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Balloon test occlusion (BTO) can predict the ischemic complication risk associated with arterial occlusion. We present a case of an unruptured, broad-necked internal carotid artery-posterior communicating artery (PcomA) aneurysm that was successfully embolized after super-selective BTO of fetal PcomA with electrophysiological monitoring. The proximal portion of the PcomA was internally occluded without causing major neurological deficits, although we observed a small new infarction in the ipsilateral anterior thalamus postoperatively. We recognized small perforators arising from the proximal PcomA during a previous clipping surgery. Super-selective BTO with electrophysiological monitoring could be useful for functional preservation after infarction from angiographically invisible perforators.

Background Anterior communicating artery aneurysms are the second most common type of intracranial aneurysm and have a high incidence of rupture. Intraprocedural rupture can lead to a high mortality and morbidity rate, representing a major challenge in emergency endovascular treatment of ruptured anterior communicating artery aneurysms. Methods We performed a retrospective review of 344 consecutive patients with emergency endovascular treatment of ruptured anterior communicating artery aneurysms. Patients were grouped into intraprocedural rupture and non-intraprocedural rupture groups according to whether intraprocedural rupture occurred. Demographic and clinical factors, vessel-related factors and therapy-related factors were compared between the two groups. Results Intraprocedural rupture occurred in 11 patients (3.2%). Univariate analysis showed that hypertension, the occurrence of vasospasm, aneurysm size, aneurysm angle and a high aspect ratio value were significantly associated with intraprocedural rupture ( P Conclusions A history of hypertension, the occurrence of vasospasm and a high aspect ratio value are independent risk factors for intraprocedural rupture among patients with ruptured anterior communicating artery aneurysms.

Purpose: The purpose of this study was to evaluate the prevalence and risk factors of unruptured intracranial aneurysms (UIAs), which can help establish guidelines of treatment for asymptomatic Korean adults using 3T magnetic resonance angiography (MRA).Materials and Methods: Our Institutional Review Board approved this retrospective study, and informed consent was waived. All patients consisted of healthy individuals who underwent brain MRA using 3T magnetic resonance imaging between January 2011 and December 2012 as part of a routine health examination. Patient data and follow-up results were obtained from medical records.Results: A total of 2,118 individuals (mean age=53.9±9.6 years, male:female=1,188:930) who had undergone brain MRA were enrolled in the study. UIAs were found in 80 patients with 105 UIAs (3.77%). Female predominance (55% in UIA versus 43.47% in non-UIA, P=0.0416) and hypertension were more common in the UIA group (43.75% vs. 28.8%, P=0.004, respectively). The mean size of the aneurysms was 3.10±1.62 mm, and they were all saccular in shape and asymptomatic. The UIAs were most common in the internal carotid artery (59.1%), internal carotid-posterior communicating artery (15.2%), middle cerebral artery (9.5%), anterior communicating artery (8.6%), anterior cerebral artery (4.8%), and vertebral artery (2.9%). Twenty-eight of 80 patients (35%) had multiple aneurysms. The incidence of UIAs increased significantly with age (P=0.014).Conclusion: In single center experience, we demonstrated the characteristics and prevalence of UIAs in asymptomatic adults, which may help establish guidelines or therapeutic standards for UIAs.

The anterior and posterior communicating arteries are natural connections between arteries that enable different adjacent circulations to redistribute blood flow instantly in response to changing supply and demand. An analogous communication does not exist in the middle cerebral circulation. A middle communicating artery (MCoA) can be created microsurgically between separate middle cerebral artery (MCA) trunks, enabling flow to redistribute in response to changing supply and demand. The MCoA would draw blood flow from an adjacent circulation such as the external carotid circulation. The MCoA requires the application of fourth-generation techniques to reconstruct bi- and trifurcations after occluding complex MCA trunk aneurysms. In this report, the authors describe two recent cases of complex MCA bi- and trifurcation aneurysms in which the occluded efferent trunks were revascularized by creating an MCoA. The first MCoA was created with a “double-barrel” superficial temporal artery–M2 segment bypass and end-to-end reimplantation of the middle and inferior MCA trunks. The second MCoA was created with an external carotid artery–radial artery graft–M2 segment interpositional bypass and end-to-side reimplantation of the inferior trunk onto the superior trunk. Both aneurysms were occluded, and both patients experienced good outcomes. This report introduces the concept of the MCoA and demonstrates two variations. Angioarchitectural and technical elements include the donation of flow from an adjacent circulation, a communicating bypass, the application of fourth-generation bypass techniques, and a minimized ischemia time. The MCoA construct is ideally suited for rebuilding bi- and trifurcated anatomy after trapping or distally occluding complex MCA aneurysms.

Background Posterior communicating (Pcom) aneurysms in the modern era have tended toward increased complexity and technical difficulties. The pretemporal approach is a valuable extension to the pterional approach for basilar apex aneurysms, but its advantages for Pcom aneurysms have not been previously elucidated. Objective To quantify characteristics of the pretemporal approach to the Pcom. Methods We dissected 6 cadaveric heads (12 sides) with a pretemporal transclinoidal approach and measured the following variables: (1) exposed length of internal carotid artery (ICA) proximal to the Pcom artery; (2) exposed circumference of ICA at the origin of Pcom; (3) deep working area between the optic nerve and tentorium/oculomotor nerve; (4) superficial working area; (5) exposure depth; and (6) the frontotemporal (superior posterolateral) and (7) orbito-sphenoidal (inferior anterolateral) angles of exposure. Results Compared with pterional craniotomy, the pretemporal transclinoidal approach increased the exposed length of the proximal ICA from 3.3 to 11.7 mm (P = .0001) and its circumference from 5.1 to 7.8 mm (P = .0003), allowing a 210° view of the ICA (vs 137.9°). The deep and superficial working areas also significantly widened from 53.7 to 92.4 mm2 (P = .0048) and 252.8 to 418.2 mm2 (P = .0001), respectively; the depth of the exposure was equivalent. The frontotemporal and spheno-Sylvian angles increased by 17° (P = .0006) and 10° (P = .0037), respectively. Conclusion The pretemporal approach can be useful for complex Pcom aneurysms by providing easier proximal control, wider working space, improved aneurysm visualization, and more versatile clipping angles. Enhanced exposure results in a potentially higher rate of complete aneurysm obliteration and complication avoidance.

