PubMed Health⌕ Search

Biomedical subjects

V B Graves

Publications and source records attributed to V B Graves.

14 recordsLinked to original sources
PubMed1991

Delayed visual loss due to trauma of the internal carotid artery.

The group of six patients in this study experienced delayed visual loss following head trauma. Visual loss occurred from 1 day to 13 years after the initial injury. All patients suffered indirect trauma to the internal carotid artery resulting in formation of either an aneurysm or pseudoaneurysm or a carotid-cavernous fistula. Review of the radiologic and clinical findings was performed in six patients. The diagnosis was established by computed tomography, magnetic resonance imaging, and angiography. All patients had follow-up clinical evaluation and imaging studies. Treatment by neurosurgical or interventional neuroradiologic procedures resulted in significant visual improvement in five patients. Different pathophysiologic mechanisms could be correlated with the delayed visual loss produced by the two types of lesions. The pathologic changes associated with the aneurysms/pseudoaneurysms included direct compression of optic nerves and/or chiasm and intracranial hematoma. A carotid-cavernous fistula caused delayed visual loss by either hematoma at the orbital apex or compression of the chiasm and/or optic nerves by saccular dilatation of the cavernous sinus. The delayed onset of decreased vision following head trauma should alert the physician to the possibility of a traumatic aneurysm/pseudoaneurysm or a carotid-cavernous fistula. Different neuro-ophthalmologic symptoms can usually be correlated with the pathologic changes demonstrated by neuroimaging procedures.

Adolescent↗
PubMed1990

Intracranial arteriovenous malformations. Current imaging and treatment.

Patients with intracranial arteriovenous malformations (AVM) can expect significant mortality (15% to 20%) and morbidity (20% to 30%) over a 15-year to 20-year period. Recent advances in interventional neuroradiology, neurosurgery, neuroanesthesia, and stereotactic radiotherapy provide the opportunity to obliterate many of these lesions that were untreatable previously. The overall risk from treatment is estimated to be less than 50% that associated with untreated AVMs. For these reasons, it is important for the diagnostic radiologist to understand the diagnosis, natural history, treatment choices, and risks associated with patients with intracranial AVMs.

Craniotomy↗
PubMed1977

Dissecting aneurysm of intracranial arteries.

The authors present a case of the sudden onset of hemiplegia in an eight-year-old boy secondary to a dissecting aneurysm of the right internal carotid artery and middle cerebral artery.

Aortic Dissection↗
PubMedDate not supplied

A new guidewire with kink-resistant core and low-friction coating.

A new guidewire constructed from kink-resistant titanium-nickel alloy, polyurethane, and hydrophilic polymer is described. We have used this wire in 119 angiographic and 49 interventional procedures without complications. In numerous applications, it offers significant advantages over other guidewires. It is particularly helpful for angiography and interventional procedures requiring catheterization through markedly tortuous vessels, tight stenoses, or occlusions.

Alloys↗
PubMedDate not supplied

MR imaging of spinal pachymeningitis.

We report a case with pathologic correlation that demonstrates the magnetic resonance imaging characteristics of spinal pachymeningitis. Contrast enhanced T1-weighted images clearly demonstrated the thickened contrast enhancing meninges in a patient with progressive radiculomyelopathy who had both clinical and imaging evidence of progression of disease.

Aged↗
PubMedDate not supplied

Flow dynamics of lateral carotid artery aneurysms and their effects on coils and balloons: an experimental study in dogs.

PURPOSE: To investigate the hemodynamic characteristics of lateral carotid artery aneurysms in a canine model and to determine their influence on coils and balloons. MATERIALS AND METHODS: Forty aneurysms were created in fourteen dogs and their hemodynamic characteristics and influence on coils and balloons were evaluated with angiography and color Doppler pre- and postplacement. Twenty aneurysms were treated with coils, eight with balloons, and 12 aneurysms served as controls. RESULTS: The aneurysms demonstrated three distinct zones of flow: 1) an inflow zone entering at the distal aspect of the aneurysm ostium, 2) an outflow zone exiting at the proximal ostium, and 3) a central slow flow vortex. The inflow zone is a determining factor in the placement and stability of coils and balloons placed within the aneurysm and in the thrombosis of an aneurysm. The force of the inflow is considerable and can alter the shape of coils and displace both coils and balloons positioned within the aneurysm. CONCLUSIONS: Coils and balloons need to be of shapes and sizes that do not conform to the inflow and outflow zones. Filling the aneurysm and blocking or displacing the inflow zone can produce thrombosis of an aneurysm with preservation of the parent artery.

Angioplasty, Balloon↗
PubMedDate not supplied

Aneurysm hemodynamics: an experimental study.

PURPOSE: To study the flow of blood in aneurysms. METHODS: A canine model was used to study the hemodynamics of lateral, bifurcation, and terminal aneurysms with angiography and color Doppler techniques. FINDINGS: Flow within experimental aneurysms, although not laminar, is seldom if ever turbulent, but rather is highly predictable, varying primarily according to the relationship of the aneurysm to its parent artery. CONCLUSIONS: These studies support earlier in vitro work and provide further evidence that not all aneurysms share similar stresses. A more complete understanding of these hemodynamic features will be useful in the establishment of criteria that allow recognition of those aneurysms that are more or less likely to rupture, to grow, or to thrombose.

Aneurysm↗
PubMedDate not supplied

Treatment of carotid artery aneurysms with platinum coils: an experimental study in dogs.

The objectives of this study were to investigate the consistency, patency, and natural history of a vein graft canine aneurysm model and to determine the effectiveness of various coil designs on inducing aneurysm thrombosis. Twenty-one sacculuslike aneurysms were created in mongrel dogs by anastomosing a vein pouch to the common carotid artery. The model produced wide-neck aneurysms with 100% patency. The canine vein graft aneurysm provided an excellent model for the evaluation of endovascular devices. Three types of specially designed platinum coils were placed in the aneurysms: those with simple curves, those with complex curves, and those with flower petal curves and silk fibers. These coils were placed by the endovascular route by means of microcatheters. Flower petal coils with silk fibers were effective in producing thrombosis of the aneurysms, suggesting that coils of the appropriate design may be useful in the endovascular treatment of aneurysms. The other coil designs evaluated, those with simple and complex curves without silk fibers, demonstrated insufficient thrombogenicity and spatial stability.

Animals↗
PubMedDate not supplied

Biocompatibility of 1-French polyethylene catheters used in interventional neuroradiology procedures: a study with rats and dogs.

This study was designed to investigate the thrombogenicity, inflammatory response, and endothelial response to the presence of sterilized, 1-French polyethylene catheters implanted into the arterial system and subcutaneous tissues of 18 rats and two dogs. At time periods ranging from 1 week to 6 months, repeat angiography was done, the animals sacrificed, and the tissues containing the catheter removed for histologic study. In the subcutaneous tissues the catheter became encased in a very thin (less than 0.5 mm) coating of fibrous tissue with no evidence of inflammation. In large vessels, the catheter at all time periods appeared identical both angiographically and histologically to that at the time of implantation. In small to medium-sized vessels a slight increase in vessel size (25% increase in diameter of the rat iliac) was observed angiographically. On histologic evaluation, there was evidence of myointimal hypertrophy, which was asymmetrically placed, centered around the position of the catheter. There was no evidence of thrombi or of incorporation of the catheter itself into the hypertrophic tissue. In dogs and rats, an implanted 1-French polyethylene catheter is well tolerated: the animals showed no evidence of thrombotic, thromboembolic, or inflammatory complications. Myointimal hypertrophy was observed in small to medium-sized arteries, which is of unknown significance.

Animals↗