Distal anterior cerebral artery aneurysms

Combined endovascular embolization and decompressive craniectomy for microsurgical resection of giant ruptured distal anterior cerebral artery aneurysm

Giant ruptured distal anterior cerebral artery aneurysms are rare, challenging pathologies that may require a combination of microsurgical and endovascular techniques for optimal treatment [1-9]. We describe the case of a female in her 40 s who presented with a Hunt-Hess 4, Fisher 4 subarachnoid hemorrhage from a multiply ruptured, giant distal anterior cerebral artery aneurysm. The patient underwent coil and n-BCA glue embolization of the aneurysm and its feeding A2 anterior cerebral artery. She subsequently underwent decompressive craniectomy, intracerebral hematoma evacuation, and microsurgical trapping and resection of the aneurysm. Postoperative imaging demonstrated no further aneurysm filling, complete hematoma evacuation, and good decompression. The technical considerations and literature for the combined treatment of large and giant ruptured aneurysms are reviewed. The case presentation, operative nuances, and postoperative course with imaging are reviewed with detailed anatomical diagrams to orient the viewer. The patient consented to the procedure and to the publication of her imaging.

Endovascular treatment of distal anterior cerebral artery aneurysms using flow modulation devices: mid- and long-term results from a two-center study

Purpose

Flow-diverter (FD) stents have become an established treatment for intracranial aneurysms in recent years, but their use for aneurysms in distal cerebral vessels with small carrier vessel diameters remains controversial. This study describes the method and mid- and long-term outcomes of FD treatment of distal anterior cerebral artery aneurysms (DACAAs) at two neurointerventional centers, to elucidate this topic and provide more in-depth data.

Methods

Data for all patients at two neurointerventional centers who were treated with FDs for DACAAs in the pericallosal and supracallosal segment of the anterior cerebral artery were retrospectively analyzed. Data on periprocedural complications, and short-, mid- and long-term follow-up findings were recorded.

Results

Forty-one patients were eligible for inclusion in the study. Three FD models were used, one of which had an anti-thrombotic coating. Two periprocedural complications (5%) occurred but did not cause a change in the mRS. In the long-term follow-up, at 29 months and beyond, 83% of assessable patients showed complete occlusion of the aneurysms without new neurological deficits.

Conclusion

FDs are a safe and effective treatment approach for DACAAs. This study indicated a low risk of complications, and high closure rates in short-, mid- and long-term follow-up.

An analytical method informed by clinical imaging data for estimating outlet boundary conditions in computational fluid dynamics analysis of carotid artery blood flow

Stroke occur mainly due to arterial thrombosis and rupture of cerebral blood vessels. Previous studies showed that blood flow-induced wall shear stress is an essential bio marker for estimating atherogenesis. It is a common practice to use computational fluid dynamics (CFD) simulations to calculate wall shear stress and to quantify blood flow. Reliability of predicted CFD results greatly depends on the accuracy of applied boundary conditions. Previously, the boundary conditions were estimated by varying values so that they matched the clinical data. It is applicable upon the availability of clinical data. Meanwhile, in most cases all that can be accessed are arterial geometry and inflow rate. Consequently, there is a need to devise a tool to estimate boundary values such as resistance and compliance of arteries. This study proposes an analytical framework to estimate the boundary conditions for a carotid artery based on the geometries of the downstream arteries available from clinical images.

Mini anterior interhemispheric approach for A3 segment distal anterior cerebral artery aneurysms

INTRODUCTION

Aneurysms of the A3 segment of the distal anterior cerebral artery (DACA), in relation to the genu of the corpus callosum, are specific sub-group which pose unique surgical challenges due to their discrete anatomical location. We describe a mini-anterior interhemispheric approach which can be safely utilised to clip these aneurysms rather than the traditional bifrontal approach.

METHODS

Retrospective analysis of the clinical and radiological data of ruptured DACA-A3 aneurysms operated between 2014 and 2021 at our institute. A curvilinear scalp incision within the hairline followed by raising small, unilateral, free frontal bone flap, avoiding the opening of frontal sinus. Superior sagittal sinus is displaced medially, inter-hemispheric dissection carried out with posterior trajectory and small callosotomy is performed. DACA is skeletonised, proximal control is established, and the A3 aneurysm is dissected and clipped.

RESULT

Our cohort of 18 patients had a definite female preponderance (F:M::2:1) with mean age of 55.6 years. On admission three patients were categorized as WFNS Grade I, thirteen in Grade II, and two in Grade III for subarachnoid haemorrhage. All the patients had evidence of blood in the interhemispheric fissure; intraparenchymal haemorrhage was seen in seven, with intraventricular haemorrhage in six patients. Within the A3 segment six aneurysms were infragenu (inferior), eight were at the genu (anterior) and four were supragenu (superior). Two (11.1%) elderly patients succumbed post-surgery following ischemic infarcts and associated complications. At the time of follow-up at 3 months of the remaining sixteen (72.2%) patients, thirteen had a good outcome (mRS 0-3) and three (16.7%) had a poor outcome (mRS > 3).

CONCLUSION

The mini anterior interhemispheric is an effective minimally invasive alternative for A3 segments aneurysms and helps to avoid the complications of the conventional bifrontal interhemispheric approach.

A complete thrombotic large aneurysm at the nonbranching segment of the distal anterior cerebral artery mimicking a cavernous malformation: illustrative case

BACKGROUND

Thrombotic aneurysms at the nonbranching segment of the distal anterior cerebral artery (ACA) are extremely rare and difficult to differentiate from cavernous malformations by radiographic features alone.

OBSERVATIONS

Computed tomography and magnetic resonance imaging of a 30-year-old female patient with a chronic headache complaint revealed a 22-mm frontal lobe mass. The mass showed heterogeneous mixed intensity and hemosiderin deposits on magnetic resonance images. It was not visualized by conventional angiography, indicating that the mass and ACA/other vessels were not connected. The patient was preoperatively diagnosed with a cavernous malformation. However, during resection, the mass surface was white and smooth, different from a cavernous malformation. Although the mass was adherent to the pericallosal artery branch, no luminal continuity was observed. After detachment, the mass was completely resected. Pathological and immunohistochemical findings indicated a vessel wall and interior thrombus. The patient was rediagnosed with a thrombotic aneurysm at the distal ACA nonbranching segment and discharged 10 days postsurgery without neurological deficits.

LESSONS

Because radiographic findings of thrombotic aneurysm and cavernous malformation are similar, mass lesions in contact with major arteries should be differentiated as thrombotic aneurysms, even when the artery lumen appears disconnected from the mass.

