Forearm-only transarterial and transvenous approach for endovascular intervention of dural arteriovenous fistula

BackgroundTransradial arterial access has become widely used as a less invasive approach in neuroendovascular therapy, but the forearm venous approach has rarely been reported.ObjectivesThis study aimed to assess the safety and efficacy of forearm transvenous neurointervention for intracranial lesions. We present our experience with a simultaneous forearm-only transarterial and venous approach (fTAVA) for dural arteriovenous fistulas (dAVFs).MethodsWe retrospectively reviewed a prospective database of consecutive patients who underwent fTAVA for dAVFs between 2021 and 2024. fTAVA was performed using the right radial artery and superficial forearm vein as puncture sites. Arterial closure was achieved using a radial compression device, whereas bandage compression was used for venous closure. Procedural success, angiographic results, procedure-related complications and patient satisfaction were evaluated.ResultsOverall, 13 (8 carotid-cavernous sinus and 5 transverse-sigmoid sinus fistulas) procedures using fTAVA were successfully performed with favorable outcomes. Arterial puncture was performed at the distal radial artery in nine cases. The venous puncture site was the median cubital vein in nine cases and the forearm cephalic vein in four cases. The targeted fistulas were distal to the right jugular vein in four cases and the left jugular vein in nine cases. They were successfully accessed in all cases. The angiographic result was total occlusion in eleven cases and subtotal occlusion in two cases. There was one patient with minor access-site complication in distal radial artery.ConclusionsThe fTAVA is a safe and effective method for the endovascular treatment of dAVFs and is associated with reduced patient discomfort.

Preliminary Experience With Novel Straight 3-Fr Guiding Sheath for Transradial Access in Endovascular Treatment: Feasibility and Safety

BACKGROUND AND OBJECTIVES

Radial artery diameter may limit whether a guiding sheath (GS) can be used via transradial artery access (TRA). A smaller GS may reduce the risk of access site-related complications. This study investigated the feasibility and safety of endovascular treatment (EVT) using a straight-shaped 3-Fr GS (Axcelguide; Medikit).

METHODS

Patients who underwent EVT with a straight-shaped 3-Fr GS at 3 institutions between April 2022 and March 2024 were retrospectively reviewed. Patient background, anatomic and procedural factors, and complications were recorded.

RESULTS

Twenty-six pathologies were treated with EVT using a 3-Fr GS. Median radial artery diameter was 1.9 mm, and distal TRA (73.1%) was selected more often than TRA (26.9%) as the access site. The breakdown of target pathologies and the role of the 3-Fr GS were as follows: 12 unruptured cerebral aneurysms for intra-aneurysmal coiling, with 5 dural arteriovenous fistulas, 5 brain or head and neck tumors, 2 chronic subdural hematoma, 1 arteriovenous malformation, and 1 hereditary hemorrhagic telangiectasia for transarterial embolization. A success rate of 96.2% was achieved, with no access site- or non-access site-related complications observed within 30 days.

CONCLUSION

The straight-shaped 3-Fr GS may be applicable for selected pathologies, allowing access even with RAs <2 mm in diameter and facilitating EVT without complications. Preliminary experience with the 3-Fr GS via TRA demonstrated excellent feasibility and safety.

Transradial Approach for Neurovascular Interventions : A Literature Review

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.

Transradial versus transfemoral access for mechanical thrombectomy: A single institution experience

BACKGROUND

There has been debate in the literature regarding the adoption of a "radial-first" approach for mechanical thrombectomy (MT) in acute ischemic stroke (AIS). Conflicting reports suggest that transradial access (TRA) may allow for shorter times to reperfusion while others conclude that long-term functional outcomes may favor transfemoral access (TFA). Here, we report a single-institution experience with the adoption of TRA as the primary route for acute stroke intervention.

METHODS

We retrospectively reviewed a single-institution database of patients undergoing MT for AIS from March 2020 to April 2023. This time period was selected to capture the change in clinical practice at our institution from TFA to TRA. Primary and secondary outcomes included technical success, procedural complications, and long-term functional outcomes. Patients were stratified into two cohorts from initial access. Cohorts were compared utilizing inferential statistics.

RESULTS

A total of 192 consecutive cases were identified, with 80 in the TFA cohort and 112 in the TRA cohort. There was no difference in outcomes with respect to time from puncture to recanalization, rates of successful recanalization (TICI ≥ 2b), number of passes, rates of symptomatic intracranial hemorrhage (sICH), modified Rankin scale (mRS) at discharge and 90 days, and 90-day mortality (p ≥ 0.05, all). The TRA had a higher rate of access conversion (p < 0.001), while the TFA cohort had a higher rate of access site complications (p < 0.05).

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

OBJECTIVE

Although mechanical thrombectomy (MT) is primarily performed via transfemoral access (TFA), transradial access (TRA) is a potential alternative in older patients or those with tortuous vessels. However, the small radial artery diameter restricts the use of large-bore balloon guides and aspiration catheters, a limitation that may be overcome using the sheathless technique. Thus, we aimed to explore the feasibility, efficacy, and safety of sheathless TRA-MT as a first-line treatment approach for acute ischemic stroke.

METHODS

This single-center retrospective case series included patients who underwent TRA-MT as first-line treatment between September 2020 and June 2023. Per our MT protocol, TRA was not the first-line approach in cases of left anterior circulation lesions with a type 3 aortic arch. We evaluated treatment effectiveness based on the successful recanalization rate, puncture-to-recanalization time, and modified first-pass effect; access route effectiveness based on the puncture-to-first-pass time and switch-to-TFA rate; and procedure safety based on procedure-related and severe puncture site complications.

RESULTS

Sheathless 8-F guide catheters were used in 68 % and large-bore aspiration catheters in 70 % of the procedures. Successful recanalization was achieved in 98 % of the patients, with a modified first-pass effect in 54 % of them. The median puncture-to-first-pass and puncture-to-recanalization times were 20.5 and 33 min, respectively. The rate of procedure-related complications was low (4 %), with no severe puncture site complications.

CONCLUSION

Sheathless TRA-MT enabled the use of large-bore guide and aspiration catheters, providing a swift approach to the target and satisfactory outcomes, and might be an effective first-line treatment for acute ischemic stroke.

Rate of periprocedural stroke in diagnostic cerebral angiograms comparing transradial versus transfemoral access

PURPOSE

Transradial access for neurointerventional procedures has increased in popularity over the past few years due to data from extrapolated interventional cardiology studies, patient preference, and early reports of feasibility using this approach. Our aim was to evaluate the incidence of periprocedural stroke in patients undergoing transradial versus transfemoral access for diagnostic cerebral angiograms.

