Usefulness of a Novel Technique to Make Up for a Deficiency in Transradial Neurointervention with a 6Fr Simmonds Guiding Sheath: Original Experience with the Subclavian Artery Anchoring Technique

Systematic Review and Meta-Analysis of Transradial Access for Carotid Artery Stenting

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.

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.

Systematic Review and Meta-analysis of Radial or Femoral Access for Carotid Stenting

PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Left Transradial Access Using a Radial-Specific Neurointerventional Guiding Sheath for Coil Embolization of Anterior Circulation Aneurysm Associated With the Aberrant Right Subclavian Artery: Technical Note and Literature Review

BACKGROUND

Aberrant right subclavian artery (ARSA) is a rare condition, but the most common anomaly of the aortic arch. Although neurointerventions via transradial access (TRA) are becoming increasingly popular worldwide, transradial carotid cannulation has been extremely challenging in patients with an ARSA. Herein, we present a case of ARSA-associated anterior communicating artery (ACoA) aneurysm that was successfully treated with a radial-specific 6F Simmons guiding sheath via left TRA. We also review the relevant literature.

METHODS

A 68-year-old-woman who was diagnosed as having an ARSA-associated ACoA aneurysm underwent simple coiling via left TRA. After the 6F Simmons guiding sheath was engaged into the right common carotid artery using the pull-back-technique, transradial quadraxial system (6F Simmons guiding sheath/6F intermediate catheter/3.2F intermediate catheter/coil-delivery microcatheter) was implemented.

RESULTS

Simple coiling of the aneurysm was successfully achieved without catheter kinking or system instability. The postprocedural course was uneventful. A follow-up magnetic resonance angiography showed no evidence of recanalization 1 years 9 months after the procedure.

CONCLUSIONS

Transradial anterior circulation intervention has been rarely used for patients with an ARSA due to unfavorable catheter trajectory. Left TRA using the 6F Simmons guiding sheath is a useful treatment option to address anterior circulation interventions for patients with an ARSA. Preoperative diagnosis of ARSA is necessary for the application of our 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.

Real-Time Monitoring of Aneurysm Catheterization During Stent-Assisted Coiling for Irregularly Shaped Intracranial Aneurysms: The Scope Technique

OBJECTIVE

Stent-assisted coiling (SAC) using the jailing technique is a well-established treatment for wide-neck intracranial aneurysms. However, low-volume packing, which is a key factor for aneurysm recanalization, can occur in patients with irregularly shaped aneurysms. We have devised a real-time monitoring system for aneurysm catheterization that allows the intentional placement of the jailed coil-delivery microcatheter and deployed stent, referred to as the "scope" technique. Herein, we present a case of irregularly shaped anterior communicating artery (ACoA) aneurysm successfully treated with SAC using this technique.

METHODS

A 72-year-old woman diagnosed with an unruptured wide-neck ACoA aneurysm that was eccentric to the parent ACoA and overhanging posteriorly underwent SAC using this technique. Bilateral transradial quadraxial systems (6-Fr Simmons guiding sheath/6-Fr intermediate catheter/3.2-Fr intermediate catheter/microcatheter) were established via right and left internal carotid artery. The stent-delivery microcatheter was advanced into the left A2 via the right A1, leaving a 0.014″ microguidewire for visualization under fluoroscopic guidance. To place the coil-delivery microcatheter in the middle of the aneurysm after stent deployment, the coil-delivery microcatheter was cannulated into the aneurysm via the left A1, intendedly through the posterior side of the stent-delivery microcatheter in the down-the-barrel view of the parent ACoA (the scope technique).

RESULTS

After stent deployment, SAC of the aneurysm was successfully achieved.

CONCLUSIONS

Using this technique, the coil-delivery microcatheter was cannulated into the aneurysm, while monitoring its positional relationship with the stent-delivery microcatheter in real time. This technique is a useful treatment option for irregularly shaped and wide-neck aneurysms.

Real-time angiography in endovascular revascularization of intracranial atherosclerotic internal carotid artery stenosis under proximal balloon protection: "Retrograde suction-injection" technique and literature review

Intracranial angioplasty/stenting is a treatment option for patients with symptomatic intracranial atherosclerotic disease refractory to aggressive medical treatment. However, it carries a risk of procedure-related embolism as well as reperfusion hemorrhage and in-stent thrombosis. We have devised a new embolic protection system which can achieve both total ipsilateral internal carotid artery (ICA) embolic protection and real-time visualization of the target lesion during endovascular revascularization of intracranial atherosclerotic disease below the carotid T junction. Herein, we describe a case of medically refractory symptomatic intracranial atherosclerotic ICA stenosis successfully treated with this method.

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.

Transradial Stent-Assisted Coiling Using "Dual-Jailing" Technique for Kissing Aneurysms of the Internal Carotid Artery: Technical Note and Literature Review

BACKGROUND

Kissing aneurysms are an unusual type of multiple intracranial aneurysms having different origins with partially adherent walls. Although endovascular treatment is a useful alternative to surgical clipping, endovascular management for small wide-necked kissing aneurysms has not been adequately investigated to date. Herein, we present a case of small wide-necked kissing aneurysms successfully treated with transradial stent-assisted coiling (SAC) using the "dual-jailing" technique. We also performed a review of the relevant literature.

