Biomedical Engineering Reference
In-Depth Information
of fatality from 32% to 67% after the hemorrhage [2, 3]. Morbidity rates reach
10
.
9% due to intra cranial bruise, subsequent recurrent bleeding, hydrocephaly
and spasms in the surrounding brain vessels [4].
5.1.2
Planning Endovascular Interventions
The treatment of cerebral aneurysms aims at their complete elimination from the
circulation. The traditional surgical technique consists in clipping the aneurysm.
In the case of subarachnoid hemorrhage (SAH), early management prevents re-
bleeding and future rupture. More concretely, it has been observed that an early
treatment of the aneurysm reduces the risk of SAH, mortality and morbidity [5].
Nevertheless, the risk of lesions during the intervention is still high in surgically
unfavorable locations.
In the past years, there has been a growing trend to practise minimally in-
vasive endovascular procedures to treat cerebral aneurysms [6]. In cases of
potential aneurysm rupture, these techniques stabilize the patient and facili-
tate further aggressive treatments with the purpose of preventing the spasm
after intra-cerebral bleeding. Aneurysm coiling with Guglielmi detachable coils
(GDC) is probably the most widespread technique for permanent aneurysm
embolization. The placement of coils inside the aneurysm promotes blood clot-
ting by electrothrombosis, thus avoiding blood flow and pressure, and ham-
pering its rupture [7]. Figure 5.3 shows a picture of a GDC, and two digi-
tal substraction angiographies of a brain aneurysm before and after patient
embolization.
A correct size selection and placement of the GDC inside the aneurysm is
crucial for the success of the treatment, for which it is highly desirable to have
pre-surgical knowledge of the dimensions as well as from the three-dimensional
morphology of the aneurysm and connected vessels. For example, the amount
of aneurysm filling following the coiling is strongly dependent on the geometry
and dimensions of the aneurysm. In particular, it has been shown that knowl-
edge about the maximum neck diameter and the main axes dimensions of the
aneurysm, dome width and depth, play an important role in the selection of
patients and materials for an appropriate treatment with GDCs [8]. Figure 5.4
shows the traditional measurements used for the planning of the endovascular
procedures.
