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Biomedical subjects

M Dujovny

Publications and source records attributed to M Dujovny.

At least 127 records · Page 7Linked to original sources
PubMed1990

Use of experimental aneurysms to evaluate wrapping materials.

Experimental venous pouch aneurysms in rats were wrapped with muscle, bovine collagen, muslin, cotton, or polyvinyl alcohol. The rats were killed 6 or 12 weeks later, and the aneurysms were compared with control aneurysms. Bovine collagen and muscle were reabsorbed and the aneurysms were similar to the control group. Cotton, muslin, and polyvinyl alcohol caused fibrosis around the aneurysm. However, giant aneurysms were found in the muslin and polyvinyl alcohol group. Cotton appears to be the most suitable material for wrapping aneurysms. The experimental venous pouch aneurysm model in rats can be used to evaluate wrapping materials.

Animals↗
PubMed1990

Intracranial vertebral endarterectomy.

Intracranial vertebral endarterectomy was performed on six patients with vertebrobasilar insufficiency in whom medical therapy failed. The patients underwent operations for stenotic plaque in the intracranial vertebral artery with the opposite vertebral artery being occluded, hypoplastic, or severely stenosed. In four of the patients, the stenosis was mainly proximal to the posterior inferior cerebellar artery (PICA). In this group, after endarterectomy, the vertebral artery was patent in two patients, and their symptoms resolved; in one patient the endarterectomy occluded, but the patient's symptoms improved; and in one patient the endarterectomy was unsuccessful, and he continued to have symptoms. In one patient, the plaque was at the origin of the PICA. The operation appeared technically to be successful, but the patient developed a cerebellar infarction and died. In one patient the stenosis was distal to the PICA. During endarterectomy, the plaque was found to invade the posterior wall of the vertebral artery. The vertebral artery was ligated, and the patient developed a Wallenburg syndrome. The results of superficial temporal artery to superior cerebellar artery anastomosis are better than those for intracranial vertebral endarterectomy for patients with symptomatic intracranial vertebral artery stenosis. The use of intracranial vertebral endarterectomy should be limited to patients who have disabling symptoms despite medical therapy, a focal lesion proximal to the PICA, and a patent posterior circulation collateral or bypass.

Aged↗
PubMed1990

Image-guided stereotactic centered craniotomy and laser resection of solid intracranial lesions.

A technique in which solid intracranial lesions are removed using computerized image processing under stereotactic conditions is described. A specially developed carbon fiber ring holder compatible with most image studies is used as a reference system. Intraoperatively it affords freedom of patient positioning and unobstructed access to any site of the head. Four position alternatives of the aiming device allow the removal of lesions from any location. For superficial lesions located near eloquent areas, a 'centered' craniotomy is performed, usually under local anesthesia, and removal is performed using loupe magnification, bipolar coagulation ultrasonic aspiration of the Nd:YAG laser fiber in the contact or noncontact technique. In deep-seated lesions, a surgical 'corridor' is established and kept by means of retractors adapted for use with the stereotactic apparatus. Microsurgical techniques and the CO2 laser are used in solid lesions; in vascular lesions, bipolar coagulation or the ND:YAG laser can be used. Centered craniotomy allows the precise localization, enhancement, three-dimensional orientation and removal of lesions with minimal trauma to the surrounding brain. The technique has been applied in 78 cases where the extreme accuracy of the technique, benign postoperative course and short hospitalization have been impressive.

Angiography, Digital Subtraction↗
PubMed1990

Posterior inferior to posterior inferior cerebellar artery anastomosis combined with trapping for vertebral artery aneurysm. Case report.

A case is presented in which a giant intracranial vertebral artery aneurysm gave rise to an associated ipsilateral posterior inferior cerebellar artery (PICA) from its waist. Proximal vertebral artery ligation at C-1 was achieved. The aneurysm filled from the opposite vertebrobasilar junction. Direct intracranial trapping of the right vertebral aneurysm was followed by successful anastomosis of the proximally sectioned right PICA to the adjacent left PICA in an end-to-end fashion.

Adult↗
PubMed1989

Tumour recurrence vs radionecrosis: an indication for multitrajectory serial stereotactic biopsies.

