Posterior cerebral artery (PCA)-accessory PCA (hyperplastic anterior choroidal artery) anastomosis detected on magnetic resonance angiography

PURPOSE

To describe a case of posterior cerebral artery (PCA)-accessory PCA (hyperplastic anterior choroidal artery) anastomosis detected on magnetic resonance angiography.

METHODS

A 76-year-old man with a history of cerebral infarction underwent cranial magnetic resonance (MR) imaging and MR angiography of the intracranial region for the evaluation of brain and vascular lesions. The MR machine was a 3-Tesla scanner. MR angiography was performed using a standard three-dimensional time-of-flight technique.

RESULTS

There were two right PCAs. The parieto-occipital and calcarine arteries of the right PCA arose from the right ICA, indicative of accessory PCA, and there were three stenotic lesions at the proximal segment of this artery. The temporal artery of the right PCA originated from the basilar artery. A small anastomotic channel between these two arteries was identified on partial maximum intensity projection (MIP) images. Computed tomography angiography was additionally performed and the findings were confirmed.

CONCLUSION

We speculated that the pressure gradient between the PCA and the accessory PCA enlarged the anastomotic channel. Partial MIP images are useful for diagnosing small arterial variations using MR angiography.

Twig-like Middle Cerebral Artery: Case Series in a European Population

OBJECTIVES

Twig-like middle cerebral artery (MCA) is a rare anomaly where the M1 MCA is partially or completely replaced by a plexiform network. It has been described in angiographic series from Asian and South-American cohorts, but has not yet been reported in a European population.

METHODS

The digital subtraction angiograms (DSAs) of adult patients referred to a single neurovascular center for a diagnostic hypothesis of moyamoya arteriopathy (MMA) from 2018 to 2023 were prospectively and retrospectively checked by experienced neuroradiologists for identifying patients with twig-like MCA. The angioarchitecture of twig-like MCA was systematically evaluated and described.

RESULTS

Five of 30 (16.7%) male patients (mean age 55.8 + 14.7 years) of European ancestry were identified as having twig-like MCA. The clinical presentations were ischemic stroke (2 of 5), hemorrhagic stroke (1 of 5), and headache (2 of 5). All patients showed a unilateral involvement on DSA and in 1 of 5 (20%) an intracranial aneurysm was found. DSA was used to confirm the diagnosis of twig-like MCA and define the angioarchitecture and associated anomalies. An accessory MCA and recurrent artery of Heubner were found in 3 of 5 (60%) cases, feeding the network together with the anterior choroidal artery (4 of 5, 80%).

CONCLUSIONS

Twig-like MCA is a rare vascular anomaly, but it seems to be less rare than expected among adult European patients with suspected MMA on noninvasive neuroimaging studies. DSA is fundamental for a reliable differential diagnosis and should not be omitted in these patients.

Accessory posterior cerebral artery (hyperplastic anterior choroidal artery) associated with contralateral accessory middle cerebral artery incidentally diagnosed by magnetic resonance angiography

PURPOSE

To describe a case of accessory posterior cerebral artery (PCA) [hyperplastic anterior choroidal artery (AChA)] associated with contralateral accessory middle cerebral artery (MCA) incidentally diagnosed by magnetic resonance (MR) angiography.

METHODS

A 71-year-old man with paroxysmal atrial fibrillation underwent cranial MR imaging and MR angiography of the intracranial region using a 1.5-T scanner for the evaluation of brain and vascular lesions.

RESULTS

On MR angiography, two right PCAs of equal size arose from the internal carotid artery instead of the basilar artery. Additionally, a small left MCA branch arose from the proximal A2 segment of the anterior cerebral artery (ACA).

CONCLUSION

One of the branches of the PCA rarely arises from the AChA. This variation is referred to as a hyperplastic AChA or accessory PCA. The latter name was recently proposed and may be more appropriate than the former name. An MCA branch arising from the ACA is called an accessory MCA. It is a frontal branch of two types: proximal-origin and distal-origin. The distal-origin accessory MCA arises from the distal A1 segment, A1-A2 junction or proximal A2 segment. Distal-origin accessory MCAs are rare. Our patient had two rare variations: an accessory right PCA and a distal-origin accessory left MCA. To identify cerebral arterial variations, especially accessory MCA, volume-rendering images are more useful than maximum-intensity projection images on MR angiography.

Replaced posterior cerebral artery

PURPOSE

Replaced posterior cerebral artery (PCA), defined as a hyperplastic anterior choroidal artery (AChA) supplying all branches of the PCA, is an extremely rare anatomical variation. To the best of our knowledge, there are only a few reports of replaced PCA.

METHODS

Herein, we report a case of replaced PCA diagnosed by digital subtraction angiography.

RESULTS

A 76-year-old woman visited a neurosurgical clinic because of headache and vertigo. Magnetic resonance imaging and magnetic resonance angiography incidentally revealed a left internal carotid artery aneurysm. She was referred to our hospital for further examination and treatment of the unruptured intracranial aneurysm. Left internal carotid angiography revealed a paraclinoid aneurysm. We also incidentally found an anomalous hyperplastic AChA distal to the aneurysm. This hyperplastic AChA supplied not only the AChA territory but also the entire PCA territory. No vessels that could be a normal AChA or posterior communicating artery were identified along the left internal carotid artery. Vertebral angiography demonstrated that the left PCA was not visualized. With these findings, we diagnosed anomalous hyperplastic AChoA in this case as replaced PCA.

CONCLUSION

Careful imaging assessment is important to identify replaced PCA. Both direct findings of a hyperplastic AChA course and perfusion territory and indirect findings of the absence of the original PCA are useful in the diagnosis of replaced PCA.

Internal carotid artery-persistent primitive anterior choroidal artery aneurysms: report of two cases and literature review

PURPOSE

Persistent primitive anterior choroidal artery (PPAChA) is a rare vascular anomaly. The clinical course of internal carotid artery (ICA)-PPAChA aneurysms has not been well described.

CASE REPORTS

We report two patients with an ICA-PPChA aneurysm and summarize previously reported cases.

RESULTS

Including our two, a total of 10 patients with an ICA-PPAChA aneurysm have been reported. Data were not described for one. Among the remaining nine, five patients (56%) experienced aneurysmal rupture. Five patients underwent surgical clipping and four underwent endovascular coiling. The procedure was completed in all but one patient who had a tiny branch artery adherent to the aneurysm; this patient was converted from clipping to aneurysm coating with a cotton sheet. Among the other eight patients, one who underwent coiling experienced an internal capsule infarction. The remaining seven had a satisfactory postoperative course; however, an asymptomatic occlusion of the PPAChA at its origin was noted on postoperative angiography in one.

CONCLUSION

PPChA is associated with a high incidence of aneurysm formation and rupture. During treatment of ICA-PPAChA aneurysms, obstruction of the PPAChA and any surrounding perforating arteries should be avoided to prevent ischemic stroke.

Clipping of Unruptured Anterior Choroidal Artery Aneurysms Together with Small Branches: Safety Confirmation Using Intraoperative Indocyanine Green Video-Angiography and Intraoperative Neurophysiological Monitoring

BACKGROUND

In treating anterior choroidal artery (AChA) aneurysms, preserving the AChA main trunk is of course necessary to prevent postoperative ischemic complications. However, in practice, complete occlusions are often limited by small branches.

OBJECTIVE

We aimed to demonstrate that even in cases where complete occlusion of the AChA aneurysm is complex due to small branches, complete occlusion can be safely achieved using indocyanine green video-angiography and intraoperative neurophysiological monitoring (IONM).

