Yong Kwang Tu

Evaluation of Intracranial and Extracranial Carotid Steno-Occlusive Diseases in Taiwan Chinese Patients With MR Angiography Preliminary Experience

BACKGROUND AND PURPOSE We attempted to evaluate the location of vascular lesions in cases of cerebrovascular steno-occlusive diseases in Chinese persons living in Taiwan. METHODS With three-dimensional time-of-flight magnetic resonance angiography (MRA) as a screening tool, 108 symptomatic patients with cerebrovascular steno-occlusive diseases were examined. Cardioembolic disease and cerebral hemorrhage cases were excluded. The degrees of stenosis of bilateral cervical carotid arteries and their major intracranial tributaries were recorded. They were categorized as nonsignificant stenosis (0% to 49%), significant stenosis (50% to 99%), and total occlusion. RESULTS Our data revealed that 32.4% of the cases were normal in either cervical carotid arteries or their intracranial tributaries. In 24.1% of the cases, significant extracranial carotid stenosis or occlusion was the only finding on MRA. In 25.9% of the cases, only significant intracranial-tributary stenosis was found. In 17.6% of them, significant lesions were found in both extracranial and intracranial carotid artery tributaries. CONCLUSIONS A racial difference between Chinese and white patients in location of lesion in cerebrovascular steno-occlusive diseases was confirmed. About one third of symptomatic Chinese patients living in Taiwan showed small-vessel disease. Approximately 24% of patients had only extracranial carotid disease, and about 26% had only intracranial carotid tributary disease. We need a larger series of patients to confirm these findings. However, MRA might be a good screening tool for steno-occlusive cerebrovascular disease, especially in persons of a race with more intracranial carotid disease, such as the Chinese.

Is surgical therapy needed for unruptured arteriovenous malformations

A conservative attitude toward unruptured arteriovenous malformations (AVMs) has been based on the belief that surgical resection is too risky and that their natural history is benign. We have operated on 103 patients with a cerebral AVM. In the 49 patients with unruptured AVMs, there was no mortality, and the morbidity was 14.2%. Similarly, low surgical morbidity has been reported from several centers during the last few years. The chance of hemorrhage for both ruptured and unruptured AVMs is about 3% per year, and the combined morbidity and mortality of each hemorrhage is at least 40%. All patients with an AVM should be individually considered for possible surgical resection, whether or not they have bled.

Cervicocranial arterial dissection: experience of 73 patients in a single center.

BACKGROUND Arterial dissection involving cervicocranial arteries usually results in ischemia or SAH. This study correlated the clinical manifestations, image characteristics, and outcome of arterial dissection and compared the differences between arterial dissection of anterior and posterior circulation at our institute. METHODS Clinical symptoms and neuroradiologic findings were retrospectively analyzed in 73 patients (6-75 years old) who had a spontaneous arterial dissection of cervicocranial vessels verified by angiography or MRI. Twenty-four cases of ACAD and 49 cases of PCAD were included in this study. RESULTS The leading presentation of arterial dissection of ACAD group was ischemic stroke (79.2%), and that of posterior circulation was SAH (44.9%), followed by ischemic stroke (42.8%). In the ACAD group, the extracranial ICA was more commonly involved (62.5%), with long segmental narrowing the most common angiographic finding. In the PCAD group, the intracranial VA was more commonly involved (81.6%), with alternating narrowing and dilatation the leading angiographic picture. All the cases presenting with ischemic stroke or headache were conservatively treated with anticoagulants or antiplatelets, except for one treated with intra-arterial thrombolysis for thromboembolism in basilar artery at an early stage. One of them died of progressed brainstem infarct in spite of anticoagulation therapy. All the others reached improved or stable clinical condition. Eighteen cases were treated by surgical or endovascular intervention. None of them had rebleeding. Of the 5 patients with SAH due to dissecting lumens without treatment, 2 died of rebleeding. CONCLUSIONS Ischemia is the predominant presentation of ACAD; and PCAD has similar occurrence of SAH and ischemia. Intracranial arterial dissection is not uncommon; and it should be kept in the list of differential diagnosis of young stroke. Aggressive treatment of arterial dissection presenting with SAH should be considered; otherwise, rebleeding may occur.