Natural history and management of posterior cerebral artery aneurysms: a systematic review and meta-analysis of individual patient data

We conducted a comprehensive review and meta-analysis to investigate clinical, radiographic characteristics, and treatment outcomes of posterior cerebral artery aneurysms (PCAA). We systematically reviewed English-language articles investigating available treatments (parent artery occlusion (PAO), microsurgery, reconstructive endovascular (rEVT), and conservative treatments) for PCAA and analyzed the based on aneurysm morphology and rupture status. Six-hundred-eighty-five patients with 698 PCAA were identified from 59 studies. Overall, 371 (54.2%) aneurysms were ruptured, 325 (49%) were saccular, and 342 (51%) were non-saccular aneurysms. The mean age of the saccular was lower (40 years) than non-saccular aneurysm group (50 years) (P < .05). In ruptured PCAA, favorable clinical outcomes were comparable between the treatment groups except for patients treated conservatively, which had lower rates of favorable clinical outcomes (35.6%) and higher mortality (55.7%) (P < .0001). Ruptured aneurysms treated with rEVT (22.6%) had the highest recanalization rates compared to PAO (9.2%, P = 0.0001) and microsurgery (3.8%, P = 0.005). In unruptured PCAA, clinical outcomes were similar; higher complication rates were noted in microsurgery (40.4%, P = 0.026) and PAO (21.5%, P = 0.015) compared to rEVT (13.2%), which had higher recanalization rates (15.6%, P < .0001). The rates of subsequent stroke following PAO were 21.8% for unruptured and 32.3% for ruptured PCAA (P = 0.078). Ruptured PCAA portend worse prognosis and typically require an intervention to achieve better outcome whereas the benefit of an intervention in unruptured PCAA is much less clear. rEVT is promising for PCAA management with a good clinical and safety profile but more recurrence compared to PAO and microsurgery.

Contralateral transradial access for coil embolization of distal anterior cerebral artery aneurysm associated with a steep ipsilateral A1-A2 angle

OBJECTIVE

Endovascular treatment of distal anterior cerebral artery aneurysms is commonly addressed via the ipsilateral A1 segment of the anterior cerebral artery. However, when the parent pericallosal artery has a sharp ipsilateral A1-A2 angle, catheterization through the ipsilateral A1 segment can potentially result in vessel injury, catheter kinking, and/or compromised/stagnant anterior cerebral artery flow. Here, we present a case of a distal anterior cerebral artery aneurysm associated with a steep ipsilateral A1-A2 angle treated with contralateral transradial coil embolization.

CASE PRESENTATION

A 91-year-old woman presented with a ruptured left distal anterior cerebral artery aneurysm at the A3 segment. The parent pericallosal artery had a steep ipsilateral A1-A2 angle. To safely achieve coil embolization of the aneurysm, a contralateral transradial system via the right A1 segment was employed. Although a secondary ipsilateral transradial system was required for contrast injection, aneurysm obliteration was successfully achieved without vessel injury or system instability.

CONCLUSION

The A1-A2 angle can be a key anatomical factor in the endovascular treatment of distal anterior cerebral artery aneurysms. The contralateral transradial system is a useful treatment option for distal anterior cerebral artery aneurysms associated with sharp ipsilateral A1-A2 angles. However, if the distal anterior cerebral artery aneurysm cannot be clearly visualized through the contralateral system, an ipsilateral system will be required for contrast injection.

A Simple Method to Estimate the Trajectory to the Genu of the Corpus Callosum in the Interhemispheric Approach for Distal Anterior Cerebral Artery Aneurysms

In the interhemispheric approach (IHA) for the distal anterior cerebral artery (DACA) aneurysms, the surgical trajectory to a DACA aneurysm is very important because surgeons sometimes encounter the intraoperative disorientation and the premature rupture. The purpose of this study was to clarify the anatomical landmarks indicating the trajectory to the genu of the corpus callosum (GCC) at the early stage of dissection for the correct intraoperative orientation. “Point A” was defined as the crossing point between the frontal bone and the line connecting the projected external acoustic opening (EAO) and the GCC on the midline slice of the sagittal three-dimensional computed tomography angiography (3D-CTA) images. We measured the distance from the nasion to Point A using midline sagittal slice images from 50 patients who underwent 3D-CTA at our institution. The average distance was 7.0 cm (±0.3 cm). Therefore, the direction of the spatula inserted in the direction of the EAO from Point A (7 cm above the nasion) corresponds to the trajectory to the GCC. In DACA aneurysms of the A3 segment, the pericallosal artery distal to the aneurysm can be safely identified by dissecting the interhemispheric fissure distal to the trajectory to the GCC. In DACA aneurysms of the A4 or A5 segment, the parent artery of the aneurysm can be safely identified by dissection along the trajectory to the GCC. Point A and the EAO can be used as landmarks indicating the trajectory to the GCC for the correct intraoperative orientation in the IHA for DACA aneurysms.

Current treatment options and prognostic factors for ruptured distal anterior cerebral artery aneurysms

Background:

Distal anterior cerebral artery (ACA) aneurysms are rare, representing 1–9% of all intracranial aneurysms. The best treatment strategy for these aneurysms continues to be debated. We clarified the clinical features and treatment outcomes of patients with ruptured distal ACA aneurysms according to the treatment options at our institute.

Methods:

Thirty-seven consecutive patients (26 women; mean age, 65.2 years) with ruptured distal ACA aneurysms who underwent surgical clipping or coil embolization between 2012 and 2018 were included in the study. Clinical presentations, radiographic findings, and outcomes were retrospectively reviewed and compared between patients who underwent either surgical clipping or coil embolization. Risk factors associated with poor outcomes (modified Rankin Scale 4–6) were analyzed using multiple regression analysis.

Results:

Nineteen patients (51.4%) had World Federation Neurological Surgeons (WFNS) Grade IV-V, 18 (48.7%) had frontal lobe hematomas, and 13 (35.1%) had multiple aneurysms. Surgical clipping and endovascular coiling were performed in 28 (75.7%) and nine (24.3%) patients, respectively. Aneurysms located at the A4-5 portions were mainly treated by surgical clipping (P = 0.04). There were no significant between-group differences in procedure-related morbidity and mortality; however, the complete occlusion rate was higher in the surgical group (P < 0.01). Overall, a favorable neurological outcome at discharge (mRS 0–3) was obtained in 23 patients (62.5%). Multiple regression analysis revealed that WFNS Grade IV-V and frontal lobe hematomas were risk factors for poor outcomes (mRS 4–6).

Conclusion:

Acceptable outcomes were obtained in 62.5% of cases, and there were no significant between-group differences in treatment results between clipping and coiling. A poor WFNS grade and intracerebral hematomas were risk factors for a poor prognosis.

