Ruptured Giant Left Distal Anterior Cerebral Artery Aneurysm in a Two-Month-Old Baby

BACKGROUND

The incidence of intracranial aneurysm in childhood is rare, especially in infancy. In the literature, most of childhood intracranial aneurysms occur in the posterior and middle cerebral circulation. We report a case of a ruptured giant left distal anterior cerebral artery aneurysm in a 2-month-old baby. This report will discuss the rarity of this case as well as the diagnostic and surgical challenges in treating this condition.

CASE REPORT

A 2-month-old baby girl presented to our centre with a 1-day history of multiple afebrile seizures. A CT scan of her brain showed a large frontal interhemispheric acute bleed with intraventricular extension and acute hydrocephalus. An external ventricular drain was inserted and she was nursed in the Paediatric Intensive Care Unit. Subsequent CT angiogram and 4-vessel angiogram showed a giant aneurysm originating from the A3 segment of the left anterior cerebral artery. She underwent craniotomy and clipping and excision of the giant aneurysm.

DISCUSSION

Giant distal anterior artery aneurysms are very rare in infants. They are more commonly associated with the posterior and middle cerebral arteries. The aneurysms in infants tend to be larger compared to adults and they commonly present with subarachnoid haemorrhage and seizures. CT angiogram and 4-vessel cerebral angiogram are important diagnostic tools in this case. The angiogram demonstrated no distal runoff from the aneurysm and this assisted in our planning for surgical treatment of the aneurysm. A bifrontal craniotomy was done and the giant aneurysm was approached interhemispherically. The proximal and distal parent vessel was clipped and the aneurysm wall was excised. The baby recovered from surgery and did not require any cerebrospinal fluid diversion.

CONCLUSION

Giant distal anterior cerebral artery aneurysms are rare in infants. Detailed angiographic investigation is important. Surgery is the treatment of choice, although there may be a role for endovascular intervention.

[Two cases of anterior cerebral artery aneurysm associated with accessory anterior cerebral artery: review of the literature and points of diagnosis]

The accessory anterior cerebral artery (AccACA) is an anomalous vessel arising from the anterior communicating artery. Although AccACA is not particularly rare, aneurysms arising from the AccACA is extremely rare. Here, we report two cases of unruptured AccACA aneurysms. Patient 1 was a 58-year-old woman with an unruptured distal AccACA aneurysm. Magnetic resonance imaging and three-dimensional computed tomography angiography(3D-CTA)demonstrated a left middle cerebral artery aneurysm that was subsequently clipped successfully by direct surgery. No aneurysm was detected in the distal anterior cerebral artery(ACA)due to the narrow imaging range at that time. Postoperatively, an aneurysm of the distal ACA was incidentally identified on 3D-CTA. This AccACA aneurysm was also clipped by direct surgery about 5 months later, and the patient was discharged without any neurological deficits. Patient 2 was a 46-year-old woman with an aneurysm at the proximal portion of the AccACA. Since the aneurysm was small and patient was asymptomatic, the observation-approach was selected. In introducing these cases, we discuss AccACA aneurysms and the process of diagnosis. Aneurysm can arise over the entire length of the ACA, from the anterior communicating artery to the peripheral portion, particularly the supracallosal portion, so observation and imaging of the peripheral region is important in cases where an AccACA is present.

[A case of STA-A3 bypass with a STA interposition graft and endovascular trapping for a ruptured A2 dissecting aneurysm]

A 57-year-old man presented with sudden-onset consciousness disturbance. He had a 10-year history of a subarachnoid hemorrhage(SAH)caused by a ruptured aneurysm in the right middle cerebral artery, and had undergone aneurysmal clipping. He could perform all his daily life activities independently. Computed tomography showed diffuse SAH with intraventricular hemorrhage. Digital subtraction angiography(DSA)demonstrated mild fusiform dilatation of the left A2 portion of the left anterior cerebral artery(ACA)and the terminal portion of the left internal carotid artery with no sign of right middle cerebral artery(MCA)aneurysm recurrence. We could not identify the bleeding lesion at that time; therefore, conservative treatment was selected in the acute phase. Fourteen days later, repeated DSA showed fusiform dilatation of the left A2 portion leading to a diagnosis of ACA dissection. We initially performed superficial temporal artery(STA)-ACA anastomosis and secondary internal trapping with detachable coils in the operating room. Postoperative DSA revealed complete obliteration of the dissection and parent artery. Endovascular treatment with STA-ACA bypass is a safe and effective alternative for the treatment of ACA dissection.

