Venous drainage in hemorrhage from AVM's.
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Arteriovenous Malformations↗
Biomedical subjects
H A van Alphen
Publications and source records attributed to H A van Alphen.
Primary spinal epidural extraosseous Ewing's sarcoma.
The case of a 7-year-old boy with a spinal epidural extraosseous Ewing's sarcoma (EES) is presented. He is in complete remission without neurologic deficit 40 months after diagnosis. Another 15 cases were found in the literature and are discussed together with this patient. Twelve of them were male patients. The mean age of the patients was 17.5 years (range, 4 to 47). Symptoms included back pain and/or radicular pain (100%), paresis of one or both legs (83%), sensory disturbances, and bladder and bowel dysfunction. The mean diagnostic delay was 5.8 months. Each patient underwent laminectomy; complete resection of the tumor was impossible in more than 50% of the cases. Most patients received radiation therapy and/or chemotherapy. Four patients suffered from local recurrence, eight from metastases. Ten (63%) patients died, 1 to 48 months (mean, 16) after diagnosis. The differential diagnosis is discussed, including disk herniation and several benign and malignant tumors.
Antineoplastic Combined Chemotherapy Protocols↗
Multiple cerebral de novo aneurysms.
The new development of two remarkable cerebral mirror aneurysms is described in two female patients, who had been surgically treated for a mid-line aneurysm several years previously. The phenomenon of mirror aneurysms makes it likely that an inborn weakness of the vessel wall is one of the underlying causes of cerebral aneurysms. Acquired alterations of the vessel wall and hemodynamic forces, on the other hand, also play an important role in the genesis of aneurysms.
Adult↗
Pathological changes in experimental saccular aneurysms in the carotid artery of the rat.
Although the reason for development of saccular aneurysms in humans has still not been elucidated, the process might be observed and explained using a reproducible aneurysm model in vivo. In this paper, a sequential pathological study of the experimental saccular aneurysms was made. No additional influential factors were applied. At all stages of the development between the induction and 6 months, the histology of the aneurysm wall was similar to that of human aneurysms. The imbalance of the degeneration and regeneration processes during the development of these experimental aneurysms is discussed according to the pathological findings in different periods. Haemodynamic stress and different regenerative speeds in different arterial tissues must be responsible for the saccular aneurysm formation and growth.
Aneurysm↗
Effect of contralateral carotid ligation on experimental carotid artery aneurysm in the rat.
Haemodynamic factors in the formation and development of saccular aneurysms have been widely studied. Saccular aneurysms could appear and grow at the side of the increased blood flow. The effects of contralateral carotid ligation on the formation and growth of our experimental saccular aneurysms were studied. Measurement and pathological examination showed that the haemodynamic changes could facilitate the development of saccular aneurysms, but by itself could not bring about their formation.
Aneurysm↗
A method for temporary and repeated increase of blood pressure in the rat, using intraperitoneal adrenaline injections.
In experimental studies, permanent hypertension has been considered to be an important factor in aneurysm formation and growth. However, in clinical studies it has been found that saccular aneurysms often develop and rupture in some patients without persistent hypertension. Environmental events that temporarily and repeatedly increase blood pressure do not take an equivalent length of time in vivo but have been noted as factors in the growth or rupture of saccular aneurysms. In order to test the effect of intermittent blood pressure elevations on saccular aneurysm formation and growth, a reliable method for temporarily and repeatedly increasing blood pressure should be developed first and in this paper, such a model is described. It is based on the intraperitoneal injections of adrenaline in rats, a route which does not seem to have been used so far.
Aneurysm↗
Effect of intermittent blood pressure elevation on the growth of experimental saccular aneurysms in the rat.
