Serological response to a third dose of SARS-CoV-2 vaccine according to previous infection history.

The IgG antibody titer against SARS-CoV-2 receptor binding protein (RBD) after mRNA vaccine were compared between those with and without previous infection (PI) for up to 48 weeks. Though sustained higher IgG-RBD were observed in the PI group after two doses of vaccines, both groups benefited from the booster shots of the third vaccine. This data supports the necessity of the booster shots to those with PI.

Fragmentation of calcified plaque after carotid artery stenting in heavily calcified circumferential stenosis.

INTRODUCTION: We assessed the morphological change of calcified plaque after carotid artery stenting (CAS) in vessels with heavily calcified circumferential lesions and discuss the possible mechanisms of stent expansion in these lesions. METHODS: We performed 18 CAS procedures in 16 patients with severe carotid artery stenosis accompanied by plaque calcification involving more than 75% of the vessel circumference. All patients underwent multidetector-row computed tomography (MDCT) to evaluate lesion calcification before and within 3 months after intervention. The angiographic outcome immediately after CAS and follow-up angiographs obtained 6 months post-CAS were examined. RESULTS: The preoperative mean arc of the calcifications was 320.1 +/- 24.5 degrees (range 278-360 degrees ). In all lesions, CAS procedures were successfully carried out; excellent dilation with residual stenosis

Intraprocedural plaque protrusion resulting in cerebral embolism during carotid angioplasty with stenting.

An 82-year-old man with an asymptomatic left high-grade carotid stenosis was treated with carotid artery stenting (CAS) under distal protection. The procedure consisted with predilation with a 5 x 40 mm percutaneous transluminal angioplasty (PTA) balloon, deployment of a 10 x 20 mm self-expandable stent, post-dilation with a 7 x 20 mm PTA balloon, and aspiration of debris with 60 ml of blood. The cervical carotid angiogram immediately after deflation of the distal blocking balloon demonstrated a small in-stent filling defect of the contrast medium that protruded from the anterior wall of the carotid artery. The following cranial carotid angiogram showed abrupt occlusion of the left middle cerebral artery (MCA). Because the in-stent lesion had vanished in the repeat study after recognition of this embolic event, it was suggested that an embolus had been liberated from the in-stent lesion, reaching the left MCA and obliterating it. In this case, the embolus was speculated to originate in the ruptured plaque, which protruded into the stent through the cells of the device and became liberated into the bloodstream. Attention should be paid so as not to overlook any plaque protrusion, which may be seen subsequently as a cerebral embolism on the angiogram obtained immediately after CAS.

Spasm induced by protection balloon during carotid artery stenting.

PURPOSE: The PercuSurge system is a distal balloon embolic protection device used for carotid artery stenting (CAS). We performed a retrospective study on the prognosis and clinical effects of spasms induced by the PercuSurge GuardWire system (PercuSurge-induced spasm). MATERIALS AND METHODS: We performed CAS in 118 carotid stenoses using the PercuSurge system. Of the 118 procedures, 31 (26.3%) of the patients experienced PercuSurge-induced spasm, and all underwent postoperative follow-up studies by cerebral angiography and antiplatelet treatment. RESULTS: On follow-up angiograms obtained a mean of 5.2 months (range 3-10 months) after CAS, all 31 PercuSurge-induced spasms had disappeared, and no delayed stenosis was found at the sites where the spasms had occurred. No ischemic events due to the spasms occurred during a mean follow-up of 13 months (range 3-32 months). CONCLUSION: In the hands of physicians experienced in endovascular surgery, CAS using the PercuSurge system is a safe method with which to treat patients with carotid stenosis. Our study demonstrated that PercuSurge-induced spasms had no morphological or clinical adverse effects.

Rebleeding after endovascular embolization of ruptured cerebral aneurysms.

This study retrospectively reviewed 227 patients with ruptured solitary cerebral aneurysm who underwent endovascular embolization with detachable coils between March 1997 and March 2006 to establish the incidence of rebleeding after endovascular treatment for ruptured cerebral aneurysm and identify the risk factors. The site and size of the aneurysm, the interval between treatment and rebleeding, and the outcome were investigated in six of the 227 patients (2.6%) who rebled after treatment. Four patients had large or giant aneurysms located on the internal carotid artery at the origin of the posterior communicating artery. The interval between treatment and rebleeding was less than 1 year in four patients (mean 394.2 days). Two patients died, and the survivors had modified Rankin Scale scores of 0, 2, 3, and 4. Re-embolization was performed in four patients and no further bleeding occurred during the mean follow-up period of 1.9 years after re-treatment. Patients with giant aneurysms of the internal carotid artery are at increased risk for rebleeding. Re-treatment should be considered if there is conventional and/or magnetic resonance angiographic evidence of dome filling. Patients with ruptured cerebral aneurysms must be followed up with diagnostic imaging closely during the first 12 months post-embolization because rebleeding frequently occurs within 1 year after initial treatment. Re-embolization is safe and effective in patients with recurrent hemorrhage from aneurysms previously embolized with detachable coils.

