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.

Treatment outcome of coil embolization for distal anterior cerebral artery aneurysms: A single-center experience.

OBJECTIVE: In recent years, endovascular treatment has become the treatment of choice for distal anterior cerebral artery (DACA) aneurysms. In this study, we report the outcomes of coil embolization for DACA aneurysms. METHODS: Eighteen DACA aneurysms in 16 patients treated with endovascular treatment between January 2010 and December 2020 were included in this study. We retrospectively analyzed patient characteristics, data on aneurysms, the reason for the selection of endovascular treatment, treatment technique, and treatment outcomes. RESULTS: There were 18 procedures in 16 patients. The average age was 65.7 years and 56% of patients were male. The average diameter of the dome was 5.5 mm, and the location of aneurysm was A3 in 83% and A4 in 17%. We mainly selected endovascular treatment for patients with a past history of craniotomy and head trauma, or with systemic comorbidities. The technical success rate was 94%, and adequate obliteration immediately after treatment was achieved in 72%. There were no symptomatic periprocedural complications. The retreatment rate was 11.1%. CONCLUSION: Coil embolization for DACA aneurysms yielded good treatment outcomes. Endovascular treatment for DACA aneurysms will become more common with advances in endovascular devices and the establishment of stable perioperative antiplatelet therapy.

Development of a recalcitrant, large clot burden, bifurcation occlusion model for mechanical thrombectomy.

OBJECTIVE Stroke is a major cause of disability and death in adults. Several large randomized clinical trials have shown the significant benefit of mechanical thrombectomy with modern stent retrievers in the treatment of large-vessel occlusions. However, large clots located at bifurcations remain challenging to treat. An in vivo model of these recalcitrant clots needs to be developed to test future generations of devices. METHODS Autologous blood was drawn from anesthetized swine via a femoral sheath. Blood was then mixed with thrombin, calcium chloride, and saline, and injected into silicone tubing to form cylindrical clots in the standard fashion. Matured clots were then delivered in an unfragmented fashion directly into the distal extracranial vasculature, at branch points where vessel sizes mimic the human middle cerebral artery, by using Penumbra aspiration tubing and the Penumbra ACE68 reperfusion catheter. RESULTS A total of 5 adult swine were used to develop the model. The techniques evolved during experiments in the first 3 animals, and the last 2 were used to establish the final model. In these 2 swine, a total of 8 autologous clots, 15-20 mm, were injected directly into 8 distal extracranial vessels at branch points to mimic a bifurcation occlusion in a human. All clots were delivered directly at a distal bifurcation or trifurcation in an unfragmented fashion to cause an occlusion. Ten revascularization attempts were made, and none of the branch-point occlusions were fully revascularized on the first attempt. CONCLUSIONS Using novel large-bore distal access catheters, large unfragmented clots can be delivered into distal extracranial vessels in a swine occlusion model. The model mimics the clinical situation of a recalcitrant bifurcation occlusion and will be valuable in the study of next-generation stroke devices and in training settings.

Transarterial Embolization of Type 2 Endoleak Post Thoracic Endovascular Aortic Repair (TEVAR) Using a Triaxial System With a 1.3-F Microcatheter: A Case Report.

Although transarterial embolization is recognized as a treatment for type 2 endoleaks, it can occasionally be challenging. We report the case of an 86-year-old man who presented with an enlarging thoracoabdominal aortic aneurysm following thoracic endovascular aortic repair. Using a triaxial system with a 1.3-F microcatheter, transarterial embolization of a type 2 endoleak was successfully performed through a long and tortuous arterial route comprising the thoracodorsal and ninth intercostal arteries. The postoperative clinical course was uneventful, and computed tomography obtained six days later showed no endoleak in the thoracoabdominal aortic aneurysm. This case suggests the usefulness of a triaxial system with a 1.3-F microcatheter for transarterial embolization of type 2 endoleaks.

Stent-retriever characteristics and strategies associated with recanalization in thrombectomy for acute ischemic stroke.