Therapy results of pericallosal aneurysms: A retrospective unicenter study

This retrospective study aims to compare treatment results of ruptured and unruptured pericallosal artery aneurysms (PAAs) regarding patient outcome and aneurysm recurrence after endovascular treatment (EVT) and neurosurgical treatment (NT). A total of 67 patients with PAA were admitted to our hospital, 44 patients with subarachnoidal hemorrhage (SAH) due to a ruptured PAA and 23 patients with unruptured PAA. The radiographic features of PAA were collected from pre-treatment digital subtraction angiography. In addition, demographic, clinical and radiographic parameters of all patients were recorded. Outcome was measured based on the modified Rankin scale (mRS) at 6 months after admission (favorable mRS score, 0-2 vs unfavorable mRS score, 3-6). Overall 46 patients underwent EVT and 21 patients NT. Six months after discharge 24 patients with SAH had a favorable outcome (mRS 0-2) and 16 patients an unfavorable outcome (mRS 3-6). Mortality rate of patients with SAH was 9.1% (4/44). Overall aneurysm recurrence was treated in 13 % of patients in the EVT cohort (6/46), whereas patients treated with NT had no recurrence. All patients with unruptured PAA had a favorable outcome. EVT and NT of PAA show comparable good results, although aneurysm recurrence occurs more often after EVT.

Wedge Resection of the Falx to Clip a Distal Anterior Cerebral Artery Aneurysm

BACKGROUND

The unilateral anterior interhemispheric approach has been widely used for distal anterior cerebral artery (DACA) aneurysms. However, there are some drawbacks of this approach because of the narrow operative field, including possible brain traction injury, bridging vein injury, and inadequate exposure of the aneurysm. Here, we report a case of a DACA aneurysm covered by the falx that could not be totally exposed with the unilateral interhemispheric approach. We successfully obtained a wide view with wedge resection of the falx, avoiding excessive brain traction and division of the superior sagittal sinus.

CASE DESCRIPTION

A 76-year-old woman with a 6-mm unruptured DACA aneurysm underwent a unilateral craniotomy with the anterior interhemispheric approach. In the operative field, the aneurysm was found at the midline, just below the falx. The aneurysm was covered by the falx and could not be completely exposed with the usual brain retraction. Therefore, we performed wedge resection of the falx, thus obtaining sufficient surgical field and totally exposing the aneurysm. We were then able to apply the clip successfully. Postoperative brain computed tomography angiography showed no remnant aneurysm sac or complications of falx resection or brain retraction, such as bleeding or vessel injury.

CONCLUSIONS

When an aneurysm is located just below the falx and is exposed inadequately, performing wedge resection of the falx can expose the aneurysms adequately for application of the clip.

Parent Artery Occlusion for Treatment of a Traumatic Pericallosal Artery Aneurysm: Case Report and Review of the Literature

BACKGROUND

Traumatic intracranial aneurysms are rare complications after head trauma. This report describes the case of a patient with a traumatic pericallosal aneurysm.

CASE DESCRIPTION

A 73-year-old man developed headache and lower limb paresis, and emergency computed tomography scan revealed a hematoma in the corpus callosum. We performed coil embolization for a pericallosal aneurysm, but follow-up angiography showed recurrence of the aneurysm 6 days after the surgery. We diagnosed this as a traumatic aneurysm and subsequently performed parent artery occlusion without any complications.

CONCLUSIONS

We performed parent artery occlusion for a traumatic aneurysm of the pericallosal artery without complications. Pericallosal aneurysms are rare, but we must consider them when encountering a delayed hematoma around the corpus callosum.

Coiling for an unruptured saccular aneurysm at the non-branching segment of the distal anterior cerebral artery: Case report and literature review

BACKGROUND

Saccular aneurysms in the non-branching segment of the distal anterior cerebral artery (DACA) are extremely rare. Here, we describe the first case of coil embolization using a simple, non-adjunctive technique for an aneurysm at this rare location.

CASE DESCRIPTION

A 74-year-old man with an asymptomatic, unruptured aneurysm of the right DACA was followed up annually for 3 years by medical checkup. Endovascular treatment was proposed because of a slight angiographic change in the shape of the aneurysm in the past year. The aneurysm at the non-branching site of the right calloso-marginal artery was 2 mm distal to the origin, and measured 3 mm in height and 3.3 mm in width, with a neck measuring 1.7 mm wide; the calloso-marginal artery diameter was 1.6 mm. The aneurysm was successfully embolized with a simple technique using a Pre-Shaped S Microcatheter and two coils.

CONCLUSIONS

The simple, non-adjunctive technique for coil embolization of saccular side-wall type aneurysm in the non-branching segment of the DACA could be performed using the appropriate catheter and a softer coil.

[Giant thrombosed aneurysm of the pericallosal artery: clinical observation, literature review]

Are characterized by Distal giant aneurysms of the anterior cerebral artery are an extremely rare pathology. There are less than 40 cases of this disease described in literature.

OBJECTIVE

The aim of the article is to present the clinical observation of a successfully treated giant aneurysm of the pericallosal artery in a 58-year-old man, and also analyze the publications on distal cerebral aneurysms.

MATERIAL AND METHODS

The data of a patient hospitalized with a suspected tumor of the left brain hemisphere spreading to the left lateral ventricle is presented. Repeated MRI suggests a giant subtotal thrombotic aneurysm of the left perical artery, which was confirmed by SCT angiography. The patient underwent aneurysm treping-cliping with dissection of the aneurysm sac. In the analysis of the literature it was shown that the frequency of perical artery aneurysms varies from 5.3-6.0%, and giant aneurysms of this localization are extremely rare and occur in 1-4.5% of all perical artery aneurysms. Unlike distal anterior cerebral artery aneurysms of small and medium size, giant aneurysms are characterized by pseudotumorrhagic symptoms, which causes diagnostic difficulties.

CONCLUSION

It is necessary to remember about the diagnostic difficulties caused by the pseudotumorrhosis of the giant aneurysms of the pericallosal artery and the frequent negative angiography data due to total thrombosis of the aneurysmal sac. The gold standard is microsurgical clipping with excision of the aneurysmal sac. The prognosis for this group of patients is favorable.

Mirror Distal Anterior Cerebral Artery Aneurysms in a Patient with Subarachnoid Hemorrhage

BACKGROUND

Mirror distal anterior cerebral artery aneurysms (DACAAs) are a rare finding in patients with subarachnoid hemorrhage, with only a few cases reported.