Microsurgical management of distal anterior cerebral artery aneurysms: from basic to complex, a video review of four cases

BACKGROUND

Distal anterior cerebral artery (DACA) aneurysms represent 2-9 % of intracranial aneurysms. They are often more amenable to surgical rather than endovascular treatment due to the size of parent vessels.

METHOD

We illustrate surgical approaches for DACA aneurysms arising from different segments of the anterior cerebral artery. Cases range from simple unruptured aneurysms to complex ruptured aneurysms requiring reconstruction and intracranial bypass.

CONCLUSION

The interhemispheric approach typically provides an adequate surgical corridor for surgical clipping of DACA aneurysms. Patient positioning, image guidance, and preoperative angiography help maximize safety and efficacy of surgery.

Microsurgical clipping of previously coiled aneurysms

OBJECTIVE

This study sought to show and analyze the main authors' experience (P.R. and J.M.C.) in previously coiled aneurysm surgery as an emerging challenge in today's neurosurgical practice.

METHODS

Twelve female and 8 male patients, whose ages ranged from 32 to 56 years (average 43.5), underwent surgery between April 2009 and September 2012 in 2 centers. Reasons for surgery were 13 partially occluded aneurysms and 7 recanalized aneurysms.

RESULTS

There was no mortality in this series. Aneurysmal sites were 5 anterior communicating artery aneurysms, 5 posterior communicating artery aneurysms, 3 middle cerebral artery aneurysms, 6 paraclinoid carotid artery aneurysms, and 1 aneurysm in the pericallosal artery. A patient sustained a postsurgical frontal infarction with mild neurological deficit. One of the aneurysms presented with an arterial branch at the level of the aneurysmal neck; therefore, partial clipping and packing was required. Microsurgical clipping in the remaining patients was performed successfully. Eight cases required partial coil removal before clipping.

CONCLUSIONS

Surgical management of previously coiled aneurysms is an emerging challenge in neurosurgery. Incomplete or ineffective embolizations pose an increased risk for the patient, thus requiring surgical treatment. Although not advisable, coil removal might be necessary when in the vicinity of the aneurismal neck in order to place the clip correctly. The authors believe that adequate patient selection and careful preoperative planning are essential to reduce the incidence of patients with unsuccessful coils who will later need surgical treatment.

[Azygos anterior cerebral artery aneurysm in a patient with Noonan syndrome]

Noonan syndrome(NS)is a common, clinically and genetically heterogeneous condition characterized by distinctive facial features, short stature, congenital heart disease, and other comorbidities. However, there have been only a few case reports of cerebrovascular abnormalities in patients with NS. Especially, the cases of intracranial aneurysms with NS are very rare. In addition, comorbidities of azygos anterior cerebral artery(ACA)and NS have not been reported before now. We encountered such a rare case of azygos ACA unruptured aneurysm in patient with NS. The case was 64-year-old woman with NS complaining of gait disturbance. The three-dimensional CT angiography(3D-CTA)showed azygos ACA and an unruptured saccular aneurysm at the distal end of the A2 segment. An operation for this aneurysm was performed. We reviewed clinical features of NS with cerebrovascular disease such as aneurysm.

[Microsurgical anatomy importance of A1-anterior communicating artery complex]

BACKGROUND

The anterior cerebral artery originates from the bifurcation of the internal carotid artery lateral to the optic chiasm, then joins with its contralateral counterpart via the anterior communicating artery. A1-anterior communicating artery complex is the most frequent anatomical variants and is the major site of aneurysms between 30 to 37%.

OBJECTIVE

Know the anatomy microsurgical, variants anatomical and importance of complex precommunicating segment-artery anterior communicating in surgery neurological of the pathology vascular, mainly aneurysms, in Mexican population.

