Delayed Focal Stenosis and Aneurysmal Dilatation after Flow Diverter Placement Possibly Related to Distal Malapposition.
4 affiliations
- 1Department of Neurosurgery, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Nagasaki, Japan.
- 2Department of Neurosurgery, Nagasaki Prefecture Shimabara Hospital, Shimabara, Nagasaki, Japan.
- 3Department of Neurosurgery, Showa Medical University School of Medicine, Tokyo, Japan.
- 4Department of Radiology, Nagasaki University Hospital, Nagasaki, Nagasaki, Japan.
Abstract
Incomplete expansion or distal malapposition of a flow diverter (FD) can lead to unexpected vascular complications. We report a rare case of focal stenosis with adjacent aneurysmal dilatation after FD placement, which was likely related to distal malapposition and altered local hemodynamics, and was treated successfully with the placement of an additional FD. Hemodynamic alterations were evaluated using 4-dimensional flow MRI. A woman in her 60s with no significant medical history underwent MRI for persistent diplopia, which revealed an internal carotid artery aneurysm at the C4 segment. FD placement was performed; however, incomplete distal apposition and suboptimal distal edge expansion were observed at the distal edge of the device. The immediate postoperative course was uneventful. At both the 6-month and 1-year follow-up examinations, MRI and DSA demonstrated focal stenosis distal to the FD with aneurysmal dilatation adjacent to the stenotic segment. A 2nd FD was deployed in a telescoping manner from the C2 segment into the initial FD. Follow-up DSA performed 6 months later showed resolution of the stenosis and aneurysmal dilatation, with complete occlusion of the original aneurysm (O'Kelly-Marotta grade D). Distal malapposition or incomplete expansion of the FD may lead to focal stenosis and secondary aneurysmal dilatation, possibly through altered local hemodynamics and vessel wall injury. Careful attention to distal landing zones and follow-up imaging is essential. Additional FD placement may be an effective treatment option for this rare but clinically important complication.
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BibTeX
@article{nakamura2026delayed,
title = {{Delayed Focal Stenosis and Aneurysmal Dilatation after Flow Diverter Placement Possibly Related to Distal Malapposition.}},
author = {Hikaru Nakamura and Yoichi Morofuji and Kazuaki Okamura and Yuki Matsunaga and Shiro Baba and Kenta Ujifuku and Takeshi Hiu and Koichi Yoshida and Yukishige Hayashi and Minoru Morikawa and Takayuki Matsuo},
journal = {Journal of neuroendovascular therapy},
year = {2026},
month = oct,
doi = {10.5797/jnet.cr.2026-0024},
url = {https://europepmc.org/article/MED/42953612},
note = {CC BY-NC},
}
RIS
TY - JOUR
TI - Delayed Focal Stenosis and Aneurysmal Dilatation after Flow Diverter Placement Possibly Related to Distal Malapposition.
AU - Hikaru Nakamura
AU - Yoichi Morofuji
AU - Kazuaki Okamura
AU - Yuki Matsunaga
AU - Shiro Baba
AU - Kenta Ujifuku
AU - Takeshi Hiu
AU - Koichi Yoshida
AU - Yukishige Hayashi
AU - Minoru Morikawa
AU - Takayuki Matsuo
PY - 2026
DA - 2026/10/24
JO - Journal of neuroendovascular therapy
DO - 10.5797/jnet.cr.2026-0024
UR - https://europepmc.org/article/MED/42953612
AB - Incomplete expansion or distal malapposition of a flow diverter (FD) can lead to unexpected vascular complications. We report a rare case of focal stenosis with adjacent aneurysmal dilatation after FD placement, which was likely related to distal malapposition and altered local hemodynamics, and was treated successfully with the placement of an additional FD. Hemodynamic alterations were evaluated using 4-dimensional flow MRI. A woman in her 60s with no significant medical history underwent MRI for persistent diplopia, which revealed an internal carotid artery aneurysm at the C4 segment. FD placement was performed; however, incomplete distal apposition and suboptimal distal edge expansion were observed at the distal edge of the device. The immediate postoperative course was uneventful. At both the 6-month and 1-year follow-up examinations, MRI and DSA demonstrated focal stenosis distal to the FD with aneurysmal dilatation adjacent to the stenotic segment. A 2nd FD was deployed in a telescoping manner from the C2 segment into the initial FD. Follow-up DSA performed 6 months later showed resolution of the stenosis and aneurysmal dilatation, with complete occlusion of the original aneurysm (O'Kelly-Marotta grade D). Distal malapposition or incomplete expansion of the FD may lead to focal stenosis and secondary aneurysmal dilatation, possibly through altered local hemodynamics and vessel wall injury. Careful attention to distal landing zones and follow-up imaging is essential. Additional FD placement may be an effective treatment option for this rare but clinically important complication.
SN - 1882-4072
SN - 2186-2494
ER -