Cerebral protection during retrograde carotid artery stenting for proximal carotid artery stenosis: technical note.

Carotid artery stenting for carotid bifurcation stenosis usually uses the transfemoral approach. However, in patients with proximal common carotid artery (CCA) stenosis, the guiding catheter is difficult to introduce into the narrow origin of the CCA without risking cerebral embolization before activation of the protection device. A technique of cerebral protection by internal carotid artery (ICA) clamping with or without simultaneous external carotid artery (ECA) clamping was used to treat patients with proximal CCA stenosis by the retrograde direct carotid approach. The carotid bifurcation was surgically exposed and retrograde catheterization was performed to approach the stenosis. The ICA was clamped during angioplasty and stenting to avoid cerebral embolization. The ECA was clamped simultaneously if any extracranial-intracranial anastomosis was present. None of five patients treated with this technique experienced ischemic complications attributable to this technique.

[Case of ruptured superior cerebellar artery dissection treated by endovascular embolization].

The authors herein report a case of a ruptured dissection of the superior cerebellar artery (SCA). A 68-year-old man presented with symptons of sudden headache and nausea. The CT scan revealed the presence of both a subarachnoid hemorrhage (SAH) and acute hydrocephalus. The left vertebral angiogram showed an fusiform dilatation in the cerebellomesencephalic segment of the left SCA. Endovascular embolization of the aneurysm and SCA was successfully performed using Guglielmi detachable coils (GDCs). No delayed ischemic deficits were observed after the treatment. A dissection of the distal segment of the SCA is a very rare occurrence. We believe endovascular embolization using GDCs to be an effective and less invasive therapy for the treatment of an SCA dissection with SAH.

Factors affecting rapid growth of unruptured cerebral aneurysms during the acute stage of subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: Several unruptured cerebral aneurysms have been reported to grow and rupture. To determine which factors affect the growth of these aneurysms during the acute stage of subarachnoid hemorrhage (SAH), a retrospective review was performed. METHODS: Between January 2000 and January 2003, 130 patients with angiographically proven ruptured cerebral aneurysms were treated at our institution. Of these patients, 32 also had simultaneous unruptured aneurysms, and the total number of the unruptured aneurysms was 40, including two neck remnants which had remained since the past clipping. Seventeen patients had 17 unruptured aneurysms and two neck remnants. The unruptured aneurysms were not treated during the acute stage of SAH but had received a complete short term follow-up. RESULTS: The rapid growth of one unruptured aneurysm and two neck remnants was confirmed by a second angiogram performed on average 40 days after the first angiogram. Several candidate factors responsible for the growth of aneurysm were selected, and the results of a statistical analysis indicate that a systolic blood pressure above 200 mmHg during the acute stage of SAH and vasospasm, confirmed by transcranial Doppler ultrasound (TCD) or neurological examination, and neck remnants, are risk factors that affect the growth. CONCLUSIONS: Short term follow-up angiography is thus important for patients with untreated unruptured cerebral aneurysms after the acute stage of SAH.

Hyperform remodeling balloon for the balloon occlusion test of persistent primitive trigeminal artery aneurysm - case report.

A 17-year-old woman presented with a rare aneurysm at the junction of the persistent primitive trigeminal artery (PPTA) and the internal carotid artery (ICA) manifesting as left abducens nerve paresis. The aneurysm and the ICA were both successfully occluded with coils. The balloon occlusion test used the HyperForm balloon microcatheter to seal the PPTA and ICA, which is very important to determine the optimal treatment strategy for a PPTA aneurysm.

Morphology of elastase-induced cerebral aneurysm model in rabbit and rapid prototyping of elastomeric transparent replicas.

