A Novel Training Method for Endovascular Clot Retrieval Using a Portable Vascular Model and Red Film.

Hands-on training is a crucial part of education in neuroendovascular treatment to ensure safe and rapid acquisition of techniques. However, there is a significant gap between training and actual clinical practice. This study will introduce innovations for more practical thrombus retrieval training that was developed in this process. A Smart Vascular Model 3 in 1 was used. A pink pseudothrombus was inserted into the M1 (horizontal segment of the middle cerebral artery) section of the model. Then, a "red underlay" purchased at a stationery store was placed to cover the proximal part of M1 and beyond so that the pseudothrombus was not visible. The thrombus was retrieved during training by looking for the location of the thrombus based on the behavior and resistance of the tip of the guidewire and deployment of the stent retriever. The participants were required to have detailed observation skills and precise manipulation skills using a red film to prevent the direct visualization of the pseudothrombus. The implementation of this innovation to the previous hands-on training made the training more practical and effective. If the exact thrombus location can be determined by the behavior of the wire tip, the device's capabilities can be maximized, and rapid retrieval can be expected. It could also reduce complications, as unnecessary peripheral guidance of the device could be avoided.

Passive Approximator Vascular Closure Device Use in Patients with Shallow Femoral Artery Depth Increases Puncture-site Complications in Neuroendovascular Treatment.

OBJECTIVE: Puncture-site complications in interventional radiology sometimes cause severe conditions. Vascular closure devices play an important role in preventing puncture-site complications. Vascular closure devices are divided into 2 types, the directly suturing or clipping type (active approximators) and adherent sealant types (passive approximators). However, which types of vascular closure device are the safest and most effective for achieving hemostasis remains unclear. We analyzed the efficacy of each type of vascular closure device and risk factors for puncture-site complications. METHODS: This study investigated 327 consecutive cases of neuroendovascular surgery using a transfemoral procedure during a 2-year study period. Passive approximators (Angioseal [St Jude Medical, Saint Paul, MN] and Exoseal [Cordis Corporation, Miami, FL]) were mainly used in the first half and active approximators (Perclose [Abbot Vascular, Santa Clara, CA]) in the second. We compared groups and estimated risk factors for puncture-site complications. RESULTS: All procedures were successful. Comparing groups with and without puncture-site complications, use of passive approximators and ≥3 antithrombotic medications tended to be more frequent and distance from skin to femoral artery and body mass index tended to be lower in the group with complications without significance. The cutoff for femoral artery depth calculated from a receiver operating characteristic curve was 16.43 mm. Multivariate analysis revealed ≥3 antithrombotic medications (P = 0.002, OR 15.29, 95% CI 2.76-85.76) and passive approximator use in patients with femoral artery depth <16.43 mm (P < 0.001, OR 17.08, 95% CI 2.95-57.80) were significantly higher in the group with puncture-site complications. CONCLUSIONS: Passive approximator use in patients with shallow femoral artery depth increases puncture-site complications in neuroendovascular treatment.

Relationship between Shape Retention and X-ray Absorption Value of the Tip of Microcatheters in Neuroendovascular Treatment.

Objective We noticed that the X-ray absorption value of the tip of each microcatheter used for aneurysm treatment varied from product to product. We hypothesized that the differences were caused by variations in the metal's density braid, which could be related to the ability of the tip to retain its shape. Methods The X-ray absorption value of each microcatheter tip was measured. Next, heat forming was performed using a shaping mandrel at 6 mm and 90 degrees to determine whether there was a correlation between the X-ray absorption value and the forming angle. Next, the optimal mandrel angle for forming each microcatheter at 90 degrees was investigated. We also examined the shape retention after 20 times wire insertions into each microcatheter. Conclusion It was found that the higher the X-ray absorption value, the harder it was for the microcatheter to be formed. The mandrel angle required to form 90 degrees was determined by the X-ray absorption value. The higher the X-ray absorption value, the higher the shape retention of the tip shape. The heat formation and shape-retention conditions of the microcatheter tip were correlated with the X-ray absorption value of the metal braid. Even for unknown microcatheters, the optimum shaping conditions can be inferred from the X-ray absorption value.

A novel remote hands-on training for neuroendovascular-based treatment in the era of the COVID-19 pandemic.

The COVID-19 pandemic has demanded a change in learning modalities, which led us to develop a remote personal training system for clinicians performing neuroendovascular procedures. A portable vascular model designed for practicing catheter navigation guidance, thrombus retrieval, and intracranial aneurysm coil embolisation was established. We created an environment that enabled interactive dialogue and communication across long distances using the Internet. The instructor conducted approximately 2 h of hands-on training with two to four trainees at a time. Despite the restrictions enforced by the Government of Japan due to the COVID-19 pandemic, 17 online hands-on training were successfully conducted throughout Japan over 1 year for a total of 48 trainees. The developed remote training programme, to avoid the aggregation of a large number of trainees at a developed time, proved to be at par with the conventional learning system. The training was well-received since the operation time was longer and the question and answer sessions were more fulfilling compared to the conventional format in which a group of trainees had got a brief opportunity to receive actual hands-on experience.