CASE DESCRIPTION

A 40-year-old man was admitted for sudden-onset headache, nausea and vomiting, and transient right arm hypoesthesia. Computed tomography scan showed a subarachnoid hemorrhage with intracerebral hemorrhage within the interhemispheric fissure, but computed tomography angiography failed to identify any aneurysms. Subsequent digital subtraction angiography with three-dimensional reconstructions revealed 1.5-mm-diameter mirror DACAAs on the A3 segments. However, the definite rupture site remained unidentifiable. After interdisciplinary consultation, endovascular treatment was favored, and complete occlusion of both DACAAs was achieved by coiling without stent placement. During coiling of the right DACAA, a thrombus in the right callosomarginal artery formed, and treatment with abciximab (ReoPro) was initiated to dissolve the thrombus. After treatment, the patient presented with right leg paresis; however, computed tomography did not show any ischemia, intracerebral hemorrhage increase, or vasospasm. Over the following days, the leg paresis improved, and the patient achieved increased mobilization. He was transferred for further rehabilitation 16 days after hemorrhage. The leg paresis had recovered to a grade 3/5.

CONCLUSIONS

Rapid identification of the rupture site in patients with subarachnoid hemorrhage and multiple aneurysms is crucial for initiating optimal treatment. In patients with mirror aneurysms in close proximity to each other, this is not easily accomplished, complicating treatment decisions. Although clipping has been the standard for DACAA occlusion, coiling should be taken into consideration as a viable alternative.

[Proximal clipping of a large fusiform aneurysm of the A2 segment of the left anterior cerebral artery with awakening of the patient (a case report and literature review)]

Arterial aneurysms of the A2 segment are very rare (<1%) peripheral aneurysms of the anterior cerebral artery (ACA) territory. Usually, these are saccular aneurysms; there are single reports of fusiform aneurysms of this location. Surgical treatment of these aneurysms involves both microsurgical and endovascular interventions. In the presented case, we used deconstructive surgery (proximal clipping of the aneurysm) with intraoperative awakening of the patient, which verified sufficient collateral blood flow. In the case of focal deficit development, we planned to simultaneously perform an interarterial anastomosis between the A3 segments of the right and left ACAs.

Operative Management of Distal Anterior Cerebral Artery Aneurysms Through a Mini Anterior Interhemispheric Approach

BACKGROUND

Distal anterior cerebral artery (DACA) aneurysms, also known as pericallosal artery aneurysms, are present in 1.5%-9% of all intracranial aneurysms. Here we characterize the important microsurgical anatomy of DACAs; describe the surgical approach to treating these aneurysms with a minimally invasive surgical technique, the mini anterior interhemispheric approach (MAIA); and examine the nuances of aneurysm clipping in this region.

METHODS

This was a retrospective and descriptive analysis of a series of aneurysm surgeries performed at the National Institute of Neurology and Neurosurgery in Mexico City. Cadaveric dissections were used to demonstrate relevant cerebrovascular anatomy. We analyzed patient demographic data and aneurysm characteristics. Patients' neurologic grade was evaluated using the Hunt and Kosnik (H-K) scale, and surgical outcomes were evaluated using the Glasgow Outcome Scale (GOS). Other variables were analyzed using the χ² test.

RESULTS

We analyzed a total of 32 DACA aneurysms (10 nonruptured and 22 ruptured), representing 5.8% of all aneurysms. The study cohort was 64.3% females and 35.7% males. H-K grade II was the most frequent classification (32.4%); 42.8% of patients presented with a Fisher grade IV aneurysm. Aneurysm location was classified as supra-genu, genu, or infra-genu. Eight patients had multiple aneurysms, among which 50% were located at the bifurcation of the middle cerebral artery.

CONCLUSIONS

Surgical clipping through a MAIA approach is an excellent treatment option for pericallosal artery aneurysms.

Three distal anterior cerebral artery aneurysms in the same branch associated with five additional intracranial aneurysms

Background:

Multiple distal anterior cerebral artery (DACA) aneurysms appear as rare findings. Simultaneous treatment of such lesions can be particularly challenging. A report of three aneurysms on the same parent artery has not been reported before. We report a case of three DACA aneurysms treated within one microsurgical operation in a patient with eight aneurysms.

Case Description:

A 62-year-old woman incidentally presented with multiple various size saccular aneurysms, including tree on the left DACA. One of the DACA aneurysm was located on the A3 segment, and the other two were on the A4 and A5 segments. Ligation of all three of these aneurysms was planned in one operation. A standard anterior interhemispheric approach was utilized. Three aneurysms were successfully clipped using four clips. Intraoperative angiography confirmed aneurysm occlusion with parent artery patency preservation. The patient showed no new postoperative neurological deficit.

Conclusion:

Clipping multiple DACA aneurysms within a single microneurosurgical operation is a feasible treatment option. Meticulous analysis of preoperative imaging features is crucial for selecting the best, patient-specific treatment strategy.

Single center experience and technical nuances in the treatment of distal anterior cerebral artery aneurysms

Objective: This study presents the experience of one neurosurgical center in the treatment of 18 consecutive patients with distal anterior cerebral artery (DACA) aneurysms during a 10 years period. Our aim was to compare treatment outcomes of these lesions with intracranial aneurysms in general, and to present technical nuances in surgical treatment.

Methods: We analyzed the clinical and radiological data of 18 patients treated between 2005 and 2015. All patients were treated surgically using the microscope. No patients were lost to follow-up. We compared treatment and outcome of ruptured DACA aneurysms (n 18) with all consecutive ruptured aneurysms treated in our clinic during the same period (n 446).

Results: DACA aneurysms accounted for 4% of all intracranial aneurysms. They were smaller (median, 5,5 versus 9 mm) We found only one case with associated aneurysms (5,5%). DACA aneurysms presented more often with intracerebral hematomas (39% versus 26%) than ruptured aneurysms in general. Their microsurgical treatment showed the same complication rates (treatment morbidity, 15%) as for other ruptured aneurysms in literature. Their mortality rate was lower (11% versus 24%).

Conclusion: Despite their specific anatomic features, and particular surgical technique, with modern treatment methods, ruptured DACA aneurysms have the same favorable outcome and lower mortality as ruptured aneurysms in general.

Pterional or Subfrontal Access for Proximal Vascular Control in Anterior Interhemispheric Approach for Ruptured Pericallosal Artery Aneurysms at Risk of Premature Rupture

OBJECTIVE

Cases of a ruptured pericallosal artery aneurysm with a high risk of intraoperative premature rupture and technical difficulties for proximal vascular control require a technique for the early and safe establishment of proximal vascular control.

METHODS

A combined pterional or subfrontal approach exposes the bilateral A1 segments or the origin of the ipsilateral A2 segment of the anterior cerebral artery (ACA) for proximal vascular control. Proximal control far from the ruptured aneurysm facilitates tentative clipping of the rupture point of the aneurysm without a catastrophic premature rupture. The proximal control is then switched to the pericallosal artery just proximal to the aneurysm and its intermittent clipping facilitates complete aneurysm dissection and neck clipping.

