Complex Cerebral Aneurysms Research Articles

Bayesian reconstruction of 3D particle positions in high-seeding density flows

Abstract Measuring particles' three-dimensional (3D) positions using multi-camera images in fluid dynamics is critical for resolving spatiotemporally complex flows like turbulence and mixing. However, current methods are prone to errors due to camera noise, optical configuration and experimental setup limitations, and high seeding density, which compound to create fake measurements (ghost particles) and add noise and error to velocity estimations. We introduce a Bayesian Volumetric Reconstruction (BVR) method, addressing these challenges by using probability theory to estimate uncertainties in particle position predictions. Our method assumes a uniform distribution of particles within the reconstruction volume and employs a model mapping particle positions to observed camera images. We utilize variational inference with a modified loss function to determine the posterior distribution over particle positions. Key features include a penalty term to reduce ghost particles, provision of uncertainty bounds, and scalability through subsampling. In tests with synthetic data and four cameras, BVR achieved 95% accuracy with less than 3% ghost particles and an RMS error under 0.3 pixels at a density of 0.1 particles per pixel (ppp). This shows 57% to 97% less ghost particles and 1.3 to 2 times lower RMS error than standard MART and IPR reconstructions. In an experimental Poiseuille flow measurement, our method closely matched the theoretical solution. Additionally, in a complex cerebral aneurysm basilar tip geometry flow experiment, our reconstructions were dense and consistent with observed flow patterns. Our BVR method effectively reconstructs particle positions in complex 3D flows, particularly in situations with high particle image densities and camera distortions. It distinguishes itself by providing quantifiable uncertainty estimates and scaling efficiently for larger image dimensions, making it applicable across a range of fluid flow scenarios.

Flow Diverter

The flow diverter is a relatively new but revolutionary technology in the realm of Endo vascular management of complex cerebral aneurysms. The traditional approach in the past has been stent deployment assisted coil embolisation. However, this maybe associated with partial occlusion or late recanalisation of the aneurysm. While planning the procedure for any cerebral aneurysm, the neurosurgeon needs to consider the morphology of the intracranial aneurysm as well as its proximity to the vascular branches and perforators. Giant (>25mm diameter), large (>10mm diameter), wide necked and fusiform aneurysms are the most challenging ones to treat.(1) The flow diverter works on the following principles (a)the stent deployed disrupts the blood flow from the parent vessel into the aneurysm (b) the stent works like a scaffolding for the growth of endothelial cells and separates the aneurysm from the parent vessel and gradually blocks it.(2) It is inducing endoluminal reconstruction in contrast to endosaccular filling in the older procedures. Moreover, it spares the origin of perforators from getting occluded. The sac gradually shrinks and finally collapses. This has excellent outcomes in comparison to conventional procedures for large or wide-necked aneurysms. This fascinating, innovative technology is associated with lesser complications and higher success rates. It is backed by landmark trials including the ‘Pipeline Embolisation Device for the Intracranial treatment of Aneurysms (PITA)’ trial and the ‘Pipeline for Uncoilable or Failed Aneurysms (PUFs) trial.(1) The device has thrombogenic potential and the patient needs to be on anti platelet therapy to prevent thromboembolism and late in-stent stenosis. A diversified complex case of multiple giant internal carotid artery aneurysms managed by latest phenomenal advanced technique of flow diversion in Neurointervention spectrum, that is, FLOW DIVERTER (FD). This young lady presented with sudden onset right sided complete opthalmoplegia and headache. Her investigations revealed bilateral ICA large to giant aneurysms. Considering all aspects of her case, she was counselled and planned for FD placement with some coils.

The application of high-resolution vessel wall imaging in the in situ bypass surgeries for complex anterior cerebral artery aneurysms

