Teleproctoring in therapeutic neurointervention: Experience from Iraq-Saudi Arabia collaboration.

Background: Proctoring in neuroendovascular surgery is one of the potential solutions for the shortage of personnel and experience, particularly in unstable and limited-resource areas such as Iraq. Methods: The study was conducted at the Baghdad Neurovascular Center (BNC), the first Hybrid neurovascular institution in Iraq, where sequential online zoom-based meetings between the BNC team and the expert from the Kingdom of Saudi Arabia were used for teleproctoring for neurointerventional procedures. Results: A total of 28 sessions were conducted, four sessions for each case. Seven cases with various intracranial vascular lesions were operated for neuroendovascular procedures from July/2021 to March/2022. The teleproctoring for each case included four sequential sessions: (1) preoperative planning, (2) device selection and preparation, (3) intraoperative live-stream proctoring, and (4) postoperative reflection and follow-up planning. The procedures include coiling for dural arteriovenous fistula; preoperative tumor embolization; preoperative, partial, and staged embolization for arteriovenous malformation; coiling for intracranial aneurysm; and attempted Giant aneurysm flow-diversion. Major complications were avoided through teleproctoring, and all patients had good outcomes. In addition, the teleproctoring provided an effective training experience to the local neuroendovascular team that is otherwise not feasible. Conclusion: Teleproctoring is an effective and feasible tool to improve patient outcomes and provide a training experience to the local neuroendovascular teams in resource-limited regions.

Difficult 6F Guiding Sheath Removal Using the Transradial Artery Approach: A Case Report.

Objective: Recently, the use of the radial artery approach for neuroendovascular treatment has become more frequent. The main advantage of this approach is that there is a low complication risk. However, in the aforementioned case, the 6F guiding sheath proved difficult to remove from the radial artery. Case Presentation: A 60-year-old female patient presented with an unruptured basilar tip aneurysm, which we treated with coil embolization under general anesthesia. We performed paracentesis on the right radial artery and inserted a 6F Axcelguide. The radial artery is bifurcated at the brachial region. We guided the Axcelguide to the right subclavian artery and filled the aneurysm with a coil. After embolization, we attempted to remove the Axcelguide. However, we encountered extreme resistance, and removal proved difficult. We injected verapamil, isosorbide nitrate, nitroglycerin, and papaverine hydrochloride intra-arterially and subcutaneously into the forearm and then performed a brachial plexus block. Unfortunately, the situation remained unchanged. We attempted to slowly remove the catheter with the vascular mass remaining adhered to it. We transected the radial artery in the middle. We could not achieve hemostasis through manual compression and thus injected n-butyl-2-cyanoacrylate intra-arterially. Postoperatively, the patient experienced mild subcutaneous hematoma and pain. Conclusion: We consider reporting this case valuable because no previous studies have described similar difficulties in removing a 6F guiding sheath from the radial artery.

Increased Multispectral CT Iodine Concentrations in Patients With Transient Neurological Deterioration Following Endovascular Neurointerventional Procedures: an Argument in Favor of the Elusive Contrast-Induced Encephalopathy?