METHODS

The study was performed in 30 brains injected. Microanatomy was studied (length and diameter) of A1-anterior communicating artery complex and its variants.

RESULTS

60 segments A1, the average length of left side was 11.35 mm and 11.84 mm was right. The average diameter of left was 1.67 mm and the right was 1.64 mm. The average number of perforators on the left side was 7.9 and the right side was 7.5. Anterior communicating artery was found in 29 brains of the optic chiasm, its course depended on the length of the A1 segment. The average length of the segment was 2.84 mm, the average diameter was 1.41 mm and the average number of perforators was 3.27. A1-anterior communicating artery complex variants were found in 18 (60%) and the presence of two blister-like aneurysms.

CONCLUSION

It is necessary to understand the A1-anterior communicating artery complex microanatomy of its variants to have a three-dimensional vision during aneurysm surgery.

[Saccular aneurysm arising in the non-branching segment of the distal anterior cerebral artery with stalk-like narrow neck: a case report]

An aneurysm arising in the distal anterior cerebral artery (DACA) is relatively rare. Among them, those in the non-branching segment are seldom reported so far. The authors present the case of an 87-year-old woman who developed intracerebral hemorrhage and acute hydrocephalus due to rupture of an aneurysm arising in the non-branching site of DACA. External ventricular drainage followed by aneurysm clipping by bifrontal craniotomy was performed as treatment. Microscopic observations revealed that the aneurysm was saccular-shaped, located at the non-branching site of the A3 portion of the anterior cerebral artery, and had significant atherosclerosis neither on its parent artery nor neck. Histopathological examinations of the aneurysm wall denied traumatic aneurysm or mycotic aneurysm, and showed partial disruption of the internal elastic lamina, suggesting a difference from common aneurysms arising at arterial branchings. Profound knowledge of this type of aneurysms would be useful in dealing with them at surgery.

Giant serpentine aneurysm of the distal anterior cerebral artery

We report a case of a 38-year-old man with a giant serpentine aneurysm arising from the distal anterior cerebral artery. This aneurysm grew from a fusiform aneurysm to a huge aneurysm within 5 months before manifesting as a mass lesion. The aneurysm was largely filled with thrombus, and 4 distal branches arose from the aneurysm dome. Selective balloon test occlusion of the distal anterior cerebral artery using an intravascular technique was performed to confirm the tolerance of the brain tissue. The balloon test occlusion elicited adequate leptomeningeal collateral circulation and no neurologic symptoms; thus, the aneurysm was treated with trapping and resection. The patient had no ischemic complications after the surgery and returned to his job 1 month later. No ischemia developed in the 2 years after surgery. Selective balloon test occlusion of the distal cerebral artery using an intravascular technique can be a very useful tool in planning the therapeutic strategy for a complicated distal cerebral aneurysm.

Hemodynamic improvement of anterior cerebral artery territory perfusion induced by bifrontal encephalo(periosteal) synangiosis in pediatric patients with moyamoya disease: a study with brain perfusion SPECT

OBJECTIVE

The reinforcement of the anterior cerebral artery (ACA) territory perfusion is important for the future intellectual functioning of pediatric moyamoya disease (MMD) patients. To evaluate the hemodynamic improvement of the ACA territory, bifrontal encephalogaleo-(periosteal)synangiosis [EG(P)S] combined with encephaloduroarteriosynangiosis (EDAS) was compared with EDAS alone in pediatric MMD patients using brain perfusion SPECT.

METHODS

Among 36 patients (M:F = 16:20; mean age, 9.5 ± 3.0 years) who were surgically treated for MMD, EDAS was performed in 17 patients, and EDAS with bifrontal EG(P)S in 19 patients. Hemodynamic parameters consisting of basal cerebral perfusion, acetazolamide-challenge stress perfusion, and cerebrovascular reserve index were estimated using brain perfusion SPECT and probabilistic perfusion maps for the ACA and middle cerebral artery (MCA) territories. Cerebral angiography was performed to confirm revascularization.

