Aneurysm at the origin of accessory middle cerebral artery associated with middle cerebral artery aplasia: case report

Anterior cerebral artery dissection for a patient with ipsilateral aplastic or twig-like middle cerebral artery: An illustrative case report

Background

An aplastic or twig-like middle cerebral artery (Ap/T-MCA) is a rare anomaly, which sometimes causes ischemic infarction. Collateral flow from the ipsilateral anterior cerebral artery (ACA) is important for patients with Ap/T-MCA. If ipsilateral ACA stenosis or occlusion occurs, a large infarction with a wider field than the ACA territory could happen. First, mechanical thrombectomy was performed for the right ACA near occlusion caused by arterial dissection with ipsilateral Ap/T-MCA in this case. Second, Wingspan stenting was performed for the right ACA restenosis.

Case Description

A 77-year-old female presented to the hospital with the left hemiparesis. We diagnosed a right ACA infarction caused by right ACA occlusion. Digital subtraction angiography showed right Ap/T-MCA and ipsilateral ACA near occlusion. Thrombectomy was performed, and recanalization was achieved with mild ACA stenosis. The lesion was the dissection due to angiographical finding. Two months after treatment, transient left hemiparesis occurred and right ACA stenosis progressed. Computed tomography perfusion showed hypoperfusion of the right hemisphere. Wingspan stenting was performed from the left internal carotid artery through the anterior communicating artery with an intermediate catheter. The patient was discharged without any neurological deficit.

Conclusion

We reported the first case of a patient who underwent Wingspan stenting for the right ACA dissection with Ap/T-MCA. Short-term follow-up and aggressive intervention should be considered for collateral pathway dissection with Ap/T-MCA because the symptoms can become serious. The patients with Ap/T-MCA should be cautious about the collateral pathway arterial changes in particular ipsilateral ACA due to the increasing hemodynamic stress.

Case report: Endovascular coil embolization of an aneurysm at the origin of the accessory middle cerebral artery from the A1 segment as the collateral artery to twigs

An aneurysm at the origin of the accessory middle cerebral artery (AccMCA) from the A1 segment of the anterior cerebral artery (ACA) as the supplying artery of a twig-like MCA is exceptional. In this study, we reported on such a case and presented a review of the relevant literature. A 56-year-old male suffered a subarachnoid hemorrhage. Digital subtraction angiography confirmed a twig-like MCA and a ruptured aneurysm at the origin of the AccMCA. Endovascular coil embolization of the aneurysm was performed. After the microcatheter was positioned in the aneurysm, soft coils were delivered to complete the embolization. Postoperatively, the patient recovered uneventfully. One month later, the patient returned to his job without any neurological deficits. Postoperative computed tomography at the 3-month follow-up showed that the brain tissue was normal. By reporting our case and reviewing the relevant literature, we found that endovascular coil embolization for such aneurysms at the AccMCA origin is feasible in certain cases.

Ruptured aneurysm associated with a twig-like middle cerebral artery: An illustrative case report

Background:

Anomalies of the middle cerebral artery (MCA) are rare; among the different types of anomalies, the aplastic or twig-like (Ap/T) MCA is extremely rare and has been reported under various names, including aplastic, unfused, or rete type anomaly. The occurrence of a brain aneurysm associated with this anatomic variant is an even rare event, and probably their development and rupture are related to hemodynamic stress of the tinny wall of vessels forming the network.

Case Description:

We present a 43-year-old male patient with an explosive and persistent right orbitofrontal headache. A computed tomography showed a right frontobasal hematoma with intraventricular disruption. Magnetic resonance angiography showed a right MCA aneurysm and what seems to be a MCA trunk stenosis. Cerebral digital subtraction angiography demonstrated a plexiform arterial network and one aneurysm arising from the network. The patient was successfully treated by surgical clipping to evacuate the hematoma and to prevent further intracranial hemorrhages.

Conclusion:

The Ap/T-MCA may be associated with hemodynamic stress with a significant effect through the tinny wall of the vessels causing hemorrhage or leading to the formation and rupture of cerebral aneurysms. Based on a correct diagnosis of the anomaly, treatment can be completed successfully through different standard methods.

