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51.
52.
The primary objective of revascularization procedures in the posterior circulation is the prevention of vertebrobasilar ischemic stroke. Specific anatomical and neurophysiologic characteristics such as posterior communicating artery size affect the susceptibility to ischemia. Current indications for revascularization include symptomatic vertebrobasilar ischemia refractory to medical therapy and ischemia caused by parent vessel occlusion as treatment for complex aneurysms. Treatment options include endovascular angioplasty and stenting, surgical endarterectomy, arterial reimplantation, extracranial-to-intracranial anastomosis, and indirect bypasses. Pretreatment studies including cerebral blood flow measurements with assessment of hemodynamic reserve can affect treatment decisions. Careful blood pressure regulation, neurophysiologic monitoring, and neuroprotective measures such as mild brain hypothermia can help minimize the risks of intervention. Microscope, microinstruments and intraoperative Doppler are routinely used. The superficial temporal artery, occipital artery, and external carotid artery can be used to augment blood flow to the superior cerebellar artery, posterior cerebral artery, posterior inferior cerebellar artery, or anterior inferior cerebellar artery. Interposition venous or arterial grafts can be used to increase length. Several published series report improvement or relief of symptoms in 60 to 100% of patients with a reduction of risk of future stroke and low complication rates. 相似文献
53.
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J S Marks J P Koplan C J Hogue M E Dalmat 《American journal of preventive medicine》1990,6(5):282-289
Research has shown that pregnant women who smoke cigarettes increase their risk of having low birthweight (LBW) infants. Recent randomized trials indicate that women who quit smoking early in pregnancy reduce their risk of delivering a LBW infant. Using various sources, we estimated the cost-effectiveness of a smoking cessation program for preventing LBW and perinatal mortality. Assuming the program would cost $30 a participant and that 15% of the participants would quit smoking, we determined that a program offered to all pregnant smokers would shift 5,876 LBW infants to normal birthweight and would cost about $4,000 for each LBW infant prevented. Since infants born to smokers are at 20% greater risk for a perinatal death, a smoking cessation program could prevent 338 deaths at a cost of $69,542 for each perinatal death averted. Compared with the costs of caring for these LBW infants in a neonatal intensive care unit (NICU), smoking cessation programs would save $77,807,054, or $3.31 per $1 spent. The ratio of savings to costs increases to more than six to one when we include reducing long-term care for infants with disabilities secondary to LBW in the benefits from smoking cessation programs. These findings argue for routinely including smoking cessation programs in prenatal care for smokers. 相似文献
55.
56.
Oscillatory motion of the normal cervical spinal cord 总被引:2,自引:0,他引:2
57.
Periosteal Ewing sarcoma 总被引:3,自引:0,他引:3
58.
Adjuvant therapy for pituitary adenomas: the possible role of photodynamic therapy. 总被引:1,自引:0,他引:1
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P. V. Marks 《Annals of the Royal College of Surgeons of England》1995,77(4):308-312
Although benign, pituitary adenomas may not always be curable by surgery alone. This is usually owing to dural infiltration and the technical problems of removal of involved dura in the sellar region. In such circumstances, some form of adjuvant therapy may be needed to address residual tumour and forestall recurrence. Radiotherapy and drugs, such as bromocriptine or octreotide, although effective are far from ideal adjuvant therapies and this has led to the study of the effects of photodynamic therapy on pituitary adenomas. It has been shown that photodynamic therapy using the photosensitising drugs haematoporphyrin derivative and aluminium phthalocyanine is active experimentally against these tumours. This could provide another useful weapon to use against these challenging lesions. 相似文献
59.
60.
In a prospective, randomized study of insemination with donor semen,
intracervical insemination by straw was compared with insemination using a
cervical cap with an intracervical reservoir. A total of 91 patients
completed 486 treatment cycles. There were no significant differences in
age, parity, indication for insemination by donor, or method of cycle
monitoring between women who became pregnant and those who did not conceive
with either insemination method. In 236 standard intracervical insemination
cycles, 14 patients became pregnant (5.9% per cycle), whereas 38 patients
conceived in 250 cervical cap cycles (15.2% per cycle). Both the crude
pregnancy rates and the cumulative pregnancy rates calculated by the
Kaplan-Meier life-table method were significantly different (chi(2)-test, P
< 0.001, and log-rank test, P < 0.005 respectively). Pregnancy rates
in artificial insemination with cryopreserved donor semen may be improved
by the use of a cervical cap when compared to cervical insemination by
straw. The use of the cervical cap may prolong the exposure of the
spermatozoa to the cervical mucus and prevent the backflow of semen into
the vagina.
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