Prediction of obliteration of unruptured cerebral aneurysm by residual aneurysm volume after flow diverter stent treatment.

Introduction There is no methodology to predict aneurysm occlusion using residual volume after flow diverter stent treatment. We retrospectively examined whether residual aneurysm volume at 6 months postoperatively can predict the degree of aneurysm obliteration at 1 year after flow diverter stent treatment. Materials and Methods This single institution study included 101 consecutive patients who underwent flow diverter stent treatment for unruptured cerebral aneurysm. Based on pre-treatment aneurysm volume, the percentage residual volume was calculated 6 months postoperatively. The volume of the aneurysm was determined using the volume calculation function of the cerebral angiography equipment. 1 year postoperatively, patients were classified into two groups: the good obliteration group (GG; O'KellyMarotta [OKM] grading scale: C and D) and the poor obliteration group (PG; OKM: A and B). Statistical analysis was performed to determine if there was a difference in residual aneurysm volume percentage at 6 months postoperatively between the two groups. Results A total of 20 patients were studied: 6 in the GG and 14 in the PG. Mean residual aneurysm volume at 6 months postoperatively in the GG was 33.1% (±34.7), while that in the PG was 80.6% (±24.8) (P=0.018). A residual aneurysm volume of ≥35.2% at 6 months postoperatively was significantly associated with poor aneurysm obliteration at 1 year postoperatively (AUC=0.88, P=0.008). Conclusions Residual aneurysm volume percentage at 6 months after flow diverter stent treatment might be able to predict the likelihood of aneurysm occlusion at 1 year postoperatively.

The case of treatment for carotid web - Double-layer micromesh stent implantation in our hospital.

Background: A carotid web is a shelf-like structure on the posterior wall of the origin of the internal carotid artery, and it is believed to cause cerebral infarction due to thrombus formed by turbulent flow with stagnation of blood flow. Recently, it has been suggested that recurrent cerebral infarction cannot be prevented in patients with a symptomatic carotid web by conventional medical management alone. However, there is still no consensus on the treatment of carotid webs. Carotid artery stenting (CAS) with the CASPER stent (Microvention, Terumo, Tustin, CA, USA) was performed in six consecutive patients with symptomatic carotid webs, and the results are reported along with a review of the literature. Methods: Six consecutive patients with a diagnosis of internal carotid artery stenosis due to a carotid web on magnetic resonance imaging and digital subtraction angiography (DSA) were included in this study. All patients underwent dual antiplatelet therapy approximately 10 days before surgery and after 6 months, and then, a CASPER stent was implanted under general anesthesia. All patients were evaluated postoperatively by DSA 6 months after treatment. Results: In all patients, no in-stent stenosis was seen 6 months after the operation, and no symptomatic cerebral infarction occurred within 1 year after the procedure. Conclusions: CASPER stent implantation may be effective for treating carotid webs.

Strategy of cerebral endovascular treatment for cervical internal carotid artery stenosis with a persistent primitive hypoglossal artery.

Background: Persistent primitive hypoglossal artery (PPHA) is a rare residual arterial anastomosis. We placed a CASPER stent using Spider FX as an embolic protection device (EPD) in a patient with internal carotid artery (ICA) stenosis and PPHA. There are no reports of carotid artery stenting (CAS) using a CASPER stent for ICA stenosis with PPHA. We report the EPD strategy used in this case and the usefulness and precautions of CASPER stent insertion for cervical ICA stenosis in association with PPHA. Methods: A 9Fr sheath was placed in the right femoral artery and a 9Fr Branchor balloon guide catheter was guided to the common carotid artery. A Spider FX was placed proximal to the bifurcation of the ICA and the PPHA. A 10 mm × 20 mm CASPER stent was deployed at the site of the stricture with no postoperative ischemic complications. Results: There was no intra-stent occlusion, stenosis, or plaque protrusion immediately after surgery, and no postoperative ischemic complications were observed. Conclusion: CASPER stent deployment with the Spider FX in the ICA and PPHA bifurcation can be considered to be an effective treatment method for ICA stenosis associated with PPHA. However, care should be taken in selecting the appropriate EPDs and stents depending on the location of the stenosis and bifurcation of the PPHA.