BACKGROUND AND PURPOSE: So-called contrast-induced encephalopathy (CIE) is a rare but worrying condition occurring after cerebral angiography or neuroendovascular interventions using iodine contrast media. This study aimed to compare cerebral iodine concentrations in patients suspected of having CIE after endovascular procedures to those in matched controls. METHODS: This is a retrospective monocentric study of 25 suspected CIE patients in a tertiary care teaching hospital diagnosed from June 2017 to February 2024. Cerebral multispectral computed tomography (CT) iodine mean concentrations were measured and compared with 1:1 matched controls using the CT constructor's workstation in the whole brain and in specific regions of interest (ROIs) corresponding to a vascular territory downstream of the procedure. Concentration values were compared with paired samples t­test. RESULTS: During the study period, 1097 patients underwent aneurysm embolization and 137 arteriovenous malformation (AVM) embolization procedures. So-called CIE was suspected in 25 patients after aneurysm or AVM embolization (2%). Mean iodine concentrations in the procedure vascular territory ROIs were higher in suspected CIE cases (mean 543 ± 147 µg/cm3) compared to matched controls (mean 463 ± 141 µg/cm3; p = 0.01). Whole brain mean iodine concentrations were modestly higher in CIE patients compared to controls across all subgroups, without reaching statistical significance. CONCLUSIONS: CIE may be associated with modest increase in CT iodine concentration in the procedure vascular territory after neurointerventional procedures. The underlying pathophysiology of this condition remains uncertain and merits further investigation. KEY MESSAGES: Contrast-induced encephalopathy (CIE) is known as a rare neurologic condition following iodine contrast media use in neuroendovascular interventions, with unclear pathophysiology. WHAT THIS STUDY ADDS: This study provides evidence that suspected CIE is associated with higher cerebral iodine concentrations in affected vascular territories, a novel quantifiable change. Implications for research, practice, or policy: These findings suggest the potential for iodine concentration monitoring to refine CIE diagnosis and prevention strategies in clinical practice.

Transradial Angiography Skill Acquisition Using an Endovascular Simulation Program.

BACKGROUND: Given the benefits of neuroendovascular simulation to resident education, this study aimed to assess the efficacy of simulation-based training for neuroendovascular intervention with primary and secondary catheters using a transradial approach (TRA). METHODS: Five neurosurgical residents (PGY 1-3) from our institution enrolled in a standardized pilot training protocol. Trainees used the Mentice (Gothenburg, Vastra Gotaland, Sweden) Visit G5 simulator with a type II arch using a right TRA. RESULTS: All participants improved their total time to complete the task from the first trial to the last trial. Residents improved the overall time required to complete the task by 111.8 ± 57 seconds (52% improvement; P = 0.012). Participants reported improved knowledge of Simmons catheter formation from 1.6 ± 0.8 to 2.8 ± 1 (P = 0.035) and improved knowledge of transradial vessel selection technique from 1.6 ± 0.9 to 2.8 ± 1.1 (P = 0.035). All residents were able to illustrate a bovine arch and types 1-3 arches post-simulation. Residents rated the simulation usefulness as 4.6 ± 0.548 (scale 1 [not useful] to 5 [essential]) with 4 of the 5 residents (80%) identifying this exercise as essential. All residents rated the hands-on component of the training exercise as the most important. CONCLUSIONS: Residents demonstrated proficiency at Simmons catheter formation and vessel selection in a type II arch over a short time period (4 attempts and <1 hour total). Residents can use simulator-based training to increase their proficiency of vessel selection using a primary or secondary catheter for a TRA.

Rescue Stenting for Inadvertent Branch Vessel Occlusion Following Cerebral Aneurysm Embolization With the Woven EndoBridge Device.

Intrasaccular flow modification with devices like the Woven EndoBridge (WEB, MicroVention, Inc., Aliso Viejo, California, US) is an increasingly utilized endovascular treatment for bifurcation aneurysms. Among the potential complications of the procedure is branch vessel occlusion. There are no previous publications of rescue stenting for inadvertent branch vessel occlusion with the WEB device. We report two cases of rescue stenting following branch vessel occlusion after cerebral aneurysm embolization with the WEB device. In both cases, rescue stenting with a Neuroform Atlas stent Stryker, Fremont, CA, US) successfully revascularized the occluded vessel and led to good patient outcomes.

A Novel Training Method for Endovascular Clot Retrieval Using a Portable Vascular Model and Red Film.

