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Biomedical subjects

A van der Zwan

Publications and source records attributed to A van der Zwan.

At least 19 recordsLinked to original sources
PubMed2001

Flow quantification of the non-occlusive excimer laser-assisted EC-IC bypass.

BACKGROUND: For six years, we used the Excimer laser-assisted nonocclusive anastomosis technique for high-flow revascularization of the brain in patients with either nonclippable and noncoilable giant aneurysms of the internal carotid or basilar artery or progressive stroke associated with occlusive disease of the internal carotid artery. The aim of this study is to assess the blood flow capacity of this type of Extra-Intracranial bypass and its haemodynamic behaviour over time. METHODS: Twenty-six patients with a giant aneurysms and 8 patients with occlusive disease of the internal carotid artery were treated with the nonocclusive Excimer laser assisted EC-IC bypass. intra-operatively, direct measurements of flow in the EC-IC bypass were performed in all patients (Transonic Systems, Inc., Ithaca. NY). Postoperatively, follow up measurements of flow were performed with MR angiography in 14 patients with a giant aneurysm after occluding the internal carotid artery, and 7 patients with occlusive carotid disease. RESULTS: The mean flow in the laser assisted bypasses in the group of patients with a giant aneurysm was 158 ml/min after ligation or balloon occlusion of the ICA. The mean flow of the laser assisted bypass in the group of patients with ICA occlusive disease was 130 ml/min. A comparison with data on flow capacity of conventional EC IC bypasses is made. A demonstrated increase of flow in the bypass during follow up is discussed from a haemodynamic point of view. CONCLUSIONS: The results of this study demonstrate that the flow capacity of the nonoccluding excimer laser assisted bypass is much higher than the capacity of the conventional, more peripherally located conventional EC IC bypass, and should therefore be denoted as High-Flow EC IC bypass. Consequently, this type of bypass can be a powerful and safe tool in new revascularization strategies.

Adolescent↗
PubMed2001

Third ventriculostomy.

Since its description by Dandy in 1922, several techniques have been used to perform third ventriculostomy under endoscopic control. Except for the blunt technique, in which the endoscope is used by itself to create the opening in the floor of the third ventricle, the other techniques require more than one instrument to perforate the floor of the ventricle and enlarge the ventriculostomy. The new device described is a sterilizable modified forceps that allows both the opening of the floor and the enlargement of the ventriculostomy in a simple and effective way. The new device has the following characteristics: 1) the tip of the forceps is thin enough to allow the easy perforation of the floor of the ventricle; 2) the inner surface of the jaws is smooth to avoid catching vessels of the basal cistern; and 3) the outer surface of the jaws has indentations that catch the edges of the opening to prevent them from slipping along the instrument's jaws. The ventricle floor is opened by gentle pressure of the forceps, which is slowly opened so that the edges of the aperture are caught by the distal outer indentation of the jaws, leading to an approximately 4-mm opening of the floor. This device has been used successfully in 10 consecutive patients. This new device allows surgeons to perform third ventriculostomy under endoscopic control in a very simple, quick, and effective way, avoiding the need for additional single-use instruments.

Endoscopy↗
PubMed2000

Repeated quantitative perfusion and contrast permeability measurement in the MRI examination of a CNS tumor.

This study reports on the results of quantitative MRI perfusion and contrast permeability measurement on two occasions in one patient. The measurements were separated 81 days in time. The tumor grew considerably in this period, but no change was found with respect to perfusion and contrast permeability. Non-involved white matter values were reproduced to demonstrate repeatability. The presented approach to dynamic susceptibility contrast MRI allows fast and repeatable quantitative assessment of perfusion and is easily integrated in a conventional brain tumor protocol.

Adult↗
PubMed2000

Scanning electron microscopic evaluation of nonocclusive excimer laser-assisted anastomosis in rabbits.

BACKGROUND: The nonocclusive Excimer laser-assisted bypass technique has been described in previous studies and proved to be a promising bypass operation in vascular brain surgery. Little is known about the morphological regeneration process of the laser-assisted anastomosis in time. By way of a scanning electron microscopic study we examined the way in which the anastomosis site created by the nonocclusive Excimer laser-assisted anastomosis technique becomes endothelialized. METHODS: In 14 rabbits the internal jugular vein was placed in a loop on the abdominal aorta. The distal anastomosis was made using the nonocclusive Excimer laser-assisted technique. The proximal anastomosis was made either laser-assisted or conventional end-to-side. After clipping of the aorta between the two anastomoses sites the vein served as a bypass. To evaluate the endothelialization at the laser-assisted anastomosis site in time, a scanning electron microscopic study was performed. RESULTS: In the first hours after the bypass operation a new intimal surface is formed by fibrin and activated platelets. Some leukocytes are seen during the first days. The endothelialization process of the laser-assisted anastomosis site begins one day after the operation. The gradual endothelialization process evolved along two lines. First, endothelial cells grow from the side of the aorta to the bypass. Second, after one day solitary (blood-borne) endothelial cells deposit on the laser edge and the sutures, covering the platelet aggregates. CONCLUSIONS: The endothelialization of the Excimer laser-assisted anastomosis is more or less completed 9 days after the operation. The edge created by the laser becomes smoother after a few days and is gone for the most part after 9 days.