External RT has been proved to be an important adjuvant to surgery in the treatment of malignant glioma. It has also been demonstrated, that its effect on survival is dose-dependent, although accompanied by a higher morbidity. Intents to localize the field of high dose RT to the tumour area have been performed with the aim to spare damage of the normal brain tissue. Between August 1983 to December 1987, 40 patients with malignant astrocytoma (16 GM, 24 AA) underwent high dose localized hyperfractionated external RT after surgical resection. Patients received 57.6 Gy to the tumour and oedema area associated with a boost localized to the tumour of 7.4, 14.4 or 24 Gy. In the follow-up, 16 patients died with evidence of increase in size of lesion diagnosed by CT/MRI. Since July 1987, 12 patients with recurrence or increase on size of CT/MRI lesion have undergone multitrajectory serial stereotactic biopsies. From the biopsies 8 patients were histologically diagnosed was compatible with radionecrosis. From the 4 recurrences, 2 patients were treated with 125I implants and 1 with new resection. Patients with radionecrosis were treated with corticoides and diuretics, obtaining partial or complete remission of symptoms and decrease in size of CT lesion. Undoubtly, Multiplanar/3D multitrajectory serial stereotactic biopsies play a major role in the follow-up of these patients, and accurate diagnosis need to be established for further treatment therapy. The question remains if these localized boost should be replaced by 3D Multiplanar stereotactic interstitial radiotherapy boost after surgery and conventional radiotherapy.

Astrocytoma↗
PubMed1989

Transposition of image-defined trajectories into arc-quadrant centered stereotactic systems.

A methodology and computer program used for transposition of image-defined trajectories into stereotactic space is presented. Arc-quadrant centered stereotactic frames (Leksell, modified by us Komai) are based on the principle of aiming a target point from any entry of a formed sphere of known radius. Frames adapted isocentrically to CT gantry and parallel to the scanning plane allow interactive selection of targets and trajectories based on multiplanar reformatted images. The mathematical fundaments to calculate angle A in the coronal plane and angle B in the saggital plane based on the geometrical configuration of arc-quadrant centered stereotactic devices are presented.

Brain Diseases↗
PubMed1989

Balloon embolization of nontraumatic vertebral arteriovenous fistulae in children.

Two children, aged 4 and 8 years, with nontraumatic extracranial vertebral arteriovenous fistula are described. Under general anesthesia and with fluoroscopic guidance, using a percutaneous endovascular technique, latex detachable balloons were used to successfully occlude the fistulae. The patients were monitored with somatosensory and auditory evoked potentials and kept hypotensive for 24 hours. Immediate and follow-up angiography 1 year later showed obliteration of the fistula in both patients. The management of this rare condition is discussed.

Arteriovenous Fistula↗
PubMed1989

Microsurgical anatomy of the venous drainage into the superior sagittal sinus.

Ten unfixed human brains were examined under an operating microscope to evaluate the feasibility of reimplanting the parasagittal veins into the superior sagittal sinus. On average, there were 6.5 veins draining the surface of each hemisphere in the anterior frontal region, 3 veins draining each posterior frontal region, 4 veins draining each parietal region, and 1 vein draining each occipital region. The veins were most frequently 0.1 to 1.0 mm in diameter, but were as large as 3.0 mm in the anterior frontal and occipital regions, 3.5 mm in the parietal region, and 5.0 mm in the posterior frontal region. The mean vein length between the superior sagittal sinus and the first lateral attachment was 3.0 to 7.4 mm; individual veins were as long as 30.0 mm. The 20 hemispheres contained a total of 5 veins in the anterior frontal region, 7 veins in the posterior frontal region, and 8 veins in the parietal region that appeared to have an adequate diameter and length for microsurgical reimplantation into the superior sagittal sinus. The superior sagittal sinus had a mean width of 4.3 mm and depth of 3.6 mm in the midanterior frontal region and enlarged to a mean width of 9.9 mm and depth of 6.8 mm in the midoccipital region. In all sites, the sinus appeared to be structurally compatible with vein reimplantation. In 3 cases, veins 2.8 to 4.6 mm in diameter were reimplanted microsurgically into the sinus; in each case, the anastomosis was technically satisfactory and patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Surgical alternatives in the treatment of cavernous sinus aneurysms.

