Endovascular Treatment for Intracranial Artery Dissections in Posterior Circulation.

Intracranial artery dissections (IADs), although uncommon, are an important cause of cerebral infarction and subarachnoid hemorrhage (SAH). Some IADs can heal spontaneously after reconstitution of the vessel lumen with excellent prognosis. Meanwhile, others can progress to stroke that requires treatment. The incidence of IAD in the posterior circulation is higher than that in the anterior circulation. Anterior circulation dissections are more likely to develop into ischemia and posterior circulation lesions into hemorrhage. The mortality rate after IAD among patients with SAH is 19%-83%. Further, the mortality rate of IAD without SAH is 0%-3%. Patients with SAH commonly undergo surgery or receive neuroendovascular treatment (EVT) to prevent rebleeding. However, the treatment of IADs is empirical in the absence of data from randomized controlled trials. Recently, EVT has emerged and is considered for IADs because of its less invasiveness and perceived low rates of procedure-related morbidity with good efficacy. EVT strategies can be classified into deconstructive (involving sacrifice of the parent artery) and reconstructive (preserving blood flow via the parent vessel) techniques. In particular, the number of reports on reconstructive techniques is increasing. However, a reconstructive technique for ruptured IADs has not yet been established. This review aimed to provide an overview of IADs in the posterior circulation managed with EVT by performing a literature search.

Transvenous embolization of the direct carotid-cavernous fistula via the pterygoid plexus: illustrative case.

BACKGROUND: Endovascular treatment is the mainstay of treatment for carotid-cavernous fistulas, but endovascular approaches vary widely. The authors report a rare case of a direct carotid-cavernous fistula with cranial nerve symptoms caused by rupture of a giant aneurysm in which selective transvenous embolization via the pterygoid plexus was performed. OBSERVATIONS: An 81-year-old man presented with headache and various progressive cranial nerve symptoms due to a direct carotid-cavernous fistula caused by a ruptured giant aneurysm. All the draining veins visualized on preoperative examination immediately before the treatment were occluded except for the pterygoid plexus. Therefore, the authors chose the dilated pterygoid plexus to approach the shunted pouch at the cavernous sinus and achieve shunt obliteration by selective embolization with coils and n-butyl cyanoacrylate. LESSONS: Careful study of the three-dimensional rotational images in the preoperative examination is important when considering the various approaches to surgery. The pterygoid plexus can be an effective venous approach route to reach the cavernous sinus area.

Angioarchitecture of the Normal Lateral Spinal Artery and Craniocervical Junction Arteriovenous Fistula Using Contrast-enhanced Cone-beam CT.

BACKGROUND AND PURPOSE: The lateral spinal artery (LSA) perfuses the dorsolateral part of the spinal cord at the craniocervical junction (CCJ). We analyzed the angioarchitecture of the normal LSA and CCJ arteriovenous fistula (AVF). METHODS: The first study included 26 patients with a cerebral aneurysm of the posterior circulation. Using slab maximum intensity projection (MIP) images from three-dimensional rotational angiography (3D-RA) and contrast-enhanced cone-beam CT (CE-CBCT), we analyzed the origin of the LSA, its anastomosis with the posterior inferior cerebellar artery (PICA), the point where it reaches the spinal cord, and the visualized range. In the second study, we analyzed the angioarchitecture and treatment results of 7 CCJAVF lesions treated in our department between 2016 and 2021. RESULTS: We visualized the normal LSA for all patients. In 23 patients with an intradural origin PICA, all LSAs originated from the C1 or C2 radicular artery, and 8 patients had an anastomosis with the PICA. In three patients with a C1 level origin PICA, all LSAs originated from the PICA. All LSAs reached the dorsolateral part of the spinal cord. The mean visualized range of the LSA was 27.4 mm. The LSA was involved in five of seven CCJAVF lesions (71%). There was one lesion with a spinal infarction after LSA embolization. Other lesions were treated by direct interruption of the AVF, and the ASA and LSA were preserved. CONCLUSION: This is the first report that visualized the LSA's normal anatomy using slab MIP images from 3D-RA and CE-CBCT. Knowledge of LSA anatomy is critical to avoid complications during the treatment of CCJAVF.

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.

Evaluation of Heat Inactivation of Human Norovirus in Freshwater Clams Using Human Intestinal Enteroids.

