Hiroaki Neki

Dr. Hiroaki Neki

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Research Focus & Metrics

Academic Career Length

19Years (2008-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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24 September 2015 in American Journal of Neuroradiology
Verified
Journal Article
Open access
PDF file
JCJ. Caroff
J. Caroff
HNHiroaki Neki
Hiroaki Neki
CMCristian Mihalea
Cristian Mihalea
FDFrancesco D’Argento
Francesco D’Argento
HKH. Abdel Khalek
H. Abdel Khalek
LSL. Spelle
L. Spelle
BACKGROUND AND PURPOSE: The flow-diverter stent has been proved a feasible, safe, and efficient technique, particularly for the treatment of large and broad-neck carotid siphon aneurysms. Wide-neck bifurcation aneurysms remain, in some cases, a challenge for neurointerventionalists. We report the outcomes of the treatment of saccular middle cerebral artery bifurcation aneurysms with flow diversion in our institution. MATERIALS AND METHODS: From the institution data base, all saccular, nondissecting MCA bifurcation aneurysms, treated with flow-diverter stents, were retrospectively reviewed. Technical issues, immediate posttreatment and follow-up angiographic findings, and clinical outcomes were assessed. RESULTS: Fourteen patients with 15 aneurysms were included in the study. Ischemic complications, as confirmed by MR imaging, occurred in 6 patients (43%). Procedure-related morbidity and mortality at last follow-up were 21% and 0%, respectively. Angiographic follow-up was available for 13 aneurysms, with a mean follow-up of 16 months. Complete occlusion was obtained for 8 aneurysms (62%). CONCLUSIONS: Compared with other available therapeutic options, the flow-diverter stent does not appear to be a suitable solution for the treatment of saccular MCA bifurcation aneurysms.

27 January 2017 in Journal of NeuroInterventional Surgery
Verified
Journal Article
Closed access
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HNHiroaki Neki
Hiroaki Neki
SKShinya Kohyama
Shinya Kohyama
TOToshihiro Otsuka
Toshihiro Otsuka
AYAzusa Yonezawa
Azusa Yonezawa
SIShoichiro Ishihara
Shoichiro Ishihara
FYFumitaka Yamane
Fumitaka Yamane
Background Aneurysmal recanalization is a problem with endovascular coiling and one of its risk factors is the low volume embolization ratio (VER). The first coil VER (1st VER) is believed to be critical for obtaining a high VER. The main objective of this study was to evaluate factors potentially useful for selecting the optimal 1st VER for endovascular coiling. Methods 609 initial saccular aneurysmal treatments performed between January 2010 and December 2014 at our institution were included in this retrospective study. Attempted procedures, retreatment cases, intraoperative rupture cases, and stent-assisted coiling cases were excluded. Age, sex, aneurysm location, ruptured aneurysm, aneurysm shape, neck size, maximum aneurysm size, dome-to-neck ratio, aneurysm volume, procedure, immediate Raymond scale score, 1st VER, and VER between the recanalization groups and non-recanalization groups were compared. Results The factors related to recanalization were ruptured aneurysms, neck width, maximum aneurysm size, aneurysm volume, procedure, 1st VER, and VER. The cut-off values for aneurysm recanalization were a 1st VER of 10.0% and a VER of 33.0%. The maximum average VER of normal size aneurysms was found in the groups with a 1st VER of 17.5–20.0%. Conclusions 1st VER was found to be a helpful index for estimating aneurysmal recanalization after coil embolization. The target 1st VER was 17.5–20.0% for obtaining a higher VER and avoiding recanalization.

23 December 2021 in Interventional Neuroradiology
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Journal Article
Closed access
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HNHiroaki Neki
Hiroaki Neki
TKTakehiro Katano
Takehiro Katano
TMTakuma Maeda
Takuma Maeda
ASAoto Shibata
Aoto Shibata
HKHiroyuki Komine
Hiroyuki Komine
YKYuichiro Kikkawa
Yuichiro Kikkawa
Achieving rapid and complete reperfusion is the ultimate purpose for ischemic stroke with large vessel occlusion (LVO). Although mechanical thrombectomy (MT) had been a proverbially important procedure, medium vessel occlusion (MeVO) with thrombus migration can sporadically occur after MT. Moreover, the safe and effective approach for such had been unknown. We reported thrombolysis with intraarterial urokinase for MeVO with thrombus migration after MT. We included 122 patients who were treated by MT with LVO stroke at our institution between April 2019 and March 2021. Of 26 patients (21.3%) who developed MeVO with thrombus migration after MT, 11 (9.0%) underwent additional MT (MT group) and 15 (12.3%) received intraarterial urokinase (UK group). The procedure time; angiographically modified Treatment in Cerebral Ischemia Scale (mTICI); functional independence, which was defined as modified Rankin Scale 0–2, on day 30 or upon discharge; and symptomatic and asymptomatic intracerebral hemorrhage (ICH) were compared between the UK and MT groups. The procedure time, mTICI, and asymptomatic ICH did not significantly differ between the groups. In the UK group, 8 of 15 (53.3%) patients obtained functional independence, and the functional independence rate was significantly higher in the UK group than in the MT group (p < 0.05). Symptomatic ICH did not occur in the UK group, and its incidence was significantly smaller than that in the MT group (p < 0.05). The results of this study suggest that intraarterial urokinase for MeVO with thrombus migration after MT may safely improve angiographic reperfusion.

1 January 2011 in Neurologia medico-chirurgica
Verified
Journal Article
Closed access
RKRyuzaburo Kanazawa
Ryuzaburo Kanazawa
SIShoichiro Ishihara
Shoichiro Ishihara
HNHiroaki Neki
Hiroaki Neki
MOMai Okawara
Mai Okawara
HIHideaki Ishihara
Hideaki Ishihara
ASAkira Sato
Akira Sato
A 44-year-old man presented with traumatic aneurysm of the left ophthalmic artery. The first coil embolization intervention achieved relatively tight packing of the aneurysm and the parent artery. After 5 months, a second embolization procedure was required because of recurrence of the aneurysm with transition of the intraaneurysmal coil formation. No recurrence occurred after the second embolization. We thought that the first embolization might have prevented catastrophic rupture, whereas the second embolization resulted in complete obliteration of the aneurysm. No entity of the aneurysmal wall formation of the current traumatic aneurysm in the acute stage may have resulted in the recanalization of the aneurysm followed by the second intervention. The stability of the wall in the chronic stage may correlate with the complete obliteration.

7 September 2023 in World Neurosurgery
Verified
Journal Article
Closed access
HNHiroaki Neki
Hiroaki Neki
YMYuichi Mochizuki
Yuichi Mochizuki
YKYoshinobu Kamio
Yoshinobu Kamio
KKKazuhiko Kurozumi
Kazuhiko Kurozumi

19 September 2020 in Neurosurgical Review
Verified
Journal Article
Closed access
PDF file
HNHiroaki Neki
Hiroaki Neki
ASAoto Shibata
Aoto Shibata
HKHiroyuki Komine
Hiroyuki Komine
SKShinya Kohyama
Shinya Kohyama
FYFumitaka Yamane
Fumitaka Yamane
YKYuichiro Kikkawa
Yuichiro Kikkawa