The Clinical Characteristics and Treatment Considerations for Intracranial Aneurysms Associated With Middle Cerebral Artery Anomalies: A Systematic Review

Background: As a result of their low incidence, most of the studies on intracranial aneurysms associated with middle cerebral artery (MCA) anomalies were presented as case reports or small case series. No systematic review on this specific entity has been conducted.

Methods: A PubMed search of the published studies was performed on April 6th, 2019 for patients who had intracranial aneurysms associated with MCA anomalies. The languages included in this study were English, Chinese, and Japanese.

Results: Finally, 58 articles reporting of 67 patients including 1 case in our center were included. The identified patients (37 females, 55.2%) aged from 4 to 81 (49.85 ± 15.22) years old. 50 (50/67, 74.6%) patients presented with hemorrhagic stroke either from the MCA anomalies associated aneurysms or other sources. 63 aneurysms (63/67, 94.0%) were saccular, 3 (4.5%) were dissecting or fusiform, and 1 (1.5%) was pseudoaneurysm. 32 (32/65, 49.2%) patients had other concurrent cerebrovascular anomalies. 56 (83.6%) patients underwent open surgeries, 8 (11.9%) patients underwent endovascular treatment, and 3 (4.5%) patients were conservatively managed. 56 (56/61, 91.8%) patients achieved a good recovery.

Conclusions: The pathophysiological genesis of intracranial aneurysms associated with MCA anomalies is still obscure. The inflicted patients tend to have other concurrent cerebrovascular anomalies, which denotes that congenital defect in cerebrovascular development might play a role in this process. Most of the affected patients could experience a good recovery after treatment.

Rete middle cerebral artery anomalies: a unifying name, case series, and literature review

OBJECTIVE

Rete middle cerebral artery (MCA) is extremely rare and has not been frequently discussed. Rete MCA is a weblike anomaly of the MCA that does not coalesce and forms a prominent, large single branch from the plexiform vessels in the fetal stage. The purpose of this study was to further elucidate the clinical and radiological characteristics of patients with rete MCA.

METHODS

A total of 2262 cerebral digital subtraction angiography procedures were performed on 1937 patients at the authors' institution from February 2013 to May 2017. Data analysis included age, sex, clinical symptoms, underlying diseases, coexisting cerebral arterial anomalies, and operative methods and findings.

RESULTS

Rete MCAs were found in 13 patients, and the incidence of this anomaly was 0.67% (13 of 1937) in this study. Of the 13 patients, 3 had hemorrhagic strokes, 6 had ischemic strokes, and 4 had no symptoms. Eight patients underwent conservative treatment, and 5 patients underwent surgical treatment. Rete MCA is considered a congenital disease of the cerebral vasculature with the possibility of an acquired abnormality, such as an aneurysm, caused by hemodynamic stress. Although an epidemiological survey of rete MCA was not conducted, it is assumed that rete MCA has a high prevalence in Asia. Ischemic and hemorrhagic stroke events are fairly common in rete MCA.

CONCLUSIONS

Clinicians should understand the radiological and clinical features of patients with rete MCA to avoid misdiagnosis and unnecessary treatment. This anomaly should be differentiated from other vascular diseases and patients presenting incidentally should be carefully monitored because of their vulnerability to both hemorrhagic and ischemic strokes.

Accessory middle cerebral artery associated with an unruptured aneurysm at its origin

BACKGROUND

An aneurysm originating from the junction of the A1 segment of the anterior cerebral artery and accessory middle cerebral artery (Acc-MCA) is markedly rare. We report a rare case of an Acc-MCA aneurysm, and discuss the clinical course and management of this rare condition.

CASE DESCRIPTION

A 64-year-old man with a past history of cerebral infarction was revealed to have a left Acc-MCA and an aneurysm at its origin. The aneurysm was clipped via a transsylvian approach. Due to its location and projectile direction, the neck of the aneurysm was left partially unclipped.

CONCLUSION

Although an Acc-MCA aneurysm is very rare, it has a potential risk of rupture. Therefore, radical treatment is necessary for such aneurysms.