ObjectiveComplex anterior cerebral artery (ACA) aneurysms are still technically challenging to treat. Bypass surgery is needed to achieve aneurysm obliteration and ACA territory revascularization. Severe atherosclerosis of aneurysm walls can cause clip slippage, intraoperative rupture, postoperative ischemic events. How to assess the atherosclerotic changes in vascular walls by high-resolution vessel wall magnitude resonance imaging (VWI) is the key question in complex ACA aneurysm surgical management. MethodsThis retrospective single-center study included eight patients diagnosed with complex anterior cerebral arteries admitted to our hospital for bypass surgery from January 2019 to April 2022. We discussed the application of VWI in aneurysms treated with in situ bypass and reviewed previous experience of revascularization strategies for complex ACA aneurysms. ResultsIn this study, we treated 8 cases of complex ACA aneurysms (3 communicating aneurysms/5 postcommunicating aneurysms) over the prior one year. In situ side-to-side anastomosis (1 A2-to-A2/6 A3-to-A3) was performed in seven cases, and trapping combined with excision was performed in another case. Following bypass, complete trapping was performed in 4 cases, and proximal clipping was performed in 3 cases. No surgery-related neurological dysfunctions were observed. The final modified Rankin scale was 0 in seven of the eight cases and 2 in one case. ConclusionHigh-resolution VWI, as a favorable preoperative assessment tool, provides insight into patient-specific anatomy and microsurgical options before operations, which can help neurosurgeons develop individualized and valuable surgical plans.

OUTCOME EVALUATION OF FLOW DIVERTER STENT PLACEMENT IN TREATMENT OF RUPTURED AND UNRUPTURED CEREBRAL ANEURYSMS

Background: Cerebral aneurysms affect about 5% of the population and are associated with high mortality rates and severe complications for families and society. Complex aneurysm types include giant aneurysms, wide - necked aneurysms, blister - like aneurysms, recurrent aneurysms, fusiform aneurysms, and multiple aneurysms, which are difficult to manage with conventional endovascular or surgical methods due to complications such as coil migration and high rates of re - rupture. The development of flow diverter stents has been a breakthrough in recent decades and has been demonstrated to be safe and effective in treating aneurysms. The aim of this study was to evaluate the outcomes of flow diverter stent placement in the treatment of ruptured and unruptured cerebral aneurysms. Methods: This was a descriptive prospective study that followed up on 23 patients diagnosed and treated for cerebral aneurysms with flow - diverter stent intervention at the Stroke Department of Hue Central Hospital from 6/2020 to 6/2022. The follow - up data after 6 months and 12 months were recorded. Results: There were 23 patients (9 males, 14 females) with 28 cerebral aneurysms, with a mean age of 51.7 ± 9.9 years. Aneurysms were predominantly located in the anterior circulation (85.7%) and 14.3% in the posterior circulation. The most common aneurysm type was fusiform (75%), followed by dissecting (17.9%) and blister - like (7.1%). Most aneurysms had wide necks, with a neck - to - dome ratio < 1.5, accounting for 82.1%. Flow diverter stent placement was successfully performed in 91.3% of patients, with 27 stents used. Stents were properly positioned, well - expanded in 88.9%. The complication rate after intervention was 4.3%. Complete aneurysm occlusion rates at 6 to 12 months were 92.9% and 96.4%, respectively. The rate of mild in - stent stenosis without clinical symptoms was 4.3%. The good outcome rate (mRS 0 - 2) was 91.3%. Conclusion: Flow diverter stent is effective and safe with high rate of successful and low procedural complications in the treatment of complex cerebral aneurysms.

The off-label uses of pipeline embolization device for complex cerebral aneurysms: Mid-term follow-up in a single center.

To describe the off-label uses of pipeline embolization device for a variety of types of aneurysms including ruptured aneurysms, posterior circulation aneurysms, small aneurysms, distal aneurysms, and recurrent aneurysms. Clinical and angiographic data of patients who underwent pipeline embolization device treatment on off-label use at our center were retrospectively reviewed. For categorical variables, Fisher's exact test was used, and a two-sample Wilcoxon rank-sum test was used for patients' age to analyze the correlation with outcomes. In this study, 121 aneurysms in 107 patients received off-label pipeline embolization device treatments. The overall rate of complete aneurysm occlusion was 77.8% (28/36 in 35 patients) for posterior circulation aneurysms and 95.3% (81/85 in 72 patients) for anterior circulation aneurysms. The posterior circulation aneurysms have a lower rate of aneurysm occlusion (p = 0.0372). The small aneurysms have a higher rate of aneurysm occlusion (p = 0.0104). The patient's sex, age, and aneurismal size were associated with ischemic stroke complications (p = 0.0397, 0.0166, and 0.0178). In posterior circulation aneurysm patients, only two basilar apex aneurysms underwent pipeline embolization device treatment, both of whom died of thrombotic complications. There was no difference in mortality between posterior circulation aneurysm patients (8.6%, 3/35) and anterior circulation aneurysm patients (1.4%, 1/72) (p = 0.1015). Patients of older age have a higher risk of death rate (p = 0.0053). The off-label use of pipeline embolization device is often performed in clinical practice and can achieve efficacy in complex aneurysms. The off-label use of pipeline embolization device was found to carry an increased rate of mortality in older patients. Excluding basilar apex aneurysms, the pipeline embolization device is as safe as anterior circulation aneurysms in the treatment of posterior circulation aneurysms elsewhere.

