Transradial approach for mechanical thrombectomy in anterior circulation large-vessel occlusion

Radial Versus Femoral Access for Mechanical Thrombectomy in Patients With Stroke: A Noninferiority Randomized Clinical Trial

BACKGROUND

Transfemoral access is predominantly used for mechanical thrombectomy in patients with stroke with a large vessel occlusion. Following the interventional cardiology guidelines, routine transradial access has been proposed as an alternative, although its safety and efficacy remain controversial. We aim to explore the noninferiority of radial access in terms of final recanalization.

METHODS

The study was an investigator-initiated, single-center, evaluator-blinded, noninferiority randomized clinical trial. Patients with stroke undergoing mechanical thrombectomy, with a patent femoral artery and a radial artery diameter ≥2.5 mm, were randomly assigned (1:1) to either transradial (60 patients) or transfemoral access (60 patients). The primary binary outcome was the successful recanalization (expanded Treatment in Cerebral Ischemia score, 2b-3) assigned by blinded evaluators. We established a noninferiority margin of -13.2%, considering an acceptable reduction of 15% in the expected recanalization rates.

RESULTS

From September 2021 to July 2023, 120 patients were randomly assigned and 116 (58 transradial access and 58 transfemoral access) with confirmed intracranial occlusion on the initial angiogram were included in the intention-to-treat analysis. Successful recanalization was achieved in 51 (87.9%) patients assigned to transfemoral access and in 56/58 (96.6%) patients assigned to transradial (adjusted 1 side risk difference [RD], -5.0% [95% CI, -6.61% to +13.1%]) showing noninferiority of transradial access. Median time from angiosuite arrival to first pass (femoral, 30 [interquartile range, 25-37] minutes versus radial: 41 [interquartile range, 33-62] minutes; P<0.001) and from angiosuite arrival to recanalization (femoral: 42 (IQR, 28-74) versus radial: 59.5 (IQR, 44-81) minutes; P<0.050) were longer in the transradial access group. Both groups presented 1 severe access complication and there was no difference in the rate of access conversion: transradial 7 (12.1%) versus transfemoral 5 (8.6%) (P=0.751).

CONCLUSIONS

Among patients who underwent mechanical thrombectomy, transradial access was noninferior to transfemoral access in terms of final recanalization. Procedural delays may favor transfemoral access as the default first-line approach.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT05225636.

A "Radial Ready" Tricoaxial Setup for Anterior Circulation Mechanical Thrombectomy: Technical Aspects and Preliminary Results

PURPOSE

Mechanical thrombectomy (MT) is the standard of care for acute ischemic stroke (AIS) due to large vessel occlusion (LVO). The choice of a transradial approach (TRA) for anterior circulation LVOs is still debatable; the use of a specific tricoaxial system could help mitigate numerous issues related to transradial MT.

MATERIALS AND METHODS

From November 2022 to November 2023, 22 patients underwent TRA-MT for anterior circulation LVOs, both as first-line and rescue from transfemoral approach (TFA) failure, with the same triaxial setup consisting of a 7F introducer sheath, 7F guide catheter, and aspiration catheters ranging from 5.5F to 5F in relation to the occlusion site. Choice of thrombectomy technique was at operator discretion. Patients' demographic data, clinical presentation, treatment details, complications, rate of crossover to TFA, successful revascularization (modified thrombolysis in cerebral infarction [mTICI] score ≥2b), and good clinical outcome at 3 months (modified Rankin scale [mRS] 0-2) were reported.

RESULTS

Of 20 patients selected, 10 (50%) had occlusion of M1 segment of middle cerebral artery (MCA), 6 (30%) of internal carotid artery (ICA) terminus, and 4 (20%) with M2 MCA occlusions; 12/20 (60%) were right-sided occlusions and 8/20 (40%) were left-sided. The mean National Institutes of Health Stroke Scale score was 9.25 at admission. Successful revascularization to mTICI 2b-3 was achieved in 18/20 patients (90%). Intracranial complications were reported in 2 (10%) patients. Rate of radial artery occlusion at 24 hours was 10,6%; no access-site haemorrhagic complications were reported. Symptomatic intracranial hemorrhage occurred in 2 (10%) patients. mRS score 0-2 at 3 months was 50%.

CONCLUSION

The high technical effectiveness and good safety profile of this specific tricoaxial setup for TRA-MT in AIS, even for large proximal LVOs, could constitute a viable alternative to TFA-MT in selected cases.

The Zoom RDL radial access system for neurointervention: An early single-center experience

BACKGROUND

The transradial approach (TRA) for neurointerventional procedures is increasingly being used given its technical feasibility and safety. However, catheter trackability and device deliverability are reported barriers to TRA adoption.

METHODS

This is the first report describing the technical feasibility and performance of using the Zoom RDL Radial Access System (Imperative Care, Inc., Campbell, CA) in 29 patients who underwent neurointerventional procedures from October 2022 to January 2023 in a single-center institution.

RESULTS

Mean age of the study population was 61.9±17.2 years, 79.3% were male (23/29), and 62.1% were black (18/29). The most common procedures were stroke thrombectomy (31.0%, 9/29) and aneurysm embolization (27.6%, 8/29). All the stroke thrombectomy procedures were successfully performed; first-pass effect rate (mTICI≥2 c in one pass) was achieved in 66.7% (6/9) of cases. We used TRA in 86.2% of cases (25/29), including distal radial/snuffbox access in 31.0% (9/29) of cases. The radial diameter was >2 mm for all cases. An intermediate/aspiration catheter was used in 89.7% (26/29) of cases. Access success was achieved in 89.7% of cases (26/29); two cases required conversion from TRA to transfemoral approach (6.9%) and one case required conversion to a different guide catheter (3.4%). There were no access site complications or other Zoom RDL-related complications. One intracerebral hemorrhage, and one procedure-related thrombus were observed.

CONCLUSIONS

The use of Zoom RDL Radial Access System is technically feasible and effective for complex neurointerventional procedures with low complication rates.

Transradial Access Failures During Neuroangiography for Patients With Moyamoya

BACKGROUND

Despite studies continuing to demonstrate the utility of transradial access (TRA) in neuroangiography, minimal data exist regarding predictors of TRA failure. Furthermore, although many patients with moyamoya disease/syndrome will require life-long angiographic evaluation, even less has been reported on the usage of TRA in this population.

OBJECTIVE

To perform a matched analysis at our high-volume moyamoya center to determine predictors of TRA failure in these patients.

METHODS

A total of 636 patients undergoing TRA for neuroangiography were identified from 2018 to 2020. Demographic and angiographic characteristics including radial artery spasm (RAS), radial anomalies, and access site conversion were compared between patients with moyamoya and the rest of the cohort. A 4:1 matched analysis, based on age and sex, was also performed to eliminate confounding variables.

RESULTS

Patients with moyamoya were younger (40 vs 57 years, P < .0001), had smaller radial diameters (1.9 vs 2.6 mm, P < .0001), more commonly had a high brachial bifurcation (25.9% vs 8.5%, P = .008), more frequently experienced clinically significant RAS (40% vs 8.4%, P < .0001), and more often required access site conversion (26.7% vs 7.8%, P = .002). Increasing age was associated with less TRA failures in patients with moyamoya (odds ratio = 0.918) but more failures in the rest of the cohort (odds ratio = 1.034). In the matched analysis, patients with moyamoya continued to experience more radial anomalies, RAS, and access site conversions.

CONCLUSION

Patients with moyamoya, when controlling for age and sex, have higher rates of TRA failure during neuroangiography. Increasing age in Moyamoya is inversely correlated with TRA failures suggesting that younger patients with moyamoya are at higher risk of extracranial arteriopathy.

Transradial Mechanical Thrombectomy Using a Radial-specific Neurointerventional Guiding Sheath for Anterior Circulation Large-Vessel Occlusions: Preliminary Experience and Literature Review

BACKGROUND

Transradial mechanical thrombectomy (MT) is increasingly used because it is associated with a low incidence of vascular access site complications. However, transradial carotid cannulation can be technically challenging to perform in patients with an unfavorable supra-aortic takeoff. In this study, the feasibility and safety of a new transradial MT system with a radial-specific neurointerventional guiding sheath-6F Simmons guiding sheath was evaluated-in patients with anterior circulation large-vessel occlusions. Additionally, a literature review was performed.