METHODS

We performed a retrospective review of all unruptured AChA aneurysms surgically treated at our institution from 2012 to 2021. All available surgical videos were reviewed to find AChA aneurysms clipped with small branches; clinical and radiological data were collected for these cases.

RESULTS

Among 391 cases of unruptured AChA aneurysms treated surgically, 25 AChA aneurysms were clipped with small branches. AChA-related ischemic complications occurred in 2 cases (8%) without retrograde indocyanine green filling to the branches. These 2 cases had changes in IONM. There were no ischemic complications in the remaining cases with retrograde indocyanine green filling to the branches and no change in IONM. During an average follow-up of 47 months (12-111 months), a small residual neck was observed in 3 cases (12%) and recurrence or progression of the aneurysm was observed in only 1 case (4%).

CONCLUSIONS

The surgical treatment of AChA aneurysms carries the risk of devastating ischemic complications. Even in cases where complete clip ligation seems impossible due to small branches associated with AChA aneurysms, complete occlusion can be safely achieved using indocyanine green video-angiography and IONM.

Clinical Efficiency of an Artificial Intelligence-Based 3D-Angiography for Visualization of Cerebral Aneurysm: Comparison with the Conventional Method

PURPOSE

Artificial intelligence (AI)-based three-dimensional angiography (3D-A) was reported to demonstrate visualization of cerebral vasculature equivalent to that of three-dimensional digital subtraction angiography (3D-DSA). However, the applicability and efficacy of the AI-based 3D‑A algorithm have not yet been investigated for 3D-DSA micro imaging. In this study, we evaluated the usefulness of the AI-based 3D‑A in 3D-DSA micro imaging.

MATERIALS AND METHODS

The 3D-DSA micro datasets of 20 consecutive patients with cerebral aneurysm (CA) were reconstructed with 3D-DSA and 3D‑A. Three reviewers compared 3D-DSA and 3D‑A in terms of qualitative parameters (degrees of visualization of CA and the anterior choroidal artery [AChA]) and quantitative parameters (aneurysm diameter, neck diameter, parent vessel diameter, and visible length of AChA).

RESULTS

Qualitative evaluation of diagnostic potential revealed that visualization of CA and the proximal to middle parts of the AChA with 3D‑A was equal to that with conventional 3D-DSA; in contrast, visualization of the distal part of the AChA was lower with 3D‑A than with 3D-DSA. Further, regarding quantitative evaluation, the aneurysm diameter, neck diameter, and parent vessel diameter were comparable between 3D‑A and 3D-DSA; in contrast, the visible length of the AChA was lower with 3D‑A than with 3D-DSA.

CONCLUSIONS

The AI-based 3D‑A technique is feasible and evaluable visualization of cerebral vasculature with respect to quantitative and qualitative parameters in 3D-DSA micro imaging. However, the 3D‑A technique offers lower visualization of such as the distal portion of the AChA than 3D-DSA.

How I do it? Basilar bifurcation and left anterior choroidal artery aneurysms clipping

BACKGROUND

Despite advancements in endovascular techniques, microsurgical treatment for posterior circulation aneurysms remains challenging.

METHOD

This report highlights the successful clipping surgery of a 17-year-old female patient with an aneurysm located at the basilar artery (BA) bifurcation and left anterior choroidal artery (AChoA). To improve exposure, the posterior communicating artery was transected. A straight fenestrated clip was then placed to repair the BA bifurcation aneurysm, followed by a curved mini clip for the AChoA aneurysm.

CONCLUSION

This report demonstrates the nuances of microsurgery in the treatment of select complex cases, which can benefit from microsurgery to achieve optimal treatment outcomes.

Treatment of Ruptured Anterior Choroidal Artery Aneurysms by Acute Coiling Followed by Flow Diversion

BACKGROUND

Flow-diverter treatments are successful endovascular treatments in protecting important perforating branches during aneurysm treatments. Because these treatments are performed under antiplatelet therapy, acute flow-diverter treatments in ruptured aneurysms are still controversial. Acute coiling followed by flow diversion has emerged as an intriguing and feasible treatment option for ruptured anterior choroidal artery aneurysm treatment. As a single-center retrospective case series study, this study reported the clinical and angiographic results of staged endovascular treatment in patients with a ruptured anterior choroidal aneurysm.

METHODS

This is a single-center retrospective case series study between March 2011 and May 2021. Patients with ruptured anterior choroidal aneurysm received flow-diverter therapy in a different session after acute coiling. Patients treated with primary coiling or only flow diversion were excluded. Preoperative demographic and presenting symptoms, aneurysm morphology, perioperative and postoperative complications, and long-term clinical and angiographic outcome as measured using the modified Rankin Scale and O'Kelly Morata Grading scale and also Raymond-Roy occlusion classification respectively.

RESULTS

Sixteen patients underwent coiling in the acute phase to undergo flow diversion later. The mean maximum aneurysm diameter is 5.44 ± 3.39 mm. All patients had a subarachnoid hemorrhage and were treated acutely between days 0 and 3 of acute bleeding. The mean age at the presentation was 54.12 ± 12 years (32-73 years). Two patients (12.5%) had minor ischemic complications, which are seen on magnetic resonance angiography as clinically silent infarcts, after the procedure. One patient (6.2%) had a technical complication with the flow-diverter shortening and deployed a second flow diverter telescopically. No mortality or permanent morbidity was reported. The mean interval time between the 2 treatments was 24.06 ± 11.83 days. All patients were followed up with digital subtraction angiography; 14/16 patients (87.5%) had aneurysms that were completely occluded and 2/16 (12.5%) showed near-complete occlusion. Mean follow-up was 16.62 ± 3.22 months; all patients had modified Rankin Scale scores ≤2; 14/16 (87.5%) had a total occlusion 14/16 (87.5%) had near-complete occlusion. None of the patients had retreatment or rebleeding.

CONCLUSIONS

Staged treatment of ruptured anterior choroidal artery aneurysms with acute coiling and flow-diverter treatment after recovery from subarachnoid hemorrhage is safe and effective. In this series, no cases of rebleeding occurred during the interval between coiling and flow diversion. Staged treatment should be considered a valid option in patients with challenging ruptured anterior choroidal aneurysms.

Elevated neutrophil-related immune-inflammatory biomarkers in acute anterior choroidal artery territory infarction with early progression

OBJECTIVE

The anterior choroidal artery territory (AChA) infarction has a high rate of progression and poor functional prognosis. The aim of the study is to search for fast and convenient biomarkers to forecast the early progression of acute AChA infarction.

METHODS

We respectively collected 51 acute AChA infarction patients, and compared the laboratorial index between early progressive and non-progressive acute AChA infarction patients. The receiver-operating characteristics curve (ROC) analysis was used to determine the discriminant efficacy of indicators that had statistical significance.

RESULTS

The white blood cell, neutrophil, monocyte, white blood cell to high-density lipoprotein cholesterol ratio, neutrophil to high-density lipoprotein cholesterol ratio (NHR), monocyte to high-density lipoprotein cholesterol ratio, monocyte to lymphocyte ratio, neutrophil to lymphocyte ratio (NLR), and hypersensitive C-reaction protein in acute AChA infarction are significantly higher than healthy controls (P < 0.05). The NHR (P = 0.020) and NLR (P = 0.006) are remarkably higher in acute AChA infarction patients with early progression than non-progression. The area under the ROC curve of NHR, NLR, the combine of NHR and NLR are 0.689 (P = 0.011), 0.723 (P = 0.003), 0.751 (P < 0.001), respectively. But there are no significant differences in efficiency between NHR and NLR and their combined marker in predicting progression (P > 0.05).

