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Biomedical subjects

A J van der Werf

Publications and source records attributed to A J van der Werf.

At least 19 recordsLinked to original sources
PubMed1989

[Direct arteriovenous fistula in the neck: one of the causes of tinnitus].

The most frequent symptom of an arteriovenous fistula is a bruit, often audible to the patient himself. The indication for treatment of such fistulae depends on the severity of the symptoms and on the risks of excessive strain on the heart, circulatory insufficiency and haemorrhages. The treatment of choice of direct communications between arteries and veins is detachable balloon occlusion by a transvascular technique rather than surgery. The method is described and three personal cases are reported. There were no complications, and the hospital stay was limited to 2-3 days.

Adolescent↗
PubMed1988

Oligodendroglioma. A comparison of two grading systems.

In order to compare the grading system for oligodendrogliomas described by M.T. Smith (1983) with the conventional grading system according to Kernohan (1938), specimens from 72 patients were graded according to both systems, and survival times of the patients were compared. Survival rates decline in older patients. No interaction between the age of the patient and the degree of the tumor was found. No influence of localization of the tumor on survival was found. Similar to the system of Kernohan, the grading system of Smith distinguishes between only three groups of patients with significantly different survival times. In Smith's Grade A and Kernohan's Grade 1 the longest survivals are found; while in Smith's Grade D and Kernohan's Grade 4 the shortest survivals are found. Smith's Grades B and C as well as Kernohan's Grades 2 and 3 were intermediate with respect to the survival times of the patients and did not significantly differ from each other. With the independently significant features (cell density, pleomorphism, and necrosis) evaluated according to simple on-off scoring, and with the reduction from four grades to three, the grading system according to Smith would provide a simple and good, concise grading system for oligodendrogliomas of the brain.

Age Factors↗
PubMed1986

Maturation of a primitive neuroectodermal brain tumor? A case study with some remarks on the classification and nomenclature of 'primitive' CNS tumors.

A brain tumor in a 4-year-old child is described. The neoplasm was partly cystic and showed an a-typical multi-differentiated aspect. Microscopically the neoplasm had a clear-cut 'malignant' morphology. This tumor represents possibly a partly maturated primitive neuroectodermal brain tumor. The term PNET is briefly discussed in relation to the clinical implications.

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

Facial nerve function after suboccipital removal of acoustic neurinoma.

The recovery of facial nerve function after suboccipital removal of 91 acoustic neurinomas is presented. The results after anatomical preservation of the nerve (60 cases), direct anastomosis of the nerve (7 cases), nerve grafting (16 cases), and facial hypoglossal anastomosis (8 cases) are presented after a follow-up period of 31.2 months. A simplified classification was used to describe motor function. The results are compared to those in the literature.

Adolescent↗
PubMed1980

Detachable balloon technique in the treatment of direct carotid-cavernous fistulas.

This paper describes the results obtained in the treatment of posttraumatic carotid-cavernous fistulas in 7 patients. The method used consisted of closure of the fistula with the aid of a detachable balloon. The advantage of this method over most others is that it closes the fistula but leaves carotid patency intact. In addition to the results, some technical aspects of this method are discussed.

Adolescent↗
PubMed1979

Detection of B-cell-specific alloantibodies in pregnancy sera in the lymphocytotoxicity and the indirect immunofluorescence techniques.

Two hundred and eight pregnancy sera were tested for the presence of antibodies specific for lymphocyte sub-populations by using the isolated B and T lymphocytes from the women's mating partners. This was done by the microlymphocytotoxicity and the indirect immunofluorescence techniques. Five sera (2.5%) reacted exclusively with B lymphocytes and sixty-three sera (30.2%) reacted with both B and T lymphocytes; none of the sera was specific for T cells. Several sera, reacting with both B and T lymphocytes, were absorbed with platelets and this procedure revealed nine additional antiseraa specific for B lymphocyte antigens. Specificity studies on a panel of forty-eight HLA-ABCD typed individuals indicated that most antisera possibly defined new B-cell antigens. Family studies established that the antigens defined by these antiser were coded for by genes in the Major Histocompatibility Complex.

Antibody Specificity↗
PubMed1977

Craniosynostosis: a new operative technique.

In the treatment of craniosynostosis several methods have been proposed to prevent craniectomies from early reclosure. New bone is formed at the edge of the craniectomy, but particularly at the outer surface of the dura. The author has developed a method to separate the edges from each other and to stop osteogenesis inside the craniectomy. The outer layer of the dura is dissected free from the inner layer folded over the edge of the groove and sutured to the outer periosteum. The operative technique and the results in 40 patients with a follow up of 17 years are described.

Child↗
PubMed1977

[Craniosynostoses (17 years of experience with a new surgical technic)].

In the treatment of craniosynostosis methods have been proposed to prevent craniectomies from early reclosure. New bone is formed at the edge of the craniectomy but particularly at the outer surface of the dura. The author has developed a method to separate the edges from each other and to stop osteogenesis inside the craniectomy. The outer layer of the dura is dissected free from the inner layer, folded over the edge of the groove and sutured to the outer periosteum. The operative technique and the results in 40 patients with a follow up of up to 17 years are described.

Child↗
PubMed1975

Surgical management of acute subdural hematomas.

Acute subdural hematoma, local cerebral laceration and severe brain edema must be diagnosed at the earliest possible stage preferably by angiography and must be treated promptly by craniectomy of an adequate size in order to cope with all the blood clot, the lacerated brain tissue and the swollen brain.

Acute Disease↗