RESULTS

Three such cases are reported: a ruptured pericallosal artery aneurysm with a contained leak of the contrast from the proximal side of the aneurysm, a low-lying ruptured pericallosal artery aneurysm with irregularities on its proximal wall, and a multilobulated ruptured pericallosal artery aneurysm with the parasagittal bridging veins hindering surgical access to the proximal parent artery. In each case, the proposed combined pterional-interhemispheric or subfrontal-interhemispheric approach was successfully performed to establish proximal vascular control far from the ruptured aneurysm and facilitated aneurysm clipping via the interhemispheric approach.

CONCLUSION

When using an anterior interhemispheric approach for a ruptured pericallosal artery aneurysm with a high risk of premature rupture, a pterional or subfrontal approach can be combined to establish early proximal vascular control at the bilateral A1 segments or the origin of the A2 segment.

A5 segment aneurysm of the anterior cerebral artery, imbedded into the body of the corpus callosum: A case report

BACKGROUND

The A5 segment aneurysms of the anterior cerebral artery are rare, approximately 0.5% of all intracranial aneurysms. They are small with a wide base located in the midline, with the domes mostly projecting upward or backward.

CASE DESCRIPTION

The authors describe a unique case of A5 segment aneurysm, with the dome embedded into the body of the corpus callosum. This 41-year-old female was admitted to the neurology department for possible multiple sclerosis investigation. Computed tomography angiogram (CTA) revealed a 4-mm right-sided pericallosal artery aneurysm, with rare configuration, which was caudally projected, embedded into the body of the corpus callosum. Considering the family history, patient underwent a prophylactic ligation surgery. The postoperative CT and CTA showed no complication and successful occlusion of the aneurysm with no ischemia or hemorrhage in the corpus callosum.

CONCLUSION

To the best of our knowledge, this is the first case of an aneurysm with this configuration. Our rare case of A5 segment aneurysm demonstrates the importance of planning of the surgery, choosing the appropriate approach, and knowing the detailed anatomy of the region, as well as the necessity of microsurgical clipping of small unruptured AdistAs.

Safety and Efficacy of Surgical and Endovascular Treatment for Distal Anterior Cerebral Artery Aneurysms: A Systematic Review and Meta-Analysis

BACKGROUND

Aneurysms of the distal anterior cerebral artery (DACA) are rare, representing between 1% and 9% of all intracranial aneurysms. The best treatment strategy for these aneurysms continues to be debated.

OBJECTIVE

We conducted a systematic review of the literature to evaluate the safety and efficacy of treatment strategies of DACA aneurysms.

METHODS

A systematic search of Medline, Embase, Scopus, and Web of Science was performed for studies published from January 2000 to August 2015. We included studies describing treatment of DACA aneurysms with ≥10 patients. Random effects meta-analysis was used to pool the following outcomes: complete occlusion, technical success, periprocedural morbidity/mortality and stroke rates, aneurysm recurrence/rebleed, and long-term neurologic morbidity/mortality.

RESULTS

Thirty studies with 1329 DACA aneurysms were included. Complete occlusion was 95% (95% confidence interval [CI], 91.0%-97.0%) in the surgical group and 68% (95% CI, 56.0%-78.0%) in the endovascular group (P < 0.0001). Aneurysm recurrence occurred in 3% (95% CI, 2.0%-4.0%) after surgery and in 19.1% (95% CI, 12.0%-27.0%) after endovascular treatment (P < 0.0001). Overall neurologic morbidity and mortality were 15% (95% CI, 11.0%-21.0%) and 9% (95% CI, 7.0%-11.0%) after surgery and 14% (95% CI, 10.0%-19.0%) (P = 0.725) and 7% (95% CI, 5.0%-10.0%) (P = 0.422) after endovascular treatment, respectively. Overall long-term favorable neurologic outcome was 80% and it was equal in both groups (80%; 95% CI, 73.0%-85.0% in the surgical group and 80%; 95% CI, 72.0%-87.0% in the endovascular group) (P = 0.892).

CONCLUSIONS

Our meta-analysis showed that both treatment modalities are technically feasible and effective with sufficient long-term aneurysm occlusion and acceptable recurrence/rebleed rates. Surgical treatment is associated with superior angiographic outcomes. There were no substantial differences in procedure-related morbidity and mortality. These findings are important because they suggest that therapy of DACA aneurysms should be performed on a selective, case-by-case basis to maximize patient benefits.

Use of flow diverters in the treatment of unruptured saccular aneurysms of the anterior cerebral artery

BACKGROUND

Few publications have dealt exclusively with the use of flow diverter stents for the treatment of aneurysms of the anterior cerebral artery (ACA).

OBJECTIVE

To determine the efficacy of flow-diverting stents in the treatment of small, unruptured aneurysms of the ACA.

METHODS

We retrospectively reviewed our database of prospectively collected information for all patients treated with flow diversion for an unruptured saccular aneurysm of the ACA between September 2009 and July 2016. The aneurysm fundus size, neck size, number and type of flow-diverting stent (FDS), complications, and follow-up data were recorded.

RESULTS

In total 26 patients, with 27 aneurysms were identified that matched our inclusion criteria (11 male and 15 female). The average age of the patients was 59.3 years (range 27-77 years). All patients, except one, had a single aneurysm affecting the ACA. Fourteen aneurysms were located on the left (51.9%). The average aneurysm fundus size was 2.9 mm (range 2-6 mm). Twenty patients had follow-up angiographic studies. In total, 16 aneurysms were completely excluded, 1 aneurysm showed a very small remnant, and no follow-up angiographic data are available for the remaining patients. One patient had a treatment-related complication.

CONCLUSIONS

Treatment of aneurysms arising from the ACA with flow diverters is technically feasible and carries a high degree of success with low complication rate.

Pseudoaneurysm Formation after Repetitive Suction Thrombectomy Using a Penumbra Suction Catheter

With the recent advent of suction catheters, the use of manual aspiration thrombectomy (MAT) for patients with acute ischemic stroke with large vessel occlusion has increased. Although contrast leakage and subarachnoid hemorrhage have been reported during MAT procedures, pseudoaneurysm formation due to vessel injury by suction catheters has not been. We discuss the case of a 60-year-old woman who presented to our emergency room with dysarthria and left-sided weakness. She underwent suction thrombectomy 5 times for acute middle cerebral artery occlusion and significant contrast leakage occurred during the procedure. On follow-up angiogram on post-operative day 15, we noticed a pseudoaneurysm, which was treated with detachable coil embolization. Surgeons who perform suction thrombectomy should keep in mind the possibility of vessel injury that results in the formation of a pseudoaneurysm, especially at the branching site or tortuous segments.