Treatment strategy for giant thrombosed aneurysm of the basilar artery with associated obstructive hydrocephalus.

Background: There is no established adequate treatment for thrombosed aneurysm of the basilar artery with obstructive hydrocephalus. We conducted coil embolization and peritoneal shunting followed by placement of a stent expected to exert flow diversion (FD) effects to treat 2 patients with giant thrombosed aneurysms of the basilar artery with associated obstructive hydrocephalus, with good results. Methods: From April 2019 to March 2021, consecutive two cases of symptomatic hydrocephalus due to giant thrombosed aneurysms in the posterior cranial fossa at our hospital were treated. At first, coil embolization was performed to prevent aneurysm rupture. After coil embolization, ventriculoperitoneal shunting was performed. Finally, stent-assisted coil embolization was performed with flow re-direction endoluminal device (FRED) or low-profile visualized intraluminal support device (LVIS) stent. Results: Both patients were discharged after recovering well, with no postoperative hemorrhagic or ischemic complications. Conclusion: Staged surgery using a FRED for flow diverter or an LVIS stent expected to have FD effects may offer an effective treatment option.

Usefulness of the Three-step Simple Binostril Approach in Endoscopic Endonasal Transsphenoidal Surgery.

We describe a three-step, simple binostril approach to endoscopic endonasal transsphenoidal surgery in cases of sellar/parasellar lesions. In the first step, the mucosa of the lower third of the ethmoid bulla on the outside was coagulated with monopolar microdissection needle and opened to create space on the outside of the middle turbinate. The middle turbinate was moved outward using this space, and the natural ostium of the sphenoid sinus could be confirmed easily. In the second step, a less than 10 mm incision was made from the right natural ostium of the sphenoid sinus to the right nasal septal mucosa. The anterior wall of the sphenoid sinus was removed to free the sphenoid sinus. In the third step, the instrument was inserted through the left nostril using a hole connected to the natural ostium of the sphenoid sinus to reach the sellar floor via both nostrils. It took longer for the trainee than for the instructor to reach the sellar floor in the first four cases. However, there was no significant difference in the approach time after the fifth case. Approach-related postoperative complications were observed in 52 cases of sellar/parasellar lesions performed. This approach was considered to provide sufficient space and was simple and less burdensome to the patient.

Usefulness and problems of Y-Stent and T-Stent assisted coiling for unruptured cerebral aneurysms.

INTRODUCTION: We are going to discuss about usefulness and problems of Y-stent and T-stent assisted coiling for unruptured cerebral aneurysms. METHODS: A retrospective review was performed to identify patients who were treated using Y-stent or T-stent assisted coiling (Y-SAC, T-SAC) for 25 unruptured cerebral aneurysms from April 2017 to September 2021. Fifteen cases were treated using Y-SAC, 10 were done using T-SAC. Only a case was treated with Low-profile Visualized Intraluminal Support (LVIS; MicroVention TRUMO, Aliso Viejo, California, USA) and Neuroform ATLAS (Striker, Kalamazoo, Michigan, USA), Others were done with two Neuroform ATLAS stents. RESULTS: Y-SAC and T-SAC were succeeded in all cases. In two cases that were treated using Y-SAC, ischemic complications were observed. A patient received additional embolization because subarachnoid hemorrhage (SAH) was appeared after discharge. On follow-up imaging, complete occlusion (CO) was confirmed in all cases. CONCLUSION: The position of deployment of stents was the most important issue. In particular, the second stent should be deployed as to contact the first stent, as possible. The case that the position of the second stent was shifted, and neck was not covered was observed. In the cases that are treated by using T-SAC, microcatheter must be navigated to distal position as possible. In that point, Y-SAC is more applicable. The familiarization of Y-SAC or T-SAC will expand the indication of endovascular treatment for unruptured cerebral aneurysms.

Successful use of an LVIS device to treat unruptured distal aneurysm of the superior cerebellar artery at a vascular bifurcation.