METHODS

We retrospectively reviewed our neurointerventional database and identified all patients who underwent a diagnostic angiogram between May 2019 and July 2021. Patients were further divided into transradial versus transfemoral access. In patients with postprocedural stroke, symptoms and National Institute of Health Stroke Scale score were recorded. Pertinent laboratory values and procedural data was reviewed, including COVID status, platelet count, International normalized ratio (INR), Glomerular filtration rate (GFR), vessels catheterized, amount of contrast used, and fluoroscopy time. Imaging work-up for stroke symptoms was reviewed, if available.

RESULTS

Thousand two-hundred thirty eight diagnostic cerebral angiograms with 656 patients (53%) undergoing transradial access. Stroke symptoms after angiogram were only observed in the transradial group (5 patients; 0.4% total and 0.8% among radial access cases, respectively). Symptoms included word finding difficulty, paresthesia, or weakness. Three patients underwent cross-sectional imaging, computed tomography was negative in all three patients. Magnetic resonance imaging showed small, scattered infarcts in two patients. All symptoms resolved without additional hospitalization.

CONCLUSION

In our experience, using transradial access for diagnostic cerebral angiograms was associated with a low but not negligible incidence of periprocedural strokes. Patient anatomy should be evaluated prior to selection of vascular access. Patients should be made aware of a slightly higher periprocedural stroke risk with transradial access.

Transradial access for cerebral angiography and neurointerventional procedures: A meta-analysis and systematic review

PURPOSE

Transradial access (TRA) for diagnostic and interventional neurointerventional procedures has recently gained traction over transfemoral access (TFA) in the neurointerventional community. This meta-analysis aims to assess and summarize the utility of TRA in cerebral angiography and neurointerventional procedures.

METHODS

A systematic literature review was performed utilizing Pubmed, Embase, and Scopus databases. Using PRISMA guidelines, records were extracted with the following search terms: transradial approach, transradial access, radial access, cerebral angiogram, cerebral angiography, neurointervention, and neuroendovascular. The primary outcomes assessed were case success rate, complication rate, and crossover rate from TRA to TFA. Secondary analysis was performed on procedure time, fluoroscopy time, fluoroscopy time per vessel (diagnostic procedures only), contrast dose, radial artery diameter, distal radial artery diameter, and patient preference for TRA over TFA.

RESULTS

Sixty-two full-text articles were analyzed for this meta-analysis, representing 12,927 diagnostic and interventional TRA access patients. Our analysis revealed a combined diagnostic and interventional case success rate of 95.9% and complication rate of 3.5%, with crossover to TFA occurring in 4.9% of cases.

CONCLUSION

This meta-analysis demonstrates that TRA access for diagnostic angiography and neurointerventional procedures is a safe and effective approach, though determining a true complication rate is challenging as the definition of TRA complications has changed in various publications over time.

Vertebral Artery Access Considerations in Coil Embolization of Small Superior Cerebellar Artery Aneurysm

BACKGROUND

Coiling of small superior cerebellar artery aneurysms (sSCAAs) is challenging. We aimed to describe anatomic considerations in the vertebral and basilar artery (VA and BA) morphology for decision making in the coiling of sSCAAs.

METHODS

Eleven patients with sSCAAs (<5 mm) treated at our institution between April 2015 and February 2022 were included to show our concept of deciding access routes in the coiling of sSCAAs. The access route was decided on the basis of VA characteristics, BA curvature, and aneurysm laterality. Adequate aneurysm occlusion on angiography (Raymond-Roy grading scale I and II), good outcome (modified Rankin Score 0-2) at the last follow-up, and adverse outcomes were evaluated.

RESULTS

Simple coiling (n = 2), a balloon-assisted technique (n = 3), and stent-assisted technique (n = 6) were selected. At the last follow-up (median 13.0 months), adequate aneurysm occlusion and good outcome were obtained in all 9 patients (n = 10). Adverse outcomes were not observed. When VA dominance was equal, in the straight BA, the microcatheter insertion into the ipsilateral VA to the aneurysm was favorable to form a "fulcrum" on the contralateral side and obtain microcatheter stability. When an aneurysm was on the concave aspect of the curved BA, microcatheter insertion into the ipsilateral VA was favorable. As for the convex aspect's aneurysm location, the microcatheter insertion into the contralateral VA can be favored. Further, we described the VA origin classification as it relates to ease of access from a transradial approach.

CONCLUSIONS

Vertebrobasilar morphology may be important in deciding access routes in the coiling of sSCAAs.

A new very-small-bore Simmons guiding sheath for transradial neurointervention: Technical note and initial experience

Transradial access during neurointerventions has increased in popularity because of reduced complications and patient preference. Nevertheless, transradial cannulation into the left common carotid artery can be difficult technically because of the lack of catheter support in the aortic arch. Furthermore, the use of large sheaths can increase the risk of complications at the access site. Here, we developed a new very-small-bore transradial system using a 3F Simmons guiding sheath, to increase the procedural success rate and minimize access-site complications. This system can represent a valuable treatment option for neurointerventions and has the potential to expand the indications for transradial access.

Feasibility and Challenges of Transradial Approach in Neuroendovascular Therapy: A Retrospective Observational Study

Objective

Transradial approach (TRA) is increasingly used as a viable alternative to the traditional transfemoral approach (TFA) in neuroendovascular therapy (NET) owing to its potential anatomical benefits and lower puncture-site complication rates. However, the real-world challenges of implementing TRA-NET have not been thoroughly studied, particularly those related to guide catheter (GC) placement. In this study, we aimed to explore the feasibility and challenges of TRA-NET, with a specific focus on GC placement.

Methods

This retrospective observational study included patients who underwent NET at our institution between December 2019 and May 2022. Procedural success was defined as the successful placement of a GC in the target vessel. Cases in which a Simmons-shaped GC was used or the approach was changed to TFA were classified as difficult. Safety was assessed based on the rate of severe puncture-site complications requiring either blood transfusion or surgical intervention.

Results

Among the 310 patients who underwent NET during the study period, 222 (71.6%) with a median age of 74 years were selected for TRA-NET. The target vessel was in the left anterior circulation (LtAC) in 101 (45.5%) patients, and 8-F GCs were the most frequently used (40.1%). TRA-NET achieved a 95.0% success rate, with a switch to TFA required in 5.0% of the cases. Procedural challenges occurred in 42 (18.9%) patients, primarily in those with LtAC lesions. Specifically, a type III aortic arch (p <0.0001) and age ≥80 years (p = 0.01) were significantly associated with procedural difficulties. Radial artery evaluation was confirmed in 66 cases (29.7%), revealing one instance (1.5%) of radial artery occlusion. No severe puncture-site complications were observed.

