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The Nuffield Department of Surgical Sciences is the academic department of surgery at the University of Oxford, and hosts a multidisciplinary team of senior clinical academic surgeons, senior scientists, junior clinicians and scientists in training.
Stent jail of the renal arteries in stent graft exclusion of AAA. An in vitro study of 3 different stent types.
BACKGROUND: The success of endoluminal stent grafts (ELG) is critically dependent on secure proximal fixation of the graft. Different types of stent grafts with uncovered proximal portions for transrenal fixation are obtainable. The present in vitro study was designed to elucidate how the flow parameters were altered by stent jail of the renal arteries with respect to different stent design. METHODS: The experiments were performed in an in vitro pulsatile circulation model. An aortic segment with bilateral side branches (like renal arteries) constructed of an ePTFE graft was perfused in the circulation model. The flow measurements were based on the ultrasound transit-time method. By varying the frequency from 30 to 100 bpm the flow parameters were altered and recorded continuously. Renal stent jailing was carried out using different stent types: Gianturco-Z-Stent, Palmaz-Stent, Powerlink Endologix. RESULTS: The flow in the aortic model increased from 1100 ml per minute to 3330 ml per minute depending on the pump frequency. In the control group without stent jail the renal flow was measured between 240 ml per minute up to 810 ml per minute. The ratio of renal flow was between 0.22 and 0.24 of the aortic flow. In the Palmaz group the ratio was between 0.21 and 0.24, in the Gianturco group between 0.23 and 0.25, and in the Powerlink group between 0.24 and 0.25 (unpaired-"t"-test: n.s.). CONCLUSIONS: The covering of the renal arteries and/ or superior mesenteric artery in case of long bared proximal stent raises the question whether the stent jail may result in flow reduction in the arteries covered or not. The present in vitro study demonstrated that the flow in the renal arteries is not decreased by these stent jails.
Prescribing practice with cognition enhancers in outpatient care: are there differences regarding type of dementia?--Results of a representative survey in lower Saxony, Germany.
Previous studies of cognition enhancers have mainly focused on insufficiently defined groups of cognition disorders, e.g., "cerebral insufficiency". With regard to the various biological changes in senile dementia of Alzheimer's type (SDAT) and in vascular dementia (VD), which together make up the great majority of senile dementias, many authors have encouraged different studies of these types of dementias, especially since both can be diagnosed clinically with satisfying certainty. Since primary care physicians treat the majority of elderly and demented patients, they have their own experience with cognition enhancers. We were therefore interested to know, how far these physicians differ in their treatment of SDAT and VD. We performed a representative survey (response rate 83.2%; 145 family physicians and 14 neuropsychiatrists) in the Goettingen area. A written case vignette described a 70-year-old widow with moderate dementia and vascular risk factors which are easily treated with drugs. Two versions were randomly assigned, in which (version A) either a "typical" VD history or a typical SDAT history (version B) were described. After perusal, the physician was asked whether and which drugs he would choose to treat the cognitive disorders in this patient. Most frequently, piracetam (A/B: 25.6%/30.9%), ginkgo biloba (24.4%/28.4%), and nimodipine (14.1%/25.9%) were considered. Aspirin was cited by 29.5%(A) and 17.3%(B) of the physicians respectively. As far as the type of dementia was concerned, significant differences were found only for co-dergocrine, which was preferred in SDAT. The following inter-group trends were observed: family physicians considered ginkgo biloba more often than nimodipine or co-dergocrine. The results show the apparent importance of cost-and safety aspects, while the type of dementia has hardly any impact. The latter impression corresponds to the results of drug trials demonstrating no different efficacy. In our opinion, aspirin was not sufficiently taken into consideration.
Sleep disturbances in the demented elderly: treatment in ambulatory care.
We report the results of a representative survey in Lower Saxony, Germany, that focused on the treatment of sleep disturbances in the moderately demented elderly. Two written sample case histories (vignettes) described either a vascular demented patient suffering from nocturnal wandering or an Alzheimer's-type demented patient without apparent psychotic or behavioral (sleep) disorder. These were randomly assigned and presented to 145 family physicians and 14 neuropsychiatrists working in private practice by a trained investigator, who then conducted a standardized interview with the physicians. The study was representative of physicians (response rate: 83.2%). In response to the question concerning how they would treat the patient's sleep disturbances, about 20% of the physicians (with respect to both versions) answered that they would not choose drugs. More than 40% considered neuroleptics to be the drugs of choice. Benzodiazepines, antidepressants and other substances were seldom considered. No significant difference was noted in the response to the two different case histories. The results allow for the conclusion that non-drug treatments, which (at least initially) should be the treatment of choice, are mainly disregarded by the majority of the ambulatory care physicians. The reason for this seems to be a lack of education in sleep medicine and also in geriatric medicine.
[Factors influencing the prescribing of nootropic drugs. Results of a representative inquiry in Lower Saxony].
