The transradial approach (TRA) is a less invasive alternative for carotid artery stenting (CAS). However, limited device availability has restricted its application, and reports on balloon guide catheters (BGCs) in TRA are scarce. This study reports the initial experience with sheathless 8Fr BGC in CAS via TRA.

We retrospectively analyzed cases of CAS performed with a sheathless 8Fr Optimo BGC (Tokai Medical Products) via TRA from April 2023 to November 2024. Patient demographics, procedural details, and outcomes were evaluated. The primary efficacy endpoint was the technical success rate, while the primary safety endpoint was a composite of major access-related complications, stroke, myocardial infarction, and death within 30 days.

A total of 30 cases were included (median age 77 years; 90% male). Symptomatic lesions were present in 42%, with a median stenosis rate of 79%, and 63% involved the right carotid artery. Sheathless BGC insertion and navigation succeeded in 29 cases (97%), with one case (3%) requiring conversion to brachial access due to radial artery spasm. Balloon inflation for flow control and device stabilization was performed in 23 cases (77%). CAS was successful in all cases, with no major complications or adverse events.

Our experience suggests that the sheathless 8Fr BGC is safe and feasible for CAS via TRA. This approach preserves the minimally invasive nature of TRA while improving device stability and potentially reducing embolic risk. Further development of TRA-specific low-profile devices may enhance procedural outcomes and broaden adoption in neurointervention.

Background and purposeThe transradial (TR) approach is an alternative to the traditional transfemoral (TF) approach for extracranial carotid artery stenting (eCAS). A successful eCAS may be contingent on the geometry of the great vessels. We aimed to analyze the vessel geometry to identify predictors for successful stent placement, enabling tailored approaches.Materials and methodsMulticenter retrospective data was collected from the electronic health record of patients who underwent eCAS from January 2018 to December 2022. Geometric parameters for great vessels were measured using computed tomography angiography (CTA) or magnetic resonance angiography (MRA). A successful approach was defined as completing eCAS without conversion. We performed a geometric analysis of features correlated with complications and successful completion of eCAS.Results1346 patients underwent TF (1081) and TR (265) eCAS. Conversion from TR to TF occurred in 44 cases (17%). Three TF cases required conversion. Complication rates did not differ between approaches (P = .773), but converting to TF had significantly higher Category 1 complications (P < .001). A smaller angle of origin of the left common carotid artery (A3) correlated with increased complications (P = .039), particularly with angles <90°, peaking at 50°. No other geometric features predicted the success.ConclusionBoth TR and TF stenting can be safely performed for carotid disease, but the angle of the left carotid artery origin predicted an increased risk of complications. No other aortic arch types or great vessel geometry predicted complications. Conversion from TR to TF predicted increased stroke, ICH, and MI.

The femoral artery is the preferred access route for neurointerventions. The transfemoral approach (TFA) offers advantages such as a large diameter and easy access. However, it also entails disadvantages such as patient discomfort and high risk of complications. Following the initial report of coronary angiography using the transradial approach (TRA) in 1989, cardiologists discovered the advantages of TRA over the TFA and gradually replaced it with the TRA. In 1997, Matsumoto et al. used the TRA for cerebral angiography and neurointervention. Thereafter, the adoption of TRA for neurointervention gradually increased and good outcomes were reported. However, despite these developments, the adoption rate of TRA is relatively low. We reviewed the relevant studies to increase the accessibility of TRA for neurointerventionists.

This study aimed to evaluate the safety and effectiveness of transbrachial access (TBA) and transradial access (TRA) compared to transfemoral access (TFA) for large-bore neuro stenting (≥7 F).

From January 2019 to January 2024, 4752 patients received large-bore neuro stenting in our center. The primary outcomes were procedural metrics. Safety outcomes were significant access site complications, including substantial hematoma, pseudoaneurysm, artery occlusion, and complications requiring treatment (medicine, intervention, or surgery). After propensity score matching with a ratio of 1:1:2 (TBA: TRA: TFA), adjusting for age, gender, aortic arch type, and neuro stenting as covariates, outcomes were compared between groups.

46 TBA, 46 TRA and 92 TFA patients were enrolled. The mean age was 67.8 ± 11.2 years, comprising 127 (69.0%) carotid artery stenting and 57 (31.0%) vertebral artery stenting. The rates of technical success (TBA: 100%, TRA: 95.7%, TFA: 100%) and significant access site complications (TBA: 4.3%, TRA: 6.5%, TFA: 1.1%) were comparable between the groups (P > 0.05). Compared to TFA, the TRA cohort exhibited significant delays in angiosuite arrival to puncture time (14 vs. 8 min, P = 0.039), puncture to angiography completion time (19 vs. 11 min, P = 0.027), and procedural duration (42 vs. 29 min, P = 0.031). There were no substantial differences in procedural time metrics between TBA (10, 14, and 31 min, respectively) and TFA.

TBA and TRA as the primary access for large-bore neuro stenting are safe and effective. Procedural delays in TRA may favor TBA as the first-line alternative access to TFA.

