In this review I describe my method of carotid endarterectomy with synthetic patch angioplasty. The use of Hemashield patch angioplasty is relatively new in my practice, and since I have adopted it I feel it has reduced or eliminated early restenosis and acute postoperative occlusion. The technique is simple and straightforward, and does not require any special preparation of the patch material. The patch is stronger and safer than saphenous vein. The other steps of the endarterectomy are unchanged, and the same suture can be used for patch placement. I also describe here a new commercial shunt which I have developed and which I feel is an improvement over the shunts I previously used. I place an indwelling shunt selectively, if electroencephalography criteria indicate that a shunt is needed. In my series this occurs in 15% of cases, increasing to 25% in patients with contralateral carotid artery occlusion. The overall stroke rate in my carotid artery series is 1.8% at present.
The relationship between traumatic extra-axial hematomas and cerebral atrophy was investigated in 42 adult patients aged between 15 and 50 years who required removal of extra-axial hematomas. These patients were followed up by serial computed tomography for more than 6 months after head injury. Nine of these patients developed cerebral atrophy. Their Glasgow Coma Scale score on admission was 6.4 ± 2.8 (mean ± SD). The score of the patients without cerebral atrophy was 9.6 ± 3.3 (p < 0.01). These patients had three extradural and six subdural hematomas. All patients with cerebral atrophy had cerebral swelling postoperatively, more prominent in the hemisphere ipsilateral to the hematoma in seven patients. This swelling was associated with global hypodensity and persisted for 10.4 ± 2.9 days. The severity of cerebral atrophy was more prominent in the hemisphere ipsilateral to the hematoma in five of these seven patients. Extra-axial hematoma in patients with severe head injury can induce hemispheric cerebral atrophy in the underlying cerebral hemisphere.
The effect of glycerol on blood flow in tumoral and peritumoral tissue was measured in 32 patients with brain tumor, 17 gliomas and 15 meningiomas. Blood flow before and after the administration of glycerol was measured by stable xenon-enhanced computed tomography. The tumor part of glioma was significantly hypoperfused. In contrast, the tumor part of meningioma was significantly hyperperfused. Peritumoral edema of both glioma and meningioma was hypoperfused. After the administration of glycerol, blood flow increased in all regions except for the tumor part of glioma. Vascular responses to glycerol may be different in these two tumor types. The steal phenomena of blood flow might occur in cases of glioma.
Staged transsphenoidal surgery was performed in seven patients with nonfunctioning pituitary adenomas with suprasellar extension. Remnant adenomas were present in a suprasellar position after complete removal of the intrasellar tumor, and did not descend into the sella because of the fibrous nature in five patients or fibrous nature and dumbbell shape in two. Magnetic resonance images were obtained every 2 weeks following initial surgery. The suprasellar residual adenomas descended into the sella within 2 months in six patients and 1.5 months in one patient. A second transsphenoidal operation was performed 2 months following the initial procedure in four patients, 3 months in one, and 5 months in two. In six of the seven patients, extensive tumor removal was achieved safely and easily by the staged approach. Patients were followed up over 6 to 58 months (mean ± SD 24.7 ± 18.9 months). There were no major surgical complications or recurrence of tumor on follow-up images. Our postoperative imaging studies and surgical results demonstrated that staged transsphenoidal surgery is an effective and safe treatment for fibrous nonfunctioning pituitary adenomas with suprasellar extension.
A 7-year-old boy presented with recurrent meningitis after head trauma. Coronal computed tomography (CT) revealed prolapse of the intracranial soft tissue into the right ethmoidal sinus, leading to the diagnosis of right frontal skull base fracture. Three-dimensional CT with bone windows provided a lifelike image of the fracture lateral to the right olfactory groove. This image was most useful in the preoperative planning of the repair surgery.
A 39-year-old male presented with a putaminal hemorrhage. Angiography disclosed the incidental findings of association of basilar artery fenestration and persistent primitive trigeminal artery. This is the first report of this association of congenital anomalies of the cerebral vessels.
A 60-year-old male presented with radiation-induced left carotid artery stenosis. Carotid endarterectomy was performed successfully without postoperative deficits. Carotid endarterectomy is the therapeutic management of choice for these lesions.
A 45-year-old male presented with sudden onset of severe headache. Computed tomography and magnetic resonance imaging demonstrated an irregularly enhanced suprasellar mass with intratumoral and subarachnoid hemorrhage. The mass was removed in two operations. Histological examination of the tumor revealed pilocytic astrocytoma. The relatively rich vascularity and perivascular tumor cell proliferation observed in this benign lesion were probably the causes of this extremely rare association.
A 69-year-old female presented with a meningioma of the pineal region manifesting as gait disturbance and mental dysfunction. Magnetic resonance imaging revealed a homogeneously well-enhanced circumscribed round mass of about 5 cm in diameter in the pineal region. Angiography demonstrated that the tumor was fed mainly by the bilateral middle meningeal arteries (MMAs), and preoperative intravascular embolization was performed through the bilateral MMAs using estrogen-alcohol and polyvinyl acetate. The tumor was very soft and easily totally resected via the right occipital transtentorial approach. Preoperative embolization is a very useful technique to facilitate removal of deep-seated tumors.
A 37-year-old male presented with a very rare cystic meningioma in the trigone of the left lateral ventricle. Neurological examination revealed mild conduction aphasia and right hemisensory disturbance. Computed tomography and magnetic resonance imaging showed a solid, enhancing tumor in the left trigone which had multiple cystic components located anteriorly and superiorly. The tumor was totally resected via a parietal, transventricular approach. Histological examination revealed an atypical meningioma with cellular pleomorphism and prominent nucleoli. Both the solid component and the cyst wall consisted of tumor cells.
A 70-year-old female presented with symptoms of right-sided trigeminal neuralgia. Computed tomography showed a high-density mass in the prepontine cistern without enhancement. Magnetic resonance (MR) imaging showed the mass as heterogeneous with variable but largely high-signal intensity on T1-weighted images and low-signal intensity on T2-weighted images. At surgery, the lesion was found to be an epidermoid cyst filled with old blood and lipid debris. The high-signal intensity on the T1-weighted images may reflect lipid or methemoglobin with the low intensity on T2-weighted images representing hemosiderin. Most intracranial epidermoid cysts appear as low-intensity lesions on T1weighted images and high-signal intensity on T2-weighted images. Typical MR imaging findings are neither specific for nor constant with epidermoid cysts, requiring critical differential diagnosis.