CASE PRESENTATION

A 64-year-old woman who was diagnosed with small wide-necked kissing aneurysms relating to the ophthalmic artery underwent SAC using the dual-jailing technique. After a 6F Simmons guiding sheath was delivered into the target common carotid artery via transradial access, a 6F intermediate catheter was navigated into the petrous internal carotid artery to achieve both triple microcatheter manipulation and contrast injection. Two coil-delivery microcatheters were cannulated into each aneurysm, followed by a Neuroform Atlas stent deployment over the aneurysm necks via a third stent-delivery microcatheter. By using the jailed microcatheters, SAC of the kissing aneurysms was successfully achieved, preserving the ophthalmic artery. The postprocedural course was uneventful. A follow-up magnetic resonance angiography showed no evidence of recanalization 2 years 3 months post procedure.

CONCLUSIONS

The dual-jailing technique may provide simple and time-saving SAC compared with previous reported method. This technique can be a useful treatment option for small wide-necked kissing aneurysms.

Transfemoral subclavian artery stenting through a shaped guiding catheter without pull-through technique: A case report

Transfemoral subclavian artery stenting can be challenging unless the placement of the guiding catheter is secured. Herein, we present a patient with subclavian artery stenosis treated with endovascular stenting using a shaped guiding catheter. A 79-year-old woman was admitted to our department because of a cold sensation and numbness of her left arm. Computed tomography revealed stenosis of the left subclavian artery (SA), located just proximal to the ostium of the left vertebral artery (VA). Doppler ultrasound showed reverse flow in the left VA. We planned to stent for the SA stenosis under the balloon protection of the left VA. The balloon protection device was easily navigated into the left VA through brachial access. After that, a self-expandable stent was successfully placed from just proximal to the VA origin to the ostium of the SA using a highly stable shaped guiding catheter. The patient recovered from the symptoms and was discharged 4 days after the procedure. The high stability of the shaped guiding catheter is advantageous during endovascular treatment of the subclavian artery.

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.

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.

Contralateral transradial access for coil embolization of distal anterior cerebral artery aneurysm associated with a steep ipsilateral A1-A2 angle

OBJECTIVE

Endovascular treatment of distal anterior cerebral artery aneurysms is commonly addressed via the ipsilateral A1 segment of the anterior cerebral artery. However, when the parent pericallosal artery has a sharp ipsilateral A1-A2 angle, catheterization through the ipsilateral A1 segment can potentially result in vessel injury, catheter kinking, and/or compromised/stagnant anterior cerebral artery flow. Here, we present a case of a distal anterior cerebral artery aneurysm associated with a steep ipsilateral A1-A2 angle treated with contralateral transradial coil embolization.

CASE PRESENTATION

A 91-year-old woman presented with a ruptured left distal anterior cerebral artery aneurysm at the A3 segment. The parent pericallosal artery had a steep ipsilateral A1-A2 angle. To safely achieve coil embolization of the aneurysm, a contralateral transradial system via the right A1 segment was employed. Although a secondary ipsilateral transradial system was required for contrast injection, aneurysm obliteration was successfully achieved without vessel injury or system instability.

CONCLUSION

The A1-A2 angle can be a key anatomical factor in the endovascular treatment of distal anterior cerebral artery aneurysms. The contralateral transradial system is a useful treatment option for distal anterior cerebral artery aneurysms associated with sharp ipsilateral A1-A2 angles. However, if the distal anterior cerebral artery aneurysm cannot be clearly visualized through the contralateral system, an ipsilateral system will be required for contrast injection.

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.

Left Transradial Neurointerventions Using the 6-French Simmons Guiding Sheath: Initial Experiences with the Interchange Technique

BACKGROUND

The transradial approach using a Simmons-shaped catheter has been increasingly used for diagnostic cerebral angiography and neurointervention. In the transradial approach for neurointervention, the right radial artery is mainly used. However, in interventional cardiology, there are apparent clinical benefits with the left transradial approach for right-handed patients. To our knowledge, no studies have reported on neurointervention with the routine use of the left transradial approach. We therefore devised a novel technique for cases with an unachievable form of the Simmons shape using the standard technique, which we named the "interchange technique." The purpose of this study was to evaluate the technical feasibility of the left transradial neurointervention.

METHODS

This study is a retrospective review of our prospective database of consecutive patients who underwent a left transradial neurointervention, using a 6-French Simmons guiding sheath, performed from January through April 2021. The outcome variables studied were successful catheterization and procedure-related complications.

RESULTS

Twenty-one patients underwent a left transradial neurointervention including cerebral aneurysm coiling, carotid artery stenting, and meningioma embolization. The Simmons shape could not be formed with the standard technique for 3 patients, for whom we successfully formed the Simmons shape with our new interchange technique. The procedure was completely achieved in all 21 patients. No patients required crossover to the right radial or femoral arteries, and there were no radial artery spasms or occlusions or any procedural complications.

CONCLUSIONS

The left transradial approach for neurointervention is a technically feasible, safe, and effective alternative while providing more comfort to right-handed patients.

T-Configuration Stent Placement for Carotid Bifurcation Stenosis Co-Existing with Ipsilateral Intracranial Stenosis: A Case Report and Literature Review

In patients with carotid bifurcation stenosis co-existing with ipsilateral intracranial artery stenosis, combined treatment with carotid artery stenting (CAS)/carotid endarterectomy (CEA) and extracranial-to- intracranial (EC-IC) bypass can be a useful option to prevent future ischemic stroke events. EC-IC bypass requires a sufficient antegrade flow in the ipsilateral external carotid artery. However, standard CAS/CEA occasionally lead to external carotid artery occlusion. Herein, we present a case of successful one-stage endovascular revascularization of both the antegrade internal and external carotid artery flow using the carotid T-stent technique for carotid bifurcation stenosis co-existing with ipsilateral middle cerebral artery stenosis.

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.