Three-dimensional digital subtraction angiographic evaluation of aneurysm remnants after clip placement

Abstract

Objective: The aneurysm remnants rate was evaluated via three-dimensional digital subtraction angiography (3D-DSA) in the postoperative evaluation of clipped aneurysms.

Methods: Data on surgically clipped aneurysms of anterior circulation obtained via postoperative 3D-DSA from February 2007 to March 2009 were gathered. The results of the postoperative 3D-DSA and of two-dimensional digital subtraction angiography (2D-DSA) for the detection of aneurysm remnants were compared, and an investigation was performed as to why 2D-DSA had missed some aneurysm remnants that were detected in the 3D-DSA. Various surgical factors that revealed aneurysm remnants in the 3D-DSA were also evaluated.

Results: A total of 39 neck remnants of 202 clipped aneurysms (19.3%) were confirmed in 3D-DSA, and these were classified according to Sindou's classification of aneurysm remnants. Patients with only a neck remnant found in the 3D-DSA represented 17.3% (35/202 aneurysms) of the whole series, and those with a residuum of neck plus sac found in the 3D-DSA represented 1.9% (4/202 aneurysms). The causes of aneurysm remnants were no full visualization (14/39, 35.9%), parent and perforator artery protection (10/39, 25.6%), clip design problems (8/39, 20.5%), and broad-necked aneurysm (7/39, 17.9%).

Conclusion: Patients with </= 2 mm aneurysm remnants showed an increased risk of undetectable aneurysm remnants in the 2D-DSA. The most frequent location of the missed aneurysm in 2D-DSA was the anterior communicating artery. 3D-DSA showed more aneurysm remnants than what is indicated in the existing literature, the 2D-DSA.

Keywords: Aneurysm; Clipping; Digital subtraction angiography; Remnant.

Fig. 1

A 59-year-old man harbored an aneurysm on the right middle cerebral artery bifurcation, which has been clipped and reinforced with cottonoid wrapping. A : Preoperative muti-slice computerized tomographic angiography shows a borad-necked saccular aneurysm (arrow). B : Postoperative 2D-DSA is performed 78 days after surgical clipping. 2D-DSA shows no remnant (arrow). C : Postoperative 3D-DSA is performed on the same day, and it shows remnant (arrows) (arrowhead: right M1). D : On the operative field, bulging portion below clip is shown but lumen stenosis and wide neck held complete clipping. The bulging portion is wrapped with cottonoid after clipping. The remnants size was 1.8×1.1 mm².

Fig. 2

A 52-year-old man with a residual neck after clipping of an anterior communicating artery (ACoA) aneurysm due to perforating artery arising from the aneurysm sac. A : Preoperative multi-slice computerized tomographic angiography shows a saccular aneurysm (arrow) on ACoA. B : Perforating arteries (arrows) arising from the aneurysm sac (arrowhead) are demonstrated in the operative photograph. C : Postoperative 2D-DSA is performed 20 days after surgical clipping. The remnant is not visible. D and E : Unlike 2D-DSA, 3D-DSA shows a small and residual remnant (arrow). The remnant size is 1.9×0.5 mm².