While there has been a virtual revolution in the treatment
of ischemic stroke thanks to the advent of tissue Plasminogen
Activator (tPA), the options for reducing the potential
for damage in hemorrhagic stroke are more limited. Nonetheless,
progress is being made here, too — especially in
the area of prevention.
In addition, new research provides compelling evidence
that patients suffering from the most fatal form of
hemorrhagic stroke have a significantly better chance
of survival when they are treated at a hospital that
sees a high volume of those types of cases. The comprehensive
study of subarachnoid hemorrhage (SAH) shows that patients
admitted to high-volume SAH centers (those that see
more than 35 cases a year) have a 40 percent better
survival rate than patients admitted to low-volume centers
(those having fewer than 10 cases a year). The authors
of the study attributed this finding, in part, to differences
in the availability of specialized personnel, equipment
Surgical clipping may be used when the stroke is caused
by a ruptured aneurysm in the subarachnoid space. It
is also used to prevent aneurysms from rupturing. The
procedure is always performed by a neurosurgeon, preferably
one with expertise in cerebrovascular disease.
|Illustration showing aneurysm clip
place around the neck of an aneurysm(L) and with
the clip in place, the aneurysm is "deflated"
In order to clip an aneurysm, the neurosurgeon first
must perform a craniotomy — a surgical procedure
in which the brain and the blood vessels are accessed
through an opening in the skull. The surgeon blocks
the blood flow into the aneurysm by applying a metal
clip to its base (neck) where it connects to the blood
vessel. This stops the hemorrhaging into the subarachnoid
space and redirects the blood flow along its proper
procedure for treating a sidewall aneurysm.
Aneurysm clips generally are made of titanium and come
in all different shapes and sizes. The choice of a particular
clip is based on the size and location of an aneurysm.
The clip has a spring mechanism which allows the two
"jaws" of the clip to close around either
side of the aneurysm, thus separating (occluding) the
aneurysm from the parent blood vessel. These clips are
designed to be left in place permanently.
This is a newer, much less invasive technique
for treating certain types of ruptured and unruptured
aneurysms. The procedure can be performed under general
anesthesia or light sedation by a neurosurgeon, an interventional
neuroradiologist, or a specially trained neurologist
using real-time X-ray technology, called fluoroscopic
imaging, to visualize the patient's vascular system
and treat the disease from inside the blood vessel.
Endovascular treatment of brain aneurysms involves
inserting a thin plastic catheter into the femoral artery
in the patient's groin and navigating it through the
vascular system into the head and into the aneurysm.
A tiny platinum coil is threaded through the catheter
and deployed into the aneurysm, blocking blood flow
into the aneurysm and preventing rupture (or re-rupture).
The coil, which is made of platinum so it can be visible
via X-ray, is flexible enough to conform to the aneurysm
shape. It is commonly referred to as the Guglielmi Detachable
Coil (or GDC® Coil) after its inventor, Guido Guglielmi,
MD, who pioneered the use of coiling technology in the
brain in the late 1980s. The Food and Drug Administration
approved it for use in the United States in 1995.
Today, more than 140 variations of the original GDC
Coil design are available in a wide range of sizes in
different delivery platforms to accommodate case-by-case
of Clipping & Coiling
There are risks of complications with both
clipping and coiling. When treating an unruptured aneurysm,
one of the most serious problems in either procedure
is rupture. Reported rupture rates range from 2 percent
to 3 percent for both coiling and clipping.
Ischemic stroke is another serious complication sometimes
encountered in both clipping and coiling. A clot could
form and dislodge from the vessel, or a normal vessel
could be blocked by the clip or coil and blood could
be prevented from flowing through.
The duration of either procedure, the associated risks,
projected recovery time and prognosis (anticipated outcome)
depend on the location of the aneurysm, the presence
and severity of hemorrhage, and the patient's underlying
vs. Surgical Clipping
Until recently, most studies comparing surgical
clipping and the endovascular treatment of ruptured
brain aneurysms were either small-scale studies or retrospective
studies that relied on analyzing historical case records.
The International Subarachnoid Aneurysm Trial (ISAT),
a multi-center prospective randomized clinical trial
— considered the gold-standard in study design
— has provided conclusive evidence favoring endovascular
The study compared surgical clipping and endovascular
coiling of ruptured aneurysms and found that, in patients
equally suited for both treatment options, coiling produces
substantially better outcomes in terms of survival free
of disability. The relative risk of death or significant
disability at one year for patients treated with coils
was 22.6 percent lower than in surgically treated patients.
The ISAT results were so conclusive that the trial was
The findings provide compelling evidence that, whenever
medically appropriate, patients with a ruptured brain
aneurysm should receive endovascular treatment. It also
underscores the importance of seeking treatment for
acute stroke at a comprehensive center, which offers
the widest range of treatment options.
No multi-center randomized clinical trial (considered
the gold standard in study design) has yet been conducted
comparing endovascular coiling and surgical treatment
of unruptured aneurysms. However, retrospective analyses
of cases involving unruptured aneuryms also suggest
that endovascular coiling is associated with reduced
risk of bad outcomes, shorter hospital stays and shorter
recovery times as compared with surgical clipping.
This treatment is used to prevent the formation
of blood clots (intracerebral hematomas) following or
as a result of hemorrhagic stroke and reduce pressure
in the cranium. Cerebrospinal fluid (CSF) is constantly
being made and drained from the brain. An infusion of
blood from a hemorrhage can interfere with the normal
drainage of CSF, causing a fluid buildup. In ventriculostomy,
a drain is inserted into the fluid spaces in the brain.
The drainage reduces pressure in the veins and reduces
the risk of second stroke or other damage.
About 20 percent of SAH patients experience
vasospasm — a narrowing of blood vessels in response
to irritation from blood accumulating in the subarachnoid
space. This makes it harder for nutrients and oxygen
to reach the rest of the brain, and if vasospasm persists
long enough, it can result in another stroke.
The condition can be treated with hypertensive hypervolemic
hemodilution therapy — commonly known as Triple
H therapy. Triple H therapy combines intravenous medications
and large volumes of intravenous fluids to elevate blood
pressure, increase blood volume, and thin the blood,
driving blood flow through and around affected vessels.
If Triple H therapy is unsuccessful, balloon angiography
may be used to open up the tight vessels.
This intervention is currently being investigated
as a treatment following severe stroke and brain hemorrhage
to prevent permanent brain damage. It involves lowering
the temperature of the brain to protect brain cells
from death due to trauma or lack of blood flow and oxygen.