Background With advances in endovascular techniques, the relative roles of microsurgery and endovascular therapy in the management of intracranial aneurysms have become less clear, and data regarding treatment-specific outcomes are increasingly important. Objective To describe our experience with microsurgery in a large series of unruptured anterior communicating artery aneurysms (ACOMMAAs) and detail our treatment decision-making process based on individual aneurysm morphology. Methods We retrospectively reviewed unruptured ACOMMAAs treated microsurgically at our center between 1997 and 2018, recording aneurysm size, surgical approach, occlusion rates, neurological outcomes, and complications. Results We treated 300 unruptured ACOMMAAs in 300 patients, mean age 49 yr, 180 (60.0%) female, including 245 (81.7%) small, 50 (16.7%) large, and 5 (1.7%) giant aneurysms. Most underwent a pterional approach (253, 84.3%), with orbitozygomatic or anterior interhemispheric approaches in 35 (11.7%) and 12 (4%), respectively. Greater than 95% occlusion was achieved in 284 (94.7%), 90% to 95% occlusion in 13 (4.3%), and 3 (1.0%) underwent wrapping. Serious complications occurred in 3 patients (1.0%) resulting in 2 deaths (0.7%), and minor complications in 12 (4.0%). At final follow-up, good neurological outcome was observed in 297 (99.0%) patients. Conclusion Given clinical equipoise regarding optimal treatment of unruptured ACOMMAAs, this work provides a benchmark for achievable microsurgical outcomes. Future surgical/endovascular studies should separate results of ruptured and unruptured lesions and describe aneurysm morphology to allow for better comparison of outcomes between treatments. We suggest that open microsurgery represents an important option for select, morphologically complex ACOMMAAs, and that a multidisciplinary approach offers optimal patient outcomes.

Background The use of bypass surgery for anterior communicating artery (ACOM) aneurysms is technically challenging. Communicating bypass (COMB), such as pericallosal artery side-to-side anastomosis, is the most frequently used and anatomically directed reconstruction option. However, in many complex cases, this technique may not afford a sufficient blood supply or necessitate sacrificing the ACOM and the eloquent perforators arising from it. Objective To evaluate tailored COMB and propose a practical algorithm for the management of complex ACOM aneurysms. Methods For 1 patient with an aneurysm incorporating the entire ACOM, conventional in Situ A3-A3 bypass was performed as the sole treatment in order to create competing flow for aneurysm obliteration, sparing the sacrifice of eloquent perforators. In situations in which A2s were asymmetric in the other case, the contralateral A2 orifice was selected as the donor site to provide adequate blood flow by employing a short segment of the interposition graft. Results The aneurysm was not visualized in patients with in Situ A3-A3 bypass because of the "flow-counteraction" strategy. The second patient, who underwent implementation of the contralateral A2 orifice for ipsilateral A3 interposition bypass, demonstrated sufficient bypass patency and complete obliteration of the aneurysm. Conclusion The feasibility of conventional COMB combined with complete trapping may only be constrained to selected ideal cases for the treatment of complex ACOM aneurysms. Innovative modifications should be designed in order to create individualized strategies for each patient because of the complexity of hemodynamics and the vascular architecture. Flow-counteraction in Situ bypass and interposition bypass using the contralateral A2 orifice as the donor site are 2 novel modalities for optimizing the advantages and broadening the applications of COMB for the treatment of complex ACOM aneurysms.

Background: The reconstruction of distal foot for various defects or contractures mainly over or near the toes has always been a diffi cult task. A fl ap distally based on fi rst web space is dependent upon a perforator arising from the the distal communicating artery between the fi rst dorsal and plantar metatarsal arteries, can be used for the coverage of the toe or the distal foot defects.

Anterior communicating artery (A.com.A) aneurysm projection is an important factor in determining the outcome of aneurysm clipping. The objective of this study was to analyze the outcome of A.com.A aneurysm projection and prognostic factors influencing it and comparing them with Glasgow outcome scale. A retrospective analysis of 47 patients from hospital records who have got admitted in the Banbuntanke Hotokokai Hospital, Nagoya, Japan, from 2014 to 2017, with unruptured A.com.A aneurysm and subsequently operated in the hospital. Demographic factors such as age, sex, and associated with other aneurysms and the morphological characteristics such as aneurysm size, projection, and height were analyzed with postoperative complications and Glasgow outcome scale. Totally 47 cases have been operated in which 26 (55.3%) are female and 21 (44.6%) are male, and the median age is 68 years, 7 (14.89%) patients had middle cerebral artery aneurysm along with A.com.A aneurysm and 1 had internal carotid artery-posterior communicating artery junction aneurysm. Four (8.5%) had chronic subdural hematoma and 1 (2.12%) had epilepsy, 1 (2.12%) case got reoperated, and 1 (2.12%) had hydrocephalus. Moreover, the overall complication rate is 14.89%. For six patients, motor-evoked potential monitoring was used. Forty-six patients had Glasgow outcome scale of 5 and 1 patient had Glasgow outcome scale of 4. There was no mortality in this study. Mean size of the aneurysm was 6.68 mm and the range was 2–25 mm. Mean height was 4.14 mm, 26 (56.52%) A.com.A aneurysm were anteriorly projecting, 9 (19.56%) were superiorly projecting, 8 (17.32%) were inferiorly projecting, and 3 (6.38%) were posteriorly projecting. Morphological parameters such as size, height, and projection were not only highly associated with A.com.A aneurysm rupture and also complications due to clipping of aneurysm.