Foodborne disease attributed to the consumption of shellfish contaminated with human norovirus (HuNoV) is one of many global health concerns. Our study aimed to determine the conditions of the heat-inactivation of HuNoV in freshwater clams (Corbicula japonica) using a recently developed HuNoV cultivation system employing stem-cell derived human intestinal enteroids (HIEs). We first measured the internal temperature of the clam tissue in a water bath during boiling at 90 °C and found that approximately 2 min are required for the tissue to reach 90 °C. Next, GII.4 HuNoV was spiked into the center of the clam tissue, followed by boiling at 90 °C for 1, 2, 3, or 4 min. The infectivity of HuNoV in the clam tissue homogenates was evaluated using HIEs. We demonstrated that HuNoV in unboiled clam tissue homogenates replicated in HIEs, whereas infectivity was lost in all boiled samples, indicating that heat treatment at 90 °C for 1 min inactivates HuNoV in freshwater clams in our current HIE culture system. To our knowledge, this is the first study to determine the thermal tolerability of HuNoV in shellfish using HIEs, and our results could be informative for developing strategies to inactivate HuNoV in shellfish.

A case of delayed foreshortening and disconnection of pipeline embolization device detected by chronological cone-beam computed tomography fusion image.

OBJECTIVE: The morphological changes of the pipeline embolization device (PED; Medtronic, Minneapolis, MN, USA), such as delayed migration or foreshortening, can relate to the incomplete occlusion of aneurysms. CASE PRESENTATION: A 30-year-old man with a giant cavernous carotid artery aneurysm was treated with two PEDs using the overlapping technique. Six months after treatment, follow-up angiography showed morphological changes of the PEDs and residual flow into the aneurysm. Chronological cone-beam computed tomography fusion imaging clearly revealed the dynamic foreshortening of the first PED and the disconnection of both PEDs, so we decided to implant an additional PED. CONCLUSION: This case illustrates that a three-dimensional understanding can be useful for assessing the cause of treatment failure or recurrence.

Incidence and clinical characteristics of spinal arteriovenous shunts: hospital-based surveillance in Okayama, Japan.

OBJECTIVE: There have been no accurate surveillance data regarding the incidence rate of spinal arteriovenous shunts (SAVSs). Here, the authors investigate the epidemiology and clinical characteristics of SAVSs. METHODS: The authors conducted multicenter hospital-based surveillance as an inventory survey at 8 core hospitals in Okayama Prefecture between April 1, 2009, and March 31, 2019. Consecutive patients who lived in Okayama and were diagnosed with SAVSs on angiographic studies were enrolled. The clinical characteristics and the incidence rates of each form of SAVS and the differences between SAVSs at different spinal levels were analyzed. RESULTS: The authors identified a total of 45 patients with SAVSs, including 2 cases of spinal arteriovenous malformation, 5 cases of perimedullary arteriovenous fistula (AVF), 31 cases of spinal dural AVF (SDAVF), and 7 cases of spinal epidural AVF (SEAVF). The crude incidence rate was 0.234 per 100,000 person-years for all SAVSs including those at the craniocervical junction (CCJ) level. The incidence rate of SDAVF and SEAVF combined increased with advancing age in men only. In a comparative analysis between upper and lower spinal SDAVF/SEAVF, hemorrhage occurred in 7/14 cases (50%) at the CCJ/cervical level and in 0/24 cases (0%) at the thoracolumbar level (p = 0.0003). Venous congestion appeared in 1/14 cases (7%) at the CCJ/cervical level and in 23/24 cases (96%) at the thoracolumbar level (p < 0.0001). CONCLUSIONS: The authors reported detailed incidence rates of SAVSs in Japan. There were some differences in clinical characteristics of SAVSs in the upper spinal levels and those in the lower spinal levels.

A New Method of Intracranial Aneurysm Modeling for Stereolithography Apparatus 3D Printer: The "Wall-Carving Technique" Using Digital Imaging and Communications in Medicine Data.

OBJECTIVE: To assess the ability of the "wall-carving (WC) image technique", which uses vascular images from 3-dimensional digital subtraction angiograms (3DDSAs). Also, to verify the accuracy of the resulting 3D-printed hollow models of intracranial aneurysms. METHODS: The 3DDSA data from 9 aneurysms were processed to obtain volumetric models suitable for the stereolithography apparatus. The resulting models were filled with iodinated contrast media. 3D rotational angiography of the models was carried out, and the aneurysm geometry was compared with the original patient data. The accuracy of the 3D-printed hollow models' sizes and shapes was evaluated using the nonparametric Wilcoxon signed-rank test and the Dice coefficient index. RESULTS: The aneurysm volumes ranged from 34.1 to 4609.8 mm3 (maximum diameters 5.1-30.1 mm), and no statistically significant differences were noted between the patient data and the 3D-printed models (P = 0.4). Shape analysis of the aneurysms and related arteries indicated a high level of accuracy (Dice coefficient index value: 88.7%-97.3%; mean ± SD: 93.6% ± 2.5%). The vessel wall thickness of the 3D-printed hollow models was 0.4 mm for the parent and 0.2 mm for small branches and aneurysms, almost the same as the patient data. CONCLUSIONS: The WC technique, which involves volume rendering of 3DDSAs, can provide a detailed description of the contrast enhancement of intracranial vessels and aneurysms at arbitrary depths. These models can provide precise anatomic information and be used for simulations of endovascular treatment.