Conclusion

TRA-NET may provide substantial therapeutic benefits without significant limitations in device use. However, it may be challenging, particularly in older patients and those with a type III aortic arch with LtAC lesions. Consequently, careful selection of the approach route is imperative.

Transradial versus transfemoral access for posterior circulation endovascular intervention: A systematic review and meta-analysis

OBJECTIVE

Transradial access (TRA) provides a more direct entry to posterior circulation system for endovascular therapy compared to transfemoral access (TFA). This meta-analysis aims to evaluate the safety and feasibility of TRA in neurointervention of posterior circulation.

MATERIALS AND METHODS

A systematic search was conducted in the Wanfang Data, CBM, PubMed, Embase, Cochrane Library, Web of Science databases. The primary outcomes included total complications and access site complications. Secondary outcomes were single puncture success, procedural success, access cross-over, catheter retention time and fluoroscopy time.

RESULTS

Six studies encompassing 297 patients were included in the meta-analysis. Compared to the TFA group, the TRA group showed significantly decreased total complications (odds ratio [OR] = 0.29, 95% confidence interval [CI] [0.12, 0.73], p < 0.01) and access site complications (OR = 0.19, 95%CI [0.06, 0.62], p < 0.01), yet it had a longer catheter retention time (mean difference [MD] = 0.80, 95%CI [0.60, 1.00], p < 0.01). There were no significant differences in single puncture success (OR = 3.68, 95%CI[0.38, 35.86], p = 0.26), procedural success (OR = 0.30，95%CI [0.05, 1.73], p = 0.18), access cross-over (OR = 2.29, 95%CI [0.19, 28.26], p = 0.52), fluoroscopy time (MD = 0.97, 95%CI [- 0.91, 2.84], p = 0.31) between the TRA and TFA groups.

CONCLUSION

This meta-analysis demonstrated that TRA is a safe and feasible alternative to TFA for neurointervention in the posterior circulation. TRA showed significantly decreased total complications and access site complications, yet it had a longer catheter retention time than TFA.

Simplified Transradial Access for Aneurysms Treatment: A Guiding System Using Solo Distal Access Catheter and Anatomical Considerations

OBJECTIVE

The recent shift from transfemoral access to transradial access in neurointervention has led to gaps in guiding systems. We propose a useful guiding system, the solo distal access catheter system without a conventional guiding catheter or a sheath in transradial access for aneurysms treatment. We also assessed the anatomical features required for suitable patient selection.

METHODS

We retrospectively collected data from consecutive patients with aneurysms treated with the solo distal access catheter system at our institution between April 2022 and April 2023, and evaluated the anatomical factors that appeared to affect the procedure.

RESULTS

Of the 20 patients who underwent transradial access, 11 were treated using the solo distal access catheter system, and 10 (90.9%) completed the procedure. No radial artery occlusion was detected. The entry angle of the target vessel ranged from 37° to 139°, and the mean proximal parent artery diameter was 9.34 ± 1.48 mm. A double subclavian innominate curve was observed in 3 of 5 patients whose target vessels were the right common carotid artery.

CONCLUSIONS

Using a solo distal access catheter as a guiding system for treating aneurysm proved effective and feasible with appropriate patient selection. Anatomical assessment of the entry angle of the target vessel, proximal parent artery diameter, and tortuosity may be important factors for the success of this method.

Therapeutic efficacy and complications of radial versus femoral access in endovascular treatment of unruptured intracranial aneurysms

PURPOSE

The transradial approach (TRA) in neuroendovascular treatment is known to have a lower risk of complications than the transfemoral approach (TFA). However, little research has focused on assessments of efficacy and risk of complications in the treatment of intracranial aneurysms. This study aimed to compare the efficacy and complications of TRA and TFA in coil embolization of unruptured intracranial aneurysms (UIAs) at our institution.

METHODS

Consecutive patients who underwent endovascular surgery via TRA or TFA at a single institution from 1 April 2019, to 28 February 2022, were retrospectively analyzed. Patients were classified into TRA and TFA groups and assessed using propensity-adjusted analysis for outcomes including fluoroscopy time, volume embolization ratio (VER), and complications.

RESULTS

A total of 163 consecutive UIAs were treated with coil embolization during the 35-months study period. The incidence of minor access site complications (ASCs) was significantly higher with TFA (20%, 25/126) than with TRA (2.7%, 1/37; p = 0.01). Propensity-adjusted analysis (matched for age, sex, aneurysm volume, embolization technique, and sheath size) revealed that TRA was associated with a lower risk of minor ASCs (odds ratio, 0.085; 95% confidence interval 0.0094-0.78; p = 0.029). However, TRA did not differ significantly from TFA with respect to fluoroscopy time, VER, major ASCs, and non-ASCs.

CONCLUSIONS

Coil embolization for UIAs via TRA can reduce risk of minor ASCs without increasing the risk of non-ASCs compared with conventional TFA, and can achieve comparable results in term of efficacy and fluoroscopy time.

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.

Risk factors for radial artery occlusion after neurointervention for unruptured intracranial aneurysm via transradial access

PURPOSE

Neurointervention via transradial access (TRA) is less invasive than via transfemoral access. However, radial artery occlusion (RAO) may occur with TRA. The purpose of this study was to explore risk factors for RAO after coil embolization of unruptured intracranial aneurysms (UIAs) via TRA.

METHODS

Forty-two consecutive patients who underwent coil embolization for UIAs via TRA between March 2021 and March 2022 and were available for angiographic evaluation 1 year after treatment were retrospectively reviewed. Multivariate logistic regression analysis was conducted to identify potential risk factors for RAO.

RESULTS

Seventeen (40%) of the 42 patients showed RAO. Compared with the non-RAO group, radial artery size was significantly smaller (2.2 mm [interquartile range (IQR): 2.1, 2.4 mm] vs 2.6 mm [IQR: 2.5, 2.7 mm]; p = 0.001) and the incidence of radial artery spasm (RAS) was significantly higher in the RAO group. Multivariate analysis identified radial artery size (odds ratio [OR] 4.9 × 10^-3, 95% confidence interval [CI] 6.4 × 10^-5-0.38) and incidence of RAS (OR 14.8, 95%CI 2.1-105) as significant independent predictors of subsequent RAO. Based on receiver operating characteristic (ROC) curve analysis, the optimal cutoff for radial artery size was 2.5 mm (sensitivity, 82.4%; specificity, 76.0%; area under the ROC curve, 0.80 [95%CI 0.66-0.95]).