CONCLUSION

NHR and NLR may be significant predictors of early progressive patients with acute AChA infarction, and the combination of NHR and NLR could be a preferable prognostic marker for AChA infarction with early progressive course in acute stage.

Complete duplication of the posterior cerebral artery

PURPOSE

Variations of the posterior cerebral artery (PCA) are rare, excluding aplasia or hypoplasia of the P1 segment. To the best of our knowledge, there are few reports of complete duplication of the PCA.

METHODS

Herein, we report a case of complete duplication of the PCA diagnosed by 1.5 T magnetic resonance angiography.

RESULTS

A 55-year-old woman visited our hospital for cerebrovascular disease screening. Magnetic resonance angiography revealed two right PCAs with similar diameters. One PCA originated as the P1 segment of the PCA branching from the basilar artery, and the other was the fetal-type posterior communicating artery (PCoA) branching from the internal carotid artery (ICA). Neither PCA supplied the right anterior choroidal artery (AChA) territory. Bilateral PCoAs branched from the same position as each ICA, respectively. The right AChA branched from the ICA distal to the PCoA branching position.

CONCLUSION

Careful imaging assessment is important for identifying complete duplication of the PCA. In addition to the direct findings of AChA identification, the indirect findings of the PCoA branching position and that the PCAs did not supply the AChA territory were also useful for diagnosis in this case.

Role of the anterior choroidal artery in the endovascular treatment of brain arteriovenous malformations

The anterior choroidal artery (AchA) is a very important vessel that supplies certain crucial structures that have poor collateral circulation. When the AchA is recruited to supply brain arteriovenous malformations (BAVMs), can the AchA act as a safe path through which endovascular treatment (EVT) be performed? As few studies or reports have investigated this matter, we performed a review to expound upon the role of the AchA in the EVT of BAVMs. In this review, we discussed the anatomy and variation of the AchA, the angioarchitecture of BAVMs fed by the AchA, the status of EVT for BAVMs and its associated problems and their solutions, the choice of embolic materials, new EVT techniques, the complications and prognoses of EVT through the AchA, etc. The review revealed that although EVT of BAVMs through the AchA is challenging and can result in unpredictable complications, it may be an appropriate option prior to surgery and radiation therapies or serve as a curative procedure. A complete and thorough understanding of the functional anatomy and variant of the AchA and proper EVT techniques are crucial for successful embolization of BAVMs via the AchA.

Duplicated fetal posterior cerebral artery in a patient with a ruptured fetal posterior cerebral artery aneurysm: a cerebrovascular variant

BACKGROUND

The most common neurovascular variant is the fetal posterior cerebral artery (FPCA), in which the P1 branch is absent or hypoplastic, and the majority of P2 supply is derived from the anterior circulation. While there are reports of hyperplastic anterior choroidal arteries (AChA) with supply to the temporo-occipital and calcarine regions, no reports of a duplicated FPCA exist.

METHODS

This case report describes a patient with a ruptured right FPCA aneurysm. Digital subtraction angiogram (DSA) revealed an artery with origin distal to the FPCA associated with the aneurysm. This was not consistent with a typical AChA. The FPCA associated with the aneurysm had the typical origin, course, and supply of a FPCA. The distal FPCA had a similar course of a typical FPCA with significant supply to the typical PCA territory. The patient underwent successful clipping of the aneurysm, and the duplicated FPCA was identified during the craniotomy.

RESULTS

The features of this duplicate FPCA, which has not been previously described, are discussed in comparison to another variant, the hyperplastic, anomalous AChA. The artery described in this report does not fit the typical criteria of this AChA variant. Therefore, the authors outline this variant as a duplicated FPCA.

CONCLUSION

Recognition of variant cerebrovascular anatomy is vital to neurosurgeons and interventional neuroradiology specialists. FPCA aneurysms require special management considerations and are often more challenging to treat. This report discusses a duplicated FPCA. To our knowledge, this is the first description of this variant. A duplicated FPCA carries important management considerations in the management of neurovascular pathology.

Predictors of Ischemic Complication in Anterior Choroidal Artery Aneurysm Repair

BACKGROUND

Treatment of anterior choroidal artery (AchoA) aneurysms is challenging because of the risk of artery injury. The objective of the study was to evaluate the incidence and predictors of AchoA infarction in patients who underwent surgical or endovascular procedure.

METHODS

We included 123 patients with AchoA aneurysms treated by surgical clipping (n = 62; 50.4%) or endovascular coiling, including flow diverter placement (n = 61; 49.6%). The clinical and radiological data were retrospectively analyzed. AchoA infarction was defined as the presence of a hyperintense signal on diffusion-weighted imaging in the area of AchoA, including the posterior limb of the internal capsule.

RESULTS

AchoA infarction was detected in 8 cases (6.5%), with similar incidence in both groups (6.5% [4/62] vs. 6.6% [4/61]). It occurred in ruptured aneurysms more frequently than in unruptured aneurysms (14.3% [6/42] vs. 2.5% [2/81], P = 0.019). In the surgical group, all 4 affected patients had a non-proximal type AchoA, whereas in the non-infarction group, 9 patients (15.5%) had a non-proximal type AchoA (P = 0.001). In the endovascular group, the incidence was higher in patients with ruptured aneurysms (17.3% [4/23] vs. 0% [0/38], P = 0.017) and lower in patients with pre-admission antiplatelet therapy (0% [0/39] vs. 18.8% [4/22], P = 0.014).

CONCLUSIONS

Repair of an AchoA aneurysm is associated with the risk of incurring post-procedural AchoA infarction. Surgical clipping and endovascular coiling have similar complication rates, but risk factors specific to each intervention exist. Careful surgical planning to avoid these risk factors in each therapeutic modality may improve patient outcomes.

Hydration-induced rapid growth and regression after indirect revascularization of an anterior choroidal artery aneurysm associated with Moyamoya disease: A case report

The prevalence of aneurysm formation in adults with Moyamoya disease (MMD) is higher than that in the general population. The treatment strategy is often individualized based on the patient's disease characteristics. A 22-year-old man was diagnosed with MMD after presenting a small thalamic intracerebral and subarachnoid hemorrhage in the quadrigeminal cistern. Cerebral angiography revealed a small aneurysm (2.42 mm) in the left anterior choroidal artery. Since the hemodynamics in the left hemisphere was compromised, an indirect bypass surgery was performed. The patient's condition deteriorated postoperatively because of poor perfusion of the internal carotid artery, and massive hydration was required. During neurocritical care, the aneurysm increased in size (5.33 mm). An observation strategy was adopted because of the distal aneurysmal location and the high risk involved. Subsequently, the patient recovered, and newly developed collateral flow appeared from the external carotid artery. Additionally, a dramatic size reduction of the aneurysm (1.51 mm) was noticed. Our case suggests that MMD-related dissecting aneurysms on a distal cerebral artery, which present a high risk of embolization, could be managed by indirectly reducing the hemodynamic burden. Massive hydration in such cases should be avoided or balanced to avoid the risk of rapid growth and aneurysm rupture.

