Brain Aneurysm Treatment

What is a Brain Aneurysm?

A brain aneurysm, also called a cerebral or intracranial aneurysm, is an abnormal bulging outward of one of the arteries in the brain. It is estimated that up to one in 15 people in the United States will develop a brain aneurysm during their lifetime.¹

Brain aneurysms are often discovered when they rupture, causing bleeding into the brain or the space closely surrounding the brain called the subarachnoid space. This bleeding is called a subarachnoid hemorrhage. Subarachnoid hemorrhage from a ruptured brain aneurysm can lead to a hemorrhagic stroke, brain damage and death.

The main goals of treatment once an aneurysm has ruptured are to stop the bleeding, minimize potential permanent damage to the brain and reduce the risk of another rupture. Unruptured brain aneurysms are sometimes treated to prevent them from rupturing.

Incidence Rates of Brain Aneurysms

• The annual incidence of aneurysmal subarachnoid hemorrhage in the U.S exceeds 30,000. Ten to 15 percent of these patients will die before reaching the hospital and over 50 percent will die with in the first thirty days after rupture. Of those who survive, about half suffer some permanent neurological deficit.¹
• Brain aneurysms can occur in people of all ages, but are mostly commonly detected in those ages 35 to 60. ¹
• Women are more likely to get a brain aneurysm than men, with a ratio of 3:2.¹

Treatment of Brain Aneruysms

Treatment of Brain Aneurysms
Surgery or minimally-invasive endovascular coiling techniques can be used in the treatment of brain aneurysms. It is important to note, however, that not all aneurysms are treated at the time of diagnosis or are amenable to both forms of treatment. Patients should consult a neurovascular specialist to determine if they are candidates for either treatment.

Surgical Treatment
To get to the aneurysm, surgeons must first remove a section of the skull, a procedure called a craniotomy. The surgeon then spreads the brain tissue apart and places a tiny metal clip across the neck of the aneurysm to stop blood flow into the aneurysm. After clipping the aneurysm, the bone is secured in its original place, and the wound is closed.

Minimally-invasive Treatment
Coil Embolization or Endovascular Coiling
Endovascular therapy is a minimally invasive procedure that accesses the treatment areas from within the blood vessel. In the case of an aneurysm, this treatment is called coil embolization, or "coiling." In contrast to surgery, endovascular coiling does not require open surgery. Instead, physicians use 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 insertion of a catheter (small plastic tube) into the femoral artery in the patient’s left leg and navigating it through the vascular system, into the head and into the aneurysm. Tiny platinum coils are threaded through the catheter and deployed into the aneurysm with the intent of blocking blood flow in to the aneurysm to prevent rupture. The coils are made of platinum so that they can be visible via X-ray and be flexible enough to conform to the aneurysm shape. This endovascular coiling, or filing, of the aneurysm is called embolization and can be performed under general anesthesia or light sedation. More than 125,000 patients worldwide have been treated with detachable platinum coils

Endovascular Coiling vs. Surgical Clipping
Treatment of Ruptured Aneurysms
The only mulit-center prospective randomized clinical trial, considered the gold-standard in study design, comparing surgical clipping and endovascular coiling of ruptured aneurysm is the International Subarachnoid Aneurysm Trial ISAT.

The study found that, in patients equally suited for both treatment options, endovascular coiling treatment produces substantially better patient outcomes than surgery in terms of independent survival at one year. The relative risk of death or dependence at one year for patients treated with coils was 23.9 percent lower than in surgically-treated patients.²

The study results were so compelling that the trial was halted early because that trial steering committee determined it was no longer ethical to randomize patients to neurosurgical clipping. Long-term follow-up will be essential to asses the durability of the substantial early advantage of endovascular coiling over conventional neurosurgical clipping for the treatment of brain aneurysm.

It is important that patients enrolled in ISAT were evaluated by both a neurosurgeon and an endovascular coiling specialist, and both physicians had to agree that the aneurysm was treatable by either technique. This study provides compelling evidence that, if medically possible, all patients with ruptured brain aneurysm should receive an endovascular consultation as part of the proto9col for the treatment of brain aneurysm.

Treatment of Unruptured Aneurysms
Although no multi-center randomized clinical trial comparing endovascular coiling and surgical treatment of unruptured aneurysm has yet been conducted, retrospective analyses have found that endovascular coiling is associated with less risk of bad outcomes, shorter hospital stays and shorter recovery times compared with surgery. These results should be seen as preliminary, the magnitude of difference and current predominance of surgery appear to justify a randomized trial. Studies have shown that:

• Average hospital stays are more than twice as long with surgery as compared to endovascular treatment.⁴
• Four times as many surgical patients report new symptons or disability after treatment (mean 3.9 years post procedure) as compared to coiling patients.³
• There can be dramatic difference in recovery times. One study showed that 50% of surgically-treated patients had a recovery time of one year compared to coiled patients who recovered in 27 days.³

References

1. Molyneuz A., Kerr R., Stratton I., Sandercock P., Clarke M., Shripmton J., & Holman R. (2005) International subarachnoid aneurysm trial (ISAT) of neurosurgical clipping versus endovascular coiling in 2143 patients with ruptured intracranial aneurysms; a randomized comparison of effects on survival, dependency, seizures, rebleeding, subgroups, and aneurysm occlusion, The Lancet, 366:809-17
2. Johnson SC, et al. Surgical and Endovascular Treatment of Unruptured Cerebral Aneurysms at University Hospitals. Neurology. 1999: 52:1999-1802.
3. Johnson, SC, et al. endovascular and Surgical Treatment of Unruptured Cerebral Aneurysms: Comparison of Risks, Ann Neurology. 200; 48:11-19.
4. The University Hospital. The Stroke Center. Online. Internet. University of Medicine & Dentistry of New Jersey. http://www.theuniversityhospital.com/stroke/stats.htm