AIM OF INVESTIGATION: To discover (1) to what extent patients' wishes and the extent of any abnormality of brain performance influence the frequency with which "nootropic" drugs (those thought to affect brain activity, e.g. piracetam, pyritinol, or improve cerebral circulation, e.g. xanthine derivatives, Ginkgo biloba, secale alkaloids, calcium antagonists) are prescribed; (2) the medical practitioner's expectations of the effectiveness of such medications. METHOD: In a personal interview, 145 family doctors and 14 neurologists in private practice in the Göttingen area of Germany (participation rate: 83.2% of those asked to participate) were questioned about fictitious cases (case 1: mild memory problem with or without expressed wish for medication; case 2: moderate dementia, of Alzheimer or multi-infarct type). The previously arranged interviews, which took place in the doctors' practice rooms, consisted of standardized open questions to the written case reports. RESULTS: Regardless of the wish of the patient and the extent and type of the abnormal brain function about 70% of all participating doctors would prescribe those drugs, even though about 56% had doubts about their effectiveness. About 28% expected a positive effect on brain performance. A nearly equal proportion of doctors would continue an existing drug regimen as would prescribe one. CONCLUSION: The prescription of the named group of drugs is influenced less by medical criteria than by factors which concern doctor-patient relationship.
Reasons for prescribing cognition enhancers in primary care. Results of a representative survey in Lower Saxony, Germany.
With regard either to the controversial debate about the efficacy of cognition enhancers (CEs) or to the high costs which the frequent prescription of these drugs causes the German health system's economy, we wanted to know what physicians expect from a therapy with these drugs. We performed a representative survey (response rate 83.2%) in Lower Saxony, Germany from February to July 1993. We designed two written case vignettes which described either a patient with slight memory problems or a moderately demented patient who also suffers from common systemic disorders. In a face-to-face interview 145 general practitioners and primary care internists (family physicians) and 14 community neuropsychiatrists answered the question, whether they would prescribe CEs to each of the patients described and what they would expect from this therapy. 70.4% of all physicians would prescribe a cognition enhancer to the slightly impaired patient and 63.5% to the multimorbid moderately demented patient, respectively. More than 50% of the family physicians would not expect any positive therapeutic effect in both patients, while the neuropsychiatrists did so in 57.1% in the patient with slight memory disturbances and in 35.7% in the moderately demented patient. A positive effect on cognition was expected by 28.2% of all physicians in the slight and by 18.3% in the moderately impaired patient, respectively. Other reasons mentioned were amelioration of cerebral perfusion and drive, as well as effects on disease progression. In conclusion, the results of this study clearly demonstrate that cognition enhancers are prescribed in spite of major doubts in their efficacy.
Diagnosis of dementia in primary care: results of a representative survey in lower Saxony, Germany.
To investigate whether an early diagnosis of dementia is established, whether a differentiation is made between vascular and primary degenerative etiology, and whether treatable causes of dementia are considered in primary care, we performed a survey using three written sample case histories describing slight memory impairment (case 1) or moderate dementia (case 2a: vascular dementia; case 2: degenerative dementia of Alzheimer type). The combinations 1 and 2a or 1 and 2b were randomly assigned and presented to ambulatory-care physicians (145 general practitioners and primary care internists and 14 neuropsychiatrists in private practice) in Göttingen and rural surroundings by a trained investigator who then performed a standardized interview. The study was representative (response rate 83.2%). For the sample case with slight memory complaints 13.8% of all physicians arrived at a primary diagnosis of depression and 44.0% considered depression for differential diagnosis. Senile dementia of Alzheimer type was considered less often. In the sample cases with moderate dementia according to established scientific criteria, there was a striking under-diagnosis of dementia, and in both cases an over-diagnosis of underlying vascular etiology. Treatable causes of dementia, such as possible drug interactions and substance abuse, were considered only by a minority of physicians. In conclusion, memory deficits seem to be regarded mainly as consequences of disturbed cerebral perfusion, and dementia as well as depression and drug adverse effects seem to be under-diagnosed in primary care.
[Ambulatory treatment of sleep disorders in the aged].
An enquiry into the handling by medical practitioners of sleeping problems among elderly patients was conducted in southern Lower Saxony by personal interview, combined with a standard questionnaire. A typical case report had been drafted concerning a 70-year-old, previously healthy widow: her complaints were "nonspecific" and could be classified as an example of either depression, of the onset of senile dementia or as within normal limits for age. This case report was presented by two interviewers to 145 general practitioners (GPs) and 14 neurologists in private practice (response rate of 83.2%) who were asked how they would have treated the patient's sleeping disorder. 30.3% of the GPs and 14.3% of the neurologists would initially not have prescribed medication. Only GPs (19.5%) mentioned possible herbal medication. Sedative neuroleptics were preferred by 57.1% of neurologists and 26.2% of GPs, while benzodiazepines would have been given by 14% of both groups. Antidepressive drugs and chloral hydrate were chosen less often (5.7% and 2.5%, respectively). These data support the finding of a high frequency of neuroleptic prescriptions given to the elderly. They also make clear that the possibility of treatment without drugs is usually not sufficiently explored.
Prevalence of disabilities in a national sample of 3-year-old Israeli children.
The prevalence of chronic conditions and illnesses causing disability in Israeli Jewish children aged 2 to 3 years, born in 1980, was studied on the basis of a national sample (n = 9,854). Seventy-six principle medical conditions causing disability were defined. The study showed a total disability rate of 8.9%. Very low birth weight and family problems were considered risk factors for developmental delay or for disability. The prevalence of the children at risk was 2.4%. The disability rate among this group was 6 to 7.5 times greater than in the total population. Data were analyzed by selected demographic characteristics. Speech and language disorders and undefined developmental delay were more prevalent among children of mothers with a low educational level. Speech and language disorders were also more prevalent among children born to mothers of Asian origin. Speech and language disorders, asthma and spastic bronchitis, hearing impairment and undefined developmental delay were more prevalent among male children. This is the first comprehensive nation-wide prevalence study of children with disabilities in Israel.