Anastomosis, Surgical↗
PubMed1999

[High-flow transcranial bypass for prevention of brain ischemia].

In patients in whom the internal carotid artery has to be occluded because of the presence of an intracranial giant aneurysm or an infiltrating skull base tumour and in patients with brain ischaemia, whose internal carotid artery has been occluded spontaneously on the basis of atherosclerosis, a transcranial bypass can be created. Since the beginning of the seventies 'low-flow bypasses' are made in which a branch of the superficial temporal artery is connected with a cortical branch of the middle cerebral artery. Because of the small calibre of the blood vessels involved the desired effect on the brain circulation is limited. Thanks to the nonocclusive Excimer laser-assisted anastomosing technique, developed by Tulleken et al. in the last fifteen years, it is now possible to create a high-flow bypass in a safe way. A donor vessel, e.g. the V. saphena magna, is connected at one end to the external carotid artery and at the other to the intracranial part of the internal carotid artery beyond the pathological lesion. The mean flow through the bypass was 140 ml/min in about 90 patients. For example, in three patients, a woman aged 45 with rightsided progressive ophthalmoplegia due to a giant aneurysm, a woman aged 31 years with an aneurysm in the right middle ear and a man with a chemodectoma at the base of the skull, a transcranial high-flow bypass was created nonocclusively, after which the internal carotid artery was closed without any problems.

Adult↗
PubMed1998

High-flow bypass using nonocclusive excimer laser-assisted end-to-side anastomosis of the external carotid artery to the P1 segment of the posterior cerebral artery via the sylvian route. Technical note.

In a patient with a giant aneurysm of the basilar artery trunk, a vein graft was interposed between the external carotid artery in the neck and the P1 segment of the posterior cerebral artery. Balloon occlusion of both vertebral arteries was performed 3 days later. The sylvian route was used for the grafting procedure and the connection to the posterior cerebral artery was made by using the excimer laser-assisted nonocclusive anastomosis technique.

Adult↗
PubMed1995

[Postpartum complication: 'postpartum headache' (thrombosis of the superior sagittal sinus)].

A 34-year-old woman was admitted on the 10th day post partum complaining of loss of strength in the left arm and headache. The next day she started having seizures. Although the clinical picture suggested sinus thrombosis, initially a CT scan showed no abnormalities. The diagnosis of sinus sagittalis superior thrombosis was finally made by means of arteriography. The patient was treated successfully with anticoagulants and recovered without sequelae.

Acenocoumarol↗
PubMed1994

[Vigabatrin: results with a new antiepileptic agents in 57 patients in a general neurological practice].

OBJECTIVE: To obtain answers to the following questions: can vigabatrin replace other anti-epileptics? Is it feasible to use VGB as a monotherapy? DESIGN: Retrospective, descriptive. SETTING: Neurological outpatient clinic of the Sophia Hospital in Zwolle, the Netherlands. METHOD: In 57 of the 492 (28 men, 29 women) patients suffering from epilepsy who had been treated for more than 1 year, VGB (500-4000 mg/day) was added to the regimen because of persistent attacks (n = 21), adverse effects of other medication (n = 14) or both (n = 22). Mean age was 45 years (3-77). In the end, 17 patients were treated with VGB alone. The average frequencies of attacks and the adverse effects before and after start of VGB treatment were compared. RESULTS: Almost all patients who had suffered from partial attacks became attack-free, as well as the majority of patients with generalised tonic-clonic attacks or a combination of these with partial attacks. In 5 patients from this group a status epilepticus occurred. The patients with infantile spasms became attack-free. Drowsiness and headache were the most frequent side-effects. Psychosis occurred in one patient. Eventually 11 of the 17 patients on VGB monotherapy became attack-free. CONCLUSIONS: Adding VGB to the original AE, but also partial or full replacement of other AE by VGB in therapy-resistant epilepsy, can make a number of patients attack-free. This applies in particular to patients with partial epileptic attacks and infantile spasms.

4-Aminobutyrate Transaminase↗
PubMed1993

[Lyme psychosis].