Background: Aneurysms of the distal superior cerebellar artery (SCA) account for only a small proportion of all cerebral aneurysms. Reports of the use of flow diverters (FDs) started to appear in 2013. We obtained good results from placement of a low-profile visualized intraluminal support device (LVIS) to treat unruptured distal aneurysm of the SCA at a vascular bifurcation. Case Description: A 65-year-old man presented at our hospital with sudden peripheral facial nerve palsy and suspected subarachnoid hemorrhage. Investigational cerebral angiography revealed an aneurysm at the bifurcation of the caudal and rostral trunks of the SCA. An LVIS was placed with the aim of obtaining flow diversion, and cerebral angiography 6 months after this procedure showed disappearance of aneurysm with preservation of the distal SCA. Conclusion: Twelve cases of the use of FDs to treat aneurysms of the SCA have been reported previously. However, none of those reports described FD use to treat an aneurysm at a vascular bifurcation, as in the present case. Our results suggested that LVIS placement with the aim of obtaining flow diversion may be useful for the treatment of aneurysms at such sites.

Usefulness of endoscope-assisted surgery under exoscopic view in skull base surgery: A technical note.

BACKGROUND: The use of the exoscope has been increasing in the field of neurosurgery, as it can set the visual axis freely, enabling the surgeon to operate in a comfortable posture. Although endoscope-assisted surgery for compensation of insufficient surgical field is useful under the microscope, we report that using an endoscope in exoscopic surgery is safer and more useful. METHODS: The exoscope used was ORBEYE. All surgical procedures were performed exoscopically from the beginning of the surgery. When endoscopic observation was required during the operation, the endoscope was inserted under observation by an exoscope. The exoscopic screen was 4K-3D and endoscopic screen was 4K-2D, the operation was performed while observing both screens at the same time. The endoscope was held manually or by a mechanical holder. RESULTS: Twenty-two cases, including 14 requiring microvascular decompression (MVD) and eight requiring tumor removal, were performed by endoscopic-assisted exoscopic surgery. The endoscope could be inserted safely because its relationship with the surrounding structure could be observed under the exoscope, and the operator could observe both screens without moving the head. Fourteen of 22 patients required additional endoscopic treatment. Satisfactory two-handed operation was performed in 13 cases. Symptomatology disappeared in all cases of MVD, and sufficient tumor resection was achieved. CONCLUSION: Exoscopic surgery provides excellent surgical view that is not inferior to conventional microsurgery. As a large space can be secured between the scope and the surgical field, it is safer and easier to manipulate the endoscope under the exoscope.

Iatrogenic Middle Meningeal Arteriovenous Fistula During Embolization: Two Case Reports and Literature Review.

Objective Dural arteriovenous fistulae of the middle meningeal artery are rare. There are few reports of complications associated with endovascular therapy. This report describes two cases of iatrogenic middle meningeal arteriovenous fistula due to vascular injury sustained during endovascular treatment. Case description Case 1 was that of a 46-year-old woman. She was treated for an incidentally discovered dural arteriovenous fistula of the cerebellar tentorium by transarterial embolization. During the procedure, a middle meningeal arteriovenous fistula occurred because of vessel laceration by the forced advancement of the distal access catheter (DAC). After the intervention, she developed tinnitus. Follow-up angiography revealed a middle meningeal arteriovenous fistula. The fistula was treated by coil embolization of the affected middle meningeal artery. The second case was that of a 56-year-old woman who developed a middle meningeal arteriovenous fistula from the perforation caused by the microguidewire during tumor embolization. The fistula was treated by occluding the proximal segment of the affected artery with coils. Both patients were discharged without neurological complications after the endovascular procedures. Conclusion Endovascular surgeons should be aware of the possibility of middle meningeal arteriovenous fistula as a potential complication of endovascular procedures.

Distal Embolic Protection by Manual Compression of the Vertebral Artery in Subclavian Artery Stenting.

