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Biomedical subjects

W Grand

Publications and source records attributed to W Grand.

At least 19 recordsLinked to original sources
PubMed2001

Sinonasal Non-Hodgkin's Lymphoma with Skull Base Involvement.

Non-Hodgkin's lymphoma (NHL) is a rare tumor of the skull base. As the incidence of primary central nervous system (CNS) lymphoma has increased, atypical presentations involving the skull or cranial base exclusively have been reported. In immunocompetent patients with no previous history or predisposing factors, the diagnosis of primary NHL of the skull base may be delayed. We present four cases of nasal and paranasal sinus NHL with both skull base and intracranial involvement in immunocompetent patients. Clinicopathologic correlation suggests that cranial base and intracranial involvement with NHL represents advanced-stage primary sinonasal disease. Surgical biopsy before definitive treatment is recommended. Radiation therapy provides local control; adjuvant chemotherapy after primary radiation therapy may be required for recurrent disease.

Case Reports↗
PubMed2001

Olfaction preservation in anterior cranial base approaches: an anatomic study.

OBJECTIVE: To study the anatomic basis for olfaction-sparing anterior cranial base approaches. METHODS: The medial anterior skull base containing the olfactory unit and delimited by the inner table of the frontal sinus, the lesser wing of the sphenoid bone, and the medial orbital walls was removed from six cadaveric specimens. Histological methods were used to investigate the location, distribution, and depth of penetration of olfactory nerves. Hematoxylin and eosin and Gomori trichrome staining were used to visualize landmarks and architecture. S-100 neurofilament protein immunostaining was used to identify nerve fascicles and axons. In three cadaveric head specimens, olfaction-sparing craniofacial approaches were performed and the excised olfactory units were evaluated histologically. RESULTS: Bundles of olfactory nerves were identified primarily in the nasal septum; relatively fewer bundles could be identified in the middle turbinate. Olfactory nerve endings were identified up to 20 mm below the cribriform plate (range, 7-20 mm). The superior and middle nasal meatus were most innervated; olfactory innervation was virtually absent in the inferior nasal meatus. Histological evaluation of the olfactory unit elevated during olfaction-sparing techniques routinely revealed transection of olfactory nerves that exited the skull base. CONCLUSION: In olfaction-sparing anterior cranial base approaches, the olfactory nerves are inevitably transected. The clinical significance of olfactory nerve transection for postoperative functional recovery of olfaction remains to be analyzed.

Cadaver↗
PubMed2001

Eyebrow incision for combined orbital osteotomy and supraorbital minicraniotomy: application to aneurysms of the anterior circulation. Technical note.

A modification of the supraorbital keyhole approach, the eyebrow incision-minisupraorbital craniotomy with orbital osteotomy, is described. Unique to this approach is a one-piece supraorbital craniotomy, measuring 2.5 x 3.5 cm, that incorporates the orbital rim and roof and the frontal process of the zygomatic bone through an eyebrow incision. The orbital osteotomy facilitates view of the anterior and middle cranial fossa through the operating microscope, as well as the maneuverability of instruments through a small craniotomy. A pericranial flap is elevated with its base at the orbit and used for closure of the frontal sinus, if necessary. The approach was used successfully in elective surgery of 10 aneurysms of the anterior circulation. The mean aneurysm size was 5.9 mm, with a range of 4 to 10 mm. Advantages of this approach include minimal disruption and exposure of normal brain tissue, reduced frontal lobe retraction, and an excellent postoperative cosmetic result. The approach is performed quickly by virtue of a limited skin incision with minimal temporalis muscle dissection and a small bone flap. The neuroendoscope, although helpful at times, is not essential and no special instruments or intraoperative image guidance is required. Relative contraindications include the presence of a large frontal sinus, severe brain edema, and recent subarachnoid hemorrhage. In addition, this approach has not been used for the treatment of giant intracranial aneurysms.

Aged↗
PubMed1999

Stereotactic neurosurgical biopsy is an underutilized modality.

The objective of this study was to ascertain if stereotactic neurosurgical biopsy (SNB) optimizes the therapy of undefined CNS masses. The design was of retrospective treatment and outcome analysis and the setting was a large general hospital. We studied a total of 141 patients with undefined, space-occupying CNS lesions detected between 1991-1997, with whom we used SNB to define the lesions. We sought to correlate empiric and histological diagnostics and their impact on medical management. The stereotactic biopsy produced a diagnostic yield for each patient. Management was altered in 57 cases (40%) due to histology and, of these, malignancy was found in 39. Morbidity was ten asymptomatic hemorrhages on post-biopsy CT scans and two cases of clinical deterioration. Our conclusions were that SNB produces high yield with low morbidity. In the community setting, a wide variety of diagnoses can be made with improvements in medical management. SNB should be employed to guide therapy of CNS lesions where complete excision is not possible or when diagnostic questions arise.

