosis was complete, or nearly so, in all but four patients whose treatment was completed. Analysis of poor outcome in 16 patients revealed that hemodynamic ischemic infarction was known to occur after only two of the carotid occlusions.

Early surgery for ruptured vertebrobasilar aneurysms.

The authors present a series of 1767 patients with aneurysms of the vertebrobasilar circulation, most of whom were operated on 14 days or more following their last subarachnoid hemorrhage (SAH). Since 1970, 206 patients with vertebrobasilar aneurysms have been surgically treated within 7 days after their last SAH (day of SAH = Day 0). Of patients with a good preoperative grade (Botterell Grade 1 or 2), a good or excellent outcome was obtained in 80% during the first postsurgical month, irrespective of the timing of surgery. All except one of the Grade 5 patients died, and 70% of the Grade 4 patients were significantly disabled or dead. The overall operative mortality rate was the same whether surgery took place in the 1st week after SAH or was delayed. The frequency of rupture of the aneurysm during early surgery was not higher than during late surgery. Thirteen percent of patients developed a delayed ischemic neurological deficit as a consequence of reactive arterial narrowing (vasospasm). The authors recommend early surgery for patients with a good preoperative grade, whose aneurysm does not present a particular technical difficulty because of size, configuration, or location, and occasionally in patients whose lives appear to be in jeopardy because of recurrent hemorrhage.

Deliberate basilar or vertebral artery occlusion in the treatment of intracranial aneurysms. Immediate results and long-term outcome in 201 patients.

Deliberate occlusion of the basilar or vertebral arteries was performed in 201 patients with intracranial aneurysms, where the aneurysmal neck could not be clipped directly. The aneurysms arose from the basilar apex in 83 cases, the basilar trunk in 46, the vertebrobasilar junction in 35, and the vertebral artery in 37; 87% of the aneurysms were classified as giant lesions (> 2.5 cm). There were 85 upper basilar occlusions, 41 lower basilar occlusions, 29 bilateral vertebral occlusions, and 48 unilateral vertebral artery occlusions. The clinical follow-up period varied from 1 to 23 years, with a mean of 9.5 years. Overall long-term results were excellent in 68% of the patients, good in 5%, and poor in 3%; 24% died. Clinical outcome varied according to aneurysm site; excellent or good results were achieved in 64% of the patients with basilar apex, 76% with basilar trunk, 74% with vertebrobasilar junction, and 87% with vertebral artery aneurysms. Clinical outcome also varied depending on preoperative grade: 86% of the patients with an excellent presenting grade achieved excellent results. The size of the posterior communicating arteries was a good predictor of tolerance to basilar artery occlusion (p < 0.05). Successful aneurysm thrombosis was achieved in 78% of the patients. The neurological status in 26 patients (13%) deteriorated due to vertebrobasilar ischemia occurring within the 1st postoperative week, and thrombosis or embolism was implicated much more frequently than hemodynamic insufficiency. Subarachnoid hemorrhage (SAH) in 14 patients, vasospasm in five patients, and surgical trauma in seven patients accounted for additional morbidity in the 1st month following operation; however, many of these patients ultimately made an excellent recovery. Late vertebrobasilar ischemic complications or neurological deterioration from persistent mass effect occurred in 4% of patients with successful aneurysm thrombosis 6 weeks to 18 months after arterial ligation. Among the 43 patients with incompletely thrombosed aneurysms, 67% developed early or late neurological deterioration from SAH, progressive brain-stem compression, or brain-stem stroke, with 86% of the complications proving fatal.

Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis.

BACKGROUND: Without strong evidence of benefit, the use of carotid endarterectomy for prophylaxis against stroke rose dramatically until the mid-1980s, then declined. Our investigation sought to determine whether carotid endarterectomy reduces the risk of stroke among patients with a recent adverse cerebrovascular event and ipsilateral carotid stenosis. METHODS: We conducted a randomized trial at 50 clinical centers throughout the United States and Canada, in patients in two predetermined strata based on the severity of carotid stenosis--30 to 69 percent and 70 to 99 percent. We report here the results in the 659 patients in the latter stratum, who had had a hemispheric or retinal transient ischemic attack or a nondisabling stroke within the 120 days before entry and had stenosis of 70 to 99 percent in the symptomatic carotid artery. All patients received optimal medical care, including antiplatelet therapy. Those assigned to surgical treatment underwent carotid endarterectomy performed by neurosurgeons or vascular surgeons. All patients were examined by neurologists 1, 3, 6, 9, and 12 months after entry and then every 4 months. End points were assessed by blinded, independent case review. No patient was lost to follow-up. RESULTS: Life-table estimates of the cumulative risk of any ipsilateral stroke at two years were 26 percent in the 331 medical patients and 9 percent in the 328 surgical patients--an absolute risk reduction (+/- SE) 17 +/- 3.5 percent (P less than 0.001). For a major or fatal ipsilateral stroke, the corresponding estimates were 13.1 percent and 2.5 percent--an absolute risk reduction of 10.6 +/- 2.6 percent (P less than 0.001). Carotid endarterectomy was still found to be beneficial when all strokes and deaths were included in the analysis (P less than 0.001). CONCLUSIONS: Carotid endarterectomy is highly beneficial to patients with recent hemispheric and retinal transient ischemic attacks or nondisabling strokes and ipsilateral high-grade stenosis (70 to 99 percent) of the internal carotid artery.

