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.

Smaller diameter sheaths are required to safely perform transradial neurointerventions.

We read with great interest the paper titled "Transradial access with Simmons guiding catheter for carotid artery stenting: Feasibility and procedural complications in a single-center experience" by Muszynski et al. The authors concluded that a transradial carotid artery stenting (CAS) using a Glidesheath Slender 7F Introducer/7F Envoy Simmons 2 catheter system was feasible with a high procedural success rate and low access site complication rate. We completely agree with their conclusions. In this study, large-diameter sheaths were used. Large sheaths increase the risk of developing radial artery spasms. Interventionalists must be aware that radial artery spasm can not only require an access crossover, but can also cause severe access site complications, such as eversion or avulsion of the radial artery, catheter/sheath entrapment, and compartment syndrome. A 6F Simmons guiding sheath has a smaller outer diameter than the Glidesheath Slender 7F Introducer does, and it offers a large-bore working channel compatible with a 10-mm diameter Wallstent and Acculink. Transradial CAS with a 6F Simmons guiding sheath has previously yielded a high procedural success rate without serious access site complications. Nevertheless, we believe that a further decrease in the sheath diameter is required to safely perform transradial neurointerventions in more patients.

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.

Surgical Trapping of a Cavernous Carotid Aneurysm Causing Carotid Cavernous Fistula After Flow Diverter Placement: Technical Note and Literature Review.

BACKGROUND: Flow diverter (FD) treatment is a promising therapeutic strategy for intracranial aneurysms such as cavernous carotid aneurysms (CCAs). Direct cavernous carotid fistula (CCF) caused by delayed rupture of FD-treated CCAs has been reported, and endovascular therapy has been used in the literature. Surgical treatment is warranted for patients who have failed or are ineligible for endovascular treatment. However, no studies have evaluated surgical treatment to date. Here, this paper presents the first case of direct CCF due to delayed rupture of an FD-treated CCA managed with surgical internal carotid artery (ICA) trapping with bypass revascularization, in which the intracranial ICA with FD placement was successfully occluded with aneurysm clips. METHODS: A 63-year-old man with a diagnosis of large symptomatic left CCA underwent FD treatment. The FD was deployed from the supraclinoid segment of the ICA distal to the ophthalmic artery to the petrous segment of the ICA. Since angiography 7 months after the FD placement showed progressive direct CCF, left superficial temporal artery-middle cerebral artery bypass followed by ICA trapping was performed. RESULTS: The intracranial ICA proximal to the ophthalmic artery where the FD was placed was successfully occluded using two aneurysm clips. The postoperative course was uneventful. Follow-up angiography 8 months after the surgery confirmed complete obliteration of the direct CCF and CCA. CONCLUSIONS: The intracranial artery in which the FD was deployed was successfully occluded with two aneurysm clips. ICA trapping can be a feasible and useful therapeutic option to treat direct CCF caused by FD-treated CCAs.

Surgical revascularization for quasi-moyamoya disease associated with polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS) syndrome: a case report and literature review.

POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes) syndrome is a rare multisystem disease characterized by plasma cell dyscrasia and overproduction of vascular endothelial growth factor, which is related to disease activity. Recent treatment strategies have improved survival of patients suffering from this disorder; however, ischemic stroke remains a poor prognostic factor. POEMS patients with ischemic stroke frequently develop cerebral large artery stenosis/occlusion, followed by progressive stroke. Post literature review, we present an ischemic stroke case of quasi-moyamoya disease linked with this syndrome that was successfully treated with surgical revascularization. A 41-year-old woman diagnosed with POEMS syndrome developed progressive ischemic stroke due to quasi-moyamoya disease, despite decreased vascular endothelial growth factor level with lenalidomide and dexamethasone treatment. She underwent superficial temporal artery to middle cerebral artery bypass with encephalo-duro-myo-synangiosis bilaterally. The postoperative course was uneventful. Two years and five months after the stroke, neuroimaging demonstrated bypass patency, neovascularization after encephalo-duro-myo-synangiosis, and no recurrence of stroke. Our case is the first to report successful surgical revascularization for a POEMS patient. Surgical revascularization may be a useful treatment option for patients with quasi-moyamoya disease associated with POEMS syndrome, especially for those who develop refractory ischemic stroke despite reduced vascular endothelial growth factor level.

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.

Intraspinal canal platform system for coil embolization of anterior spinal artery aneurysm associated with spinal cord arteriovenous malformation: a case report and literature review.