In this study we applied the technique described in the previous paper (see pp. 103-106 of previous issue (1991); 13(2)) to rats with experimental saccular aneurysms. We found that the mean sizes and some growth ratios of experimental aneurysms were significantly larger in the intermittent blood pressure elevation groups than in the control groups. The increase of growth ratios was proportional to the number of transient blood pressure elevations. The morphological structure of these saccular aneurysms showed that the regenerative processes in the aneurysm wall had obviously been interfered with in animals with intermittent blood pressure elevation. The effective mechanism of this influential factor is discussed.
Aneurysm↗
[Revised guidelines for the treatment of patients with severe traumatic brain injury].
The early assessment and acute treatment of patients with severe traumatic brain injury require a well structured and organized policy. This policy should include rapid transport to, and effective first aid in trauma centres especially equipped for this purpose, adequate communication of information between the (para-)medical workers successively involved and a multidisciplinary handling of diagnostics and treatment of the various traumatic and posttraumatic conditions. This requires the imposition of unequivocal priorities known to all concerned. In this paper, which was written in cooperation with the different medical disciplines concerned, the main features of the acute treatment of severe head injury, about which a wide agreement was reached, are worked out in 18 theses. The guidelines regard the admission and first aid, the diagnostic procedures and the conservative and surgical treatment of patients with severe head injury. These guidelines can be developed in the different hospitals into detailed blueprints for the treatment, in accordance with the local situation.
Brain Injuries↗
Pathogenesis and histopathology of saccular aneurysms: review of the literature.
In this paper, the major theories on the formation and growth of saccular aneurysms are reviewed on the basis of previous clinical, pathological and experimental studies. Which is the critical layer is still the focus of debate. Current ideas can be summarized as follows: most researchers think that disruption of the internal elastic lamina is an essential requirement for the creation of saccular aneurysms because it is this layer that provides most of the strength to the arterial wall, especially in cerebral arteries. Degeneration of this layer is a constant feature of all saccular aneurysms. A coexisting medial defect and haemodynamic stress at an apex may aggravate degeneration at that point. Hypertension does not seem to be the major factor in some aneurysm patients, but it may facilitate the formation and growth of saccular aneurysms. An atheroma is often associated with saccular aneurysms, but its effect on this pathological process is still unknown. Other factors are discussed concisely. Previous experimental methods and their results pertaining to the formation and growth of this type of aneurysm are also reviewed. A reproducible animal model is still required to allow various theories to be tested.
Adult↗
An acute experimental model of saccular aneurysms in the rat.
A new and reproducible saccular aneurysm model has been developed at the bifurcation of the common carotid artery in rats. The details of the experimental methods and results are described. It is strongly suggested that the internal elastic lamina is a critical layer in saccular aneurysm formation, because an experimental saccular aneurysm can be produced immediately by transluminally damaging the inside of the arterial wall at the bifurcation of the common carotid artery. This saccular aneurysm model has several advantages: (i) it can be induced quickly and the success rate approaches 100% in rats; (ii) this technique can produce satisfactory experimental saccular aneurysms for other aneurysm studies, and in the future it will also be possible to use this technique to produce experimental saccular aneurysms in cerebral arteries of large animals.
Animals↗
Observations on experimental saccular aneurysms in the rat after 2 and 3 months.
After 2 and 3 months we re-exposed 20 experimental saccular aneurysms. Under the operating microscope, we measured their sizes and compared them with the sizes immediately after induction. All aneurysms had grown significantly and none was thrombosed. Pathological examinations showed that the sac of the aneurysm was similar to that of the human saccular aneurysms. Based on the operating microscopy and pathological findings we postulate that abnormal histological structure and haemodynamic stress are the major causes of aneurysm enlargement. We also noted that there were some regenerative processes in these experimental aneurysm walls. The results prove that this model is reliable, because these aneurysms have the main characteristics of human saccular aneurysms, not only grossly but also microscopically.
Animals↗
Regulations on brain death in the Netherlands.
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Brain Death↗
Chemonucleolysis versus discectomy: a randomized multicenter trial.