Hands-on training is a crucial part of education in neuroendovascular treatment to ensure safe and rapid acquisition of techniques. However, there is a significant gap between training and actual clinical practice. This study will introduce innovations for more practical thrombus retrieval training that was developed in this process. A Smart Vascular Model 3 in 1 was used. A pink pseudothrombus was inserted into the M1 (horizontal segment of the middle cerebral artery) section of the model. Then, a "red underlay" purchased at a stationery store was placed to cover the proximal part of M1 and beyond so that the pseudothrombus was not visible. The thrombus was retrieved during training by looking for the location of the thrombus based on the behavior and resistance of the tip of the guidewire and deployment of the stent retriever. The participants were required to have detailed observation skills and precise manipulation skills using a red film to prevent the direct visualization of the pseudothrombus. The implementation of this innovation to the previous hands-on training made the training more practical and effective. If the exact thrombus location can be determined by the behavior of the wire tip, the device's capabilities can be maximized, and rapid retrieval can be expected. It could also reduce complications, as unnecessary peripheral guidance of the device could be avoided.

Neuroendovascular Rescue 2025: Trends in Stroke Endovascular Therapy.

Neuroendovascular rescue of patients with acute ischemic stroke caused by a large arterial occlusion has evolved throughout the first quarter of the present century, and continues to do so. Starting with the intra-arterial instillation of thrombolytic agents via microcatheters to dissolve occluding thromboembolic material, the current status is one that includes a variety of different techniques such as direct aspiration of thrombus, removal by stent retriever, adjuvant techniques such as balloon angioplasty, stenting, and tactical intra-arterial instillation of thrombolytic agents in smaller branches to treat no-reflow phenomenon. The results have been consistently shown to benefit these patients, irrespective of whether they had already received intravenous tissue-type plasminogen activator or not. Improved imaging methods of patient selection and tactically optimized periprocedural care measures complement this dimension of the practice of neurointervention.

Quantitative evaluation of the effects of flow diverter treatment on aneurysm hemodynamics using time-resolved rotational angiography.

BACKGROUND: There have been immense advancements in the hardware and software of digital subtraction angiography systems over the last several years. These advancements continue to make progress toward the goals of offering better visualization and reducing radiation exposure. A newer advancement in this arena is presenting three-dimension data over time resulting in four-dimensional-digital subtracted angiography visualization. We have evaluated these protocols related to the evaluation of the treatment of intracranial aneurysms with pipeline flow diversion. METHODS: Four-dimensional-digital subtracted angiography imaging was acquired on an Artis Q Biplane angiographic system (Siemens Healthcare AG, Forchheim, Germany). A six second four-dimensional-digital subtracted angiography protocol was performed pre and post flow diverter placement. Pre and post reconstructed images were sent through a dedicated prototype research workstation (Syngo X-Workplace; Siemens Healthineers AG) for further flow evaluation. RESULTS: The treatment of an aneurysm with flow diversion led to a filling delay of 0.278 ± 0.422 s inside the aneurysms, whereas distal to the aneurysms the filling of the vessel segment occurred earlier post procedural (negative filling delay of -0.15 ± 0.31 s. The flow ratio inside the aneurysm decreased to 63.6 ± 23% of its pre-treatment value and distal to the aneurysm the flow remained substantially the same (flow ratio: 95.6 ± 0.29%). Data showed a relative filling delay of the aneurysm normalized to the distal vessel of 0.43 ± 0.36 s. The relative flow ratio of the aneurysm in comparison to the distal parent vessel was 72.2 ± 31%. CONCLUSIONS: Analysis of a four-dimensional-digital subtracted angiography acquisition allows assessment of the effects of flow diversion treatment on aneurysm hemodynamic parameters and shows a significant decrease in flow inside the aneurysm compared to the parent vessel distal to the aneurysm.

Relationship between Shape Retention and X-ray Absorption Value of the Tip of Microcatheters in Neuroendovascular Treatment.