Flow-related intracranial aneurysms associated with unfused arterial twigs relevant to different vascular anomalies: embryologic and hemodynamic considerations

OBJECT

Cerebrovascular anomalies resulting from the persistence of unfused embryonic twig-like vessels are associated with intracranial aneurysms. All records of patients with ruptured intracranial aneurysms who were treated at our institution were retrospectively reviewed for the presence of aneurysm-associated, unfused, twig-like vessels in the middle cerebral artery (MCA). Such vessels were recorded as twig-like MCA (T-MCA) or twig-like networks of an anomalous collateral artery (T-NACA). Additionally, we sought to characterize vulnerable intracranial aneurysms associated with those vascular anomalies.

METHODS

A total of 442 ruptured aneurysms were treated from June 2006 to November 2013; of these, 4 ruptured aneurysms exhibited the presence of ipsilateral, unfused, twig-like vessels. Computed tomography (CT) scans, three-dimensional CT angiography, and digital subtraction angiography (DSA) were performed immediately after the initial ictus. Data analysis included age, sex, Hunt and Hess grade (HHG), Fisher grade (FG), medical risk factors, angiographic architecture, operative methods and findings, radiologic outcomes, and Glasgow outcome scale (GOS). The average follow-up period was 26 months.

RESULTS

Patient ages ranged from 26 to 49 years with a mean age of 41; there were two females and two males. All four patients showed FG IV, and three patients had unfavorable HHG (IV in 2 and V in one) at admission. An M1 segmental occlusion and an adjacent small aneurysmal pouch were detected with three-dimensional CT angiography in three patients. Hypertension was recorded in all patients. The initial DSA revealed T-MCA in one patient and T-NACA in three patients. Six aneurysms in all, including two unruptured aneurysms, were found; three ruptured aneurysms existed inside of the twigs. All but one patient required diverse treatment modalities, and four of the five aneurysms were completely occluded after treatment. The remaining aneurysm, treated only with gluing, disappeared during follow-up. In two of the three patients with T-NACA, atresia of the M1 segment was confirmed intraoperatively. The GOS during follow-up was recorded as favorable (good recovery) in two patients and unfavorable (severe disability and permanent vegetative state) in two patients.

CONCLUSIONS

These unique vascular anomalies, T-MCA and T-NACA, which are caused by heterogeneous maldevelopment of the primitive cerebral vessels, are not benign because of their frequent association with flow-related aneurysms, which are vulnerable to rupture. Microsurgical or endovascular treatments for this type of flow-related aneurysm associated with twigs are mandatory to prevent fatal rebleeding, and more attention has to be given when physicians encounter steno-occlusive MCA lesions in patients with subarachnoid hemorrhage to detect any vulnerable aneurysms associated with twig-like vessels.

Unusual hemodynamic stroke related to an accessory middle cerebral artery: The usefulness of fusion images from three-dimensional angiography

BACKGROUND

Ischemic stroke associated with an anomaly of the middle cerebral artery (MCA) is a rare occurrence. The diagnosis is very difficult when there are steno-occlusive lesions associated with an accessory middle cerebral artery (AMCA).

CASE DESCRIPTION

A 77-year-old female with hypertension and hyperlipidemia experienced repeated transient ischemic attacks (TIAs) of motor aphasia and dysarthria. Although angiography showed only left intracranial occlusion, the fusion images of three-dimensional digital subtraction angiography (3-D DSA) showed complex steno-occlusive lesions and an AMCA related with the TIA. The cerebral blood flow (CBF) to the left frontal lobe was supplied by the AMCA, via the anterior communicating artery from the right internal carotid artery. The left temporal and parietal lobes were supplied by the stenotic MCA, via the left posterior communicating artery from the left posterior cerebral artery. Single-photon emission computed tomography showed a marked decrease in CBF to both the left frontal and temporal lobes. A left superficial temporal artery (STA)-to-left MCA double anastomosis was performed, in which each branch of the STA supplied branches of the AMCA and MCA.

CONCLUSION

This is the first reported case of ischemic stroke in a patient with an AMCA. The exact diagnosis could be made only by using fusion images of 3-D DSA, which were useful for understanding the complicated CBF pattern and for the choice of recipient artery in bypass surgery.