Objective: Carotid artery stenting (CAS) has traditionally been performed using the transfemoral approach (TFA). Recently, the transradial approach (TRA) has gained attention for its lower invasiveness and reduced complication risk. This study compares outcomes between two access strategy timeframes, TFA-first and TRA-first, to evaluate how this shift influences outcomes in a real-world setting. Methods: A retrospective analysis of 85 CAS procedures was conducted at our institution from October 2018 to September 2024, categorizing them into TFA-first (n = 42) and TRA-first (n = 43) periods. The primary endpoint was access-related complications and 30-day perioperative events, including stroke, myocardial infarction, and mortality. The secondary endpoints included target lesion access success rate, frequency of access route conversions, procedural time, and hospital length of stay. Results: Baseline characteristics, including age, sex, symptomatic status, stenosis severity, plaque characteristics, and anatomical considerations, were comparable between groups. In the TFA-first period, 88% of procedures utilized TFA, and TRA was not used at all, while the remaining 12% employed the transbrachial approach (TBA). In the TRA-first period, 23% of procedures employed TFA, 60% utilized TRA, and 16% relied on TBA (p < 0.01). Both groups achieved a similar rate of target lesion access success (98% each) with only one conversion per group. The primary endpoint was significantly lower in the TRA-first group (0%) compared to the TFA-first group (10%, p = 0.04), primarily due to reduced access-site complications. Additionally, the median hospital stay was shorter in the TRA-first group at 6 days compared to 10 days (p = 0.02). Conclusions: Adopting a TRA-first strategy over TFA in CAS leads to better outcomes by improving access-site safety and reducing hospital stays. Developing TRA-specific devices could further expand the applicability of TRA in CAS.

Carotid artery stenting (CAS) through transradial access (TRA) is emerging as an alternative to carotid endarterectomy. However, the current evidence base is limited, mainly comprising single-center studies.

This systematic review and meta-analysis aim to assess the safety and effectiveness of TRA for CAS, providing evidence to support clinical decisions.

We conducted searches on PUBMED, Cochrane Library, Embase, and Web of Science databases, including studies on TRA for CAS. Studies with fewer than 20 patients, non-primary outcomes, and non-full-text articles were excluded.

We analyzed 14 studies involving 1,166 patients who underwent CAS via TRA. Procedural success rate was high in 13 studies, with a 95% rate (95% CI; 92%-98%). Crossover to TFA access was observed in 12 studies at 6% (95% CI: 3%-9%). Transradial access failure was reported in four studies, with a rate of 0% (95% CI: 0%-0%). Cannulation failure resulted in a rate of 4% (95% CI: 2%-7%). Asymptomatic radial artery occlusion (ARAO) occurred at a rate of 2% based on eight studies (95% CI: 0%-5%). Forearm hematoma was reported in 10 studies, with an occurrence of 1% (95% CI: 0%-2%). Cerebral vascular attacks (CAV) within 30 days were assessed in 13 studies, indicating a 2% occurrence (95% CI: 1%-2%).

The findings suggest that TRA for CAS yields promising outcomes with high success rates and low complication rates. Further research should focus on randomized controlled trials and long-term outcomes to validate and extend findings.

There is an increasing number of studies on the transradial approach (TRA) for carotid artery stenting. We aimed to summarize the published data on TRA vs the transfemoral approach (TFA). We searched Science Direct, Embase, PubMed, and Web of Science databases for the relevant literature. Primary outcomes included surgical success and cardiovascular and cerebrovascular complication rates; secondary outcomes included the rates of vascular access-related and other complications. We also compared the crossover rate, success rate, and complications between TRA and TFA carotid stenting. This is the first such meta-analysis regarding TRA and TFA. Twenty studies on TRA carotid stenting were included (n = 1300). Among 19 studies, the success rate of TRA carotid stenting was .951 (95% confidence interval [CI]: .926-.975); death rate was .022 (.011-.032); stroke rate was .005 (.001-.008); radial artery occlusion rate was .008 (.003-.013); and forearm hematoma rate was .003 (-.000 to .006). Among 4 studies comparing TRA and TFA, the success rate was lower (odds ratio: .02; 95% CI: .00-.23) and crossover rate was higher (odds ratio: 40.16; 95% CI: 4.41-365.73) with TRA. Thus, transradial neuro-interventional surgery has a lower success rate than TFA.

Symptomatic carotid artery stenosis is a significant contributor to ischemic strokes. Carotid artery stenting (CAS) is usually indicated for secondary stroke prevention. This study evaluates the safety and efficacy of CAS performed within a short time frame from symptom onset.

We conducted a single-center, retrospective study of consecutive patients who underwent CAS for symptomatic carotid stenosis within eight days of symptom onset from July 2019 to January 2022. Data on demographics, medical history, procedural details, and follow-up outcomes were analyzed. The primary outcome measure was the recurrence of the stroke within the first month post-procedure. Secondary outcomes included mortality, the rate of intra-procedural complications, and hyperperfusion syndrome.

We included 93 patients with a mean age of 71.7 ± 11.7 years. The median time from symptom onset to CAS was 96 h. The rate of stroke recurrence was 5.4% in the first month, with a significant association between the number of stents used and increased recurrence risk. Mortality within the first month was 3.2%, with an overall mortality rate of 11.8% after a median follow-up of 19 months. Intra-procedural complications were present in five (5.4%) cases and were related to the number of stents used (p = 0.002) and post-procedural angioplasty (p = 0.045). Hyperperfusion syndrome occurred in 3.2% of cases.

Early CAS within the high-risk window post-symptom onset is a viable secondary stroke prevention strategy in patients with symptomatic carotid artery stenosis. The procedure rate of complication is acceptable, with a low recurrence of stroke. However, further careful selection of patients for this procedural strategy is crucial to optimize outcomes.

There is a growing interest in performing coronary artery and neurovascular interventions via the radial artery; however, few studies have examined the outcomes of transradial carotid stenting. Therefore, our study aimed to compare cerebrovascular outcomes and crossover rates in carotid stenting between transradial and traditional transfemoral approaches.