A woman aged 64 was admitted to the psychiatric department because of a psychotic decompensation with visual hallucinations, disorientation in time and space and associative thinking. On psychotropic drugs the condition failed to improve; subsequently neurological symptoms developed. EEG abnormalities prompted a lumbar puncture. In the CSF a strong plasma cell reaction with atypical cells was observed. The enzyme immunoassay for Borrelia burgdorferi was positive and after treatment with penicillin the psychiatric and neurological signs and symptoms disappeared. From the history which could then be taken it appeared that the patient had been bitten by ticks. Her husband aged 66 years passed through a similar episode of disease.

Antibodies, Bacterial↗
PubMed1993

A quantitative investigation of the variability of the major cerebral arterial territories.

BACKGROUND AND PURPOSE: We have previously reported that the topographic variability of the territories of the anterior, middle, and posterior cerebral arteries is much larger than is generally considered in the literature. In the current study, we quantitatively investigated the variability of the territorial distribution of the major cerebral arteries and analyzed its relation to the variability of the circle of Willis. METHODS: In 23 human brains, the volumes of the major cerebral territories were calculated and the diameters of the contributing arteries were measured and standardized for size. RESULTS: The variability of the standardized territorial volumes proved to be considerably large and strongly correlated with the variability of the diameters of the arteries emanating from the circle of Willis. Furthermore, the relative vascular densities in the gray and white matter were determined. Taking these densities into account, an estimation of the relative peripheral resistance of the contributing arteries was made. CONCLUSIONS: We hypothesize that the morphological variability of the cerebral vascular system is related to the peripheral resistance of the major cerebral arteries and, consequently, to flow patterns, both of which are hemodynamic factors. We suggest that hemodynamic factors predominantly determine the form and size of the cerebral vascular system.

Brain↗
PubMed1992

[Ibuprofen meningitis].

A case of aseptic meningitis in an otherwise healthy women aged 47 yr after taking one tablet containing 400 mg ibuprofen is reported. The patient recovered in a few days.

Female↗
PubMed1992

Variability of the territories of the major cerebral arteries.

Recent morphological and functional studies on the circle of Willis suggest that the areas of supply of the six major cerebral arteries show a considerable variation in distribution, in contrast to the relatively consistent pattern generally accepted; therefore, the cortical and intracerebral distribution of the territories of these arteries was investigated in 25 unfixed human brains obtained at routine autopsy. The six major cerebral arteries were simultaneously injected under the same pressure with different-colored Araldite F mixtures under standardized conditions to obtain the most realistic territorial distribution. The cortical boundaries were examined and recorded in relation to the cerebral gyri and sulci, and the territories of the anterior, middle, and posterior cerebral arteries were analyzed and compared. The intracerebral distribution of these territories was investigated after the injected brains were cut in parallel slices. The variability of the territories of these arteries was much larger than generally described in the literature. Twenty-six variations in the territory of the anterior cerebral artery, 17 variations in the area of the middle cerebral artery, and 22 variations in the area of the posterior cerebral artery were found in the cortex of 50 hemispheres. Intracerebrally, the anterior, middle, and posterior cerebral arteries contributed in varying degrees to the blood supply of the lobar white matter, the internal capsule, the caudate nucleus, and the lentiform nucleus. The large variation in the area in which the cortical and intracerebral boundaries between these territories was located was demonstrated by illustrating the minimum and maximum extent of each. The results are compared with prior findings, and their implications for both experimental model studies and clinical practice are discussed.

Adolescent↗
PubMed1991

Review of the variability of the territories of the major cerebral arteries.

The results of recent model studies indicate that the variability in territorial distribution of the major cerebral arteries may be much greater than has been previously recognized. We review the literature on the cortical and intracerebral territories of the anterior, middle, and posterior cerebral arteries. Although most authors claim that these territories are relatively consistent, the results of their studies show many and considerable discrepancies. The variability described by Beevor has been neither excluded nor completely confirmed, yet somehow the concept of a relatively unchanging pattern of the peripheral cerebral vascularization has gradually settled into the literature. We discuss the considerable variability of the cerebral territories, as well as the discrepancies in investigation techniques, injection materials, and specimen conditions that could be factors producing these dissimilar results. Our study shows that there are no arguments in the literature to negate the variability of the cerebral territories.

Caudate Nucleus↗
PubMed1989

[Transient Parkinson syndrome and tremor caused by the use of sodium valproate].

From 1986 till 1988, 88 patients received sodium valproate for the first time as a therapy for epilepsy. One of them developed a fine tremor, three a coarse tremor with a cogwheel phenomenon, two developed a full parkinsonian syndrome. All these symptoms in these six patients disappeared completely or nearly completely after changing to another anti-epileptic drug or reducing the dose.

Aged↗