Flow diversion for internal carotid artery aneurysms with compressive neuro-ophthalmologic symptoms: clinical and anatomical results in an international multicenter study.

BACKGROUND: Scientific data on the safety and efficacy of flow diverter stents (FDS) for the treatment of unruptured internal carotid artery (ICA) aneurysms with compressive neuro-ophthalmological symptoms are scarce. We studied this subject in a retrospective international multicenter series, pooling data of 9 tertiary care neurointerventional departments. OBJECTIVE: To investigate, in a retrospective, multicentric cohort of patients presenting with visual or oculomotor symptoms attributed to a compressive carotid artery in an unruptured intracranial aneurysm, the safety and efficacy profiles of FDS, by analyzing neuro-opthalmologic symptom evolution following FDS placement, complications, and aneurysm obliteration rates. METHODS: All patients treated since 2015 with a FDS for an unruptured aneurysm of the ICA with signs of compressive cranial nerve symptoms (CN II, III, IV, VI) were included. RESULTS: We treated 55 patients with 55 aneurysms; 21 (38.2%) patients had oculomotor and 15 (27.3%) visual symptoms only; 19 (34.5%) presented with a combination of both. Treatment-related morbidity/mortality occurred in 7.2% and 3.6%, respectively. At last imaging follow-up (13.1±10.5 months) rates of complete aneurysm occlusion, neck remnant, and aneurysm remnant were 72%, 14%, and 14%, respectively. At last clinical follow-up after 13±10.5 months, 19/51 (37.3%) patients had recovered completely and 18/51 (35.3%) had recovered at least partially from their neuro-ophthalmological symptoms. In multivariable models, a longer delay between symptom onset and treatment was associated with higher odds for incomplete recovery and lower odds for any improvement (aOR 1.03 (95% CI 1.01 to 1.07), p=0.047 and 0.04 (0-0.81), p=0.020). Incomplete recovery was independently associated with older age and fusiform aneurysms. CONCLUSION: FDS are effective to treat patients with compressive aneurysms of the ICA causing neuro-ophthalmological symptoms, especially when treatment is initiated early after symptom onset, and aneurysm occlusion is adequate. However, serious complications are not rare.

Suction force rather than aspiration flow correlates with recanalization in hard clots: an in vitro study model.

BACKGROUND: ANA Advanced Neurovascular Access provides a novel funnel component designed to reduce clot fragmentation and facilitate retrieval in combination with stent-retrievers (SRs) in stroke patients by restricting flow and limiting clot shaving. In previous publications ANA presented excellent in vitro/in vivo efficacy data, especially with fibrin-rich hard clots. We aimed to determine the main physical property responsible for these results, namely suction force versus aspiration flow. METHODS: We evaluated in a bench model the suction force and flow generated by ANA and compared them to other neurovascular catheters combined with a SR (Solitaire). Aspiration flow was evaluated with a flow rate sensor while applying vacuum pressure with a pump. Suction force was determined using a tensile strength testing machine and a purposely designed tool that completely seals the device tip simulating complete occlusion by a hard clot. Suction force was defined as the force needed to separate the device from the clot under aspiration. All experiments were repeated five times, and mean values used for comparisons. RESULTS: Aspiration flow increased with the inner diameter of the device: ANA 1.85±0.04 mL/s, ACE68 3.74±0.05 mL/s, and 8F-Flowgate2 5.96±0.30 mL/s (P<0.001). After introducing the SR, the flow was reduced by an average of 0.57±0.12 mL/s. Due to its larger distal surface, ANA suction force (1.69±0.40 N) was significantly higher than ACE68 (0.26±0.04 N) and 8F-Flowgate2 (0.42±0.06 N) (P<0.001). After introducing the SR, suction force variation was not relevant except for ANA that increased to 2.64±0.41 N. CONCLUSION: Despite lower in vitro aspiration flow, the ANA design showed a substantially higher suction force than other thrombectomy devices.