Katsunori Asai

X-ray Angiography Perfusion Analysis for the Balloon Occlusion Test of the Internal Carotid Artery

BACKGROUND A perfusion study should be performed during the balloon occlusion test (BOT) to prevent ischemic events after therapeutic carotid occlusion. We evaluated the efficacy of X-ray angiography perfusion analysis during the BOT. METHODS Twenty-one consecutive patients who underwent the BOT of the internal carotid artery were included. Patients who had a venous phase delay of less than .5 seconds and a mean stump pressure of more than 50 mm Hg without any neurologic symptoms were considered tolerant, and other patients were considered intolerant. A time-density curve was constructed for each hemisphere using X-ray angiography perfusion software (2D-Perfusion). The mean transit time and area under the curve, which correspond to cerebral blood volume, were calculated from the curve. Differences in these parameters between the occluded and nonoccluded hemispheres and the perfusion index were compared between the tolerant and intolerant groups. RESULTS In the intolerant group, the mean transit time was significantly longer (1.31 ± .72 seconds versus .44 ± .21 seconds, P = .001) and the perfusion index was significantly lower (.72 ± .16 versus .94 ± .08, P = .001) compared with those in the tolerant group. The area under the curve was not different between the groups. CONCLUSIONS Parameters obtained by X-ray angiography perfusion analysis were significantly different between the tolerant and intolerant groups. The X-ray angiography perfusion analysis could be a safe and effective method for assessing ischemic tolerance before therapeutic carotid occlusion.

Effect of coil packing proximal to the dilated segment on postoperative medullary infarction and prognosis following internal trapping for ruptured vertebral artery dissection.

Introduction Medullary infarction is an important complication of internal trapping for vertebral artery dissection. This study investigated risk factors for medullary infarction following internal trapping of ruptured vertebral artery dissection. Methods We retrospectively studied 26 patients with ruptured vertebral artery dissection who underwent endovascular treatment and postoperative magnetic resonance imaging between April 2001 and March 2013. Clinical and radiological findings were analyzed to identify factors associated with postoperative medullary infarction. Results Ten of the 26 patients (38%) showed postoperative lateral medullary infarction on magnetic resonance imaging. Multivariate logistic regression analysis revealed that medullary infarction was independently associated with poor clinical outcome (odds ratio (OR) 17.01; 95% confidence interval (CI) 1.68–436.81; p = 0.032). Univariate analysis identified vertebral artery dissection on the right side and longer length of the entire trapped area as risk factors for postoperative medullary infarction. When the trapped area was divided into three segments (dilated, distal, and proximal segments), proximal segment length, but not dilated segment length, was significantly associated with medullary infarction (OR 1.55 for a 1-mm increase in proximal segment length; 95% CI 1.15–2.63; p = 0.027). Receiver operating characteristic analysis showed that proximal segment length offered a good predictor of the risk of postoperative medullary infarction, with a cut-off value of 5.8 mm (sensitivity 100%; specificity 82.3%). Conclusions Longer length of the trapped area, specifically the segment proximal to the dilated portion, is associated with a higher incidence of medullary infarction following internal trapping, indicating that this complication may be avoidable.

Brachial–Ankle Pulse Wave Velocity as a Predictor of Silent Cerebral Embolism after Carotid Artery Stenting

BACKGROUND In neuroendovascular therapy, the effect of arterial stiffness on postprocedural cerebral thromboembolism is unknown. In this observational study, we examined the relationship between cerebral thromboembolism after carotid artery stenting and arterial stiffness. METHODS From April 2015 to February 2017, we enrolled consecutive patients undergoing scheduled carotid artery stenting in our institution. In all patients, preprocedural brachial-ankle pulse wave velocity was used to assess arterial stiffness, whereas the number of new cerebral ischemic lesions on diffusion-weighted magnetic resonance imaging was assessed after treatment. We also analyzed patient data and details of procedures in patients with carotid artery stenting. RESULTS Twenty-one patients completed the study. The mean brachial-ankle pulse wave velocity was 1879 cm/s. There was no association of cerebral thromboembolisms with age, unstable plaque, protection device, or type of stent. However, the brachial-ankle pulse wave velocity was an independent predictor of cerebral thromboembolisms (P = .0017). CONCLUSIONS Brachial-ankle pulse wave velocity is predictive of silent cerebral embolisms on diffusion-weighted magnetic resonance imaging after carotid artery stenting.

Endovascular and Surgical Treatment of Spinal Dural Arteriovenous Fistulas: Assessment of Post-treatment Clinical Outcome

Spinal dural arteriovenous fistulas (DAVFs) are the most commonly encountered vascular malformation of the spinal cord and a treatable cause of progressive para- or tetraplegia. It is an elusive pathology that tends to be under-diagnosed, due to lack of awareness among clinicians, and affects males more commonly than females, typically between the fifth and eighth decades. Early diagnosis and treatment may significantly improve outcome and prevent permanent disability and even mortality. The purpose of our retrospective, single-center study was to determine the long-term clinical and radiographic outcome of patients who have received endovascular or surgical treatment of a spinal DAVF. In particular, during a 6-year period (2009–2014) 14 patients with a spinal DAVF were treated at our department either surgically (n = 4) or endovascularly (n = 10) with detachable coils and/or glue. There was no recurrence in the follow-up period (mean: 36 months, range 3–60 months) after complete occlusion with the endovascular treatment (n = 9; 90%), while only one patient (10%) had residual flow both post-treatment and at 3-month follow-up. All four surgically treated patients (100%) had no signs of residual DAVF on follow-up magnetic resonance angiography (MRA) and/or angiography (mean follow-up period of 9 months). Since improvement or stabilization of symptoms may be seen even in patients with delayed diagnosis and substantial neurological deficits, either endovascular or surgical treatment is always justified.