A systematic review was performed by searching three electronic databases from inception to June 2022 in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. In addition, random effect meta-analysis was used to pool the odds ratios (ORs) for stroke, transient ischemic attack, major adverse cardiac events, death, major vascular access site complications, and procedure crossover rates between the transradial and transfemoral approaches.

A total of 6 studies were included involving a total of n = 567 transradial and n = 6176 transfemoral procedures. The ORs for stroke, transient ischemic attack, and major adverse cardiac events were 1.43 (95% confidence interval, CI 0.72-2.86, I2 = 0), 0.51 (95% CI 0.17-1.54, I2 = 0), and 1.08 (95% CI 0.62-1.86, I2 = 0), respectively. Neither the major vascular access site complication rate (OR 1.11, 95% CI 0.32-3.87, I2 = 0) nor crossover rate (OR 3.94, 95% CI 0.62-25.11, I2 = 57%) showed statistically significant differences between the two approaches.

The modest quality of the data suggested comparable procedural outcomes between the transradial and transfemoral approaches when performing carotid stenting; however, high level evidence regarding postoperative brain images and risk of stroke in transradial carotid stenting are lacking. Therefore, it is reasonable for interventionists to weigh up the risks of neurological events and potential benefits, including fewer access site complications, before choosing the radial or femoral arteries as access sites. Future large-scale randomized controlled trials are imperative.

To describe through emblematic images rare but clinically relevant carotid artery stenting complications that occurred at two high-volume centres for carotid artery stenting (CAS).

CAS is an alternative to carotid endarterectomy (CEA) for the treatment of carotid artery stenosis in patients judged to be at high risk for CEA. CAS complications range between 1 and 9% and are higher in older patients complaining of neurological symptoms at the time of presentation. Besides periprocedural or early-after-procedure stroke, which remains the true Achilles' heel of CAS, other dramatic complications might compromise the clinical outcomes of this procedure.

Five infrequent complications, out of more than 1000 CAS performed in the years 2016-2021, have been described.

Among CAS complications, acute carotid stent thrombosis, rescue retrieval of a disconnected distal cerebral embolic protection device, plaque prolapse after carotid stenting, cerebral hyperperfusion syndrome (CHS), and radial artery long sheath entrapment requiring surgical intervention were found to account for 0.3% of the total number of procedures performed by operators with high CAS volume.

Unusual CAS complications may infrequently occur, even in hands of expert operators. To know how to deal with such complications might help interventionalists to improve CAS performance.

Neuroendovascular treatment via transradial access (TRA) has gained popularity as a minimally invasive technique. However, the flow reversal (FR) system, reported useful in carotid artery stenting (CAS), cannot be applied via TRA because it requires an access route of more than 8 F. Herein, we report the utility of a modified FR system applied via TRA using a sheathless 8-F balloon guide catheter and a 2.6-F balloon catheter.

In a retrospective analysis of a single-center consecutive case series, patients with CAS and vulnerable plaques who were treated with CAS via TRA using a modified FR system from June 2022 to August 2022 were examined. High-intensity spots were assessed on postprocedural diffusion-weighted magnetic resonance images. Puncture site complications at discharge and cardiovascular events for 1 year after CAS were also evaluated.

Ten patients were included in this study. There were no high-intensity spots on diffusion-weighted magnetic resonance images after CAS. No procedure-related complications, including radial artery occlusion or cardiovascular events, were observed.

This study suggests that CAS with FR using our modified system is feasible via TRA and may be an effective technique with a low rate of vascular complications.

Transradial artery access (TRA) for neurointerventional procedures is gaining widespread acceptance. However, complications that were previously rare may arise as TRA procedures increase. Here we report a series of retained catheter cases with a literature review.

All patients who underwent a neurointerventional procedure during a 23-month period at a single institution were retrospectively reviewed for a retained catheter in TRA cases. In cases of retained catheters, imaging was reviewed for anatomical variances in the radial artery, and clinical and demographic case details were analyzed.

A total of 1386 nondiagnostic neurointerventional procedures were performed during the study period, 631 (46%) initially via TRA. The 631 TRA cases were performed for aneurysm embolization (n=221, 35%), mechanical thrombectomy (n=116, 18%), carotid stent/angioplasty (n=40, 6%), arteriovenous malformation embolization (n=38, 6%), and other reasons (n=216, 34%). Thirty-nine (6%) TRA procedures crossed over to femoral access, most commonly because the artery of interest could not be catheterized (26/39, 67%). A retained catheter was identified in five cases (1%), and one (0.2%) patient had an entrapped catheter that was recovered. All six patients with a retained or entrapped catheter had aberrant radial anatomy.

Retained catheters for neurointerventional procedures performed via TRA are rare. However, this complication may be associated with variant radial anatomy. With the increased use of TRA for neurointerventional procedures, awareness of anatomical abnormalities that may lead to a retained catheter is necessary. We propose a simple protocol to avoid catheter entrapment, including in emergent situations such as TRA for stroke thrombectomy.

The transradial (TR) approach has emerged as an alternative to the transfemoral (TF) approach in carotid artery stenting (CAS) because of its perceived benefits in access site complications and overall patient experience.

To assess outcomes of TF vs TR approach for CAS.

This is a retrospective single-center review of patients receiving CAS through the TR or TF route between 2017 and 2022. All patients with symptomatic and asymptomatic carotid disease who underwent attempted CAS were included in our study.