Adolescent↗
PubMed1999

The insular cortex: morphological and vascular anatomic characteristics.

OBJECTIVE: We undertook this anatomic study of the insula to investigate its vasculature, morphological features, and surrounding cortical relationships. METHODS: Under magnification of x2 to x32, 53 formalin-fixed, adult cadaver hemispheres were dissected. Overlying opercular landmarks were identified and used as guides to portions of the deeper insula. RESULTS: The insula has a complex venous system; 50 (94.3%) hemispheres exhibited a combination of superficial and deep venous connections. The venous connections divide the insular cortex into the following three anatomic zones, with some overlap: subapical region (insular pole), anterior lobe, and posterior lobe. Arterial contributions to the insula originated entirely from the middle cerebral artery, predominantly via the superior division. Thirty-six (67.9%) specimens exhibited a dedicated terminal vessel to the insula; in 34 of these (94.4%), this terminal vessel arose from the middle cerebral artery branch to the central sulcus. There was never more than one terminal vessel in each insular cortex. CONCLUSION: Historically, it has been reported that the insula drains primarily via the deep middle cerebral vein (DMCV). We found more complex (typically both superficial and deep) venous connections. In most specimens, the DMCV exhibited a direct venous connection to only a portion of the insular cortex. The deep drainage connections of the insula and the vessels that form the DMCV suggest that the DMCV drains primarily the lateral lenticular veins and secondarily the insula. Arterial contributions to the insula tended to be centered around the central insular sulcus, independent of the location of the middle cerebral artery bifurcation. Although the insular vascular anatomic features showed great variability, the anatomic and structural relationships described in this dissection series should facilitate safe surgical and endovascular interventions.

Adult↗
PubMed1999

Neurosurgery at the State University of New York at Buffalo.

WALLACE HAMBY STARTED the first practice dedicated to neurosurgery in Buffalo in 1933. Several years later, he was able to establish a residency program and became nationally known for his treatments of cerebral aneurysms and arteriovenous malformations. It was up to Louis Bakay to create an academic department within the State University of New York system and to incorporate an active and successful research program. This tradition has been expanded and enriched under the present leadership of L. Nelson Hopkins. The department is now well recognized, has 10 full-time staff members, and performs approximately 2000 procedures annually. There are numerous research opportunities available, at both the resident and fellowship levels.

Curriculum↗
PubMed1999

The anatomy of the brain, by Thomas Willis.

This article reviews the 1681 edition of The Anatomy of the Brain, by Thomas Willis (1621-1675), which was first published in Latin in 1664. Although description of the circulation at the base of the brain is part of this text, the majority of the book is devoted to functional anatomic features of the brain. This is an early attempt by Willis to translate cadaveric brain anatomic features into assigned behavioral and neurophysiological functions. Extensive comparisons are made between "lower" animals and human subjects, emphasizing the differences in their intellects. This unique document ushered in the era of modern neuroanatomy and laid the groundwork for future neuroanatomic and neurophysiological investigations.

Animals↗
PubMed1997

Correlation of endothelin-1 and transforming growth factor beta 1 with malignancy and vascularity in human gliomas.

Because the prominent neovascularization characteristic of high grade primary brain tumors is composed mostly of vascular smooth muscle cells (VSMC), we studied the expression of the potent smooth muscle mitogen endothelin-1 (ET-1) and one of its secretagogues, transforming growth factor beta 1 (TGF-beta 1) in a series of astrocytic tumors. TGF-beta 1 is also of interest due to its known activity as an angiogenic factor. Using immunohistochemical methods, we examined 30 surgical cases: 10 glioblastoma multiforme, 10 anaplastic astrocytomas, and 10 low-grade astrocytomas. Using a monoclonal antibody to TGF-beta 1 and a polyclonal antibody to ET-1, we detected both growth factors in all cases of glioblastoma examined. In cases of anaplastic astrocytoma, 4 tumors were positive for both factors; 2 contained only ET-1; 2 contained only TGF-beta 1; and 2 exhibited no tumor cell immunoreactivity for either factor. In low-grade astrocytoma, 4 of 10 tumors showed weak ET-1 immunoreactivity; 2 of those contained TGF-beta 1 immunopositive tumor astrocytes: 6 tumors were negative for both factors. In all tumors that expressed both factors, serial sections showed that regions of ET-1 immunopositivity also tended to be positive for TGF-beta 1. Endothelial cells within all tumors were positive for ET-1. ET-1 and TGF-beta 1 are present in human astrocytomas and their expression correlates with tumor vascularity and malignancy. These results suggest roles for both ET-1 and TGF-beta 1 in the growth and progressive angiogenesis of the human glioma.