BACKGROUND: The prognosis for spinal artery aneurysms associated with spinal cord arteriovenous malformations (AVMs) is poor because of the high rupture rate of aneurysms. However, endovascular treatment remains technically difficult because the catheter system must be constructed via the small-caliber anterior spinal artery (ASA) or posterior spinal artery (PSA), which feeds functionally eloquent spinal cord. A 2.6F Carnelian HF-S microcatheter (Tokai Medical Products, Aichi, Japan) has been specifically designed to assist a 1.6F Carnelian MARVEL S microcatheter (Tokai Medical Products) as a small-profile 'platform catheter' close to the target lesion. Here we present a prenidal ASA aneurysm treated using a 2.6F Carnelian HF-S microcatheter as an intraspinal canal platform catheter and review related literature. CASE PRESENTATION: A 50-year-old man presented with a subarachnoid haemorrhage due to cervical spinal cord AVM. Diagnostic vertebral angiography revealed the AVM supplied by the PSA originated from the right C2 segmental artery and ASA arising from the right V4 segment. Superselective angiography for each feeder was achieved through a 2.6F Carnelian HF-S microcatheter, and a prenidal ASA aneurysm was diagnosed, which was clinically consistent with haemorrhagic origin. A 1.6F Carnelian MARVEL S microcatheter was cannulated into the aneurysm through the 2.6F Carnelian HF-S microcatheter positioned at the ASA. The aneurysm coiling was successfully performed without system instability or periprocedural complications. CONCLUSIONS: Only a few cases have described endovascular treatment for spinal artery aneurysms. To date, no reports have been published regarding the use of an intraspinal canal platform catheter to treat spinal artery aneurysms. A 2.6F Carnelian HF-S microcatheter served as a useful intraspinal canal platform catheter for coil embolization of the ASA aneurysm. This system can provide excellent accessibility and controllability for endovascular treatment of spinal artery lesions.

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.

New Distal Balloon Protection System for Transradial Carotid Artery Stenting After Percusurge Guardwire Withdrawal: Jailbreak Technique.

BACKGROUND: Embolic protection devices are commonly used to prevent cerebral embolism during carotid artery stenting (CAS). However, the PercuSurge Guardwire device, a distal balloon protection device, was discontinued in April 2021. We present a case of successful CAS using a new distal balloon protection system. The procedure, referred to as the jailbreak technique, was performed via transradial access. METHODS: A 67-year-old man underwent CAS, using the jailbreak technique, for right carotid stenosis with a vulnerable plaque. 6-French (Fr) and 4-Fr Simmons guiding sheaths were delivered into the right common carotid artery via the right and left transradial access, respectively. Distal balloon protection was provided using a 2.6-Fr dual-lumen balloon microcatheter (Pinnacle Blue 20, Tokai Medical Products, Aichi, Japan) via the 4-Fr Simmons guiding sheath. A 4.2-Fr catheter was coaxially delivered proximal to the balloon and distal to the lesion. RESULTS: After CAS was successfully performed via the 6-Fr Simmons guiding sheath, the Pinnacle Blue 20 was retrieved through the 4.2-Fr catheter without interfering with the distal stent flare and stent struts. Postprocedural neuroimaging revealed no evidence of ischemic stroke. CONCLUSIONS: The jailbreak technique allows distal balloon protection during transradial CAS. This is a useful treatment option for patients with carotid stenosis.

The Current Status in Intraoperative Image-Guided Neurosurgery Associated with Progressive Operating Rooms: A Retrospective Analysis.

OBJECTIVE: Shinshu University Hospital has advanced operating rooms including a mobile computed tomography (mCT) room, Smart Cyber Operating Theater (SCOT) with intraoperative magnetic resonance imaging, hybrid operating room (hOR) with intraoperative image-guided surgery, and conventional operating rooms. We investigated the characteristics of cases assigned to each operating room. METHODS: Five hundred forty neurosurgery cases from January 2018 to April 2021 were analyzed. We analyzed the selection of operating room according to pathology, surgical device requirement, and urgency, and we examined associations between operating room characteristics and these factors. RESULTS: Neurological surgeries were performed in an mCT room, an hOR, a SCOT, and a conventional operating room in 333 (61.7%), 64 (11.9%), 49 (9.1%), and 94 (17.4%) cases, respectively. mCT rooms were more frequently selected than other rooms for vascular/extra-axial tumors, which have a lower need for intraoperative image guidance. Spinal surgeries with segment diagnosis or intraoperative bone removal tended to be performed in the hOR. The rate of SCOT use tended to be higher for intra-axial tumors with poorly circumscribed borders than for vascular/extra-axial tumors. Endoscopic procedures were more frequently performed in the SCOT and mCT rooms than in hORs and conventional operating rooms. Emergency surgeries were often performed in the conventional operating rooms, even in cases where SCOT and hOR seemed suitable. CONCLUSIONS: Intraoperative image-guided surgeries were performed according to the characteristics of each operating room best suited for various diseases and operative methods. Further research is needed to prove whether operating room selection improves neurosurgical outcomes.

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.