METHODS

We retrospectively analyzed data from our institutional database about consecutive patients who underwent transradial MT for anterior circulation large-vessel occlusion. After the 6F Simmons guiding sheath was engaged into the target common carotid artery, a triaxial system (Simmons guiding sheath/aspiration catheter/microcatheter), was established. MT using the continuous aspiration prior to intracranial vascular embolectomy technique was performed. Then, procedural success rate, successful revascularization, and procedure-related complications were assessed.

RESULTS

A total of 13 patients who had transradial MT were included in the analysis. All 13 patients underwent successful thrombectomy without catheter kinking or system instability, and 12 of them achieved successful revascularization (modified Thrombolysis in Cerebral Infarction score of ≥2b). No complications occurred.

CONCLUSIONS

To the best of our knowledge, this is the first case series on transradial MT using a radial-specific neurointerventional system for anterior circulation large-vessel occlusions. This method may increase the success rate of transradial MT. Based on our initial experience, transradial MT, using this system, was feasible and safe for anterior circulation large-vessel occlusions.

Availability of tracheal shift in the chest X-ray image as pre-treatment evaluation of mechanical thrombectomy

BACKGROUND

The use of mechanical thrombectomy (MT) for treatment of acute large vessel occlusion has recently increased. Prompt and timely guiding catheter (GC) induction is necessary to improve prognosis of MT and reduce the time for recanalization. However, difficulties in GC induction are encountered in some patients. This GC induction depends mainly on the aortic arch structure. Therefore, this study focused on assessing presence of tracheal shift on chest X-ray images as pre-treatment evaluation method for GC induction due to its wide availability as an indicator for status of the mediastinum.

METHODS

We retrospectively examined 33 patients who underwent MT at our facilities between April 2017 and March 2021. The patients were divided into two groups according to presence or absence of tracheal shift on chest X-ray images. Background characteristics and treatment courses in these two groups were compared.

RESULTS

Among 33 patients, tracheal shift was observed on the chest X-ray images of 14 patients. Furthermore, tracheal shift was positively correlated with the time of GC induction (32.9 min vs. 11.6 min, [p < 0.05]) and the female sex (p = 0.03). Additionally, tracheal shift exhibited correlations with multiple risk factors of atherosclerosis (p = 0.04).

CONCLUSIONS

In patients with tracheal shift, GC induction could be expectedly difficult. Therefore, advanced disinfection of the right upper arm and affected side of the neck during MT in preparation for changing an approach route is required.

Safety of Sheathless Transradial Balloon Guide Catheter Placement for Acute Stroke Thrombectomy

BACKGROUND

Transradial access has been described for mechanical thrombectomy in acute stroke, and proximal balloon occlusion has been shown to improve recanalization and outcomes. However, sheathed access requires a larger total catheter diameter at the access site. We aimed to characterize the safety of sheathless transradial balloon guide catheter use in acute stroke intervention.

METHODS

Consecutive patients who underwent sheathless right-sided transradial access for thrombectomy with a balloon guide catheter were identified in a prospectively collected dataset from 2019 to 2021. Demographics, procedure details, and short-term outcomes were collected and reported with descriptive statistics.

RESULTS

A total of 48 patients (20 women) with a mean age of 72.3 years were identified. Of patients, 56.3% had occlusions in the left-sided circulation; 35 (72.9%) had M1 occlusions, 7 (14.6%) had M2 occlusions, and 6 (12.5%) had internal carotid artery occlusions. Tissue plasminogen activator was administered to 16 (33.3%) patients. Five (10.4%) patients underwent intraprocedural carotid stenting. The cohort had successful reperfusion after a median of 1 (interquartile range: 1, 2) pass. Median time from access to recanalization was 31 (interquartile range: 25, 53) minutes. A postprocedural Thrombolysis In Cerebral Infarction score of ≥2b was achieved in 46 (95.8%) patients. Five patients had wrist access site hematomas. All hematomas resolved with warm compresses, and no further intervention was required.

CONCLUSIONS

Sheathless radial access using a balloon guide catheter may be safely performed for acute ischemic stroke with excellent radiographic outcomes. Further investigation is warranted to evaluate the comparative effectiveness of sheathless compared with sheathed transradial balloon guide access.

Feasibility and Safety of Flow Diversion in the Treatment of Intracranial Aneurysms via Transradial Approach: A Single-Arm Meta Analysis

Background

While studies have confirmed that flow diversion (FD) can treat intracranial aneurysms via transradial approach (TRA), it remains unclear whether their treatment ultimately impacts safety and feasibility. We aim to conduct a systematic review and meta-analysis assessing the safety and feasibility after FD treatment of intracranial aneurysms via TRA.

Methods

PubMed, EMBASE, and Web of Science were systematically reviewed. The primary outcomes were the success rate and the access-related complications of deploying FD via TRA. Meta-analysis was performed using a random or fixed effect model based on heterogeneity. And the publication bias was evaluated using a funnel plot. This study was registered with PROSPERO, number CRD42021244448.

Results

Data from 8 studies met inclusion criteria (250 non-duplicated patients). The success rate was 93% (95% confidence interval [CI] 0.86–0.98; I² = 61.05%; p = 0.01). The access-related complications rate was 1% (95% CI 0–0.03; I² = 0.00%; p < 0.01). The mainly access-related complications included radial artery spasm (85.7%) and radial artery occlusion (14.3%). The TRA convert to transfemoral approach (TFA) was 7% (95% CI 0.02–0.14; I² = 61.05%; p = 0.01).

Conclusions

Although TFA is still the main access for FD in the treatment of intracranial aneurysms, the TRA also has a higher success rate and lower access-related complications rate. With the improvement of future experience and equipment, the TRA may become the main access for FD which has more advantages. Future studies should design prospective, multicenter randomized controlled studies for long-term follow-up.

Mechanical Thrombectomy via Transradial Approach for Posterior Circulation Stroke: A Systematic Review and Meta-Analysis

Mechanical thrombectomy for acute ischemic stroke (AIS) is traditionally performed via transfemoral access. While the majority of AISs are due to anterior circulation large vessel occlusions (AC-LVO), we performed a systematic review and meta-analysis to examine the feasibility of and outcomes following a transradial artery access for posterior circulation large vessel occlusion (PC-LVO) strokes. A systematic literature review of the English language literature was conducted using PubMed, MEDLINE, and Embase as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Outcomes of interest included 90-day modified Rankin scale (mRS) 0-2, puncture to recanalization time, and thrombolysis in cerebral infarction (TICI) scores 2b/3 and 3. We calculated pooled event rates and their corresponding 95% confidence intervals (CI) for all outcomes. We included seven studies with 68 patients in our analysis. All patients underwent mechanical thrombectomy via transradial artery access for AIS due to PC-LVO. The pooled meantime of puncture to recanalization was 29.19 (95% CI=24.05 to 35.42) minutes. Successful recanalization (TICI2b/3) was achieved in 98.69% (95% CI=93.50 to 100) of patients and complete recanalization (TICI 3) in 52.16% (95% CI=34.18 to 79.60) of the patients. Overall, 56.84% (95% CI=41.26 to 78.30) of patients achieved mRS 0-2. Transradial artery access for mechanical thrombectomy for PC-LVO stroke displays early promise and feasibility, particularly regarding very high rates of successful recanalization and low puncture to recanalization time.

Transradial versus transfemoral access for acute stroke endovascular thrombectomy: a 4-year experience in a high-volume center

PURPOSE

To compare clinical outcomes and safety of transradial (TRA) versus transfemoral access (TFA) for endovascular mechanical thrombectomy in acute stroke patients.

METHODS

Retrospective analysis of 832 consecutive patients with acute stroke undergoing interventional thrombectomy using TRA (n = 64) or TFA (n = 768).