Direct surgery on aneurysms in the cavernous sinus is a formidable technical procedure. The intimate relationship of the intracavernous carotid artery to the venous structures and to the cranial nerves make surgical access difficult at best. Thirty-two of 356 aneurysm patients presented with symptomatic aneurysms originating from the intracavernous internal carotid artery. Twenty-one patients had aneurysms contained entirely within the cavernous sinus, and in 11 others the aneurysms arose within the cavernous sinus and extended into the subarachnoid space. Of the purely intracavernous aneurysms there were five small aneurysms (less than 25 mm) and 16 giant (greater than or equal to 25 mm) aneurysms. Fifteen patients with purely intracavernous lesions had a superior orbital fissure syndrome, and six had a variety of other symptoms. Of 11 patients with subarachnoid extension, five had a subarachnoid hemorrhage (Grade I or II), five had ipsilateral visual loss, and one had periorbital pain. The aneurysms were treated as follows: Group 1 received progressive ligation of the internal carotid artery in the neck with a Selverstone clamp and a surface superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis (purely intracavernous in nine, and with subarachnoid extension in one); Group 2 underwent trapping of the internal carotid artery and a deep STA-MCA anastomosis (purely intracavernous in seven); and Group 3 had direct clipping of the aneurysm (purely intracavernous in five, and with subarachnoid extension in 10). The cavernous sinus was entered directly through its roof by a pterional craniotomy with radical removal of the optic canal, lesser sphenoid wing, and lateral and superior orbital walls. Proximal control of the internal carotid artery was obtained through a cervical incision. Two patients in Group 1 developed transient neurological deficits, which resolved. Two patients in Group 2 developed a cerebral infarction, one of whom died; in both of these patients, the anastomosis was completed after the internal carotid artery occlusion. Two patients in Group 3 progressed from marked visual loss to blindness of the same side, and one developed an intraventricular hemorrhage during induction of anesthesia and died without surgery. It is proposed that a direct approach to symptomatic aneurysms in the cavernous sinus is the best initial alternative. When this approach is not feasible, a trapping procedure preceded by a high-flow extracranial-intracranial anastomosis may be considered. Although the authors have been able to clip aneurysms of various sizes, this has not been possible in all patients. Further work is needed in this area.

Cavernous Sinus↗
PubMed1988

Surgical management of aneurysms in the cavernous sinus.

A series of 32 patients with aneurysms in the cavernous sinus region is presented. All of them have been operated upon through an intradural pterional approach and the aneurysms directly attacked. Only in 6 patients was the complete dissection of the internal carotid artery and of the aneurysm impossible because of the size of the aneurysms. In these cases the aneurysm has been traped by ligation of the internal carotid artery in the neck and its supraclinoid course and at the same time and extracranial intracranial anastomosis performed. One patient died from massive cerebral infarction after a trapping procedure and another died from a transoperative haemorrhage; another two developed a moderate hemiparesis which resolved within the first six postoperative weeks, and in two patients a preoperative severe visual impairment progressed postoperatively to complete visual loss. All others had a complete resolution of their preoperative symptoms and remained well. The advantages and disadvantages of the different approaches to intracavernous carotid artery aneurysms are discussed and the related literature reviewed.

Cavernous Sinus↗
PubMed1988

Cerebrovascular occlusive disease in children: a survey.

Eight cases of stroke in children treated with surgery are reported. Four of the patients had Moya-moya disease and presented with TIA. They were treated by surgically creating collaterals through the STA-MCA bypass, encephalomyosyangiosis and encephalomyoarteriosynangiosis operations. Three patients with traumatic or idiopathic carotid artery stenosis or occlusion presented with TIA and were treated with STA-MCA bypass. One patient with idiopathic carotid artery stenosis presented with a complaint of a continuous swishing noise in the ear and had a STA-MCA bypass followed by carotid artery ligation. Although stroke in children is usually secondary to systemic disease, there is a group of children with surgically treatable disease who need to be identified and treated. The potential benefit of surgery may depend on the promptness with which a definitive diagnosis is reached.

Adolescent↗
PubMed1988

Three-quarter prone approach to the pineal-tentorial region.

A three-quarter prone, operative approach to the pineal region is described: the three-quarter prone, operated-side-down position. This approach avoids the disadvantages of the approaches from other directions to this region and provides a comfortable position for the surgeon and assistant, minimal retraction of the parietal-occipital lobe, and access to the third ventricle, pineal region, midbrain, and superior vermis.

Brain Neoplasms↗
PubMed1988

Freeze-fracture cytochemistry of cholesterol content in neuronal plasma membrane following cerebral ischaemia.

Minor changes on the neuronal perikaryon cytoplasm and large alterations in neuronal processes have been demonstrated with transmission electron microscopy after 60 minutes of focal and selective cerebral ischaemia. The distribution of cholesterol in neuronal plasma membrane and perikarya plasmalemma of normal and ischaemic caudate nucleus was investigated with the polyene antibiotic filipin, a morphological probe for membrane cholesterol domains in freeze-fracture replicas. After filipin incubation of prefixed vibratome slices, filipin-cholesterol complexes appeared as 20-30 proturberances and pits on P- and E-faces. Distinct patterns of filipin-cholesterol complexes were found in non-ischaemic and ischaemic neuronal membrane. The filipin-treated specimens showed a 35-40% drop in cholesterol content in the neuronal plasmalemma one hour after cerebral ischaemia.