With the development of radiography, especially digital subtraction cerebrovascular angiography, which is widely used in clinical practice, interventional embolization of intracranial aneurysms has become more and more popular due to its advantages of minimal invasiveness, high efficiency, and rapid postoperative recovery. The choice of patients, often we have to formulate an unconventional and individualized treatment plan based on the specific conditions of each patient’s blood vessel. This case is a segment A1 aneurysm of the right anterior cerebral artery. Due to its special location and wide diameter, in order to reduce the difficulty and risk of the operation during the operation, a bilateral internal carotid artery approach was developed to complete the stent-assisted procedure and special treatment plan for aneurysm embolization.

The Woven EndoBridge (WEB) device (MicroVention, Aliso Viejo, California) is an intrasaccular flow disruptor used for the treatment of both unruptured and ruptured intracranial aneurysms. WEB has been shown to have 54% complete and 85% adequate aneurysm occlusion rates at 1-yr follow-up.1 Residual and recurrent ruptured aneurysms have been shown to have a higher risk of re-rupture than completely occluded aneurysms.2 With increased utilization of WEB in the United States, optimizing treatment strategies of residual aneurysms previously treated with the WEB device is essential, including surgical clipping.3,4 Here, we present an operative video demonstrating the surgical clip occlusion of previously ruptured middle cerebral artery and anterior communicating artery aneurysms that had been treated with the WEB device and had sizable recurrence on follow-up angiography. Informed consent was obtained from both patients. Lessons learned include the following: (1) the WEB device is highly compressible, unlike coils; (2) proximal WEB marker may interfere with clip closure; (3) no evidence of WEB extrusion into the subarachnoid space; (4) no more scarring than expected in ruptured cases; and (5) clipping is a feasible option for treating WEB recurrent or residual aneurysms.

This case of endoscopic third ventriculostomy (ETV) and flexible endoscopy for lysis of fourth ventricle adhesions for obstructive hydrocephalus illustrates a key anatomical variant (anastomosis of posterior communicating arteries) that increases the difficulty of ETV and should be recognized preoperatively. The video further demonstrates flexible endoscopy for lysis of a fourth ventricular web and excellent third and fourth ventricular anatomy. This patient presented with normal pressure hydrocephalus-like symptoms and magnetic resonance imaging suggestive of a fourth ventricular outflow obstruction. An ETV would be an ideal intervention with a high chance of success1 and avoiding a ventriculoperitoneal shunt or a more invasive suboccipital craniectomy for fourth ventricle exploration; however, variant anatomy and resultant medialization of the bilateral posterior communicating arteries put their location directly beneath the tuber cinereum. After discussing the risks and benefits of the proposed procedure, the patient consented to proceeding with the surgery. Patient is not identifiable either by clinical vignette or through this operative video, which is entirely intraventricular. The care rendered was standard (nonexperimental). The patient did sign consent for filming and production of the educational video submitted. Here, we present operative video from our ETV, demonstrating an inability to confirm adequate fenestration and subsequent flexible endoscopy for fourth ventriculocisternostomy.

Objective: In Japan, hybrid neurosurgeons who perform both open surgical clipping as well as endovascular embolization for the treatment of intracranial aneurysms are common. Although many Japanese neurosurgeons can perform surgical clipping of middle cerebral artery aneurysms or internal carotid artery—posterior communicating artery aneurysms and coil embolization of cerebral aneurysms using simple techniques—only a limited number of neurosurgeons are able to perform surgical clipping and endovascular procedures for anterior communicating artery aneurysms, paraclinoid, or posterior circulation aneurysms using both treatment modalities equally and safely. Materials and methods: The senior author’s personal experience of more than 500 cases each of surgical clipping and endovascular embolization over the past 25 years included 110 cases of basilar tip aneurysms and 104 cases of paraclinoid internal carotid artery (ICA) aneurysms. Results: The safety and efficacy of both treatments appears to be the same, while the durability of surgical clipping is superior to that of endovascular embolization. Among the 110 basilar tip aneurysms, 18 patients were treated by surgical clipping and 94 were treated by endovascular embolization. The initial results of endovascular therapy seemed to be better than those of surgical clipping, although the rate of retreatment was higher. Among the 104 cases of paraclinoid ICA aneurysm, 23 patients were treated by surgical clipping and 81 were treated by endovascular embolization. The results of both treatments seemed to be same, while surgical clipping had apparently good long-term durability. Over the past 15 years, the frequency of surgical clipping for basilar tip aneurysms has decreased, and the procedure may eventually be abandoned for this type of aneurysm. However, surgical clipping still offers several advantages in the treatment of paraclinoid aneurysms. Conclusions: Hybrid neurosurgeons can make reasonable decisions concerning the choice of treatment for cerebral aneurysms, as they perform both treatments and understand the benefits and drawbacks of each modality.