A ruptured aneurysm located at a collateral artery that extended from the proximal A2 segment to the M1 segment, associated with an anomalous branch of the anterior choroidal artery and middle cerebral artery hypoplasia: case report

We here describe the first case of a ruptured aneurysm located at a collateral artery that extended from the proximal A2 segment to the M1 segment, which was associated with an anomalous branch of the anterior choroidal artery and middle cerebral artery (MCA) hypoplasia. The aneurysm was revealed by angiograms and intraoperative findings. No previous accounts have been published of such an extremely rare vessel anomaly. In practice, this case highlights the urgent need to preoperatively recognize such vascular anomalies, as well as to better understand the collateral blood supply in cerebral ischemia associated with these MCA anomalies. Such knowledge will be helpful for planning optimal surgical procedures.

Clinical and Radiological Features of Patients With Aplastic or Twiglike Middle Cerebral Arteries

BACKGROUND:

An aplastic or twiglike middle cerebral artery (Ap/T-MCA) is an extremely rare congenital anomaly related to interference in the normal embryonic development of the MCA.

OBJECTIVE:

To evaluate the clinical and radiological features of patients with an Ap/T-MCA.

METHODS:

A total of 1749 conventional cerebral angiography procedures were performed in 1282 patients from January 2005 to July 2011 at Daegu Fatima Hospital. The images were evaluated for cerebral arterial anomalies. The radiological features of an Ap/T-MCA, coexisting anomalies, and clinical manifestations were recorded. These prospectively maintained databases were analyzed retrospectively.

RESULTS:

Ap/T-MCAs were found in 15 patients (1.17% angiographic incidence). The anomalies were confined to unilateral M1 segment, and no stenoses were seen in the adjacent major arteries. Of 15 patients, 6 (40%) had hemorrhagic strokes, 5 (33.3%) had ischemic strokes, and 4 (26.7%) had no symptoms. Aneurysms were found in 5 patients (33.3%). Coexisting cerebral arterial anomalies were seen in 12 patients (80%). Ten patients underwent conservative treatments, and the remaining 5 underwent surgical treatments, such as hematoma aspiration, indirect revascularization, and clipping or coiling of aneurysms.

CONCLUSION:

An Ap/T-MCA is a rare anomaly and should be differentiated from moyamoya conditions and degenerative steno-occlusive diseases of the middle cerebral artery. Coexisting anomalies of the anterior or middle cerebral arteries are frequent. This anomaly is vulnerable to both hemorrhagic and ischemic strokes.

Ruptured anterior cerebral artery aneurysm at the origin of the accessory middle cerebral artery

A 36-year-old female patient was admitted to our hospital with a rare case of aneurysm at the origin of the accessory middle cerebral artery (MCA) manifesting as severe headache and vomiting. Neurological examination did not detect any abnormalities or consciousness disturbance. Computed tomography demonstrated diffuse subarachnoid hemorrhage. Magnetic resonance angiography showed an aneurysm in the horizontal portion of the left anterior cerebral artery (A(1)). Digital subtraction angiography and three-dimensional digital subtraction angiography demonstrated a saccular aneurysm originating at the junction of the left A(1) and accessory MCA. Another accessory MCA originated at the proximal portion of the left A(2) without an aneurysm. Two accessory MCAs were found on the left. Neck clipping was performed via a left pterional approach. One month after admission, she was discharged without neurological deficits.

Ruptured aneurysm at an anastomotic artery extending from the vertebral artery to the posterior inferior cerebellar artery: a case report

A 51-year-old hypertensive man presented with subarachnoid haemorrhage. He had a past history of cerebellar infarction due to occlusion of the right posterior inferior cerebellar artery (PICA) 4 years earlier. Digital subtraction angiography showed a saccular aneurysm above an arterial loop extending from the vertebral artery to the distal part of the PICA, reminiscent of peripheral PICA branches. We performed aneurysmal neck clipping with excellent outcome. Aneurysms at anastomotic arteries are extremely rare and can result from increased haemodynamic stress. We report the first case of a ruptured aneurysm at an anastomotic artery in the posterior circulation territory.

