Endovascular Treatments for Brain Aack Introduction - Microsurgery: Advances, Simulations, and Applications - page 61

In European and US populations, cerebral artery dissection
occurs frequently in the extracranial section of the internal carotid
arteries; in Japan it occurs in the extracranial section of the vertebral
artery. For extracranial cerebral artery dissection, in almost all cases
brain attack is produced by cerebral ischemia. For intracranial
cerebral artery dissection, brain attack is caused by ischemia or
subarachnoid hemorrhage. In recent years, with the popular use of
CT and MRI, it has been frequently diagnosed from headaches and
asymptomatic condition.

2.3.5 Treatments

2.3.5.1 rt-PA (Tissue plasminogen activator: alteplase)

intravenous therapy

Principally, until now the basic treatments for stroke have been
the reduction of cerebral edema at ischemic regions, preventing
the growth of ischemic regions by improving the microscopic
circulation and at chronic stage rehabilitation for function recovery
and reoccurrence prevention. Actually there is no change in the basic
treatments. The National Institute of Neurological Disorders and
Stroke (NINDS) rt-PA Stroke study proved in 1995 the effectiveness of
rt-PA intravenous treatments for ischemic cerebrovascular diseases
within 3 hours of occurrence [44], making possible intravenous
treatments based on active revascularization for acute cerebral
infarction. Before interventional neuroradiology, the effectiveness
of revascularization was suggested by researchers [45, 46]. This
treatment was not generally adopted quickly because of the limited
number of physicians and facilities capable to provide it. Regardless
of the time constraints and various treatment adaptation rules of rt-
PA intravenous therapy, this treatment spread quickly as it enabled
intravenous treatments.

2.3.5.2 Revascularization

In recent years some limitations of rt-PA were discovered bringing
interventional neuroradiological treatments to the spotlight again.
Merci is a guiding catheter with a balloon attached to it. When
inserted it enables momentary blood low interruption for thrombus
extraction using a specialized coiled wire (Fig. 2.14). This treatment