Three-Dimensional Angioarchitecture of Rete Middle Cerebral Artery Anomalies and the Clinical Significance

PURPOSE

Rete middle cerebral artery (MCA) anomaly is characterized by a web-like network of arteries involving the first MCA segment (M1) and a normal downstream MCA. The detailed composition of this anomaly and the hemodynamic impacts on cerebral perfusion are rarely addressed. The purpose of this study was to elucidate the anatomical and hemodynamic perspectives of the rete MCA anomaly.

METHODS

From August 2020 to December 2021, 4 rete MCA anomalies were identified at Shuang Ho hospital. Clinical information, perfusion magnetic resonance (MR) imaging, and angiographic images were collected. Detailed angioarchitecture, including types of arterial feeders and extent of rete involvement, were analyzed based on three-dimensional volume-rendering reconstruction images obtained from the catheter-based angiographies.

RESULTS

Despite their variable clinical presentations (two hemorrhage, one ischemia, and one asymptomatic), all cases shared common angiographic findings as follows: (1) the internal carotid artery did not connect directly to the rete, (2) the anterior choroidal artery (AChA) was the artery constantly supplying the rete and (3) there was a watershed zone shift toward MCA territory. The perfusion MR cerebral blood flow map was symmetric in all studied cases.

CONCLUSION

The AChA is an artery constantly supplying the rete, which suggests that the angioarchitectural features associated with this anomaly may be the result of both congenital and acquired compensatory processes. Cerebral perfusion remains preserved at the lesion side, despite angiographic evidence of watershed zone shift. These findings will be important for making better clinical judgments about this condition.

Anatomy of the Intracranial Arteries: The Internal Carotid Artery

The internal carotid artery is an elegant vessel that is segmentally defined by adjacent anatomic landmarks and defined branch vasculature. Here we describe the segmental and branch angiographic anatomy of the internal carotid artery with particular regard to embryologic development, clinically important anastomotic pathways, and cerebrovascular diseases, such as aneurysm development.

Variations in the branching patterns of the anterior choroidal artery: an angiographic study with special reference to temporal lobe epilepsy surgery

BACKGROUND

The preservation of the anterior choroidal artery (AChA) is essential for avoiding neurological sequelae after mesial temporal lobe epilepsy (mTLE) surgery. The purpose of this study is to reveal the anatomical variation in which the perforating branches arise from the plexal segment of the AChA by using a modern neuroimaging modality.

METHODS

This study analyzed 3D rotational angiography (3DRA) images from 56 subjects. The AChA and perforating branches were visualized using slab MIP. We analyzed branching patterns, courses of the perforating arteries arising from the plexal segment of the AChA, and the anastomosis of the AChA with other cerebral arteries.

RESULTS

The slab MIP applied to 3DRA visualized one or more perforating branches from the AChA in 92.9% of cases. The presence of perforating branches arising from the AChA plexal segment was 17.3%. Most of the branching points of plexal perforators were likely located in the operative field during hippocampal resection. The course of the AChA plexal perforators included the posterior limb of the internal capsule. Anastomosis with other cerebral arteries was visualized in 25% of the AChA with plexal perforators.

CONCLUSIONS

3DRA slab MIP was useful for visualizing the perforating branches of the AChA. Our results showed the possibility that surgical manipulation of the choroid plexus may cause infarction in the AChA territory. We suggest that the existence of the AChA plexal perforators should be recognized to further enhance the safety of hippocampal resection for mTLE.

Flow recovery after posterior clinoidectomy for surgical clipping of anterior choroidal aneurysm

Inadvertent flow alterations in the parent artery during microsurgical clipping might produce postoperative ischemic complications. Intraoperative recognition of such alterations and its correction might improve operative outcomes in these patients. We present the case of a thirty-five-year-old male with an incidental small left anterior choroidal aneurysm. Microsurgical clipping induced an external compression of the anterior choroidal artery against the posterior clinoidal process which was identified in situ through surgical exploration and the loss of arterial doppler signal in the vessel. After failed attempts at clip repositioning, a posterior clinoidectomy was performed to decompress the artery. This resulted in arterial flow recovery. The aneurysm was successfully treated, and a severe ischemic complication was likely avoided. This intraoperative phenomenon has not yet been described in the literature.

Intraoperative motor-evoked potential monitoring during coil embolization for anterior choroidal artery aneurysms

PURPOSE

Intraoperative motor-evoked potential (MEP) monitoring is widely used in the neck clipping of cerebral aneurysms. Little is known regarding the usefulness of intraoperative MEP monitoring in endovascular aneurysm surgery. The purpose of this study was to validate the feasibility of intraoperative MEP monitoring during the coil embolization of anterior choroidal artery (AChA) aneurysms.

METHODS

Clinical and angiographic data of consecutive patients who underwent coil embolization for unruptured AChA aneurysms with or without intraoperative MEP monitoring between January 2014 and December 2018 at our institute were abstracted and analyzed retrospectively.

RESULTS

Twenty-three unruptured AChA aneurysms were treated. Eleven patients received MEP monitoring, and three of them experienced intraoperative reduction or disappearance of the MEP wave. Even during MEP changes, AChA filling showed no change in any of the three cases. Although one case with MEP monitoring encountered the disappearance of AChA filling, there was no change in MEP. This might be due to retrograde filling of the AChA from the anastomosis with the lateral posterior choroidal artery. AChA blood flow detected by angiography did not always reflect MEP status. When comparing the presence or absence of MEP monitoring, the volume embolization ratio of coiled aneurysms was significantly better in the MEP group.

CONCLUSION

Intraoperative MEP monitoring during endovascular coiling for AChA aneurysms may be feasible. AChA blood flow detected by angiography does not always reflect MEP status.

Multiple anterior choroidal arteries and perioperative ischemic complications in unruptured anterior choroidal artery aneurysms treated with microsurgical clipping

BACKGROUND

This study aimed to identify the association between the number of anterior choroidal arteries (AchoAs) and procedure-related ischemic complications in microsurgical clipping of unruptured AchoA aneurysms.

METHODS

We retrospectively reviewed the clinical, radiological, and intraoperative findings of 153 patients with unruptured AchoA aneurysms treated with microsurgical clipping between January 2012 and November 2020 in a single tertiary institution. Intraoperative video clips were reviewed, and the AchoA type was categorized into two according to the number of AchoAs: (1) single-type group with single origin and single branch and (2) multiple-type group with duplicated origin or divided multiple branches. Uni- and multivariate analyses were performed to assess the relationship between clinical and radiological factors and perioperative ischemic complications.

RESULTS

Of the 153 patients, 52 (34%) were categorized as multiple-type group. The frequency of perioperative ischemic complications, including decreased intraoperative motor evoked potential (MEP), silent infarction, and postoperative ischemic symptoms, was significantly higher in the multiple-type group than in the single-type group (13 [25%] vs 6 [5.9%], p = 0.001). Multivariate logistic regression analysis showed that multiple-type group (odds ratio [OR], 3.725; 95% confidence interval [CI], 1.171-11.845, p = 0.026) and multilobulated shape (OR, 9.512; 95% CI, 2.093-43.224; p = 0.004) were significantly associated with perioperative ischemic complications. Among 9 patients with decreased MEP, postoperative ischemic symptoms developed in 2 patients after clip adjustment.

CONCLUSIONS

Multiple-type AchoA aneurysms and multilobulated shape are significantly correlated with perioperative ischemic complications. Postoperative ischemic complications can be minimized by recognizing these variations and using multimodal approach with MEP monitoring.

