Endovascular clot removal in small and tortuous arteries: a case series.

Acute limb ischemia (ALI) due to arterial thromboembolic occlusion is a critical emergency in vascular medicine, requiring attention for rapid diagnosis and intervention, to prevent limb loss and major amputation, which is associated with patient disability in the long term. Traditionally, surgical embolectomy has been used for the treatment of ALI. Endovascular treatment of ALI traditionally involved catheter-directed thrombolysis. This option, however, poses some limitations, including an increased risk for access site and systemic bleeding complications, especially in patients with high bleeding risk. Therefore, in the last decades, several devices have been developed and tested for the mechanical endovascular treatment of ALI. Such devices involve either rotational thrombectomy or continuous thrombus aspiration. While rotational thrombectomy is limited in rather large arteries due to the risk of dissection and perforation in arteries <3 mm, continuous thrombus aspiration can be applied in smaller vessels and tortuous anatomies. In our case series we present a minimal-invasive endovascular approach for the treatment of two patients with ALI due to thrombotic occlusion of tortious and small diameter arteries. Minimal-invasive mechanical thrombectomy using the Penumbra Aspiration System emerged as a successful alternative to surgical embolectomy, enabling prompt treatment and with a short hospital stay for both patients. Our article therefore highlights the use of continuous thrombus aspiration in small diameter vessels and tortuous anatomies, which may represent a contraindication for the use of rotational thrombectomy. In addition, this technique may be applied even in patients with higher bleeding risk since additional lysis is not necessary in patients, where complete thrombus removal can be achieved by this device.

Feasibility, efficacy, and safety of mechanical thrombectomy via sheathless transradial access as a first-line strategy: A case series.

OBJECTIVE: Although mechanical thrombectomy (MT) is primarily performed via transfemoral access (TFA), transradial access (TRA) is a potential alternative in older patients or those with tortuous vessels. However, the small radial artery diameter restricts the use of large-bore balloon guides and aspiration catheters, a limitation that may be overcome using the sheathless technique. Thus, we aimed to explore the feasibility, efficacy, and safety of sheathless TRA-MT as a first-line treatment approach for acute ischemic stroke. METHODS: This single-center retrospective case series included patients who underwent TRA-MT as first-line treatment between September 2020 and June 2023. Per our MT protocol, TRA was not the first-line approach in cases of left anterior circulation lesions with a type 3 aortic arch. We evaluated treatment effectiveness based on the successful recanalization rate, puncture-to-recanalization time, and modified first-pass effect; access route effectiveness based on the puncture-to-first-pass time and switch-to-TFA rate; and procedure safety based on procedure-related and severe puncture site complications. RESULTS: Sheathless 8-F guide catheters were used in 68 % and large-bore aspiration catheters in 70 % of the procedures. Successful recanalization was achieved in 98 % of the patients, with a modified first-pass effect in 54 % of them. The median puncture-to-first-pass and puncture-to-recanalization times were 20.5 and 33 min, respectively. The rate of procedure-related complications was low (4 %), with no severe puncture site complications. CONCLUSION: Sheathless TRA-MT enabled the use of large-bore guide and aspiration catheters, providing a swift approach to the target and satisfactory outcomes, and might be an effective first-line treatment for acute ischemic stroke.

Percutaneous pulmonary aspiration thrombectomy in an adolescent fontan patient using a large-bore system.

We describe the safe and effective percutaneous pulmonary thrombectomy in an 18-year-old female with a Fontan circulation using the FlowTriever® device (Inari Medical®, Irvine, US). Aspiration thrombectomy of both pulmonary arteries was performed using 24 and 16 F FlowTriever® catheters retrieving large amounts of thrombus material resulting in near total angiographic recanalization.

Hepatic Artery Thrombectomy after Orthotopic Liver Transplantation: A Stent Retriever and/or Aspiration-Guided Catheter Approach.