Acute carotid terminus occlusion (CTO) is responsible for up to 5% of acute ischemic strokes secondary to emergent large vessel occlusion (ELVO) and up to 20% of acute internal carotid artery (ICA) occlusions.1 The term "CTO" has also been used to describe occlusions in the supra-clinoid segment or at the bifurcation of the ICA. Compared to other ELVOs, patients with CTO present with higher stroke severity and larger infarct volume, likely to be a result of disruption of direct Circle of Willis collaterals across the anterior communicating artery (AComA) and posterior communicating artery (PComA).2,3 Similary, CTO is usually associated with worse prognosis compared to other ELVOs in general. With regard to response to treatment, previous studies have reported significantly lower recanalization rates with intravenous alteplase with CTO compared to M1 segment occlusion. With regard to the safety and efficacy of mechanical thrombectomy, prior reports provide conflicting results with some reporting lower successful recanalization rates with CTO compared to M1 occlusion, and others reporting similar results. In our experience, we have found that successful recanalization of CTO can be achieved with a similar approach to M1 occlusions utilizing a direct aspiration first pass technique (ADAPT).3,4 Herein, we present a case of CTO for which we performed mechanical thrombectomy using ADAPT. This procedure was an emergent standard of care procedure for which a consent was not required and so not obtained.

Introduction : Intracranial aneurysms (IA) is an acquired disease characterized by dilatation of intracranial arteries, and is usually found at the location of arterial branches in the cranii base region. The selection of management and anatomic variations is quite interesting to be discussed in the case of aneurysms. Cases Report : Four cases of AcoA aneurysm were reported with variations in clinical manifestations, A1 segment anatomy, fundal projections and management considerations (Coiling vs. Clipping). This case series illustrates the compatibility with previous case studies that have existed. Discussion : The author concludes that the actions taken in cases I, II and III are in the form of coiling due to age, dome and neck ratio and access to perform such difficult surgical procedures. In case IV , it was considered to be performed surgical clipping action due to the presence of intracerebal hemoraghic, and the approach can be done from a non dominant hemisphere, proximal control only through the right carotid and the location of the posterior dome which was favorable for surgical clipping Conclusion : Aneurysms from the ACA-anterior communicating artery (ACoA) complex are some of the most complex lesions in the field of vascular neurosurgery. This location is where most rupture aneurysms occured with high mortalities due to complications of vasospasm and SAH. The choice of management in aneurysm cases which involved many factors such as age and anatomic variations.

Unilateral oculomotor nerve palsy, often caused by aneurysmal compression, is one of the decisive findings for confirming the site of a ruptured aneurysm. However, arterial compression can also cause unilateral oculomotor nerve palsy. Here, we present the case of a 59-year-old woman with a ruptured right internal carotid-posterior communicating artery aneurysm accompanied by contralateral oculomotor nerve palsy. The nerve was found to be compressed by the posterior cerebral artery and was isolated from the ruptured aneurysm. When confirming a ruptured aneurysm based on the evidence of unilateral oculomotor palsy, the arteries surrounding the nerve must be thoroughly assessed.

A 65-year-old male received coil embolization for a large internal carotid-posterior communicating artery aneurysm. Pre- and postoperative angiography at surgery demonstrated that the ipsilateral anterior choroidal artery branched from the internal carotid artery near the distal side of the aneurysm, and elevated and expanded on the aneurysmal dome, but was clearly visualized. Three days following endovascular treatment, the patient presented hemiparesis on the left side, with brain infarction in the territory of the right anterior choroidal artery despite antithrombotic therapy. The delayed brain infarction was likely caused by a reduction in anterior choroidal artery perfusion caused by mechanical compression following a postoperative increase in internal carotid-posterior communicating artery aneurysmal volume during intra-aneurysmal thrombosis. Transient volume expansion after coil embolization for intracranial aneurysms is rarely reported as a cause of brain infarction. It is important to recognize these arteries as potential postoperative complication risks, and consider the use of open surgery to avoid this risk.

This report presents a rare case of such an aneurysm arising from such a communicating artery. A 66-year-old woman presented with a subarachnoid hemorrhage located predominantly in the cisterna magna with intraventricular hemorrhage. Angiography showed hypoplasia of the right posterior inferior cerebellar artery. Its vermian territory was supplied by the communicating artery from the posterior medullary segments of the left posterior inferior cerebellar artery. An aneurysm was on that communicating artery itself at a nonbranching site. The aneurysm was trapped the next day. Postoperative computed tomography showed no infarct in the right posterior inferior cerebellar artery territory. Trapping is applicable when other collateral vessels supply the contralateral posterior inferior cerebellar artery territory. J. Med. Invest. 67 : 197-199, February, 2020.

A 59-year-old female presented with severe headache and trouble of consciousness. The CT showed a subarachnoid hemorrhage FISHER IV with a hematoma of the right cerebellum. The angiography discovered a persistent left trigeminal artery associated with an aneurysm of the right posterior meningeal artery. The attempt of embolization failed and the patient suffered cerebral vasospasm and died. The persistence of a trigeminal artery is found in 0.1–0.6% of the population. It is the most frequent embryological carotid-vertebral anastomosis. It appears at the fifth week of development and disappears when the embryo reaches 5–7 mm. This embryological persistence is associated with numerous vascular abnormalities. The literature review showed the presence of those aneurysms in the trigeminal artery itself or the communicating artery. The association that we described is the first to our knowledge. Therefore, this association is particular and interesting to expose.