Dasabuvir Inhibits Human Norovirus Infection in Human Intestinal Enteroids.

Human noroviruses (HuNoVs) are acute viral gastroenteritis pathogens that affect all age groups, yet no approved vaccines and drugs to treat HuNoV infection are available. In this study, we screened an antiviral compound library to identify compound(s) showing anti-HuNoV activity using a human intestinal enteroid (HIE) culture system in which HuNoVs are able to replicate reproducibly. Dasabuvir (DSB), which has been developed as an anti-hepatitis C virus agent, was found to inhibit HuNoV infection in HIEs at micromolar concentrations. Dasabuvir also inhibited severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and human rotavirus A (RVA) infection in HIEs. To our knowledge, this is the first study to screen an antiviral compound library for HuNoV using HIEs, and we successfully identified dasabuvir as a novel anti-HuNoV inhibitor that warrants further investigation. IMPORTANCE Although there is an urgent need to develop effective antiviral therapy directed against HuNoV infection, compound screening to identify anti-HuNoV drug candidates has not been reported so far. Using a human HIE culture system, our compound screening successfully identified dasabuvir as a novel anti-HuNoV inhibitor. Dasabuvir's inhibitory effect was also demonstrated in the cases of SARS-CoV-2 and RVA infection, highlighting the usefulness of the HIE platform for screening antiviral agents against various viruses that target the intestines.

Trends in Incidence of Intracranial and Spinal Arteriovenous Shunts: Hospital-Based Surveillance in Okayama, Japan.

BACKGROUND AND PURPOSE: To date, the incidence of intracranial and spinal arteriovenous shunts has not been thoroughly investigated. We aimed to clarify recent trends in the rates of intracranial and spinal arteriovenous shunts in Japan. METHODS: We conducted multicenter hospital-based surveillance at 8 core hospitals in Okayama Prefecture between April 1, 2009 and March 31, 2019. Patients who lived in Okayama and were diagnosed with cerebral arteriovenous malformations, dural arteriovenous fistulas (DAVFs), or spinal arteriovenous shunts (SAVSs) were enrolled. The incidence and temporal trends of each disease were calculated. RESULTS: Among a total of 393 cranial and spinal arteriovenous shunts, 201 (51.1%) cases of DAVF, 155 (39.4%) cases of cerebral arteriovenous malformation, and 34 (8.7%) cases of SAVS were identified. The crude incidence rates between 2009 and 2019 were 2.040 per 100 000 person-years for all arteriovenous shunts, 0.805 for cerebral arteriovenous malformation, 1.044 for DAVF, and 0.177 for SAVS. The incidence of all types tended to increase over the decade, with a notable increase in incidence starting in 2012. Even after adjusting for population aging, the incidence of nonaggressive DAVF increased 6.0-fold while that of SAVS increased 4.4-fold from 2010 to 2018. CONCLUSIONS: In contrast to previous studies, we found that the incidence of DAVF is higher than that of cerebral arteriovenous malformation. Even after adjusting for population aging, all of the disease types tended to increase in incidence over the last decade, with an especially prominent increase in SAVSs and nonaggressive DAVFs. Various factors including population aging may affect an increase in DAVF and SAVS.

Osseous arteriovenous fistulas in the dorsum sellae, clivus, and condyle.

PURPOSE: Arteriovenous fistulas (AVFs) located in the cavernous sinus (CS), clivus, and condyle can be osseous shunts in nature. Here, we reviewed the angioarchitecture, clinical characteristics, and treatment results of AVFs in these lesions. METHODS: Twenty-five patients with 27 lesions who underwent rotational angiography in our department between May 2013 and December 2019 were reviewed. We examined 20 CS AVFs, 2 clival AVFs, and 5 condylar AVFs. We divided the anatomical shunted pouches into five locations: the dorsum sellae (posteromedial of the CS), posterolateral wall of the CS, lateral wall of the CS, clivus, and condyle. We divided the AVFs into three categories: intraosseous, transitional, and nonosseous shunts. We analyzed the characteristics and treatment results. RESULTS: A total of 33 shunted pouches or points were identified in 27 lesions. The dorsum sellae (n = 16) was the most frequent location. Fourteen AVFs (88%) in the dorsum sellae were osseous (intraosseous or transitional) shunts. All AVFs in the clivus or condyle were also osseous shunts. Eleven lesions (92%) of intraosseous and all lesions of transitional shunts exhibited bilateral external carotid artery involvement as feeders. Ten lesions (83%) of intraosseous shunts were treated with selective transvenous embolization of the shunted pouch with or without additional partial embolization of the sinus. Eleven (92%) intraosseous shunts were completely occluded, and symptom resolution was achieved in all intraosseous shunts. CONCLUSION: Most of the CS AVFs with shunted pouches in the dorsum sellae and all of the AVFs in the clivus and condyle share similar characteristics.