Retransplantation has been the primary treatment for hepatic artery thrombosis (HAT) in patients with orthotopic liver transplant (OLT); however, because of scarcity of grafts, endovascular revascularization via mechanical thrombectomy offers an alternative to retransplantation should it provide similar long-term benefits. Data regarding a series of 8 patients with hepatic artery thrombectomies across 10 procedures (1 early HAT and 9 late HAT) utilizing stent retriever and/or suction catheter were collected. All had technically successful restoration of flow with stent placement of the anastomotic stenosis in 8 cases. Two patients required reintervention for HAT at 18 and 701 days after primary intervention, with the first dying from liver failure but with a patent hepatic artery on explant. One case had a procedure-related adverse event, hepatic artery dissection, Society of Interventional Radiology (SIR) adverse event classification of 2. Technical success was achieved in all procedures, demonstrating promise in effectively treating HAT in patients with OLT.

Safety and efficacy of stent retrievers plus contact aspiration in patients with acute ischaemic anterior circulation stroke and positive susceptibility vessel sign in France (VECTOR): a randomised, single-blind trial.

BACKGROUND: Positive susceptibility vessel sign (SVS) in patients with acute ischaemic stroke has been associated with friable red blood cell-rich clots and more effective recanalisation using stent retrievers versus contact aspiration. We compared the safety and efficacy of stent retrievers plus contact aspiration (combined technique) versus contact aspiration alone as the first-line thrombectomy technique in patients with acute ischaemic anterior circulation stroke and SVS-positive occlusions. METHODS: Adaptive Endovascular Strategy to the Clot MRI in Large Intracranial Vessel Occlusion (VECTOR) was a prospective, randomised, open-label study with blinded evaluation. Patients with SVS-positive anterior circulation occlusions on pretreatment MRI and arterial puncture within 24 h of symptom onset were enrolled from 22 centres in France. A centralised web-based method was used by interventional neuroradiologists for dynamic randomisation by minimisation. Patients were randomly assigned 1:1 to the combined technique or contact aspiration alone. The primary outcome was expanded Thrombolysis in Cerebral Infarction (eTICI) grade 2c or 3 reperfusion after three or fewer passes on post-treatment angiogram, adjudicated by a blinded independent central imaging core laboratory. The intention-to-treat population was used to assess the primary and secondary outcomes. This trial is registered with ClinicalTrials.gov (NCT04139486) and is complete. FINDINGS: Between Nov 26, 2019, and Feb 14, 2022, 526 patients were enrolled, of whom 521 constituted the intention-to-treat population (combined technique, n=263; contact aspiration alone, n=258). The median age of participants was 74·9 years (IQR 64·4-83·3); 284 (55%) were female and 237 (45%) male. The primary outcome did not differ significantly between groups (152 [58%] of 263 patients for the combined technique vs 135 [52%] of 258 for contact aspiration; odds ratio [OR] 1·27; 95% CI 0·88-1·83; p=0·19). Procedure-related adverse events occurred in 32 (12%) of 263 patients in the combined technique group and 27 (11%) of 257 in the contact aspiration group (OR 1·14; 0·65-2·00; p=0·65). The most common adverse event was intracerebral haemorrhage (146 [56%] of 259 patients for the combined technique vs 123 [49%] of 251 for contact aspiration; OR 1·32; 0·91-1·90; p=0·13). All-cause mortality at 3 months occurred in 57 (23%) of 251 patients in the combined technique group and 48 (19%) of 247 in the contact aspiration group (OR 1·19; 0·76-1·86; p=0·45), none of which was treatment-related. INTERPRETATION: The results of the VECTOR trial do not show superiority of the combined stent retriever plus contact aspiration technique over contact aspiration alone in patients with SVS-positive occlusion with respect to achieving eTICI 2c-3 within three passes. These findings support the use of either the combined technique or contact aspiration alone as the initial thrombectomy strategy in patients with acute anterior circulation stroke with SVS on pretreatment MRI. FUNDING: Cerenovus.

Autonomous navigation of catheters and guidewires in mechanical thrombectomy using inverse reinforcement learning.