Large dolichoectatic aneurysms of middle cerebral artery (MCA) trifurcations are rare and often require trapping and revascularization of the region with a bypass.1-9 This video describes the treatment of an MCA trifurcation aneurysm by clip trapping and double-barrel superficial temporal artery (STA) to M2-MCA bypass followed by M2-M2 end-to-end reimplantation to create a middle communicating artery (MCoA). The patient, a 60-yr-old woman, presented with headache, a history of smoking, and a family history of ruptured aneurysms. Angiography demonstrated a 1.7-cm dolichoectatic aneurysm of the MCA trifurcation. While the natural history of these lesions is unclear, the aneurysm size and family history of aneurysmal subarachnoid hemorrhage were factors in proceeding with treatment. Informed written consent was obtained from the patient and her family. The STA branches were harvested microsurgically, a pterional craniotomy was performed, and the aneurysm was exposed through a transsylvian approach. The two STA branches were anastomosed end-to-side to the middle and inferior trunks of the MCA. Due to the significant mismatch between the donor and recipient vessel calibers, we were concerned that the donors might provide insufficient flow in isolation. Therefore, we decided to transect both M2 trunks from the aneurysm, proximal to the inflow of the bypass, and reimplant them end-to-end. This reimplantation created an MCoA, allowing the two donor arteries to supply the new communication between the inferior and middle trunks, redistributing blood flow through the MCoA according to cerebral demand. Bypass patency and aneurysm obliteration were confirmed on postoperative angiography. At the 6-mo follow-up, the patient's modified Rankin Scale (mRS) score was 0. The MCoA is a novel construct that, like natural communicating arteries, redistributes flow in response to shifting demand, without the need for additional ischemia time during the bypass. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

Dolichoectatic aneurysms of the middle cerebral artery (MCA) bifurcation pose unique treatment challenges.1 One treatment consists of an extracranial-intracranial (EC-IC) interpositional bypass and double-reimplantation of the M2 divisions.2-8 We present a variation of this construct in which an M2 MCA-M2 MCA end-to-side reimplantation was performed, creating a middle communicating artery (MCoA). The patient, a 61-yr-old woman, had previously undergone a "picket fence" clip reconstruction of an unruptured, giant left MCA bifurcation aneurysm in 2014.9 After the patient provided informed written consent for treatment, a 5-yr surveillance angiogram revealed substantial aneurysm regrowth opposite the clips. A pterional craniotomy was performed, and the aneurysm was exposed through a transsylvian approach. Proximal external carotid artery-radial artery graft (ECA-RAG) anastomosis was performed to arterialize the graft. The distal RAG was anastomosed end-to-side to the temporal division of the M2 segment, and the vessel proximal to the bypass inflow was transected from the aneurysm. We repurposed this "dead-end" as an MCoA by end-to-side reimplantation onto a branch of the frontal M2 trunk. The superior trunk was then clip occluded at its origin at the aneurysm. The aneurysm could not be proximally occluded due to lenticulostriate arteries arising from the back of the bifurcation. Postoperative angiography confirmed patency of the MCoA and its donor bypasses. The aneurysm no longer filled, and the lenticulostriate arteries were preserved. The patient was discharged on postoperative day 3 and made an excellent recovery (3-mo modified Rankin Scale [mRS] = 1). The MCoA is a novel construct that redistributed flow from the interpositional graft into the superior trunk, without the need for additional ischemia time while working with the inferior trunk. Used with permission from Barrow Neurological Institute.

Background Suprachiasmatic subcallosal lesions may have an intimate relationship with the anterior communicating artery (AcomA); injury to AcomA branches can result in basal forebrain infarction and cognitive dysfunction. Objective To evaluate anatomic variations of the AcomA basal perforating branches, especially the subcallosal artery (ScA), for clinical implications when approaching the suprachiasmatic subcallosal region from endonasal and transcranial routes. Methods The origin, course, diameter, and branching pattern of the AcomA's perforating branches were studied in 33 specimens from transcranial and endonasal perspectives. Results The ScA was present in 79% of the specimens as a single dominant artery arising from the posterior/posterosuperior surface of the AcomA, along with hypothalamic arteries (55%), or as a single artery (24%). It coursed posteriorly towards the lamina terminalis region, curving superiorly to the subcallosal area. The ScA gave off many branches to provide the main blood supply to the subcallosal region. Importantly, it supplies the septal/subcallosal region bilaterally. The ScA can be found posterior, superior, or inferior to the AcomA when using a transylvian, interhemispheric, or endonasal approach, respectively. In specimens with no ScA (21%), the median callosal artery (MdCA) was the dominant artery arising from the AcomA. It followed an identical course to the ScA, providing supply to the same structures bilaterally, but its distal extension reached the body/splenium of the corpus callosum. The MdCA is a ScA variant. Conclusion The ScA is a unique vessel because it supplies the septal/subcallosal region bilaterally; preservation of this vessel during surgery is crucial for successful outcomes.

This article presents the results of analysis of the arterial vascular region of the Eurasian elk, which is a representative of the Cervidae family. The study was conducted on 39 Eurasian elks. The head arteries of 25 animals were filled with LBS 3040 synthetic latex. The head arteries of the other 14 Eurasian elks were filled with an acetone solution of stained chlorinated polyvinyl chloride and macerated. The arterial circle of the Eurasian elk's brain is composed of bilateral rostral cerebral arteries and caudal communicating arteries. The basilar artery closes the arterial circle caudally. The rostral cerebral artery first ramifies into the rostral choroidal artery, then, the middle cerebral artery and the rostral communicating artery. The caudal cerebral artery and the rostral cerebellar artery branch off the caudal communicating artery. The arterial pattern of the Eurasian elk's brain base is similar to the arteries found in other deer. Like in other Ruminantia, the rostral epidural rete mirabile is a unique structure in the Eurasian elk's arterial system. Anat Rec, 302:339-345, 2019. © 2018 Wiley Periodicals, Inc.

