Monitoring of filter patency during carotid artery stenting using near-infrared spectroscopy with high time-resolution.

We aimed to evaluate the usefulness of a newly developed, near-infrared spectroscopy (NIRS) device for monitoring hemodynamic changes during carotid artery stenting (CAS), as a means to detect filter obstruction due to distal embolism. We evaluated 16 patients with internal carotid artery (ICA) stenosis during the CAS procedure, using a NIRS system that can monitor not only changes in oxygenation of hemoglobin (Hb), but also the fluctuation of oxyhemoglobin (oxy-Hb) synchronized with heartbeat. The NIRS system detected a marked decrease of oxy-Hb and an increase of deoxyhemoglobin (deoxy-Hb) during ICA occlusion in patients without anterior cross circulation (ACC). Patients with ACC showed much smaller changes. The analysis of oxy-Hb fluctuation made it possible to detect occurrence of no-flow in the absence of Hb concentration changes. The amplitude of oxy-Hb fluctuation in the no/slow-flow group was significantly smaller than that in the normal-flow group. Our results indicate that the present high time-resolution NIRS device, which can measure oxy-Hb fluctuation, is superior to conventional NIRS for detecting filter obstruction.

Monitoring of hemodynamic change in patients with carotid artery stenosis during the tilt test using wearable near-infrared spectroscopy.

Transient ischemic attack (TIA) is a major complication in patients with carotid artery stenosis. Patients with severe stenosis sometimes complain of orthostatic dizziness, such as syncope. The purpose of this study was to examine the usefulness of near-infrared spectroscopy (NIRS) for evaluating cerebral circulation in patients with carotid artery stenosis during head-up tilt test (HUTT). Fourteen patients with carotid artery stenosis and nine normal control subjects participated. In addition to blood pressure monitoring, hemoglobin (Hb) values (oxy-Hb, deoxy-Hb, and total Hb) were recorded by a wearable NIRS instrument with a high time resolution during HUTT. Oxy-Hb, which decreased initially when the test table was elevated, subsequently increased in normal volunteers and patients with carotid artery stenosis and did not differ significantly between the two groups. However, the oxy-Hb reduction in the carotid artery stenosis group (-0.02 ± 0.03 a.u.) at 30 s after elevation of the table was significantly larger than in the normal group (0.02 ± 0.02 a.u., P < 0.01). Our results indicate that oxy-Hb reduction in patients with carotid artery stenosis may be related to orthostatic dizziness. We concluded that NIRS monitoring is useful for evaluating cerebral autoregulation in patients with severe carotid artery stenosis.

Endovascular treatment for ruptured vertebral artery dissecting aneurysms at the acute stage.

OBJECTIVE: Ruptured vertebral artery dissecting aneurysms (VADA) should be treated promptly because of the high risk of rebleeding. However, it is difficult to treat dissecting aneurysm during the acute stage using microsurgery because of high intracranial pressure or brain edema. Therefore, endovascular treatment of the ruptured VADA may be a better technique. We retrospectively studied the efficacy and outcome of endovascular treatment of ruptured VADA at the acute stage. METHODS: Ten patients with ruptured VADA received endovascular treatment at the acute stage. Eight patients who had dissecting aneurysms were treated by internal trapping of the dissected segment. We performed stent-assisted coiling (SAC) for a case of VADA in contralateral hypoplastic VA and a case of bilateral dissections, ruptured VADA of the right VA and VA dissection of the left VA. RESULTS: Four patients had good recovery, 3 patients had moderate disability, 2 patients had severe disability, and 1 patient died from initial severe SAH. There was no rebleeding or procedure-related complication. However, one patient who was treated by SAC had ischemic complications post-treatment. CONCLUSION: Endovascular treatment of ruptured VADA in the acute stage appears to be safe and effective.

[Stent-assisted angioplasty using the proximal protection method for intracranial internal carotid artery stenosis].