Transarterial Sinus Embolization for a Dural Arteriovenous Fistula in a Sinus of the Lesser Sphenoid Wing: A Case Report

Dural arteriovenous fistula (DAVF) in a sinus of the lesser sphenoid wing (SLSW) is rarely reported. Here, we report a case of an isolated SLSW DAVF treated by coils placed into the sinus through the feeding artery. A 68-year-old man was admitted to our hospital with headache. Magnetic resonance images and an angiogram showed a varix in the right middle cranial fossa. A DAVF, consisting of three main feeders and the isolated SLSW, was diagnosed based on the angiogram findings. Retrograde leptomeningeal venous drainage to the deep middle cerebral vein was observed. Given the remarkable extent of cortical venous ectasia together with the presence of headache and right abducens nerve paralysis, endovascular treatment was initiated. A transvenous approach through the right inferior petrosal sinus was not feasible because of difficulty associated with inserting the microcatheter into the SLSW. Thus, we tried a transarterial approach and were able to advance the microcatheter beyond the fistula into the isolated SLSW, through the artery of the foramen rotundum. The isolated sinus and feeding arteries were embolized with coils. The postoperative angiogram showed the total occlusion of the SLSW DAVF. This case demonstrates the feasibility of transarterial sinus packing for an isolated SLSW DAVF.

Direct aspiration first pass technique for a middle cerebral artery occlusion with a hidden aneurysm.

Hidden aneurysms within occluded vessels present a challenge for interventionists because vessel perforation can lead to life-threatening complications. We present a case of middle cerebral artery ischemic stroke, refractory to thrombolysis. A direct aspiration first pass technique (ADAPT) was employed for revascularization. Following thrombectomy, an aneurysm of the occluded vessel was revealed. Despite this, the patient recovered without hemorrhagic complication. ADAPT permits the minimal insertion of endovascular devices and might be a safe procedure when hidden aneurysms are suspected.

Intracranial germinomas in a father and his son.

BackgroundPrimary intracranial germ cell tumors (IGCTs) represent an uncommon category of neoplasms, and familial occurrence is rare. We present the first report of parent-child patients with pathologically confirmed pure germinomas.Case reportA 36-year-old Japanese man presented with diabetes insipidus and hypopituitarism. Magnetic resonance imaging (MRI) revealed a mass lesion in the pituitary stalk, which was diagnosed as a pure germinoma by open craniotomy tumor biopsy. Seven years later, his 13-year-old son also presented with diabetes insipidus. MRI revealed mass lesions in the pituitary stalk and the pineal region. He underwent endoscopic tumor biopsy for the pineal lesion, which was diagnosed as a pure germinoma. Both the father and his son were treated with combined radiochemotherapeutic regimens and achieved complete remission after one to two cycles of chemotherapy.ConclusionAlthough there have been three previous case reports of familial germinoma, all of these involved sibling pairs. The present report represents the first parent-child cases. This type of familial occurrence suggests the possibility that germline mutations may also be involved in the development of IGCTs.

X-ray angiography perfusion imaging with an intra-arterial injection: comparative study with 15O-gas/water positron emission tomography

Background X-ray angiography perfusion (XAP) is a perfusion imaging technique based on conventional DSA. Objective In this study, we aimed to validate parameters derived from XAP by comparing them with 15O-gas/water positron emission tomography (PET), using data from patients with chronic ischemic cerebrovascular disease. Methods 18 consecutive patients were included. XAP was performed with intra-arterial infusion of contrast media, and a time–density curve was constructed for each cerebral hemisphere. From the curves, the relative values of mean transit time (rMTT) and wash-in rate (rWiR) were obtained by dividing the values of the right hemisphere by those of the left hemisphere. These were then compared with the relative values of cerebral blood flow (rCBF) and rMTT calculated from the PET data. Results XAP rWiR correlated strongly with PET rCBF (r=0.86, P<0.0001). rMTT measurements from the two modalities were also strongly correlated (r=0.85, P<0.0001). Bland–Altman analysis revealed a bias of 0.14±0.18 (95% limits of agreement −0.22 to 0.51) for PET rCBF versus XAP rWiR, and 0.016±0.093 (95% limits of agreement −0.17 to 0.20) for rMTT between the two modalities. Conclusions The relative values obtained from XAP were validated across a population of patients with chronic ischemic cerebrovascular disease.

Overlapping stent-assisted coil embolization for a ruptured intracranial vertebral artery dissection

Abstract Ruptured intracranial vertebral artery dissection is a cause of non-traumatic subarachnoid hemorrhage. Urgent intervention should be considered to prevent fatal rebleeding. Endovascular parent artery occlusion, which is the initial treatment of choice, is not suitable for patients with a hypoplastic or occlusive contralateral vertebral artery. We report a case of ruptured vertebral artery dissection, which was successfully treated with double overlapping stent-assisted coiling.

Traumatic arteriovenous fistula of the superficial temporal artery

Traumatic arteriovenous fistula (AVF) of the superficial temporal artery (STA) is rare. We report a case of surgically treated, histopathologically confirmed traumatic AVF of the STA. A 24-year-old male was admitted to our hospital after a traffic accident. Computed tomography scan on admission showed an acute epidural hematoma on the right surface of frontal lobe, which was emergently treated by surgical evacuation. One month later, he was aware of pulsatile tinnitus around the left ear. Digital subtraction angiogram showed an AVF, mainly fed by the left STA. After total removal of the fistula, his tinnitus immediately disappeared. Histopathological examination demonstrated that the artery was connected to the vein through the thin-walled vessels lacking internal elastic lamina and muscularized media, suggesting that the connecting vessels were newly formed.