Surgical revascularization (bypass surgery) in the treatment of complicated cerebral aneurysms

The aim of surgical treatment of any cerebral aneurysm is to achieve its total exclusion from the bloodstream. Although the progress in the development and implementation of microsurgical and the latest endovascular technologies, in many cases, the treatment of complex cerebral aneurysms is not an easy task. Unsatisfactory results of the exclusion of complicated cerebral aneurysms are due to many factors, for instance: gigantic size, fusiform or dolichoectatic configuration of the cerebral aneurysm, the presence of atherosclerotic changes, anatomical features of the departure of functionally important arteries directly from the cerebral aneurysm. Such cerebral aneurysms are quite problematic both for microsurgical remodeling clipping and for endovascular exclusion. At the current stage, the introduction and use of the microanastomosis technique provides additional options and expands the possibilities of surgical treatment of complex cerebral aneurysms.Objective ‒ to analyze the possibilities and results of surgical treatment of complicated cerebral aneurysms using the technique of surgical revascularization (bypass surgery).Materials and methods. An analysis of the results of the examination and surgical treatment of 16 patients with complicated cerebral aneurysms for the period from 2016 to 2020, who were treated and operated on in the emergency vascular neurosurgery department with the X-ray operating department Romodanov Institute of Neurosurgery of NAMS of Ukraine. All patients diagnosed with complicated cerebral aneurysms had gigantic sizes. All cases of surgical intervention included placement of extra-intracranial microanastomosis or intra-intracranial anastomosis, sometimes a combination of it, to ensure normal blood supply to the vessel of complicated cerebral aneurysm that were planned to be devascularized. In 14 observations, one-time anastomosis and exclusion of complicated cerebral aneurysms were performed. In 2 observations, the first stage was an anastomosis without exclusion of the complicated cerebral aneurysms due to insufficient vascularization of the distal arterial branch for deconstructive exclusion of aneurysm.Results. Satisfactory results of surgical treatment (grade 1 and 2 of Modified Rankin Scale (MRS)) in the general group of patients were observed in 13 (81 %) patients with complicated cerebral aneurysms. Unsatisfactory results of surgical treatment occurred in 3 (19 %) observations. Profound disability (MRS grade 5) as a result of surgical treatment was recorded in 1 (6 %) patient. Cases that ended fatally occurred in 2 (13 %) observations of the total group of patients. In the group of patients with surgical revascularization and excluded complicated cerebral aneurysms, satisfactory results were observed in 13 (92.9 %) patients. Fatal results of surgical treatment were recorded in 2 patients with a hemorrhagic course of complicated cerebral aneurysms, in which surgical revascularization was performed as first stage and scheduled removal of complicated cerebral aneurysms was planned.Conclusions. The introduction and use of the microanastomosis technique expands the possibilities of surgical treatment of complicated cerebral aneurysms. Revascularization surgical interventions are highly effective in the prevention of ischemic complications when complicated cerebral aneurysms are excluded. Recommendations (indications) for revascularization should be considered in impossibility and high risks of ischemic complications during remodeling clipping or endovascular exclusion of complicated cerebral aneurysms.

Intrasaccular neck-bridging: A technical note on Nautilus-assisted coiling of wide-necked cerebral aneurysms. Feasibility study, immediate and early angiographic results.