Objective We noticed that the X-ray absorption value of the tip of each microcatheter used for aneurysm treatment varied from product to product. We hypothesized that the differences were caused by variations in the metal's density braid, which could be related to the ability of the tip to retain its shape. Methods The X-ray absorption value of each microcatheter tip was measured. Next, heat forming was performed using a shaping mandrel at 6 mm and 90 degrees to determine whether there was a correlation between the X-ray absorption value and the forming angle. Next, the optimal mandrel angle for forming each microcatheter at 90 degrees was investigated. We also examined the shape retention after 20 times wire insertions into each microcatheter. Conclusion It was found that the higher the X-ray absorption value, the harder it was for the microcatheter to be formed. The mandrel angle required to form 90 degrees was determined by the X-ray absorption value. The higher the X-ray absorption value, the higher the shape retention of the tip shape. The heat formation and shape-retention conditions of the microcatheter tip were correlated with the X-ray absorption value of the metal braid. Even for unknown microcatheters, the optimum shaping conditions can be inferred from the X-ray absorption value.

Passive Approximator Vascular Closure Device Use in Patients with Shallow Femoral Artery Depth Increases Puncture-site Complications in Neuroendovascular Treatment.

OBJECTIVE: Puncture-site complications in interventional radiology sometimes cause severe conditions. Vascular closure devices play an important role in preventing puncture-site complications. Vascular closure devices are divided into 2 types, the directly suturing or clipping type (active approximators) and adherent sealant types (passive approximators). However, which types of vascular closure device are the safest and most effective for achieving hemostasis remains unclear. We analyzed the efficacy of each type of vascular closure device and risk factors for puncture-site complications. METHODS: This study investigated 327 consecutive cases of neuroendovascular surgery using a transfemoral procedure during a 2-year study period. Passive approximators (Angioseal [St Jude Medical, Saint Paul, MN] and Exoseal [Cordis Corporation, Miami, FL]) were mainly used in the first half and active approximators (Perclose [Abbot Vascular, Santa Clara, CA]) in the second. We compared groups and estimated risk factors for puncture-site complications. RESULTS: All procedures were successful. Comparing groups with and without puncture-site complications, use of passive approximators and ≥3 antithrombotic medications tended to be more frequent and distance from skin to femoral artery and body mass index tended to be lower in the group with complications without significance. The cutoff for femoral artery depth calculated from a receiver operating characteristic curve was 16.43 mm. Multivariate analysis revealed ≥3 antithrombotic medications (P = 0.002, OR 15.29, 95% CI 2.76-85.76) and passive approximator use in patients with femoral artery depth <16.43 mm (P < 0.001, OR 17.08, 95% CI 2.95-57.80) were significantly higher in the group with puncture-site complications. CONCLUSIONS: Passive approximator use in patients with shallow femoral artery depth increases puncture-site complications in neuroendovascular treatment.

Endovascular balloon usage in endoscopic third ventriculostomy for hydrocephalus during a national shortage: case series and technical note.

Endoscopic third ventriculostomy (ETV) is a well-established surgical technique for treating hydrocephalus. Many providers have transitioned to utilizing the specialized Neuroballoon for the stoma dilation in ETV; however, these devices are intermittently unavailable during supply chain shortages. We present the experience of employing cardiac angioplasty and neurovascular balloons as substitutes for the Neuroballoon in 3 patients. The scepter balloon (Microvention), priced at $1800 compared to the standard $300 Neuroballoon (Integra), proved effective, but its pliability presented technical challenges. The substantial cost differential compared to a Neuroballoon ($300) raises economic considerations. The Cardiac TREK balloon (Abbott) was similarly effective, while also being easier to manage endoscopically and cheaper at $158. These experiences support the viability of non-neuroendoscopic specialized balloons as alternatives for ETV dilation of the floor of tuber cinereum.

Machine Meets Brain: A Systematic Review of Effectiveness of Robotically Performed Cerebral Angiography Interventions.