Direct surgery of carotid cavernous fistulae and dural arteriovenous malformations of the cavernous sinus

OBJECTIVE To save the patency of the internal carotid artery (ICA) during the treatment of carotid cavernous fistulae or cavernous sinus dural arteriovenous malformations, direct surgery of the cavernous sinus after failure of endovascular treatment was attempted in this study. METHODS A total of 78 patients with carotid cavernous fistulae or cavernous sinus dural arteriovenous malformations were treated. Obliteration of the fistulous rent and preservation of the ICA were the therapeutic goals. All patients, except one in whom acute bleeding occurred, received endovascular treatment as the first treatment. In 18 (23.4%) of these 77 patients, it was not possible to obliterate the fistulous rents without sacrificing the ICAs. The 18 patients and the 1 patient with acute bleeding underwent direct surgery to open the cavernous sinus. RESULTS Various methods, including suturing or clipping the fistulae, sealing the fistulae with fascia and acrylate glue, and packing the cavernous sinus were applied. In each of three complicated cases, the cavernous segment of the ICA was trapped and an intracranial bypass from the petrous segment to the supraclinoid segment was performed. There was nor mortality, and the most common morbidity was transient oculomotor palsy, which occurred in eight patients. Follow-up angiography revealed that the ICAs or bypass grafts were thrombosed in 5 of the 19 patients who had undergone surgery. CONCLUSION In this series, the overall ICA patency rate of patients who underwent embolization and surgery was 94%, and the obliteration rate of the fistulae was 100%. Direct surgery of the cavernous sinus as a complimentary treatment of embolization can increase the preservation rate of the ICA.

Decompressive craniectomy as the primary surgical intervention for hemorrhagic contusion

The standard surgical treatment of hemorrhagic cerebral contusion is craniotomy with evacuation of the focal lesion. We assessed the safety and feasibility of performing decompressive craniectomy and duraplasty as the primary surgical intervention in this group of patients. Fifty-four consecutive patients with Glasgow Coma Scale (GCS) scores of less than or equal to 8, a frontal or temporal hemorrhagic contusion greater than 20 cm(3) in volume, and a midline shift of at least 5 mm or cisternal compression on computer tomography (CT) scan were studied. Sixteen (29.7%) underwent traditional craniotomy with hematoma evacuation, and 38 (70.4%) underwent craniectomy as the primary surgical treatment. Mortality, reoperation rate, Glasgow Outcome Scale-Extended (GOSE) scores, and length of stay in both the acute care and rehabilitation phase were compared between these two groups. Mortality (13.2% vs. 25.0%) and reoperation rate (7.9% vs. 37.5%) were lower in the craniectomy group, whereas the length of stay in both the acute care setting and the rehabilitation phase were similar between these two groups. The craniectomy group also had better GOSE score (5.55 vs. 3.56) at 6 months. Decompressive craniectomy is safe and effective as the primary surgical intervention for treatment of hemorrhagic contusion. This study also suggests that patient with hemorrhagic contusion can possibly have better outcome after craniectomy than other subgroup of patients with severe traumatic brain injury.

Transarterial embolisation of complex cavernous sinus dural arteriovenous fistulae with low-concentration cyanoacrylate

Abstract We report the effectiveness of low-concentration n-butyl-2-cyanoacrylate (NBCA)-Lipiodol-tungsten mixture (10–15 %) in the management of patients with aggressive or recurrent complex cavernous dural arteriovenous fistulae (CSDAVF). We treated five patients with complex CSDAVF with a low concentration of an NBCA-Lipiodol-tungsten mixture after catheterisation of the feeding arteries arising from the external carotid artery. Three had a recurrent CSDAVF after transarterial particulate embolisation. Three refused transvenous treatment or could not be treated in this way; two patients had also feeding dural branches of the internal carotid artery. All patients had complete resolution of symptoms and signs within a month of the procedure. No definite neurological complication was found during follow-up ranging from 12 to 36 months. Transarterial embolisation with low-concentration cyanoacrylate appears to be an effective alternative management of aggressive or recurrent CSDAVF.

Early endoscope-assisted hematoma evacuation in patients with supratentorial intracerebral hemorrhage: case selection, surgical technique, and long-term results

OBJECT Currently, the effectiveness of minimally invasive evacuation of intracerebral hemorrhage (ICH) utilizing the endoscopic method is uncertain and the technique is considered investigational. The authors analyzed their experience with this method in terms of case selection, surgical technique, and long-term results. METHODS The authors performed a retrospective analysis of the clinical and radiographic data obtained in 68 patients treated with endoscope-assisted ICH evacuation. Rebleeding, morbidity, and mortality were recorded as primary end points. Hematoma evacuation rate was calculated by comparing the pre- and postoperative CT scans. Glasgow Coma Scale scores and scores on the extended Glasgow Outcome Scale (GOSE) were recorded at the 6-month postoperative follow-up. The technical aspect of this report explains details of the procedure, the instruments that are used, the methods for hemostasis, and the role of hemostatic agents in the management of intraoperative hemorrhage. The pertinent literature was reviewed and summarized. RESULTS All surgeries were performed within 12 hours of ictus, and 84% of the surgeries were performed within 4 hours. The mortality rate was 5.9%, and surgery-related morbidity occurred in 3 cases (4.4%). The hematoma evacuation rate was 93% overall-96% in the putaminal group, 86% in the thalamic group, and 98% in the subcortical group. The rebleeding rate was 1.5%. The mean operative time was 85 minutes, and the average blood loss was 56 ml. The mean GOSE score was 4.9 at 6-month follow-up. The authors acknowledge the limitations of these preliminary results in a small number of patients. CONCLUSIONS The data suggest that early endoscope-assisted ICH evacuation is safe and effective in the management of supratentorial ICH. The rebleeding, morbidity, and mortality rates are low compared with rates reported in the literature for the traditional craniotomy method. This study also showed that early and complete evacuation of ICH may lead to improved outcomes in selected patients. However, the safety and efficacy of endoscope-assisted ICH evacuation should be further investigated in a large, prospective, randomized trial.