Objective: There is no established method for preventing vertebral artery embolization in percutaneous transluminal angioplasty (PTA) for subclavian artery stenosis. We manually compressed the supraclavicular fossa outside the sternocleidomastoid muscle to disrupt vertebral artery blood flow and prevent embolism. We report the usefulness of this procedure. Case Presentations: Between April 2017 and July 2018, three patients with severe stenosis of the subclavian artery of 80% or higher were examined. For these patients, subclavian artery stenting was performed. The approach was via the left brachial artery in one patient and right femoral artery in two patients. After crossing the lesion, the vertebral artery was manually compressed and angiography confirmed that blood flow was blocked. In all patients, stent placement was successfully performed and good dilatation was confirmed by angiography. There were no neurological complications and no findings suggestive of acute cerebral infarction were found on magnetic resonance imaging (MRI). Conclusion: Prevention of distal embolism by manual compression is simple, does not require multiple catheters, and is useful for subclavian artery stenting.

Evaluation of the Partial Re-Sheathing Technique with the Solitaire Stent Retrieval System In Vitro Model and a Representative Case.

Objective: Vascular injuries are severe complications associated with endovascular thrombectomy. In the present study, we evaluated the re-sheathing technique with the Solitaire stent retrieval system to overcome these complications. Methods: We examined the diameter and resistance to retrieval of the Solitaire FR device (6 × 20 mm) during full and partial deployment in vitro model. We also examined a representative case in which the re-sheathing technique was used. Results: We found that the Solitaire device spread elliptically during partial deployment. As the length of the partially deployed device decreased, the maximum diameter also decreased. The distal half of the stent retained 80% of the maximum diameter of the partially deployed Solitaire. The resistance to retrieval was significantly higher during full deployment (mean ± standard deviation; 0.32 ± 0.04 kg) than during half deployment (0.22 ± 0.04 kg) (Mann-Whitney U test; p = 0.006). The re-sheathing technique was used in the representative case due to the high resistance to retrieval, which enabled recanalization without extravasation. Conclusion: In cases of high resistance to retrieval, minimal re-sheathing may be useful for capturing the thrombus without increasing the risk of vascular injury.

Treatment outcomes of carotid artery stenting with two types of distal protection filter device.

PURPOSE: Preventing cerebral embolism from debris produced during carotid artery stenting (CAS) is important. This study compared the treatment outcomes of CAS using two types of filter-based embolic protection devices currently in use in Japan. MATERIALS AND METHODS: We assessed 121 consecutive cases of CAS performed with FilterWire EZ™ between July 2010 and November 2012 and 37 consecutive cases of CAS performed with the Spider FX™ between November 2012 and June 2013. A Carotid Wallstent™ was used in all cases. The incidence of positive lesions on diffusion-weighted magnetic resonance imaging (DWI) and stroke were compared between the groups. RESULTS: Postoperative DWI-positive lesions were observed in 38 (31.4%) and 14 (37.8%) patients in the FilterWire and Spider groups, respectively. In the FilterWire group, complications were transient ischemic attacks in 3 (2.5%) patients, cerebral infarction in 2 (1.7%) patients (1 patient each with minor and major stroke), and cerebral hemorrhage due to hyperperfusion syndrome in 1 (0.8%) patient. In the Spider group, except for cerebral infarction (minor stroke) in 1 (2.7%) patient, no complications were observed. No significant differences were observed in the incidence of complications between the groups. CONCLUSION: FilterWire EZ and Spider FX are comparable in terms of treatment outcome.

Distal protection filter device efficacy with carotid artery stenting: comparison between a distal protection filter and a distal protection balloon.

PURPOSE: This retrospective study aimed to compare the effectiveness of the embolization prevention mechanism of two types of embolic protection device (EPD)-a distal protection balloon (DPB) and a distal protection filter (DPF). METHODS: Subjects were 164 patients scheduled to undergo carotid artery stenting: a DPB was used in 82 cases (DPB group) from April 2007 until June 2010, and a DPF was used in 82 cases (DPF group) from July 2010 to July 2011. Rates of positive findings on postoperative diffusion-weighted imaging (DWI) and stroke incidence were compared. RESULTS: Positive postoperative DWI results were found in 34 cases in the DPB group (41.4 %), but in only 22 cases in the DPF group (26.8 %), and there was only a small significant difference within the DPF group. In the DPB group, there was one case of transient ischemic attack (TIA) (1.2 %) and four cases of brain infarction (2 minor strokes, 2 major strokes; 4.9 %), compared to the DFP group with one case of TIA (1.2 %) and no cases of minor or major strokes. CONCLUSIONS: In this study, significantly lower rates of occurrence of DWI ischemic lesions and intraoperative embolization were associated with use of the DPF compared to the DPB.