A randomized clinical trial was carried out to compare the results of open discectomy with those of chemonucleolysis in 151 patients suffering from a disc herniation at L4-5 or L5-S1. All patients fulfilled strict entry criteria; 78 patients underwent open discectomy and 73 were subjected to chemonucleolysis. An increase in radicular pain immediately after treatment was encountered in 16 patients (22%) in the chemonucleolysis group, as compared to none in the discectomy group. The efficacy of discectomy appeared to be definitely superior to that of chemonucleolysis. Within a follow-up period of 1 year, 18 patients (25%) required open discectomy following failed chemonucleolysis; two patients (3%) in the discectomy group needed a second operation. Open discectomy following previous chemonucleolysis was successful in only 44% of cases. Comparison of the final results of the two modes of treatment 12 months after the last intervention (including second treatment) did not reveal any significant differences. The duration of the preoperative symptoms, the level of disc herniation, and the leakage of contrast medium out of the disc appeared to be of no relevance to the final outcome. The complication rates in both treatment groups were low.
Adolescent↗
[Chemonucleolysis or surgery in lumbar nucleus pulposus hernia?].
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Evaluation Studies as Topic↗
[Chemonucleolysis or herniotomy; results from a comparative study in patients with lumbar nucleus pulposus hernia].
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Adolescent↗
Chemonucleolysis or discectomy? Results of a randomized multicentre trial in patients with a herniated lumbar intervertebral disc (a preliminary report).
A randomized trial was carried out to compare the results of discectomy and chemonucleolysis in 151 patients, suffering from lumbar disc herniation L4-L5 or L5-S1. All patients fulfilled strict entry criteria. Seventy eight patients underwent surgical discectomy, 73 were treated with chemonucleolysis. Within one year of follow-up 18 patients (25%) required surgery after chemonucleolysis, whereas 2 patients (3%) in the surgery group underwent re-operation. Increase of radicular pain within 30 days after treatment was encountered in 16 patients (22%) in the chemonucleolysis group, as compared to none in the surgery group. The results of open surgery after preceding chemonucleolysis was successful in 44% and unsuccessful in 56%. The final result of chemonucleolysis, including second treatment, was still slightly less favourable (73%) the result of primary surgery (79%).
Adolescent↗
The value of continuous intra-operative EEG monitoring during carotid endarterectomy.
In a retrospective study, an evaluation was made of the intra-operative EEG findings and clinical results of 100 consecutive carotid endarterectomies carried out in 90 patients over the period 1977 to 1983. There was no operation-associated mortality; the peri-operative morbidity was 5%. All operations were performed maintaining the systemic blood pressure some 20% above the patients normal value. No interval shunt was used. The surgical policy was not influenced by EEG findings in any of the procedures. There was no relationship between carotid-clamping time and intra-operative EEG changes, nor was there a relationship between EEG changes and clinical outcome. It is most likely that neurological deficit following carotid endarterectomy, if operation is performed during elevated systemic blood pressure, is not due to haemodynamic disturbances, as a consequence of critical reduction of cerebral blood flow during internal carotid artery clamping, but to micro-embolism. From this assumption, it can be concluded that peri-operative complications of carotid endarterectomy cannot be reduced by intra-operative EEG monitoring.
Adult↗
Pregnancy-related primary brain and spinal tumors.
We reviewed the literature concerning primary brain and spinal tumors with first manifestation or acceleration of symptoms during pregnancy or within the first postpartum week and encountered four new cases in our center. The incidence of brain tumors that become symptomatic during pregnancy appears to be decreased compared with that in age-matched women. The relative frequency of the different primary brain tumor types is not changed by pregnancy. The number of meningiomas gradually tends to increase during pregnancy, with gliomas and spinal vascular tumors accumulating in the first and third trimesters, respectively. Postpartum amelioration of symptoms has especially been described for meningiomas and spinal vascular tumors. We conclude that different types of tumors are influenced at different stages of pregnancy. Although progesterone receptors predominate compared with estrogen receptors, no definite causal relationship with progesterone has been established.
Adult↗