Background: “Remote aspiration,” using suction from the proximal internal carotid artery (ICA) to open terminus occlusions, has been reported in small case series. However, it remains unclear whether remote aspiration is feasible for middle cerebral artery occlusions in the setting of potential inflow from communicating arteries. We performed an in vitro study to assess whether suction applied at various locations proximal to an occlusion could successfully aspirate the clot. Methods: A glass model of 4 mm inner diameter (ID) with 1 mm distal narrowing and 2 mm side branch to simulate a communicating artery was constructed. A proximal side branch was placed to simulate inflow from the proximal ICA. The impact of three different-sized catheters (ID 0.088, 0.070, and 0.056 in) on histologically different (red blood cell-cell rich, fibrin-rich, and mixed) clot analogues was tested with the catheter tip placed remotely either distal or proximal to the collateral branch. Aspiration was attempted with (1) open system (flow in both the ICA and the collateral branch, (2) flow arrest with open collateral (no flow in the ICA, but flow in the collateral branch), and (3) closed system (no flow in either the ICA or the collateral branch). The outcome was success or failure of remote aspiration. Results: For the 0.088-in catheter, remote aspiration was successful in all conditions. For the 0.070-in catheter, remote aspiration was unsuccessful without proximal flow arrest, but was successful in all other scenarios. For the 0.056-in catheter, remote aspiration was successful only with complete flow arrest. Conclusions: In a noncollapsible system, remote aspiration can be successfully achieved even in the setting of prominent branch arteries by using relatively large aspiration catheters. Proximal flow arrest may facilitate successful remote aspiration for some catheter sizes.

BACKGROUND Fetal-type posterior cerebral arteries (F-PCAs) might result in alterations in hemodynamic flow patterns and may predispose an individual to an increased risk of posterior communicating artery aneurysms (PCoAAs). OBJECTIVE To determine the association between PCoAAs and the presence of ipsilateral F-PCAs. METHODS We retrospectively reviewed the radiographic findings from 185 patients harboring 199 PCoAAs that were treated at our institution between 2005 and 2015. Our study population consisted of 4 cohorts: (A) patients with 171 internal carotid arteries (ICAs) harboring unilateral PCoAAs; (B) 171 unaffected ICAs in the same patients from the first group; (C) 28 ICAs of 14 patients with bilateral PCoAAs; and (D) 180 ICAs of 90 patients with aneurysms in other locations. We then determined the presence of ipsilateral F-PCAs and recorded all aneurysm characteristics. RESULTS Group A had the highest prevalence of F-PCAs (42%) compared to 19% in group B, 3% in group C, and 14% in group D (odds ratio A : B = 3.041; A : C = 19.626; and A : D = 4.308; P

Introduction: The authors present the analysis of the microsurgical clipping of 100 cerebral aneurysms of the anterior circulation and compare the series data with the literature. Methods: Eighty-eight patients presenting with 100 anterior circulation aneurysms operated on microsurgical techniques between 2002 and 2008 by the first author (CES) were retrospectively reviewed. Results: A total of 88 patients with 100 aneurysms of the anterior circulation were treated in a six years period. Fifty eight female (66%) and thirty male (34%) with nine patients (10.2%) presenting with multiple aneurysms. The mean age was 52 years (range from 26 to 76 years). Eighty five percent of the cases were ruptured aneurysms. The mean follow-up was 52.4 months (range from 5 to 76 months). The topography of the aneurysms was distributed as it follows: Anterior communicating artery (ACoA) 25%; posterior communicating artery (p-comm) 29%; middle cerebral artery (MCA) 27%; paraclinoidal aneurysms 8%; pericallosal artery 6% and internal carotid artery (ICA) tip 5%. The mortality was 7.9%, and such cases presenting with Hunt Hess graduation 3 and 4. The permanent morbidity was 4.5%, cases with Hunt Hess graduation 3 and 4. Perioperative rupture occurred in 17% of the cases, only in previous ruptured aneurysms. There was no clinical evidence of rebleeding during the follow-up period of the series. Conclusions: The microsurgical clipping of cerebral aneurysms of the anterior circulation is a safe and curative treatment for most of such lesions. At present, studies suggest evidences of superior results of surgery compared to the endovascular techniques in the rates of total occlusion of the aneurysms, lesser rates of rebleeding of the treated cases. The results of the present series are similar to the rates of the most relevant literature.

To present a unique case of the internal carotid artery-posterior communicating artery (ICA-PcomA) aneurysm penetrating the oculomotor nerve presenting a pure acute subdural hematoma (ASDH) without any oculomotor dysfunction. A 71-year-old woman presented with a sudden headache and drowsiness. She had no history of head trauma and did not manifest any neurological deficits including oculomotor nerve palsy. Computed tomography (CT) of her head revealed left ASDH. Subsequent CT angiography showed an aneurysm originating from the left ICA with an inferior projection having continuity with the hematoma. Intraoperative inspection revealed ASDH observed mainly in middle fossa and no subarachnoid hemorrhage, while the aneurysm was confirmed to split the oculomotor nerve and to be fixed with the middle fossa. The aneurysm was obliterated by direct clip application and the patient’s postoperative course was uneventful. Oculomotor nerve palsy is an important warning sign of imminent rupture of ICA-PcomA aneurysm. However, we should consider that the ICA-PcomA aneurysm could rupture causing ASDH without any oculomotor nerve palsy, even though the aneurysm penetrated the oculomotor nerve.

