Transarterial intravenous coil embolization of dural arteriovenous fistula involving the superior sagittal sinus.

BACKGROUND: We report a rare case of traumatic dural arteriovenous fistula involving the superior sagittal sinus successfully treated by transarterial intravenous coil embolization. CASE PRESENTATION: A 38-year-old woman presented with tension headache. She had a past history of severe head injury at the age of three. Computed tomography scanning showed a heterogenous low-density area in the right frontal lobe, and magnetic resonance imaging demonstrated abnormal vascular structures in the same area. Angiography revealed a dural arteriovenous fistula involving the lateral wall of the fully patent superior sagittal sinus. The fistula was fed by scalp, meningeal, and cortical arteries, and drained into a cortical vein leading to the superior sagittal sinus. Femoral transarterial intravenous embolization with microcoils completely occluded the dural arteriovenous fistula. CONCLUSION: Severe head injury may lead to asymptomatic dural arteriovenous fistulas after a long time. Transarterial intravenous coil embolization can be effective in the treatment of dural arteriovenous fistulas involving the superior sagittal sinus.

Measurement of the intracranial arterial wedge pressure in cases of acute cerebral arterial occlusion to determine the indication of intraarterial thrombolytic therapy.

SUMMARY: Wedge pressure of the occluded major cerebral artery (distal pressure beyond the occlusion) was measured to estimate the residual cerebral blood flow in thirteen patients with acute ischemic stroke. There existed the relationship that patients with higher wedge pressure tolerated longer ischemic insults than those with lower wedge pressure. Wedge pressure is measured with minimum time loss before starting thrombolytic therapy and may be a good indicator to estimate the brain tissue reversibility.

Endovascular Surgery for Internal Carotid Stenoses. Results of PTA vs. Stenting.

SUMMARY: This paper will overview our results of endovascular therapy (PTA or stenting) for cervical ICA stenosis and discuss the advantages and disadvantages of each treatment. 60 cases with 62 lesions were treated with PTA 68 times, while 36 cases with 37 lesions were treated with stenting 37 times. A total of 99 lesions were treated with PTA or stenting 105 times. In the PTA group arterial stenosis improved from 76.4% to 21%. In the stent group the stenosis improved from 82.3% to 8.3%. The morbidity rate was 2/60 (3.3%) in PTA group, although two cases had minor neurological deficits, while in stent treated group, morbidity rate was 1/36 (2.8%), although it showed one major neurological deficit. Mortality was 0% in each group. The restenosis rate in PTA group was 15/58 (26%), while it was 0/20 (0%) in stent treated group. Stenting brings significant reduction of stenosis and reduces the rate of restenosis compared to PTA. However, stenting has its own disadvantages such as hypotension and distal kinks when deployed in tortuous ICA stenosis.

Endovascular treatment for internal carotid stenoses. long-term follow-up results and overall complications.

Seventy four cases of internal carotid stenoses greater than 60% were treated by PTA and/or stenting 86 times. Sixty one cases of cervical ICA stenosis were treated 71 times. 11 cases of high cervical - intracranial ICA stenosis were treated 13 times. Two cases of ICA dissection were treated by stent deployment. Stenotic ratio reduced from 79% to 29% in cervical ICA stenosis and 71 % to 32% in high cervical to intracranial ICA stenosis in average. Morbidity related to PTA and/or stenting was 2/74 (2.7%) and mortality was 0%. One was an ischemic complication and the other was a hemorrhagic complication due to hyperper fusion. Restenosis (stenosis greater than 70%) rate was 32%. Asymptomatic cerebral embolism were found in three cases (4.2%) on angiogram immediately after PTA and/or stenting. The complication rate related to PTA and/stenting was low but asymptomatic emboli were found in three cases. Considering these results, the indication for PTA and/stenting should be restricted to patients with high risk group, such as cases with high medical risks or difficult CEA cases, if appropriate protective systems for cerebral emboli were not available.

[When do strokes occur?--analysis of diurnal variation and activity during the onset].