BACKGROUND: Stroke is a leading cause of death in the United States, with significant economic and human costs. Early diagnosis and rapid treatment are critical for preventing stroke-related morbidity and mortality. However, accessibility to neurointerventional medical centers remains a challenge for many Americans, highlighting the need for innovative solutions to improve stroke management. METHODS: This systematic review adhered to the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines and included 5 medical databases to identify relevant studies on robotically assisted cerebral angiography (RCA). Studies focusing on in-human robotic intracranial cerebral angiography were included. A bias assessment was conducted using appropriate tools for randomized controlled trials (RCTs) and non-RCTs. RESULTS: A total of 7 studies met the inclusion criteria, with 1 RCT and 6 non-RCTs included in the analysis. Robotic systems such as CorPath GRX, Magellan robot, YDHB-NS01, VIR-2 (vascular interventional robot), and RobEnt were evaluated. The studies reported various success rates, procedure times, and complications associated with robotically assisted procedures. Overall, the robotic interventions demonstrated promising results in terms of safety and efficacy, with comparable outcomes to manual methods. Despite the promising findings, several limitations were identified, including technical issues with the robotic systems, the high costs, and limited long-term data. Future research should focus on standardizing protocols, conducting larger trials with longer follow-up periods, and assessing cost-effectiveness to determine the role of RCA in clinical practice. CONCLUSIONS: RCA shows potential as a valuable tool in neuroendovascular interventions. Addressing the technical challenges and conducting further research will be crucial to fully realize the clinical benefits of this innovative technology and improve patient outcomes in stroke management.

Spinal tumor embolization with Onyx: A systematic review and meta-analysis.

INTRODUCTION: Onyx embolization has emerged as a promising technique for spinal tumor embolization due to its high devascularization rate and low incidence of complications. OBJECTIVE: Evaluate the safety and efficacy of Onyx embolization in spinal tumor procedures. METHODS: Following the PRISMA guidelines, we conducted a systematic review and meta-analysis. To be included, the articles had to report specific outcomes of Onyx embolization for spinal tumors (complications, mortality, blood loss, tumor devascularization, or reduction in tumor blush). RESULTS: We selected 11 out of 2941 articles, encompassing 127 patients. Among them, no major complications or persistent neurological deficits were reported, and no deaths occurred as a result of the embolization procedure. Of the 63 patients with available data, two complications were observed: one infarct leading to transient neurological deficit and one clinically silent vessel perforation related to the microcatheter. Thus, the complication rate was 1% (95% confidence interval (CI): 0% to 6%). Blood loss during surgery ranged from 100 to 1500 mL (four studies). Complete tumor blush reduction was achieved in 52% of the cases (95% CI: 16% to 88%) across 32 patients. Three studies reported a median percentage of tumor devascularization of 91% (86.1% to 97.5%). CONCLUSION: Onyx embolization for spinal tumor procedures appears to be a safe technique, as evidenced by the absence of major complications or deaths. However, the determination of its efficacy remains challenging due to limited data availability and substantial heterogeneity across studies. These findings highlight the need for future research to address this knowledge gap and further validate our results.

Racial differences in P2Y12 inhibitor responsiveness in patients undergoing neuro-endovascular procedures: A cohort from the Middle East.