A total of 342 patients were included in this study: 232 underwent CAS through TF approach vs 110 through the TR route. On univariate analysis, the rate of overall complications was more than double for the TF vs TR cohort; however, this did not achieve statistical significance (6.5% vs 2.7%, odds ratio [OR] = 0.59 P = .36). The rate of cross-over from TR to TF was significantly higher on univariate analysis (14.6 % vs 2.6%, OR = 4.77, P = .005) and on inverse probability treatment weighting analysis (OR = 6.11, P < .001). The rate of in-stent stenosis (TR: 3.6% vs TF: 2.2%, OR = 1.71, P = .43) and strokes at follow-up (TF: 2.2% vs TR: 1.8%, OR = 0.84, P = .84) was not significantly different. Finally, median length of stay was comparable between both cohorts.

The TR approach is safe, feasible, and provides similar rates of complications and high rates of successful stent deployment compared with the TF route. Neurointerventionalists adopting the radial first approach should carefully assess the preprocedural computed tomography angiography to identify patients amenable to TR approach for carotid stenting.

Despite an overall surge in transradial access (TRA) for neurointerventional procedures, the feasibility and safety of TRA carotid artery angioplasty and stenting using balloon guide catheters (BGCs) through a short 8-Fr sheath have not been studied. In this study, we present our experience of using Walrus BGC through TRA for carotid artery stent placement.

To define the safety and efficacy of using a balloon guide catheter for carotid stenting by a transradial approach.

Our prospectively maintained retrospective database was reviewed, and consecutive patients were identified who underwent elective carotid artery stenting through TRA using Walrus BGC between January 2021 and June 2022. Demographics, procedural details including access site complications, the rate of radial to groin conversion, and procedure-related transient ischemic attack or stroke were reviewed.

Twenty patients were identified who underwent carotid artery angioplasty and stenting through TRA Walrus BGC use; the mean age was 66 years (range 42-89), and 67% were male. A short 8-Fr sheath was used in all patients without any complications. Two of 20 patients required TRA conversion to transfemoral access, both secondary to severe spasm of the radial artery after initial access inhibiting further advancement of the Walrus BGC.

Use of Walrus BGC by TRA through an 8-Fr sheath for carotid artery stenting is safe and feasible with a low rate of conversion to transfemoral access and no access site complications.

There is an increasing number of transradial approach (TRA) for carotid artery stenting (CAS), however, similar techniques and materials as for femoral access are used. We report the results of TRA lower profile technique for CAS using a 7 F Simmons guiding catheter, especially in terms of feasibility and procedural safety in a single center.

We retrospectively analyzed 68 consecutive patients with symptomatic extracranial carotid stenoses who underwent 75 CAS between January 2018 and December 2021. The success and crossover rate, procedural time, fluoroscopy, clinical outcomes, technical considerations, and procedural complications were analyzed.

TRA CAS with Simmons guiding catheter was successful in 67/75 (89.3%) cases, with a 7 (9.3%) crossover rate. Fluoroscopy mean time was 15.8 minutes. Two forearm hematomas were described. No ischemic or surgical site complications were reported.

In our experience frontline TRA with a 7 F Simmons guiding catheter is feasible with high procedural success and a low rate of access site complications.

Carotid artery angioplasty and stenting (CAS) is an established procedure to treat carotid artery stenosis for either primary or secondary prevention of stroke. Randomized clinical trials have shown an increased risk of periprocedural cerebrovascular events with CAS compared with carotid endarterectomy (CEA). Several strategies have been proposed to mitigate this risk, including alternative vascular access site, proximal/distal embolic protection devices, and dual-layer stents, among others.

This review provides a general overview of current embolic protection strategies for CAS. The phases of the procedure which can affect the early risk of stroke and how to reduce it with novel techniques and devices have been discussed.

Innovations in device technologies have dramatically improved the safety and efficacy of CAS. To minimize the gap with surgery, a thorough, patient-oriented approach should be pursued. Endovascular technologies and techniques should be selected on an individual basis to address unique lesion characteristics and vascular anatomies. Meticulous pre-procedural planning, both clinical and anatomical, is needed to assess the embolic risk of each procedure. Only by having an in-depth understanding of the wide range of available endovascular devices and techniques, the operator will choose the most appropriate strategy to optimize CAS results.

The aim of this study was to evaluate the feasibility, safety and efficacy of transradial/brachial (TR/TB) carotid artery stenting (CAS) with proximal cerebral protection (PCP) as a first line of treatment of carotid artery stenosis.

Among 556 patients with significant (>50% if symptomatic or >70% if asymptomatic by Doppler US) unilateral, lipid-rich carotid artery stenosis undergoing TR/TB CAS, 137 (24.5%) deemed at high-risk for periprocedural cerebral embolization were scheduled for PCP with Mo.MA Ultra or Mo.MA mono-balloon. In patients with very complex anatomy the standard technique was modified loading the Mo.MA catheter without mandrel on two-wire system (so called 'No MAndrel 2 wire' technique, No.MA2) to increase support and deliverability. Device, technical and procedural successes both acute and at follow-up were the main outcomes.

Mean patients' age was 74±7 years (93% male), 15% were symptomatic and 59.6% owned 'high-surgical-risk' features. Stenosis degree was 85±7% with soft composition in all (by CT-angiography). TR and TB approach were selected in 92 (67%) and 45 (33%) patients, respectively. Target carotid axes were right, left bovine and left non bovine in 55%, 38% and 7% of patients. Procedures were successfully completed in all patients (intention-to-treat basis) with the standard Mo.MA Ultra system in 129 patients and the Mo.MA mono-balloon in 8 patients. No.MA2 technique was succesfully used in 16 patients as 'bailout' and in 27 patients as 'first line'). Device and technical success was 97% (133/137 patients) due to crossover to femoral access in 3 cases, and Mo.MA too short to engage the ECA in 1 patient. The procedural success was 96.7% (131/137, two minor strokes). Procedural time and fluoroscopy time were increased with No.MA2 technique. One major vascular complication occurred, in the TB group, while chronic radial occlusion was detected by Doppler ultrasound in 7/92 patients (7.1%) at 372±163 days of follow-up. The event-free survival was 91% and the stroke rate was 0%.