Percutaneous transluminal angioplasty (PTA) with stenting (PTA/stenting) for intracranial atherosclerotic stenoses is usually performed without any embolic protection devise (EPD). However, we have encountered ischemic complications when performing PTA/stenting without EPD for symptomatic intracranial internal carotid artery stenosis. We report here a case of symptomatic intracranial artery stenosis, which was treated by stenting under proximal protection without ischemic complications. The 54-year-old male was admitted to our hospital complaining of motor weakness. Diffusion-weighted image (DWI) in MRI revealed multiple high intensity lesions in the left frontal and parietal lobe. An angiogram demonstrated 80% stenosis in the C5 portion of the left internal carotid artery. PTA/stenting was performed using an occlusion catheter under proximal protection. The occlusion catheter with balloon was placed in the left internal carotid artery of the cervical segment. The balloon was inflated to intercept blood flow, and a driver stent was placed following PTA. Postoperative angiography demonstrated that the degree of stenosis had decreased to almost 5% after PTA/stenting. The patient did not present other neurological deficits. MRI-DWI did not reveal any ischemic lesions following the treatment. PTA/stenting under proximal protection using an occlusion catheter is a simple technique, and is considered to be effective for intracranial internal carotid stenosis.

[A case of dural arteriovenous fistula mimicking isolated transverse-sigmoid sinus successfully treated via the transvenous route].

A 66-year-old man was admitted to our hospital suffering from a left temporo-occipital intracerebral hematoma with bilateral thin subdural hematomas. Neurological examinations revealed slightly decreased cognitive function. Cerebral angiography demonstrated a left transverse-sigmoid dural arteriovenous fistula (TS-DAVF) with cortical venous reflux. The main feeders of the TS-DAVF consisted of multiple branches of the left occipital artery, and the left affected transverse-sigmoid sinus was occluded at both ends, i.e. the affected sinus was isolated. Transvenous embolization (TVE) was performed under general anesthesia. A contralateral approach failed to reach the affected sinus so that an ipsilateral approach was attempted. Contrast material was injected from the left jugular bulb and the route to the affected sinus was visualized. We succeeded in passing both a microguidewire and a microcatheter through the stenosed proximal sigmoid sinus to the fistula area of the affected sinus. The affected sinus was occluded with multiple platinum coils. Post-treatment angiography revealed disappearance of the cortical venous reflux and improvement of the cerebral perfusion. It is a challenging operation to approach an affected sinus through an occluded sinus. However, some cases of isolated TS-DAVFs have the possibility of being treated by TVE via the occluded sinus similarly to cavernous sinus DAVFs.

[Case of symptomatic epilepsy presenting with focal high intensity on diffusion-weighted image prior to initial convulsive seizure].

It has been reported that high intensity on diffusion-weighted image (DWI) in magnetic reasonance imaging (MRI) accompanying a reduction of the apparent diffusion coefficient (ADC) can be detected at the ictal or postictal stage of epileptic seizure. However, it remains unclear whether such a change results from persisting systemic convulsive seizure or from certain physiological changes such as recurrent epileptic discharge prior to the occurrence of obvious convulsion. We report here a case of symptomatic epilepsy displaying a high intensity area on DWI in MRI before convulsive seizure was initiated. A 64-year-old man was admitted to our hospital due to complaints of dizziness and motor weakness. CT and conventional MRI scans failed to reveal any new lesions except for the scar of a ventricular tube in the right parietal lobe, which had been removed due to shunt infection. The DWI, however, demonstrated an apparent high intensity in the right parietal cortex, and the ADC was significantly reduced as compared to that on the contralateral side. Five days after admission, the patient showed convulsive seizures beginning from the right face and upper extremity which subsequently developed to status epilepticus. Following recovery from the convulsions with administration of anticonvulsants, the high intensity of the right parietal lobe on DWI appeared to be diminished. The present case indicates that the manifestation of a high intensity on DWI concomitant with ADC reduction at the epileptic focus can be readily induced by the occurrence of epileptic discharges before convulsive seizure is evident.