PubMed Health⌕ Search

Biomedical subjects

F K Gregorius

Publications and source records attributed to F K Gregorius.

At least 19 recordsLinked to original sources
PubMed1983

Surgical exposure of the high cervical carotid artery: experimental study and review.

Difficulty in gaining access to the high cervical internal carotid artery (ICA) has thus far prevented effective operation for intimal repair and treatment of aneurysms at this level. Mobilization of the angle of the mandible by means of mandibular osteotomies considerably improves exposure to the high cervical ICA. This procedure has been performed in rhesus monkeys and in human cadavers. In monkeys, retromandibular external carotid artery-ICA anastomoses were carried out with no problems (neurological, wound healing, or other). This new technique should be considered for the management of some high cervical ICA lesions, particularly those occurring after closed cervical trauma.

Animals↗
PubMed1978

Intimal dissection of the superficial temporal artery.

Three patients who underwent superficial temporal-middle cerebral artery anastomosis demonstrated a dissection of the intima of the superficial temporal artery at operation. The fact that this abnormality had not been appreciated previously in surgical series and that it and other anatomical variants may account for "technical failures" of anastomoses is elucidated. The authors describe their successful technique for suturing the intimal flap.

Cerebral Arteries↗
PubMed1976

Cervical spondylotic radiculopathy and myelopathy. A long-term follow-up study.

The natural history of cervical spondylotic myelopathy in a series of 55 patients resulted in a moderate to severe disability during a mean period of 45 months. Results of operation for myelopathy indicated improvement in one group that was maintained for a mean of 85 months. In another group, progressive worsening occurred after operation, or late worsening occurred, in some instances as long as 8 to 12 years after improvement and plateau. Patients with cervical spondylotic radiculopathy tended to be separated from those with myelopathy with respect to presentation, symptom complex, and operative result. Results of operation for radiculopathy were consistently good. A worsened disability postoperatively for patients with cervical spondylotic myelopathy was associated with the preoperative symptom of sphincter disturbance and the sign of lower extremity weakness. Change in hand movement after operation for myelopathy and change in distance walking ability were not correlated with numerous preoperative factors. A trend of improvement in disability following anterior interbody fusion and a tendency to worsen in disability following all varities of laminectomy were significant.

Female↗
PubMed1976

Pathologenesis of hematogenous bacterial meningitis in rabbits.

The authors present data obtained from a series of 27 rabbits studied following intracarotid injection of saline, brain-heart infusion broth, aerobic, or anaerobic bacteria. These data support the hypothesis that injections of cultures of both aerobic and anaerobic organisms by way of the carotid artery disrupts the blood-brain barrier over the cerebral convexities within 15 minutes; however, the inflammatory response and bacterial proliferation occur much more rapidly in the ventricular system. Within 3 hours,the barrier over the convexities is intact, but leukocytes and organisms may be seen in the long cilia of the aqeuductal region. A relative failure of leucotaxis over the convexities of the brain is the most likely explanation of these preliminary findings in this experimental model.

Animals↗
PubMed1976

Cryosurgery in removal of orbital tumors.

Two cases in which medially placed retro-orbital tumors were approached transfrontally have been presented. The computerized tomographic scanner was important in the localization of both lesions. Although of different histologic types, both tumors were friable and vascular. This friability and vascularity would have caused severe difficulties in removal had it not been for the facility with which a cryoprobe froze and grasped tumor tissue. The importance of this instrument, previously unemphasized, has been pointed out.

Aged↗
PubMed1976

Neurologic complications of gas myelography by the lumbar route.

Gas myelography is not a new technique, but its acceptance in neuroradiologic diagnosis has been relatively recent. Previously reported series have emphasized the benign nature of this technique and the lack of significant accompanying complications. From a series of 174 gas myelograms performed during a four-year period, two reports are presented wherein transient exacerbation of neurologic deficit followed exchange of cerebrospinal fluid and gas under pressure by the lumbar route. One patient with cervical spondylotic myelopathy experienced an increase in paresis, while another was found to have marked fasciculations. Speculation regarding possible mechanisms involved with these complications is presented. It is suggested that exchange of cerebrospinal fluid and gas under pressure via the lumbar route be used with caution in those patients with compromised cervical spinal cords.