RESULTS

Both the EDAS only (p = 0.04) and EDAS with EG(P)S group (p < 0.001) had significant improvements in cerebrovascular reserve of the ipsilateral MCA territory. The EDAS with EG(P)S group had significant improvements, not only in basal perfusion of the ipsilateral ACA territory (p = 0.03) but also in the cerebrovascular reserve of the bilateral ACA territories (p < 0.01). In parallel with the hemodynamic changes assessed by brain perfusion SPECT, neovascularization was noted in the ipsilateral MCA territory in both the EDAS only and EDAS with EG(P)S group, and in the ipsilateral ACA territory in the EDAS with EG(P)S group on the postoperative cerebral angiography.

CONCLUSIONS

EDAS with bifrontal EG(P)S induces significant improvements in the ACA and MCA territories, while EDAS generates significant improvements in the MCA territory only.

[CSF leakage and anosmia in aneurysm clipping of anterior communicating artery by basal interhemispheric approach]

We studied the incidence of postoperative infection related to CSF leakage and anosmia in basal interhemispheric approach (BIH). Between April, 1990 to March, 2009, 142 cases of anterior communicating (Acom) aneurysm including both unruptured and ruptured have been treated by clipping surgery using BIH. We retrospectively obtained clinical informations from medical records and video records about infectious complications, CSF leakage of cerebrospinal fluid (CSF), olfactory dysfunction and intraoperative findings of damage to the olfactory nerve. In most cases (139 patients, 97%), frontal sinus were opened at craniotomy. Of all, CSF rinorrhea occurred in 4 cases (2.8%), and meningitis in 6 cases. There was only one patient who sufferd from meningitis due to CSF rinorrhea. All that patients recovered completely without deficit. Anosmia occurred in 6 cases (4.2%), and intraoperative injuries in 4 cases (2.8%). There was only one patient in whom anosmia was consistent with nerve injury. In conclusion, BIH is an appropriate procedure for infection risk control in Acom aneurysm surgery. It is difficult to avoid olfactory dysfunction completely, even if olfactory nerves are preserved in form.

Clipping of large and giant aneurysms of anterior circulation

AIM

Surgical outcome for giant intracranial aneurysms (GIA) is suboptimal. Reasons for higher complication rates in large and GIA surgery are the occlusion of perforators or parent arteries during aneurysm clipping, or prolonged temporary occlusion of main arteries. In this article, results of clipping of large and GIAs of anterior circulation are presented.

MATERIAL AND METHODS

Ten patients with large or GIAs in the anterior circulation were treated by clipping (10/19, 52%). The most common location was the middle cerebral artery (MCA, 5/10), followed by the anterior cerebral artery (ACA, 3/10), and internal carotid artery (ICA, 2/10). Five aneurysms were large (17-20 mm), five were giant (27-53 mm).

RESULTS

Uneventful aneurysm clipping was performed in eight, and cure was obtained in nine patients. Mortality and morbidity figures were 10% (1/10), and 0% (0/10), respectively. Mean follow up time is 2.8 years (range 1-10 years).

CONCLUSION

Clipping is still the most common surgical method of dealing with these lesions. Clipping of all large and giant aneurysms of anterior circulation was achieved in our patients with 10% mortality and 0% morbidity rates. These rates are similar to figures reported in previous series. Clipping of large and giant aneurysms is still the best definitive treatment, and is applicable in majority of the patients.

Endovascular treatment of A1 segment aneurysms of the anterior cerebral artery

Aneurysms of the A1 segment of the anterior cerebral artery (ACA) are rare and challenging to treat. We evaluated our experience of endovascular treatment in 11 patients with A1 segment aneurysms of ACA. Seven aneurysms were treated with coiling; three were treated with stent-assisted coiling and one was treated with balloon-assisted coiling. Endovascular treatments were technically successful and without complication. Follow-up examinations showed complete cure in all 11 patients.

