Keywords:
Interventional vascular, Neuroradiology brain, Catheter arteriography, Embolisation, Arteriovenous malformations
Authors:
H. Kiyosue1, S. Tanoue1, J. Kashiwagi2, H. Mori2; 1YUFU/JP, 2Oita/JP
DOI:
10.1594/ecr2013/C-2570
Conclusion
Endovascular treatment,
including transarterial embolization and transvenous embolization,
has become the first-line option for the treatment of most cases of intracranial DAVFs.
Recent reports of transarterial embolization using liquid embolic materials such as ONYX and glue showed high curative rates of DAVFs especially for Cognard’s type IIb and type III DAVFs (7) (8).
However,
serious complications including cranial nerve injury,
distal migration,
and embolization of cerebral arteries due to migration of glue via the dangerous anastomosis have also been reported (9-11).
Therefore,
it is very important to evaluate the feeding arteries and the fistulous points for avoiding such complications.
Transvenous embolization is an effective technique for the treatment of sinusal DAVFs especially for cavernous sinus DAVFs.
Sinus packing with coils has been used as a standard technique for the treatment of sinusal DAVFs.
Recently,
several authors demonstrated effectiveness of selective transvenous embolization of the shunted pouches for the selected cases (12) (13).
Evaluation of the fistulous points,
shunted pouches and small draining vein is required for transvenous embolization.
Serious complication such as cerebral hemorrhage can occur during and after transvenous embolization when the DAVFs remain with retrograde drainage via a small cerebral vein (14) (15).
Therefore,
evaluation of their angioarchitechtures including feeding arteries,
shunted pouches,
and draining veins before treatment is very important for successful results.
Biplane DSA has been use as a gold standard technique for evaluating angioarchitectures and hemodynamics of DAVFs.
However,
2D DSA of carotid artery cannot clearly demonstrate the angioarchitectures in some cases due to overlapping of numerous vessels enlarged due to arteriovenous shunt.
It has been reported that CT-like images reconstructed from a data set of rotational digital angiography are useful for evaluating these angioarchitectures (3) (4). Hiu et al.
demonstrated the superiority of CT-like images to 2D-DSA in assessing these angioarchitectures of DAVFs (4).
However,
it would be sometime difficult to evaluate small vessels running adjacent to or within the bony structure due to similar density of the enhanced vessels and bone.
In our results,
3D fusion images were superior to 3D-digital angiography (CT-like images) for evaluating angioarchitectures of DAVFs in a majority of case.
3D fusion images showed much better results especially for depiction of a small transosseous feeders or small feeders running very close to the thick bone (eq.petrosal bone).
MIP and/or MPR reconstructed images from single dataset of rotational DSA (3D-DSA) can demonstrate these small branches,
while orientation and identification of these branches are more difficult due to lack of osseous images.
Recently,
a report describing a technique of 3D fusion images between data sets of mask images and DSA images during rotational DSA (16).
However,
clinical efficacy of the 3D fusion images has not been reported.
In our technique of 3D fusion images,
we fused datasets of nonsubtructed and subtracted digital angiography.
This technique can enhance the vascular structure more than the fusion image obtained from datasets of mask images and rotational DSA,
and therefore tiny vascular structure can be visualized.
In our clinical experiences,
pretherapeutic evaluation of the angioarchitectures of DAVFs using the 3D-fusion images is very useful for endovascular treatment.
For transarterial embolization,
dangerous feeder and potential anastomoses could be identified well and easily grasped by 3D fusion images.
For transvenous embolization,
small shunted pouches could be preciously depicted,
and it was useful for selective embolization of these shunted pouches.
In our series,
small vessels could not be well visualized due to motion artifact in one patient with conscious disturbance.
Because DSA based data is used in this technique,
patient’s motion during obtaining mask data and angiographic data spoil the image quality.
It is one limitation of this technique.
In conclusion,
fusion images of non-subtracted and subtracted rotational angiography are useful for pretherapeutic evaluation of angioarchitectures of intracranial DAVFs.