Blood Vessels↗
PubMed1997

Microvascular surgical anatomy of the vertebrobasilar junction.

OBJECTIVE: We examined the pertinent microvascular anatomy of 28 formalin-fixed brains to develop anatomic guidelines for aneurysm surgery in the region of the vertebrobasilar junction. METHODS: Using a surgical microscope, the outer diameters were observed for the following main arteries: vertebral, basilar, posteroinferior cerebellar, and anteroinferior cerebellar. The number of lower brain stem perforating arteries was examined in relation to their course. The distance between the arteries and their perforators was measured with respect to anatomic landmarks. RESULTS: The anatomy of the main arteries was characteristically variable, whereas the anatomy of the perforators was constant, particularly in terms of their numbers and points of penetration into the brain substance. The four major points of entry were the lateral medullary area just caudal to the posterior olivary sulcus, the posterior olivary sulcus, the small lateral fossa at the superior olivary groove, and the foramen cecum. Each of these areas coincides with the origin of common vertebrobasilar aneurysms. CONCLUSION: The anatomy of the main arteries was variable. In contrast, the perforators penetrated the adjoining brain stem at specific locations, regardless of the caliber of the main artery. Despite a small vertebral artery or its major branches, perforators penetrating the brain are significant and may effect the outcome of aneurysm surgery or endovascular procedures.

Adult↗
PubMed1980

Microsurgical anatomy of the proximal middle cerebral artery and the internal carotid artery bifurcation.

Knowledge of the distribution of the perforating branches along the proximal middle cerebral artery and at the internal carotid artery bifurcation is important for the surgeon approaching aneurysms and other lesions in these areas. The microsurgical anatomy of the proximal middle cerebral artery and the internal carotid artery bifurcation was analyzed in 36 fixed hemispheres. The number, size, and location of all perforators along the proximal middle cerebral artery and the internal carotid artery bifurcation were noted. Three distinct patterns of perforators arising from the proximal middle cerebral artery were found. The implications of the anatomical variations in this area are discussed.

Carotid Artery, Internal↗
PubMed1979

Extracranial-intracranial arterial bypass in the treatment of aneurysms of the carotid and middle cerebral arteries.

Eleven patients with lesions of the internal carotid and middle cerebral arteries that could not be treated by direct approach are presented. Major vessel occlusion was chosen as definitive therapy. Prophylactic extracranial-intracranial bypass was employed in an attempt to reduce the incidence of ischemic complications. Emphasis is placed on complications, from which several important lessons were learned. Our best results occurred in patients with carotid artery lesions treated with bypass and immediate internal carotid ligation. We believe this to be an effective and safe mode of therapy in cases in which direct approach is not feasible. The low risk and high potential benefit of prophylactic bypass justifies its use before major vessel occlusion in selected cases.

Adult↗
PubMed1978

A safe technique for the precise localization of carotid-cavernous fistula during balloon obliteration. Technical note.

The authors report a technique to precisely localize a fistulous opening in the carotid artery. The patient is heparinized and a Prolo catheter is introduced into the internal carotid artery and inflated distal to the approximate site of the fistula. Heparinization allows the balloon to be inflated long enough to obtain and analyze high-quality angiography film without fear of thromboembolism generated by the temporary balloon occlusion. Contrast material injected through the Prolo catheter proximal to the balloon reveals a small segment of cavernous carotid artery between the inflated balloon distally and the fistula proximally. The venous structures are now only faintly opacified and cannot obscure the morbid anatomy of the exact fistulous tear in the carotid artery. If the balloon is placed exactly opposite to the site of the fistula, a standing, stagnant column of dye forms a cast of the cavernous, petrous, and cervical carotid artery. Once the fistula is localized with this method, it may be obliterated by any therapeutic means preferred. If the Prolo catheter is used for intraluminal occlusion, then a transfemoral contralateral carotid angiogram is done before the heparin is reversed to confirm that the balloon has not been placed proxial to the fistula.

Arteriovenous Fistula↗
PubMed1977

Demonstration of transventricular CSF absorption by computerized tomography.

Four cases are presented of marked periventricular oedema associated with hydrocephalus on CT scan. In one of the patients oedema, as well as the hydrocephalus, subsided after successful re-establishment of CSF absorption. The most likely explanation of the periventricular oedema is increased absorption of CSF by periventricular brain tissue.

Aged↗