RESULTS

Direct TFA failures occurred in 36 patients, 18 of which underwent crossover TFA to TRA, while direct TRA failures occurred in 2 patients having both crossovers to TFA. Successful catheterization was achieved in 96.8% (62/64) and 95.3% (732/768) of patients undergoing direct TRA and direct TFA, respectively, without significant differences. The median (IQR) catheterization time was 10 (8-16) min in the direct TRA group and 15 (10-20) in the direct TFA group (P < 0.001). This difference was also significant in the subgroup of anterior circulation strokes and in patients younger and older than 80 years of age. The majority of procedures yielded thrombolysis in cerebral infarction grade 2b/2c/3 revascularization in patients undergoing direct TRA (88.5%) and direct TFA (90.8%), without statistically significant differences. The median (IQR) puncture to recanalization time was 37 (24-58) min for the direct TRA group and 42 (28-70) min for the direct TFA group. Significant differences in access site complications, symptomatic ICH, and mRS score 0-2 at 90 days between both TRA and TFA accesses were not found.

CONCLUSIONS

TRA is not inferior to TFA in the probability of catheterization, times of catheterization and revascularization, and other clinical outcomes for mechanical thrombectomy in acute stroke.

Systematic Review on Endovascular Access to Intracranial Arteries for Mechanical Thrombectomy in Acute Ischemic Stroke

PURPOSE

In acute ischemic stroke for large vessel occlusions, delayed or failed access to intracranial occlusions has a negative impact on procedural and clinical outcomes. The aim of this review is to identify and quantify access failures and challenges in mechanical thrombectomy.

METHODS

A systematic literature review of PubMed and Scopus databases from January 2014 to October 2020 was performed. Articles reporting consecutive patients were used to calculate a crude failure rate of femoral and alternative accesses.

RESULTS

A total of 50 articles met the inclusion criteria, totalling 12,838 interventions. Failure to access the occlusion through transfemoral access occurred in 4.4% of patients, most commonly due to challenging supra-aortic vessel anatomy, decreasing to 3.6% when all alternative access routes were attempted. Failed access from alternative routes (direct carotid, radial and brachial approaches) attempted first-line or after failed femoral attempt were reported in 7.3% of patients. The occurrence rate of potentially challenging features (anatomical, diseases or others) ranged from 4.7% to 47.4%, primarily impacting the access time, procedure time, recanalization and clinical outcomes.

CONCLUSION

Failure to access the occlusion is a significant contributor to failed recanalization, regardless of access routes. Challenging, but eventually successful access is also a relevant factor in procedural and clinical outcomes; however challenging access requires a universal definition to enable quantification, so that methods for procedural optimization can be critically assessed.

Lessons Learned After 760 Neurointerventions via the Upper Extremity Vasculature: Pearls and Pitfalls

BACKGROUND

The radial approach has been gaining more widespread use by neurointerventionalists fueled by data from the cardiology literature showing better safety and overall reduced morbidity.

OBJECTIVE

To present our institution's experience with the radial approach for neuroendovascular interventions in 614 consecutive patients who underwent a cumulative of 760 procedures.

METHODS

A retrospective analysis was performed and identified neuroendovascular procedures performed via the upper extremity vasculature access site.

RESULTS

Amongst 760 procedures, 34.2% (260) were therapeutic, and 65.7% (500) were nontherapeutic angiograms. Access sites were 71.5% (544) via a conventional radial artery, 27.8% (211) via a distal radial artery, 0.5% (4) via an ulnar artery, and 0.1% (1) via the brachial artery. Most of the procedures (96.9%) were performed via the right-sided (737), 2.9% (22) via the left-sided, and 0.1% (1) via a bilateral approach. Major access site complications occurred at a rate of 0.9% (7). The rate of transfemoral conversion was 4.7% (36). There was a statistically higher incidence of transfemoral conversion when repeat procedures were performed using the same access site. Also, there was no significant difference between nontherapeutic procedures performed using the right and left radial access, and conventional versus distal radial access. Procedural metrics improved after completion of 14 procedures, indicating a learning curve that should be surpassed by operators to reach optimal outcomes.

CONCLUSION

Radial artery catheterization is a safe and effective means of carrying out a wide range of neuroendovascular procedures associated with excellent clinical outcomes and an overall low rate of periprocedural complications.

Distal Transradial Artery Access for Neuroangiography and Neurointerventions : Pitfalls and Exploring the Boundaries

Introduction

The distal transradial approach (dTRA) is progressively gaining more clinical use in the fields of cardiology and other vascular interventions, as it offers a number of advantages compared to conventional radial approach (TRA). These include lower rates of vascular occlusion which permits preservation of the proximal radial artery for future procedures in the event of a distal occlusion.

Aim

To share the experience in the use of dTRA for neurointerventions, showing its advantages, pitfalls as well as sharing our optimized puncture and hemostatic ultrarapid compression protocols to improve the use of this vascular access.

Methods

A retrospective analysis of our experience of diagnostic and interventional procedures performed via dTRA using an optimized protocol for puncture and postpuncture compression of the dTRA was performed.

The rate of complications (hematoma and arterial dissection at puncture site) femoral crossover, and assessment of postprocedural stenosis/occlusion with the ultrarapid compression protocol were also assessed.

Results

From March 2019 to July 2020 a total of 100 distal radial procedures were carried out and 53 diagnostic angiograms (53%) and 47 interventional procedures (47%) were included in the analysis. We achieved a 96% technical success, with a femoral crossover requirement in 3 cases (3%), and one conventional TRA crossover due to puncture failure.

Of the patients 3 presented puncture site hematomas (3%) with no intervention required, 61 patients (61%) underwent the ultrarapid hemostasis protocol in association with a hemostatic pad. Ultrasound follow-up was performed in 20 patients (20%) at 1–2 months with 1 case of occlusion (5%) and 2 of radial stenosis (10%). In all 3 cases proximal radial artery remained patent.

Conclusion

The dTRA is a safe and feasible access route for angiography and neurointerventions. Using vasodilators prepuncture, we attained a variable increase in the vascular diameter facilitating puncture and reducing the risk of occlusion and vascular spasm.

A rapid deflation protocol for postpuncture hemostasis does not significantly increase the hematoma rate.

Direct carotid puncture for mechanical thrombectomy in acute ischemic stroke patients with prohibitive vascular access

OBJECTIVE

While the benefit of mechanical thrombectomy (MT) for patients with anterior circulation acute ischemic stroke with large-vessel occlusion (AIS-LVO) has been clearly established, difficult vascular access may make the intervention impossible or unduly prolonged. In this study, the authors evaluated safety as well as radiographic and functional outcomes in stroke patients treated with MT via direct carotid puncture (DCP) for prohibitive vascular access.

METHODS

The authors retrospectively studied patients from their prospective AIS-LVO database who underwent attempted MT between 2015 and 2018. Patients with prohibitive vascular access were divided into two groups: 1) aborted MT (abMT) after failed transfemoral access and 2) attempted MT via DCP. Functional outcome was assessed using the modified Rankin Scale at 3 months. Associations with outcome were analyzed using ordinal logistic regression.

RESULTS

Of 352 consecutive patients with anterior circulation AIS-LVO who underwent attempted MT, 37 patients (10.5%) were deemed to have prohibitive vascular access (mean age [± SD] 82 ± 11 years, mean National Institutes of Health Stroke Scale [NIHSS] score 17 ± 5, with females accounting for 75% of the patients). There were 20 patients in the DCP group and 17 in the abMT group. The two groups were well matched for the known predictors of clinical outcome: age, sex, and admission NIHSS score. Direct carotid access was successfully obtained in 19 of 20 patients. Successful reperfusion (thrombolysis in cerebral infarction score 2b or 3) was achieved in 16 (84%) of 19 patients in the DCP group. Carotid access complications included an inability to catheterize the carotid artery in 1 patient, neck hematomas in 4 patients, non-flow-limiting common carotid artery (CCA) dissections in 2 patients, and a delayed, fatal carotid blowout in 1 patient. The neck hematomas and non-flow-limiting CCA dissections did not require any subsequent interventions and remained clinically silent. Compared with the abMT group, patients in the DCP group had smaller infarct volumes (11 vs 48 ml, p = 0.04), a greater reduction in NIHSS score (-4 vs +2.9, p = 0.03), and better functional outcome (shift analysis for 3-month modified Rankin Scale score: adjusted OR 5.2, 95% CI 1.02-24.5; p = 0.048).