BACKGROUND: Data on P2Y12 inhibitors responsiveness from the middle east is scarce. We sought to investigate patient responsiveness to P2Y12 inhibitors within a cohort of major races that characterize the UAE population. The secondary objective was to assess risk factors for hyper and hypo-responsiveness in this population. METHODS: We conducted a cross-sectional study on adults who received either clopidogrel or ticagrelor treatments and had platelet responsiveness testing before undergoing neuro-endovascular interventions at our quaternary care hospital between March 2015 and April 2019. RESULTS: During the study period, 249 subjects met the inclusion criteria. Overall, 17.3 % were hyper-responsive and 25.7 % were hypo-responsive to P2Y12 inhibitors. When comparing between the P2Y12 inhibitors, rates of hyper-responsiveness were significantly higher to ticagrelor when compared to clopidogrel (11 versus 6 %, p = 0.02 respectively). Contrarily, hypo-responsiveness rates were significantly higher in clopidogrel treated patients compared to their ticagrelor treated counterparts (23 versus 2 %, p < .001 respectively). Patients of Middle-Eastern origin showed a significantly higher rate of hypo-responsiveness to both clopidogrel and ticagrelor when compared to other races (41.1 % and 26.7 %, P < 0.001 respectively). Asians showed the highest rates of hyper-responsiveness for both agents. Multivariate logistic regression analysis showed that proton pump inhibitors and statin combination, (OR: 6.39, 95 %CI [1.60, 25.392]), and Middle East vs. Indian subcontinent patients (OR: 4.67, 95 %CI [1.79-12.14]) were independent predictors of hypo-responsiveness to both P2Y12 inhibitors. CONCLUSION: This study demonstrated a high rate of hypo-responsiveness to P2Y12 inhibitors in a UAE cohort of patients undergoing neuro-endovascular procedures. In addition, therapeutic responsiveness to P2Y12 inhibitors varied markedly based on the racial background. Future larger studies are needed to evaluate genetic variations that may contribute to this rate of hypo-responsiveness in our population.

Assessment of Blood Loss during Neuroendovascular Procedures.

(1) Background: Neuroendovascular procedures have generally been considered to have minor or inconsequential blood loss. No study, however, has investigated this question. The purpose of this study is to quantify the blood loss associated with neuroendovascular procedures and identify predictors of blood loss, using hemoglobin change as a surrogate for blood loss. (2) Methods: A retrospective review of 200 consecutive endovascular procedures (diagnostic and therapeutic) at our institution from January 2020 to October 2020 was performed. Patients had to have pre- and post-operative hematocrit and hemoglobin levels recorded within 48 h of the procedure (with no intervening surgeries) for inclusion. (3) Results: The mean age of our cohort was 60.1 years and the male representation was 52.5%. The mean pre-operative hemoglobin/hematocrit was significantly lower among females compared to males (12.1/36.2 vs. 13.0/38.5, p = 0.003, p = 0.009). The mean hemoglobin decrease was 0.5 g/dL for diagnostic angiograms compared to 1.2 g/dL for endovascular interventions (p < 0.0001), and 1.0 g/dL for all procedures combined. In a multivariate linear regression analysis, pre-operative antiplatelet/anticoagulant use was associated with a statistically significant decrease in hemoglobin. (4) Conclusions: Our data support that blood loss from diagnostic angiograms is marginal. Blood loss in endovascular interventions, however, tends to be higher. Pre-operative blood antiplatelet/anticoagulant use and increasing age appear to increase bleeding risk and may require closer patient monitoring.

Feasibility of early radial artery occlusion recanalization and reuse through transradial access for neuroendovascular procedures.

BACKGROUND: Radial artery occlusion (RAO) remains a significant limitation of neuroendovascular procedures peformed through transradial access (TRA) when radial artery needs to be reused. Instances of early RAO recanalization to successfully complete neuroendovascular procedures have been rarely documented. MATERIALS AND METHODS: Documents and imaging data were extracted retrospectively for all patients who underwent TRA diagnostic angiography and neuroendovascular procedures in our center from June 2022 to February 2023. The patients with early RAO who required repeat TRA were included. RESULTS: A total of 46 patients underwent repeat TRA, and 13 consecutive patients who experienced early RAO after angiography as confirmed by ultrasonography were enrolled in this study. The occluded radial arteries were successfully recanalized, and subsequent neuroendovascular procedures were carried out successful. During an average follow-up time of 7.1 months, no patients exhibited symptomatic RAO, dissection, hematoma or pseudoaneurysm. CONCLUSIONS: Early RAO recanalization and reused for neuroendovascular procedures through TRA is feasible. A visually guided and stable puncture process plays a crucial role in successfully recanalizing early RAO.