TR/TB CAS with proximal protection is a feasible, safe and effective strategy and may be considered a first line strategy in all comer patients.

Carotid artery stenting (CAS) is frequently used for patients at high risk for carotid endarterectomy. However, there are limited data comparing transradial or transbrachial (tr/tbCAS) access with more established CAS approaches. Therefore, we examined the effect of a tr/tbCAS approach versus a transfemoral (tfCAS) or transcarotid (TCAR) approach on outcomes after CAS.

We identified all patients undergoing CAS in the Vascular Quality Initiative registry from January 2016 to December 2021. We compared outcomes across 1:3 propensity score-matched cohorts of patients who underwent tr/tbCAS versus tfCAS or tr/tbCAS versus TCAR. As a secondary analysis, we assessed outcomes stratified by carotid symptom status. Our primary outcome was a composite end point of in-hospital stroke/death.

Among 40,835 CAS patients, 962 (2.4%) underwent tr/tbCAS, 18,840 (46%) underwent tfCAS, and 21,033 (52%) underwent TCAR. Among matched patients who underwent tr/tbCAS versus tfCAS, there was no significant difference in the risk of stroke/death (4.1% vs 2.9%; relative risk [RR] 1.4; 95% confidence interval [CI], 0.95-2.1), but tr/tbCAS was associated with a higher risk of death (2.4% vs 1.3%; RR, 1.8; 95% CI, 1.1-3.1). In the symptomatic subgroup, tr/tbCAS was associated with a higher risk of stroke/death (6.1% vs 3.9%; RR, 1.6; 95% CI, 1.0-2.4) and death (3.6% vs 1.7%; RR, 2.1; 95% CI, 1.2-3.7), but there were no differences in asymptomatic patients. After adjustment for mRS in patients with preoperative stroke, there were no significant differences in stroke/death (RR, 1.1; 95% CI, 0.66-1.9) or death (RR, 1.6; 95% CI, 0.81-3.3) between groups. In matched patients who underwent tr/tbCAS versus TCAR, tr/tbCAS was associated with a higher risk of stroke/death (4.2% vs 2.3%; RR, 1.8; 95% CI, 1.2-2.7) and death (2.4% vs 0.5%; RR, 4.8; 95% CI, 2.4-9.5). In the symptomatic subgroup, tr/tbCAS remained associated with a higher risk of stroke/death (6.2% vs 2.4%; RR, 2.6; 95% CI, 1.6-4.2) and death (3.7% vs 0.7%; RR, 5.6; 95% CI, 2.6-12), but there were no differences in asymptomatic patients. After adjustment for Modified Rankin Scale in patients with preoperative stroke, there were no significant differences in stroke/death (RR, 1.4; 95% CI, 0.79-2.6) or death (RR, 2.3; 95% CI, 0.95-5.7) between groups.

Compared with tfCAS or TCAR, tr/tbCAS was associated with a higher risk of in-hospital stroke/death in symptomatic patients, which was driven primarily by a higher risk of death. These inferior outcomes were partly attributable to more severe preoperative neurologic disability in tr/tbCAS patients. In contrast, there were no differences in outcomes in asymptomatic patients. Overall, our findings highlight the importance of guideline-directed patient selection in tr/tbCAS.

Use of the transradial access (TRA) approach for neuroendovascular procedures has been increasing in recent years. Our aim is to assess the feasibility, success rate, and complications associated with TRA for intracranial aneurysm embolization.

PubMed, Scopus, and Embase were systematically searched for studies using TRA for intracranial aneurysm embolization. Random-effects models were used to obtain pooled rates of procedural success and complications.

Twenty-four studies comprising 1283 (85.9%) TRA and 122 (8.2%) distal TRA aneurysm embolization procedures were included. The pooled success rate of the 18 studies in the meta-analysis was 93.5% (95% confidence interval [CI], 91.1%-95.8%). The pooled thromboembolic complication rate was 0.5% (95% CI, 0.1%-0.9%), the hemorrhagic complication rate was 0.5% (95% CI, 0.1%-0.9%), and the access site complication rate was 0.8% (95% CI, 0.3%-1.3%). One study (4.3%) used exclusively a 7-French guide catheter, and most used a 6-French guide catheter (22 of 23 studies, 95.7%), which was further incorporated as part of a triaxial configuration through a sheathless 8-French system in 4 studies (17.4%), 7-French guide catheter in 2 studies (8.7%), and 8-French sheath in 1 study (4.3%). The embolization techniques used were flow diverter placement in 451 cases (39.1%), coiling in 376 (32.6%), stent-assisted coiling in 127 (11.0%), balloon-assisted coiling in 104 (9.0%), Woven EndoBridge system in 50 (4.3%), and flow diverter placement plus coiling in 42 (3.6%).

Treating intracranial aneurysms using various embolization techniques through TRA is feasible and associated with low access site and intraoperative complications.

The adoption of the transradial approach (TRA) has been increasing in popularity as a primary method to conduct both diagnostic and therapeutic interventions. As this technique gains broader acceptance and use within the neuroendovascular community, comparing its complication profile with a better-established alternative technique, the transfemoral approach (TFA), becomes more important. This study aimed to evaluate the safety of TRA compared with TFA in patients undergoing diagnostic, therapeutic, and combined neuroendovascular procedures.

