Embolization from a fusiform middle cerebral artery aneurysm

Characteristics and Clinical Course of Fusiform Middle Cerebral Artery Aneurysms According to Location, Size, and Configuration

OBJECTIVE

To analyze the angiographic features and clinical course, including treatment outcomes and the natural course, of fusiform middle cerebral artery aneurysms (FMCAAs) according to their location, size, and configuration.

METHODS

We reviewed the literature on adult cases of FMCAAs published from 1980 to 2018; from 25 papers, 112 FMCAA cases, for which the location, size, and configuration could be identified, were included in this study. Additionally, 33 FMCAA cases in our hospital were included, from which 16 were assigned to the observation group. Thus, a total of 145 adult FMCAA cases were included. We classified the FMCAAs according to their location (l-type 1, beginning from prebifurcation; l-type 2, beginning from bifurcation; l-type 3, beginning from postbifurcation), size (small, <10 mm; large, ≥10 mm; giant, ≥25 mm), and configuration (c-type 1, classic dissecting aneurysm; c-type 2, segmental ectasia; c-type 3, dolichoectatic dissecting aneurysm).

RESULTS

The c-type 3 was more commonly diagnosed with ischemic symptoms (31.8%) than hemorrhage (13.6%), while 40.9% were found accidentally. In contrast, c-type 2 was more commonly diagnosed with hemorrhagic symptoms (14.9%) than ischemic symptoms (10.6%), and 72.3% were accidentally discovered. According to location, ischemic symptoms and hemorrhage were the most frequent symptoms in l-type 1 (28.6%) and l-type 3 (34.6%), respectively. Most of l-type 2 FMCAAs were found incidentally (68.4%). Based on the size of FMCAAs, only 11.1% of small aneurysms were found to be hemorrhagic, while 18.9% and 26.0% of large and giant aneurysms were hemorrhagic, respectively. Although four aneurysms of the 16 FMCAAs in the observation group increased in size and one aneurysm decreased in size during the observation period, no rupture was seen in any case and there were no significant predictors of aneurysm enlargement. Of 104 FMCAAs treated, 14 cases (13.5%) were aggravated than before surgery and all the aggravated cases were l-type 1.

CONCLUSION

While ischemic symptoms occurred more frequently in l-type 1 and c-type 3, hemorrhagic rather than ischemic symptoms occurred more frequently in l-type 3 and c-type 2. In case of l-type 1 FMCAAs, more caution is required in determining the treatment due to the relatively high complication rate.

Thrombolysis in Acute Stroke Due to Thrombosed Aneurysm

We describe a case of a patient who presented with an acute stroke and thrombosed aneurysm of the same vessel. We review the literature on acute stroke management in the setting of an ischemic stroke caused by a thrombosed aneurysm, including intravenous thrombolysis and mechanical thrombectomy. We found that it is unclear whether thrombolysis is safe in these cases. Future case series may be helpful in answering the question.

Techniques and Outcomes of Gore-Tex Clip-Wrapping of Ruptured and Unruptured Cerebral Aneurysms

OBJECTIVE

Some aneurysms without a definable neck and associated parent vessel pathology are particularly difficult to treat and may require clipping with circumferential wrapping. We report the largest available contemporary series examining the techniques of Gore-Tex clip-wrapping of ruptured and unruptured intracranial aneurysms and patient outcomes.

METHODS

The presentation, location, and shape of the aneurysm; wrapping technique; outcome at discharge and last follow-up; and any change in the aneurysm at last angiographic follow-up were reviewed retrospectively in 30 patients with Gore-Tex clip-wrapped aneurysms.