INTRODUCTION: Predictive factors for successful reperfusion in mechanical thrombectomy for acute ischemic stroke, and especially technical factors, remain controversial. We investigated various techniques for better angiographic outcomes. METHODS: In this retrospective study, acute ischemic stroke patients with large vessel occlusion treated with mechanical thrombectomy with combined technique were included. Scoring of the reperfusion grade for each attempt was conducted, and each attempt was divided into two groups based on successful reperfusion, which was defined using the presence or absence of modified thrombolysis in cerebral infarction 2b-3. The following characteristics were evaluated: the choice of stent-retriever, its length, occlusion site, thrombus position relative to deployed stent-retriever, methods of thrombectomy, and successful advancement of the distal access catheter to the proximal end of the thrombus. RESULTS: Among 251 patients who underwent mechanical thrombectomy, 154 patients (255 attempts: mTICI 0-2a group, n = 119; mTICI 2b-3 group, n = 136) were included in the analysis. The thrombus position relative to the deployed stent-retriever was likely associated with successful reperfusion, although it was not statistically significant (proximal two-thirds 56.8 %; distal one-third 44.3 %, p = 0.09). Successful advancement of the distal access catheter was related to successful reperfusion both in univariate analysis (success 57.9 %; fail 35.8 %, p < 0.01) and in multivariate regression analysis (odds ratio 2.45; 95 % confidence interval: 1.30-4.61, p < 0.01). CONCLUSIONS: Successful advancement of the distal access catheter to the proximal end of thrombus might be a key component for successful reperfusion in mechanical thrombectomy.

Intermediate catheter use is associated with intraprocedural rupture during coil embolization of ruptured intracranial aneurysms: a retrospective propensity score-matched study.

Introduction: An intermediate catheter (IMC) may pose a risk of intraprocedural rupture (IPR) during coil embolization of ruptured intracranial aneurysms (RIAs), because the pressure on the microcatheter and coil might be more direct. To verify this hypothesis, this study explored whether use of an IMC might correlate with an increased rate of IPR during coil embolization for RIAs. Methods: We retrospectively reviewed 195 consecutive aneurysms in 192 patients who underwent initial coil embolization for saccular RIAs at our institution between January 2007 and December 2023. Patients were divided into two groups with aneurysms treated either with an IMC (IMC group) or without an IMC (non-IMC group). To investigate whether IMC use increased the rate of IPR, a propensity score-matched analysis was employed to control for age, sex, maximal aneurysm size, neck size, bleb formation, aneurysm location, proximal vessel tortuosity, balloon-assisted coiling, type of microcatheter, and type of framing coil. Results: Ultimately, 43 (22%) coil embolization used IMC. In univariate analysis, the incidence of IPR was significantly higher in the IMC group compared with the non-IMC group (14.0 vs. 3.3%, p = 0.016). Propensity score matching was successful for pairs of 26 aneurysms in the IMC group and 52 aneurysms in the non-IMC group. The incidence of IPR was still significantly higher in the IMC group than in the non-IMC group (23.1 vs. 3.8%, p = 0.015). No significant differences in the incidences of ischemic complications and IMC-related parent artery dissection were observed between the two groups. Discussion: When using IMC for coil embolization of RIAs, the surgeons should be more careful and delicate in manipulating the microcatheter and inserting the coils to avoid IPR.

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.

Usefulness of Distal Access Catheter in Endovascular Embolization for Spinal Dural Arteriovenous Fistulae in the Mid-Thoracic Segment.

Objective: We report a case of mid-thoracic spinal dural arteriovenous fistula (SDAVF) that was successfully treated by transarterial embolization using a distal access catheter (DAC). Case Presentation: A 75-year-old male presented with about a 2-year history of slowly progressive bilateral lower extremity weakness and numbness. Spinal MRI revealed significant spinal cord lesions and flow voids below Th4. Spinal angiography revealed a mid-thoracic SDAVF. We performed a transarterial selective embolization using a 4.2Fr DAC combined with a 6Fr guiding catheter to obtain a stronger support. The fistula was completely occluded. Conclusion: For endovascular embolization of SDAVF, especially in the case of mid-thoracic SDAVF, using a DAC can be one of the most powerful options to obtain a stronger support.

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.

Novel triple coaxial system to navigate 9 French balloon guiding catheter into common carotid artery.