Traumatic anterior communicating artery pseudoaneurysm with cavernous sinus fistula

A traumatic carotid-cavernous fistula and an intracranial pseudoaneurysm are uncommon but well-known complications of head trauma. A rare subtype of arteriovenous fistula may occur from a pseudoaneurysm of the anterior communicating artery (AcoA) instead of the internal carotid artery. We describe a patient with a traumatic pseudoaneurysm of the AcoA with a cavernous sinus fistula treated with endovascular treatment. A 68-year-old man presented with a severe head injury after a fall. Coronal view multiplanar reformatted images with contrast medium showed gradual expansion of the pseudoaneurysm of the AcoA and the enhanced area of the cavernous sinus. Five weeks after the injury, the patient had a subarachnoid hemorrhage. A cerebral angiogram showed a fistula between the pseudoaneurysm of the AcoA and the cavernous sinus. The AcoA, left anterior cerebral artery and part of the pseudoaneurysm were obliterated by coil embolization. A postoperative angiogram showed no flow through the pseudoaneurysm and the cavernous sinus fistula. A traumatic AcoA pseudoaneurysm with a cavernous sinus fistula may occur as an extremely rare complication of head injury.

The variations of the anterior choroidal artery: an intraoperative study

AIM

Increasing use of surgical magnification for operations in the territory of the anterior choroidal artery (AChA) has created a need for detailed knowledge of their anatomical variations. The aim of the present study is to examine the anatomical variations of the AChAin patients operated via pterional approach.

MATERIAL AND METHODS

The origin and branching pattern of AChAs were observed intraoperatively in 130 patients who were operated via a pterional approach at our center.

RESULTS

AChAs arose from the internal carotid artery (ICA) and distal to the posterior communicating artery (PCoA) at a ratio of 70%, from just distal to the original point of the PCoA in 20%, and from just proximal to the ICA bifurcation in 10% of the patients. In 95 cases, AChAs arose from the inferolateral aspect of the ICA in the posterolateral aspect in 27 and from its lateral part in 8 cases. AChAs were found as a single branch at the origins from ICA in 110 patients, as double in 17 cases and as triple in 3 patients.

CONCLUSION

Recognition of anatomical variations and microvascular relationships of AChA will allow neurosurgeons to construct a better and safer microdissection plan, to save time and can prevent postoperative neurological deficits.

Validity of the frontolateral approach as a minimally invasive corridor for olfactory groove meningiomas

BACKGROUND

Several approaches are described for olfactory groove meningiomas (OGMs) varying from a very wide bifrontal craniotomy to minimally invasive endoscopic techniques. The goal of this study was to evaluate the results of the frontolateral approach for olfactory groove meningioma. Pitfalls related to this corridor will be described. The impact of tumor size and encasement of the anterior cerebral artery complex on the degree of tumor removal will be described on the basis of experience with 18 cases.

METHODS

Eighteen patients with OGM underwent microsurgical removal using the frontolateral approach. A retrospective study was conducted by analyzing clinical data, neuroimaging studies, operative findings, clinical outcome, and degree of tumor removal.

FINDINGS

The patients were classified into group A with tumor size less than 4 cm in diameter (7 out of 18 cases, 38.9%) and group B with tumor size more than 4 cm in diameter (11 out of 18 cases, 61.1%). CSF rhinorrhea was observed in three patients (16.7%). Postoperative left frontal intracerebral hematoma occurred in one patient (5.6%) belonging to group A. In another patient (5.6%) belonging to group B, marked right frontal lobe swelling was evident after dural opening, which necessitated partial right frontal pole resection. Total tumor removal (Simpson grade 1 and 2) was achieved in 14 out of 18 patients (77.8%), while subtotal removal (Simpson grade 3 and 4) was achieved in 4 patients (22.2%). In the 14 patients in whom total removal was achieved, 7 belonged to group A (all 7 patients of group A with 100% removal), while the remaining 7 patients belonged to group B (7 out of 11 patients, 63.6% removal; one of them had anterior cerebral artery complex encasement). The four patients in whom subtotal removal was achieved belonged to group B; three of them showed anterior cerebral artery complex encasement, and one elderly patient had non-extensive paranasal sinus involvement. One patient (5.6%) in group B died from cerebral infarction after subtotal tumor removal with anterior cerebral artery injury during its dissection from the tumor capsule.