RESULTS

Gore-Tex clip-wrapping was used in 8 patients with ruptured aneurysms and 22 patients with unruptured aneurysms. Aneurysms included 23 fusiform, 3 blister, and 4 otherwise complex, multilobed, or giant aneurysms. Of the 30 aneurysms, 63% were in the anterior circulation. The overall mean patient age was 52.5 years (range, 17-80 years). Postoperatively, there were no deaths or worsening of neurologic status and no parent vessel stenoses or strokes. The mean Glasgow Outcome Scale score at last follow-up was 4.7. The mean follow-up time was 42.3 months (median, 37.0 months; range, 3-96 months). There were 105.8 patient follow-up years. Aneurysms recurred in 2 patients with Gore-Tex clip-wrapping. No patients developed rehemorrhage. Overall risk of recurrence was 1.9% annually.

CONCLUSIONS

Gore-Tex has excellent material properties for circumferential wrapping of aneurysms and parent arteries. It is inert and does not cause a tissue reaction or granuloma formation. Gore-Tex clip-wrapping can be used safely for microsurgical management of ruptured and unruptured cerebral aneurysms with acceptable recurrence and rehemorrhage rates.

Techniques and long-term outcomes of cotton-clipping and cotton-augmentation strategies for management of cerebral aneurysms

OBJECTIVE To address the challenges of microsurgically treating broad-based, frail, and otherwise complex aneurysms that are not amenable to direct clipping, alternative techniques have been developed. One such technique is to use cotton to augment clipping ("cotton-clipping" technique), which is also used to manage intraoperative aneurysm neck rupture, and another is to reinforce unclippable segments or remnants of aneurysm necks with cotton ("cotton-augmentation" technique). This study reviews the natural history of patients with aneurysms treated with cotton-clipping and cotton-augmentation techniques. METHODS The authors queried a database consisting of all patients with aneurysms treated at Barrow Neurological Institute in Phoenix, Arizona, between January 1, 2004, and December 31, 2014, to identify cases in which cotton-clipping or cotton-augmentation strategies had been used. Management was categorized as the cotton-clipping technique if cotton was used within the blades of the aneurysm clip and as the cotton-clipping technique if cotton was used to reinforce aneurysms or portions of the aneurysm that were unclippable due to the presence of perforators, atherosclerosis, or residual aneurysms. Data were reviewed to assess patient outcomes and annual rates of aneurysm recurrence or hemorrhage after the initial procedures were performed. RESULTS The authors identified 60 aneurysms treated with these techniques in 57 patients (18 patients with ruptured aneurysms and 39 patients with unruptured aneurysms) whose mean age was 53.1 years (median 55 years; range 24-72 years). Twenty-three aneurysms (11 cases of subarachnoid hemorrhage) were treated using cotton-clipping and 37 with cotton-augmentation techniques (7 cases of subarachnoid hemorrhage). In total, 18 patients presented with subarachnoid hemorrhage. The mean Glasgow Outcome Scale (GOS) score at the time of discharge was 4.4. At a mean follow-up of 60.9 ± 35.6 months (median 70 months; range 10-126 months), the mean GOS score at last follow-up was 4.8. The total number of patient follow-up years was 289.4. During the follow-up period, none of the cotton-clipped aneurysms increased in size, changed in configuration, or rebled. None of the patients experienced early rebleeding. The annual hemorrhage rate for aneurysms treated with cotton-augmentation was 0.52% and the recurrence rate was 1.03% per year. For all patients in the study, the overall risk of hemorrhage was 0.35% per year and the annual recurrence rate was 0.69%. CONCLUSIONS Cotton-clipping is an effective and durable treatment strategy for intraoperative aneurysm rupture and for management of broad-based aneurysms. Cotton-augmentation can be safely used to manage unclippable or partially clipped intracranial aneurysms and affords protection from early aneurysm re-rupture and a relatively low rate of late rehemorrhage.

Unruptured cerebral aneurysms presenting with ischemic events

BACKGROUND

Patients harboring an unruptured cerebral aneurysm may present with ischemic events. The goal of this study is to assess the clinical and radiological characteristics and the outcome following treatment of these patients.

METHODS

The study population included 463 patients with unruptured cerebral aneurysms treated between January 2000 and November 2006. Patients with aneurysms manifesting with ischemic events were included. Outcome was assessed 12 months following aneurysm treatment using the modified Rankin scale.

