Elsevier

World Neurosurgery

Volume 84, Issue 2, August 2015, Pages 520-527
World Neurosurgery

Original Article
Flat Detector Computed Tomography-Based “Dual Vessel Fusion” Technique for Diagnosis and Surgical Planning in the Management of Dural Arteriovenous Fistula

https://doi.org/10.1016/j.wneu.2015.04.020Get rights and content

Objective

To explore the value of flat detector computed tomography-based vessel fusion technique for visualizing and evaluating anatomic structures and hemodynamic features of patients diagnosed with dural arteriovenous fistulas (DAVF).

Methods

Eleven patients with DAVF were investigated. The 3-dimensional structure of the DAVF fistula point, feeding arteries, and draining veins were reconstructed from separately acquired rotational angiographic images and then displayed as a single image in a fused manner.

Results

In the vessel fusion image, the tangled cluster of vessels of the DAVF could be clearly visualized from selected optimal viewing angles in the 3-dimensional space. Each component of the DAVF fistula point with its specific artery feedings and venous drainage could be identified accurately.

Conclusions

The vessel fusion technique gave detailed anatomic information that enabled better understanding of the DAVF structure, and facilitated an accurate interventional or surgical planning.

Introduction

A dual arteriovenous fistula (DAVF) is an abnormal connection between dural arteries and dural venous sinuses, meningeal veins, or cortical veins. DAVFs comprise 10%–15% of all intracranial arteriovenous malformations 2, 8. The clinical manifestations of patients and thier treatment plans are mainly determined depending on the location and the venous drainage pattern. Most DAVFs can be managed by endovascular treatment but some are more appropriately approached by surgery. Precise identification of the anatomic structure of the DAVF, such as the feeding arteries, the draining veins, and especially the location of the fistula point, and assessment of hemodynamic features of the fistula are essential to a successful treatment. At present, there are several imaging modalities and techniques for diagnosing DAVFs such as noninvasive computed tomography angiography and magnetic resonance imaging angiography. These imaging techniques are particularly useful in localization of the arteriovenous shunt in relation to the surrounding brain tissue and skull anatomy, and are suitable for DAVF primary diagnosis and follow-up examination. However, these techniques, limited by their spatial resolutions, lead to an inadequate presentation of the detailed structure of the DAVF 1, 5, 6, 10, 14. Flat detector computed tomography (FDCT)-based cerebral digital subtraction angiography (DSA), with a resolution of 0.1–0.2 mm, remains the gold standard for complete characterization and classification of the DAVF (9). This technique involves injecting a certain amount of radiopaque contrast medium (CM) into the arteries of interest through a catheter. At the same time, 2-dimensional (2D) x-ray images are acquired for clinical observation. DAVF may have more than 1 major feeding artery, and thus, injection of all potential arteries needs to be performed to identify component that may contribute to the pathology of the region. However, DAVFs consist of numerous tiny connections between branches of dural arteries and veins or a venous sinus, with their structures varying within the 3-dimensional (3D) space. Thus, with the limited projection angles provided by the 2D DSA, an accurate assessment of the DAVF is not guaranteed, which potentially results in treatment failure. Studies have shown that FDCT-based 3D volume reconstructions, which enabled visualization from any angle, have overcome some of limitations of 2D imaging. 2D imaging limitations may include false vessel foreshortening due to an inappropriate projection angle or a vessel obscured by superimposed vessels.

This study was based on the FDCT imaging and explored the value of the state-of-the-art image postprocessing technique “dual vessel fusion” (13) to improve the visualization of the fistula point with 2 arterial feeders and to assist in treatment planning.

Section snippets

Patient Data Collection

Between August 2012 and December 2013, 11 patients (5 men and 6 women; mean age, 50.0 ± 11.9 years) were confirmed to have DAVF and were enrolled into this study. This study had been approved by the hospital ethics committee.

Image Acquisitions

Each patient received intravenous sedation plus local anesthesia. All imaging procedures were performed with a biplane FDCT system (Artis zee, Siemens Healthcare, Germany). For each patient, 2D DSA sequences were acquired after catheterization of bilateral external and

Results

Successful vessel fusion was achieved for all 11 patients. The vessel fusion image was used to accurately identify the detailed morphology and location of the DAVF. The components of the DAVF, including joint fistula point, different feeding arteries, and draining veins, could be clearly demonstrated in 1 fusion image. The treatment decision between surgery and intervention was made depending on the complexity of reaching the treatment target as well as the possibility to completely embolize

Discussion

Most DAVFs can be effectively treated by either endovascular embolization or open surgery (11). Comprehensive preoperative identification of the anatomic structure and hemodynamic features was the key to ensure an optimal treatment plan 4, 7. With selective catheterization and high pressure CM injection, DSA imaging was the first choice and remained the gold standard for visualization of DAVFs. It could precisely define the feeding arteries, the draining veins or retrograde venous drainage, and

Conclusion

In this preliminary study, we have shown the feasibility of using a dual vessel fusion technique to accurately depict the DAVF components in 3D space. The fusion image provided a comprehensive presentation of the DAVF anatomy, located the fistula point, delineated the origins of 2 feeding arteries, and draining veins. The technique enabled a better understanding on the pathologic characteristics for the clinicians and, potentially, helps to improve treatment effect and efficacy. A large scale

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Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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