In this work, we describe a methodology to fabricate transparent elastomeric vascular replicas using rapid prototyping techniques. First, the three-dimensional morphology of an elastase-induced aneurysm model in rabbit is acquired. The morphology is reconstructed from in vivo rotational angiography and it is compared with three-dimensional reconstructions obtained by computerized tomography and magnetic resonance imaging of an intraluminal arterial cast that was obtained from the same animal at sacrifice. Results show that resolution of the imaging modality strongly influences the level of detail, such as small side branches, in the final reconstruction. We developed an average morphology model for elastase-induced aneurysms in rabbits including the surrounding vasculature and describe a method for rapid prototyping of vascular models from the three-dimensional morphology. Our replicas can be manufactured in a short period of time and the final product is optically clear. In addition, the elasticity of the models can be controlled to represent arterial elasticity, which makes them ideal for optical investigations of detailed flow dynamics using measurement tools such as particle image velocimetry.

Giant fusiform aneurysms in the middle cerebral artery presenting with hemorrhages of different origins. Report of three cases and review of the literature.

Three cases of giant fusiform aneurysms in the middle cerebral artery (MCA) presenting with hemorrhages of different origins are reported, and appropriate literature is reviewed to investigate the characteristics of these lesions. Two patients had suffered a subarachnoid hemorrhage and the other had an intramural hemorrhage (dissection). Pathologically, these aneurysms presented with hemorrhages of different origins; classic rupture type (Case 1), dissection type (Case 2), and atherosclerosis-related thrombosis type (Case 3). Based on surgical and pathological investigations in these three cases and a review of the reported literature, the authors propose that giant fusiform aneurysms in the MCA are characterized by weaknesses in the internal elastic lamina with intimal thickening. Therefore, these lesions have the potential to present with hemorrhage in each of the three types. This finding indicates that there is a strong relationship between the pathological features of giant fusiform aneurysms and their clinical course, and that it is necessary to determine appropriate therapy for giant fusiform aneurysms in the MCA by evaluating cerebral blood flow, even if the lesions are found incidentally.

Ruptured aneurysm at the choroidal branch of the posterior inferior cerebellar artery: a case report and review of the literature.

BACKGROUND: The authors present a rare case of a ruptured aneurysm at the choroidal branch of the posterior inferior cerebellar artery (PICA). CASE DESCRIPTION: A 77-year-old female was admitted to our institute because of sudden onset of severe headache and vomiting. Radiologic examination revealed intraventricular hemorrhage caused by rupture of the aneurysm at the choroidal branch of the PICA. The fusiform aneurysm was resected after ligation via a midline suboccipital approach. CONCLUSIONS: The conclusions drawn from this experience and a review of the literature include the following: (1) the aneurysm at the branch of the PICA is frequently associated with anomalies of the vascular structure, particularly in hypoplasty of the contralateral PICA; (2) hemodynamic stress is speculated to be a causative factor of these lesions; (3) cases with hypoplasty of the contralateral PICA have the possibility of developing nonmycotic peripheral aneurysms at the branch of the PICA; (4) these aneurysms should be managed immediately because of the high risk of rebleeding.

Retrospective analysis of neurological outcome after intra-arterial thrombolysis in basilar artery occlusion.

BACKGROUND: Basilar artery occlusion usually has a very poor outcome and is associated with a high mortality rate. Local intra-arterial thrombolysis may improve the clinical outcome and reduce mortality in the treatment of acute basilar artery occlusion. We evaluated the possible variables affecting recanalization and clinical outcome in patients with basilar artery occlusions undergoing thrombolytic therapy. METHODS: We analyzed retrospectively the clinical course and outcome of a series of 26 patients between 1998 and 2001. All patients who were examined within 24 hours after onset of symptoms underwent emergency cerebral angiography and subsequent intra-arterial thrombolysis. Three patients additionally received percutaneous transluminal angioplasty of underlying stenosis at the site of thrombosis. RESULTS: Outcome was good in 9 patients (34.6%) and poor in 17 (65.4%). Recanalization could be achieved in 24 patients (92.3%) and was not affected by age, sex, site of occlusion, etiology, thrombolytic drugs, or time interval. Good outcome was associated with younger age, good initial clinical condition, and no evidence of brain stem infarction. There was no association between the interval (greater or less than 6 hours) from the onset of symptoms until the end of thrombolysis and survival. CONCLUSIONS: We confirm that intra-arterial thrombolysis reduces mortality in basilar artery occlusion. Young patients (<75 years) without any infarct in brain stem before the start of treatment seem to be the ideal candidates for thrombolysis. Basilar artery thrombosis could and should be reopened, even late (after 6 hours) after symptom onset.

Gamma knife surgery for the treatment of spontaneous dural carotid-cavernous fistulas.