CONCLUSIONS

DCP for emergency MT in patients with anterior circulation AIS-LVO and prohibitive vascular access is safe and effective and is associated with higher recanalization rates, smaller infarct volumes, and improved functional outcome compared with patients with abMT after failed transfemoral access. DCP should be considered in this patient population.

Learning curves for transradial access versus transfemoral access in diagnostic cerebral angiography: a case series

BACKGROUND

The perception of a steep learning curve associated with transradial access has resulted in its limited adoption in neurointervention despite the demonstrated benefits, including decreased access-site complications.

OBJECTIVE

To compare learning curves of transradial versus transfemoral diagnostic cerebral angiograms obtained by five neurovascular fellows as primary operator.

METHODS

The first 100-150 consecutive transradial and transfemoral angiographic scans performed by each fellow between July 2017 and March 2020 were identified. Mean fluoroscopy time per artery injected (angiographic efficiency) was calculated as a marker of technical proficiency and compared for every 25 consecutive procedures performed (eg, 1-25, 26-50, 51-75).

RESULTS

We identified 1242 diagnostic angiograms, 607 transradial and 635 transfemoral. The radial cohort was older (64.3 years vs 62.3 years, p=0.01) and demonstrated better angiographic efficiency (3.4 min/vessel vs 3.7 min/vessel, p=0.03). For three fellows without previous endovascular experience, proficiency was obtained between 25 and 50 transfemoral angiograms. One fellow achieved proficiency after performing 25-50 transradial angiograms; and the two other fellows, in <25 transradial angiograms. The two fellows with previous experience had flattened learning curves for both access types. Two patients experienced transient neurologic symptoms postprocedure. Transradial angiograms were associated with significantly fewer access-site complications (3/607, 0.5% vs 22/635, 3.5%, p<0.01). Radial-to-femoral conversion occurred in 1.2% (7/607); femoral-to-radial conversion occurred in 0.3% (2/635). Over time, the proportion of transradial angiographic procedures increased.

CONCLUSION

Technical proficiency improved significantly over time for both access types, typically requiring between 25 and 50 diagnostic angiograms to achieve asymptomatic improvement in efficiency. Reduced access-site complications and decreased fluoroscopy time were benefits associated with transradial angiography.

Radial first or patient first: a case series and meta-analysis of transradial versus transfemoral access for acute ischemic stroke intervention

BACKGROUND

Few studies have compared technical success and effectiveness of transradial access (TRA) versus transfemoral access (TFA) for mechanical thrombectomy (MT) for acute ischemic stroke (AIS). We compared the two approaches for technical success, effectiveness, and outcomes.

METHODS

We retrospectively compared TRA with TFA for AIS MT at our institute. We additionally performed a systematic review and meta-analysis of studies describing the use of TRA alone or in comparison with TFA for MT. Primary outcomes included rate of successful reperfusion (thrombolysis in cerebral infarction (TICI) >2b), number of passes, access-site complications, and 3- month mortality and favorable functional outcomes (modified Rankin Scale (mRS) score 0-2).

RESULTS

A total of 222 consecutive patients (TRA=93, TFA=129) were included in our case series. The rate of successful reperfusion was significantly higher for the TFA cohort (91.4% vs 79.6%, P=0.01) with lower mean number of passes (1.8±1.2 vs 2.4±1.6, P=0.014). Three-month mortality in the TFA group was lower (22.1% vs 40.9% for the TRA cohort (P=0.004), with a higher rate of favorable functional outcomes (51.3% vs 34.1%, P=0.015). A meta-analysis of 10 studies showed significant heterogeneity in rates of successful reperfusion (57.1% to 95.6%, heterogeneity=67.55%, P=0.001). None of the previous comparative studies reported 3-month mortality and functional outcomes.

CONCLUSIONS

This case series demonstrate a higher successful reperfusion rate, fewer passes, lower 3-month mortality, and improved 3-month functional outcomes with TFA. The systematic review highlights the inadequacy of existing evidence. Prospective comparative studies are needed before a 'radial-first' approach can be adopted for stroke intervention.

A comparative study of transradial versus transfemoral approach for flow diversion

PURPOSE

Data in neurointerventional literature is extremely limited regarding the safety and efficacy of flow diversion using transradial access (TRA). We aim to demonstrate the safety and efficacy of intracranial aneurysm treatment with the Pipeline Embolization Device (PED) using TRA compared to transfemoral access (TFA).

METHODS

We conducted a retrospective analysis of a prospectively maintained database and identified 79 consecutive patients who underwent neuroendovascular embolization for cerebral aneurysms using the PED from April 2018 through October 2019. Patients were divided into 2 groups: TRA (32 patients) and TFA (47 patients). A comparative analysis was performed between the two groups.

RESULTS

There was no significant difference in postoperative intracranial hemorrhage (p>.99), symptomatic ischemic stroke (p=.512), access site complications (p=.268), or other complications (p=.512). However, there was a significant increase in overall complications (14.9% vs. 0.0%, p=.038) and procedure duration (71.4 min ± 31.2 vs. 58.5 ± 20.3, p=.018) in the TFA group. There was no significant difference in complete occlusion at latest follow-up (19/25, 76.0% vs. 35/40, 87.5%; p=.311), 6-month follow-up (17/23, 73.9% vs. 33/38, 86.8%; p=.303), or 12-month follow-up (8/8, 100.0% vs. 5/6, 83.3%; p=.429). There was also no significant difference in rate of retreatment (p>.99), morbidity (p=.512), mortality (p>.99), latest follow-up (p=.985), or loss of follow-up (p=.298).

CONCLUSIONS

The feasibility and efficacy of flow diversion with the PED via TRA for the treatment of intracranial aneurysms is comparable to TFA. Widespread adoption of this approach may be facilitated by improvements in device navigation and manipulation via radial-specific engineering.

CTA-Based Patient-Tailored Femoral or Radial Frontline Access Reduces the Rate of Catheterization Failure in Chronic Subdural Hematoma Embolization

BACKGROUND AND PURPOSE

Chronic subdural hematoma embolization, an apparently simple procedure, can prove to be challenging because of the advanced age of the target population. The aim of this study was to compare 2 arterial-access strategies, femoral versus patient-tailored CTA-based frontline access selection, in chronic subdural hematoma embolization procedures.

MATERIALS AND METHODS

This was a monocentric retrospective study. From the March 15, 2018, to the February 14, 2019 (period 1), frontline femoral access was used. Between February 15, 2019, and March 30, 2020 (period 2), the choice of the frontline access, femoral or radial, was based on the CTA recommended as part of the preoperative work-up during both above-mentioned periods. The primary end point was the rate of catheterization failure. The secondary end points were the rate of access site conversion and fluoroscopy duration.

RESULTS

During the study period, 124 patients (with 143 chronic subdural hematomas) underwent an embolization procedure (mean age, 74 [SD, 13] years). Forty-eight chronic subdural hematomas (43 patients) were included during period 1 and were compared with 95 chronic subdural hematomas (81 patients) during period 2. During the first period, 5/48 (10%) chronic subdural hematoma embolizations were aborted due to failed catheterization, significantly more than during period 2 (1/95, 1%; P = .009). The rates of femoral-to-radial (P = .55) and total conversion (P = .86) did not differ between the 2 periods. No significant difference was found regarding the duration of fluoroscopy (P = .62).

CONCLUSIONS

A CTA-based patient-tailored choice of frontline arterial access reduces the rate of catheterization failure in chronic subdural hematoma embolization procedures.

Early experience with a novel 088 long sheath in transradial neurointerventions

BACKGROUND

Transradial access (TRA) for neuroendovascular procedures has several clear benefits compared to transfemoral access. In this study, we report our initial experience with neuroendovascular procedures performed via transradial access using the novel Ballast 088 long sheath.

METHODS

We conducted a retrospective analysis and identified 91 consecutive patients who underwent neuroendovascular procedures via TRA using the Ballast 088 long sheath. Data collection was performed on indication for procedure, number of vessels selectively catheterized, fluoroscopy time, procedure duration, radiation exposure, failure of radial access and conversion to transfemoral access, periprocedural complications, and procedural outcomes.

