Quantitative evaluation of the effects of flow diverter treatment on aneurysm hemodynamics using time-resolved rotational angiography.

BACKGROUND: There have been immense advancements in the hardware and software of digital subtraction angiography systems over the last several years. These advancements continue to make progress toward the goals of offering better visualization and reducing radiation exposure. A newer advancement in this arena is presenting three-dimension data over time resulting in four-dimensional-digital subtracted angiography visualization. We have evaluated these protocols related to the evaluation of the treatment of intracranial aneurysms with pipeline flow diversion. METHODS: Four-dimensional-digital subtracted angiography imaging was acquired on an Artis Q Biplane angiographic system (Siemens Healthcare AG, Forchheim, Germany). A six second four-dimensional-digital subtracted angiography protocol was performed pre and post flow diverter placement. Pre and post reconstructed images were sent through a dedicated prototype research workstation (Syngo X-Workplace; Siemens Healthineers AG) for further flow evaluation. RESULTS: The treatment of an aneurysm with flow diversion led to a filling delay of 0.278 ± 0.422 s inside the aneurysms, whereas distal to the aneurysms the filling of the vessel segment occurred earlier post procedural (negative filling delay of -0.15 ± 0.31 s. The flow ratio inside the aneurysm decreased to 63.6 ± 23% of its pre-treatment value and distal to the aneurysm the flow remained substantially the same (flow ratio: 95.6 ± 0.29%). Data showed a relative filling delay of the aneurysm normalized to the distal vessel of 0.43 ± 0.36 s. The relative flow ratio of the aneurysm in comparison to the distal parent vessel was 72.2 ± 31%. CONCLUSIONS: Analysis of a four-dimensional-digital subtracted angiography acquisition allows assessment of the effects of flow diversion treatment on aneurysm hemodynamic parameters and shows a significant decrease in flow inside the aneurysm compared to the parent vessel distal to the aneurysm.

CTA collateral score predicts infarct volume and clinical outcome after endovascular therapy for acute ischemic stroke: a retrospective chart review.

BACKGROUND: Acute ischemic stroke (AIS) due to emergent large-vessel occlusion (ELVO) has a poor prognosis. OBJECTIVE: To examine the hypothesis that a better collateral score on pretreatment CT angiography (CTA) would correlate with a smaller final infarct volume and a more favorable clinical outcome after endovascular therapy (EVT). METHODS: A retrospective chart review of the University of Tennessee AIS database from February 2011 to February 2013 was conducted. All patients with CTA-proven LVO treated with EVT were included. Recanalization after EVT was defined by Thrombolysis in Cerebral Infarction (TICI) score ≥2. Favorable outcome was assessed as a modified Rankin Score ≤3. RESULTS: Fifty patients with ELVO were studied. The mean National Institutes of Health Stroke Scale score was 17 (2-27) and 38 of the patients (76%) received intravenous tissue plasminogen activator. The recanalization rate for EVT was 86.6%. Good clinical outcome was achieved in 32% of patients. Univariate predictors of good outcome included good collateral scores (CS) on presenting CTA (p=0.043) and successful recanalization (p=0.02). Multivariate analysis confirmed both good CS (p=0.024) and successful recanalization (p=0.009) as predictors of favorable outcome. Applying results of the multivariate analysis to our cohort we were able to determine the likelihood of good clinical outcome as well as predictors of smaller final infarct volume after successful recanalization. CONCLUSIONS: Good CS predict smaller infarct volumes and better clinical outcome in patients recanalized with EVT. These data support the use of this technique in selecting patients for EVT. Poor CS should be considered as an exclusion criterion for EVT as patients with poor CS have poor clinical outcomes despite recanalization.

Posterior circulation CT angiography collaterals predict outcome of endovascular acute ischemic stroke therapy for basilar artery occlusion.