Endovascular treatment of frontopolar artery aneurysm

Traumatic intracranial aneurysms are rare and usually present with subarachnoid hemorrhage, intracranial hemorrhage, subdural hematoma, or intraventricular hemorrhage. These are usually not true aneurysms; hence treatment of these cases poses a therapeutic challenge. In this case report, we describe a young Asian male who presented with a ruptured pseudoaneurysm of the distal branch of the anterior cerebral artery. It was treated successfully with endovascular embolization. To our knowledge, there are few reports of this entity in the literature.

De novo giant A2 aneurysm following anterior communicating artery occlusion

BACKGROUND

De novo intracranial aneurysms are reported to occur with varying incidence after intracranial aneurysm treatment. They are purported to be observed, however, with increased incidence after Hunterian ligation; particularly in cases of carotid artery occlusion for giant or complex aneurysms deemed unclippable.

CASE DESCRIPTION

We report a case of right-sided de novo giant A2 aneurysm 6 years after an anterior communicating artery (ACoA) aneurysm clipping. We believe this de novo aneurysm developed in part due to patient-specific risk factors but also a significant change in cerebral hemodynamics. The ACoA became occluded after surgery that likely altered the cerebral hemodynamics and contributed to the de novo aneurysm. We believe this to be the first reported case of a giant de novo aneurysm in this location. Following parent vessel occlusion (mostly of the carotid artery), there are no reports of any de novo aneurysms in the pericallosal arteries let alone a giant one. The patient had a dominant right A1 and the sudden increase in A2 blood flow likely resulted in increased wall shear stress, particularly in the medial wall of the A2 where the aneurysm occurred 2 mm distal to the A1-2 junction.

CONCLUSION

ACoA preservation is a key element of aneurysm surgery in this location. Suspected occlusion of this vessel may warrant closer radiographic follow-up in patients with other risk factors for aneurysm development.

Endovascular Treatment of Ruptured Pericallosal Artery Aneurysms

Objective

Aneurysms arising from the pericallosal artery (PA) are uncommon and challenging to treat. The aim of this study was to report our experiences of the endovascular treatment of ruptured PA aneurysms.

Methods

From September 2003 to December 2013, 30 ruptured PA aneurysms in 30 patients were treated at our institution via an endovascular approach. Procedural data, clinical and angiographic results were retrospectively reviewed.

Results

Regarding immediate angiographic control, complete occlusion was achieved in 21 (70.0%) patients and near-complete occlusion in 9 (30.0%). Eight procedure-related complications occurred, including intraprocedural rupture and early rebleeding in three each, and thromboembolic event in two. At last follow-up, 18 patients were independent with a modified Rankin Scale (mRS) score of 0-2, and the other 12 were either dependent or had expired (mRS score, 3-6). Adjacent hematoma was found to be associated with an increased risk of poor clinical outcome. Seventeen of 23 surviving patients underwent follow-up conventional angiography (mean, 16.5 months). Results showed stable occlusion in 14 (82.4%), minor recanalization in two (11.8%), and major recanalization, which required recoiling, in one (5.9%).

Conclusion

Our experiences demonstrate that endovascular treatment for a ruptured PA aneurysms is both feasible and effective. However, periprocedural rebleedings were found to occur far more often (20.0%) than is generally suspected and to be associated with preoperative contrast retention. Analysis showed existing adjacent hematoma is predictive of a poor clinical outcome.

Characteristics of Posterior Cerebral Artery Aneurysms

BACKGROUND:

Posterior cerebral artery (PCA) aneurysms are rare lesions. Because of their low incidence, the individual or institutional experience is usually limited.

OBJECTIVE:

To identify specific anatomic features related to PCA aneurysms based on the analyses of pretreatment angiograms.

METHODS:

We performed a detailed angiographic study of 81 patients with a diagnosis of 93 PCA aneurysms. Fifty-three patients underwent computed tomography angiography, 49 underwent digital subtraction angiography, and 6 underwent magnetic resonance angiography. Between 1980 and 2012, a total of 120 patients with 136 PCA aneurysms and 11 352 patients with 16 444 intracranial aneurysms were treated at our institutions.

RESULTS:

There were 29 ruptured and 64 unruptured PCA aneurysms. The distribution of the aneurysms along the PCA segments was P1 (n = 39; 9 ruptured), P1/P2 junction (n = 25; 9 ruptured), P2 (n = 21; 5 ruptured), and P3 (n = 8; 6 ruptured). The median aneurysm size was 7 mm for the ruptured and 4 mm for the unruptured aneurysms. Saccular aneurysms (n = 69, 74%) had a typical projection for each location: P1 segment, upward (67%); P1/P2 junction, anterior/upward (80%); P2 segment, lateral (67%); and P3 segment, posterior (50%). Multiple aneurysms were seen in 43 patients. PCA aneurysms related to arteriovenous malformations were observed in 10 patients.

CONCLUSION:

PCA aneurysms are infrequent lesions, often associated with multiple aneurysms and arteriovenous malformations and are fusiform in shape. Most ruptured PCA aneurysms are smaller than 10 mm and usually distally located. At each PCA segment, saccular PCA aneurysms have a typical dome orientation.

Feasibility and efficacy of endovascular therapy for ruptured distal anterior cerebral artery aneurysms

Surgical clipping has been the primary treatment option for ruptured distal anterior cerebral artery (DACA) aneurysms. Therefore, the literature on endovascular therapy is sparse. The present study investigated the feasibility and efficacy of endovascular therapy for ruptured DACA aneurysms in 31 patients, 26 females and 5 males (mean age 63.2 ± 12.6 years). Mean aneurysm size and neck width were 4.8 ± 2.3 mm and 2.2 ± 0.7 mm, respectively. The Hunt and Hess (H/H) grades just prior to the treatment were scored as H/H grades 1-3 in 20 patients and H/H grades 4-5 in 11 patients. Fifteen patients had an intraparenchymal hematoma (IPH) surrounding the ruptured aneurysm on the initial computed tomography. Overall, 22 patients had a modified Rankin scale (mRS) score of 0-2 and 9 had a mRS score of 3-6 at discharge. H/H grade was closely related to the clinical outcomes, whereas the presence of IPH was not. Overall immediate angiographic outcomes were complete occlusion in 15, residual neck in 11, and residual aneurysm in 5. The overall recurrence rate was 35.3%. Complications including posttreatment rebleeding occurred in 5 patients. Symptomatic vasospasm occurred in 1 of the 18 patients with H/H grades 1-3. Endovascular therapy of ruptured DACA aneurysms is feasible and effective. However, the risks of recurrence and posttreatment bleeding remain to be resolved.

Endovascular treatment of distal anterior cerebral artery aneurysms: single-center experience and a systematic review

In this study, a single center's experience of 20 patients and a systematic review and a meta-analysis of 16 studies, including 279 patients/aneurysms, assessed the safety and efficacy of endovascular treatment of distal anterior cerebral artery aneurysms. The authors conclude that endovascular treatment of distal anterior cerebral artery aneurysms is associated with high angiographic occlusion rates, but the complication rates are higher compared with other aneurysms in the circle of Willis.