RESULTS

Amongst 91 patients, the average age was 65.5 years ± 14.2 with 45 (49.5 %) female patients. 25 (27.5 %) patients underwent aneurysm treatment, 2 (2.2 %) AVM/AVF embolization, 28 (30.8 %) intracranial or extracranial stenting, 31 (34.1 %) stroke treatment, and 5 (5.5 %) underwent diagnostic angiogram. The mean number of target vessels catheterized was 1.07 ± 0.25, the mean procedure duration (minutes) was 96.5 ± 57.2, mean fluoroscopy time (minutes) was 21.9 ± 14.2, mean contrast dose (ml) was 112.7 ± 66.7, and mean radiation exposure (Gycm2) was 54.82 ± 41.37. The success rate of target vessel catheterization was 100 %. There were no complications resulting in long term sequelae. Access complications occurred in 1 (1.1 %) patients. Transfemoral conversion was required in 3 (3.3 %) patients.

CONCLUSIONS

The Ballast 088 long sheath is safe and effective for TRA in neuroendovascular procedures with a low rate of complications and conversion.

Similarities and Differences Between Primary Percutaneous Coronary Intervention and Mechanical Thrombectomy

Acute ischemic stroke is among the leading causes of mortality and disability worldwide. Since 2015, as was the case for primary percutaneous coronary intervention for acute myocardial infarction, catheter-based reperfusion via mechanical thrombectomy (MT) has become the gold-standard treatment for acute ischemic stroke caused by large-vessel occlusion. Despite that, only a fraction of the world's population currently would be able to undergo MT in time, mostly because of the scarcity of 24/7 coverage by neurointerventionalists to deal with this enormous burden. Interventional cardiologists have thus been considered a logical option to aid in combating this vast demand to diminish the burden of acute ischemic stroke. However, despite some seemingly evident similarities between primary percutaneous coronary intervention and MT, for interventional cardiologists to enter this new field, they must be well trained and fully aware of all the clinical, technical, and environmental differences between these two scenarios. The main objective of this state-of-the-art paper is to serve as an introductory and comprehensive guide to familiarize the interventional cardiology community with the most critical technical aspects of MT.

Anatomic Snuffbox (Distal Radial Artery) and Radial Artery Access for Treatment of Intracranial Aneurysms with FDA-Approved Flow Diverters

BACKGROUND AND PURPOSE

Transradial access for neurointerventional procedures has been proved a safer and more comfortable alternative to femoral artery access. We present our experience with transradial (distal radial/anatomic snuffbox and radial artery) access for treatment of intracranial aneurysms using all 3 FDA-approved flow diverters.

MATERIALS AND METHODS

This was a high-volume, dual-center, retrospective analysis of each institution's data base between June 2018 and June 2020 and a collection of all patients treated with flow diversion via transradial access. Patient demographic information and procedural and radiographic data were obtained.

RESULTS

Seventy-four patients were identified (64 female patients) with a mean age of 57.5 years with a total of 86 aneurysms. Most aneurysms were located in the anterior circulation (93%) and within the intracranial ICA (67.4%). The mean aneurysm size was 5.5 mm. Flow diverters placed included the Pipeline Embolization Device (Flex) (PED, n = 65), the Surpass Streamline Flow Diverter (n = 8), and the Flow-Redirection Endoluminal Device (FRED, n = 1). Transradial access was successful in all cases, but femoral crossover was required in 3 cases (4.1%) due to tortuous anatomy and inadequate support of the catheters in 2 cases and an inability to navigate to the target vessel in a patient with an aberrant right subclavian artery. All 71 other interventions were successfully performed via the transradial approach (95.9%). No access site complications were encountered. Asymptomatic radial artery occlusion was encountered in 1 case (3.7%).

CONCLUSIONS

Flow diverters can be successfully placed via the transradial approach with high technical success, low access site complications, and a low femoral crossover rate.

Adoption of the Transradial Approach for Neurointerventions: A National Survey of Current Practitioners

OBJECTIVES

The transradial approach (TRA) is technically feasible for both diagnostic and therapeutic neurointerventions. It improves patient comfort and is not associated with increased procedural complications when compared to the transfemoral approach (TFA). To date, no studies have looked at barriers to adoption of TRA in the neurointerventionalist community. This study aims to obtain neurointerventionalist perspectives on their adoption of TRA.

MATERIALS AND METHODS

Online survey distributed to neurointerventionalists.

RESULTS

A total of 55 neurointerventionalists, 52 of whom utilized TRA, responded to our survey. Overall, participants were not concerned about TRA's technical feasibility for diagnostic or therapeutic neurointerventions or about procedural complications. Most of our cohort adopted TRA due to its increased patient comfort and to reduce access site complications. In-institution interventionalists were strongly perceived to be the most effective method of teaching TRA when compared to other methods. Catheters and equipment issues were reported by about 30% of our cohort as a barrier to TRA adoption.

CONCLUSIONS

The neurointerventionalist community largely perceives TRA to be technically feasible and was not concerned about its procedural complications. In-person institutionalists are strongly perceived to be the most effective method of teaching the approach. A significant barrier to adoption seems to be related to catheters and equipment issues.

Radial Access for Neurointerventions

Transradial access (TRA) has become the standard approach for cardiac intervention, with a large body of evidence demonstrating a lower incidence of vascular complications, better patient experience and cost reduction. There has been increasing interest in using TRA both for diagnostic neuroangiography and for interventional neurovascular procedures. This aim of this article is to discuss the advantages and limitations of TRA for neurointerventions. General technical details, such as pre-procedure recommendations, prevention of spasm and occlusion, haemostasis protocols and distal TRA puncture, are also described, along with the specific technical details of TRA for aneurysm embolisation, stroke thrombectomy and other neurovascular interventions. TRA provides additional tools to the neurointerventionist and – with appropriate training – the whole spectrum of intervention procedures can be achieved using this approach.

Navigating radial artery loops in neurointerventions

BACKGROUND

Although studies continue to demonstrate lower complications in neurointerventions using transradial access (TRA) compared with transfemoral approaches, anatomic radial variants can be difficult to navigate and remain one of the frequent causes of access site conversion.

OBJECTIVE

To evaluate predictors of TRA failure in neuroendovascular patients with radial loops and suggest a protocol for managing these anomalies.

METHODS

A prospective collection of patients undergoing TRA at participating institutions from July 2018 to September 2020 was reviewed. Patients with a radial loop were identified. Patient demographics and procedural characteristics were evaluated to determine predictors of both TRA failure and successful reduction of the radial loop.

RESULTS

We identified 32 transradial neurointerventions in which patients had radial loops. Twenty-two (68.8%) were identified by diagnostic angiography, and the majority were performed for evaluation or treatment of an aneurysm (56.3%). TRA failure occurred in 13 (40.6%) of the cohort and happened more frequently in patients over 60 years of age (p=0.01) and those with recurrent radial artery diameters ≤2 mm (p=0.02). Of the 19 patients who had successful TRA, 12 (63.2%) procedures were performed through the recurrent radial artery.

CONCLUSION

Although radial loops are associated with high transradial failure rates, our results suggest that the presence of a loop is not an absolute contraindication to TRA. Therefore, we recommend attempting loop navigation using our protocol. Patient age, vascular tortuosity, and recurrent radial artery size should help dictate when to convert to an alternative access site.

Transradial versus transfemoral access for anterior circulation mechanical thrombectomy: analysis of 375 consecutive cases

OBJECTIVE

To compare transradial artery access (TRA) to the gold standard of transfemoral artery access (TFA) in mechanical thrombectomy (MT) for stroke caused by anterior circulation large vessel occlusion.

METHODS

The clinical outcomes, procedural speed, angiographic efficacy and safety of both techniques were analysed in 375 consecutive cases over an 18-month period in a high volume statewide neurointerventional service.

