Cerebral aneurysms are a disorder of cerebral blood vessels where a weakness in an arterial wall leads to focal dilatation or ballooning of the vessel. Cerebral aneurysms are a common condition, and have been found in anywhere between 1 to 5% of the general population. Of those patients found to have a cerebral aneurysm, multiple aneurysms may be present in up to 20% of cases.
Risks factors for the development and rupture of cerebral aneurysms include female gender, family history of cerebral aneurysms, smoking, hypertension and rare inherited genetic disorders.
Aneurysms have been classified as small (less than or equal to 6 mm), medium (7-12), large (12-24 mm) and giant (>25 mm) based on their size. Aneurysms may be found incidentally during imaging studies of the brain performed for unrelated reasons. Although most intracranial aneurysms are small, over time the aneurysm may increase in size or change in shape.
The main danger of having an aneurysm is a risk of rupture. When aneurysms rupture, it can lead to life-threatening bleeding in the brain. This type of bleeding most often occurs in the cerebrospinal fluid that surrounds the brain and is called subarachnoid hemorrhage. Patients who suffer from subarachnoid hemorrhage secondary to a ruptured cerebral aneurysm have a significant risk of permanent disability or death. Rarely, cerebral aneurysms may become large enough where they produce symptoms from mass effect and compression of adjacent structures, without associated hemorrhage.
The goal of treatment of unruptured cerebral aneurysms is to close the diseased segment of the vessel before bleeding occurs. This has traditionally been accomplished by surgical repair of the aneurysm where an experienced neurosurgeon opens the skull and places a surgical clip across the opening between the aneurysm and the artery it arises from. Additionally, endovascular repair of cerebral aneurysms is also possible, and consists of minimally invasive surgery performed entering through the artery in the groin. In this technique, a small plastic tube, or catheter, is navigated under x-ray guidance to the diseased vessel in the brain. Through this catheter, small metal threads, or coils, are then placed into the aneurysm sac, resulting in closure of the aneurysm.
Increasingly, another minimally invasive technique (flow-diversion) consists of placement of a small metal stent in the diseased artery, which over time leads to thrombosis and obliteration of the aneurysm. One such approved device is “pipeline stent” for aneurysms.
The decision as to which therapy is best for a cerebral aneurysm, open surgical repair versus endovascular treatment, is complex and depends on a host of factors including aneurysm size and location, age and general health of the patient, as well as patient preference. In addition, certain small cerebral aneurysms may be followed conservatively with non-invasive imaging if the patient has no additional risks factors for aneurysm rupture. Regardless of the management option a patient chooses, consultation and follow up with an experienced neurosurgeon or neurointerventionalist is essential to ensure appropriate care.
University of Maryland is a very high volume center for treatment of intracranial aneurysms. We have a dedicated, expert multidisciplinary neurovascular group that consists of nationally renowned endovascular specialists, neurovascular surgeons and neuro-critical care specialists.
The endovascular group has extensive experience with cutting edge treatments (pipeline, flow diversion, coiling, balloon and stent assisted embolization) for saccular as well as complex aneurysms. We participate in several research studies and will soon start a pilot multicenter trial for the treatment of small aneurysms.