Carotid artery stenting in a patient with internal carotid artery stenosis and ipsilateral persistent primitive hypoglossal artery presenting with transient ischemia of the vertebrobasilar system: case report.

A 62-year-old man experienced transient episodes of vertigo associated with left upper extremity weakness. Cerebral angiography showed 75% right internal carotid artery (ICA) stenosis and divergence of a persistent primitive hypoglossal artery (PPHA) distal to the stenosis. The area of stenosis was at a high position and he had a past medical history of congestive heart failure, which contraindicated carotid endarterectomy (CEA). Therefore, carotid artery stenting (CAS) was performed with single distal balloon protection. The stenotic area was restored and he was discharged without suffering recurrent attacks. CAS may be an effective alternative treatment to CEA to prevent further ischemic attacks in the posterior circulation in patients with PPHA. CAS using simple embolic protection devices is possible if the distance between the distal end of the ICA stenosis and the origin of the PPHA is sufficiently long.

Shortening of Wallstent RP during carotid artery stenting requires appropriate stent placement.

Changes in the location and length of the Wallstent RP during carotid artery stenting (CAS) were evaluated using intraoperative videos of 28 patients with carotid artery stenosis who underwent CAS with a 10/20 mm Wallstent RP to determine the appropriate stent placement. The stent was deployed after its midpoint was positioned over a virtual center line, the perpendicular line which crossed the most stenotic point of the lesion on the road mapping image. The length of the stenotic lesion, the changes in the locations of the distal and proximal ends of the stent, and the changes in stent length were examined. The distal end of the stent moved a maximum of 6.1 mm toward the proximal side to a point 19.9 mm from the virtual center line. The proximal end moved a maximum of 11.3 mm toward the distal side to a point 14.7 mm from the virtual center line. The stent length ranged from 37.7 to 44.5 mm (mean 41.2 mm). The 10/20 mm Wallstent RP placed by our technique covers the entire lesion with no less than 5.7 mm of margin over the segment distal to the lesion in patients with stenotic segments shorter than 29.4 mm.

[Clinical efficacy of blood flow interruption using the HyperForm in right vertebral arteriovenous fistula--case report].

A 44-year-old male with right vertebral arteriovenous fistula accompanied with tinnitus, underwent endovascular treatment using GDC. A digital subtraction angiography clearly showed one fistula flowed from the right vertebral artery (VA) to the vertebral venous plexus, while the right VA close to the fistula was interupped with HyperForm. The tip of the micro catheter was placed in the vertebral venous plexus through fistula from the right VA, and the vertebral venous plexus around the fistula was embolized with 4 GDCs. Blood flow of the right VA was maintained. Follow-up angiography undertaken 6 months after the operation didn't show the recurrence of arteriovenous fistula.

Hemodynamic stability under general anesthesia in carotid artery stenting.

PURPOSE: The purpose of our study was to investigate the frequency of hemodynamic instability in patients undergoing carotid artery stenting (CAS) under general anesthesia using sevoflurane and nitrous oxide in oxygen. METHODS: A total of 97 consecutive CAS procedures were performed in 84 patients under sevoflurane anesthesia. The following hemodynamic variables were assessed: degree of systolic blood pressure change (deltaSBP) during CAS, hypotension, and bradycardia during and after CAS. RESULTS: During CAS, hypotension occurred in 43% of the patients, and bradycardia occurred in 14%. There was individual variation in the deltaSBP during CAS. Systolic blood pressure (SBP) change >50 mmHg was not seen in this series. After CAS, hypotension occurred in 24%, and bradycardia occurred in 10%. Cerebral infarction occurred in three cases. The stroke rate was 3.1% in this series. CONCLUSION: General anesthesia using sevoflurane and nitrous oxide in oxygen depressed barorecepter reflex sensitivity, induced hemodynamic stability under CAS, and may decrease the rate of occurrence of complications.