RESULTS

There was no significant difference in patient characteristics, stroke parameters, imaging techniques or intracranial techniques. The median time elapsed between CT scanning and reperfusion was 96.5 min (IQR 68-123) in the TFA group and 95 min (IQR 68-123) in the TRA group (p=0.456). Of 336 patients who were independent at presentation 58% (124/214) of the TFA group and 67% (82/122) of the TRA group had a modified Rankin score of 0-2 at 90-day follow-up (p=0.093). Cross-over from radial to femoral was 4.6% (4/130) compared with 1.6% cross-over from femoral to radial (4/245), but did not meet the predetermined level of statistical significance (OR 2.92, 95% CI 0.81 to 10.52), p=0.088) and did not impact median procedural speed. Adequate angiographic reperfusion, first pass reperfusion, embolisation to new territory and symptomatic intracranial haemorrhage were similar in both groups. There was a significant difference in major access site complications requiring an additional procedure. None of the TRA cases had a major access site complication but 6.5% (16/245) of the TFA cases did (p=0.003).

CONCLUSION

This study suggests that using TRA for anterior circulation MT is fast, efficacious, safe and not inferior to the gold standard of TFA.

Predictors of outcome after mechanical thrombectomy for acute ischemic stroke in patients aged ≥90 years

BACKGROUND

Mechanical thrombectomy (MT) has established its role as a first-line treatment of acute ischemic stroke due to large vessel occlusions (LVO). However, patients older than 85 or even 80 years of age are commonly excluded from large randomized controlled stroke studies as this group was found to be associated with significantly poorer clinical outcome and increased mortality compared to younger patients. The aim of this study was to evaluate clinical and procedural factors associated with clinical outcome and mortality among nonagenarians with acute ischemic stroke treated with mechanical thrombectomy.

MATERIALS AND METHODS

This retrospective, single-center study was conducted on 38 patients with LVO treated with MT. Clinical features including baseline results, radiological imaging, procedural details and outcome results were documented and evaluated. Recanalization was assessed according to the TICI score. The clinical condition was evaluated on admission (NIHSS) and after 3 months (mRS).

RESULTS

The rate of successful recanalization (TICI ≥2b) was 84.2 % (32/38). Symptomatic intracranial hemorrhage (sICH) was observed in 3 (7.9 %) patients. After 90 days, the mortality rate was 47.4 %. Favorable clinical outcome (mRs 0-2) was regained in 28.9 % of the patients (11/38). Poor clinical outcome (mRs<2) was observed in 9 patients (23.7 %).

CONCLUSION

Very elderly patients with LVO should not be excluded from MT even if prognosis for good clinical outcome in this age group remains low and the procedure is more challenging. Long-term outcome is predicted by stroke severity (baseline NIHSS and occluded vessel) and hospital arrival time.

Transradial access for thrombectomy in acute stroke: A systematic review and meta-analysis

OBJECTIVE

Transradial access has recently been gaining more popularity in various neurointerventional procedures. To this day, a systematic review and meta-analysis investigating the outcomes of transradial access for mechanical thrombectomy in acute stroke have not been performed.

METHODS

PubMed, Embase, and Scopus databases were systematically searched. Studies published in the last ten years reporting on the use of transradial access for acute stroke intervention were eligible. The DerSimonian-Laird random effects model was used, and the primary endpoints included puncture to reperfusion time, end mRS, TICI reperfusion, mortality, and access site complications.

RESULTS

A total of 515 records were identified. Fourteen observational studies reported on the use of radial access for thrombectomy, with 10 of these studies (n = 309) included in the meta-analysis. Mean puncture to reperfusion time associated with the transradial access was 46.864 ± 6.601 min. Favorable end mRS of ≤ 2 was reported in 37.1 % ± 7.3 % of patients. TICI ≥ 2B was achieved in 84.6 % ± 3.4 % of patients. All-cause mortality was observed in 9.3 % ± 4.8 % of patients. Transradial access had low complications with only 1.4 % ± 0.7 % of stroke cases. When the transradial studies were compared to the contemporary randomized clinical trials using the standard transfemoral access, no significant differences were found in all of these primary outcomes.

CONCLUSION

This meta-analysis study demonstrates that transradial access for mechanical thrombectomy in acute stroke may be a feasible and safe alternative. Future prospective studies are needed to validate these results.

Transradial approach and its variations for neurointerventional procedures: Literature review

Background:

The transfemoral approach (TFA) has been the standard in neuroradiology over the years. However, the transradial approach (TRA) and its variants offer several benefits over the TFA.

Methods:

Review of the literature about TRA and its variations. We present our results for different neurointerventional procedures at our institution between January 2018 and December 2019.

Results:

We wrote an educational review describing anatomical and technical aspects, advantages, and complications of this approach. In the past year we increased the percentage of neurointerventional procedures performed through radial or ulnar arteries.

Conclusion:

There are clearly proven benefits of employing a wrist approach in patients for neurointerventional procedures and its utilization should especially be considered on a daily basis.

Implementation of a radial long sheath protocol for radial artery spasm reduces access site conversions in neurointerventions

BACKGROUND

Many neurointerventionalists have transitioned to transradial access (TRA) as the preferred approach for neurointerventions as studies continue to demonstrate fewer access site complications than transfemoral access. However, radial artery spasm (RAS) remains one of the most commonly cited reasons for access site conversions. We discuss the benefits, techniques, and indications for using the long radial sheath in RAS and present our experience after implementing a protocol for routine use.

METHODS

A retrospective review of all patients undergoing neurointerventions via TRA at our institution from July 2018 to April 2020 was performed. In November 2019, we implemented a long radial sheath protocol to address RAS. Patient demographics, RAS rates, radial artery diameter, and access site conversions were compared before and after the introduction of the protocol.

RESULTS

747 diagnostic cerebral angiograms and neurointerventional procedures in which TRA was attempted as the primary access site were identified; 247 were performed after the introduction of the long radial sheath protocol. No significant differences in age, gender, procedure type, sheath sizes, and radial artery diameter were seen between the two cohorts. Radial anomalies and small radial diameters were more frequently seen in patients with RAS. Patients with clinically significant RAS more often required access site conversion (p<0.0001), and in our multivariable model use of the long sheath was the only covariate protective against radial failure (OR 0.061, 95% CI 0.007 to 0.517; p=0.0103).

CONCLUSION

In our experience, we have found that the use of long radial sheaths significantly reduces the need for access site conversions in patients with RAS during cerebral angiography and neurointerventions.

Safety and efficacy of the transbrachial approach for endovascular thrombectomy in patients with acute large vessel occlusion stroke

BACKGROUND

The transbrachial approach (TBA) is an alternative method to the transfemoral approach (TFA). We herein aimed to evaluate the safety and efficacy of the TBA for endovascular thrombectomy (EVT) in patients with acute large vessel occlusion stroke.

METHODS

We reviewed the records of 297 patients who had undergone EVT from January 2015 to July 2019. Eighteen patients who had undergone 19 procedures were included. Indications for arterial access, devices, recanalization rates, complication rates, and clinical outcomes were evaluated.

RESULTS

There were 15 and 4 cases of anterior and posterior circulation stroke, respectively. The mean patient age was 80.1 years. Eight patients were male. The median National Institutes of Health Stroke Scale score was 18. The total procedure duration tended to be longer when the TBA was used after failure of the TFA (n = 6, 32%, median: 60.5 min) than when the TBA was used as the first treatment approach (n = 13, 68%, median: 22 min). Optimal recanalization (a modified Thrombolysis in Cerebral Infarction score of 2b or 3) was achieved for 15 procedures. Local complications were observed in two cases: one with brachial artery pseudoaneurysm and another with brachial artery occlusion. Three patients with anterior circulation stroke exhibited good clinical outcomes (modified Rankin score ≤ 2) at 90 days. Symptomatic intracranial hemorrhage occurred in one patient. Mortality was noted in four patients.

CONCLUSION

The TBA for EVT is a suitable alternative when adoption of the TFA is difficult or impossible.

Direct puncture of the carotid artery as a bailout vascular access technique for mechanical thrombectomy in acute ischemic stroke-the revival of an old technique in a modern setting

Purpose

To describe our single-center experience of mechanical thrombectomy (MTE) via a direct carotid puncture (DCP) with regard to indication, time metrics, procedural details, as well as safety and efficacy aspects.