BACKGROUND: It is often hard to navigate a 9 French (F) balloon guiding catheter in patients with type III or bovine aortic arch. Also, a common carotid artery stenosis is challenging, because a guidewire cannot be advanced distally. We developed the combination of a 4F Simmons-type catheter and a 6F distal access catheter as a coaxial inner catheter to navigate a 9F balloon guiding catheter to overcome these difficulties. MATERIALS AND METHODS: Medical record at our institution was retrospectively reviewed and carotid artery stenting cases in which the 4F Simmons-6F distal access catheter system was employed as a coaxial catheter to navigate a 9F balloon guiding catheter were identified. To construct this system, a 4F 145 cm SY3 (Hanako Medical, Saitama, Japan) and a 6F 118 cm Cerulean DD6 (Medikit Co. Ltd., Tokyo, Japan) were usually employed. A rotating hemostatic valve should be as short as possible and was attached to only a 9F balloon guiding catheter. The length of a 0.035-in. guidewire needed to be 180 cm or longer. RESULTS: During the study period, 106 carotid artery stenting cases were identified. Of these, this system was employed in 29 cases that included 5 cases with a steno-occlusive lesion at common carotid artery/external carotid artery, 10 with type III or bovine arch, and 11 harboring both. In all the cases, a 9F balloon guiding catheter was successfully navigated. CONCLUSION: The 4F Simmons-6F distal access catheter system was useful in navigating a 9F balloon guiding catheter in patients with a common carotid artery stenosis, an external carotid artery occlusion, and an in-stent restenosis, especially when they also harbored type III or bovine aortic arch.

Usefulness of a distal access catheter in embolization of a short gastric artery pseudoaneurysm.

A 59-year-old man was admitted to our hospital for hematemesis. A hematoma was found in the posterior wall of the stomach, but the source of bleeding was not identified. One month later, contrast-enhanced computed tomography revealed a pseudoaneurysm in the short gastric artery. Embolization of the pseudoaneurysm was difficult due to vessel tortuosity. Usage of a distal access catheter improved catheter stability and enabled successful embolization. We consider a distal access catheter to be useful for embolization of an aneurysm beyond a tortuous artery.

Safety and efficacy of a new outreach distal access catheter, TACTICS, for coil embolization of unruptured intracranial aneurysms.

Background and purpose Current large-bore catheters can be easily and safely placed in the intracranial vessels for the stabilization of microcatheters in several neurointervention scenarios. We considered that a novel 3.4 French catheter (TACTICS, Technorat Corporation, Aichi, Japan) might be useful for intermediate/distal access in a triaxial system. Here, we present our initial experience using the TACTICS catheter for treatment of intracranial aneurysms. Materials and methods A total of 35 endovascular coils were placed to embolize unruptured intracranial aneurysms of the anterior circulation using the TACTICS catheter between December 2016 and November 2017. These procedures were retrospectively reviewed to assess aneurysmal obliteration (Raymond's classification), the volume embolization ratio (VER) and procedural complications in comparison with 96 conventional coil treatments during the 3-year period up to 2016. Data were matched for aneurysmal morphology (location, maximum diameter and aspect ratio) by the propensity method. Results In all procedures, the TACTICS catheter was atraumatically landed beyond the carotid siphon. There were no hemorrhagic or symptomatic ischemic complications. After propensity matching, 68 procedures were assessed (34 in each group). Achievement of Raymond's scale 1 (complete occlusion) showed the same frequency in both groups (50% vs. 50%, p = 0.23). The VER was significantly higher with the TACTICS catheter than with the conventional method (34.0% vs. 28.7%, p = 0.003). Conclusion We reviewed our initial experience of the TACTICS catheter. It can be used as an intermediate catheter for safe and effective endovascular coil embolization of anterior circulation aneurysms.

Optimal Guiding Catheter Length for Endovascular Coiling of Intracranial Aneurysms in Anterior Circulation in Era of Flourishing Distal Access System.

PURPOSE: To determine the minimum required guiding catheter length for embolization of various intracranial aneurysms in anterior circulation and to analyze the effect of various patient factors on the required catheter length and potential interaction with its stability. MATERIALS AND METHODS: From December 2016 to March 2017, 90 patients with 93 anterior circulation aneurysms were enrolled. Three types of guiding catheters (Envoy, Envoy DA, and Envoy DA XB; Codman Neurovascular, Raynham, MA, USA) were used. We measured the in-the-body length of the catheter and checked the catheter tip location in the carotid artery. We analyzed factors affecting the in-the-body length and stability of the guiding catheter system. RESULTS: The average (±standard deviation) in-the-body length of the catheter was 84.2±5.9 cm. The length was significantly longer in men (89.1±5.6 vs. 82.1±4.6 cm, P<0.001), patients older than 65 years (87.7±7.8 vs. 82.7±4.2 cm, P<0.001), patients with a more tortuous arch (arch type 2 and 3) (87.5±7.4 vs. 82.7±4.4 cm, P<0.001), and patients with a distal aneurysm location (distal group) (86.2±5.0 vs. 82.7±6.1 cm, P=0.004). A shift in the tip location was noted in 19 patients (20.4%); there was no significant different among the 3 catheters (P=0.942). CONCLUSION: The minimum required length of a guiding catheter was 84 cm on average for elective anterior-circulation aneurysm embolization. The length increased in men older than 65 years with a more tortuous arch. We could reach a higher position with distal access catheters with little difference in the stability once we reached the target location.