Endovascular management of distal ACA aneurysms: single-institution clinical experience in 22 consecutive patients and literature review

BACKGROUND AND PURPOSE

Distal ACA aneurysms remain difficult to treat with endovascular therapy, but improved technology and experience allows for the treatment of some of these aneurysms with excellent results. The purpose of this study was to assess the status of endovascular treatment of distal ACA aneurysms by comparing our results with recent endovascular and microsurgical series of distal ACA aneurysms.

MATERIALS AND METHODS

Between 2000 and 2008, a total of 22 consecutive patients (14 women; mean age, 58.4 years) with distal ACA aneurysms underwent coil placement at Barrow Neurological Institute. Clinical presentations, radiographic findings, endovascular management, and outcomes were reviewed retrospectively.

RESULTS

Of the 22 patients, 13 (59%) presented with subarachnoid hemorrhage. Six patients were HH grade I or II, 1 was grade III, 5 were grade IV, and 1 was grade V. Frontal lobe hematomas occurred in 5 patients with ruptured aneurysms. The mean aneurysm size was 7.5 mm (range, 2.8-25 mm); 55% were smaller than 7 mm. Twelve aneurysms (55%) arose from the origin of the callosomarginal artery (55%). Complete occlusion was achieved in 50% of the cases and near-complete occlusion in 45%. The few periprocedural complications included 1 retroperitoneal hematoma and 1 intraoperative rupture. Four patients had thromboembolic events adequately treated intraprocedurally with abciximab. No deaths occurred in the patients treated.

CONCLUSIONS

The characteristics of the patients and aneurysms treated in our series were comparable to previous reports of endovascular treatment of ACA aneurysms with respect to rupture status. Periprocedural morbidity and mortality rates in our series fared well compared with previous reports, as did our combined rate of complete or near-complete occlusions. Recent advances in endovascular devices and techniques have improved outcomes of distal ACA aneurysms.

Surgical Strategies and outcomes for distal anterior cerebral arteries aneurysms

Background:

Distal anterior cerebral artery (DACA) aneurysms are rare and their surgical treatment presents some unique difficulties. In this report, we present our experience of cases with DACA aneurysms.

Materials and Methods:

Among 80 patents with cerebral aneurysm operated on in the three-year period, 15 patients (18.75%) had DACA aneurysms, who were studied retrospectively. We analyze the specific clinical and radiological features, surgical strategies and prognostic factors affecting the surgical outcomes of these DACA aneurysms.

Results:

There were 10 male and 5 female patients harboring 16 DACA aneurysms. All patients presented with subarachnoid hemorrhage, 11 patients (73%) had intracerebral hematoma in their initial CT scan and four of them had associated intraventricular hemorrhage. Thirteen of the ruptured DACA aneurysms (86%) were small in size (less than 7 mm in diameter). Three patients (20%) had other associate aneurysms. In 14 patients (93%), a unilateral interhemispheric approach was used in their treatment, while pterional approach was used in one patient. Eleven patients (73%) had favorable outcomes and only one patient (7%) died. The follow-up data suggested that poor admission grade and initial Intracerebral hematoma (ICH) on brain scan portend an unfavorable prognosis.

Conclusions:

DACA aneurysms are usually small even when ruptured, they are usually associated with ICH more frequently than intracranial aneurysms in other locations. They should be aggressively treated even if very small because of their tendency to early rupture.

Thrombosed giant aneurysm of the distal anterior cerebral artery treated with aneurysm resection and proximal pericallosal artery-callosomarginal artery end-to-end anastomosis: Case report and review of the literature

BACKGROUND

Giant distal anterior cerebral artery (DACA) aneurysms are extremely rare, with only 32 cases reported in the literature. Most giant DACA aneurysms have features that make standard neck clipping difficult, and bypass surgery is sometimes required, although this surgery was performed in only three reported cases. This report presents the fourth case treated with bypass surgery.

CASE DESCRIPTION

A 69-year-old female presented with an unruptured thrombosed giant DACA aneurysm. She underwent wrapping operation 7 years before, but radiological imaging revealed enlargement of the aneurysm at the left pericallosal artery (PerA)-callosomarginal artery (CMA) junction. Before operation, three different strategies were considered for bypass surgery in case the neck could not be clipped. Aneurysm resection and left proximal PerA-CMA end-to-end anastomosis were successfully performed under intraoperative digital subtraction angiography (DSA) and motor-evoked potential (MEP) monitoring.

CONCLUSION

Most DACA aneurysms are located at the PerA-CMA junction. In some cases, adequate retrograde flow to the distal PerA from the posterior or middle cerebral artery can be expected, making distal PerA reconstruction unnecessary. Moreover, when the distal PerA is cut, proximal PerA-CMA end-to-end anastomosis can be easily performed because of reduced tension in both vessels. We therefore conclude that this strategy should be utilized for treating such patients. We also presented here the effectiveness of intraoperative modalities, such as intraoperative DSA and MEP monitoring, for performing a safe operation.

Aneurysms of the distal anterior cerebral artery: a clinical series

BACKGROUND AND PURPOSE

Distal anterior cerebral artery (DACA) aneurysms, also called pericallosal or A2 aneurysms, are rare and comprise about 1.5 to 9% of all intracranial aneurysms. In this study, a series of 10 patients with DACA aneurysms who were surgically treated in our clinic is presented and discussed, focusing on their clinical features and sur-gical outcomes.

MATERIAL AND METHODS

A total of 344 patients with cerebral aneurysms were operated on in our clinic and 10 patients (2.9%) with DACA aneurysms were studied retrospectively. All patients underwent a computed tomography (CT) scan followed by four-vessel digital subtraction angiography (DSA).

RESULTS

Initial CT revealed intracerebral haematoma (ICH) in 7 patients (70%) and in 2 of them the haematoma was over 3 cm in diameter. The pericallosal-callosomarginal bifurcation was the most common location in 9 patients (90%). Four cases (40%) showed multiple aneurysms. The mean waiting time for the operation was 4.8 days. Surgical clipping was performed in all the cases. Multiple aneurysms required two different craniotomies in the same session. The patients with ICH over 3 cm in diameter, in addition to poor preoperative grade, are likely to have a poor outcome, and so clinical grade is the definite factor affecting the surgical outcome of patients.

CONCLUSIONS

DACA aneurysms are usually small and bleeding occurs irrespective of their size because of the lack of resistant arachnoid membranes at the level of the pericallosal cisterns. All DACA aneurysms, even if very small in size or discovered incidentally, should be aggressively treated because of the high tendency to rupture.