INTRODUCTION: The natural history of acute ischemic stroke (AIS) due to basilar artery occlusion (BAO) is poor. Endovascular reperfusion therapy (EVT) improves recanalization rates in patients with emergent large vessel intracranial occlusion. OBJECTIVE: To examine the hypothesis that good collateral patterns identified by pretreatment CT angiography (CTA) might be associated with favorable outcomes after EVT. METHODS: We conducted a retrospective chart review of patients presenting with AIS due to BAO in a tertiary care stroke center during a 4-year period. BAO was diagnosed by CTA in all cases. Admission stroke severity was documented using the National Institute of Health Stroke Scale (NIHSS) score. Pretreatment collateral score for posterior circulation was defined as follows: 0, no posterior communicating artery (PCOM); 1, unilateral PCOM; 2, bilateral PCOM. Favorable outcome was defined as modified Rankin Scale score of 0-2 at 3 months. RESULTS: A total of 21 patients with AIS due to BAO (age range 31-84 years, median admission NIHSS score: 18 points, range 2-38) underwent EVT. Eleven of 21 patients (52.4%) had bilateral PCOMs, while unilateral PCOM was seen in 3 patients (14.3%). Patients with bilateral PCOMs tended (p=0.261) to have less severe stroke at admission than those with absent/unilateral PCOM (median NIHSS score 18 vs 27 points). Neurological improvement during hospitalization (quantified by the median decrease in NIHSS score) and the rate of 3-month functional independence were greater in patients with good collaterals (16 vs 0 points (p=0.016) and 72.7% vs 0% (p=0.001)). CONCLUSIONS: The presence of bilateral PCOMs on pretreatment CTA appears to be associated with more favorable outcomes in BAO treated with EVT.

Comparison of Intraoperative Indocyanine Green Angiography and Digital Subtraction Angiography for Clipping of Intracranial Aneurysms.

BACKGROUND: Residual aneurysm after microsurgical clipping carries a risk of aneurysm growth and rupture. Digital subtraction angiography (DSA) remains the standard to determine the adequacy of clipping. Intraoperative indocyanine green (ICG) angiography is increasingly utilized to confirm optimal clip positioning across the neck and to evaluate the adjacent vasculature. OBJECTIVE: We evaluated the correlation between ICG and DSA in clipped intracranial aneurysms. METHODS: A retrospective study of patients who underwent craniotomy and microsurgical clipping of intracranial aneurysms with ICG for 2 years. Patient characteristics, presentation details, operative reports, and pre- and postclipping angiographic images were reviewed to determine the adequacy of the clipping. RESULTS: Forty-seven patients underwent clipping with ICG and postoperative DSA: 57 aneurysms were clipped; 23 patients (48.9%) presented with subarachnoid hemorrhage. Nine aneurysms demonstrated a residual on DSA not identified on ICG (residual sizes ranged from 0.5 to 4.3 mm; average size: 1.8 mm). Postoperative DSA demonstrated no branch occlusions. CONCLUSION: Intraoperative ICG is useful in the clipping of intracranial aneurysms to ensure a gross patency of branch vessels; however, the presence of residual aneurysms and subtle changes in flow in branch vessels is best seen by DSA. This has important clinical implications with regard to follow-up imaging and surgical/endovascular management.

Initial multicenter technical experience with the Apollo device for minimally invasive intracerebral hematoma evacuation.

BACKGROUND: No conventional surgical intervention has been shown to improve outcomes for patients with spontaneous intracerebral hemorrhage (ICH) compared with medical management. OBJECTIVE: We report the initial multicenter experience with a novel technique for the minimally invasive evacuation of ICH using the Penumbra Apollo system (Penumbra Inc, Alameda, California). METHODS: Institutional databases were queried to perform a retrospective analysis of all patients who underwent ICH evacuation with the Apollo system from May 2014 to September 2014 at 4 centers (Medical University of South Carolina, Stony Brook University, University of California at San Diego, and Semmes-Murphy Clinic). Cases were performed either in the neurointerventional suite, operating room, or in a hybrid operating room/angiography suite. RESULTS: Twenty-nine patients (15 female; mean age, 62 ± 12.6 years) underwent the minimally invasive evacuation of ICH. Six of these parenchymal hemorrhages had an additional intraventricular hemorrhage component. The mean volume of ICH was 45.4 ± 30.8 mL, which decreased to 21.8 ± 23.6 mL after evacuation (mean, 54.1 ± 39.1% reduction; P < .001). Two complications directly attributed to the evacuation attempt were encountered (6.9%). The mortality rate was 13.8% (n = 4). CONCLUSION: Minimally invasive evacuation of ICH and intraventricular hemorrhage can be achieved with the Apollo system. Future work will be required to determine which subset of patients are most likely to benefit from this promising technology.