Clinical Study of Cerebral Ischemia in Moyamoya Disease from the View of Development of the Anterior Choroidal Artery

OBJECTIVES

The anterior choroidal artery (AchA) is one of the collateral vessels in moyamoya disease (MMD). The incidence of cerebral ischemia in MMD was analyzed through the association between development of the AchA and advancement of MMD stage.

MATERIALS AND METHODS

Twelve patients of MMD with cerebral ischemia (infarction; 9 patients, transient ischemic attack; 3 patients) were enrolled. Advancement of MMD was evaluated using Suzuki's stage. The grades in Suzuki's stage were subclassified into a non-progressive stage for grades 1 and 2, and a progressive stage for grades 4 and 5. Dilatation of the AchA was judged as the presence of development of this artery. Development of the AchA was grouped into proximal type and proximal and distal type.

RESULTS

Most frequent locations of infarcts were the anterior and parietal lobes in 6 patients each. Development of the AchA was confirmed on the ischemic side in all patients and on the non-ischemic side in 9 patients. Development of the AchA in the progressive stage was limited in the proximal and distal type on both sides. Development of the AchA in the non-progressive stage was the proximal type on the ischemic side.

CONCLUSIONS

The cause of cerebral ischemia was possibly associated with inadequate blood supply of the AchA in the non-progressive stage, and the lower blood flow from the internal carotid artery (ICA) in the progressive stage. Disparity between collateral blood flow from the AchA and the blood flow from the ICA was considered to relate to incidence of cerebral ischemia in MMD.

Lesion Trapping with High-Flow Bypass for Ruptured Internal Carotid Artery Blood Blister-Like Aneurysm Has Little Impact on the Anterior Choroidal Artery Flow: Case Series and Literature Review

OBJECTIVE

To examine the relationship between trap location and cerebral infarction in the anterior choroidal artery (AChA) region and associated risks in ruptured internal carotid artery blood blister-like aneurysm (BLA) treatment with high-flow bypass and lesion trapping.

METHODS

We included 26 patients diagnosed with BLAs and treated with high-flow bypass and trapping. We examined clinical characteristics including age, aneurysm trap location, final prognosis, cerebral infarction on postoperative magnetic resonance imaging, and modified Rankin Scale score at discharge. We also searched the literature for similar studies.

RESULTS

The modified Rankin Scale score at discharge was 0-2 in 20 patients, 3-5 in 2 patients, and 6 in 2 patients. In 19/26 patients (73.1%), the trapped segment was between the posterior communicating (PcomA) and the ophthalmic arteries. In 2 patients (7.7%), the trapped segment included the PcomA and the AChA; in 4 patients (15.4%), the trapped segment was within the PcomA. In these patients, the PcomA was occluded, and blood from the high-flow bypass flowed out to the AChA alone. No patient showed cerebral infarction. Our systematic review identified 70 patients. Of all 96 patients, 12 had AChA cerebral infarction; however, the infarction affected the prognosis of only 2 patients.

CONCLUSIONS

When treating BLAs with high-flow bypass and lesion trapping, the frequency of AChA cerebral infarction is low even when the PcomA is occluded, leaving the AChA as the only outflow vessel during high-flow bypass. However, PcomA occlusion may be associated with risks when treating patients with advanced arteriosclerosis near C1-2.

Anomalous hyperplastic anterior choroidal artery and its mimicker: a case series

The anomalous hyperplastic anterior choroidal artery (AchoA) is a rare anomaly due to incomplete distal annexation between the primitive AchoA and posterior cerebral artery (PCA). It is often misdiagnosed or misunderstood as a duplicated or fetal type PCA because of its supply distribution. In addition, its aneurysm incidence is much higher than the overall aneurysm incidence of AchoA. Thus, endovascular procedures or surgery without comprehensive understanding of this anomaly can cause critical complications. Herein, we present a case series of anomalous hyperplastic AchoA and its mimicker, along with schematic images for comprehensive understanding.

Duplicated Middle Cerebral Artery Aneurysms Treated by Coil Embolization; A Report of Two Cases and Literature Review

BACKGROUND

Duplication of the middle cerebral artery (DMCA) is an anomalous vessel arising from the internal carotid artery (ICA). Aneurysms at the origin of a DMCA have been reported; however, most have been treated with clipping surgery. Here, we describe two cases of aneurysms at the origin of a DMCA treated with coil embolization.

CASE PRESENTATION

Case 1: A seventy-three year-old man presented with severe headache and was diagnosed with subarachnoid hemorrhage (SAH). Digital subtraction angiography (DSA) and 3-dimensional (3-D) DSA showed an aneurysm arising from a DMCA. Coil embolization was performed with DMCA patency. The patient had an uneventful postoperative course. CASE 1: A 44-year-old woman presented with a history of clipping for an IC-anterior choroidal artery (AchA) aneurysm 8 years prior. Magnetic resonance imaging (MRI) showed regrowth of the aneurysm. 3-D DSA showed an IC-DMCA aneurysm located laterally and distal to the AchA. The DMCA arose from the bottom of the aneurysm. Coil embolization was performed without DMCA occlusion and showed no postoperative ischemic changes.

CONCLUSION

An IC-DMCA aneurysm is rare and may be misdiagnosed as an AchA aneurysm. Clinicians should perform a 3D-DSA evaluation if the aneurysm arises from the lateral wall of the IC to obtain a precise diagnosis and to preserve the DMCA during coil embolization.

Improved Depictions of the Anterior Choroidal Artery and Thalamoperforating Arteries on 3D-CTA Images Using Model-based Iterative Reconstruction

RATIONALE AND OBJECTIVES

To evaluate the depictability of intracranial small arteries using high-resolution CTA with model-based iterative reconstruction (MBIR).

MATERIALS AND METHODS

We retrospectively analyzed 21 patients who underwent brain 3D-CTA. Axial and volume-rendered (VR) images were reconstructed from the 3D-CTA raw data using adaptive statistical image reconstruction (ASIR) and MBIR. As a quantitative assessment, intra-arterial CT values of the ICA and contrast-to-noise ratio were measured to evaluate vessel enhancement. Additionally, CT values and standard deviations (SDs) of CT values and signal to noise ratio in white matter parenchyma were measured to evaluate background noise. As a qualitative assessment, the degree of vessel depictability in the anterior choroidal artery (AchoA) and the perforating branches of thalamoperforating arteries (TPA) on VR images using two different reconstruction algorithms was visually evaluated using a 3-point grading system.

RESULTS

The CT value of the ICA [605.27± 89.76 Hounsfield units (HU)] was significantly increased and the SD value (i.e., image noise) of the white matter parenchyma [6.79 ± 0.81(HU)] was decreased on MBIR compared with ASIR [546.76 ± 85.27 (HU)] and [8.04 ± 1.08 HU)] (p <.05 for all). Contrast-to-noise ratio of ICA [84.48 ± 20.17] and signal to noise ratio of white matter [6.18 ± 0.75] with MBIR were significantly higher than ASIR [65.98 ± 13.08] and [5.28 ± 0.78] (p < 0.05 for all). In addition, depictions of the AchoA and TPA on VR images were significantly improved using MBIR compared with ASIR (p < 0.05).

CONCLUSION

MBIR allows depiction of small intracranial arteries such as AchoA and TPA with better visibility than ASIR without increasing the dose of radiation and the amount of contrast agent.