Detection of the common origin of the radiculomedullary artery with the feeder of spinal dural arteriovenous fistula using slab maximum intensity projection image.

PURPOSE: Endovascular therapy to the spinal dural arteriovenous fistula (SDAVF) with a common origin of the radiculomedullary artery and the feeder of the shunt has the risk of spinal cord infarction. This study aimed to retrospectively assess the detection rate of normal spinal arteries from the feeder of SDAVF. METHODS: We retrospectively collected the angiographic and clinical data of SDAVFs. This study included 19 patients with 20 SDAVF lesions admitted to our department between January 2007 and December 2018. We assessed the detection rate of normal radiculomedullary artery branched from the feeder of SDAVF between the period using the image intensifier (II) and flat panel detector (FPD) and evaluated the treatment results. RESULTS: The detection rates of the radiculomedullary artery branched from the feeder of SDAVF were 10% (1/10 lesions) during the II period and 30% (3/10 lesions) during the FPD period. During the FPD period, all normal radiculomedullary arteries branched from the feeder were only detected on slab maximum intensity projection (MIP) images of rotational angiography, and we could not detect them in 2D or 3D digital subtraction angiography. All lesions that had a common origin of a normal radiculomedullary artery and the feeder were completely obliterated without complications. There was no recurrence during the follow-up period. CONCLUSIONS: The flat panel detector and slab MIP images seem to show the common origin of the normal radiculomedullary arteries from the feeder more accurately. With detailed analyses, SDAVF can be safety treated.

Safety and efficacy of staged angioplasty for patients at risk of hyperperfusion syndrome: a single-center retrospective study.

PURPOSE: Intracranial hemorrhage following hyperperfusion syndrome (HPS) is a rare but potentially fatal complication after carotid artery stenting (CAS). Staged angioplasty (SAP) is a two-stage form of CAS that can prevent the abrupt increase of cerebral blood flow. In this study, we investigated the safety and efficacy of SAP. METHODS: One hundred thirty-four patients who underwent CAS for high-grade carotid artery stenosis between January 2010 and December 2018 were enrolled. Patients who showed severe impairment of hemodynamic reserve in 123I-IMP SPECT with acetazolamide received SAP (SAP group), while the others received regular CAS (RS group). RESULTS: Twenty-six (19.4%) patients at risk for HPS received SAP. HPS was not observed in either group. Diffusion-weighted image (DWI)-positive lesions on postoperative MRI were observed in 56 (52.3%) cases in the RS group and 16 (64.0%) cases in the SAP group. Symptomatic procedure-related complications occurred in 5 (4.6%) cases in the RS group and 1 (3.8%) case in the SAP group. These differences were not statistically significant. Modified Rankin Scale score had declined 30 days after discharge in 4 (3.0%) cases. Distal filter protection was significantly correlated to the occurrence of new DWI-positive lesions. CONCLUSIONS: For patients at high risk of HPS, SAP was a reasonable treatment strategy to prevent HPS. SAP did not increase the rate of DWI-positive lesions or procedure-related complications compared with regular CAS.

Dural Arteriovenous Fistulas in the Parasellar Region Other Than the Cavernous Sinus.

Besides cavernous sinus (CS) dural arteriovenous fistulas (AVFs), AVF may develop around the parasellar region. They can cause various symptoms, and some of them may show similar symptoms to those of CS dural AVF. Therefore, these AVFs may be misdiagnosed as CS dural AVFs. In this review, we divided parasellar AVFs into four groups based on their locations related to the CS: anterior group (orbit), anterolateral group (sphenoid wing), posteroinferior group (inferior petrosal sinus and clivus), and posterior group (superior petrosal sinus and petrosal vein). Although parasellar AVFs share common points, there are many differences between the four groups. We herein discuss commonalities and differences in parasellar AVFs based on a review of the literature and our experience.