A systematic review and meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A literature search of PubMed and other databases was conducted for studies from all available dates. To compare TRA and TFA, we performed an indirect meta-analysis between studies that mentioned the complications of the procedures.

Our search yielded 532 studies, of which 108 met full inclusion criteria. A total of 54,083 patients (9137 undergoing TRA and 44,946 undergoing TFA) were included. Access site complication rate was lower in TRA (1.62%) compared with TFA (3.31%) (P < 0.01). Neurological complication rate was lower in TRA (1.64%) compared with TFA (3.82%) (P = 0.02 and P < 0.01, respectively). Vascular spasm rate was higher in TRA (3.65%) compared with TFA (0.88%) (P < 0.01). Wound infection complication rate was higher in TRA (0.32%) compared with TFA (0.2%) (P < 0.01).

Patients undergoing TFA are significantly more likely to experience access site complications and neurological complications compared with patients undergoing TRA. Patients undergoing TRA are more likely to experience complications such as wound infections and vascular spasm.

Transradial access (TRA) for neuroendovascular procedures is increasing in prevalence. The safety benefits of TRA at a patient level may be offset at a population level by a paradoxical increase in transfemoral access (TFA) vascular access site complications (VASCs), the so-called "radial paradox."

To study the effect of TRA adoption on TFA performance and outcomes in neuroendovascular procedures.

Data were collected for all procedures performed over a 10-mo period after radial adoption at a single center.

Over the study period, 1084 procedures were performed, including 719 (66.3%) with an intent to treat by TRA and 365 (33.7%) with an intent to treat by TFA. Thirty-two cases (4.4%) crossed over from TRA to TFA, and 2 cases (0.5%) crossed over from TFA to TRA. TFA was performed in older patients (mean [standard deviation] TFA, 63 [15] vs TRA, 56 [16] years) using larger sheath sizes (≥7 French; TFA, 56.2% vs TRA, 2.3%) ( P < .001 for both comparisons). Overall, 29 VASCs occurred (2.7%), including 27 minor (TFA, 4.6% [18/395] vs TRA, 1.3% [9/689], P = .002) and 2 major (TFA, 0.3% [1/395] vs TRA, 0.1% [1/689], P > .99) complications. Independent predictors of VASC included TFA (OR 2.8, 95% confidence interval [CI] 1.1-7.4) and use of dual antiplatelet therapy (OR 4.2, 95% CI 1.6-11.1).

TFA remains an important access route, despite a predominantly radial paradigm, and is disproportionately used in patients at increased risk for VASCs. TFA proficiency may still be achieved in predominantly radial practices without an increase in femoral complications.

Arterial vascular access is a frequently performed procedure, with a high possibility for adverse events (e.g. pneumothorax, haemothorax, haematoma, amputation, death), and additional techniques such as ultrasound may be useful for improving outcomes. However, ultrasound guidance for arterial access in adults is still under debate.

To assess the effects of ultrasound guidance for arterial (other than femoral) catheterisation in adults.

We searched CENTRAL, MEDLINE, Embase, LILACS, and CINAHL on 21 May 2021. We also searched IBECS, WHO ICTRP, and ClinicalTrials.gov on 16 June 2021, and we checked the reference lists of retrieved articles.

Randomised controlled trials (RCTs), including cross-over trials and cluster-RCTs, comparing ultrasound guidance, alone or associated with other forms of guidance, versus other interventions or palpation and landmarks for arterial (other than femoral) guidance in adults.

Two review authors independently performed study selection, extracted data, assessed risk of bias, and assessed the certainty of evidence using GRADE.