A Novel Approach to Neuroendovascular Treatment Looking Up from the Ascending Aorta Using an Alpha Shape Guiding Catheter.

BACKGROUND: A method of guiding an intermediate catheter from a new alpha-type guiding catheter placed in the ascending aorta to the carotid artery is evaluated in neuroendovascular treatment in challenging anatomic directions of the guiding catheter, such as the bovine aortic arch and type III aortic arch. METHODS: The existing 8-Fr guiding catheter was given a strong bending shape at the tip to make it an alpha type. The total length of the catheter was 85 cm. This guiding catheter was inserted into the ascending aorta to verify whether a 6-Fr intermediate or aspiration catheter could be coaxially guided into the right and left internal carotid arteries. A silicone vascular model was used for evaluation and in actual clinical cases. RESULTS: Creating an alpha shape of the catheter at the aortic arch was very easy. The inner catheter could be easily guided from the brachiocephalic artery to the right common carotid artery by pushing the alpha shape guiding catheter toward the aortic valve. The catheter was easily guided into the left common carotid artery when the α-guide was pulled a little bit backward. The 0.071-inch lumen aspiration catheter reached the bilateral middle cerebral arteries. CONCLUSIONS: The 8-Fr alpha shape guiding catheter quickly guides the inner catheter into the bovine and the type III aortic arch by looking up from the ascending aorta.

Positional Relationship between Two Microcatheters according to the Navigation Sequence within the Curved Vessel in Neuroendovascular Procedures.

In neuroendovascular treatment, there are many opportunities to guide multiple catheters into the intracranial blood vessels. We report the relationship between two microcatheters according to the guiding order with experimental in vitro studies. We hypothesize that in a bent blood vessel such as a paraclinoid region of the internal carotid artery, the catheter that was first guided tended to pass through the inside, and the catheter that was guided later tended to pass through the outside. The in vitro verification was performed using a microcatheter and a balloon catheter in a silicone vascular aneurysmal model. As a result, it was found that the two catheters were arranged according to our hypothesis. This finding was also observed during the actual operation of balloon-assisted coil embolization. The positional relationship between the two catheters according to the navigation order is very important, in particular during balloon-assisted coiling and stent-assisted coiling via a jailed microcatheter.

Distal radial artery approach is safe and effective for cerebral angiography and neuroendovascular treatment: A single-center experience with ultrasonographic measurement.

BACKGROUND: The transradial artery approach to cerebral angiography can reduce both patient stress following examination and the risk of major complications due to hematoma. Recently, the distal radial artery approach (DRA) has garnered attention in cardiology as a minimally invasive method. DRA is also considered applicable to neurosurgery, although concerns about procedural difficulty and complications persist. Therefore, this study aimed to evaluate the efficacy of the DRA in cerebral angiography and neuroendovascular treatment. METHODS: We retrospectively selected 30 consecutive patients for whom the DRA was attempted for cerebral angiography at our hospital. The patients' age, sex, height, weight, and medical history information was collected and correlated with successful puncture and complications. The diameter of the distal radial artery (RA) was measured using ultrasonography. RESULTS: The median patient age was 67 years (range, 32-87 years) and 21 (70%) were men. The median diameter of the distal RA was 2.3 mm (range, 1.7-3.2 mm). Distal RA puncture was successful in 23 patients (77%) and no complications were noted; however there was no significant correlation between successful puncture and any of the patient factors. Carotid artery stenting and preoperative tumor embolization were performed via DRA in six and three cases, respectively. Although puncture site hematoma occurred in only one case, all treatments were successful, and no major complications were observed. CONCLUSION: DRA can be safely used for cerebral angiography and neuroendovascular treatment.

Direct carotid puncture for endovascular surgery of intracranial aneurysms: Technical note for avoiding complications.