Acute effects of isovolemic hemodilution with crystalloids in a canine model of focal cerebral ischemia

We used 44 splenectomized dogs to study the effects of isovolemic hemodilution with a crystalloid solution. The dogs were randomly divided into a hemodilution and a control group. In each group, 17 dogs were subjected to 6 hours of internal carotid and middle cerebral artery occlusion, and five dogs received sham operations. Isovolemic hemodilution by phlebotomy and Ringers lactate infusion was performed 30 minutes after arterial occlusion and resulted in an average hematocrit of 32-33%. Hemodilution significantly reduced viscosity, fibrinogen and total protein concentrations, and plasma oncotic pressure. Systemic arterial blood pressure and pulmonary wedge pressure decreased slightly with hemodilution, but central venous pressure and pulmonary arterial pressure did not change significantly. There was a similar decrease in cardiac index in both hemodiluted and control dogs, which may have been due to the effects of barbiturate anesthesia. Intracranial pressure increased significantly with time in all dogs subjected to arterial occlusion, but this increase was significantly more severe in the hemodiluted dogs. Specific gravity, measured just after the dogs were killed, 6 hours after hemodilution, was significantly lower in the white matter and basal ganglia of the left (ischemic) hemisphere in hemodiluted dogs than in controls. Regional cerebral blood flow decreased significantly in the left hemisphere after arterial occlusion. This decrease was almost completely reversed by hemodilution except in the basal ganglia, where the increase in edema caused by hemodilution was the greatest.

Epidemiological study of moyamoya disease in Taiwan.

From January 1978 to December 1995, 92 cases of Moyamoya disease were collected from seven major medical centers in Taiwan. The data gave an annual incidence rate of 0.048 per 100,000 population. There were 40 males and 52 females and the ages ranged from 2 to 62 years with the peak incidence in the 31-40 year age group (23 cases). Cerebral infarction occurred in 20 out of 24 juvenile patients (83%), and in 24 out of 68 adult patients (35%). The difference was statistically significant. Haemorrhagic stroke was more frequent in adult patients. Computed tomographic scans following stroke showed cerebral infarction in 44 cases, ventricular haemorrhage in 26 cases, intracerebral haemorrhage in 14 cases and pure subarachnoid haemorrhage in eight. The most frequent initial symptom was motor disturbance (59%), followed by headache (49%) and impaired consciousness (35%). This survey showed an incidence rate much lower than that in Japan, but comparable with those in other Oriental countries and higher than those in Western countries. The male-to-female ratio once differed considerably from that of the Japanese series, but from the present study is now quite similar.

Early clinical characteristics of patients with persistent post-concussion symptoms: A prospective study

Primary objective: To identify the early clinical features of patients with mild traumatic brain injury (mTBI) that are predictive of the presence of persistent post-concussion symptoms (PPCS). Research design: A prospective study was conducted at a level I trauma centre. Methods and procedures: One hundred and eighty mTBI patients participated in this study. The post-concussion symptoms (PCS) were evaluated with a PCS checklist. All patients were examined at 1, 2 and 8 weeks post-injury. The chi-square test was used to evaluate the associations of each PCS and the logistic regression was used to identify potential predictors of mTBI patients who might suffer from PPCS. Main outcomes and results: Less than one-tenth of the mTBI patients examined complained of PPCS at 2 months after head trauma. Patients with PPCS are more likely to suffer from intracranial lesions. Moreover, clinical symptoms at 1 and 2 weeks post-injury, especially physical ones including headache, dizziness and fatigue, were reported significantly more often by patients with PPCS. Conclusions: This study showed that early clinical symptoms and intracranial lesions may be strongly associated with the presence of PPCS. Thus, those specific characteristics may be used as early indicators of long-term difficulties.