Magnetic resonance imaging of facial nerve neuromas.

Facial nerve neuromas are uncommon tumors often confused with other tumors of the temporal bone and cerebellopontine angle. Radiologically, it may be impossible to differentiate an intracanalicular facial nerve neuroma from an acoustic neuroma. We present three case reports of facial nerve neuromas arising within the internal auditory canal to show the important magnetic resonance imaging features of these tumors. One tumor extended into the cerebellopontine angle, middle cranial fossa, and middle ear. Another filled the internal auditory canal and extended through the cerebellopontine angle to the brain stem. The third occurred in a patient who had neurofibromatosis as well as numerous other intracranial tumors. We feel that gadolinium-enhanced magnetic resonance imaging provides the most useful information in the preoperative assessment of this disorder.

Surgical treatment of unruptured aneurysms of the posterior circulation.

With the ever-increasing number of intact aneurysms revealed by modern imaging, the options for their management are assuming great importance. While some knowledge has emerged as to their natural history and the results of surgical treatment of those in the anterior circulation, little information has been published concerning unruptured aneurysms arising from the posterior circulation. The authors report their experience since 1971 with 167 patients operated on for 179 unruptured vertebrobasilar aneurysms up to 25 mm in diameter. Overall, 160 aneurysms were treated by direct clip obliteration, while 19 were managed by alternative methods. Fifty-three patients (32%) had solitary aneurysms and the other 114 patients (68%) had multiple aneurysms or an associated arteriovenous malformation, which were commonly treated concurrently. Many of these coexisting vascular anomalies had ruptured in the recent or remote past, adding to the complexity of management and interpretation of specific surgical results related to the intact posterior circulation aneurysm. There were 78 documented postoperative complications including 23 systemic complications, seven postoperative hematomas, six brain injuries from retraction, five cases of aseptic meningitis, three instances of seizures, three wound infections, and three patients with hydrocephalus. Multiple complications occurred in 23 patients. Seventy-one of the patients with these untoward events recovered, without disability, with time or treatment. There were only six poor results and one death in the series, resulting in a 4.2% combined morbidity/mortality rate. However, since two of these poor outcomes and the single death were attributable to a coexisting aneurysm, the actual surgical morbidity related specifically to the posterior circulation aneurysm was only 2.4%. This experience suggests that non-giant, intact vertebrobasilar aneurysms can be obliterated surgically at a very low risk, and this treatment should eliminate the greater lifetime risk related to an unsecured aneurysm.

Rupture of aneurysms following balloon embolization.

Three cases of complex aneurysms are presented in which balloon embolization therapy was associated with subsequent aneurysmal rupture, causing subarachnoid hemorrhage in two cases and a carotid-cavernous fistula in one. Two of these patients were treated directly by balloon embolization following surgical exploration. The third patient developed the fistula during postembolization volume expansion and heparinization.

Carotid transluminal angioplasty with evidence of distal embolization. Case report.

A 57-year-old woman presented with symptomatic triple tandem stenosis of the left carotid artery. Transluminal angioplasty of an atherosclerotic stenosis at the origin of the common carotid artery was performed retrogradely through a distal arteriotomy after endarterectomy. The postangioplasty effluent was collected and analyzed. Cholesterol crystals and amorphous plaque debris were identified, indicating a source for distal embolization. The clinical significance of this small amount of debris embolizing to the intracranial circulation is uncertain, but should be of concern when considering angioplasty of the cerebral circulation.

The effects of a prophylactic bolus of lidocaine in focal cerebral ischaemia.

In order to determine the cerebral protective effects of an intravenous bolus of 5 mg.kg-1 of lidocaine, the left middle cerebral artery (MCA) was transorbitally occluded in 19 cats. Ten animals received the lidocaine bolus and nine a similar volume of saline immediately before MCA occlusion. Somatosensory evoked potentials (SEP) were recorded before and after the lidocaine bolus as well as continually after MCA occlusion. After six hours of vessel occlusion and without reperfusion, the animals were sacrificed and the brains fixed for histology. Prior to MCA occlusion, lidocaine caused a statistically significant (p less than 0.01) reduction in the amplitude of the major cortical component of the SEP (10 +/- 1.2 microV vs 6.0 +/- 1.3 microV). Latency was unchanged. In the lidocaine group, SEP's persisted in 40 per cent immediately following occlusion whereas they disappeared in all of the control animals (p less than 0.05). Gradual recovery occurred in both groups and there were no differences at the end of the experiment although the amplitudes tended to be greater in the lidocaine group. There were no statistically significant differences in the histological size or severity of the infarcts between the groups. Although infarct size was not reduced, transient sparing of the SEP suggests that further studies of lidocaine by continuous infusion in models of temporary focal cerebral ischaemia may be warranted.