CONCLUSION

The frontolateral approach has the advantages of both the pterional and conventional bifrontal approaches. The frontolateral approach allows quick and minimally invasive access to OGMs less than 4 cm in diameter, and also to tumors more than 4 cm in diameter without encasement of the anterior cerebral artery complex. Tumor size more than 4 cm in diameter and encasement of the anterior cerebral artery complex are limiting factors for the frontolateral approach if radical tumor removal is considered.

"Phosphene": early sign of vascular compression neuropathy of the optic nerve

BACKGROUND

Phosphenes, flashes of light, are a visual phenomenon experienced by patients with ophthalmological disease and normal individuals.

CASE REPORT

We report here a 68-year-old woman in whom phosphenes appeared in the left visual field due to compression of the right optic nerve by an aneurysm of the anterior communicating artery.

RESULTS

The symptom decreased dramatically after clipping of the aneurysm.

CONCLUSION

Phosphenes may be an important early sign of vascular compression neuropathy of the optic nerve.

Cerebral aneurysm associated with an intracranial tumour: staged endovascular and surgical treatment in two cases

Two cases are reported in which an anterior communicating artery aneurysm was associated with an intracranial tumour. The tumour was a suprasellar meningioma in one case and an optic chiasm/hypothalamic astrocytoma in the other. In both cases, the aneurysm was successfully embolized using Guglielmi detachable coils. Subsequently craniotomy was performed with complete excision of the meningioma and subtotal removal of the astrocytoma. Endovascular techniques can be employed to make the surgical excision of an intracranial tumour co-existing with an incidental aneurysm safer.

Aberrant internal carotid artery in the middle ear with a deficiency in the origin of the anterior cerebral artery: a case report

An aberrant internal carotid artery (ICA) in the middle ear is rare and difficult to diagnose, and may lead to severe complications. We present here a case of aberrant ICA with a deficiency in the origin of the anterior cerebral artery. The only symptom was aural fullness, and a nonpulsatile and white tympanic mass in the anteroinferior area was noted. Computed tomography (CT) and magnetic resonance angiography (MRA) are useful tools that provide excellent visualization of the temporal bone for the diagnosis of aberrant ICA by the following features: intratympanic mass, enlarged inferior tympanic canaliculus, absence of the vertical segment of the ICA canal, and absence of bone covering the tympanic portion of the ICA. In addition, in this case, a deficiency in the origin of the anterior cerebral artery on the same side was identified by MRA, and cerebral arteriography and a carotid occlusion test were performed. Because of the deficiency in the origin of the anterior cerebral artery, the ICA compression revealed that there was almost no cross flow from the other ICA. Our experience illustrates that after confirmation of the diagnosis of aberrant ICA, localized treatment and/or surgical procedures should be considered carefully.

Infraoptic anterior cerebral artery: review, report of two cases and an anatomical classification

INTRODUCTION

Infraoptic course of the pre-communicating anterior cerebral artery (A1) is a rare anomaly. In total, there are 42 examples reported in the literature. We report two further patients. The first had an intradural cerebral aneurysm at the low bifurcation of an internal carotid artery (ICA) with bilateral infraoptic course of A1. The second had right infraoptic course of A1 with associated left parietal cerebral arteriovenous malformation and is the first report of such an association.

DISCUSSION AND CONCLUSION

Overall, 59% of the examples were associated with cerebral aneurysms. Different terminology such as carotid-anterior cerebral artery anastomosis and infraoptic anterior cerebral artery has been used. Having analyzed the reports of infraoptic A1, we found the vascular configurations of the A1 could be better described by classifying them into four types. Such a classification can facilitate analysis of the embryogenesis explanation for this anomaly and the pathogenesis of the associated aneurysms. Besides, such a classification also has some practical implications.

Microneurosurgical management of aneurysms at the A2 segment of anterior cerebral artery (proximal pericallosal artery) and its frontobasal branches

BACKGROUND

Aneurysms originating from the A2 segment of ACA and its frontobasal branches are rare, forming less than 1% of all IAs. There are only few reports on management of A2As. In this article, we review the practical anatomy, preoperative planning, and avoidance of complications in the microsurgical dissection and clipping of A2As.

METHODS

This review, and the whole series on IAs, is mainly based on the personal microneurosurgical experience of the senior author (JH) in two Finnish centers (Helsinki and Kuopio), which serve, without patient selection, the catchment area in Southern and Eastern Finland.