Assessing the efficacy of VerifyNow platelet-function testing in predicting postoperative thromboembolic complications of neuroendovascular surgery: A systematic review and meta-analysis (part 1).

BACKGROUND: Despite the heavily debated use of routine platelet-function testing, the VerifyNow Platelet Reactivity Unit (PRU) assay has been increasingly adopted as standard of care for assessing risk of postoperative thromboembolic complications of neuroendovascular surgery. OBJECTIVE: We conducted a systematic review and meta-analysis to examine the relationship between platelet response and risk of ischemic events from neuroendovascular surgery, assess the efficacy of point-of-care platelet-function testing in predicting thromboembolic outcomes, and assess whether a clinically useful threshold for platelet response can be defined in order to standardize guidelines. METHODS: PubMed, Embase, and Scopus were searched. Following deduplication, articles were first screened for relevance by title and abstract, followed by full text. RESULTS: Of 735 resultant articles, 22 studies consisting of 3266 patients undergoing neuroendovascular intervention were included. Diagnoses included both intracranial and extracranial pathologies, of which 45.8% were treated with flow diversion, 16.4% with stent-assisted coil embolization, 15.8% with intracranial stenting, 12.0% with simple coil embolization, 3.4% with balloon-assisted coil embolization, 3.6% with extracranial stenting, and 3.0% with an alternate method. 54.5% (12/22) of studies determined platelet hyporesponse to be an independent predictor of postoperative thromboembolic complications, with 27.3% (6/22) of studies reporting a similar, but non-statistically significant trend. 18.2% (4/22) of studies found no relationship between platelet response and postoperative thromboembolic complications. The estimated clinical threshold for PRU to prevent thromboembolic complications varied greatly across studies (Range: > 144-295 PRU). Meta-analysis found platelet hyporesponse to have a 2.23-fold increased risk of thromboembolic complications compared to normoresponders (RR = 2.23, P = 0.03). CONCLUSION: While PRU demonstrates a significant predictive value for postoperative thromboembolic complications of neuroendovascular surgery, the target therapeutic threshold for minimizing ischemic events remains unclear. Further studies, such as large multicenter cohorts of the existing data, are needed to standardize guidelines.

Assessing the efficacy of VerifyNow platelet-function testing in predicting postoperative hemorrhagic complications of neuroendovascular surgery: A systematic review and meta-analysis (part 2).

BACKGROUND: Dual antiplatelet therapy is used to reduce the risk of thromboembolic complications in neuroendovascular surgery. However, the predictive utility of preoperative platelet-sensitivity testing for decreasing bleed risk in patients undergoing endovascular neurointervention remains unclear. OBJECTIVE: We conducted a systematic review and meta-analysis to illustrate the association between platelet response and risk of hemorrhagic complications from neuroendovascular surgery, examine the efficacy of the VerifyNow platelet reactivity unit (PRU) assay in predicting hemorrhagic outcomes, and assess whether a clinically useful threshold for platelet response can be defined to standardize guidelines. METHODS: PubMed, Embase, and Scopus were searched. Articles were screened for relevance by title and abstract, followed by full text. RESULTS: Of 735 resultant articles, 17 studies of 2084 patients undergoing neuroendovascular intervention were included. Diagnoses included both intracranial and extracranial pathologies, of which 37.8% were treated with flow diversion, 22.4% with stent-assisted coil embolization, 14.3% with intracranial stenting, 12.8% with simple coil embolization, 5.8% with balloon-assisted coil embolization, 2.0% with extracranial stenting, and 4.8% with an alternate method. Precisely, 52.9% (9 out of 17) of studies determined platelet hyperresponse to be an independent predictor of postoperative hemorrhagic complications, with 11.8% (2 out of 17) of studies reporting a similar but non-statistically significant trend. 35.3% (6 out of 17) of studies found no relationship between platelet response and postoperative hemorrhagic complications. The estimated clinical threshold for PRU to prevent hemorrhagic complications varied considerably across studies (range: <46-118 PRU). Meta-analysis found platelet hyperresponse to have more than a 3-fold increased risk of hemorrhagic complications compared to normoresponders (relative risk = 3.2, p = 0.001). CONCLUSION: Although this meta-analysis shows the predictive utility of the P2Y12 assay for postoperative hemorrhagic complications in neuroendovascular surgery, the optimal therapeutic threshold for minimizing bleeding risk is still uncertain. To better understand the utility of the P2Y12 assay in the perioperative period, further prospective research is needed.