Various adjunctive devices have been reported to be helpful during the endovascular coiling of complex, wide-necked cerebral aneurysms. This study aimed to describe the utilization of a recently introduced intrasaccular neck-bridging implant specifically designed to facilitate coil embolization. We retrospectively reviewed eight consecutive patients who underwent treatment for intracranial aneurysms with the Nautilus intrasaccular bridging system between February 2022 to May 2022. We evaluated the angiographic appearances of treated aneurysms at the end of the procedure and early follow-up, the clinical status and complications. Eight patients with eight cerebral aneurysms (3 men and 5 women, mean age 52.8 years (range 39-66) were analyzed. Five of the treated aneurysms were managed in an acute case scenario. There were no technical difficulties while executing the technique. No other procedural adverse events were documented. Immediate complete occlusion of the aneurysm was seen in 6 patients, neck remnant in 1 and stable aneurysm reperfusion in one case. Early radiological follow-up was available in five patients, and the observed occlusion rates were - RR class I in all radiologically screened aneurysms. Nautilus-assisted coil embolization represents a rapid and safe solution for complex cerebral aneurysms. In our opinion this device symbolizes a significant step forward in treating intracranial aneurysms. We believe that the technique's actual value consists of the fact that the device is fully compatible with the modern low-profile microcatheter technology and does not involve the need for antiplatelet medications.

Mathematical modeling of high-flow extra-intracranial bypass in the treatment of a complex cerebral aneurysm

Intracranial aneurysms (IAs) pose a high risk of spontaneous subarachnoid hemorrhage. In the most complex cases, the only way to exclude the aneurysm from the circulation is to perform a high-flow extracranial-to-intracranial bypass, thus creating a new bloodstream. This avoids severe ischemic complications; however, it requires careful consideration of individual anatomy and hemodynamic parameters. Computational fluid dynamics (CFD) can be of great help in planning such a surgery by creating 3D patient-specific models of cerebral circulation. Assessment of the perspectivity of high-flow extracranial-to-intracranial bypass planning using computational modeling. In this research work, we have applied the CFD methods to a patient with a giant thrombosed IA of the internal carotid artery (ICA). Preoperative CTA images and Gamma Multivox workstation were used to create a 3D model with current geometry and three additional models: Normal anatomy (no IA), Occlusion (with ligated ICA), Virtual bypass (with bypass and ligated ICA). The postoperative data were also available. Boundary conditions were based on PC-MRI measurements. Calculation of hemodynamics was conducted with a finite element package ANSYS Workbench 19. The results demonstrated an increase in the blood flow on the affected side by more than 70% after the virtual surgery and uniformity of flow distribution between the affected and contralateral sides, indicating that the treatment is likely to be efficient. Later, postoperative data confirmed that. The study showed that virtual preoperative CFD modeling could significantly simplify and improve surgical planning.

The complementary multimodal treatment of recalcitrant cerebral aneurysms

Background: The main treatment of cerebral aneurysms is direct surgical clipping or endovascular coil embolization. However, some cerebral aneurysms that we reviewed in the literature are still not susceptible to a single treatment approach. These aneurysms can be referred to as complex aneurysms.
 Objective: We aim to report these aneurysms and share our clinical experience with their treatment and diagnosis.
 Methods: All cases of cerebral aneurysms treated in New York University and in Mansoura University from 2010-2021 were retrospectively reviewed.
 Results: 18 patients with 21 cerebral aneurysms were treated by combined surgical and endovascular modalities. Aneurysms associated with arteriovenous malformations (AVMs) in 3 patients, associated with vasospasm in 7 patients, and 3 patients had double aneurysms. A total of 18 patients with aneurysms were treated with combined endovascular and microsurgical therapy. Early angiogram (< 1 week) revealed; complete obliteration of 19 aneurysms (90%) out of a total of 21 aneurysms, residual filling was observed in 2 aneurysms (10%). Late radiological follow up (> 3 months- 2 years) revealed; a stable residual filling in one and the other case underwent retreatment.
 Conclusions: The recalcitrant or complex cerebral aneurysms can be better referred to as diseases rather than lesions as many clinical and anatomical factors make their treatment difficult. Endovascular and microsurgery could be complementary to each other and create a multimodal approach for treating them.

Double-barrel STA-MCA bypass for cerebral revascularization: lessons learned from a 10-year experience.