The anterior one third of the posterior limb of the internal capsule is also supplied by the anterior choroidal artery

PURPOSE

It is universally recognized that the anterior choroidal artery (AChA) supplies the posterior two-third of the posterior limb of internal capsule (PLIC). On the other hand, the blood supply to the anterior one third of the PLIC has remained undetermined. We posit the anterior one third of the PLIC is also supplied by the AChA referring the previous microsurgical descriptions.

METHODS

Ninety consecutive patients with isolated acute infarction in the PLIC were studied. We classified patients into 4 groups. 1. The anterior type that involved the anterior one-third part of the PLIC. 2. The posterior type that involved the caudal two-third part of the PLIC, 3. The combined type that located in the full length of the PLIC, 4. The dot type that restricted within PLIC up to10mm in diameter.

RESULTS

Patient numbers in groups 1 through 4 were 7 (7.7%), 46 (51.1%), 9 (10.6%) and 28 (31.1%). The anterior type involved the medial part of pallidum (MPP) in 5 patients (71.4%) and none in the lateral thalamus (LT), while the posterior type involved MPP only in 6 patients (13.0%) and LT in 33 patients (71.7%).

CONCLUSION

Corresponding to previous microsurgical descriptions, an occlusion of the proximal branches may cause anterior type infarct and that of the distal branches may cause posterior type infarcts. The anterior one third of the PLIC is also supplied by the branches of the AChA, albeit the low prevalence.

Intraoperative neuromonitoring during microsurgical clipping for unruptured anterior choroidal artery aneurysm

OBJECTIVE

To investigate the safety and unexpected finding of the intraoperative neuromonitoring (IONM) including somatosensory evoked potentials (SSEPs) and motor evoked potentials (MEPs) during microsurgical clipping of an unruptured anterior choroidal artery (AChA) aneurysm.

PATIENTS AND METHODS

From January 2011 to March 2018, the neurophysiological, clinical, and radiological data of 115 patients who underwent microsurgical clipping for an unruptured AChA aneurysm under IONM were retrospectively analyzed. The incidence of ischemic complications after microsurgical clipping of unruptured AChA aneurysms as well as the false-negative rate, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of IONM during surgery were calculated.

RESULTS

Ischemic complications after the microsurgical clipping of an AChA aneurysm under IONM occurred in 7 of 115 patients (6.08%). Among them, 3 were symptomatic (2.6%). The false-negative rate of IONM for ischemic complications was 6.08% (7 patients). High specificity; 100% (95% confidence interval [95% CI] = 0.972-1.000), PPVs; 100% (95% CI = 0.055-1.000), and NPVs; 93% (95% CI = 0.945-0.973) with low sensitivity; 11.1% (95% CI = 0.006-0.111) were calculated.

CONCLUSIONS

IONM including transcranial MEP during microsurgical clipping of unruptured AChA aneurysm might have limited usefulness. Therefore, other MEP monitoring using direct cortical stimulation or modified transcranial methodology should be considered to compensate for it.

Replaced posterior cerebral artery (PCA): origin of all branches of the PCA from the anterior choroidal artery diagnosed by MR angiography

We present a rare variant of the right posterior cerebral artery (PCA), recently named "replaced PCA," that demonstrates the origin of all its branches from the right anterior choroidal artery (AChA) on magnetic resonance (MR) angiography. In this variation, the right posterior communicating artery (PCoA) is hypoplastic and resembles the transposition of the AChA and PCoA. Detection of such rare arterial variations on MR angiographic images requires careful review of images, including source images, and partial maximum-intensity-projection images aid their identification.

Outcome Analysis of Surgical Clipping for Incidental Internal Carotid Posterior Communicating and Anterior Choroidal Artery Aneurysms

INTRODUCTION

Surgical outcome and ischemic complications of Internal carotid Posterior Communicating (IC PC) and anterior choroidal aneurysms have been questionable due to frequent occlusion of the anterior choroid artery and also due to low incidence of true anterior choroid artery aneurysms. The present series describes the postoperative outcome after clipping of such aneurysms at a single centre.

METHODS

A retrospective analysis of 73 cases with IC PC and Anterior choroidal aneurysms performed at a Fujita Health University, Banbuntane Hotokukai Hospital, Nagoya, Aichi, Japan from 2014 to 2018 have been studied and emphasis is made on the demography and ischemic complications.

RESULTS

A total of 73 patients with IC PC and anterior choroidal aneurysms were studied, out of which 57 patient had a true IC PC aneurysm, 14 patients had aneurysms involving the anterior choroidal artery and only 2 patients had aneurysms which involved both the IC PC and the anterior choroidal arteries. None of the patients had a permanent Anterior Choroidal Artery syndrome, whereas only 2 out of the 73 patients had postoperative complications in the form of transient hemiparesis.

CONCLUSION

Ischemic complications following surgical clipping of IC PC and anterior choroidal aneurysms can be minimised by meticulous micro dissection to identify the anterior choroidal artery thus preserving the patency of the same.

Microsurgical Treatment of Unruptured Anterior Choroidal Artery Aneurysms: Incidence of and Risk Factors for Procedure-Related Complications

OBJECTIVE

To describe our experiences with microsurgical treatment of unruptured anterior choroidal artery (AchA) aneurysms, and to evaluate the incidence of and risk factors for procedure-related complications.

METHODS

The study included 110 patients treated between January 2012 and December 2016. All patients met the following criteria: 1) microsurgical treatment of an unruptured AchA aneurysm was performed; and 2) clinical and radiographic follow-up data were available, including findings from preoperative digital subtraction angiography. The incidence of and risk factors for procedure-related complications were retrospectively evaluated. The χ² test and Mann-Whitney U test were used in statistical analysis, and univariate analysis and multivariate logistic regression analysis were conducted.

RESULTS

Procedure-related complications occurred in 5 patients (4.5%), including symptomatic complications in 4 patients (3.6%) and asymptomatic complications in 1 patient (0.9%). Multivariate logistic regression analysis indicated that the angle between the vertical line to the cranial base and the axis of the communicating segment of the internal carotid artery (MiC angle) (odds ratio [OR], 1.66; 95% confidence interval [CI], 1.13-5.26; P = 0.038) and the angle between the projection line of the aneurysmal dome and the axis of the communicating segment of the internal carotid artery (DC angle) (OR, 3.82; 95% CI, 1.49-11.7; P = 0.014) were independent risk factors for procedure-related complications.

CONCLUSIONS

When microsurgical treatment of unruptured AchA aneurysms was performed, the procedure-related complication rate was 4.5%. Patients with AchA aneurysms with a smaller MiC angle and smaller DC angle may be at a higher risk of procedure-related complications when undergoing microsurgical treatment.

Anterior Choroidal Artery Aneurysms: Influence of Regional Microsurgical Anatomy on Safety of Endovascular Treatment

Several anatomical variables critically influence therapeutic strategizing for anterior choroidal artery (AChA) aneurysms, and specifically, the safety of flow diversion for these lesions. We review the microsurgical anatomy of the AChA, discussing and detailing these considerations in the treatment of AChA aneurysms, theoretically and in the light of our recent findings.