BACKGROUND: While the most intracranial aneurysms are approachable by femoral or brachial artery puncture during endovascular surgery, in some cases, the lesion is difficult to reach due to complications such as the presence of winding pathways. Direct carotid puncture (DCP) is an alternative access approach, despite the potential risk of fatal neck hematoma. Herein, we describe the DCP technique in a series of five patients with intracranial aneurysms, together with its technical considerations. METHODS: Patients with intracranial aneurysms who underwent endovascular surgery using DCP were reviewed retrospectively. We selected the 3F to 6F systems for DCP depending on the necessity of adjunctive techniques. To prevent DCP-associated complications, we (1) conducted a micropuncture before introducing the short sheaths,(2) selected the smallest possible size for the system, (3) reversed heparin postoperatively, and (4) performed perioperative intubation/sedation management. RESULTS: Five out of 535 patients underwent DCP in our hospital between 2015 and 2019; successful vascular access was achieved in all cases. Although a minor neck hematoma occurred in one case, the patient did not require additional treatment. According to a literature review, severe neck hematoma requiring rescue therapy occurs in 5 out of 95 cases (5.3%). CONCLUSION: Although the potential risk of neck hematoma is not negligible, the DCP technique appears to be a safe and effective approach in treating intracranial aneurysms with challenging access routes in cases where perioperative counter measurements are appropriately performed.

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.

BACKGROUND: The benefits of the right transradial approach for anterior circulation lesions using a 6F Simmonds guiding sheath have been reported. However, this technique can be anatomically challenging in the type I aortic arch. Furthermore, to the best of our knowledge, no studies have reported on neurointervention using a Simmonds guiding sheath and the left transradial approach. We devised a novel technique using the contralateral subclavian artery as an "anchor" to reform the Simmonds curve, named the subclavian artery anchoring technique (SCAT). The purpose of the present study was to evaluate the feasibility, safety, and usefulness of neurointervention with the SCAT for patients with a type I aortic arch treated with the right transradial approach and patients treated with the left transradial approach. METHODS: Ten consecutive patients treated from June 2018 to January 2019 were included in the present study. We retrospectively analyzed: 1) the success rate for reforming the Simmonds curve using the SCAT; 2) the success rate for introducing the 6F Simmonds guiding sheath into the target common carotid artery; 3) the success rate for completing the procedure; 4) periprocedural complications; and 5) vascular access site complications. RESULTS: In all 10 patients, the Simmonds curve was reformed, and a 6F Simmonds guiding sheath was introduced into the target common carotid artery. The procedure was successfully achieved for all 10 patients without periprocedural or vascular access site complications. CONCLUSIONS: The results of the present study have shown that this technique is a feasible, safe, and useful method for patients with type I aortic arch treated with a right transradial approach or a left transradial approach. SCAT makes up for a deficiency in the transradial approach with a 6F Simmonds guiding sheath.

Surgical Rescue Retrieval of a Filter Protection Device in Carotid Artery Stenting with Stent Deformation: Case Report and Literature Review.

BACKGROUND: Despite the development of neuroendovascular treatment, device-related complications requiring surgical procedures remain. We report a case requiring surgical retrieval of a filter protection device in carotid artery stenting (CAS) with an open-cell stent, due to stent deformation, and review past reports on CAS in which surgical retrieval of devices was required. CASE DESCRIPTION: An 82-year-old man underwent CAS for symptomatic right internal carotid artery stenosis with severe calcification and tortuosity. Immediately after placement of the open-cell stent, stent deformation was detected and the filter protection device could not be retrieved. All noninvasive device retrieval attempts failed, and the device was ultimately retrieved surgically. After surgery, right cerebral infarction progressed increased, but no permanent deficit was observed. CONCLUSIONS: As the treatment of cerebrovascular disease shifts from surgical to endovascular approaches, surgeons must be familiar with devices and techniques to manage complications of neuroendovascular treatment.

Wake-up (or wake-up for) stroke: a treatable stroke.

A 74-year-old man was admitted to the Emergency Room of our institution with worsening dysarthria, left-side weakness and hypoesthesia (NIHSS score: 5) since his awakening at 7:30 a.m. The evening before, he had gone to sleep at 10:30 p.m. Brain computed tomography (CT) and cervicocranial CT angiography showed low density attenuation of the right caudate nucleus head and lenticular nucleus and sub-total occlusion of ipsilateral middle cerebral artery (MCA) pre-bi/trifurcation M1 segment. Brain CT perfusion showed an ischemic core in the right striatal region, surrounded by a wide region of ischemic penumbra. Although the onset of symptoms, defined as "time last-seen well", was 14 hours before presentation, the following worsening of neurological conditions (NIHSS score: 12) and the evidence of cerebral blood flow / cerebral blood volume mismatch at CT perfusion led us to propose neuroendovascular treatment on the basis of an off-label use. Neuroendovascular treatment by Penumbra system was achieved and the right MCA was only partially recanalized. The patient was discharged with NIHSS score of 12. At six months, modified Rankin scale score was 3. To the best of our knowledge, this is the first Italian case report describing a patient who underwent successful neuroendovascular treatment for a "wake-up stroke" without clinical worsening nor major complications and an acceptable clinical outcome. This was possible thanks to an extension of the therapeutic window guided by CT perfusion.