A ruptured internal carotid artery aneurysm located at the origin of the duplicated middle cerebral artery associated with accessory middle cerebral artery and middle cerebral artery aplasia

Background:

Intracranial vascular anomalies involving the middle cerebral artery (MCA) are relatively rare, as such knowledge will be helpful for planning the optimal surgical procedures.

Case Description:

We herein present the first case of a ruptured internal carotid artery aneurysm arising at the origin of the hypoplastic duplicated MCA associated with accessory MCA and main MCA aplasia, which was revealed by angiograms and intraoperative findings.

Conclusion:

In practice, this case highlights the urgent need to preoperatively recognize such vascular anomalies as well as understand the collateral blood supply in cerebral ischemia associated with these MCA anomalies.

Endovascular treatment of a ruptured accessory middle cerebral artery aneurysm

A 51-year-old female presented with bilateral accessory middle cerebral arteries (MCA) with associated ruptured aneurysm manifesting as a subarachnoid hemorrhage. Angiography demonstrated the bilateral accessory MCA and associated ruptured aneurysm at the junction of the left anterior cerebral artery and left accessory MCA. This was successfully treated by coil embolization. Magnetic resonance angiography obtained 6 months later revealed no evidence of residual or recurring aneurysm.

Saccular aneurysm at the anterior communicating artery complex associated with an accessory middle cerebral artery : report of two cases and review of the literature

Accessory middle cerebral artery (MCA) is an infrequent vascular anomaly of the brain. Cerebral aneurysms associated with this anomalous artery are also very rare. To our knowledge, there have only been ten previous reports of an aneurysm associated with accessory MCA. The authors present two patients with accessory MCA-related aneurysms. A 38-year-old male and a 59-year-old female both presented with sudden-onset severe headache. In both patients, computed tomography (CT) scan revealed subarachnoid hemorrhage. A subsequent angiogram demonstrated an accessory MCA arising from the anterior cerebral artery (ACA) and a saccular aneurysm at the anterior communicating artery (ACoA) complex associated with an accessory MCA. Surgical clipping allowed for complete exclusion of the aneurysm from the arterial circulation. Based on our review of the ten cases of aneurysms associated with accessory MCA documented in the literature, we suggest that accessory MCA-related aneurysms can be classified according to whether the accessory MCA originates from the proximal A1 segment or from the ACoA complex. We also emphasize the importance of precise interpretation of preoperative angiograms and intraoperative precaution in determining the presence of this anomalous artery prior to temporary clip placement.

The angiographic feature and clinical implication of accessory middle cerebral artery

OBJECTIVE

Although there are several descriptions of this vessel, there is no detailed angiographic study of the accessory middle cerebral artery (AMCA) in Korea. We describe the angiographic characteristics of the cortical territory and origin of AMCA and discuss the clinical significance of this anomaly.

METHODS

We searched for patients with AMCAs from a retrospective review of 1,250 conventional cerebral angiograms. We determined the origins, diameters and cortical territories of these AMCAs.

RESULTS

Fifteen patients (15 of 1250 = 1.2%) had 16 AMCAs (one patient had bilateral AMCAs). AMCAs originated from the distal A1 in eleven cases, middle A1 in two, proximal A1 in two, and proximal A2 in one case. All AMCAs followed a course parallel to the main middle cerebral artery (MCA). All but three of these arteries were smaller than the main MCA. Thirteen of the smaller diameter AMCAs had cortical distribution to the orbito-frontal and prefrontal, and precentral areas. Three AMCAs had diameter as large as the main MCA. These three supplied the orbitofrontal, prefrontal, precentral, central and anterior-parietal arteries.

CONCLUSION

The AMCAs originated from A1 or A2. Most had smaller diameter than the main MCA. The AMCAs coursed along the horizontal portion of the MCA, but supplied the orbital surface, the anterior frontal lobe and sometimes wider cortical territory, including the precentral, central, anterior-parietal areas.

Microsurgical and Angiographic Anatomy of Middle Cerebral Artery Aneurysms: Prevalence and Significance of Early Branch Aneurysms

Objective:

To determine the prevalence of early branch aneurysms, characterize these lesions angiographically and anatomically, and determine their clinical significance.