PURPOSE: Autonomous navigation of catheters and guidewires can enhance endovascular surgery safety and efficacy, reducing procedure times and operator radiation exposure. Integrating tele-operated robotics could widen access to time-sensitive emergency procedures like mechanical thrombectomy (MT). Reinforcement learning (RL) shows potential in endovascular navigation, yet its application encounters challenges without a reward signal. This study explores the viability of autonomous guidewire navigation in MT vasculature using inverse reinforcement learning (IRL) to leverage expert demonstrations. METHODS: Employing the Simulation Open Framework Architecture (SOFA), this study established a simulation-based training and evaluation environment for MT navigation. We used IRL to infer reward functions from expert behaviour when navigating a guidewire and catheter. We utilized the soft actor-critic algorithm to train models with various reward functions and compared their performance in silico. RESULTS: We demonstrated feasibility of navigation using IRL. When evaluating single- versus dual-device (i.e. guidewire versus catheter and guidewire) tracking, both methods achieved high success rates of 95% and 96%, respectively. Dual tracking, however, utilized both devices mimicking an expert. A success rate of 100% and procedure time of 22.6 s were obtained when training with a reward function obtained through 'reward shaping'. This outperformed a dense reward function (96%, 24.9 s) and an IRL-derived reward function (48%, 59.2 s). CONCLUSIONS: We have contributed to the advancement of autonomous endovascular intervention navigation, particularly MT, by effectively employing IRL based on demonstrator expertise. The results underscore the potential of using reward shaping to efficiently train models, offering a promising avenue for enhancing the accessibility and precision of MT procedures. We envisage that future research can extend our methodology to diverse anatomical structures to enhance generalizability.

Antegrade and Retrograde Approaches with a Mechanical Thrombectomy Device for the Treatment of Acute Lower Limb Deep Vein Thrombosis.

OBJECTIVE: To examine the efficacy of antegrade and retrograde approaches with the AngioJet thrombectomy device for the treatment of acute lower limb deep vein thrombosis (DVT) and to evaluate the necessity of filter placement. METHODS: The clinical data of patients with acute lower limb DVT treated with the AngioJet device from January 2021 to June 2023 were retrospectively analyzed. The patients were divided into the antegrade and retrograde treatment groups according to the surgical approach and the direction of valve opening. The thrombosis interception rate of the filter, incidence of pulmonary embolism (PE), thrombectomy effectiveness, venous obstruction rate, and thrombosis recurrence rate of each treatment group were evaluated. In addition, factors affecting patency were analyzed. RESULTS: AngioJet was employed for 84 patients with acute lower limb DVT, treating a total of 88 limbs. The thrombosis interception rate of the filter was 35.7% (30 patients). The incidence of new PE or PE exacerbation was 6.0% (5 patients), and a filter retrieval rate of 97.6% (82 patients) was detected. Thrombus removal of grade III occurred in 35 (64.8%) of the 54 limbs (61.4%) in the antegrade treatment group versus 13 (38.2%) of the 34 limbs (38.6%) in the retrograde treatment group (P < 0.05). At 3 months, venous patency and bleeding events involved 52 (96.3%) and 4 (7.4%) limbs in the antegrade treatment group, respectively, versus 29 (85.3%) and 2 (5.9%) in the retrograde treatment group, respectively (P > 0.05). Regression analysis was performed to determine factors that may affect 3-month patency in both groups. Statistically significant linear relationships were found between 3-month patency and thrombus removal rate [odds ratio [OR] = 0.546 (0.326, 0.916)], thrombus formation time [OR = 1.018 (1.002, 1.036)], and preoperative thrombosis score [OR = 1.012 (1.002, 1.022)] in the antegrade treatment group, as well as thrombus removal rate [0.473 (0.229, 0.977)] in the retrograde treatment group. In regression analysis of factors affecting patency in both groups and the venous clinical severity score/Villalta score, a statistically significant linear relationship was found between thrombus formation time and the venous clinical severity score in the antegrade treatment group [0.576 (0.467, 0.710)]. CONCLUSIONS: Both antegrade and retrograde approaches are safe and effective for the treatment of acute lower limb DVT. There are no differences in 3-month deep vein patency and post-thrombotic syndrome (PTS) incidence rates. Individuals with acute lower limb DVT are at high risk of thrombus shedding after treatment with AngioJet thrombectomy, and placement of a vena cava filter (VCF) is recommended for effective interception.

The Safety and Efficacy of ZelanteDVT™ Catheter Rheolytic Thrombectomy in the Treatment of Patients with Iliac Vein Stent Thrombosis.