Endovascular treatment for a spontaneous dural carotid-cavernous fistula (CCF) is an established treatment, but stereotactic radiosurgery might provide a less-invasive alternative in selected cases. Four women aged 67 to 79 years (mean 72.0 years) with spontaneous dural CCFs presented with chemosis or bruit. Angiography revealed arteriovenous fistulas in the cavernous portion. Three cases were Barrow type D and one was type B converted from type D. Stereotactic gamma knife surgery was performed with a marginal dose of 13-15 Gy and a maximum dose of 26-30 Gy with a volume from 824 to 1755 mm3. The target point of radiosurgery for type D CCFs was the compartment of the cavernous sinus supplied by multiple feeders from the external carotid artery. All patients responded favorably to the treatment, with improvement of symptoms beginning after 1 to 3 months. Angiography confirmed the complete disappearance of the CCFs in all patients. There were no recurrences, and the follow-up period was 14 to 32 months (mean 24 months). No significant side effects were observed. Stereotactic radiosurgery is a useful method to treat CCFs and is indicated for elderly patients, low-flow CCFs, and cases in which endovascular treatment has failed.

[Isolated posterior cerebral artery dissection--case report and review of the literature].

Although dissecting aneurysms appear not to be as rare as previously reported, their etiology remains unclear. We describe a rare case of a girl with ischemia in the region of the posterior cerebral artery (PCA). The patient complained of a mild headache and left upper paresthesia. Neurological findings revealed a mild left hemiparesis. Visual field was intact, and cardiac embolism was excluded due to the almost normal chest X-p, ECG, and UCG. Laboratory findings were within normal limits. However, MRA and angiography revealed a linear shadow and an irregular caliber change at the right P1-P2 segment. Conservative therapy was pursued and the patient showed full neurological recovery. After a 3-month follow-up period, MRI showed no recurrence and MRA showed that the lesion had returned to normal. Here, we report the case as well as review the literature relating to this disorder, including discussion of its etiology, clinical features, radiological findings, and management strategies. We conclude that this disorder should be taken into consideration as a differential diagnosis of cerebrovascular disease in young people.

Spontaneous superficial temporal artery pseudoaneurysm in elderly women--three case reports.

Three women older than 75 years presented with spontaneous superficial temporal artery (STA) pseudoaneurysms manifesting as a pulsatile mass in the preauricular region. None of the patients had a history of trauma. Histological examination of the surgically removed masses identified pseudoaneurysms based on the presence of connective tissue and adventitia. Spontaneous STA pseudoaneurysms are extremely rare. We suggest that all 3 aneurysms were associated with latent dissection and external force exerted by the frames of glasses.

Intraprocedural changes in angiographic cerebral circulation time predict cerebral blood flow after carotid artery stenting.

Changes in the cerebral blood flow (CBF) are important for planning postoperative care in patients treated by carotid artery stenting (CAS). The relationship between intraprocedural changes in the angiographic cerebral circulation time (CCT) and perioperative CBF changes were retrospectively studied in 49 CAS procedures performed in 46 patients with carotid artery stenosis. The CCT, defined as the interval between the timing of maximal opacification at the terminal portion of the internal carotid artery and at the cortical vein, was determined by referring to time-density curves of data obtained from routine intraprocedural digital subtraction angiography. The intraoperative change in CCT (Delta CCT) was calculated for each of the 49 procedures. CBF studies, using dynamic perfusion computed tomography, were performed 10-2 days before and 2-4 days after CAS. Perioperative changes in the ratio of the CBF in the territory of the middle cerebral artery on the affected side to CBF on the contralateral side (%CBF) were calculated by subtracting pre- from postoperative %CBF (Delta%CBF) and the correlation between Delta CCT and Delta%CBF was evaluated. Mean CCT was shortened by 1.1 seconds from 5.3 to 4.2 seconds after CAS. Mean %CBF increased by 11.9% from 91.8% to 103.7% after the procedure. Delta CCT and Delta%CBF showed a significant positive correlation (r = 0.61, p = 0.008). Intraprocedural changes in angiographic CCT are predictive of postoperative CBF in patients with CAS.

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.

Endovascular treatment of tiny ruptured anterior communicating artery aneurysms.

INTRODUCTION: Because of its high complication rate, the endovascular treatment (EVT) of anterior communicating artery (ACoA) aneurysms less than 3 mm in maximum diameter remains controversial. We evaluated EVT of tiny ruptured ACoA aneurysms with Guglielmi detachable coils (GDCs). METHODS: We treated 19 ruptured ACoA aneurysms with a maximum diameter of

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.