Angiograph of an aneurysm in a cerebral artery. An estimated six million Americans harbor an aneurysm. Aneurysms occur when artery walls are weakened, causing a saclike bulge in the blood vessel. People can live symptom free with aneurysms, but if one grows big enough and ruptures, it will be fatal 40 percent of the time. Even if someone survives a ruptured aneurysm, the patient will most likely suffer permanent neurological damage and/or disabilities.

Current treatment protocols for aneurysms focus on preventing the rupture of the aneurysm via blocking blood flow to the bulge. The first treatment option was surgical clipping, which was introduced in 1937 by Walter Dandy. Surgical clipping required the opening of the brain and placing a clip at the base of the aneurysm. This clip prevents blood from entering the aneurysm. Although this procedure is quite invasive, the benefit is that there is a low reoccurrence rate with this technique.

The other popular option for aneurysm treatment is endovascular coiling. This less invasive procedure involves insertion of a catheter through the groin to place platinum coils at the aneurysm. These coils block blood flow into the area, thus, preventing rupture. While coiling is less invasive than surgical clipping, reoccurrence in the first year occurs in 28.6 percent of patients and increases over subsequent years.

While current treatment options prevent rupture, clear limitations to their feasibility and long-term success exist. New research focuses on improving the treatment of aneurysms. These treatments aim to not just block the growth of the aneurysm, but to actually restructure the blood vessel back to a normal state.

An alternative to coiling is the Piperline Embolization Device. Similar to coiling this technique is minimally invasive and is inserted via a catheter. Rather than filling the aneurysm with coils, however, this device provides a scaffold within the artery that restructures the vessel. The blood left in the bulge clots, preventing rupture and over time may potentially actually result in the shrinking of the aneurysm. Furthermore, this procedure appears to work on wide necked aneurysms (where the buldge has a wide connection to the blood vessel), which don’t do well with clipping or coiling.

Nanotechnology is also posited to improve treatment of aneurysms with stents. The coating of stents with nanomaterials could result in the attraction of cells to restructure the area (see the diagram below). For cells to move into an area, researchers are using both textural and chemical cues. Understanding the optimal environment for cell regeneration allows for the coating of stents with materials that attracts cells. As cells move in to the area, they can begin to repair the surface of the blood vessel. Ideally this would result in a restructured blood vessel, which would act as a permanent solution.

Current treatments for brain aneurysms aim to prevent the rupture of the aneurysm, but they do not actually remove the aneurysm. This means that the aneurysm can reoccur, although this is less likely with the more invasive clipping. Furthermore, these techniques are limited in their ability to treat certain types of aneurysms such as wide necked aneurysms. Current research focuses on not just preventing rupture, but actually restructuring the blood vessel.

This diagram illustrates the concept behind a new type of "bioactive" coating for stents used to treat brain aneurysm.