Clinical importance of the anterior choroidal artery: a review of the literature

The anterior choroidal artery (AChA) is a critical artery in brain physiology and function. The AChA is involved in many diseases, including aneurysm, brain infarct, Moyamoya disease (MMD), brain tumor, arteriovenous malformation (AVM), etc. The AChA is vulnerable to damage during the treatment of these diseases and is thus a very important vessel. However, a comprehensive systematic review of the importance of the AChA is currently lacking. In this study, we used the PUBMED database to perform a literature review of the AChA to increase our understanding of its role in neurophysiology. Although the AChA is a small thin artery, it supplies an extremely important region of the brain. The AChA consists of cisternal and plexal segments, and the point of entry into the choroidal plexus is known as the plexal point. During treatment for aneurysms, tumors, AVM or AVF, the AChA cisternal segments should be preserved as a pathway to prevent the infarction of the AChA target region in the brain. In MMD, a dilated AChA provides collateral flow for posterior circulation. In brain infarcts, rapid treatment is necessary to prevent brain damage. In Parkinson disease (PD), the role of the AChA is unclear. In trauma, the AChA can tear and result in intracranial hematoma. In addition, both chronic and non-chronic branch vessel occlusions in the AChA are clinically silent and should not deter aneurysm treatment with flow diversion. Based on the data available, the AChA is a highly essential vessel.

Risks of Endoscopic Temporal Ventriculocisternostomy for Isolated Lateral Ventricle: Anatomic Surgical Nuances

BACKGROUND

Entrapment of the temporal horn, known as isolated lateral ventricle (ILV), is a rare type of noncommunicating focal hydrocephalus, and standard treatment has not been established. We report 2 cases of endoscopic surgery for ILV and highlight the anatomic surgical nuances to avoid associated surgical risks.

CASE DESCRIPTION

The first patient presented with recurrent ILV following initial shunt placement for ILV, owing to shunt malfunction. In the second patient, ILV recurred secondary to choroid plexus inflammation caused by cryptococcal infection. Endoscopic temporal ventriculocisternostomy was effective in both cases. However, in the second case, the choroidal fissure was fenestrated, which led to cerebral infarction in the territory of the choroidal artery zone, attributed to damage of the branches of the choroidal segment of the anterior choroidal artery.

CONCLUSIONS

Although endoscopic temporal ventriculocisternostomy is considered a safe and less invasive procedure for treatment of symptomatic ILV, the technique is still associated with risks. To avoid complications, it is necessary to be familiar with the anatomy of the choroidal arteries and the pertinent endoscopic intraventricular orientation. Additionally, sufficient experience is required before it can be recommended as the treatment of choice.

The cisternal segment of the anterior choroidal artery: an anatomical study using magnetic resonance imaging

PURPOSE

The topography of the anterior choroidal artery (AChA) has infrequently been delineated on neuroimages. The present study aimed to explore the cisternal segment of the AChA using magnetic resonance imaging.

METHODS

A total of 50 sides of the AChA obtained from 25 patients were included in this study. A constructive interference in steady-state (CISS) sequence was performed in thin-sliced axial sections. Furthermore, the cisternal AChA and relevant neurovascular structures were observed through cadaveric dissections in two heads.

RESULTS

In the cadaveric dissections, all the AChAs were exposed only in the proximal part even after extensive arachnoid dissections and cerebral retraction. In the examinations with the CISS sequence, the original site of the AChA was identified on the right side in 88% and on the left side in 96%. In 70% of the 50 sides, the AChA arose from the posterolateral wall of the internal carotid artery, distally to that of the posterior communicating artery. The cisternal course of the AChA was delineated on the right side in 96% and on the left side in 100%; it crossed over the optic tract in variable manners with the middle third as the most frequent site found in 60% of the sides.

CONCLUSIONS

The cisternal AChA shows a morphological variability. The CISS sequence is useful for delineating the cisternal AChA.

Complication Risk Factors in Anterior Choroidal Artery Aneurysm Treatment

OBJECT

The anterior choroidal artery (AChoA) is a rare location for intracranial aneurysms. The treatment of these aneurysms may be challenging due to the risk of occlusion of such a small and eloquent artery as the AChoA. We aimed to evaluate the risk factors for complications in AChoA aneurysm treatment.

METHODS

We retrospectively analyzed 47 consecutive AChoA aneurysms in 40 patients treated in our institution from 1999 and 2014 by endovascular means (87%) or surgical clipping (13%). Minor (transient or minor neurological deficits) and major complications (severe permanent neurological deficits or death) were systematically recorded. The influence of patient age, sex, aneurysm size, neck size, shape, dome-to-neck ratio and treatment technique on the occurrence of procedure-related complications was evaluated.

RESULTS

Of the patients 11 experienced procedure-related complications (5 major, 6 minor). Aneurysms with multilobed shape were significantly associated with a higher procedure-related complication rate. There was a tendency for higher major procedure-related complication rate in small volume aneurysms. We did not find any association between the other factors analyzed and occurrence of procedure-related complications.

CONCLUSION

Treatment of AChoA aneurysms has an acceptable complication risk. We did not find any significant differences between surgical and endovascular treatment in terms of procedure-related complication rates. Multilobed aneurysms were significantly associated with a higher procedure-related complication rate.

Usefulness of Motor-Evoked Potentials Monitoring for Neurosurgical Treatment of an Unusual Distal Anterior Choroidal Artery Aneurysm

A 35 years old woman presented with an acute meningeal syndrome following an intra ventricular haemorrhage without subarachnoid haemorrhage. The angiography demonstrated a 6 mm partially thrombosed saccular aneurysm at the plexal point of the right anterior choroidal artery (AChoA). It was surgically approached inside the ventricle through a trans-temporal corticotomy. The aneurysm was excised after distal exclusion of the feeding artery under motor-evoked potentials monitoring. Of the 19 cases of distal AChoA aneurysm neurosurgical treatment, this is the only one performed under electrophysiology monitoring, a simple and safe method to detect and prevent motor tract ischemia. We discuss this rare case, along with a comprehensible review of the literature of the previous surgical cases of distal AChoA aneurysms.

Pre-operative embolization of a choroid plexus carcinoma: review of the vascular anatomy

AIM

The purpose of this case is to highlight the benefits of preoperative embolization as well as to review the vascular anatomy that needs to be recognized in order to perform pre-operative embolization of choroid plexus tumors.

METHOD

We achieve this by presenting the case of a 12-month-old female who had symptoms of raised intracranial pressure. MRI demonstrated a large vividly enhancing mass centered within the atria of the right lateral ventricle associated with hydrocephalus in keeping with a choroid plexus tumor.

RESULT

Enlarged anterior and posterior choroidal arteries supplying the tumor were noted on the MRI scan. Pre-operative embolization was performed with NBCA glue via the anterior and posterior choroidal arteries. Subsequently, total surgical resection was achieved with only 200 cc of blood loss. Pathology confirmed a choroid plexus carcinoma.

CONCLUSION

Pre-operative embolization can be useful in minimizing blood loss during excision of choroid plexus tumors. It is important to understand the anatomy of the anterior and posterior choroidal arteries to perform embolization of these tumors safely.

Duplicated middle cerebral artery arising from the origin of the hyperplastic anterior choroidal artery that mimicked aneurysm on routine MR angiography

We report a case of duplicated right middle cerebral artery that arose from the origin of the right hyperplastic anterior choroidal artery diagnosed by magnetic resonance angiography. To our knowledge, this is the first case of such a variation reported with magnetic resonance angiographic images. The internal carotid artery-hyperplastic anterior choroidal artery-duplicated middle cerebral artery junction was dilated and mimicking aneurysm. Partial maximum intensity projection images and volume-rendering images showed that it was not a saccular aneurysm but an infundibular dilatation. Careful observation of magnetic resonance angiographic images including its source images is important for detecting rare arterial variations. To identify an anomalous artery on magnetic resonance angiography, creation of partial maximum intensity projection images and volume-rendering images is valuable.