CONCLUSION

Radial artery size and RAS represent reliable parameters for predicting RAO 1 year after coil embolization for UIA via TRA. Prophylaxis against RAS and limiting neurointervention via TRA to patients with radial artery larger than 2.5 mm in diameter may reduce the risk of postoperative RAO.

Predicting difficult transradial approach guiding into left internal carotid artery on unruptured intracranial aneurysms

BACKGROUND

The transradial approach (TRA) is less invasive than the transfemoral approach (TFA), but the higher conversion rate represents a drawback. Among target vessels, the left internal carotid artery (ICA) is particularly difficult to deliver the guiding catheter to through TRA. The purpose of this study was thus to explore anatomical and clinical features objectively predictive of the difficulty of delivering a guiding catheter into the left ICA via TRA.

METHODS

Among 78 consecutive patients who underwent coil embolization for unruptured intracranial aneurysms through TRA in a single institution between March 1, 2021, and August 31, 2022, all 29 patients (37%) who underwent delivery of the guiding catheter into the left ICA were retrospectively analyzed. Clinical and anatomical features were analyzed to assess correlations with difficulty in guiding the catheter into the left ICA.

RESULTS

Of the 29 aneurysms requiring guidance of a catheter into the left ICA, 9 aneurysms (31%) required conversion from TRA to TFA. More acute innominate-left common carotid artery (CCA) angle (P < 0.001) and older age (P = 0.015) were associated with a higher conversion rate to TFA. Receiver operating characteristic analysis revealed that optimal cutoff values for the innominate-left CCA angle and age to distinguish between nonconversion and conversion to TFA were 16° (area under the curve [AUC], 0.93; 95% confidence interval [CI], 0.83-1.00) and 74 years (AUC, 0.79; 95% CI, 0.61-0.96), respectively.

CONCLUSION

A more acute innominate-left CCA angle and older age appear associated with difficulty delivering the guiding catheter into the left ICA for neurointervention through TRA.

Left Distal Transradial Approach for the Treatment of a Sacral Extradural Arteriovenous Fistula: A Technical Note and Literature Review

BACKGROUND

Sacral extradural arteriovenous fistula (SEAVF) is relatively rare, and its etiology is unknown. They are mostly fed by the lateral sacral artery (LSA). For endovascular treatment, both the stability of the guiding catheter and accessibility of the microcatheter to the fistula, distal to the LSA are required for sufficient embolization of the fistulous point. Cannulation of these vessels requires either crossover at the aortic bifurcation or retrograde cannulation using the transfemoral approach. However, atherosclerotic femoral and tortuous aortoiliac vessels can make the procedure technically difficult. Although the right transradial approach (TRA) can reduce this difficulty by straightening the access route, a potential risk remains for cerebral embolism because it passes the aortic arch. Herein, we present a case of successful embolization of a SEAVF using a left distal TRA.

METHODS

We report a case of a 47-year-old man with SEAVF treated with embolization using a left distal TRA. Lumbar spinal angiography showed a SEAVF with an intradural vein through the epidural venous plexus fed by the left LSA. A 6-French guiding sheath was cannulated into the internal iliac artery via the descending aorta using the left distal TRA. A microcatheter could be advanced into the extradural venous plexus over the fistula point from the intermediate catheter placed at the LSA. Embolization with coils and n-butyl cyanoacrylate was successfully performed.

RESULTS

The SEAVF completely disappeared on neuroimaging, and the patient gradually recovered.

CONCLUSIONS

Left distal TRA could be a useful, safe, and less invasive option for the embolization of SEAVF, especially for patients with high-risk factors for aortogenic embolism or puncture site complications.

Transradial balloon guide catheter placement for acute ischemic stroke thrombectomy: A systematic review and meta-analysis

BACKGROUND

Endovascular thrombectomy (EVT) is a treatment option for acute ischemic stroke due to large vessel occlusion. The use of a balloon-guided catheter (BGC) for EVT via transradial access (TRA) has emerged as a treatment approach, but its efficacy and safety compared to existing practices are uncertain.

METHODS

A systematic literature review was performed using Embase, PubMed, Scopus, Web of Science databases, and manual search. Studies reporting safety and efficacy metrics for TRA BGC EVT were included. Data regarding recanalization time, thrombolysis in cerebral infarction (TICI), modified Rankin scale (mRS), symptomatic intracranial hemorrhage (sICH), first pass effect (FPE), and additional complications was pooled using a random-effects model to calculate event rates and 95% confidence intervals (CI).

RESULTS

The search yielded five studies (n  =  117). The mean time from puncture to final recanalization was 34.5 (95% CI  =  30.5 to 39.14, I²  =  0%, P-value  =  0.37) min. Successful recanalization (TICI 2b-3) and complete recanalization (TICI 3) occurred in 96.6% (95% CI  =  91.24 to 98.71, I²  =  0%, P-value  =  0.99) and 55.2% (95% CI  =  42.14 to 67.54, I²  =  0%, P-value  =  0.39) of cases, respectively. FPE occurred in 67.5% (95% CI  =  51.73 to 80.10, I²  =  0%, P-value  =  0.56) of patients. mRS 0-2 was achieved in 41.2% (95% CI  =  27.34 to 56.65, I²  =  70%, P-value  =  0.07) of patients. sICH occurred in 5.0% (95% CI  =  1.25 to 17.91, I²  =  0%, P-value  =  1.00) of patients. Local complications of radial hematoma and radial vasospasm occurred in 5.0% (95% CI  =  0.49 to 12.36, I²  =  29%, P-value  =  0.24) and 2.1% (95% CI  =  1.25 to 17.91, I²  =  71%, P-value  =  0.03) of cases, respectively. Switch to femoral access was necessary in 3.7% (95% CI  =  0.00 to 14.07, I²  =  68%, P-value  =  0.02) of procedures. The average number of passes per procedure was 1.6 (95% CI  =  1.15 to 2.11, I²  =  88%, P-value < 0.001).

CONCLUSION

TRA BGC EVT has potential as a safe and efficacious treatment option compared to existing methods. However, additional, prospective studies are necessary to inform clinical decision making.

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.

Use of reverse angle guide catheter with trans-radial approach in patients undergoing middle meningeal artery embolization

Background

Trans-radial access (TRA) for MMA embolization has grown due to lower access site complications and greater patient satisfaction. Here, we describe the feasibility of utilizing a 6F Envoy Simmons 2 (6F-SIM2) as a guide catheter with TRA and compare outcomes with trans-femoral approach (TFA) in a single center case series.

