Long-term Follow-up Results after Flow Diverter Therapy Using the Pipeline Embolization Device for Large or Giant Unruptured Internal Carotid Artery Aneurysms: Single-center Retrospective Analysis in the Japanese Population

Abstract

Flow diverter (FD) therapy using Pipeline embolization device (PED) has become an important alternative to treat internal carotid artery (ICA) aneurysms. Herein, we report the long-term outcome for 3 years after FD therapy using PED for ICA aneurysms in Japan. The patients who underwent angiographical and/or clinical follow-up for 3 years after the FD therapy using PED of large or giant unruptured ICA aneurysms from December 2012 at our university hospital are the subjects of this study. We retrospectively reviewed the in-and outpatients' medical charts, and written operative and radiological records. There were 84 patients with 90 aneurysms who could be clinically and/or angiographically followed up for 3 years. Of these, 7 aneurysms were only available for clinical follow-up. Of the remaining 83 aneurysms, 6 aneurysms had vessel occlusion due to stent thrombosis or parent artery occlusion, and 60 of the remaining 77 (77.9%) had complete occlusion. In multivariate analysis, older age (>70 years), wide neck, and non-adjunctive coiling contributed statistically significantly to incomplete occlusion. Of the 84 patients, 2 patients (2.4%) had delayed complications between 6 months and 3 years after the initial FD placement. Three patients (3.6%) had poor outcome due to postoperative major stroke complications, 2 of which were acute complications. The long-term results after FD therapy are good both angiographically and clinically. Endothelialization of the aneurysmal neck and intra-aneurysmal thrombosis contribute to complete occlusion. The primary reason for the somewhat low complete occlusion in Japan may be the patients are generally older.

Preliminary Experience of the Surpass Streamline Flow Diverter for Large and Giant Unruptured Internal Carotid Artery Aneurysms

“…Fujii et al reported that elderly patients were a risk factor of poor aneurysm occlusion with the PED. 5 ) In the present series, nine patients 65 years or older had a low CO rate (33.3%). On the other hand, 11 patients younger than 65 years had a high CO rate (81.8%).…”

“…Recently, flow diverter (FD) therapy has become an important alternative endovascular strategy for large or giant unruptured intracranial aneurysms. [2][3][4][5] Although various FDs made of different materials and with different delivery systems are available worldwide, there are currently three commercially available flow diverters in Japan, namely, the Pipeline Flex (Medtronic, New York, NY, USA), the FRED (Terumo, Tokyo, Japan), and the Surpass Streamline (SS) (Stryker, Tokyo, Japan). The SS is the newest in Japan that was most recently approved in January 2021.…”

Onset-to-treatment time and aneurysmal regression predict improvement of cranial neuropathy after flow diversion treatment in patients with symptomatic internal carotid artery aneurysms

“…After 12 months, this proportion decreased slightly because of symptom worsening in two patients with a partially occluded aneurysm that had recurred or enlarged. Previous studies have reported that the occlusion rate increases over the first 12 months in aneurysms treated using flow diversion, but not much after that time 18 19. Considering all the above, additional treatment may be advisable for patients treated with flow diversion who do not experience improvement in cranial neuropathy and aneurysm occlusion within the first 12 months of treatment.…”

Flow diversion for compressive unruptured internal carotid artery aneurysms with neuro-ophthalmological symptoms: a systematic review and meta-analysis

“…Literature search was performed on March 21, 2022. After removal of duplicates and screening of titles and abstracts, we sought for the original articles of 82 publications 7 13–93. After completion of literature review and data extraction and before closing the database, the literature search was repeated on PubMed only on May 22, 2022, using the above-mentioned search string to identify additional potentially eligible articles.…”