Methods:

The authors conducted a retrospective review of 125 consecutive patients with a diagnosis of middle cerebral artery (MCA) aneurysm. Eighty-four patients harboring 100 MCA aneurysms were studied; 41 patients were excluded for lack of adequate imaging or for fusiform morphology of the aneurysm. Demographic characteristics including age, side, sex, subarachnoid hemorrhage, intracerebral hematoma, multiple aneurysms, and type of treatment were obtained.

Results:

The average patient age was 57.3 years (range, 29–79 yr); 69 were women and 15 were men. Fifty-eight were right MCA aneurysms and 42 were left aneurysms. Fourteen patients had multiple MCA aneurysms. Thirty-nine of 100 aneurysms were associated with subarachnoid hemorrhage. Twelve of 100 aneurysms were associated with an intracerebral hematoma. The average aneurysm sizes were 9.1 mm overall (range, 2.0–27.0 mm), 12.3 mm for ruptured aneurysms, and 7.5 mm for unruptured. There were 36 M1 bifurcation aneurysms, 39 early frontal branch aneurysms, 18 early temporal branch aneurysms, four lenticulostriate artery aneurysms, and three trifurcation aneurysms.

Conclusion:

In our retrospective review, the majority of MCA aneurysms arose along the M1 segment proximal to the M1 bifurcation. Early frontal branch aneurysms were more common than typical M1 segment bifurcation aneurysms. M1 segment aneurysms arising from early frontal and early temporal branches have distinct anatomic features that impact surgical management and outcome. Understanding the relationship between the recurrent lenticulostriate arteries arising from the proximal segments of these early branches and the aneurysm neck should allow surgeons to avoid many postoperative ischemic complications when dealing with these challenging lesions.

Aneurysms located at the proximal anterior cerebral artery and anterior communicating artery associated with middle cerebral artery aplasia: case report

BACKGROUND

Aneurysms arising from the proximal anterior cerebral artery (ACA) are quite rare. Here, we report upon such a case of aneurysms located at the proximal ACA and anterior communicating artery associated with middle cerebral artery (MCA) aplasia.

CASE DESCRIPTION

A 64-year-old woman complained of severe headache. Brain computed tomography scans demonstrated acute subarachnoid hemorrhage. Angiograms showed 2 aneurysms located at the anterior communicating artery and proximal ACA, but did not show an MCA shadow on the lesion side. Instead, multiple collateral vessels ran toward the sylvian fissure and supplied the MCA territory, together with hypertrophied perforating branches. The operative findings confirmed that the cordlike rudimentary MCA had no internal blood flow. The 2 aneurysms were secured by neck clipping.

CONCLUSION

The combined effects of these anomalies on the hemodynamic equilibrium of the arteries and the genesis of the aneurysms are noteworthy.

Persistent carotid-vertebral anastomosis associated with contralateral accessory middle cerebral artery

An exceptional case is reported of a complex anomaly of the brain arteries including low left carotid bifurcation, persistent carotid-vertebral anastomosis on the left and accessory middle cerebral artery on the right; the whole posterior circulation was only filled through the anomalous anastomotic vessel which joined with the vertebral artery because of a contralateral hypoplasic vertebral artery and the absence of both posterior communicating arteries. This association has not been previously reported in the literature. The embryological processes leading to these arterial anomalies are discussed. Risks related to a severe carotid stenosis or occlusion and to surgical or endovascular procedures in patients harboring these arterial anomalies are emphasized.

Aneurysms in Twig-Like Middle Cerebral Artery

BACKGROUND

We report a vascular abnormality of the middle cerebral artery (MCA) that has not been described in the literature before.

METHODS

Two patients (1 male and 1 female; age 44 and 67 years, respectively) were found to have a vascular abnormality in which the main trunk of the MCA had a twig-like form. Both patients presented with intracranial hemorrhage.

RESULTS

In these 2 patients, the abnormality was seen before the genu of the MCA. They had an intracranial hemorrhage due to an associated aneurysm inside the twigs. The twig appeared to be a network between the bifurcation of internal carotid artery and insular segment of MCA, and it was different from the collateral circulation due to acquired occlusion or moyamoya disease.

