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 need to 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 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 area from within the blood vessel. In the case of aneurysms, 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 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, blocking blood flow into the aneurysm and preventing 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 filling, 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. Learn more about the development of detachable platinum coil technology.

Endovascular Coiling v. Surgical Clipping

Treatment of Ruptured Aneurysms
Until recently, most studies on the surgical clipping and endovascular treatment of brain aneurysms were either small-scale studies or were retrospective studies that relied on analyzing historical case records. The only multi-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)¹ .

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 survival free of disability at one year. 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 study results were so compelling that the trial was halted early after enrolling 2,143 of the planned 2,500 patients because the trial steering committee determined it was no longer ethical to randomize patients to neurosurgical clipping. Long-term follow-up will be essential to assess the durability of the substantial early advantage of endovascular coiling over conventional neurosurgical clipping for the treatment of brain aneurysms.

It is important to note that patients enrolled in the 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 aneurysms should receive an endovascular consultation as part of the protocol for the treatment of brain aneurysms.

Treatment of Unruptured Aneurysms
Although no multi-center randomized clinical trial comparing endovascular coiling and surgical treatment of unruptured aneurysms 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. Studies have shown that:

• Average hospital stays are more than twice as long with surgery as compared to endovascular coiling treatment²
• Four times as many surgical patients report new symptoms or disability after treatment as compared to coiled patients³
• There can be a dramatic difference in recovery times. One study showed that surgically-treated patients had an average recovery time of one year compared to coiled patients who recovered in 27 days³

To find more information about clinical studies about the surgical and endovascular coiling treatment of brain aneurysms, see the clinical research section.