Forced Arterial Suction Thrombectomy Using Distal Access Catheter in Acute Ischemic Stroke.

Historical innovations in mechanical thrombectomy devices and strategies for ischemic stroke have resulted in improved angiographic outcomes and better clinical outcomes. Various devices have been used, but the two most common approaches are aspiration thrombectomy and stent-retrieval thrombectomy. Aspiration thrombectomy has advanced from the traditional Penumbra system to forced arterial suction thrombectomy and a direct aspiration first-pass technique. Newer generation aspiration catheters with flexible distal tips and a larger bore have demonstrated faster and better recanalization relative to older devices. Recently, several species of distal access catheters have similar structural characteristics to the Penumbra reperfusion catheter. Therefore, we used the distal access catheter for forced arterial suction thrombectomy in three patients with acute ischemic stroke. In each case, we achieved fast and complete recanalization without significant complications. Forced arterial suction thrombectomy using a distal access catheter might provide another option for mechanical thrombectomy in patients with acute ischemic stroke.

Utilization of a Novel, Multi-Durometer Intracranial Distal Access Catheter: Nuances and Experience in 110 Consecutive Cases of Aneurysm Flow Diversion.

BACKGROUND: Coaxial catheter support systems provide a safe and stable foundation in endovascular treatment of intracranial aneurysms. Increasingly, robust distal intracranial support is sought during complex neurointerventions. The AXS Catalyst 5 distal access catheter (Cat5) is a new intracranial catheter designed for improved trackability and stability. We report the first experience using Cat5 for aneurysm treatment by flow diversion. METHODS: A single-center aneurysm database was reviewed for cases of aneurysm treatment with the Pipeline embolization device (PED) that utilized Cat5. Data were collected for patient demographics, aneurysm characteristics, procedural details, catheter positions, vessel tortuosity, and catheter related complications. RESULTS: One hundred and ten cases of aneurysm flow diversion were successfully performed using Cat5. Patient age ranged from 21 to 86 years (mean 57 ± 12.5 years) with 84% women. Aneurysm size ranged from 2 to 28 mm (mean 5.7 ± 5.0 mm), with 97% in the anterior circulation. Twenty-four aneurysms (22%) were located beyond the ICA termination. Significant cervical carotid tortuosity was present in 26% of cases, and moderate to severe cavernous tortuosity (cavernous grade ≥2) in 45% of cases. Cat5 was tracked to the intended distal position in all cases with 100% technical success of PED implantation. No iatrogenic catheter-related vessel injury occurred, and major neurological morbidity occurred in 1 patient (1%). SUMMARY: The Cat5 is a novel, multi-durometer cranial distal access catheter designed for use in tri-axial systems. We have demonstrated the utility of Cat5 in 110 successful cases of flow diversion with a wide range of complexity. This catheter is a new tool in the neurointerventionalist's armamentarium to achieve robust and atraumatic distal access.

Direct carotid-cavernous fistulas occurring during neurointerventional procedures.

This study shows the frequency and types of carotid-cavernous fistula (CCF) complications that occurred during endovascular treatment. Transarterial endovascular surgeries involving the anterior circulation were performed for 1071 cases at our hospitals during four years. CCFs occurred in nine of 1071 cases (0.8%). CCF risk factors were female sex (p=0.032), aneurysmal location in the paraclinoid portion (p<0.001), and use of a distal access catheter (DAC) (p<0.001). There were no significant correlations between CCF risk and procedure type (p=0.411-1.0) and balloon use or nonuse (p=0.492). Eighty-nine percent (eight of nine) of the CCFs occurred at the genu of a cavernous internal carotid artery (ICA). Two cases of CCF disappeared spontaneously. The shunt was decreased by balloon expansion in one case, no additional treatment was required in one case, and five cases required transarterial fistula coil embolization. It is necessary to remember that a CCF may occur especially in aneurysmal treatment using a DAC in a female patient. The DAC and the 0.035-inch guidewire should be kept proximal to the carotid siphon and not go beyond it. When we cannot avoid navigating beyond it, we should consider using a softer DAC. In the case of a CCF caused by a DAC, it may be cured spontaneously or is treatable by transarterial coil embolization.