Dural AVFs of the cavernous sinus: transvenous embolization using a direct superficial temporal vein approach.

We present an alternative endovascular approach to treat dural anterio-venous fistulas (AVFs) of the cavernous sinus that drain only into the superior ophthalmic vein. Two cases of dural AVFs of the cavernous sinus producing increased intraocular pressure and diminishing visual acuity are reported. The cavernous sinus was accessed via the direct superficial temporal vein approach through the superior ophthalmic vein. Successful embolization was documented radiographically and clinically.

Internal carotid aneurysms presenting with mass effect symptoms of cranial nerve dysfunction: efficacy and imitations of endosaccular embolization with GDC.

OBJECTIVE: The authors report a retrospective analysis of their experience in the endosaccular embolization of internal carotid aneurysms which caused mass effect symptoms of cranial nerves (CN) and review the efficacy and limitations of this technique. METHODS: Between April 1997 and August 2002, 12 internal carotid aneurysms that caused mass effect symptoms of CN were treated by endosaccular GDC embolization with parent artery preservation. The locations were the cavernous internal carotid artery (CV) in six patients, carotid-ophthalmic artery (CO) in two patients, and posterior communicating artery (PCo) in four patients. The angiographical size of the aneurysms ranged from 6 to 20 mm, with a mean of 13.3 mm. Duration of symptoms ranged from 0.5 to 120 months, with a mean of 13.7 months. All aneurysms were treated by endosaccular guglielmi detachable coil (GDC) embolization with preservation of the internal carotid artery. RESULTS: Five patients (42%) had complete resolution of symptoms, four (33%) had significant improvement of symptoms, and three (25%) were unchanged. Immediate posttreatment angiographic studies revealed neck remnant (NR) in nine patients and dome filling (DF) in three patients. In one patient (case 10), the resolved symptoms became worse 29 months later. Follow-up angiograms were obtained in 10 patients, and recanalization was observed in four of them (40%). Transient thrombotic complication occurred in only one patient. The group with resolution or improvement of symptoms demonstrated a shorter duration of symptoms before GDC treatment (< or = 12 months). CONCLUSION: Even subtotal endosaccular embolization of aneurysms may reduce mass effect symptoms of cranial nerves. However, careful follow-up is needed because subtotal occlusion carries a future risk of growth.

Endovascular treatment of anterior cerebral artery aneurysms using Guglielmi detachable coils: mid-term clinical evaluation.

PURPOSE: Clinical and angiographic evaluations were performed in 19 consecutive patients with anterior communicating artery (ACoA) aneurysms treated by Guglielmi detachable coil (GDC) embolization between March 1997 and April 1999. METHODS: The angiographic criteria for endovascular treatment were 1) small (< 15 mm) aneurysm with a neck smaller than the fundus and 2) distinguishable aneurysm neck and relationship to the parent artery. Initially, we also included patients with anticipated surgical difficulties. These criteria were later expanded to include patients with conditions amenable to surgical clipping. Eleven patients presented with subarachnoid hemorrhage (SAH), and eight patients were asymptomatic. The most recent clinical follow-up was obtained by telephone interview with the patients and with their close relatives, to examine post-treatment personality changes. RESULTS: Complete obliteration (68%) or near-complete obliteration (neck remnant) (32%) of the ACoA aneurysm was achieved in all patients. Six-month follow-up angiography performed in 15 patients demonstrated no recurrence of aneurysms. The clinical outcome was good recovery in 15 (80%), moderately disabled in one (5%), vegetative survival in one (5%), and death in two (10%). The patients who had good recovery did not demonstarate significant personality or behavioral change. No late rebleeding had occurred at the time of writing, a minimum of 33 months postoperatively. CONCLUSION: The outcome of endovascular treatment of ACoA aneurysms was satisfactory, especially in post-treatment psychosocial sequelae.