BACKGROUND: To examine the safety and efficacy of ZelanteDVT™ catheter rheolytic thrombectomy in the treatment of patients with iliac vein stent thrombosis. METHODS: A retrospective analysis method was conducted by means of collecting the data of 32 patients who had completed the treatment of iliac vein stent thrombosis with ZelanteDVT catheter rheolytic thrombectomy from March 2019 to March 2023. Data on clinical characteristics, technical success, clinical success, complications, and early follow-up were analyzed. RESULTS: The technical success rates were 100%, intraoperatively, in which 22 cases were improved to thrombus clearance Grade II (50-90%), 10 were Grade III (>90%). There were 21 cases treated with subsequent catheter-directed thrombolysis, and the average urokinase administration of (120.90 ± 29.63)∗10ˆ4 units. The clinical success rates were 100% and the swelling of the affected limbs were significantly improved, a significant difference in the pre/postoperative between-thigh circumference difference [(5.16 ± 1.08) vs. (1.75 ± 0.84), P < 0.000]. The pre/postoperative Venous Clinical Severity Score was [(12.94 ± 1.70) vs. (7.44 ± 1.31), P < 0.000]. No serious complications occurred during the perioperative period. The postoperative and 12-month stent patency rate was 100.00% (32/32) and 71.88% (23/32), respectively. CONCLUSIONS: The ZelanteDVT catheter rheolytic thrombectomy seems to have a promising application prospect for the treatment of patients with iliac vein stent thrombosis.

Current Approaches and Methods to Understand Acute Ischemic Stroke Treatment Using Aspiration Thrombectomy.

Acute ischemic stroke occurs when a blood clot occludes a cerebral artery. Mechanical interventions, primarily stent retrievers and aspiration thrombectomy, are used currently for removing the occluding clot and restoring blood flow. Aspiration involves using a long catheter to traverse the cerebral vasculature to reach the blood clot, followed by application of suction through the catheter bore. Aspiration is also used in conjunction with other techniques such as stent retrievers and balloon guide catheters. Despite the wide use of aspiration, our physical understanding of the process and the causes of the failure of aspiration to retrieve cerebral clots in certain scenarios is not well understood. Experimental and computational studies can help develop the capability to provide deeper insights into the procedure and enable development of new devices and more effective treatment methods. We recapitulate the aspiration-based thrombectomy techniques in clinical practice and provide a perspective of existing engineering methods for aspiration. We articulate the current knowledge gap in the understanding of aspiration and highlight possible directions for future engineering studies to bridge this gap, help clinical translation of engineering studies, and develop new patient-specific stroke therapy.

Combining Novel Thrombectomy Devices for Intracardiac Mass Extraction: The Kong and Godzilla of Mass Extraction.

Transcatheter extraction of an intracardiac mass is a newer approach that may lead to nonsurgical treatment of complex cardiac masses. We present a case in which thrombectomy devices were combined to extract a right atrial mass, which highlights new frontiers in the treatment of complex transcatheter mass extraction. The combined use of two transcatheter thrombectomy devices (Kong and Godzilla) may provide a powerful addition to the existing armamentarium.

Comparison of Outcomes between Stent Retriever Combined with Contact Aspiration and Contact Aspiration Alone in Patients without Hyperdense Artery Sign/Susceptibility Vessel Sign.

PURPOSE: To examine the relationship between hyperdense artery sign (HAS)/susceptibility vessel sign (SVS) and thrombus composition and evaluate the effect of HAS/SVS status on the association between first-line thrombectomy techniques and outcomes in patients with acute anterior circulation large vessel occlusion (LVO). MATERIALS AND METHODS: From January 2018 to June 2021, 103 consecutive patients with acute anterior circulation LVO (75 [63.1%] men; median age, 66 years) who underwent thrombectomy and for whom the removed clot was available for histological analyses were retrospectively reviewed. The presence of HAS and SVS was assessed on unenhanced computed tomography (CT) and susceptibility-weighted imaging, respectively. Association of first-line thrombectomy techniques (stent retriever [SR] combined with contact aspiration [CA] vs CA alone) with outcomes was assessed according to HAS/SVS status. RESULTS: Among the included patients, 55 (53.4%) were HAS/SVS-negative, and 69 (67.0%) underwent first-line SR + CA. Higher relative densities of fibrin/platelets (0.56 vs 0.51; P < .001) and lower relative densities of erythrocytes (0.32 vs 0.42; P < .001) were observed in HAS/SVS-negative patients compared with HAS/SVS-positive patients. First-line SR + CA was associated with reduced odds of distal embolization (adjusted odds ratio, 0.18; 95% CI, 0.04-0.83; P = .027) and a more favorable 90-day functional outcome (adjusted odds ratio, 5.29; 95% CI, 1.06-26.34; P = .042) in HAS/SVS-negative patients and a longer recanalization time (53 vs 25 minutes; P = .025) and higher risk of subarachnoid hemorrhage (24.2% vs 0%; P = .044) in HAS/SVS-positive patients. CONCLUSIONS: Absence of HAS/SVS may indicate a higher density of fibrin/platelets in the thrombus, and first-line SR + CA yielded superior functional outcomes than CA alone in patients with acute LVO without HAS/SVS.

