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Biomedical subjects

W T Koos

Publications and source records attributed to W T Koos.

At least 19 recordsLinked to original sources
PubMed1991

Proliferation in pituitary adenomas: measurement by MAb KI 67.

The monoclonal antibody MAb KI 67 reacts with a nuclear antigen throughout the entire cell cycle and allows easy evaluation of proliferating tumour cells on routinely prepared smear and frozen sections. 120 pituitary adenomas were investigated by use of the monoclonal antibody KI 67 in a two-step avidin-biotin-peroxidase complex (ABC) technique. The KI 67 labelling index (LI) ranged in all adenomas from 0.2 to 4.6%. In 90 cases of transphenoidally operated adenomas the dura of the sella floor was investigated histologically. Adenomas with histologically proven dural infiltration showed a statistically significant higher KI 67 LI (p less than 0.001) compared to non-invasive adenomas.

Adenoma↗
PubMed1991

Modifications of temporal approaches: anatomical aspects of a microneurosurgical approach.

All subtemporal approaches have in common the risk of temporal lobe damage. To reduce the retraction of the temporal lobe we combine two synergistic modifications of temporal approaches to reach the prepontine space. The first is the temporary resection of the zygomatic arch which allows to bring the temporalis muscle more caudally and subsequently allows an anterior subtemporal approach with only minimal temporal lobe retraction. The second modification is the resection of the apex of the petrous bone after incision of the tentorium. This provides an excellent view into the posterior fossa between the trigeminal nerve medially, the internal carotid artery caudally and the internal auditory canal laterally. The anatomical aspects of a microneurosurgical approach regarding these modifications are reported and discussed.

Brain Neoplasms↗
PubMed1991

Diagnostic potential of stereotactic biopsy of midline lesions.

The technique of CT-guided stereotactic biopsy is described and its reliability is discussed based on the experiences with a series of 1747 procedures. We could show that stereotactic biopsy has an overall diagnostic accuracy of 95% and therefore is a safe and reliable tool for planning the therapeutic strategy.

Biopsy↗
PubMed1988

Criteria for preservation of vestibulocochlear nerve function during microsurgical removal of acoustic neurinomas.

A careful examination of the shape, location and course of the 8th cranial nerve in medium-sized and large tumours exhibits three distinct variants. In all cases where cochlear function was preserved, the type III variant (12%) in the cranial nerve tumour relationship was observed. The author's experience clearly indicates that, if a tumour is resected in toto, anatomical nerve continuity cannot be preserved in the type I and II variants (48%, respect. 40%). However, in the type I and II variants the patients invariably had preoperative hearing loss. The important criteria which must be considered in order to preserve cochlear function when extirpating acoustic neurinomas are an anatomically intact nerve, the origin of the tumour and its direction of spread, further more the shape, location and course of the 8th nerve components, the quality of preoperative cochlear nerve function, the pattern of vascularization of the statoacoustic nerve and the inner ear, and lastly, but not least a possible infiltration of the vestibular and/or cochlear nerves by the tumour itself. Objective hearing function could be preserved in 62% of small neurinomas (grade II) and 10% of large tumours (grades III and IV).

Audiometry, Pure-Tone↗
PubMed1985

Statistics of intracranial midline tumors in children.

Of the 1,280 pediatric brain tumors seen at the Department of Neurosurgery, University of Vienna, until December 1984 57% involved the midline. Midline tumors were supratentorial in 40% of cases and infratentorial in 60%. The distribution of different tumor types in the various anatomical regions follows the known sites of predilection of brain tumors. Orienting diagrams show their rates in numerical terms, in various regions as well as their "clinical" malignancy.

Austria↗
PubMed1985

Problems of surgical technique for the treatment of supratentorial midline tumors in children.

In this presentation the authors describe briefly their thoughts on microsurgical management of certain typical brain tumors arising from within and adjacent to the third ventricle the surgical treatment of which has for many years been essentially conservative, not infrequently without histological verification of the type of the tumor or even of the presence of a real neoplasm.

Brain Neoplasms↗
PubMed1985

Nimodipine treatment of ischemic neurological deficits due to cerebral vasospasm after subarachnoid hemorrhage. Clinical results of a multicenter study.