We included 48 studies (7997 participants) that tested palpation and landmarks, Doppler auditory ultrasound assistance (DUA), direct ultrasound guidance with B-mode, or any other modified ultrasound technique for arterial (axillary, dorsalis pedis, and radial) catheterisation in adults. Radial artery Real-time B-mode ultrasound versus palpation and landmarks Real-time B-mode ultrasound guidance may improve first attempt success rate (risk ratio (RR) 1.44, 95% confidence interval (CI) 1.29 to 1.61; 4708 participants, 27 studies; low-certainty evidence) and overall success rate (RR 1.11, 95% CI 1.06 to 1.16; 4955 participants, 28 studies; low-certainty evidence), and may decrease time needed for a successful procedure (mean difference (MD) -0.33 minutes, 95% CI -0.54 to -0.13; 4902 participants, 26 studies; low-certainty evidence) up to one hour compared to palpation and landmarks. Real-time B-mode ultrasound guidance probably decreases major haematomas (RR 0.35, 95% CI 0.23 to 0.56; 2504 participants, 16 studies; moderate-certainty evidence). It is uncertain whether real-time B-mode ultrasound guidance has any effect on pseudoaneurysm, pain, and quality of life (QoL) compared to palpation and landmarks (very low-certainty evidence). Real-time B-mode ultrasound versus DUA One study (493 participants) showed that real-time B-mode ultrasound guidance probably improves first attempt success rate (RR 1.35, 95% CI 1.11 to 1.64; moderate-certainty evidence) and time needed for a successful procedure (MD -1.57 minutes, 95% CI -1.78 to -1.36; moderate-certainty evidence) up to 72 hours compared to DUA. Real-time B-mode ultrasound guidance may improve overall success rate (RR 1.13, 95% CI 0.99 to 1.29; low-certainty evidence) up to 72 hours compared to DUA. Pseudoaneurysm, major haematomas, pain, and QoL were not reported. Real-time B-mode ultrasound versus modified real-time B-mode ultrasound Real-time B-mode ultrasound guidance may decrease first attempt success rate (RR 0.68, 95% CI 0.55 to 0.84; 153 participants, 2 studies; low-certainty evidence), may decrease overall success rate (RR 0.93, 95% CI 0.86 to 1.01; 153 participants, 2 studies; low-certainty evidence), and may lead to no difference in time needed for a successful procedure (MD 0.04 minutes, 95% CI -0.01 to 0.09; 153 participants, 2 studies; low-certainty evidence) up to one hour compared to modified real-time B-mode ultrasound guidance. It is uncertain whether real-time B-mode ultrasound guidance has any effect on major haematomas compared to modified real-time B-mode ultrasound (very low-certainty evidence). Pseudoaneurysm, pain, and QoL were not reported. In-plane versus out-of-plane B-mode ultrasound In-plane real-time B-mode ultrasound guidance may lead to no difference in overall success rate (RR 1.00, 95% CI 0.96 to 1.05; 1051 participants, 8 studies; low-certainty evidence) and in time needed for a successful procedure (MD -0.06 minutes, 95% CI -0.16 to 0.05; 1134 participants, 9 studies; low-certainty evidence) compared to out-of-plane B-mode ultrasound up to one hour. It is uncertain whether in-plane real-time B-mode ultrasound guidance has any effect on first attempt success rate or major haematomas compared to out-of-plane B-mode ultrasound (very low-certainty evidence). Pseudoaneurysm, pain, and QoL were not reported. DUA versus palpation and landmarks DUA may lead to no difference in first attempt success rate (RR 1.01, 95% CI 0.90 to 1.14; 666 participants, 2 studies; low-certainty evidence) or overall success rate (RR 0.99, 95% CI 0.92 to 1.07; 666 participants, 2 studies; low-certainty evidence) and probably increases time needed for a successful procedure (MD 0.45 minutes, 95% CI 0.20 to 0.70; 500 participants, 1 study; moderate-certainty evidence) up to 72 hours compared to palpation and landmarks. Pseudoaneurysm, major haematomas, pain, and QoL were not reported. Oblique-axis versus long-axis in-plane B-mode ultrasound Oblique-axis in-plane B-mode ultrasound guidance may increase overall success rate (RR 1.27, 95% CI 1.05 to 1.53; 215 participants, 2 studies; low-certainty evidence) up to 72 hours compared to long-axis in-plane B-mode ultrasound. It is uncertain whether oblique-axis in-plane B-mode ultrasound guidance has any effect on first attempt success rate, time needed for a successful procedure, and major haematomas compared to long-axis in-plane B-mode ultrasound. Pseudoaneurysm, pain, and QoL were not reported. We are uncertain about effects in the following comparisons due to very low-certainty evidence and unreported outcomes: real-time B-mode ultrasound versus palpation and landmarks (axillary and dorsalis pedis arteries), real-time B-mode ultrasound versus near-infrared laser (radial artery), and dynamic versus static out-of-plane B-mode ultrasound (radial artery).

Real-time B-mode ultrasound guidance may improve first attempt success rate, overall success rate, and time needed for a successful procedure for radial artery catheterisation compared to palpation, or DUA. In addition, real-time B-mode ultrasound guidance probably decreases major haematomas compared to palpation. However, we are uncertain about the evidence on major haematomas and pain for other comparisons due to very low-certainty evidence and unreported outcomes. We are also uncertain about the effects on pseudoaneurysm and QoL for axillary and dorsalis pedis arteries catheterisation. Given that first attempt success rate and pseudoaneurysm are the most relevant outcomes for people who underwent arterial catheterisation, future studies must measure both. Future trials must be large enough to detect effects, use validated scales, and report longer-term follow-up.

Although enthusiasm for transradial access for neurointerventional procedures has grown, a unique set of considerations bear emphasis to preserve safety and minimize complications. In the first part of this review series, we reviewed anatomical considerations for safe and easy neuroendovascular procedures from a transradial approach. In this second part of the review series, we aim to (1) summarize evidence for safety of the transradial approach, and (2) explain complications and their management.

Transradial artery (TRA) catheterization for neuroendovascular procedures is associated with a lower risk of complications than transfemoral artery (TFA) procedures. However, the majority of literature on TRA access pertains to diagnostic procedures rather than interventional treatments.

To compare TRA and TFA approaches for cerebrovascular interventions.

All patients with an endovascular intervention performed at a single center from October 1, 2018 to December 31, 2019 were retrospectively analyzed. Patients were grouped into 2 cohorts on the basis of whether TRA or TFA access was used. Outcomes included complications, fluoroscopy times, and total contrast administered.

A total 579 interventional treatments were performed during the 15-mo study period. TFA procedures (n = 417) were associated with a significantly higher complication rate than TRA (n = 162) procedures (43 cases [10%] vs 5 cases [3%]; P = .008). After excluding patients who underwent thrombectomy and performing a propensity adjustment (including age, sex, pathology, procedure, sheath size, and catheter size), TRA catheterization was associated with decreased odds of a complication (odds ratio, 0.25; 95% CI 0.085-0.72; P = .01), but no significant difference in the amount of contrast administered (6.7-mL increase; 95% CI, -7.2 to 20.6; P = .34) or duration of fluoroscopy (2.1-min increase; 95% CI, -2.5 to 6.7; P = .37) compared with TFA catheterization.

Neurointerventional procedures and treatments for a variety of pathologies can be performed successfully using the TRA approach, which is associated with a lower risk of complications and no difference in fluoroscopy duration compared with the TFA approach.