A low-lying internal carotid artery (ICA) running closer to the skull base than in usual cases prevents use of the standard transsylvian approach (TSA) to view an aneurysm through the retrocarotid space. A 75-year-old male had a 10-day history of headache and left eyelid ptosis. Initial computed tomography (CT) showed no evidence of subarachnoid hemorrhage. Emergency three-dimensional CT angiography showed a saccular aneurysm with bleb arising from the left horizontally projecting ICA. The aneurysm was approached through the TSA but could not be visualized well. We used the anterior temporal approach (ATA) followed by the TSA, offering a more lateral line of vision and allowing the surgeon to visualize the aneurysmal neck. The aneurysm was successfully obliterated. The ATA provided a better lateral view than the standard TSA for the ICA aneurysm. We emphasize the effectiveness of ATA for aneurysm arising from a low-lying IC-posterior communicating artery bifurcation.

Anatomic variations of the anterior cerebral artery-anterior communicating artery complex (ACA-AComA) are common. An infra-optic course of the A1-ACA is extremely rare, and recognition of this variant is very important in planning surgery for ACA-AComA complex aneurysms. We present two cases of spontaneous subarachnoid hemorrhage due to ruptured AComA aneurysms with unilateral infra-optic course of the A1-ACA. In both the cases, the preoperative catheter angiography revealed low bifurcation with a horizontal course of internal carotid artery. In our first case, the finding was rather unexpected; however, in our second case, we could anticipate an infra-optic course of A1-ACA. Preoperative recognition of this anomaly helps in achieving proximal vascular control with ease and confidence. It also enhances surgical safety of aneurysm clipping, by avoiding unnecessary dissection elsewhere. This emphasizes the importance of careful preoperative angiographic evaluation. In the presence of this anomaly, one should always search for other associated vascular anomalies.

Fetal-type posterior cerebral artery (FTP) is a common anatomic variation that is closely associated with intracranial aneurysm. In the present study, multislice computed tomography angiography (CTA) was performed to assess whether FTP is a risk factor for intracranial aneurysm. CTA data of 364 consecutive cases of patients who were suspected with cerebrovascular disease or intracranial aneurysm of intracranial artery from 2013 to 2016 were reviewed and the incidence rates of FTP, other variations of the circle of Willis, intracranial aneurysm and FTP with intracranial aneurysm were evaluated. The χ2 test was used to assess the influence of FTP and gender on the incidence rates of other variations of the circle of Willis, intracranial aneurysm and internal carotid artery-posterior communicating artery (ICA-PComA) aneurysm. Binary logistic regression analysis was performed to assess the associations of FTP and gender with intracranial aneurysm and ICA-PComA aneurysm. Compared with non-FTP patients, FTP cases exhibited significantly higher rates of other variations of the circle of Willis (χ2=80.173, P

Background: Digital subtraction angiography (DSA) is an important diagnostic tool for aneurysmal subarachnoid haemorrahage (SAH). Objectives: The purpose of the present study was to observe the findings of DSA in patients with SAH. Methodology: This cross-sectional study was performed in the Department of Neurology at Dhaka Medical College Hospital, Dhaka from December 2009 to November 2010 for a period of one (1) year. Patients at any age in both sexes who were admitted with SAH were included by purposive sampling technique. Demographic and clinical data were recorded in a semi-structured questionnaire. Angiography was performed after 4 weeks by DSA technique among all patients. Results: The mean age of the participants was 44.9±9.7 years (mean±SD). Male female ratio was 3:2. Hypertension, smoking, diabetes mellitus and family history of SAH were found in 14(46.6%) cases, 13(43.3%) cases, 3(10.0%) cases and 2(6.7%) cases patients respectively. All the study patients (100%) had headache and vomiting while 19(63.3%) cases had history of unconsciousness. Signs of meningeal irritation were present in 23(76.7%) patients. Anterior communicating artery was the most common site of aneurysm (36.7%) followed by middle cerebral (26.7%) and posterior communicating artery (23.3%). Majority of aneurysms were medium sized (46.7%), while 33.3% were small and 20.0% were large. Saccular aneurysm was found in 93.3% and aneurysms of narrow neck size in 86.7%. Conclusions: DSA has demonstrated that anterior communicating artery is the most common site of aneurysms in patients with SAH and is most often saccular with a narrow neck. Journal of National Institute of Neurosciences Bangladesh, 2016;2(2): 51-54

We reviewed basic considerations in fluid dynamics of cerebral aneurysms and applied these in surgery on the three most common types: internal carotid-posterior communicating artery, middle cerebral artery, and anterior communicating artery. It was found that aneurysmal initiation and growth do not occur at symmetric bifurcations. As blood flow always obeys the law of inertia, jet flow into the aneurysm will disperse along the wall; assuming the aneurysmal wall strength is even, the shape of the aneurysm becomes round or oval. When neurosurgeons encounter an aneurysm that is not round or oval, the wall may be fragile and requires great care during surgical manipulation.