Female↗
PubMed1976

Scanning electron microscopic observations of the common carotid artery of the rat. III. Heparin effect on platelets.

After administration of high systemic doses of heparin verified by assay, common carotid arteries in the rat were divided and sutured. Scanning electron microscope observations of endothelial surfaces showed a decrease in platelet adhesion, as well as a reduction in the adherence of other circulatory blood elements when compared to controls. This is the first report indicating the in vivo effect of high dose systemic heparin on platelets.

Animals↗
PubMed1976

In vivo evaluation of nylon suture material by the scanning electron microscope.

Sixty common carotid arteries in rats were divided and anastomosed with four needles that differed in suture to needle diameter ratios. Scanning electron microscopic observations of the suture revealed endothelial bridges with associated fibrin, platelets and leukocytes arising from needle holes to adhere to the sutures within two hours of anastomosis. These earliest reported observations of suture endothelialization merit further investigation regarding the possibility of an arterial thrombosis occurring after suture.

Animals↗
PubMed1976

Positional vertigo with cerebellar astrocytoma.

The authors present two surgically verified cases of cerebellar astrocytoma extending into the fourth ventricular floor. Each patient presented with positional vertigo, and electronystagmography revealed positional nystagmus indicative of a central lesion. The findings in these cases emphasize the need of looking for positional nystagmus in patients with suspected posterior fossa lesions.

Adolescent↗
PubMed1975

Loss and recovery of vision with suprasellar meningiomas.

Central visual acuity losses were documented in a group of 23 patients with surgically and histologically verified suprasellar meningiomas. The pattern demonstrated was that of acute, gradual or fluctuating loss in one eye, followed by later loss of central acuity in the other eye. Both optic nerves and chiasm were invariably involved either by stretching or compression. Neither preoperative field abnormalities nor central acuity deficits could be correlated with the anatomical location of the tumor, nor could postoperative changes in vision be correlated with tumor size. Lengthy duration of acuity loss and severe visual deficit did not preclude postoperative recovery of vision. Improvement in sight most frequently occurred within the first several weeks after operation, and further return of vision was not noted after 1 year.

Blindness↗
PubMed1975

Scanning electron microscopic observations of common carotid artery endothelium in the rat. I. Crater artifacts.

Changes in the endothelial surface of the common carotid artery of the Sprague-Dawley rat were observed by scanning electron microscopy after vessels were removed prior to sacrifice or after gluteraldehyde cardiac perfusion. Rates were classified according to whether the vessels was 1) untouched prior to removal, 2) dissected and observed for a period of time, and 3) clamped and observed. Changes consisted of small 1-6 micron craters as well as smooth or cross-striated endothelial ridges or folds. Clamped arteries appeared to exhibit more frequent craters. In contrast, vessels removed prior to death and briefly washed with saline exhibited craters different morphologically from those vessels perfused with gluteraldehyde. Background endothelial folds also differed from the gluteraldehyde-perfused group, exhibiting a cobblestoned or breaded appearance with distorted endothelial bridges. This supports the suggestion of Nelson that premortem perfusion of heart and ascending aorta with gluteraldehyde is necessary to reduce artifact in arterial endothelial structures.

Animals↗
PubMed1975

Scanning electron microscopic observations of common carotid artery endothelium in the rat. II. Sutured arteries.

Scanning electron microscopic findings in 26 rats with sutured 1 to 1.2 mm segments of carotid artery indicate a difference in morphological changes beneath clamped areas and areas 2 to 3 mm adjacent to the suture line. Craters similar to those observed in control specimens were seen beneath clamped sites without significant platelet aggregation or platelet adherence to the endothelial wall. In contrast, areas adjacent to the suture line exhibited a pattern of fibrin and platelet adherence to the vessel endothelial wall. These changes appeared to be consistent after one to four hours of observation in most animals. Sutures, although attracting some platelets, did not exhibit platelet and fibrin adherence as marked as that of the adjacent endothelial wall.

Animals↗