Intravenous Nimodipine was administered to 109 patients (65 female and 44 male) with either pre- or post-operative progressive neurological deterioration from cerebral vasospasm following subarachnoid hemorrhage from a ruptured aneurysm. In 91 of the patients the efficacy of Nimodipine in relieving ischemic symptoms was assessed and in all of the 109 patients the tolerance was evaluated. The aneurysms were related to following arteries: anterior communicating artery (41%), middle cerebral artery (24%), internal carotid artery (10%), vertebro-basilar arteries (4%) and others (5.5%); 11% of the patients had multiple aneurysms. On 16 of the 91 patients no surgery was performed. On 16% of the remaining 75 patients surgery was performed within 72 hours after the hemorrhage, 57% were operated between day 4 and day 15 and 29% after day 16. The ischemic neurological deficits occurred preoperatively in 67% of the patients and post-operatively in 23%. At the beginning of treatment 84% of the patients were graded III-V according to the Hunt and Hess grading system. Most of the patients received doses of 24-48 mg Nimodipine daily as constant i.v. infusion for 7-10 days. The grade of neurological deficit at the end of the treatment was evaluated according to the Glasgow Outcome Scale. 59 (65%) of the patients showed complete recovery or marked improvement of the ischemic symptoms while 22% remained unchanged and 11% died due to severe vasospasm. Administration of Nimodipine seemed to be more efficient in cases where treatment was started within 24 hours. In the patient group which was treated pre-operatively, recurrent hemorrhage was recorded in 8% of the patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Hydrocephalus in infancy and childhood: diagnosis and indication for operation.

Improvement of the prognosis for children suffering from hydrocephalus requires prompt diagnosis and reliable indication of surgical treatment. Today, intrauterine hydrocephalus is detectable within the first three months of pregnancy; in infancy, before the cranial sutures have fused, pathological growth of the head is the principal sign confirming together with anatomical examinations (ultrasound, CT scan) the indication of operative treatment. In later childhood, surgical treatment is only definitely indicated by symptoms and morphological examination of clearly active hypertensive hydrocephalus. Intermittently normotensive hydrocephalus (not "normal-pressure-hydrocephalus"!) showing symptoms adapted to childhood, however, often requires exact examination of intracranial pressure dynamics, including quantitative volume provocation test. "Step-by-step-procedure" is advisable (Table III).

Cerebrospinal Fluid Shunts↗
PubMed1984

Reconstruction of the facial nerve in acoustic neurinoma surgery. Juxtapontine-intratemporal nerve graft.

Five cases of large acoustic neurinomas (diameter 2.5 cm) with involvement of the facial nerve in the tumour capsule are presented. The preoperative function of the facial nerve was normal. During surgery, in order to achieve a radical tumour removal, the facial nerve was severed juxtapontine. Reconstruction was performed at the same procedure using a 5-6 cm long sural nerve graft. Thus the central juxtapontine stump was joined to the peripheral stump in the facial nerve canal of the petrous bone. After six months, all five patients exhibited a well functioning mimic and a good eyelid function. At the one year control four patients had normal nerve function clinically and one patient still showed asymmetrical mimic.

Adult↗
PubMed1976

[Extra-intracranial anastomosis technic].

This is a report about the author's surgical experiences with extra-intracranial anastomosis. Special attention is drawn to various technical measures for avoiding postoperative complications. It seems very important to leave around the temporal superficial artery a mantle of connective tissue to preserve the vascular supply of the vessel wall and to facilitate safe manipulation of the artery. Further more the report deals with the bloodflow direction in the temporal superficial artery in relation to the middle cerebral artery- the flow should be directed to the trunk of the middle cerebral artery in order to effect an optimal perfusion of the supplying area of the middle cerebral artery. Approx. 8 to 10 mm should hold the incision in both arteries, end of temporal superficial and side of middle cerebral, to attain a wide opened junction between both arteries and to prevent obstruction. Attention is called to the risk of skin necrosis when using both, frontal and parietal branches of the temporal superficial artery. High value is set on covering the bone and dura deficiency with muscle lobe to prevent spreading and fistula of cerebral spinal fluid.

Arteriovenous Shunt, Surgical↗
PubMed1975

[The importance of the histological structure of the superficial temporal artery for the functioning of the arterial extra-intracranian anastomosis].

After extra-intracranial anastomosis one could find a considerable dilatation of the superficial temporal artery in a relatively short period of time. This vessel as well as other arteries of the circulatory system were examined histologically. On the basis of a large amount of autopsy material the atherosclerotic changes of the different vessels were correlated. Thus it turned out that the superficial temporal artery revealed another type of atherosclerotic changes. A type which exhibited hardly any calcification, but shows an increase of elastic fibers which make dilatation of the vessel possible despite of its thickened wall and primarily narrowed lumen.

Adult↗