Clinical, Functional, and Quality-of-Life Outcomes after Computer Assisted Vacuum Thrombectomy for Pulmonary Embolism: Interim Analysis of the STRIKE-PE Study.

PURPOSE: To report the first interim analysis of the STRIKE-PE study, evaluating the safety and effectiveness of computer assisted vaccum thrombectomy (CAVT) for the treatment of acute pulmonary embolism (PE). MATERIALS AND METHODS: This prospective, international, multicenter study will enroll 600 adult patients with acute PE of ≤14 days and a right ventricle (RV)-to-left ventricle (LV) ratio of ≥0.9 who receive first-line endovascular treatment with CAVT using the Indigo Aspiration System (Penumbra, Alameda, California). Primary endpoints are change in RV/LV ratio and incidence of composite major adverse events (MAEs) within 48 hours. Secondary endpoints include functional and quality-of-life (QoL) assessments. RESULTS: The first 150 consecutive patients were treated with 12F catheter CAVT. Mean age was 61.3 years, 54.7% were men, 94.7% presented with intermediate-risk PE, and 5.3% presented with high-risk PE. Median thrombectomy and procedure times were 33.5 minutes and 70.0 minutes, respectively, resulting in a mean reduction in systolic pulmonary artery pressure of 16.3% (P < .001). Mean RV/LV ratio decreased from 1.39 to 1.01 at 48 hours, a 25.7% reduction (P < .001). Four (2.7%) patients experienced a composite MAE within 48 hours. At 90-day follow-up, patients exhibited statistically significant improvements in the Borg dyspnea scale score and QoL measures, and the New York Heart Association class distribution returned to that reported before the index PE. CONCLUSIONS: Interim results from the STRIKE-PE study demonstrate a significant reduction in pulmonary artery pressure and RV/LV ratio, a median thrombectomy time of 33.5 minutes, a composite MAE rate of 2.7%, and significant improvements in 90-day functional and QoL outcomes.

Percutaneous Mechanical Thrombectomy Using the AcoStream Thrombus Aspiration System for Acute Superior Mesenteric Artery Embolism.

BACKGROUND: This study was performed to summarize our experience in treating acute superior mesenteric artery embolism (SMAE) by percutaneous mechanical thrombectomy (PMT). METHODS: Between January 2023 and October 2023, 18 patients presenting with acute mesenteric ischemia were admitted to our center, including 11 cases of SMAE, 3 cases of superior mesenteric artery thrombosis, and 4 cases of superior mesenteric vein thrombosis. We retrospectively reviewed 8 patients (4 males and 4 females; range, 51-79 years; mean, 62.50 ± 9.67 years) who underwent treatment of acute SMAE using the AcoStream system. The patients had no obvious evidence of intestinal necrosis as shown by peritoneal puncture or computed tomography. Thrombectomy was performed on the superior mesenteric artery (SMA) using an 8F AcoStream thrombus aspiration system (Acotec, China). The demographics, risk factors, therapeutic effect, complications, mortality, and follow-up of the study population were assessed. RESULTS: The technical success rate was 100%. After 1-3 passes (2.38 ± 0.92) and aspiration thrombectomy, complete thrombus removal was achieved in 7 (87.50%) patients. One patient received an adjunctive catheter-directed thrombolysis due to partial thrombus removal. Thrombolysis was conducted for 2 days, resulting in complete resolution of the thrombus. The other 7 patients did not receive adjunctive endovascular intervention due to complete thrombus removal and no residual stenosis. No distal embolization or device-related complications were noted during the procedure. After the procedure, sufficient clinical improvement was seen in 6 patients within 1-2 days. Two patients showed no significant improvement of their symptoms. Laparotomy was performed on day 1 and day 2 after thrombectomy in patients 3 and 7, respectively. Intestinal necrosis was diagnosed operatively and intestinal resection was performed. All patients were discharged 6-15 days (9.50 ± 3.07) after admission without perioperative complication or death. The mean follow-up period was 5.00 ± 3.30 months (range, 1-10 months), and the follow-up rate was 100%. During the follow-up, all patients remained symptom-free. Computed tomography angiography images showed good flow in the trunk and branches of the SMA in all patients. CONCLUSIONS: PMT using the AcoStream system is a minimally invasive, safe, and effective technique for acute SMAE. Early application of PMT can achieve immediate revascularization of the SMA and have the potential advantage of avoiding laparotomy or reducing the extension of enterectomy, as it could theoretically restore intestinal perfusion in less time than open revascularization. If the symptoms do not improve after PMT, exploratory laparotomy should be scheduled as soon as possible. Further studies are necessary on this field to confirm these findings.