The diurnal variation and activity during the onset of stroke were examined in more than 700 consecutive patients. 304 cases with hypertensive intracerebral hemorrhage (HIH), 214 cases with subarachnoid hemorrhage (SAH) and 201 cases with obstructive cerebrovascular disease (OCVD) were investigated about the time of onset. Concerning the activity during the onset, 296 cases with HIH, 215 cases with SAH and 198 cases with OCVD were examined. HIH occurred frequently between 1500-1800 hours, 0600-0900 hours and 1800-2100 hours. SAH occurred frequently between 0900-1200 hours, 1500-1800 hours and 1800-2100 hours. Both HIH and SAH were least likely to occur between 0000-0300 hours. OCVD exhibited a small peak incidence between 0900-1200 hours, but there were no differences between the groups for the other time periods. Both HIH and SAH were likely to occur frequently in the lavatory, while bathing and during meals. HIH also occurred frequently during physical work, while SAH occurred as frequently during mental work or housework as during hard physical labor. OCVD commonly occurred during sleep or relaxation. The relationship between diurnal variation in stroke and the circadian variation of blood pressure is discussed. The incidence of all three types of strokes during work was higher in the non-aged group (patients under 66 years) than in the aged group (patients over 66 years). HIH and SAH occurred associated with alcohol consumption more frequently in the non-aged group than in the aged group. It is likely that the difference of the time and of the activity during the onset between aged group and non-aged group reflects the difference of life-style between aged and non-aged people.

The effect of endovascular therapy for cerebral arterial spasm, its limitation and pitfalls.

PURPOSE: The effect of endovascular treatment for vasospasm was investigated by analysing the results of patients treated in Wakayama City in 1994. MATERIALS AND METHODS: Ninety nine patients with ruptured cerebral aneurysms, who survived more than one week and were treated in Wakayama City in 1994, were studied. Twenty five patients caused symptomatic vasospasm and 25 were treated by endovascular therapy, percutaneous transluminal angioplasty (PTA) and/or intra-arterial papaverine infusion (IAP). PTA was performed for proximal vasospasm which located in the main arterial trunk, such as ICA, M1, BA (n = 3). IAP was chosen for distal vasospasm which located mainly in the M2, A1, A2 (n = 12). PTA and/or IAP was performed for diffuse vasospasm which located in proximal and distal arteries (n = 10). RESULTS: In the proximal vasospasm group, all patients were good to moderately disabled on the Glasgow outcome scale (GOS). In the distal vasospasm group, 8 patients were good to moderately disabled, and 4 patients were severely disabled. The overall results were as follows: 17 (68%), good to moderately disabled, 4 (16%), severely disabled, 4 (16%), dead. The morbidity and mortality rate was 8/25 (32%) in symptomatic spasm group. CONCLUSION: PTA was very effective especially for proximal vasospasm, but IAP was not always effective for distal or diffuse vasospasm. Diffuse vasospasm revealed a high mortality rate in spite of the endovascular therapy.

[Newly developed blocking balloon catheter for PTA of internal carotid artery].

We have developed a new blocking balloon system for percutaneous transluminal angioplasty (PTA) of the internal carotid artery (ICA). A latex balloon (BALT) is attached on the top of a Superselector infusion-type catheter (TORAY) which is used as a blocking balloon catheter. It can be navigated into the distal part of the ICA under torque control as well as flow control by withdrawing the core wire. Our PTA procedure is as follows, 1) insert the sheath catheter 8-9 F in size, 2) insert the PTA balloon catheter (Accent balloon, Cook) with a blocking balloon catheter through the sheath catheter, 3) navigate the blocking balloon into the distal part of the ICA, 4) introduce the PTA balloon to the stenotic portion after occlusion of the distal ICA by the blocking balloon, 5) PTA, 6) wash the lumen of the ICA with saline, 7) deflate the blocking balloon and withdraw the system. We performed PTA for 5 ICA lesions in 4 cases and got successful dilatations for all of them without complications. Our blocking balloon system is useful for performing the PTA of the ICA safely.

Influence of regional cerebral blood flow on event-related potential (P300).

The relationships between event-related potential (P300), higher brain functions, and regional cerebral blood flow (rCBF) were examined in 31 neurosurgical patients. The P300 latency, evaluated by an acoustic "odd-ball" paradigm, was normal in 14 and prolonged in 17 patients. Fourteen of 17 prolonged P300 patients had reduced rCBF in the right cerebral hemisphere, especially the frontal lobe and/or thalamus. There was a significant inverse relationship between P300 latency and laterality index (rt rCBF/lt rCBF) in the frontal lobe. Prolonged P300 patients revealed significant abnormalities in psychological tests compared to normal P300 patients. There were significant inverse relationships between the P300 latency and "orientation" and "memory" test scores. Decreased rCBF in the right cerebral hemisphere, especially the frontal lobe and/or thalamus, is associated with prolonged P300 latency, suggesting that the right cerebral hemisphere is important in human cognitive processes.

