Pipeline Embolization Device for Large/Giant or Fusiform Aneurysms: An Initial Multi-Center Experience in Korea

Abstract

Purpose: The purpose of this study was to assess the safety and early outcomes of the Pipeline device for large/giant or fusiform aneurysms.

Materials and methods: The Pipeline was implanted in a total of 45 patients (mean age, 58 years; M:F=10:35) with 47 large/giant or fusiform aneurysms. We retrospectively evaluated the characteristics of the treated aneurysms, the periprocedural events, morbidity and mortality, and the early outcomes after Pipeline implantation.

Results: The aneurysms were located in the internal carotid artery (ICA) cavernous segment (n=25), ICA intradural segment (n=11), vertebrobasilar trunk (n=8), and middle cerebral artery (n=3). Procedure-related events occurred in 18 cases, consisting of incomplete expansion (n=8), shortening-migration (n=5), transient occlusion of a jailed branch (n=3), and in-stent thrombosis (n=2). Treatment-related morbidity occurred in two patients, but without mortality. Both patients had modified Rankin scale (mRS) scores of 2, but had an improved mRS score of 0 at 1-month follow-up. Of the 19 patients presenting with mass effect, 16 improved but three showed no changes in their presenting symptoms. All patients had excellent outcomes (mRS, 0 or 1) during the follow-up period (median, 6 months; range, 2-30 months). Vascular imaging follow-up (n=31, 65.9%; median, 3 months, range, 1-25 months) showed complete or near occlusion of the aneurysm in 24 patients (77.4%) and decreased sac size in seven patients (22.6%).

Conclusion: In this initial multicenter study in Korea, the Pipeline seemed to be safe and effective for large/giant or fusiform aneurysms. However, a learning period may be required to alleviate device-related events.

Keywords: Aneurysm; Flow diverter; Pipeline.

Figures

Fig. 1. A 51-year-old woman with bilateral distal internal carotid artery aneurysms.

A, B. Frontal projection and 3-D reconstruction images show a large aneurysm at the intradural para-ophthalmic segment of the right internal carotid artery. The asterisk indicates a coil-embolized aneurysm at the left distal internal carotid artery. The asterisk indicates the coil embolized aneurysm of left internal carotid artery. C. Angiogram after Pipeline implantation shows markedly decreased flow into the aneurysm sac. D. A flat-panel CT image shows incomplete expansion of the distal portion of the Pipeline resulting in poor wall apposition (arrow). E. After ballooning for wall apposition of the Pipeline, the distal end (arrowhead) of the pipeline was partially herniated into the aneurysm sac, resulting in alleviation of the flow diversion effect. F. A spot image after the second Pipeline implantation in a telescopic manner. Note the waist of the second Pipeline at the distal end (arrowhead) of the first Pipeline, which partially herniated into the sac. G. After using a balloon for the apposition of the second Pipeline, the aneurysm sac was no longer visualized. The arrowhead indicates the distal end partially herniated into the sac. H. A flat-panel CT image showing that a mild degree of the waist of the second pipeline still remained at the end of the first pipeline. Note the twisted struts (arrows) at the waist point. I. The 6-month follow-up angiogram shows a severe degree of in-stent stenosis, even though the patient remained asymptomatic. The left anterior cerebral artery was supplied via the anterior communicating artery from the left internal carotid artery (not shown). J. The 12-month follow-up angiogram shows improvement of the in-stent stenosis.

Fig. 2. A 67-year-old woman presenting with third and sixth cranial nerve palsies and a recently aggravated intractable headache.

A. The coronal MIP reconstruction image of the CT angiogram shows a giant aneurysm at the left internal carotid artery, cavernous segment. Note that the left distal internal carotid and middle cerebral arteries were tented (arrow) due to mass effect from the aneurysm. B. A lateral projection angiogram shows a giant aneurysm at the left internal carotid, cavernous segment. C. Final control angiogram after the pipeline implantation shows marked flow diversion with contrast material stagnation in the aneurysm sac. D. A source image of the 3-month follow-up CT angiogram shows that the aneurysm was completely thrombosed. The bulging contour of the left cavernous sinus (arrowheads) remained due to the thrombosed aneurysm. E, F. The source (E) and coronal MIP reconstruction (F) images of the 6-month follow-up CT angiogram show that the thrombosed aneurysm disappeared and that the left internal carotid artery was patent. Note that the left distal internal carotid and middle cerebral arteries were normal-positioned without tenting (arrow).