In select patients, extracranial-intracranial (EC-IC) bypass remains an important tool for cerebral revascularization. Traditionally, superficial temporal artery-middle cerebral artery (STA-MCA) bypass was performed using one limb of the STA only. In an attempt to augment flow and to direct flow to different ischemic areas of the brain, the authors adopted a "double-barrel" technique in which both branches of the STA are used to revascularize distinct MCA territories. A series of consecutive double-barrel STA-MCA bypasses performed between 2010 and 2020 were reviewed. Each anastomosis was directed to augment flow to a territory most at risk based on preoperative perfusion studies, cerebral angiography, and intraoperative indocyanine green data. CT perfusion and CTA were routinely used to evaluate postoperative augmentation and graft patency. Patient perioperative outcomes, surgical complications, and modified Rankin Scale (mRS) scores at the last follow-up were reported. Forty-four patients (16 males, 28 females) successfully underwent double-barrel STA-MCA bypass on 54 cerebral hemispheres: 28 operations were for moyamoya disease, 23 for atherosclerotic disease refractory to medical therapy, 2 for complex cerebral aneurysms, and 1 for carotid occlusion as a sequela of cavernous meningioma growth. Ten patients underwent multiple operations, 9 of whom had moyamoya disease/syndrome, with the subsequent operation on the contralateral hemisphere. The average patient age at surgery was 45.1 years (range 14-73 years), with a mean follow-up time of 22.1 months. Intraoperative graft patency was confirmed in 100% of cases, and 101 (98.1%) of the 103 anastomoses with imaging follow-up were patent. Perfusion to the revascularized hemisphere was improved in 88.2% of cases. Perioperative ischemic and hemorrhagic complications occurred in 8 procedures (2 were asymptomatic), whereas remote ischemic and hemorrhagic events occurred in 7 cases. There was no mortality in the series, and the mean patient mRS scores were 1.72 at presentation and 1.15 at the last follow-up. The high rates of intraoperative and postoperative patency support the feasibility of dual-anastomosis STA-MCA bypass for revascularization. The perioperative complication rate is not significantly different from that of single-anastomosis bypass. The functional outcomes at follow-up and perfusion improvement postoperatively support the efficacy and safety of this method as a treatment strategy.

Single-Institute Experience of Bypass Surgery for Complex Anterior Cerebral Artery Aneurysms: Paying Special Attention to the Spatial and Diameter Relationship Between the Efferent Arteries

To present a retrospective review of a single-institute experience with bypass surgery of complex anterior cerebral artery aneurysm. Eight patients (5 females and 3 males; mean age, 34.2 years) with complex anterior cerebral artery aneurysms were treated with bypass. There were 3 precommunicating aneurysms, 1 communicating artery aneurysm, and 4 postcommunicating aneurysms (2 in A2 and 2 in A3). A3-A3 side-to-side in situ bypass was performed in 6 cases. A3-radial artery-A3 interpositional bypass was performed in 1 case with A3 segments located far apart, and A3-A3 transplantation was performed in 1 case with nonparallel aligned A3 segments. Of the 8 aneurysms, 3 were secured with proximal clipping, 1 was secured with distal clipping, 1 was secured with direct clipping, 1 was secured with isolation, and 2 were secured with embolization. Aneurysm obliteration was achieved in all cases. Only 1 in situ bypass from a smaller donor artery to a larger recipient artery failed with minor postoperative infarction. Intraoperative bleeding from the site of anastomosis occurred in 1 case during embolization. All patients had complete recovery with normal neurological function during follow-up at outpatient clinics. We established a simplified surgical algorithm for complex anterior cerebral artery aneurysms based on the geometrical and spatial relationship between efferent arteries. The reasons for bypass failure and hemorrhagic complication were also discussed.

M2 plane rotation technique for approaching M2 perpendicularly to obliterate aneurysms with interlocking clipping: Technical case report

IntroductionThe interlocking tandem clipping technique allows a surgeon to effectively obliterate the morphologically complex middle cerebral artery aneurysm. However, applying clips perpendicular to the M2 plane is sometimes challenging, even after meticulous arterial dissection and wide dissection of the Sylvian fissure. We present herein a surgical case of a middle cerebral artery aneurysm, and demonstrate a feasible method by which to rotate the M2 plane and apply the clip perpendicular to the M2 plane. Case illustrationA 44-year-old woman presenting with severe headache was admitted to our hospital. Cerebral digital subtraction angiography showed a small saccular aneurysm arising from the left M2 bifurcation. Due to aneurysm neck overhang of the posterior aspect of the bifurcation, the base of the aneurysm was likely to remain following simple parallel clipping of the efferent artery. Therefore, an interlocking tandem clipping technique was considered. Clip application was needed perpendicular to the M2 plane, but the M2 plane was not perpendicular in the line of sight, even after meticulous arterial dissection. We pushed the superior division of the middle cerebral artery inferiorly and pulled the artery medially using an aspiration tube, which allowed the M2 plane to be rotated medially. This allowed application of both a straight mini-clip and an angled fenestrated mini-clip perpendicular to the M2 plane, resulting in successful aneurysm obliteration without a remnant. ConclusionThe presented feasible method allows easy rotation of the M2 plane and application of the clip perpendicular to the M2 plane.