Catheter Interventions for Pulmonary Embolism: Mechanical Thrombectomy Versus Thrombolytics.

Pulmonary embolism is a debilitating and potentially life-threatening disease characterized by high mortality and long-term adverse outcomes. Traditional treatment options are fraught with serious bleeding risks and incomplete thrombus removal, necessitating the development of innovative treatment strategies. While new interventional approaches offer promising potential for improved outcomes with fewer serious complications, their rapid development and need for more comparative clinical evidence makes it challenging for physicians to select the optimal treatment for each patient among the many options. This review summarizes the current published clinical data for both traditional treatments and more recent interventional approaches indicated for pulmonary embolism. While published studies thus far suggest that these newer interventional devices offer safe and effective options, more data is needed to understand their impact relative to the standard of care. The studies in progress that are anticipated to provide needed evidence are reviewed here since they will be critical for helping physicians make informed treatment choices and potentially driving necessary guideline changes.

Fabrication of Shape Memory Polymer Endovascular Thrombectomy Device for Treating Ischemic Stroke.

Stroke is the second result for death and ischemic stroke constitutes most of all stroke cases. Ischemic stroke takes place when blood clot or embolus blocks cerebral vessel and interrupts blood flow, which often leads to brain damage, permanent disability, or death. There is a 4.5-h (golden hour) treatment window to restore blood flow prior to permanent neurological impairment results. Current stroke treatments consist mechanical system or thrombolytic drug therapy to disrupt or dissolve thrombus. Promising method for stroke treatment is mechanical retrieving of thrombi employing device deployed endovascularly. Advent of smart materials has led to research fabrication of several minimally invasive endovascular devices that take advantage of new materials capabilities. One of these capabilities is shape memory, is capability of material to store temporary form, then activate to primary shape as subjected to stimuli. Shape memory polymers (SMPs) are employed as good materials for thrombectomy device fabrication. Therefore, current review presents thrombectomy device development and fabrication with SMPs. Design, performance, limitations, and in vitro or in vivo clinical results of SMP-based thrombectomy devices are identified. Review also sheds light on SMP's future outlook and recommendations for thrombectomy device application, opening a new era for advanced materials in materials science.

Efficacy and Safety of a New Delivery Assist Catheter with a Flexible, Spindle-Shaped Shaft in Mechanical Thrombectomy.

OBJECTIVE: Large-bore aspiration catheters (ACs) are used successfully in mechanical thrombectomy (MT). However, tortuous access routes prevent device navigation because of the ledge effect. The AXS Offset Delivery Assist Catheter is designed to reduce the ledge effect. The purpose of this study was to evaluate whether the Offset affects AC navigation compared with standard inner microcatheters in MT. METHODS: We retrospectively investigated 75 MTs for anterior circulation occlusion between January 2018 and May 2022 at our hospital. All MTs were performed using an AC, and 2 types of inner microcatheter (Offset or 0.021-0.027-inch standard microcatheter) were chosen randomly during AC navigation. The patients' characteristics, MT techniques, angiographic findings, and clinical outcomes were compared between the Offset and standard group (Non-Offset). The puncture to first pass of the lesion time was investigated to compare the characteristics of the inner catheters. RESULTS: The Offset group comprised 12 patients versus 63 in the Non-Offset group. Although most baseline clinical characteristics and outcomes were similar between the groups, the puncture to first pass of the lesion time was significantly shorter in the Offset versus Non-Offset group (31 ± 10 vs. 46 ± 24 minutes, respectively; P = 0.032). In the Offset group, all stent retrievers were deployed via the Offset. One artery dissection and 8 symptomatic intracranial hemorrhages occurred in the Non-Offset group; no complications occurred in the Offset group. CONCLUSIONS: The AXS Offset delivery assist catheter permitted faster and safer navigation of various ACs to the occlusions compared with standard delivery microcatheters in MT.