Outcomes analysis of ruptured distal anterior cerebral artery aneurysms treated by endosaccular embolization and surgical clipping

Although endovascular surgery is now widely used to treat intracranial aneurysms, no comparative studies of clipping versus endovascular surgery to address distal ACA aneurysms at the same institution are available. We compared the results of these treatment modalities to address distal ACA aneurysms at our institution. We treated 68 patients with ruptured distal ACA aneurysms (endovascular surgery, n=13; clipping surgery, n=55). We performed a retrospective comparison of the treatment outcomes. To study the efficacy of endovascular surgery we classified all our cases into three types: type A were small-necked aneurysms, type B were wide-necked aneurysms on the parent artery, and type C were aneurysms in which the A3 portion of the ACA arose from the aneurysmal dome near the neck. Intraoperative hemorrhage occurred in 7.7% of aneurysms treated by endovascular surgery and in 34.5% treated by clipping surgery. In 7.7% of the endovascularly-treated aneurysms we noted coil migration during embolization surgery; venous infarction due to cortical vein injury occurred in 7.3% of clipped aneurysms. Of the endovascularly-treated aneurysms, 7.7% manifested post-embolization hemorrhage; 23.1% manifested coil compaction. In clipping surgery, postoperative rerupture occurred in 1.8% of the aneurysms; one patient presented with postoperative acute epidural hematoma. Clip dislocation was noted in 1.8% of aneurysms. Angiography was indicative of post-treatment vasospasm in 7.7% of aneurysms treated endovascularly and in 50.9% of the clipped aneurysms. The clinical outcome showed no significant difference between endovascular surgery and clipping surgery.

Endovascular treatment of distal anterior cerebral artery aneurysms: technical results and review of the literature

BACKGROUND

We sought to report our technical success and complications in treating distal anterior cerebral artery (ACA) aneurysms with coil embolization.

METHODS

We retrospectively reviewed all patients undergoing coil embolization of distal ACA aneurysms from September 1999 to March 2008. Patients were assessed for subarachnoid hemorrhage, fundus size, and fundus-to-neck ratio (F/N) < 2 or >or= 2. Technical success for aneurysms was assessed according to established criteria immediately post-procedure and at 6-month angiographic follow-up. Post-procedural outcomes were measured using the modified Rankin Scale (mRS) at discharge. A mRS <or= 2 for ruptured aneurysms or no change from baseline for unruptured aneurysms was considered a good clinical outcome.

RESULTS

Based on an intention-to-treat principle, we attempted embolization of 28 distal ACA aneurysms in 26 patients and were technically successful in 26 aneurysms (93%). Our mean age was 58 +/- 11 years. Thirteen presented with acute rupture. Average aneurysm size was 5.7 +/- 2.8 mm in our cohort with 20/28 (71%) having an F/N >or= 2. Seventeen aneurysms with an F/N >or= 2 and 5 with an F/N < 2 were completely obliterated or had minimal neck remnants at the end of the procedure (79%). Fourteen aneurysms underwent 6-month angiographic follow-up and were either completely obliterated or had a minimal residual neck remnant. Clinical outcomes were good in 12/13 unruptured patients (93%) at the time of discharge and in 6/13 ruptured patients (46%) with 90-day follow-up. Three patients had ischemic complications that were considered non-disabling, and 2 patients died from complications related to their initial subarachnoid hemorrhage. Two patients had an aborted procedure from failure to catheterize the aneurysm.

CONCLUSION

Endovascular treatment of distal ACA aneurysms can achieve good technical and clinical outcomes.

The anatomy of the callosomarginal artery: applications to microsurgery and endovascular surgery

BACKGROUND

The callosomarginal artery (CMA), the main branch of the pericallosal artery, courses in or near the cingulate sulcus and gives rises to 2 or more major cortical branches. There is confusion about the artery best fitting the definition of "callosomarginal artery." Distal anterior cerebral artery aneurysms represent 1.5% to 9% of intracranial aneurysms, and most often occur at the origin of the CMA. The microsurgical anatomic features of the CMA, its relationship with the pericallosal artery, and clinical implications are presented.

METHODS

The origin, course, branching pattern, and diameter of the CMA and its branches and its relationship with the pericallosal artery were studied in 60 cerebral hemispheres, including cadaveric dissections and angiographic images.

RESULTS

The CMA was present in 93.3% of hemispheres studied and arose mainly from A3 (55.2%), a mean of 3.11 +/- 1.90 cm from the anterior communicating artery. The mean diameter of the CMA at its origin was 1.53 +/- 0.36 mm. The CMA ran 1.28 +/- 0.89 cm until its first branch, describing an anterior convex curve backward and upward (60.7%). An average of 3 lesser branches originated from the CMA. The most consistent branch was the posterior internal frontal artery (67.9%). The mean diameter of the CMA branches was 0.93 +/- 0.33 mm.

CONCLUSION

These morphometric measurements can help neurosurgeons access lesions located in distal intracranial vessels. The vessel coursing the longest pathway in or near the cingulate sulcus and otherwise following Moscow's classic definition should be considered the CMA.

The influence of configuration and location of ruptured distal cerebral anterior artery aneurysms on their treatment modality and results: analysis of our casuistry and literature review

OBJECTIVE

To assess the influence of configuration and location of ruptured distal cerebral anterior artery aneurysms on their treatment modality and results.

METHOD

The influence of the aneurysm configuration (basic or complex configuration) and location (infracallosal or supracallosal) on the treatment-related radiological results (partial or complete aneurysm occlusion) and clinical outcome (favorable or unfavorable) was retrospectively analysed in all admitted patients with ruptured pericallosal aneurysms within the last 10 years. The expected benefit from each form of treatment was individually discussed.

RESULTS

During this period, 21 patients with ruptured pericallosal aneurysms (three previously coiled in other departments) had been admitted to our department. Within the endovascular group (ten patients), five infracallosal basic aneurysms presented a complete occlusion and favorable patient outcome. Three patients with infracallosal complex aneurysms presented a favorable outcome (two aneurysms were partially occluded and a frustrated procedure was replaced by clipping). Two supracallosal basic aneurysms showed a complete occlusion with one unfavorable outcome and one frustrated procedure followed by clipping and favorable outcome. In the surgical group (11 patients), five infracallosal complex aneurysms presented a complete occlusion with four favorable and one unfavorable outcomes. One patient with a supracallosal basic aneurysm presented a complete occlusion with a favorable outcome, and five patients with supracallosal complex aneurysms presented a complete occlusion in four cases and favorable outcome in all of them.

CONCLUSION

The results of this study suggest that patients with infracallosal basic configured aneurysms are expected to benefit from endovascular procedures, whereas better radiological and clinical results can be obtained in surgically treated patients harboring supra- or infracallosal aneurysms of complex configuration.