The neurointerventional paradox: ensuring patient safety without restricting technological innovation

As a result of the collaboration between scientists, physicians, the pharmaceutical and medical device industry, and overseeing regulatory bodies such as the Food and Drug Administration (FDA), the diagnosis and...

A Hybrid Strategy for Patients With Complex Cerebral Aneurysm: STA-MCA Bypass in Combination With Endovascular Embolization.

Objective: This work aims to present our experience of patients with complex cerebral aneurysm treated with a hybrid approach: superficial temporal artery–middle cerebral artery (STA–MCA) bypass in combination with endovascular exclusion of the aneurysm.Method: Patients with aneurysms deemed unclippable and uncoilable were included. All patients were treated with a hybrid approach. After STA–MCA bypass, the parent artery was temporarily occluded. If the intraoperative motor evoked potential (MEP) and somatosensory evoked potential (SEP) waveforms remain normal and last for 30 min, the aneurysm and te parent artery will be embolized permanently with detachable balloons or coils.Results: A total of 20 patients with 22 aneurysms were included in this study. There were 13 women and 7 men, with an average age of 42.5 years. Intraoperative angiography showed the good patency of all the STA grafts, and neither SEP nor MEP abnormalities were detected. After the parent artery and the aneurysm were occluded, the intraoperative angiography showed an immediately successful exclusion of the aneurysm in 20 aneurysms and immediate contrast stasis in two. All patients recovered uneventfully without ischemic or hemorrhagic complication. Angiography at 6-month follow-up showed the total obliteration in 20 aneurysms. Two aneurysms showed residuals and were recoiled. All STA grafts showed a good patency, and the mean graft flow was 124.2 ml/min.Conclusion: STA–MCA bypass in combination with endovascular exclusion is an appropriate option for patients with complex cerebral aneurysms that are not amenable to direct surgical clipping or endovascular embolization.

脳動脈瘤に対するHybrid Neurosurgery ～より安全な手術への取り組みとして～

脳動脈瘤に対するHybrid Neurosurgery ～より安全な手術への取り組みとして～

Acutely ruptured basilar artery bifurcation aneurysm, treated with simultaneous Cascade and Comaneci temporary-assisted coiling

Temporary stent-assisted coiling is an eligible approach for the treatment of acutely ruptured complex cerebral aneurysms. Improved material properties and industrial advances in braiding technology have led to the introduction...

Natural Y-shaped radial artery graft bypass for a complex middle cerebral artery aneurysm: A case report

Giant thrombosed middle cerebral artery (MCA) aneurysms are difficult to treat and sometimes require complex revascularization using allografts. We describe a technical method using revascularization with a natural Y-shaped graft that provides a normal variation for a complex MCA aneurysm. A 65-year-old man with a giant thrombosed MCA aneurysm presented with right hemiparesis and aphasia. The patient had a history of clipping surgery for the ipsilateral side of the MCA aneurysm 25 years before, and a de novo aneurysm developed over the previous 18 years. For the giant thrombosed aneurysm, trapping and revascularization were performed. A natural radial artery Y-graft was used as the graft and anastomosed to both M2 trunks. The symptoms improved after surgery, and the patient was discharged 3 weeks later. This is the first report of a double-barrel bypass using a natural Y-graft. This method attained a normal variation, and the flow of the Y-graft was physiological. For the radical cure of giant thrombosed MCA aneurysms, multiple revascularizations might be required. With this natural Y-graft, complex transpositions could be avoided.