RESULTS

Eleven patients were included in this series. An acute ischemic lesion in the symptomatic territory was demonstrated in six patients. The aneurysms were located on the internal carotid artery (n=4), middle cerebral artery (n=4), superior cerebellar artery (n=2) and basilar artery (n=1). They measured 10 mm or less (n=7); 11-20 mm (n=2); more than 21 mm (n=2). Five aneurysms were partially thrombosed on imaging. Five patients were referred for coiling. Of these, one patient had an unsuccessful coiling attempt, one had a residual neck, and three presented an aneurysm recurrence. Six patients were treated surgically. Symptomatic thromboembolism occurred after surgery in three patients. Complete aneurysm exclusion was documented in five of six operated patients. Nine of the ten treated patients had a favorable outcome.

CONCLUSION

Even though aneurysms presenting with ischemic events are often small and located on the anterior circulation, in this series the risk of thromboembolic events following aneurysm treatment is noteworthy. This information is relevant given the possible benign natural history in terms of stroke and risk of bleeding for some of these aneurysms.

Anévrysmes intracrâniens révélés par une ischémie cérébrale

PURPOSE

To report four cases of patient with an acute ischemic event as a presenting symptom of a berry aneurysm.

PATIENTS AND METHODS

One male and three female (aged range 38 to 65 years) patients were admitted for acute stroke. The neuroradiologic finding disclosed aneurysm thrombosis, inferior to twenty five millimetres in three cases. Lumbar puncture was done in one case and showed subarachnoid haemorrage.

DISCUSSION

We will discuss the hypothesis leading to the mechanism of aneurysm thrombosis. Two theories will be presented: "hemodynamic" and "parietal" modifications. We will propose a management protocol for these patients with atypical presentation of intracranial aneurysms given the potential risk of rupture.

CONCLUSION

The natural history of intracranial aneurysms is still not fully understood. Nevertheless, aneurym thrombosis may occur and lead to ischemic stroke.

Neurology case studies: cerebrovascular disease

Data from randomized therapeutic trials often provide little relevant evidence for therapeutic decisions physicians make daily. By illustrating the nuances of these four complex cases involving cerebrovascular disease, the authors stress the importance of more time spent by specialists at the bed-side, exploring patients' symptoms and learning their thoughts, fears, biases, and wishes.

The Natural History of Radiographically Defined Vertebrobasilar Nonsaccular Intracranial Aneurysms

BACKGROUND

Vertebrobasilar nonsaccular intracranial aneurysms (VBNIA) are characterized by dilatation, elongation, and tortuosity of the vertebrobasilar system.

METHODS

The medical records and imaging of patients with vertebrobasilar fusiform aneurysms or dolichoectasia between 1989 and 2001 were reviewed. Prospective follow-up was obtained.

RESULTS

One hundred and fifty-nine patients were identified (74% male) with 719 patient years of follow-up. Presenting events included: hemorrhage (3%), ischemia (28%), and compression (22%). The remainder were incidental. The 1-, 5-, and 10-year risk of cerebral infarction (CI) due toVBNIA is 2.7, 11.3, and 15.9% respectively. The risk of recurrent CI is 6.7% per patient year. Median survival was 7.8 years and death was most commonly due to ischemia.

CONCLUSIONS

VBNIA are more common in men and typically present in the 6-7th decade. Recurrent CI is more common than hemorrhage risk.

Enlarging vertebrobasilar nonsaccular intracranial aneurysms: frequency, predictors, and clinical outcome of growth

Object. Vertebrobasilar nonsaccular intracranial aneurysms (NIAs) are characterized by elongation, dilation, and tortuosity of the vertebrobasilar arteries. The goal of this study was to define the frequency, predictors, and clinical outcome of the enlargement of vertebrobasilar NIAs.