Animals↗
PubMed1988

Anomalies and variations of the middle cerebral artery: a microanatomical study.

The microvascular anatomy of the main trunk and divisions of the middle cerebral artery was studied in 104 unfixed brain hemispheres injected with polyester resin and dissected under the operating microscope. The following anomalies and variations of the middle cerebral artery were found: fenestration (1 case; 1%), located on the first 4 mm of the main trunk of the middle cerebral artery; duplication (1 case; 1%), with vessels arising from the internal carotid artery; accessory middle cerebral artery (2 cases; 2%), originating on the A1 segment of the anterior cerebral artery; single-trunk type of middle cerebral artery (4 cases; 4%), with no division of its main trunk; quadrifurcation (4 cases; 4%), in which the main trunk of the middle cerebral artery divided into four secondary trunks. The clinical implications of these anatomical findings are discussed, and photographs of representative specimens illustrate the anomalies.

Cerebral Arteries↗
PubMed1987

Microanatomy of the premamillary artery.

The premamillary artery was studied in 50 unfixed human brain hemispheres (51 vessels were found) which were injected with polyester resin and dissected under the operating microscope. In one hemisphere there was duplication of the premamillary artery. There were premamillary arteries arising from the posterior communicating artery (PCoA) in 49 cases and from the posterior cerebral artery in the remaining two. The arteries originated from the superior and lateral surfaces of the PCoA and coursed superiorly, laterally, and posteriorly to enter a triangular perforated space limited by the mamillary body and tuber cinereum medially, the optic tract anterolaterally, and the cerebral peduncle posterolaterally. This space is called the paramedian perforated substance. The premamillary artery had an outer diameter of 0.6 +/- 0.2 mm on the right side and 0.6 +/- 0.1 mm on the left. The length of the premamillary artery was 12.0 +/- 2.0 mm on the right side and 12.7 +/- 1.9 mm on the left. Sixty-three percent of the premamillary arteries gave off branches that supplied the cerebral peduncles, optic tract, and paramedian perforated space. The clinical importance of these anatomical data in the symptomatology and management of vascular and neoplastic diseases in and around the posterior circle of Willis is discussed.

Cerebral Arteries↗
PubMed1987

Geriatric neurosurgery.

The "elderly," aged 65 and over, represent a rapidly growing proportion of the American population. Their percentage among the neurosurgical admissions at Henry Ford Hospital increased from 14.4% in 1978 to 22.4% in 1984. Occlusive cerebrovascular disease was the most frequent pathology seen, representing 40% of the population studied. Spinal degenerative myeloradiculopathy represented 14%, tumors 7%, trauma 5.4%, and intracranial hematomas represented 4% of the population. Vascular anomalies represented 3.3% of the patient group, with almost the same number of patients presenting with intracranial hemorrhage. The percentage of patients who were surgically treated was 58%. Mortality was 6.5%, with only 2.5% of the patients requiring special-care-facility placement following release from the hospital. An older group, aged 85 and over, represented 4% of our geriatric population. In the age 85+ group, occlusive cerebrovascular disease was the leading pathology (18% of the population), followed by subdural hematomas (15%), spinal degenerative myeloradiculopathy (11.6%), trigeminal neuralgias (7%), hydrocephalus (4%), vascular anomalies (4%), and tumors (4%). Patients in the age 85+ group were surgically treated in 41% of the cases, with a mortality of less than 10%. In the past, older age (greater than 65 years) was believed to be a contraindication to surgery, however, the increased life expectancy, number, and health of this population made reconsideration of this arbitrary age limit essential. We feel that age alone is not a barrier to proper neurosurgical treatment when other risk factors are adequately managed.

Age Factors↗
PubMed1987

Adrenergic innervation of human middle cerebral artery. Ultrastructural observations.

The innervation of the human middle cerebral artery is studied with transmission electron microscopy using the chromaffin reaction technique. Adrenergic nerve fibers and related terminals, with granular electrodense neurotransmitter vesicles, are confined to the tunica adventitia-tunica media transitional zone and the outer layers of the media. These findings may indicate the presence of an adrenergic vasoconstrictor system for circulation control in the human middle cerebral artery.

Cerebral Arteries↗