A method for quantitative measurement of cerebral vascular permeability using X-ray CT and iodinated contrast medium.

Cerebral vascular permeability is an important consideration in treatment for intracranial tumours. We have developed a new method to measure the cerebral vascular permeability quantitatively using a conventional X-ray CT scanner and iodinated contrast medium. We have already applied our method in 50 cases of intracranial tumour and 5 cases, which establish the methodology, are demonstrated. Dynamic CT scanning of a section including the tumour and the superior sagittal sinus was performed over 40 min after bolus injection of contrast medium, and 25 images were acquired. Our theoretical model of contrast enhancement was applied to analyse time-density curves, and the following parameters were obtained: Ki (inward flux constant), Kb (backward flux constant), Vp (vascular plasma volume), and lambda (extracellular fluid space volume). Furthermore, functional maps were generated from parameters for each pixel. Changes in intra-arterial iodine concentration, required in our model, were measured from CT numbers in the superior sagittal sinus. We have investigated several aspects of our method. Histological findings in surgical specimens of intracranial tumours agreed well with the parameters obtained by our method. Vp was verified quantitatively by single photon emission computed tomography. Our method was shown to be reproducible. These results show that the parameters are useful for assessing tumours and in planning chemotherapy. Our method, which employs no special equipment, is readily available at any institution.

Local blood flow changes in malignant brain tumours under induced hypertension.

Changes in tumour blood flow under an induced hypertensive state were examined in malignant brain tumours to know if the precondition for the effectiveness of induced hypertensive chemotherapy--relative increase in tumour blood flow--are fulfilled. Tumour blood flow was measured under both a resting and an induced hypertensive state in 12 patients with various malignant brain tumours (6 gliomas, 6 metastatic brain tumours) using xenon-enhanced computed tomography. The blood pressure was elevated 40% above the systemic blood pressure of the resting state by the infusion of angiotensin II. Tumour blood flow increased 30% on average above the normal brain tissue blood flow after the induction of an induced hypertensive state (p < 0.05). The tumour blood flow increased in 11 cases of malignant tumours, but decreased in one case with massive brain oedema after induced hypertension. The increase in blood flow was higher in hypervascular tumours and less in hypovascular tumours. Therefore, induced hypertensive chemotherapy probably will be more effective in hypervascular malignant brain tumours with small mass effects.

Dynamic computed tomography for the evaluation of cerebrovascular disease.

Dynamic computed tomography (DCT) was evaluated as a diagnostic indicator for chronic supratentorial ischemia in 50 cases with or without minor neurological deficits. Peak height (PH, the maximum value of the gamma fitted curve), peak time (PT, the time to PH from the start of DCT), transit time (TT, the time between the first and second inflection points of the gamma fitted curve), and their functional maps were analyzed. Cerebral angiography was then performed in all cases to identify stenotic or occlusive vascular lesions in major cerebral arteries. DCT clearly detected 12 of 13 occlusions of the internal carotid artery (ICA) or middle cerebral artery (MCA), although one ICA occlusion was masked by the contralateral MCA occlusion. However, DCT detected only severe ICA or MCA stenosis (more than 90%). Probably, stenotic lesions of less than 90% did not cause detectable hemodynamic compromise. DCT using PH, PT, and TT functional maps is a useful diagnostic method for hemodynamic changes in ischemic cerebrovascular disease, although bilateral lesions and less stenotic lesions (less than 90%) are difficult to detect.

Assessment of risk of carotid occlusion with balloon Matas testing and dynamic computed tomography.

Temporary occlusion of the internal carotid artery with a balloon catheter (balloon Matas test) and simultaneous dynamic computerized tomography scanning (DCT) were performed to determine the tolerance of permanent carotid occlusion in eight cerebral aneurysm and two carotid-cavernous fistula (CCF) cases, in whom internal carotid occlusion might be necessary during operation or as a choice of treatment. All patients were evaluated by mean transit time (MTT), especially % transit time (MTT of the occluded side x 100/MTT of the control side). In six patients, % transit time (%TT) was less than 155 and no neurological signs appeared after permanent internal carotid occlusion. Neurological deficit appeared when mean arterial blood pressure was 80, and disappeared when mean arterial blood pressure was 100 during the balloon Matas test in a case whose %TT was 200. Neurological deficit appeared several seconds after the balloon Matas test in a case whose %TT was 250. The critical %TT value to cause symptomatic ischaemia was 200 from our results. Therefore, it is necessary to undertake treatment such as bypass surgery for the patients whose %TT is near 200, even if the balloon Matas test was negative.