Methods

We performed a retrospective review of patients who underwent MMA embolization for management of chronic subdural hematoma (cSDH). TRA was performed by utilizing a combination of 6F 90cm Envoy (Codman &amp; Shurtleff, Inc., Rayham, MA) Simmons 2 guide catheter and 5F 125cm Sofia (Microvention, Aliso Viejo, CA) intermediate catheter. Outcomes measured are Modified Rankin Score (mRS) at 90 days, inpatient mortality, post-embolization recurrence, fluoroscopy time and radiation exposure.

Results

A total of 71 patients underwent 97 MMA embolization overall with 65 (67%) in trans-femoral access group, 11 (11.3%) in trans-radial access without use of Simmons 2 Guide catheter group and 21 (21.6%) in trans-radial access with use of Simmons 2 Guide catheter group. There were no direct access-related complications in either group. One patient had thromboembolic stroke in trans-femoral group. There was no difference in average procedure-related total fluro time or radiation dose among all three groups.

Conclusion

Trans-radial approach using 6F-SIM2 guide catheter coupled with 5F Sofia intermediate catheter is safe and effective. It provides an alternative approach to access distal branches of bilateral anterior circulation in elderly patients with difficult anatomy undergoing MMA embolization.

Transradial versus transfemoral access for embolization of intracranial aneurysms with the Woven EndoBridge device: a propensity score-matched study

OBJECTIVE

Transradial access (TRA) is commonly utilized in neurointerventional procedures. This study compared the technical and clinical outcomes of the use of TRA versus those of transfemoral access (TFA) for intracranial aneurysm embolization with the Woven EndoBridge (WEB) device.

METHODS

This is a secondary analysis of the Worldwide WEB Consortium, which comprises multicenter data related to adult patients with intracranial aneurysms who were managed with the WEB device. These aneurysms were categorized into two groups: those who were treated with TRA or TFA. Patient and aneurysm characteristics and technical and clinical outcomes were compared between groups. Propensity score matching (PSM) was used to match groups according to the following baseline characteristics: age, sex, subarachnoid hemorrhage, aneurysm location, bifurcation aneurysm, aneurysm with incorporated branch, neck width, aspect ratio, dome width, and elapsed time since the last follow-up imaging evaluation.

RESULTS

This study included 682 intracranial aneurysms (median [interquartile range] age 61.3 [53.0-68.0] years), of which 561 were treated with TFA and 121 with TRA. PSM resulted in 65 matched pairs. After PSM, both groups had similar characteristics, angiographic and functional outcomes, and rates of retreatment, thromboembolic and hemorrhagic complications, and death. TFA was associated with longer procedure length (median 96.5 minutes vs 72.0 minutes, p = 0.006) and fluoroscopy time (28.2 minutes vs 24.8 minutes, p = 0.037) as compared with TRA. On the other hand, deployment issues were more common in those treated with TRA, but none resulted in permanent complications.

CONCLUSIONS

TRA has comparable outcomes, with shorter procedure and fluoroscopy time, to TFA for aneurysm embolization with the WEB device.

Feasibility and Safety of Transradial Aneurysm Embolization: A Systematic Review and Meta-Analysis

OBJECTIVE

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.

METHODS

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.

RESULTS

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%).

CONCLUSIONS

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

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.

Surgical exposure of the vertebral artery for endovascular access in a hybrid operating room

PURPOSE

Endovascular procedures are a desirable treatment option for neurovascular lesions in posterior circulation. However, endovascular access occasionally fails due to tortuosity of the proximal vertebral artery (VA), aortic arch, and/or VA ostium stenosis. We aimed to describe the creation of endovascular access via surgical exposure of the VA in a hybrid operating room to overcome anatomical difficulties hampering distal access to the VA through the transfemoral or transradial approach.

METHODS

We present six patients with seven posterior circulation lesions in whom distal access via the conventional approach to the VA was impossible. Surgical exposure of the VA was performed to provide endovascular access to these patients. Radiographic characteristics, operative techniques, and outcomes were reviewed.

RESULTS

Surgical exposure of the VA was performed in six patients with cerebral aneurysm (n = 4) and symptomatic stenosis of the VA ostium (n = 3). There were four female and two male patients, aged 73-82 years. Surgical exposure was usually performed beyond the tortuous segments of the VA. After endovascular access was provided, coil embolization was performed for cerebral aneurysms and/or balloon angioplasty and stenting was performed to treat the VA ostium stenosis. All puncture sites were closed by direct suture using a 7-0 Prolene suture. All procedures were completed without adverse events.

CONCLUSION

Endovascular access via surgical exposure of the VA is a feasible and safe alternative for patients in whom the femoral or radial route does not allow the navigation and stabilization of the guiding catheter into the proximal segment of the VA.

Avoiding the Radial Paradox: Neuroendovascular Femoral Access Outcomes After Radial Access Adoption

BACKGROUND

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."

OBJECTIVE

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

METHODS

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

RESULTS

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).

CONCLUSION

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.

Initial Experience with Left Transradial Neurointerventions for Cerebral Aneurysms Using the 6-French Simmons Guiding Sheath

OBJECTIVE

The use of a transradial approach utilizing a Simmons-shaped catheter for neurointervention has been steadily increasing. Although the right radial artery is commonly used, in interventional cardiology, the left transradial approach offers clear clinical benefits for right-handed patients. To the best of our knowledge, no previous studies have examined intracranial aneurysm embolization with the routine use of the left transradial approach. The aim of this study was to evaluate the technical feasibility of left transradial intracranial aneurysm embolization.

METHODS

We conducted a retrospective review of a prospective database of consecutive patients who had undergone left transradial intracranial aneurysm coiling using a 6-French Simmons guiding sheath between January and August 2021. The following outcome variables were then analyzed: whether the catheterization was successful, the angiographical results, and the presence of any procedure-related complications.

RESULTS

In total, 25 patients underwent left transradial coiling for 15 anterior and 10 posterior circulation aneurysms. The Simmons guiding sheath could be successfully shaped and cannulated into the targeted vessel in all patients. All aneurysms were completely embolized without any complications. Immediate postoperative angiograms showed Raymond 1 in 10 aneurysms (40.0%), Raymond 2 in 12 (48.0%), and Raymond 3a in 3 (12.0%). None of the patients required crossover to the right radial or femoral arteries, and no radial artery spasms or occlusions were observed.

CONCLUSION

The results of this study suggest that the left transradial approach for intracranial aneurysm coiling is not only safe, effective, and technically feasible, but also provides improved comfort to right-handed patients.

