The Comprehensive Stroke Center at University Hospital
Treating Acute Hemorrhagic Stroke
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 and protocols.
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" (R)|
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 route.
|Coiling 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 variation.
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 medical condition.
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 coiling.
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 halted early.
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.