Masafumi Hiramatsu

Epidemiology of Dural Arteriovenous Fistula in Japan: Analysis of Japanese Registry of Neuroendovascular Therapy (JR-NET2)

We developed the Japanese Registry of Neuroendovascular Therapy 2 (JR-NET2) database and used the information for a retrospective, nation-wide multicenter, observational study to clarify the clinical characteristics, current status of procedures, and outcome of patients treated by neuroendovascular therapy in Japan. In this report, we analyzed the clinical characteristics of dural arteriovenous fistulas (dAVFs) in the JR-NET2 database. All patients with dAVFs treated with endovascular therapy in 150 Japanese hospitals were included. Patient characteristics, clinical presentations, and imaging characteristics were analyzed. A total of 1,075 patients with dAVFs underwent 1,520 endovascular procedures. Of 1,075 patients, 45% were men and 55% were women. The mean age was 65 ± 13 years. The most frequent location of dAVFs was the cavernous sinus (43.6%), followed by the transverse-sigmoid sinus (TSS) (33.4%). Twelve percent of the patients had intracranial hemorrhage, 9% had venous infarction, and 3% had convulsion. The statistically significant independent risk factors of intracranial hemorrhage were TSS, superior sagittal sinus (SSS), tentorium, anterior cranial fossa, cranio-cervical junction, cortical venous reflux (CVR), and varix. Risk factors of venous infarction were age older than 60 years, male sex, TSS, SSS, and CVR. Risk factors of convulsion were male sex, SSS, and CVR. This is the largest nationwide report, to date, of the clinical characteristics of dAVFs treated by neuroendovascular therapy. CVR was a major risk factor of aggressive symptoms.

Cerebral vasospasm in patients over 80 years treated by coil embolization for ruptured cerebral aneurysms.

Object. The effect on clinical outcomes of symptomatic vasospasm after aneurysmal subarachnoid hemorrhage (SAH) in patients over 80 years who underwent coil embolization was evaluated. Methods. Forty-four cases were reviewed and divided into two groups according to patient age: Group A, 79 years or younger, and Group B, 80 or older. Patient characteristics, prevalence of symptomatic vasospasm, modified Rankin Scale (mRS) scores at discharge and frequency of symptomatic vasospasm in patients with mRS scores of 3–6 were analyzed. Results. Thirty-two (73%) of the 44 cases were categorized as Group A and 12 (27%) as Group B. Group B had a significantly higher prevalence of symptomatic vasospasm compared to Group A (P = 0.0040). mRS scores at discharge were significantly higher in Group B than in Group A (P = 0.0494). Among cases with mRS scores of 3–6, there was a significantly higher frequency of symptomatic vasospasm in Group B than in Group A (P = 0.0223). Conclusions. In our cohort of aneurysmal SAH patients treated by coil embolization, patients over 80 years of age were more likely to suffer symptomatic vasospasm, which significantly correlated with worse clinical outcomes, than those 79 years and under.

Angiographic and Clinical Characteristics of Thoracolumbar Spinal Epidural and Dural Arteriovenous Fistulas

Background and Purpose— The purpose of this study is to compare the angiographic and clinical characteristics of spinal epidural arteriovenous fistulas (SEAVFs) and spinal dural arteriovenous fistulas (SDAVFs) of the thoracolumbar spine. Methods— A total of 168 cases diagnosed as spinal dural or extradural arteriovenous fistulas of the thoracolumbar spine were collected from 31 centers. Angiography and clinical findings, including symptoms, sex, and history of spinal surgery/trauma, were retrospectively reviewed. Angiographic images were evaluated, with a special interest in spinal levels, feeders, shunt points, a shunted epidural pouch and its location, and drainage pattern, by 6 readers to reach a consensus. Results— The consensus diagnoses by the 6 readers were SDAVFs in 108 cases, SEAVFs in 59 cases, and paravertebral arteriovenous fistulas in 1 case. Twenty-nine of 59 cases (49%) of SEAVFs were incorrectly diagnosed as SDAVFs at the individual centers. The thoracic spine was involved in SDAVFs (87%) more often than SEAVFs (17%). Both types of arteriovenous fistulas were predominant in men (82% and 73%) and frequently showed progressive myelopathy (97% and 92%). A history of spinal injury/surgery was more frequently found in SEAVFs (36%) than in SDAVFs (12%; P=0.001). The shunt points of SDAVFs were medial to the medial interpedicle line in 77%, suggesting that SDAVFs commonly shunt to the bridging vein. All SEAVFs formed an epidural shunted pouch, which was frequently located in the ventral epidural space (88%) and drained into the perimedullary vein (75%), the paravertebral veins (10%), or both (15%). Conclusions— SDAVFs and SEAVFs showed similar symptoms and male predominance. SDAVFs frequently involve the thoracic spine and shunt into the bridging vein. SEAVFs frequently involve the lumbar spine and form a shunted pouch in the ventral epidural space draining into the perimedullary vein.