A Case Report of an AppSurgeOn-Assisted Complex Cerebral Aneurysm Surgery: A New Frontier for Education and Operative Planning

With the increased interactivity and sophistication of apps, more specialty-specific apps are continuously invented with intentions to simulate the operative technique in a step-by-step approach. AppSurgeOn Neurosimulator, Vol. I is the first 3D neurosurgical simulator for use on smartphones and tablets. A 59-year male presented to the emergency department of another hospital with the sudden disturbed level of consciousness. Radiology showed a complex anterior communicating artery aneurysm that requires surgical clipping. The surgery was conducted fluently, then the patient improved gradually and discharged fully conscious with no neurological deficit. Our initial experience with this app shows that it is a helpful tool for not only the neurosurgeon but the entire team and the patient’s family. The single platform is diverse and has numerous applications, including simulation, planning and education. It provides the surgeon with a degree of surgical rehearsal in preparation for a case, which in turn offers increased operative speed and precision. Such preoperative familiarity promotes mastery of the whole procedure, from patient positioning to dissection. AppSurgeOn facilitates the explanation of the procedure to the patients and their family through the use of its intuitive 3D model and visually approachable spatial representation. The AppSurgeOn – Neurostimulator Vol. I mobile app represents a realistic adjunct for complex neurosurgical procedures and can have an immense impact on the delivery of care and the potentials for patient satisfaction

Platelet Function Testing with a VerifyNow-Directed Personalized Antiplatelet Strategy and Associated Rates of Thromboembolic Complications After Pipeline Embolization for Complex Cerebral Aneurysms

VerifyNow-directed personalized antiplatelet therapy for aneurysm embolization with a Pipeline Embolization Device (PED) remains controversial. Evaluate thrombotic complications between patients who received VerifyNow-directed personalized antiplatelet therapy versus those who did not after PED flow diversion of complex cerebral aneurysms. This was a retrospective cohort of consecutive patients undergoing flow diversion with PED at the Medical University of South Carolina between January 2012 and May 2018. Patients who received VerifyNow-directed personalized antiplatelet therapy were compared with those who received antiplatelet therapy without platelet function testing. Patients with a P2Y12 reaction unit (PRU) ≥194 were deemed to be clopidogrel hyporesponsive. The primary outcome is the rate of thrombotic complications, and the secondary outcomes are the rate of hemorrhagic and thrombotic complications stratified by PRU and high-risk clinical and procedure-related candidate predictors. Thrombotic complications were not different between patients managed with (n= 159) versus without (n= 110) VerifyNow (6.9% vs. 7.3%; P= 0.911). Hemorrhagic complications were also no different (3.1% vs. 4.5%; P= 0.550). PRU stratification revealed no difference in thrombotic or hemorrhagic complications (P= 0.488 and P= 0.136, respectively). The only significant predictors for thrombotic complications were the presence of diabetes (OR 2.9; P= 0.034), obesity (OR 5.1; P ≤ 0.001), fusiform aneurysm (OR 3.3; P= 0.023), posterior circulation implantation (OR 3.4; P= 0.016), and >1 PED implanted (OR2.4; P= 0.046). The role of VerifyNow and personalized antiplatelet therapy in patients undergoing flow diversion with PED to treat complex aneurysms did not demonstrate a benefit in reducing thrombotic complications.

Internal Carotid Artery Test Balloon Occlusion Using Single Photon Emission Computed Tomography Scan in the Management of Complex Cerebral Aneurysms and Skull Base Tumors: A 20-Year Review

Test balloon occlusion (TBO) is important in the management of complex cerebrovascular and skull base lesions when permanent occlusion (PO) of a parent artery may be indicated. Several adjuncts may be used to increase the sensitivity of TBO to predict whether PO will be tolerated. This is an observational study to evaluate the utility of internal carotid artery (ICA) TBO using single photon emission computed tomography (SPECT) scan in the management of complex vascular pathology and skull base tumors. All TBO procedures performed over a 20-year period were analyzed. Clinical assessment and angiographic collateral flow were combined with semi-quantitative cerebral blood flow analysis using 99mTc hexamethylpropylene-amine oxime SPECT scan during ICA TBO. Evaluation of collateral circulation after TBO, and the complications of TBO and the safety of PO after successful TBO were evaluated. Eighty-three patients underwent TBO without complication. Of 45 patients with satisfactory TBO, 28 proceeded to PO. Three patients developed transient ischemic symptoms thought to be embolic in origin. Thirty-eight patients had unsatisfactory TBO, of whom 15 required PO accompanied by a bypass procedure. Forty patients in the series did not undergo permanent vessel occlusion. SPECT scan-enhanced TBO is an important component of the management of complex vascular pathology and skull base tumors, permitting safe PO of the parent vessel and definitive treatment of the main pathology.