Methods

DCP thrombectomy cases performed at our center were retrospectively identified from a prospectively maintained institutional MTE database. Various patient (age, sex, stroke cause, comorbidities), clinical (NIHSS, mRS), imaging (occlusion site, ASPECT score), procedural (indication for DCP, time from DCP to reperfusion, materials used, technical nuances), and outcome data (NIHSS, mRS) were tabulated.

Results

Among 715 anterior circulation MTEs, 12 DCP-MTEs were identified and analyzed. Nine were left-sided M1 occlusions, one right-sided M1 occlusion, and two right-sided M2 occlusions. DCP was successfully carried out in 91.7%; TICI 2b/3-recanalization was achieved in 83.3% via direct lesional aspiration and/or stent-retrieval techniques. Median time from DCP to reperfusion was 23 min. Indications included futile transfemoral catheterization attempts of the cervical target vessels as well as iliac occlusive disease. Neck hematoma occurred in 2 patients, none of which required further therapy.

Conclusion

MTE via DCP in these highly selected patients was reasonably safe, fast, and efficient. It thus represents a valuable technical extension of MTE, especially in patients with difficult access.

Transradial access for diagnostic angiography and interventional neuroradiology procedures: A four-year single-center experience

PURPOSE

The objective of this study was to assess the efficacy and safety of transradial access for diagnostic angiography and interventional neuroradiology procedures.

METHODS

This was a retrospective analysis of a single-center experience based on 225 patients attended between August 2015 and October 2019, in which transradial access was used for diagnostic angiography and endovascular interventions. Ultrasound-guided access was done at the level of the forearm or anatomical or snuffbox (distal transradial access). Conventional forearm transradial access was done in 179 procedures (right, left and bilateral in 169, 5 and 5, respectively), while distal transradial access was done in 46 cases (41 right and 5 left). Primary outcome measures included successful catheterization, need to change access, or technical complications.

RESULTS

In the group of 131 diagnostic angiographies, the technique success rate was 100% to target the right vertebral artery, 97% for the right internal carotid, 93.5% for the left internal carotid, 82% for the left vertebral artery, and 100% for both common and external carotid arteries. All patients were discharged within 2-4 h after the procedure. A total of 94 interventional procedures were performed, including aneurysms in 39 cases, stroke in 34, and other procedures (carotid stents, arteriovenous malformations, carotid-cavernous fistula) in the remaining 21. The overall technical success in both diagnostic angiographies and interventional procedures was 97.7%. In four cases of diagnostic angiography and in 1 intervention, it was necessary to switch from transradial access to transfemoral access. Three cases of hematoma related to the access site were recorded.

CONCLUSIONS

In our experience, transradial access is an alternative approach for diagnostic angiography and neuro-interventions.

Transradial access for flow diversion of intracranial aneurysms: Case series

BACKGROUND

Transradial access for neurointerventions offers advantages of fewer access-site complications, reduced procedure time, and greater patient comfort over transfemoral access. Data about transradial access for flow diversion are limited. We share our early experience with transradial access for flow diversion in a relatively large case series.

METHODS

Consecutive patients who underwent Pipeline embolization device (Medtronic) deployment via transradial access were included in the study, irrespective of location and laterality of the intracranial aneurysm. The cases were performed between July 2016 and October 2019. Demographics, aneurysm characteristics, and procedure-related details (including catheter systems used) were recorded and statistically evaluated.

RESULTS

Thirty-five transradial flow diversion procedures were attempted in 32 patients, of which 33 procedures were successful. In two cases involving left common carotid artery and internal carotid artery access, guide catheter herniation into the aortic arch led to abandonment of transradial access in favor of transfemoral access. The most common aneurysm locations in the transradial access procedures were the posterior communicating artery (n = 7), ophthalmic artery (n = 7), and superior hypophyseal artery (n = 7). Most transradial access procedures (66.7%) were performed using a biaxial catheter system. 6-French Benchmark (Penumbra) and Phenom 27 (Medtronic) were the most commonly utilized guide- and microcatheters, respectively. One patient had intraprocedural subarachnoid hemorrhage. No access-site complications occurred.

CONCLUSION

This study demonstrates safety and feasibility of transradial access for Pipeline embolization device deployment and shows the versatility of this approach for different catheter systems. Tortuosity and acute angulation of the left common carotid artery and internal carotid artery were associated with approach failure.

The Neuro Radialist

Trans-radial approach (TRA) has been used in cardiac and peripheral interventional radiology practices for decades, because of safety and patient comfort. There is interest in TRA in the cerebrovascular field, with potential to replicate benefits over trans-femoral approach. TRA is technically more challenging and has a learning curve, which hinders its use as the first-line approach; however, as more neuro-interventionalists embrace TRA, techniques are being optimized simultaneously for supra-aortic vessel catheterization. This article describes advantages, patient selection, conventional and distal radial access, and detailed techniques of trans-radial catheterization for diagnostic angiography, as well as cerebrovascular interventions and its current limitations.

Direct Common Carotid Artery Puncture: Rescue Mechanical Thrombectomy Strategy in Acute Ischemic Stroke

PURPOSE

In a minority of cases, the transfemoral approach cannot be performed due to unfavorable anatomical barriers. In such cases, direct common carotid artery puncture (DCCAP) is an important alternative for rescue mechanical thrombectomy. The purpose of this study was to evaluate the efficacy and safety of DCCAP in patients with an unaccessible femoral route for mechanical thrombectomy.

MATERIALS AND METHODS

This is a retrospective study using data in the Turkish Interventional Neurology Database recorded between January 2015 and April 2019. Twenty-five acute stroke patients treated with DCCAP were analyzed in this study. Among 25 cases with carotid puncture, 4 cases were excluded due to an aborted thrombectomy attempt resulting from unsuccessful sheath placement.

RESULTS

Patients had a mean age of 69±12 years. The average National Institutes of Health Stroke Scale score was 16±4. Successful revascularization (modified Thrombolysis In Cerebral Infarction 2b-3) rate was 86% (18/21), and 90-day good functional outcome rate (modified Rankin Scale 0-2) was 38% (8/21).

CONCLUSION

DCCAP is a rescue alternative for patients with unfavorable access via the transfemoral route. Timely switching to DCCAP is crucial in these cases.

Mechanical Thrombectomy for Large Vessel Occlusion via the Transbrachial Approach: Case Series

Mechanical thrombectomy has become a standard treatment for acute ischemic stroke with large vessel occlusion. In aged patients, it is difficult to guide the catheter via the transfemoral approach due to vessel tortuosity and aortic elongation. We report our preliminary clinical experience using the transbrachial approach. Among the 119 patients who underwent thrombectomy from April 2018 to December 2019, a total of 5 patients were treated via the transbrachial approach. Clinical outcomes were retrospectively analyzed. Successful reperfusion was achieved in 4 out of 5 cases. There was 1 death due to symptomatic intracranial hemorrhage. One patient had a good outcome at discharge. There were no access-site complications associated with any of these cases. Transbrachial access for mechanical thrombectomy is feasible and can provide an alternative to the transfemoral approach.

Trans-Carotid and Trans-Radial Access for Mechanical Thrombectomy for Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

Objective We aim to demonstrate the safety and effectiveness of extra-femoral endovascular access for mechanical thrombectomy for acute ischemic stroke patients whose vascular anatomy precludes safe or maneuverable trans-femoral access. Methods Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to conduct a systematic review and meta-analysis with articles published until March 2018. The search protocol, including research questions and inclusion and exclusion criteria, were developed a priori. Our own institutional retrospective data were included in the cohort of case series. Results Eleven studies including 51 patients were included. Age ranged from 4th to 10th decade of life (average: 9.3rd decade) and 40.1% received IV tissue plasminogen activator. Initial National Institutes of Health Stroke Scale (NIHSS) score ranged from 1 to 36, (average: 17.6). Of the 51 patients, 39 (76%) patients suffered from anterior circulation large vessel occlusions versus 12 (24%) from posterior circulation occlusions. Site of access included 26 (51%) radial artery punctures, 23 (45%) direct percutaneous cervical carotid punctures, 1 brachial artery puncture, and 1 direct extradural vertebral artery puncture. Technical success was achieved in 43/51 (84%) of patients. The average modified Rankin Scale at discharge was 2.93 (n=26). There were no complications in 25 patients who underwent radial arterial access. Two (7.4%) of 27 cervical access patients developed hematoma. Conclusions Trans-carotid and trans-radial access for intervention in acute ischemic stroke is safe and effective. There may be instances in which these approaches should be considered first line before standard femoral approaches.