NADH fluorescence imaging and the histological impact of cortical spreading depolarization during the acute phase of subarachnoid hemorrhage in rats

OBJECTIVE Although cortical spreading depolarization (CSD) has been observed during the early phase of subarachnoid hemorrhage (SAH) in clinical settings, the pathogenicity of CSD is unclear. The aim of this study is to elucidate the effects of loss of membrane potential on neuronal damage during the acute phase of SAH. METHODS Twenty-four rats were subjected to SAH by the perforation method. The propagation of depolarization in the brain cortex was examined by using electrodes to monitor 2 direct-current (DC) potentials and obtaining NADH (reduced nicotinamide adenine dinucleotide) fluorescence images while exposing the parietal-temporal cortex to ultraviolet light. Cerebral blood flow (CBF) was monitored in the vicinity of the lateral electrode. Twenty-four hours after onset of SAH, histological damage was evaluated at the DC potential recording sites. RESULTS Changes in DC potentials (n = 48 in total) were sorted into 3 types according to the appearance of ischemic depolarization in the entire hemisphere following induction of SAH. In Type 1 changes (n = 21), ischemic depolarization was not observed during a 1-hour observation period. In Type 2 changes (n = 13), the DC potential demonstrated ischemic depolarization on initiation of SAH and recovered 80% from the maximal DC deflection during a 1-hour observation period (33.3 ± 15.8 minutes). In Type 3 changes (n = 14), the DC potential displayed ischemic depolarization and did not recover during a 1-hour observation period. Histological evaluations at DC potential recording sites showed intact tissue at all sites in the Type 1 group, whereas in the Type 2 and Type 3 groups neuronal damage of varying severity was observed depending on the duration of ischemic depolarization. The duration of depolarization that causes injury to 50% of neurons (P50) was estimated to be 22.4 minutes (95% confidence intervals 17.0-30.3 minutes). CSD was observed in 3 rats at 6 sites in the Type 1 group 5.1 ± 2.2 minutes after initiation of SAH. On NADH fluorescence images CSD was initially observed in the anterior cortex; it propagated through the entire hemisphere in the direction of the occipital cortex at a rate of 3 mm/minute, with repolarization in 2.3 ± 1.2 minutes. DC potential recording sites that had undergone CSD were found to have intact tissue 24 hours later. Compared with depolarization that caused 50% neuronal damage, the duration of CSD was too short to cause histological damage. CONCLUSIONS CSD was successfully visualized using NADH fluorescence. It propagated from the anterior to the posterior cortex along with an increase in CBF. The duration of depolarization in CSD (2.3 ± 1.2 minutes) was far shorter than that causing 50% neuronal damage (22.4 minutes) and was not associated with histological damage in the current experimental setting.

Dissociated recovery between dementia and parkinsonism by transvenous embolization of recurrent dural arteriovenous fistula

Dementia and parkinsonism are rarely observed in dural arteriovenous fistula. Here, we report a case of a 63‐year‐old man with recurrent dural arteriovenous fistula, who developed progressive dementia and parkinsonism as a result of a dural arteriovenous fistula at the torcular herophili. A sinus thrombosis induced the abnormal cortical venous reflux from the isolated straight sinus, resulting in the deep venous congestion of the thalamus and basal ganglia, which led to dementia and parkinsonism. However, the third endovascular embolization ameliorated memory disturbance and apathy with a slight improvement of parkinsonism. Although recoveries from dural arteriovenous fistula‐associated neurological deficits are variable depending on the severity, duration and, furthermore, selective vulnerability of the responsible ischemic lesions, early treatment should be essential for better recovery.

