Introduction: Flow diversion of ICA termination (ICAT) aneurysms is an option when surgical or other endovascular techniques are inadequate. Jailing the ACA with a flow diverter is effective when the Acom is patent. Jailing the MCA, a truly terminal circulation, is sometimes necessary and has not been reported.
Methods: A prospective, IRB-approved database was analyzed for patients with PED placement from the ACA to the ICA during cerebral aneurysm treatment.
Results: Nine cases were identified, including 5 proximal A1, 3 Pcom, and 1 ICAT aneurysm locations. Average aneurysm size was 8.3mm (range 3-17), with 67% saccular and 78% right-sided. Primary indication for treatment was significant dome irregularity (44%), recurrence or enlargement (33%), underlying collagen vascular disorder (11%), and traumatic pseudoaneurysm (11%). Preservation of the ipsilateral ACA (with PED placed in A1) was performed when the Acom (67%) or contralateral A1 (33%) were absent on angiography. Adjunctive coiling was done in 4 cases (44%). One major stroke occurred. This patient had an irregular 8mm proximal left A1 aneurysm treated with PED and coiling. Post-treatment angiography showed slight left MCA delay, however, hypotension during management of a retroperitoneal hematoma requiring surgical repair led to left MCA stroke ultimately resulting in death. Follow-up DSA in all other patients (average interval 15mos) showed complete aneurysm obliteration (100%). The jailed MCA showed minimal or mild delay (primarily anterograde flow) in 75% of cases and significant delay (reliance primarily on ACA and ECA collaterals) in 25%. One patient experienced mild weakness from MCA watershed territory ischemia during vasovagal hypotension after treatment and is currently mRS=2 at 18 months follow-up.
Conclusions: Rare circumstances necessitate jailing the MCA with a flow diverting stent. With strict attention to perfusion pressures during a period of collateral recruitment, excellent occlusion outcomes can be achieved while minimizing ischemic risks.
Patient Care: This study will improve current knowledge of the clinical ramifications of jailing the MCA with a flow diverting device for the treatment of ICA aneurysms.
Learning Objectives: By the conclusion of this session, participants should be able to:
1) Describe the circumstances warranting consideration of jailing the MCA with a flow diverting stent;
2) Discuss, in small groups, the occlusion outcomes and risks associated with jailing the MCA as presented in this case series.