Methods. Patients with vertebrobasilar fusiform or dolichoectatic aneurysms demonstrated on imaging studies between 1989 and 2001 were identified. In particular, patients who had undergone serial imaging were included in this study and their medical records were retrospectively reviewed. Prospective information was collected from medical records or death certificates when available. Both initial and serial imaging studies were reviewed. The authors defined NIA enlargement as a change in lesion diameter greater than 2 mm or noted on the neuroradiologist's report. A Cox proportional hazards regression was used to model time from diagnosis of the vertebrobasilar NIA to the first documented enlargement as a function of various predictors. The Kaplan-Meier method was used to study patient death as a function of aneurysm growth.

Of the 159 patients with a diagnosis of vertebrobasilar NIA, 52 had undergone serial imaging studies including 25 patients with aneurysm enlargement. Lesion growth significantly correlated with symptomatic compression at the initial diagnosis (p = 0.0028), lesion type (p < 0.001), and the initial maximal lesion diameter (median 15 mm in patients whose aneurysm enlarged compared with median 8 mm in patients whose aneurysm did not enlarge; p < 0.001). The mortality rate was 5.7 times higher in patients with aneurysm growth than in those with no enlargement after adjustment for patient age (p = 0.002).

Conclusions. Forty-eight percent of vertebrobasilar NIAs demonstrated on serial imaging enlarged, and this growth was associated with significant morbidity and death. Significant risk factors for aneurysm enlargement included symptomatic compression at the initial diagnosis, transitional or fusiform vertebrobasilar NIAs, and initial lesion diameter. Further studies are necessary to determine appropriate treatments of this disease entity once enlargement has been predicted or occurs.

Prospective risk of hemorrhage in patients with vertebrobasilar nonsaccular intracranial aneurysm

Object. Nonsaccular intracranial aneurysms (NIAs) are characterized by dilation, elongation, and tortuosity of intracranial arteries. Dilemmas in management exist due to the limited regarding the natural history of this disease entity. The objective of this study was to determine the prospective risk of subarachnoid hemorrhage (SAH) in patients with vertebrobasilar NIAs.

Methods. All patients with vertebrobasilar fusiform or dolichoectatic aneurysms that had been radiographically demonstrated between 1989 and 2001 were identified. These patients' medical records were retrospectively reviewed. A prospective follow-up survey was sent and death certificates were requested. Based on results of neuroimaging studies, the maximal diameter of the involved artery, presence of SAH, and measurements of arterial tortuosity were recorded. Nonsaccular intracranial aneurysms were classified according to their radiographic appearance: fusiform, dolichoectatic, and transitional. Dissecting aneurysms were excluded. The aneurysm rupture rate was calculated based on person-years of follow up. Predictive factors for rupture were evaluated using univariate analysis (p < 0.05). One hundred fifty-nine patients, 74% of whom were men, were identified. The mean age at diagnosis was 64 years (range 20–87 years). Five patients (3%) initially presented with hemorrhage; four of these patients died during follow up. The mean duration of follow up was 4.4 years (692 person-years). Nine patients (6%) experienced hemorrhage after presentation; six hemorrhages were definitely related to the NIA. The prospective annual rupture rate was 0.9% (six patients/692 person-years) overall and 2.3% in those with transitional or fusiform aneurysm subtypes. Evidence of aneurysm enlargement or transitional type of NIA was a significant predictor of lesion rupture. Six patients died within 1 week of experiencing lesion rupture.

Conclusions. Risk of hemorrhage in patients harboring vertebrobasilar NIAs is more common in those with evidence of aneurysm enlargement or a transitional type of aneurysm and carries a significant risk of death.

Spontaneous fusiform middle cerebral artery aneurysms: characteristics and a proposed mechanism of formation

OBJECT

The goal of this study was to identify the origins of spontaneous fusiform middle cerebral artery (MCA) aneurysms.