Safety and feasibility of transradial use of 8F balloon guide catheter Flowgate2 for endovascular thrombectomy in acute ischemic stroke

BACKGROUND

While Balloon Guide Catheters (BGC) have been shown to increase the rate of reperfusion during mechanical thrombectomy (MT), its implementation with transfemoral approach is at times limited due to unfavorable vascular anatomy.

OBJECTIVE

to determine safety, feasibility and performance of the transradial use of 8 F BGC Flowgate² during mechanical thrombectomy procedures in patients with unfavorable vascular anatomies (type 3 or bovine arch)Material/Methods: We performed a retrospective cohort study of consecutive transradial mechanical thrombectomies performed with BGC Flowgate² between January and December 2019. Patient demographics, procedural and radiographic metrics, and clinical data were analyzed.

RESULTS

20 (8.7%) out of 230 overall thrombectomy procedures underwent transradial approach using an 8 F BGC Flowgate.² Successful approach was achieved in 17/20 cases, and in 3 cases radial was switched to femoral, after failure. TICI 2 C/3 was achieved in 18 cases (90%), followed by TICI 2 b and 2a in 1 (5%) case respectively. The average number of passes was 1.8. The average radial puncture-to-first pass time was 22 min. Radial vasospasm was observed in 3/20 cases. The Flowgate² was found kinked in 4/20 cases (20%), all of them during right internal carotid procedures. There were no postprocedural complications at puncture site, as hematoma, pseudoaneurysm or local ischemic events.

CONCLUSION

The use of 8 F Balloon Guide Catheter during MT via transradial approach might represent an alternative in selected cases with unfavorable vascular anatomies. Its use in right ICA catheterizations was associated with a high rate of catheter kinking.

Anatomical factors that impede using the radial artery approach for carotid artery revascularization

OBJECTIVES

We investigated the anatomical characteristics that complicate utilizing the radial artery approach (RAA) for craniocervical intravascular intervention.

METHODS

The data of 73 lesions in consecutive 65 patients who underwent transradial cervical carotid artery intervention was evaluated. We assessed the success rate of RAA in right-sided and left-sided lesions. The diameters and angles of the left and right common carotid arteries and the aortic, brachiocephalic, and right subclavian arteries, which comprise the paths of the guiding sheath, were assessed for each of the left- and right-sided lesions.

RESULTS

It was difficult to apply RAA in 10 cases (13.7%), of which 2 (5.0%) involved right-sided and 8 (24.2%) left-sided lesions. The approach was significantly more difficult to perform in left-sided than in right-sided lesions (p=0.02). Although the treatments were successfully completed, crossover to the femoral artery approach was required in four cases (5.5%, 2 cases for left-sided lesions). Placement of the guiding sheath in the common carotid artery was successful for all right-sided lesions; however, the guiding sheath slipped off to the aorta during stent advancement in two cases. When the angle between the brachiocephalic artery and aortic arch was small, the introduction of the guiding sheath to left-sided lesions was difficult in eight cases (p=0.0001).

CONCLUSIONS

RAA was difficult to perform in cases involving left-sided lesions and a small angle between the brachiocephalic artery and aortic arch. This study could help delineate the factors associated with difficulty of catheter introduction and instability of RAA.

Transradial quadraxial system for coil embolization of distal anterior cerebral artery aneurysms: A radial-first center case series and literature review

PURPOSE

Endovascular treatment is technically challenging as distal anterior cerebral artery (DACA) aneurysms have distal location, small-caliber parent artery, and small size/wide neck. This study evaluated the feasibility and safety of the transradial approach (TRA) with a radial-specific neurointerventional guiding sheath as the first-line technique for DACA aneurysms.

METHODS

We retrospectively analyzed an institutional database of consecutive patients with DACA aneurysm who underwent coil embolization using TRA. Ten consecutive patients were included in this study. After the radial-specific 6F Simmons guiding sheath (0.088″ inner diameter) was completely engaged into the target common carotid artery, a quadraxial system (6F Simmons guiding sheath/6F intermediate catheter/3.2F intermediate catheter/single microcatheter) was used for embolization. Then, we assessed for procedural success, angiographic outcomes, and procedure-related or vascular access site complications.

RESULTS

Embolization procedures were conducted using simple coiling in eight and stent-assisted coiling with the trans-cell approach in two patients. The embolization procedure was successful in all patients (n = 10). Moreover, none presented with catheter kinking, parent artery flow stagnation, or system instability during the procedure. Immediate postprocedural angiography revealed complete obliteration in six and residual neck in four patients. Then, eight patients underwent follow-up angiography at a mean of 7.1 months, and none developed recanalization or required retreatment. The postprocedural course was uneventful, and there were no complications.

CONCLUSION

The transradial quadraxial system had the ability to achieve sufficient stability and kink resistance in DACA aneurysm embolization. Thus, this method was feasible and safe and had a high success rate.

A comparison of radial versus femoral artery access for acute stroke interventions

OBJECTIVE

In this study, the authors aimed to investigate procedural and clinical outcomes between radial and femoral artery access in patients undergoing thrombectomy for acute stroke.

METHODS

The authors conducted a single-institution retrospective analysis of 104 patients who underwent mechanical thrombectomy, 52 via transradial access and 52 via traditional transfemoral access. They analyzed various procedural and clinical metrics between the two patient cohorts.

RESULTS

There was no difference between patient demographics or presenting symptoms of stroke severity between patients treated via transradial or transfemoral access. The mean procedural time was similar between the two treatment cohorts: 60.35 ± 36.81 minutes for the transradial group versus 65.50 ± 29.92 minutes for the transfemoral group (p = 0.451). The mean total fluoroscopy time for the procedure was similar between the two patient cohorts (20.31 ± 11.68 for radial vs 18.49 ± 11.78 minutes for femoral, p = 0.898). The majority of patients underwent thrombolysis in cerebral infarction score 2b/3 revascularization, regardless of access site (92.3% for radial vs 94.2% for femoral, p = 0.696). There was no significant difference in the incidence of access site or periprocedural complications between the transradial and transfemoral cohorts.

CONCLUSIONS

Acute stroke intervention performed via transradial access is feasible and effective, with no significant difference in procedural and clinical outcomes compared with traditional transfemoral access. Larger studies are required to further validate the efficacy and limitations of transradial access for neurointerventional procedures.

Use of a sheathless 8-French balloon guide catheter (Walrus) through the radial artery for mechanical thrombectomy: technique and case series

BACKGROUND

The effectiveness of transradial stroke thrombectomy has been limited by guide catheter size and lack of good balloon options. In this study we describe our technique for the use of a sheathless 8-French balloon guide catheter (Walrus) through radial access and present our initial clinical experience.