Angioarchitecture of arteriovenous fistulas at the craniocervical junction: a multicenter cohort study of 54 patients

OBJECTIVE The aim of this retrospective multicenter cohort study was to assess the details of the angioarchitecture of arteriovenous fistulas (AVFs) at the craniocervical junction (CCJ) and to determine the associations between the angiographic characteristics and the clinical presentations and outcomes. METHODS The authors analyzed angiographic and clinical data for patients with CCJ AVFs from 20 participating centers that are members of the Japanese Society for Neuroendovascular Therapy (JSNET). Angiographic findings (feeding artery, location of AV shunt, draining vein) and patient data (age, sex, presentation, treatment modality, outcome) were tabulated and stratified based on the angiographic types of the lesions, as diagnosed by a member of the CCJ AVF study group, which consisted of a panel of 6 neurointerventionalists and 1 spine neurosurgeon. RESULTS The study included 54 patients (median age 65 years, interquartile range 61-75 years) with a total of 59 lesions. Five angiographic types were found among the 59 lesions: Type 1, dural AVF (22 [37%] of 59); Type 2, radicular AVF (17 [29%] of 59); Type 3, epidural AVF (EDAVF) with pial feeders (8 [14%] of 59); Type 4, EDAVF (6 [10%] of 59); and Type 5, perimedullary AVF (6 [10%] of 59). In almost all lesions (98%), AV shunts were fed by radiculomeningeal arteries from the vertebral artery that drained into intradural or epidural veins through AV shunts on the dura mater, on the spinal nerves, in the epidural space, or on the spinal cord. In more than half of the lesions (63%), the AV shunts were also fed by a spinal pial artery from the anterior spinal artery (ASA) and/or the lateral spinal artery. The data also showed that the angiographic characteristics associated with hemorrhagic presentations-the most common presentation of the lesions (73%)-were the inclusion of the ASA as a feeder, the presence of aneurysmal dilatation on the feeder, and CCJ AVF Type 2 (radicular AVF). Treatment outcomes differed among the angiographic types of the lesions. CONCLUSIONS Craniocervical junction AVFs commonly present with hemorrhage and are frequently fed by both radiculomeningeal and spinal pial arteries. The AV shunt develops along the C-1 or C-2 nerve roots and can be located on the spinal cord, on the spinal nerves, and/or on the inner or outer surface of the dura mater.

A Case of Traumatic Vertebral Arteriovenous Fistula Treated by Internal Trapping of the Vertebral Artery

BACKGROUND Traumatic vertebral arteriovenous fistula (TVAVF) is an uncommon disease that occurs after traumatic injury. Here we report a case of TVAVF presenting with cervical bruit successfully treated by internal trapping using coils. CASE PRESENTATION A 66-year-old man was transferred to our hospital after falling into a ditch. Initial CT revealed a C2 fracture into the right transverse foramen, and the patient had been treated with conservative management. A vascular abnormality was suspected because the patient exhibited cervical bruit on admission. CT angiography revealed right TVAVF at the V2 segment of the right vertebral artery (VA) near the C2 fracture. Digital subtraction angiography also revealed right TVAVF between the V2 segment of the right VA and the vertebral venous plexus, draining into the right internal jugular vein and the deep cervical vein as well as the intracranial venous system. The fistula was also opacified by retrograde flow from the contralateral VA through the union, while the flow in the basilar artery was antegrade. The patient was diagnosed with TVAVF with large transection of the right VA, and underwent endovascular treatment with internal trapping of the right VA using coils starting distal to the transection and proceeding in a proximal direction. After treatment, the right VAVF and right VA were completely occluded. The patient achieved clinical symptom resolution with no neurological deficits. CONCLUSION Endovascular treatment with internal trapping of the VA using coils is safe and effective against TVAVF.

Perioperative management center (Perio) for neurosurgical patients

Perioperative management is critical for positive neurosurgical outcomes. In order to maintain safe and authentic perioperative management, a perioperative management center (PERIO) was introduced to patients of our Neurosurgery Department beginning in June 2014. PERIO involves a multidisciplinary team consisting of anesthesiologists, dentists/dental hygienists/technicians, nurses, physical therapists, pharmacists, and nutritionists. After neurosurgeons decide on the course of surgery, a preoperative evaluation consisting of blood sampling, electrocardiogram, chest X-ray, and lung function test was performed. The patients then visited the PERIO clinic 7–14 days before surgery. One or two days before surgery, the patients without particular issues enter the hospital and receive a mouth cleaning one day before surgery. After surgery, postoperative support involving eating/swallowing evaluation, rehabilitation, and pain control is provided. The differences in duration from admission to surgery, cancellation of surgery, and postoperative complications between PERIO and non-PERIO groups were examined. Eighty-five patients were enrolled in the PERIO group and 131 patients in the non-PERIO group. The duration from admission to surgery was significantly decreased in the PERIO group (3.6 ± 0.3 days), compared to that in the non-PERIO group (4.7 ± 0.2 days). There was one cancelled surgery in the PERIO group and six in the non-PERIO group. Postoperative complications and the overall hospital stay did not differ between the two groups. The PERIO system decreased the duration from admission to surgery, and it is useful in providing high-quality medical service, although the system should be improved so as not to increase the burden on medical staff.