CONCLUSION

This new type of vascular lesion of the MCA is not benign. It appears to be associated with the occurrence of an aneurysm, an important clinical aspect.

Endovascular treatment of an "anterior cerebral artery" aneurysm in a patient with "embryonic unfused middle cerebral artery" anomaly: a case report

We report a unique case of an anterior cerebral artery aneurysm in a patient with embryonic unfused middle cerebral artery anomaly. The arterial twigs of the middle cerebral artery supply the entire middle cerebral artery territory including the lenticulostriate branches. There was a vessel incorporated into the aneurysm, which was referred to as an accessory middle cerebral artery and it gave rise to a lenticulostriate branch. The aneurysm was occluded with detachable coils using a remodeling technique. After successful occlusion of the aneurysm the so-called accessory middle cerebral artery including its lenticulostriate branch started to fill from the anomalous middle cerebral artery network and the patient did not experience any ischemic injury.

Aneurysm rupture at an anomalous collateral artery that extended from the proximal A2segment to the middle of the M1segment, bypassing atresia of the internal carotid artery bifurcation

The authors report the first known case in which an anomalous collateral artery was found to connect the proximal A2 segment with the middle of the M1 segment. This rarity was associated with atresia of the T-shaped internal carotid artery bifurcation. Two aneurysms had developed on a tortuous and tangled portion of the anomalous artery; one of them had ruptured, producing a subarachnoid hemorrhage and an intracerebral hematoma in the area of the putamen. The aneurysms were clipped and the intracerebral hematoma was removed via an emergency craniotomy. Possible causes of the anomaly and the differences between it and accessory and duplicated middle cerebral arteries are reviewed.

Variaciones del sector anterior del polígono de Willis. Correlación anatomo-angiográfica y su implicancia en la cirugía de aneurismas intracraneanos (Arterias: ácigos cerebral anterior, mediana del cuerpo calloso y cerebral media accesoria)

It is worlwide accepted that in almost 60% of cases, anatomical variants in the Circle of Willis can be found. Some of them are associated with vascular malformations such as aneurysms. The knowledge of these anatomical variants is of vital importance when facing surgery, being the aims to preserve arteries in unusual localisations, which when injured can determine invalidating sequelae. The authors have reviewed 192 cerebral hemispheres, finding three variants in the anterior Circle of Willis: Azigos anterior cerebral artery; Median artery of the corpus callosum and accessory middle cerebral artery. The authors make an anatomical description of the findings, their angiographical correlation, and describe the influence of these changes during surgery of aneurysms in the involved regions.

Saccular aneurysm of the accessory middle cerebral artery--case report

A 30-year-old man presented with a rare ruptured saccular aneurysm located at the junction of the accessory middle cerebral artery and the horizontal portion (A1 segment) of the anterior cerebral artery. A right frontotemporal craniotomy was performed and the aneurysm was clipped through a transsylvian approach. The postoperative course was uneventful and he was discharged in good condition. The transsylvian approach is the method of choice for such aneurysm.

The Department of Neurosurgery at Seoul National University: past, present, and future

The Department of Neurosurgery at Seoul National University College of Medicine is one of the oldest neurosurgical departments in Korea, and it is a center of academic leadership in neurosurgery. In September 1957, the department was established by Bo Sung Sim, and it has produced many leaders of neurosurgery in Korea. Chairmen Bo Sung Sim, Kil Soo Choi, Dae Hee Han, and Byung-Kyu Cho each brought special skills and talents to the development of the department. The current and fifth chair, Hyun Jib Kim, assumed the chairmanship in July 2000. The department comprises 11 full-time faculty members, 5 fellows, and 14 residents. More than 1,700 neurosurgical procedures are performed annually in four operating theaters. A gamma knife was installed in 1997, and approximately 200 gamma knife procedures are performed each year. In addition to clinical activities, research and education for graduate and postgraduate students are also particular strengths of the department. This article traces the clinical, academic, and scientific development of the department, its present activities, and its future direction.