Platelet aggregation within cerebral arteriovenous malformations.

Turbulence within cerebral arteriovenous malformations (AVM's) may lead to endothelial disruption, platelet aggregation, and thrombus formation. This hypothesis would account for many of the pathological features in AVM's, including intimal hyperplasia and arterial thrombosis with or without organization. In this study, a dual-isotope method employing indium-111-labeled platelets and technetium-99m-labeled red blood cells was used to evaluate in vivo platelet aggregation in 20 patients with AVM's. The use of two isotopes allows subtraction of the blood-pool platelets and calculation of the ratio of the indium deposited:the indium in the blood pool (In(D)/In(BP)). After a 24-hour incubation period, eight of the 20 patients demonstrated platelet aggregation in their AVM's with a mean In(D)/In(BP) ration of 0.71 +/- 0.36 (+/- standard deviation). Seven of these AVM's were available for pathological study and all of them demonstrated evidence of arterial thrombosis of variable age. In the remaining 12 patients, the In(D)/In(BP) ratio was not significantly elevated (mean 0.02 +/- 0.13), indicating the absence of active platelet aggregation during this short interval of study. Five of these AVM's were pathologically examined, four of which showed evidence of arterial occlusion. It is concluded that platelet aggregation is a common occurrence in cerebral AVM's and may account for the dynamic histopathology often seen in these lesions.

Functional status changes following medical or surgical treatment for cerebral ischemia. Results of the extracranial-intracranial bypass study.

To determine the value of extracranial-intracranial arterial anastomosis (EC/IC bypass), we randomly allocated 1377 patients with symptomatic atherosclerosis of the internal carotid or middle cerebral arteries to medical care alone or to EC/IC bypass with continuing medical care. As previously reported, surgery did not reduce--or significantly increase--the risk of stroke. Functional status data collected during the trial provide new information. Six weeks following entry, surgical patients showed greater dysfunction in the following activities: fluency of speech, getting in and out of bed, sitting down and standing up, toileting, cutting food and pouring beverages, and dressing and undressing. At 4.5 months, surgical patients still exhibited greater dysfunction in toileting, with nonsignificant trends in several other activities. From six months onward, there were no significant differences between the groups. Thus, EC/IC bypass results in transient worsening of functional status beyond the immediate perioperative period.

Saccular aneurysms in basilar artery fenestration.

Of 59 cases of vertebrobasilar junction aneurysms diagnosed and treated from January 1977 to April 1986, 21 (35.5%) saccular aneurysms arose in a fenestration of the proximal basilar artery. Defects of the media at the junctures of the fenestrated segments, as well as the possible presence of turbulent flow at the vertebrobasilar junction, may explain the high incidence of vertebrobasilar aneurysms associated with proximal basilar artery fenestration.

Lumbar puncture and stroke. A statement for physicians by a Committee of the Stroke Council, American Heart Association.

This statement for physicians redefines the use and importance of lumbar puncture to suspected stroke mechanisms. It also identifies neurologic conditions in which newer imaging techniques are safer and more effective diagnostic tools than lumbar puncture.

Use of detachable balloons for proximal artery occlusion in the treatment of unclippable cerebral aneurysms.

Of 68 patients with unclippable aneurysms treated by proximal artery occlusion with detachable balloons, permanent occlusion was achieved in 65; of these patients, 37 had carotid artery aneurysms below the origin of the ophthalmic artery, 21 had aneurysms arising from the supraclinoid portion of the carotid artery, six had basilar trunk aneurysms, and one had a distal vertebral aneurysm. Examination for treatment selection included assessment of the circle of Willis by compression angiography and xenon blood flow studies, with the ultimate evaluation being test occlusion under systemic heparinization with the balloon temporarily placed in the desired position. Of 67 patients who underwent a formal occlusion test, eight with carotid artery aneurysms did not initially tolerate the occlusion test, and ischemic signs disappeared instantaneously with deflation and removal of the balloon. During test occlusion, two additional patients had ischemic events that proved to be embolic; these reversed immediately upon balloon deflation. Of the 65 patients in whom permanent occlusion was effected by detachable balloon, there were nine instances of delayed cerebral events. One of these was a seizure leading to respiratory arrest and resuscitation 3 days following occlusion in a patient who had presented with seizures. The other eight cases were delayed ischemic events; seven were completely reversed and one patient had residual weakness in one leg (1.5% permanent morbidity). Extracranial-intracranial bypass procedures were performed in 25 of the 65 cases. All aneurysms of the carotid artery below the level of the ophthalmic artery presented angiographic proof of complete thrombosis. Ten of 21 aneurysms arising from the supraclinoid portion of the carotid artery were completely thrombosed by proximal occlusion alone, without additional trapping procedures. Similarly, in three of six basilar trunk aneurysms, proximal occlusion alone initiated complete aneurysm thrombosis without trapping. The conclusion is that proximal balloon occlusion for unclippable cerebral aneurysms is a convenient, safe, and effective way of producing arterial occlusion in these cases.