Atherosclerotic disease of the carotid artery places patients at risk of ischemic stroke and consequently is a target of medical, endovascular and open surgical management. Various imaging modalities are used to characterize anatomy/severity of carotid disease and justify intervention, each having advantages and disadvantages. Carotid revascularization techniques including carotid artery stenting, carotid endarterectomy, and transcarotid artery revascularization vary in invasiveness and are not equally suitable for certain subsets of patients. As such, providing quality care for patients with carotid disease requires a multidisciplinary team of experts in clinical diagnosis, image interpretation, medical management, endovascular intervention, and surgical treatment.

Carotid artery stenting (CAS) is a procedure for stroke prevention, usually done from femoral artery access. Reports of CAS using radial artery access have adopted techniques similar to those used for transfemoral CAS. Initial experience with a simpler and lower profile technique for transradial carotid stenting is described here.

Of 55 consecutive elective CAS cases with standard (not bovine) arch anatomy performed during a 15 month time period by the same operator, 20 were selected for transradial treatment using a 6 F Simmons 2 guide catheter. This was a retrospective analysis of those initial 20 patients compared with the 35 patients treated with elective transfemoral CAS. The CAS database was reviewed for clinical indications, technique, procedure and fluoroscopy times, and clinical outcomes.

All procedures were technically successful (no crossovers). No patient had a decline in National Institutes of Health Stroke Scale score or modified Rankin Scale score within 30 days. Mean (95% CI) procedural times for transradial CAS were slightly higher than transfemoral CAS (29.4 (26.0 to 32.7) vs 23.8 (21.2 to 26.4) min, p=0.0098). Mean (95% CI) fluoroscopy times were also higher for transradial CAS compared with transfemoral CAS (9.6 (8.0 to 11.2) vs 6.4 (5.4 to 7.4), p=0.0006). One patient developed a radial artery pseudoaneurysm which required elective surgical repair.

Transradial carotid stenting using the described lower profile technique provides another effective option in the array of surgical procedures for the treatment of carotid artery stenosis. Relative procedural and fluoroscopy times may initially be longer compared with transfemoral carotid stenting for experienced CAS operators, although absolute differences are small.

Currently, there are no large-scale studies in the neurointerventional literature comparing safety between transradial (TRA) and transfemoral (TFA) approaches for flow diversion procedures. This study aims to assess complication rates in a large multicenter registry for TRA versus TFA flow diversion.

We retrospectively analyzed flow diversion cases for cerebral aneurysms from 14 institutions from 2010 to 2019. Pooled analysis of proportions was calculated using weighted analysis with 95% CI to account for results from multiple centers. Access site complication rate and overall complication rate were compared between the two approaches.

A total of 2,285 patients who underwent flow diversion were analyzed, with 134 (5.86%) treated with TRA and 2151 (94.14%) via TFA. The two groups shared similar patient and aneurysm characteristics. Crossover from TRA to TFA was documented in 12 (8.63%) patients. There were no access site complications in the TRA group. There was a significantly higher access site complication rate in the TFA cohort as compared with TRA (2.48%, 95% CI 2.40% to 2.57%, vs 0%; p=0.039). One death resulted from a femoral access site complication. The overall complications rate was also higher in the TFA group (9.02%, 95% CI 8.15% to 9.89%) compared with the TRA group (3.73%, 95% CI 3.13% to 4.28%; p=0.035).

TRA may be a safer approach for flow diversion to treat cerebral aneurysms at a wide range of locations. Both access site complication rate and overall complication rate were lower for TRA flow diversion compared with TFA in this large series.

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.

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.

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.

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.

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.

Carotid stenosis is responsible for approximately 15% of ischemic strokes. Carotid revascularization significantly decreases patients' stroke risk. Carotid endarterectomy has first-line therapy for moderate-to-severe carotid stenosis after a series of pivotal randomized controlled trials were published almost 30 years ago. Revascularization with carotid stenting has become a popular and effective alternative in a select subpopulation of patients. We review the current state of the literature regarding revascularization indications, patient selection, advantages of each revascularization approach, timing of intervention, and emerging interventional techniques, such as transcarotid artery revascularization.

The transradial artery (TRA) approach for neuroendovascular procedures continues to gain popularity, but neurointerventionalists still lag behind interventional cardiologists in the adoption of a TRA-first approach. This study compares the complications and efficiency of the TRA approach to the standard transfemoral artery (TFA) approach at our institution during our initial phase of adopting a TRA-first approach.

A retrospective analysis was performed on all consecutive neuroangiographic procedures performed at a large cerebrovascular center from October 1, 2018 to June 30, 2019. The standard TFA approach was compared with TRA access, with the primary outcome of complications analyzed via a propensity-adjusted analysis.

A total of 1050 consecutive procedures were performed on 877 patients during this 9-month period; 206 (20%) procedures were performed via TRA and 844 (80%) via TFA. The overall complication rate was significantly higher with the TFA procedures than with the TRA procedures (7% (60/844) vs 2% (4/206), respectively; p=0.003). A propensity-adjusted analysis showed that the TFA approach was a significant risk factor for a complication (OR 3.6, 95% CI 1.3 to 10.2, p=0.01). However, the propensity analysis showed that fluoroscopy times were on average 4 min less for TFA procedures than for TRA procedures (p=0.003).

The TRA approach for neuroendovascular procedures appears to be safer than the TFA approach. Although a steep learning curve is initially encountered when adopting the TRA approach, the transition to a TRA-first practice can be performed safely for neurointerventional procedures and may reduce complications.