Comparison of 4 mm-sized and 3 mm-sized Stent Retrievers in Mechanical Thrombectomy for M2 Occlusion.

INTRODUCTION: A stent retriever (SR) is widely used in mechanical thrombectomy (MT) for M2 segment occlusion. However, the suitable size of SR in M2 occlusion remains unclear. Therefore, we aimed to compare 4 mm-sized SR with 3 mm-sized SR in M2 occlusion. METHODS: Patients who underwent MT with SR for M2 occlusion were dichotomized into 4×20 mm SR and 3×20 mm SR groups. Then, 1:1 propensity score matching was performed. The M2 segment was divided into proximal and distal segments according to the occlusion site. Subgroup analysis was then performed for each cohort. RESULTS: A total of 111 patients were enrolled, with 4×20 mm SR and 3×20 mm SR applied in 72 (64.9%) and 39 (35.1%) cases, respectively. In propensity score matching, mean number of stent passages for reperfusion was significantly lower in the 4×20 mm SR group than in the 3×20 mm SR group (1.5 ± 0.8 vs. 2.1 ± 1.1; p = 0.004). First-pass reperfusion (FPR) was more highly achieved in the 4×20 mm SR group than in the 3×20 mm SR group (52.6% vs. 42.1%; p = 0.007). In both proximal and distal occlusion cohorts, the 4 mm SR group showed lower mean number of SR passage (p = 0.004 and p = 0.003, respectively) and higher FPR rate than the 3 mm SR group (p = 0.003 and p = 0.007, respectively). CONCLUSION: In MT for M2 occlusion, 4×20 mm SR enables an effective procedure with lesser SR passage for reperfusion and a higher rate of FPR than 3×20 mm SR.

Modeling Robotic-Assisted Mechanical Thrombectomy Procedures with the CorPath GRX Robot: The Core-Flow Study.

BACKGROUND AND PURPOSE: Endovascular robotic devices may enable experienced neurointerventionalists to remotely perform endovascular thrombectomy. This study aimed to assess the feasibility, safety, and efficacy of robot-assisted endovascular thrombectomy compared with manual procedures by operators with varying levels of experience, using a 3D printed neurovascular model. MATERIALS AND METHODS: M1 MCA occlusions were simulated in a 3D printed neurovascular model, linked to a CorPath GRX robot in a biplane angiography suite. Four interventionalists performed manual endovascular thrombectomy (n = 45) and robot-assisted endovascular thrombectomy (n = 37) procedures. The outcomes included first-pass recanalization (TICI 2c-3), the number and size of generated distal emboli, and procedural length. RESULTS: A total of 82 experimental endovascular thrombectomies were conducted. A nonsignificant trend favoring the robot-assisted endovascular thrombectomy was observed in terms of final recanalization (89.2% versus manual endovascular thrombectomy, 71.1%; P = .083). There were no differences in total mean emboli count (16.54 [SD, 15.15] versus 15.16 [SD, 16.43]; P = .303). However, a higher mean count of emboli of > 1 mm was observed in the robot-assisted endovascular thrombectomy group (1.08 [SD, 1.00] versus 0.49 [SD, 0.84]; P = .001) compared with manual endovascular thrombectomy. The mean procedural length was longer in robot-assisted endovascular thrombectomy (6.43 [SD, 1.71] minutes versus 3.98 [SD, 1.84] minutes; P < .001). Among established neurointerventionalists, previous experience with robotic procedures did not influence recanalization (95.8% were considered experienced; 76.9% were considered novices; P = .225). CONCLUSIONS: In a 3D printed neurovascular model, robot-assisted endovascular thrombectomy has the potential to achieve recanalization rates comparable with those of manual endovascular thrombectomy within competitive procedural times. Optimization of the procedural setup is still required before implementation in clinical practice.