RESULTS

These two centers have treated more than 10000 patients with IAs since 1951. In the Kuopio Cerebral Aneurysm Database of 3005 patients and 4253 IAs, there were 35 patients carrying 35 A2As, forming 1% of all patients with IAs, 0.8% of all IAs, and 3% of all ACA aneurysms. Twenty-one (60%) patients presented with ruptured A2As with ICH in 11 (52%) and IVH in 7 (33%). Nineteen patients (54%) had multiple aneurysms.

CONCLUSIONS

A2As are often small, even when ruptured, with relatively wide base, and they are frequently associated with ICHs of IVHs. Our data suggest that A2As rupture at smaller size than IAs in general. The challenge is to select appropriate approach, locate the aneurysm deep inside the interhemispheric fissure, and to clip the neck adequately without obstructing branching arteries at the base. Unruptured A2As also need microneurosurgical clipping even when they are small.

Horizontal contralateral approach for the distal anterior cerebral artery aneurysm: technical note

BACKGROUND

The authors present a modified interhemispheric approach for the distal ACA aneurysm to resolve several problems including the narrow surgical corridor, the difficulty of proximal control, and the aneurysmal projection toward the surgeon.

METHODS

We refined the positions of the patient's head and the surgeon. The patient's head is fixed with flexion and tilted to the contralateral side. The surgeon sits on the contralateral side of the patient and not on the cranial side.

RESULTS

The present approach allows the surgeon to comfortably use both hands in the horizontal operative filed, to obtain a minimum retraction of the brain, and to easily secure the proximal artery.

CONCLUSIONS

This modified interhemispheric approach is useful for a patient with the distal ACA aneurysm.

Microneurosurgical management of proximal anterior cerebral artery aneurysms

BACKGROUND

Aneurysms originating from the proximal segment of anterior cerebral artery (A1As) are rare, forming less than 1% of all IAs. There are only few reports on microneurosurgical management of A1As. In this article, the authors review the practical anatomy, preoperative planning, and avoidance of complications in the microsurgical dissection and clipping of A1As.

METHODS

This review, and the whole series on IAs, is mainly based on the personal microneurosurgical experience of the senior author (JH) in 2 Finnish centers (Helsinki and Kuopio), which serve without patient selection the catchment area in Southern and Eastern Finland.

RESULTS

These 2 centers have treated more than 10,000 patients with aneurysm since 1951. In the Kuopio Cerebral Aneurysm Database of 3005 patients with 4253 aneurysms, there were 23 patients carrying 23 A1As, forming 0.8% of all patients with aneurysm, 0.5% of all aneurysms, and 2% of all ACA aneurysms. Twelve (52%) patients presented with ruptured A1As with ICH in 3 (25%) and IVH in 2 (17%). Seventy percent of patients had at least 1 associated aneurysm.

CONCLUSIONS

Aneurysms arising from A1 are usually small, with a fragile wall. Our data suggest that A1As rupture at smaller size than IAs in general. Because of their small size and involvement of perforating arteries at their base, microneurosurgical clipping is the method of choice in treatment of ruptured A1As. Unruptured A1As also need microneurosurgical clipping even when they are small.

Ruptured fusiform aneurysm of the proximal anterior cerebral artery (A1 segment)

A 42-year-old man presented with a ruptured fusiform aneurysm of the proximal anterior cerebral artery (A(1) segment) manifesting as sudden onset of severe headache. Brain computed tomography revealed subarachnoid hemorrhage in the basal cisterns, and left carotid angiography demonstrated a fusiform aneurysm of the left A(1) segment. He underwent surgery via the left pterional approach. The left A(1) segment exhibited a fusiform configuration. Adequate development of the anterior communicating artery was confirmed. Trapping of the aneurysm was performed. The aneurysm was associated with atherosclerotic changes. The postoperative course was uneventful, and the patient was discharged without neurological deficits 1 month after surgery. Fusiform aneurysm of the A(1) segment is quite rare, and tends to bleed, so must be treated. The atherosclerotic origin indicates long-term follow up to identify subsequent lesions.