Perioperative Antiplatelet Management in the Flow-Diverter Treatment for Unruptured Cerebral Aneurysms: A Single-Center, Retrospective Analysis.

BACKGROUND: Although periprocedural antiplatelet therapy for the treatment of unruptured intracranial aneurysms (UIAs) using flow-diverter stents (FDSs) is necessary to avoid thromboembolic complications, a definite antiplatelet therapy has not been established. We aimed to evaluate the safety and efficacy of periprocedural antiplatelet management in UIA treatment with FDS. METHODS: A single-center retrospective analysis of consecutive patients with UIAs treated with FDSs between September 2013 and January 2022 was conducted. Patients received dual antiplatelet therapy (DAPT) (aspirin and clopidogrel) for 14-day before and 3-6 months after FDS placement. Platelet aggregation was evaluated prior to treatment using light transmission aggregometry, which was classified into 3 grades; 1-3: promoted, 4-6: appropriate, and 7-9: non-responder, for adenosine diphosphate (ADP) and collagen. By this classification, the antiplatelet regimen was modified. Outcome included hemorrhagic and ischemic events. RESULTS: 193 patients with 200 UIAs underwent 213 FDSs placement. The median platelet aggregability grade before treatment was 5 for ADP and 4 for collagen. Antiplatelet therapy modification was performed in 62 patients (32.1%). The median postoperative DAPT duration was 94 days. Antiplatelet medicine-related hemorrhagic events occurred in 4 patients (2.1%) and ischemic events occurred in 6 patients (3.1%). These patients had no morbido-mortality. CONCLUSIONS: Periprocedural antiplatelet management based on the value of platelet aggregability was relatively safe and effective for treating UIA with FDS.

Transradial or Transulnar Long Sheath Access to the Brachial Artery Allows for Neuroendovascular Procedures in Patients with Radial or Ulnar Artery Occlusion.

BACKGROUND: Transradial access is an important tool for many neuroendovascular procedures. Occlusion of the radial or ulnar artery is not uncommon after transradial or transulnar access and can present a challenge for patients requiring repeat angiography. METHODS: Between March 2022 and June 2023, patients undergoing transradial or transulnar angiography who were found to have a radial artery occlusion or ulnar artery occlusion were identified. Repeat catheterization of the occluded artery was attempted using a 21-gauge single wall puncture needle and a 0.021-inch wire to traverse the occlusion and insert a 23-cm sheath into the brachial artery. RESULTS: A total of 25 patients undergoing 26 angiograms during the study period were found to have a radial artery occlusion or ulnar artery occlusion. Successful repeat catheterization of the occluded artery was achieved in 21 of 26 cases (80.7%). Outer diameter sheath size ranged from 5 Fr (0.0655 inch) to 8 Fr (0.1048 inch). No access complications were encountered. Number of prior angiograms, time since prior angiogram, and prior angiogram procedure time were associated with lower likelihood of successful access. CONCLUSIONS: Transradial or transulnar neuroangiography through an occluded radial or ulnar artery is safe and feasible by traversing the occlusion into the brachial artery with a 23-cm sheath. Repeat catheterization is most successful in patients with an arterial occlusion <6 months old. This technique is important in patients who have limited options for arterial access, avoiding access site complications inherent in transfemoral access, and in patients who specifically require radial or ulnar artery access.