Anterior communicating artery (ACoA) aneurysms are a frequently encountered cerebrovascular entity that is associated with a high rupture rate at a smaller size and debilitating morbidity and mortality following rupture. The surgical management of ACoA aneurysms is highly dependent on the spatial orientation of the saccular projection, which is categorized as inferior, superior, anterior, or posterior. The inferiorly projecting aneurysms constitute a minority of all aneurysms involving the ACoA. The adherence of the aneurysm dome near the chiasm predisposes these patients to dome avulsion during frontal lobe retraction. This patient presented with a 1-mo history of progressive vision loss and was found to have a large inferiorly projecting ACoA saccular aneurysm measuring 2.04 cm × 1.54 cm with resultant chiasmopathy. The lesion was approached via a right modified orbitozygomatic craniotomy, which can provide a more favorable maximal angle of approach to the ACoA complex to avoid brain retraction. Intraoperative adenosine was administered to provide relaxation of the aneurysm dome to augment clip placement. Postoperatively, the patient's chiasmopathy demonstrated near-complete resolution. The patient gave informed consent for surgery and video recording. Institutional review board approval was deemed unnecessary. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

Objective: Patients sustaining aneurysmal subarachnoid hemorrhage (aSAH) can be further complicated by neurogenic pulmonary edema (NPE) and Takotsubo-like cardiomyopathy (TCM) with dismal outcomes. The present study aimed to validate the efficacy of endovascular therapy for patients with aSAH complicated by NPE and TCM. Materials and Methods: Patients who were diagnosed with aSAH complicated by NPE and TCM and treated by endovascular therapy were retrospectively evaluated. Results: In the past 5 years, a total of ten female patients with aSAH were also diagnosed with NPE and TCM. Six of the ten were cases with high-grade aSAH (Hunt and Hess Grades IV and V), whereas four were low-grade aSAH (Grades II and III). The locations of ruptured aneurysms were the internal carotid-posterior communicating artery junctional site in five patients, the anterior communicating artery in two, the vertebral artery in two, and the middle cerebral artery in one. These aneurysms were successfully embolized by endovascular therapy without any procedure-associated complications. The clinical outcome measure at 6 months after discharge on the Modified Rankin Scale was found to be 0 in four patients, 1 in two, 3 in one, and 5 in three. Conclusions: Endovascular therapy can be a feasible, alternative measure for the treatment of patients with high-grade aSAH who also have NPE and TCM.

OBJECTIVEDuring surgical clipping of internal carotid artery (ICA)–posterior communicating artery (PCoA) aneurysms, proximal vascular control (PVC) is difficult to achieve in some cases because of variations in the anatomy of this type of aneurysm and its parent arteries. The authors investigated morphometric features that may be predictive for the necessity of anterior clinoidectomy (ACL) or cervical ICA exposure for PVC.METHODSThe authors retrospectively reviewed 65 patients with an ICA-PCoA aneurysm treated with clipping during the previous 3 years. The factors considered for assessing the difficulty of attaining PVC included the following: the maximum diameter of the aneurysm; the distance between the tip of the anterior clinoid process (ACP) and the proximal aneurysmal neck; the presence of calcification at the ophthalmic segment of the ICA; and the angles between the communicating segment of the ICA and the ophthalmic segment of the ICA and a line perpendicular to the cranial base, which reflect the tortuosity of the ICA. These parameters were measured based on preoperative CTA results.RESULTSIn a total of 21 patients (32.3%), PVC was difficult to perform with the usual pterional approach. In 6 patients, temporary artery occlusions (TAOs) were difficult to achieve because of severe atherosclerotic wall changes in the ophthalmic segment of the ICA. For 15 patients, the ACPs overhanging the ophthalmic segment of the ICA obstructed the ability to secure a space for TAO. In the 21 patients with PVC difficulty, ACL alone, cervical ICA exposure alone, and both ACL and cervical ICA exposure were conducted in 6, 8, and 7 patients, respectively. Multivariate analysis with binary logistic regression revealed that the maximum diameter of the aneurysm (p = 0.041), the distance between the proximal neck of the aneurysm and the ACP tip (p = 0.002), and calcification of the ICA ophthalmic segment (p = 0.001) were significant predictive factors for difficulties with PVC. A receiver operating characteristic curve analysis revealed that a distance between the proximal aneurysmal neck and the ACP tip of ≤ 5.4 mm was the best cutoff value for predicting the difficulty of attaining PVC (area under the curve 0.800, sensitivity 80.0%, specificity 80.0%).CONCLUSIONSA short distance between the proximal aneurysmal neck and the ACP tip and the presence of calcification at the ophthalmic segment of the ICA on preoperative CTA are helpful for predicting the difficulty of achieving PVC.

Precautious balloon test occlusion (BTO) is sometimes performed in cases of high-risk intraoperative internal carotid artery injury. We investigated whether magnetic resonance angiography (MRA) findings could predict BTO results to thus avoid the use of precautious BTO. This retrospective study, included 96 patients who underwent BTO, eight of whom underwent bilateral BTO. The relationship between the BTO results for 104 internal carotid arteries and the MRA findings obtained in 96 patients were retrospectively evaluated. On MRA, anterior cerebral artery (A1)–anterior communicating artery–A1 was defined as anterior collateral circulation (ACC), and posterior cerebral artery–posterior communicating artery was defined as posterior collateral circulation (PCC). BTO was tolerated in all 27 sides with thick ACC regardless of PCC thickness. In 31 of 44 cases with a thin ACC, the tested sides were BTO-tolerant (70.5%). Of these 44 tested sides, all five with a thick PCC were BTO-tolerant, but eight with a thin PCC and 31 with an invisible PCC showed results other than tolerance. Among cases with an invisible ACC, 10 of 33 tested sides were BTO-tolerant (30.3%). Among these 33 tested sides, outcomes other than tolerance were observed regardless of PCC thickness. Thick, thin, and invisible ACCs were assigned 3, 1, and 0 points, respectively; and thick, thin, and invisible PCCs were assigned 2, 1, and 0 points, respectively. A sum of 3 points in the ACC and PCC indicated that all sides were BTO-tolerant. In conclusion, a thick ACC or a thin ACC with a thick PCC indicates BTO-tolerance. The BTO prediction score is useful for predicting results of BTO.