An unusual, duplicate origin of the anterior choroidal artery with aneurysm: a case report

BACKGROUND AND IMPORTANCE

Aneurysms of the anterior choroidal artery (AChoA) are rare and often difficult to treat. Variations may be present and must be identified prior to treatment. We report a unique case of a ruptured aneurysm located at the origin of a duplicate branch of the AChoA.

CLINICAL PRESENTATION

A 56-year-old male was admitted to our university hospital for coma. A brain CT scan showed a subarachnoid hemorrhage, and CT angiography revealed a duplication of the right AChoA, with an aneurysm located at the branch's origin. We decided to embolize this aneurysm. Four weeks later, our patient was able to transfer to the rehabilitation unit.

CONCLUSION

To the best of our knowledge, this is one of the first descriptions of an aneurysm located at the origin of a duplicate branch of the AChoA.

Demonstration of traumatic subarachnoid hemorrhage from the anterior choroidal artery

We present a case of angiographically confirmed transection of the cisternal segment of the anterior choroidal artery (AChA) associated with a severe head trauma in a 15-year old boy. The initial brain computed tomography scan revealed a diffuse subarachnoid hemorrhage (SAH) and pneumocephalus with multiple skull fractures. Subsequent cerebral angiography clearly demonstrated a complete transection of the AChA at its origin with a massive extravasation of contrast medium as a jet trajectory creating a plume. We speculate that severe blunt traumatic force stretched and tore the left AChA between the internal carotid artery and the optic tract. In a simulation of the patient's brain using a fresh-frozen male cadaver, the AChA is shown to be vulnerable to stretching injury as the ipsilateral optic tract is retracted. We conclude that the arterial injury like an AChA rupture should be considered in the differential diagnosis of severe traumatic SAH.

Blood blister-like aneurysm with rupture point close to origin of anterior choroidal artery

If a ruptured blood blister-like aneurysm (BBA) arises from the lateral or superolateral wall of the internal carotid artery (ICA) at the level of the anterior choroidal artery (AChA), its proximity to the origin of the AChA presents a serious surgical challenge to preserve the patency of the AChA. Two such rare cases are presented, along with successful surgical techniques, including the application of a C-shaped aneurysm clip parallel to the ICA and a microsuture technique to repair the arterial defect. The patency of the AChA and ICA was successfully preserved without recurrence or rebleeding of the BBA during a 1-year follow-up after the operation.

Infarction in the anterior choroidal artery territory: clinical progression and prognosis factors

This study was undertaken to describe the still poorly known evolving profile of anterior choroidal artery (AChA) infarctions, identify their prognosis factors, and evaluate responses to intravenous (IV) thrombolysis. During 42 months, we prospectively enrolled patients with an isolated AChA stroke. Clinical and radiologic parameters were compared between patients with or without progression, defined as any clinical worsening. Factors associated with poor outcome (dependence or death) were tested, and IV thrombolysis responses were assessed. For the 100 of 1234 (8.1%) analyzed patients with AChA stroke (predominantly lacunar syndrome [88%]), mean admission and maximum National Institutes of Health Stroke Scale (NIHSS) scores were 4.4 and 5.2, respectively. Arterial hypertension (78%) and diabetes (30%) were the main vascular risk factors. Despite low 3-month mortality (3%), 26% of the patients were dependent; 46 patients with progressive stroke (over 56 ± 56 hours, 1.6 mean successive plateaus) had higher risks of dependence (P < .0001). An acute-phase NIHSS score of 6 or more significantly increased the risk of poor outcome (P < .0001). Maximum NIHSS score and progression were independently associated with poor outcome. Among 21 patients given IV thrombolysis, 12 AChA strokes continued to progress, leaving 8 disabled at 3 months. Almost half of AChA strokes progress during the first 2 to 3 days. Maximum acute-phase NIHSS scores and progression were independently associated with poor outcome, also strongly predicted by an NIHSS score of 6 or more at any time. Our unconvincing experience with IV thrombolysis means new therapeutic options and trials are needed, especially for patients with clinical progression and/or NIHSS score of 6 or more.

Thrombolytic therapy is an only determinant factor for stroke evolution in large anterior choroidal artery infarcts

BACKGROUND

Large anterior choroidal artery (AChA) infarcts are frequently associated with stroke evolution. This study aimed to investigate the major determinants for stroke evolution in patients with large AChA infarcts.

METHODS

We studied 118 consecutive adult patients with acute large AChA infarcts. The diagnosis was confirmed as abnormal hyperintensities in 3 or more rostracaudal magnetic resonance imaging slices (5 mm thickness) using diffusion-weighted imaging within typical AChA vascular regions. Stroke evolution was defined as neurologic deterioration with an increase in National Institutes of Health Stroke Scale (NIHSS) score by at least 4 or an increase of NIHSS score in motor function by at least 2 in 7 days after stroke onset.

RESULTS

Forty-seven (39.8%) patients developed stroke evolution. Thrombolytic therapy was inversely associated with the occurrence of stroke evolution (P = .004). Using multivariate analysis, thrombolytic therapy was the only protective determinant for stroke evolution (adjusted odds ratio, .08; 95% confidence interval, .01 to .67). Patients with large AChA infarcts receiving thrombolytic therapy had less unfavorable long-term functional outcome than those not receiving thrombolytic therapy (adjusted odds ratio, .11; 95% confidence interval, .02-.75).

CONCLUSIONS

Thrombolytic therapy is an only determinant factor for stroke evolution in large AChA infarcts, which reduced the risk of stroke evolution and improved functional outcome.

Anterior choroidal artery aneurysm surgery: ischemic complications and clinical outcomes revisited

Objective

Surgical results for anterior choroidal artery (AChA) aneurysms have previously been reported as unsatisfactory due to inadvertent occlusion of the AChA, while the low incidence of AChA aneurysms hampers the accumulation of surgical experience. The authors reviewed their related surgical experience to document the ischemic complications and surgical outcomes.

Methods

Identification of the AChA at its origin by rigorous visual scrutiny, careful microdissection, and meticulous clip placement to avoid the AChA origin are all crucial surgical maneuvers. A retrospective review of a surgical series of 62 consecutive cases of an AChA aneurysm between 2004 and 2012 was performed.

Results

All patients, except for five (8.1%) with a small residual neck, showed complete aneurysm obliteration in postoperative angiographic evaluations. There was no incidence of procedure-related permanent AChA syndrome or oculomotor nerve palsy, while three (4.8%) patients suffered from transient AChA syndrome. The clinical outcomes [the 3-month modified Rankin Scale (mRS)] of the patients were related to their preoperative World Federation of Neurologic Surgeons (WFNS) grade. As regards the 3-month mRS, significant differences were found between patients with an unruptured aneurysm (WFNS grade 0; n=20), good-grade subarachnoid hemorrhage (WFNS grade 1-3; n=30), and poor-grade subarachnoid hemorrhage (WFNS grade 4-5; n=4).

Conclusion

In surgical treatment of AChA aneurysms, a risk of AChA insufficiency can be minimized by taking every precaution to preserve the AChA patency and intraoperative monitoring. In addition, the surgical outcome is primarily determined by the preoperative clinical state.

Transposition of anterior choroidal artery and posterior communicating artery origin

The anterior choroidal artery has several kinds of variations. Among them, the transposition of anterior choroidal artery and posterior communicating artery origins has been extremely rare. We report a case with cerebral aneurysm arising from posterior communicating artery which origin was distal to the anterior choroidal artery and review the relevant literature.