METHODS

This was a retrospective case series of consecutive patients who underwent mechanical thrombectomy for large vessel occlusion using the sheathless catheter over a period of 3 months. Clinical characteristics, procedural details, reperfusion success (modified Thrombolysis in Cerebral Infarction (mTICI) 2b-3 grade), first-pass effect (FPE; mTICI reperfusion grade 2c or 3 with a single pass), access site complications and clinical improvement at discharge were recorded. A descriptive analysis was performed.

RESULTS

Among the 10 patients in the series, median age was 77 years (IQR 75-79) and three were women. All patients had a baseline modified Rankin Scale score ≤2. Median admission National Institutes of Health Stroke Scale (NIHSS) score was 12.5 (IQR 9-16). Four patients received intravenous alteplase before mechanical thrombectomy. Eight patients had M1 occlusion and two had proximal M2 occlusion. The median radial artery diameter was 2.5 mm (IQR 2.5-2.7). Successful reperfusion was achieved in all patients. FPE was achieved in six patients. No access site-related complications or post-procedural intracranial hemorrhages occurred. All patients had improvement in NIHSS score at discharge.

CONCLUSIONS

The use of this sheathless catheter for transradial access was safe and feasible. The technique can potentially improve the outcomes of transradial access for stroke intervention.

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.

Propensity-Adjusted Comparative Analysis of Radial Versus Femoral Access for Neurointerventional Treatments

BACKGROUND

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.

OBJECTIVE

To compare TRA and TFA approaches for cerebrovascular interventions.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Dual-center study comparing transradial and transfemoral approaches for flow diversion treatment of intracranial aneurysms

BACKGROUND

The transfemoral approach (TFA) has been the traditional approach for neurointerventional cases. While the TFA allows for triaxial support in flow diverting stent cases, it is associated with access site complications. Recently, the transradial approach (TRA) has emerged as a safer alternative to the TFA. To the best of our knowledge, there have only been single-center studies comparing outcomes in flow diverter cases for these approaches. We demonstrate the safety and feasibility of the TRA for placement of flow diverting stents in the treatment of unruptured intracranial aneurysms at two high-volume centers.

MATERIALS AND METHODS

We performed a retrospective review of prospectively collected institutional databases at two high-volume neuroendovascular centers. Cases from 2016 to 2018 of unruptured intracranial aneurysms treated by flow diverting stenting accessed through either the TRA or the TFA were compared. Patient demographics, procedural and radiographic metrics including location and size of the aneurysm, size, and length of the flow diverter implant, and fluoroscopic time were recorded. Puncture site complications and length of hospital stay were also included in the data analysis.

RESULTS

There were three out of 29 TRA cases which were converted to the TFA. None of the TRA patients experienced site complications, whereas three TFA patients experienced site complications. While TRA and TFA patients did not differ significantly in their exposure to radiation, TRA patients experienced shorter hospital stays.

CONCLUSIONS

While long-term studies are still lacking regarding this approach, we demonstrate that the TRA is a safe and feasible approach for flow diverter stent placement.

Systematic Review of Transradial Access for Flow Diversion of Intracranial Aneurysms

BACKGROUND

Transradial access is an increasingly popular route for cerebral angiography and neurointerventions. However, obstacles to wider adoption remain, especially for complex interventions typically performed with larger, multiaxial systems such as flow diversion. We sought to analyze the published evidence for transradial flow diversion of intracranial aneurysms.

METHODS

Using Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines, a literature review was performed to identify all published reports and studies of transradial flow diversion for intracranial aneurysm. The search was limited from April 2011 to February 2021. Primary outcome was successful completion of the procedure via a transradial approach. Heterogeneity was analyzed with Q and I² statistics. Secondary outcomes were transradial access-site complications and other complications.

RESULTS

In total, 11 studies involving 290 treated aneurysms were identified; 90.7% of the procedures were completed via the transradial approach. The heterogeneity between studies was high, with an I² of 56.9%. There were no transradial access-site complications. The procedural complication rate was 2.41%.

CONCLUSIONS

Transradial access has a high success rate for both anterior and posterior circulation flow-diversion embolizations. The success rate may be particularly high for posterior circulation and right anterior circulation aneurysms. It has a negligible access-site complication rate. Transradial access is a viable alternative to transfemoral access for flow diversion and should be considered as a first-line approach.

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.

Distal Access Catheters for Coaxial Radial Access for Posterior Circulation Interventions

BACKGROUND

The neurointerventional field is moving towards transradial access (TRA). Among the favorable indications for TRA is for posterior circulation/vertebrobasilar interventions. For some neurointerventions, a triaxial system (guide catheter, distal access catheter [DAC], and microcatheter) is typically used for optimal support. We describe application of a new technique in which we forgo use of the guide catheter, using the DAC only for coaxial access via the radial approach and its potential advantages.

METHODS

A retrospective review was performed of our institutional database for cases using our coaxial distal access catheter technique for posterior circulation interventions. Patient characteristics and radiographic and clinical information were reviewed. All reviews were approved by institutional review board and ethics committee, and all patient identifiers were removed.

RESULTS

A total of 12 patients were found that met our criteria. Successful access and procedural completion was achieved in 11 of 12 (92%). Mechanical thrombectomy accounted for 7 cases; 2 of these patients were also stented via the same approach/technique. Other cases included 2 successful aneurysm treatments (1 flow diverter, 1 coil embolization), a balloon test occlusion for a cervical chordoma, and an arteriovenous malformation embolization.

CONCLUSIONS

TRA with a distal access catheter provides support equivalent to a triaxial system with a coaxial construct in the posterior circulation. This has the advantage of using a smaller system in the radial and vertebrobasilar artery without losing stability. This technique can be used effectively and safely for a variety of posterior circulation neuroendovascular interventions.

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.

Endovascular management of radial artery loop for neuroangiography: Case series

Background

Radial loops are rare congenital radial artery anomalies that may pose a significant challenge to successful transradial neuroangiography. In this case series, we describe the anatomy and frequency of radial artery loops and provide a technique for successful navigation of this anatomic anomaly.

Methods

We reviewed our database of radial diagnostic or interventional neuroangiographic procedures to identify cases in which a radial loop was encountered during the procedure. The loop pattern, the presence of an associated recurrent radial artery branch, navigation technique, and procedure-related complications were recorded. A descriptive analysis was performed.