METHODS

One hundred two cases of spontaneous fusiform MCA aneurysms were reviewed, including 40 from the authors' institutions and 62 identified from the literature. The mean age at symptom onset was 38 years, and the male/female ratio was 1.4:1. At presentation, the MCA lumen was stenosed or occluded in 12 patients, focally dilated in 57, and appeared "serpentine" in 33. Most lesions originated from the M1 or M2 segments, and most (80%) presented with nonhemorrhagic symptoms or were discovered incidentally. The presenting clinical features correlated with morphological findings in the aneurysms, which could be observed to progress from a small focal dilation or vessel narrowing to a serpentine channel. Hemorrhage was the most common presentation in small lesions; the incidence of bleeding progressively diminished with larger lesions. Patients with stenoses or occluded vessels most often presented with ischemic symptoms, and occasionally with hemorrhage. Giant focal dilations or serpentine aneurysms were rarely associated with acute bleeding; clinical presentation was most often prompted by mass effect or thromboembolic stroke.

CONCLUSIONS

Analysis of results after various treatments indicates that for symptomatic lesions, therapies that reverse intraaneurysmal blood flow and augment distal cerebral perfusion are associated with better outcomes than other strategies, including conservative management. Based on the spectrum of clinical, pathological, neuroimaging, and intraoperative findings, dissection is proposed as the underlying cause of these lesions.

Giant fusiform aneurysms in the middle cerebral artery presenting with hemorrhages of different origins. Report of three cases and review of the literature

Three cases of giant fusiform aneurysms in the middle cerebral artery (MCA) presenting with hemorrhages of different origins are reported, and appropriate literature is reviewed to investigate the characteristics of these lesions. Two patients had suffered a subarachnoid hemorrhage and the other had an intramural hemorrhage (dissection). Pathologically, these aneurysms presented with hemorrhages of different origins; classic rupture type (Case 1), dissection type (Case 2), and atherosclerosis-related thrombosis type (Case 3). Based on surgical and pathological investigations in these three cases and a review of the reported literature, the authors propose that giant fusiform aneurysms in the MCA are characterized by weaknesses in the internal elastic lamina with intimal thickening. Therefore, these lesions have the potential to present with hemorrhage in each of the three types. This finding indicates that there is a strong relationship between the pathological features of giant fusiform aneurysms and their clinical course, and that it is necessary to determine appropriate therapy for giant fusiform aneurysms in the MCA by evaluating cerebral blood flow, even if the lesions are found incidentally.

Ischemic events associated with unruptured intracranial aneurysms: multicenter clinical study and review of the literature

OBJECTIVE

To determine the prevalence, clinical characteristics, and long-term outcomes in cases involving transient ischemic attacks (TIAs) or ischemic strokes secondary to embolization from unruptured intracranial aneurysms.

METHODS

We identified all available patients with intracranial aneurysms and ischemic strokes in three university-affiliated hospitals, using either International Classification of Diseases-9th Revision codes or local registries. Patients with clinically or radiologically detected cerebral infarctions distal to intracranial aneurysms, in the absence of other causes for the infarctions, were included. An aneurysmal embolic source was considered highly probable by the primary neurosurgeon/neurologist in all cases. Follow-up data for the patients were acquired through reviews of clinical visits or telephone interviews. A review of the literature was performed to identify characteristics of previously reported patients.

RESULTS

Ischemic strokes or TIAs attributable to embolization from the aneurysmal sac were observed for 9 of 269 patients (3.3%) with unruptured aneurysms. Of these nine patients, five were women and four were men (mean age, 62 yr; age range, 45-72 yr). Symptomatic aneurysms were located in the middle cerebral artery (n = 4), internal carotid artery (n = 3), posterior cerebral artery (n = 1), or vertebral artery (n = 1). The mean maximal diameter was 12.5 mm (range, 5-45 mm). Six patients underwent surgical treatment, of whom two experienced postoperative cerebral infarctions referable to the distribution of the artery harboring the aneurysm. Two patients were treated with aspirin, and one patient received no treatment. The mean follow-up period was 38 months (range, 1-60 mo). None of the patients experienced additional ischemic events during the follow-up period. Among the 41 previously reported patients, conservative treatment was used for 20 patients (mean follow-up period, 50.7 +/- 44.5 mo). Four of the 20 patients experienced recurrent TIAs, 1 patient experienced worsening of symptoms, and 1 patient died during the follow-up period. A total of 21 patients underwent surgical treatment (mean follow-up period, 33.6 +/- 32.3 mo). Of these patients, only one experienced recurrent TIAs. Two patients experienced postoperative seizures, and one patient died during the follow-up period. All recurrent symptoms with either surgical or conservative treatment were transient, and no patient experienced a major or disabling stroke during the follow-up period.

