Aneurysms pathophysiology is associated with hemodynamic stresses and inflammation of the blood vessels.
The main changes present in the wall of the vessels are: thinning of the media,
decrease of the vascular smooth muscle cells and the loss of collagen synthesis.
All of these factors induce the wall weakness which is the direct cause of aneurysms formation.
Arterial bifurcations are the most frequent locations of cerebral aneurysms.
The following imagine shows aneurysms most common placements in the Circle of Willis
Fig. 1: Circle of Willis
References: Jan Piechota
The incidence of cerebral aneurysms is not exactly known.
According to various studies,
it is estimated that they occur at 0.2-7.9% of the human population.
The majority of which (88%) are revealed by subarachnoid hemorrhage,
8% by the physical symptoms of a brain tumor,
4% are detected randomly.
The risk factors that are associated with the aneurysm formation include: atherosclerosis,
hypertension,
excessive alcohol consumption,
smoking,
head injuries, female sex (lower estrogen levels after menopause) and also genetic factors such as inherited connective tissue disorders.
Aneurysm rapture may lead to the subarachnoid hemorrhage (SAH).
It occurs when tension in the vessel exceeds the mechanical strength of wall tissue.
Rapid acute pain,
often radiating to the occipital region,
nausea,
vomiting,
loss of consciousness are the symptoms of the subarachnoid hemorrhage.
The most serious consequences of the SAH is the higher risk of disability and mortality.
Till 1990’s cerebral aneurysms were treated by the surgical clipping.
This procedure was often associated with a high risk of postoperative complications and a long time of hospitalization.
AnItalian interventional neuroradiologist,
Guido Guglielmi,
revolutionized the treatment of the cerebral aneurysms.
The technique is commonly used in radiologic procedures,
it allows a noninvasive access to cerebral blood vessels.
The imagine below presents the use of the method in endovascular embolization of aneurysms.
Fig. 2: Endovascular embolization with the use of detachable coils.
References: Jan Piechota
STUDY POPULATION
A group of 60 patients was qualified for endovascular treatment with the use of hydrogel coils.The average age of a patient was 53 years.
Maximum: 72,
minimal: 28.
44 women and 16 men have been treated from 01.2010 to 03.2012 year.
72 endovascular embolization procedures have been performed.
HYDROGEL COILS
Hydrogel coils were created to increase the effectiveness of cerebral aneurysm embolization.
Achieving high packing density of coils in the sac of aneurysm decrease the risk of reoccurrence.
The coils are made of hydrogel material wrapped around platinum coil.
In a blood vessel,
due to water absorption,
hydrogel material swells up and the coil expands in diameter (in 20 minutes,
the diameter is increased 3 times).
EMBOLIZATION PROCEDURE
Before embolization all patients were diagnosed with the use of DSA (digital substraction angiography) of cerebral vessels with rotational scanning.
Angiograms were analyzed in a specialized workstation Phillips Integris 3D RA.
It allowed us to get 3D reconstructions of cerebral arteries.
Fig. 3: 3D reconstructions of cerebral arteries.
References: Department of Radiology, Samodzielny Publiczny Centralny Szpital Kliniczny im. Prof. Kornela Gibinskiego Slaskiego Uniwersytetu Medycznego
Fig. 4: 3D reconstructions of cerebral arteries.
References: Department of Radiology, Samodzielny Publiczny Centralny Szpital Kliniczny im. Prof. Kornela Gibinskiego Slaskiego Uniwersytetu Medycznego
Angiography was performed with the use of the Seldinger’s method.
First,
a large artery needs to be punctured (femoral,
axilar or brachial artery) with a use of a special needle (trocar),
which allows to introduce a flexible guidewire into the lumen of a vessel.
Then,
the needle is removed and catheter is passed over the guide wire into the artery.
After that,
the guide wire is removed.
The external end of the catheter is connected to an automatic syringe.
It allows to inject radiocontrast in to the lumen of the vessel and visualize cerebral aneurysms.
Later a microguidewire is passed over the catheter into the sac of the aneurysm.
Finally coils are introduced into the aneurysm (number depends on its diameter).
After the embolization another DSA images are taken to confirm the aneurysm obliteration.
Fig. 5
References: Department of Radiology, Samodzielny Publiczny Centralny Szpital Kliniczny im. Prof. Kornela Gibinskiego Slaskiego Uniwersytetu Medycznego
Fig. 6
References: Department of Radiology, Samodzielny Publiczny Centralny Szpital Kliniczny im. Prof. Kornela Gibinskiego Slaskiego Uniwersytetu Medycznego
Patients 1.
DSA images taken during the embolization.
Angiogram on the top presents the cerebral aneurysm before embolization,
on the second picture we can see the same aneurysms obliterated.
Fig. 7
References: Department of Radiology, Samodzielny Publiczny Centralny Szpital Kliniczny im. Prof. Kornela Gibinskiego Slaskiego Uniwersytetu Medycznego
Fig. 8
References: Department of Radiology, Samodzielny Publiczny Centralny Szpital Kliniczny im. Prof. Kornela Gibinskiego Slaskiego Uniwersytetu Medycznego
Patients 2.
DSA images taken during the embolization.
Angiogram on the top presents the cerebral aneurysm before embolization,
on the second picture we can see the same aneurysms obliterated.
In the case of the embolization of aneurysms with a wide neck,
we used a vessel stent to remodel the wall of the vessel so that the coil can stay on the right position.
During this study we performed 21 embolizations (35%) with a use of vessel stents.
Images below show virtual stent implantation.
Fig. 9: 3D reconstruction and virtual stent implantation.
References: Department of Radiology, Samodzielny Publiczny Centralny Szpital Kliniczny im. Prof. Kornela Gibinskiego Slaskiego Uniwersytetu Medycznego
Fig. 10: 3D reconstruction and virtual stent implantation.
References: Department of Radiology, Samodzielny Publiczny Centralny Szpital Kliniczny im. Prof. Kornela Gibinskiego Slaskiego Uniwersytetu Medycznego