Access Through the Anatomical Snuffbox for Neuroendovascular Procedures: A Single Institution Series

BACKGROUND

Distal transradial catheterization in the anatomic snuffbox is an alternate route of access that has started to gain consideration for neuroendovascular procedures.

OBJECTIVE

To assess the feasibility and outcomes and present our institution's experience in performing neuroendovascular procedures via distal transradial access (dTRA).

METHODS

We conducted a retrospective analysis and identified 120 patients who underwent consecutive neuroendovascular procedures via dTRA in the anatomic snuffbox. Data collection was performed on indication for procedure, sheath size, number of vessels selectively catheterized, fluoroscopy time, procedure duration, radiation exposure, conversion to femoral approach, access site complication, and procedure success.

RESULTS

Of 120 patients with an average age of 54.7 yr ± 14.7, 73 (60.8%) underwent diagnostic angiograms, 38 (31.7%) underwent follow-up angiograms, and 9 (7.5%) underwent therapeutic procedures. The overall mean number of vessels catheterized was 2.5 ± 0.1 per procedure, the mean procedure time was 68.3 min ± 43.4, the mean fluoroscopy time was 10.8 min ± 7.6, the mean contrast dose was 70.6 mL ± 39.1, and the mean radiation exposure was 27 672.2 mGycm2 ± 42 728.4. Successfully completed therapeutic procedures included aneurysm 1 (0.8%), arteriovenous malformation (AVM)/arteriovenous fistula/carotid cavernous fistula 7 (5.8%), and 1 (0.8%) other treatment. Three patients (2.5%) required adjunct transfemoral endovenous access for AVM embolization. Two minor complications (1.67%) were a local wrist hematoma and a radial artery vasospasm without any sequelae.

CONCLUSION

Distal radial artery catheterization in the anatomic snuffbox is a safe and effective access site to perform neuroendovascular procedures. Complications and conversion rate are low making it a safe alternative.

Transition to Radial Approach for Neurovascular Procedures is Safe and Convenient: Characterization of a Learning Experience

BACKGROUND

The transradial access for endovascular procedures has become a popular access point of preference for both patients and for many neuro-endovascular practitioners.

OBJECTIVE

To describe a single-center experience on the transition to a radial-first approach for neurovascular procedures, focused on diagnostic angiographies, and to compare the differences in terms of length of procedure within the first 5 mo of its execution.

METHODS

We performed a retrospective review of a prospective maintained cerebrovascular registry at an academic institution within the United States, to identify the expected adoption curve required to transition to a transradial route first approach focused mainly on diagnostic procedures. The 5 mo of experience were divided into 4 quartiles evenly distributed in time. The primary outcome was the total length of procedure. Secondary outcomes were access failure, radiation dose, the usefulness of ultrasound assistance and complications.

RESULTS

A total of 121 transradial procedures were performed: 113 diagnostic angiographies (93%) and 8 therapeutic interventions (7%). We identified 6 access failures (5%) and 1 complication (1%). The mean length for diagnostic angiographies was 24 ± 10 min, and for therapeutic procedures was 58 ± 19 min. A multivariate regression analysis demonstrated a significant decrease in the total length of procedures after the first quartile.

CONCLUSION

The transradial route shows to be a safe and convenient approach. The total length of procedure starts decreasing as providers gain experience and become more confident with this route, as seen in our 5-mo experience.

Unfavorable Vascular Anatomy during Endovascular Treatment of Stroke: Challenges and Bailout Strategies

The benefit of mechanical thrombectomy (MT) in acute ischemic stroke (AIS) due to large vessel intracranial occlusions is directly related to the technical success of the procedures in achieving fast and complete reperfusion. While a precise definition of refractoriness is lacking in the literature, it may be considered when there is reperfusion failure, long procedural times, or high number of passes with the MT devices. Detailed knowledge about the causes for refractory MT in AIS is limited; however, it is most likely a multifaceted problem including factors related to the vascular anatomy and the underlying nature of the occlusive lesion amongst other factors. We aim to review the impact of several key unfavorable anatomical factors that may be encountered during endovascular AIS treatment and discuss potential bail-out strategies to these challenging situations.

Transradial approach for neurointerventions: a systematic review of the literature

Background

Despite the recent increase in the number of publications on diagnostic cerebral angiograms using transradial access (TRA), there have been relatively few regarding TRA for neurointerventional cases. Questions of feasibility and safety may still exist among physicians considering TRA for neurointerventional procedures.

Methods

A systematic literature review was performed following PRISMA guidelines. Three online databases (MedLine via PubMed, Scopus and Embase) were searched for articles published between January 2000 and December 2019. Search terms included “Transradial access”, “Radial Access”, “Radial artery” AND “Neurointerventions". The reference lists of selected articles and pertinent available non-systematic analysis were reviewed for other potential citations. Primary outcomes measured were access site complications and crossover rates.

Results

Twenty-one studies (n=1342 patients) were included in this review. Two of the studies were prospective while the remaining 19 were retrospective. Six studies (n=616 patients) included TRA carotid stenting only. The rest of the studies included treatment for cerebral aneurysms (n=423), mechanical thrombectomy (n=127), tumor embolization (n=22), and other indications (n=154) such as angioplasty and stenting for vertebrobasilar stenosis, balloon test occlusion, embolization of dural arteriovenous fistula and arteriovenous malformation, chemotherapeutic drug delivery, intra-arterial thrombolysis, and arterial access during a venous stenting procedure. Two (0.15%) major complications and 37 (2.75%) minor complications were reported. Sixty-four (4.77%) patients crossed over to transfemoral access for completion of the procedure. Seven (0.52%) patients crossed over due to access failure and 57 (4.24%) patients crossed over to TFA due to inability to cannulate the target vessel.

Conclusion

This systematic review demonstrates that TRA has a relatively low rate of access site complications and crossovers. With increasing familiarity, development of TRA-specific neuroendovascular devices, and the continued reports of its success in the literature, TRA is expected to become more widely used by neurointerventionalists.

Transradial Approach as the Primary Vascular Access with a 6-Fr Simmons Guiding Sheath for Anterior Circulation Interventions: A Single-Center Case Series of 130 Consecutive Patients

OBJECTIVE

In coronary intervention, the transradial approach (TRA) is increasingly used as the primary vascular access because of its numerous advantages over the transfemoral approach. However, in neurointerventions, conventional TRA with a straight-shaped guiding system is used as an alternative vascular access because transradial carotid cannulation can be technically challenging for right common carotid artery (CCA) lesions with steep angulation to the right subclavian artery or left CCA lesions with a nonbovine origin. The purpose of the present study was to evaluate the feasibility and safety of TRA as the primary vascular access with a pre-shaped Simmons guiding sheath for anterior circulation interventions.

METHODS

Between June 2018 and September 2019, 130 consecutive patients (75 carotid artery stenting and 55 cerebral aneurysm coiling cases) who underwent TRA as the primary vascular access were included in this study. A 6-Fr Simmons guiding sheath was introduced into the target CCA by selecting a cannulation technique based on preprocedural image assessment. We retrospectively analyzed the carotid cannulation success, procedural success, and periprocedural or vascular access site complications.

RESULTS

Carotid cannulation (69 right CCA, 6 left CCA with a bovine origin, and 55 left CCA with a nonbovine origin) and the subsequent procedure were successfully performed for all 130 patients without periprocedural or vascular access site complications.

CONCLUSIONS

TRA with a 6-Fr Simmons guiding sheath for anterior circulation interventions is highly successful and safe for all target CCAs and aortic arch types. This method can be utilized as the primary vascular access for anterior circulation interventions.