Results

A total of 997 transradial approach procedures were performed over a 9-month period. A radial loop was identified in 10 (1.0%) patients. The average age was 68.6 ± 14.3 years. A microcatheter advanced over a microwire was used to navigate the loop and avoid entry into the recurrent branch. A diagnostic neuroangiographic procedure was performed successfully in 8 cases and an intervention was performed successfully in 1 case. A 360° loop was present in 2 of these cases. In each case, transradial access was performed successfully. In 1 other diagnostic case, transradial access was aborted, and the femoral artery was accessed to perform the procedure.

Conclusions

A radial loop was present in 1% of the cases in this series. Our technical results suggest that this anomaly should not be considered a contraindication to transradial neuroangiography because the procedure was successfully performed in most (9 of 10) cases using a microcatheter system to navigate the loop.

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.

Bilateral Transradial Approach for Coil Embolization of Basilar Artery Aneurysms Associated with an Unfavorable Vertebral Artery Anatomy : Initial Experience with Role-sharing Technique

PURPOSE

An unfavorable vertebral artery (VA) anatomy occasionally inhibits a successful VA cannulation due to flow stagnation after catheterization. To preserve antegrade VA flow, we developed bilateral transradial catheter systems, referred to as the role-sharing technique, for coil embolization of basilar artery (BA) aneurysms associated with an unfavorable VA anatomy. This study aimed to evaluate the feasibility and safety of coil embolization using the role-sharing technique for BA aneurysms.

METHODS

We retrospectively analyzed an institutional database of consecutive patients with BA aneurysm who underwent coil embolization using the role-sharing technique between July 2019 and January 2020. The study included seven consecutive patients. Bilateral transradial VA cannulation was performed using 3.2F catheters (TACTICS; Technocrat Corporation, Aichi, Japan) via 4F guiding sheaths placed in the subclavian artery. The following catheter systems were used: the triaxial system (4F guiding sheath/TACTICS/coil or stent delivery microcatheter) that has a specialized role in embolization and the biaxial system (4F guiding sheath/TACTICS) that has a specialized role in contrast injection during embolization procedure. The procedural success and procedure-related or vascular access site complications were assessed.

RESULTS

All patients underwent a successful embolization procedure using the bilateral transradial catheter systems and none of them presented with flow stagnation, system instability, or other complications.

CONCLUSION

The role-sharing technique was shown to be a feasible and safe method for coil embolization of BA aneurysms associated with an unfavorable VA anatomy. This method may increase the success rate of transradial coil embolization for BA aneurysms.

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.

Propensity-adjusted cost analysis of radial versus femoral access for neuroendovascular procedures

BACKGROUND

Transradial artery (TRA) access for neuroendovascular procedures is associated with fewer complications than transfemoral artery (TFA) access. This study compares hospital costs associated with TRA access to those associated with TFA access for neurointerventions.

METHODS

Elective neuroendovascular procedures at a single center were retrospectively analyzed from October 1, 2018 to May 31, 2019. Hospital costs for each procedure were obtained from the hospital financial department. The primary outcome was the difference in the mean hospital costs after propensity adjustment between patients who underwent TRA compared with TFA access.

RESULTS

Of the 338 elective procedures included, 63 (19%) were performed through TRA versus 275 (81%) through TFA access. Diagnostic procedures were more common in the TRA cohort (51 of 63, 81%) compared with the TFA cohort (197 of 275, 72%), but the difference was not significant (p=0.48). The TRA cohort had a shorter length of hospital stay (mean (SD) 0.3 (0.5) days) compared with the TFA cohort (mean 0.7 (1.3) days; p=0.02) and lower hospital costs (mean $12 968 ($6518) compared with the TFA cohort (mean $17 150 ($10 946); p=0.004). After propensity adjustment for age, sex, symptoms, angiographic findings, procedure type, sheath size, and catheter size, TRA access was associated with a mean hospital cost of $2514 less than that for TFA access (95% CI -$4931 to -$97; p=0.04).

CONCLUSION

Neuroendovascular procedures performed through TRA access are associated with lower hospital costs than TFA procedures. The lower cost is likely due to a decreased length of hospital stay for TRA.

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.

Distal radial artery (snuffbox) access for carotid artery stenting - Technical pearls and procedural set-up

PURPOSE

To report use of distal radial artery (dRA) access for carotid artery stenting (CAS) and to discuss procedural setup and technical considerations for a successful intervention.

METHODS

A retrospective review of our prospective neurointerventional database of CAS was conducted between May 2019 and March 2020. All CAS cases via dRA in the anatomical snuffbox were identified. Patient demographics, clinical information, procedural and radiographic data was collected.

RESULTS

22 CAS procedures in 20 patients via dRA were identified. Patients' mean age was 69.4 years (range 53-87 years). 3 patients were female. Mean radial artery diameter was 2.1 mm (range 1.6-2.8 mm). dRA access was achieved in all cases. Conversion to femoral access was required in 2 cases (9.1%) due to persistent radial artery vasospasm resulting in patient discomfort despite multiple additional doses of intraarterial vasodilators and added intravenous sedation as well as tortuous vessel anatomy and limited support of the catheters in a type 3 aortic arch for left CAS.

CONCLUSION

Our preliminary experience with dRA access for CAS suggests this approach to be feasible and safe for patients. Technical considerations are important and preprocedural planning is necessary for a successful intervention. Catheter systems and devices specifically designed for radial access are needed to enable more interventionalists to safely perform neurointerventional procedures via wrist access.

Distal radial artery (snuffbox) access for carotid artery stenting - Technical pearls and procedural set-up

PURPOSE

To report use of distal radial artery (dRA) access for carotid artery stenting (CAS) and to discuss procedural setup and technical considerations for a successful intervention.

METHODS

A retrospective review of our prospective neurointerventional database of CAS was conducted between May 2019 and March 2020. All CAS cases via dRA in the anatomical snuffbox were identified. Patient demographics, clinical information, procedural and radiographic data was collected.

RESULTS

22 CAS procedures in 20 patients via dRA were identified. Patients' mean age was 69.4 years (range 53-87 years). 3 patients were female. Mean radial artery diameter was 2.1 mm (range 1.6-2.8 mm). dRA access was achieved in all cases. Conversion to femoral access was required in 2 cases (9.1%) due to persistent radial artery vasospasm resulting in patient discomfort despite multiple additional doses of intraarterial vasodilators and added intravenous sedation as well as tortuous vessel anatomy and limited support of the catheters in a type 3 aortic arch for left CAS.

CONCLUSION

Our preliminary experience with dRA access for CAS suggests this approach to be feasible and safe for patients. Technical considerations are important and preprocedural planning is necessary for a successful intervention. Catheter systems and devices specifically designed for radial access are needed to enable more interventionalists to safely perform neurointerventional procedures via wrist access.