CONCLUSION

Ischemic events can occur distal to both small and large unruptured intracranial aneurysms (predominantly in the anterior circulation). The long-term risk of recurrent ischemic events, particularly major or disabling strokes, seems to be low with either surgical or conservative treatment.

Delayed thrombus propagation after parent artery clipping for giant fusiform aneurysms of the circle of Willis

BACKGROUND

Obliteration of a giant fusiform aneurysm without significant therapeutic morbidity is extremely difficult. Ischemic complications have been often reported.

METHODS

Two patients with giant fusiform aneurysms of the circle of Willis are presented. Both patients underwent proximal parent artery clipping after a bypass procedure. Balloon occlusion tests confirmed both patients' ability to tolerate flow reduction after proximal clipping.

RESULTS

Although both patients awoke from anesthesia without neurologic deficit, they developed contralateral hemiparesis several hours after the operation as a result of a small infarct in the basal ganglia. These ischemic events might be attributed to the delayed thrombosis involving the orifice of the distal perforating arteries.

CONCLUSIONS

In the treatment for giant fusiform aneurysms of the circle of Willis, special attention should be paid not only to flow reduction, but also to delayed thrombus propagation that may not be predicted by preoperative balloon occlusion testing.

Giant fusiform aneurysm presenting as fatal basilar artery occlusion

Fusiform aneurysms are often asymptomatic, and therefore their actual incidence is unknown. Ischemic stroke has been linked to dislodgment of small thrombi formed inside the aneurysm but is uncommon. This article describes two patients with rapidly fatal infarction in the entire pons, both cerebellar hemispheres, thalamus, and occipital lobes, findings consistent with occlusion of the vertebrobasilar artery complex. In both patients, autopsies revealed a giant fusiform aneurysm of the basilar artery.

Anticoagulation for prevention of cerebral infarcts following subarachnoid hemorrhage

BACKGROUND

Late neurologic deterioration following subarachnoid hemorrhage is often due to vasospasm and rebleeding. Although the sudden onset of a focal neurologic deficit can actually be the result of thromboembolism, anticoagulation has rarely been used in such cases.

METHODS

We report a case of a 55-year-old woman who developed recurrent transient focal neurologic deficits 13 days after having a subarachnoid hemorrhage, with multiple cerebral infarcts by CT. Two cerebral angiograms showed no aneurysm. Her symptoms and clinical temporal profile were consistent with thromboembolic phenomenon. We elected to treat her with systemic anticoagulation.

RESULTS

The patient had no recurrent events after systemic anticoagulation, but had episodic sensory changes and a new infarct on MRI once the anticoagulation was discontinued.

CONCLUSIONS

Anticoagulant was safely administered after subarachnoid hemorrhage (SAH) in this patient and may have been effective in preventing further cerebral ischemic infarction following her SAH. Our patient's clinical profile of sudden (rather than gradual) onset of a transient focal neurologic deficit and resolution of blood on CT indicates one setting in which the use of heparin may be considered.

Treatment of fusiform intracranial aneurysms by circumferential wrapping with clip reinforcement. Technical note

The authors describe a new technique for treating unclippable aneurysms. The method involves a modification of the traditional wrapping technique, including a clip-reinforced cotton sling. The results of this method in four patients are presented.

Thrombosis of a giant aneurysm after extracranial-intracranial bypass

A patient presenting with a giant, fusiform middle cerebral artery aneurysm underwent extracranial to intracranial bypass grafting before permanent occlusion of the aneurysm. The patient was to return 4 months later for endovascular treatment. Arteriography obtained before obliteration revealed complete aneurysmal thrombosis. No further treatment was deemed necessary. Factors predisposing to thrombosis are discussed.

Positive platelet scintigram of a vertebral aneurysm presenting thromboembolic transient ischemic attacks

We describe a patient with transient ischemic attacks secondary to a giant aneurysm who showed increased activity on platelet scintigrams at the origin of the left vertebral artery. This is assumed to be the first report of a presumed embolizing aneurysm with positive activity of labeled platelets. Platelet scintigraphy is useful for diagnosing transient ischemic attacks as being secondary to an aneurysm and was proved to provide direct evidence of a thromboembolic source in vivo.

Unruptured aneurysms in patients with transient ischemic attack or reversible ischemic neurological deficit. Report of eight cases

Thirty-five patients with unruptured aneurysms were treated between 1981 and 1987. Eight of them had either transient ischemic attacks or reversible ischemic neurological deficits as their presenting symptoms. Six of the eight patients underwent direct aneurysm surgery. All eight patients are well, and have had no recurrent attack during the follow-up period ranging from 2 to 7 years. The feasibility of surgical treatment for such aneurysms associated with reversible ischemic symptoms is discussed.

Reconstruction of the MCA bifurcation after excision of a giant aneurysm. Technical note

A patient with a giant aneurysm of the left middle cerebral artery (MCA) presented with a history of subarachnoid hemorrhage and ischemic symptoms. When the aneurysm was explored, its base was found to be very firm and atherosclerotic. Temporary clips were applied to the MCA, the aneurysm was excised, and the MCA bifurcation was reconstructed using microsurgical techniques. Good flow in the reconstructed MCA trunk was demonstrated by intracranial Doppler ultrasonography. A description of the operative procedure is presented.

Fusiform intracranial aneurysms. Clinicopathologic features

Seven fusiform aneurysms were found at autopsy in five patients (two males and three females) over a 13-year period. The subjects were between 56 and 65 years of age. The basilar trunk was the most frequent site. Four aneurysms were of giant proportions and contained laminated thrombi. Subarachnoid hemorrhage occurred in four patients. Microscopic examination of the aneurysm walls revealed atheromatous degeneration, focal wall attenuation, mural hemorrhage, rupture, and acute and chronic inflammatory cell infiltration. These findings suggest that rupture is not rare and that atherosclerosis is but one mechanism in the pathogenesis of these lesions.

Multiple giant fusiform aneurysms with hydrocephalus

Multiple giant fusiform aneurysms are uncommon. We report such a case of multiple giant fusiform aneurysms involving both internal carotid arteries and the basilar artery associated with hydrocephalus. The neurological deficits presented in this case were due to pontine infarction, which was suspected to be produced by thrombosis from the aneurysm, and a hydrocephalus might have been caused by a "water-hammering" effect of the elongated basilar artery.

Transient neurological deficits secondary to saccular vertebrobasilar aneurysms. Report of two cases

Aneurysms have rarely been implicated as a possible cause of transient neurological deficits, and most reports of this phenomenon describe aneurysms in the anterior circulation. There is only one previous report of a saccular posterior circulation aneurysm associated with transient ischemic attacks. The authors document two cases of giant saccular vertebrobasilar artery aneurysms associated with transient neurological deficits.

Recurrent cerebral embolization from a carotid bifurcation aneurysm

In addition to heart disease and ulcers of the carotid artery, partially thrombosed large or giant aneurysms of the carotid territory may be the source of emboli into the middle cerebral distribution. Recurrent ischaemic attacks, characteristic of embolization, ceased after clipping of a sclerotic carotid bifurcation aneurysm that had never bled. Relevant literature is reviewed.

End-to-end anastomosis of the anterior cerebral artery after excision of a giant aneurysm. Case report

✓ A case of a giant anterior cerebral artery fusiform aneurysm is presented. The lesion was treated by primary excision of the involved segment with an end-to-end anastomosis of the proximal-distal segments of the anterior cerebral artery. It is believed that this technique has not been reported previously for lesions involving major intracranial arteries.