J Delgado Almandoz

International Retrospective Study of the Pipeline Embolization Device: A Multicenter Aneurysm Treatment Study

BACKGROUND AND PURPOSE: Flow diverters are increasingly used in the endovascular treatment of intracranial aneurysms. Our aim was to determine neurologic complication rates following Pipeline Embolization Device placement for intracranial aneurysm treatment in a real-world setting. MATERIALS AND METHODS: We retrospectively evaluated all patients with intracranial aneurysms treated with the Pipeline Embolization Device between July 2008 and February 2013 in 17 centers worldwide. We defined 4 subgroups: internal carotid artery aneurysms of ≥10 mm, ICA aneurysms of <10 mm, other anterior circulation aneurysms, and posterior circulation aneurysms. Neurologic complications included spontaneous rupture, intracranial hemorrhage, ischemic stroke, permanent cranial neuropathy, and mortality. Comparisons were made with t tests or ANOVAs for continuous variables and the Pearson χ2 or Fisher exact test for categoric variables. RESULTS: In total, 793 patients with 906 aneurysms were included. The neurologic morbidity and mortality rate was 8.4% (67/793), highest in the posterior circulation group (16.4%, 9/55) and lowest in the ICA <10-mm group (4.8%, 14/294) (P = .01). The spontaneous rupture rate was 0.6% (5/793). The intracranial hemorrhage rate was 2.4% (19/793). Ischemic stroke rates were 4.7% (37/793), highest in patients with posterior circulation aneurysms (7.3%, 4/55) and lowest in the ICA <10-mm group (2.7%, 8/294) (P = .16). Neurologic mortality was 3.8% (30/793), highest in the posterior circulation group (10.9%, 6/55) and lowest in the anterior circulation ICA <10-mm group (1.4%, 4/294) (P < .01). CONCLUSIONS: Aneurysm treatment with the Pipeline Embolization Device is associated with the lowest complication rates when used to treat small ICA aneurysms. Procedure-related morbidity and mortality are higher in the treatment of posterior circulation and giant aneurysms.

Diagnostic accuracy and yield of multidetector CT angiography in the evaluation of spontaneous intraparenchymal cerebral hemorrhage.

BACKGROUND AND PURPOSE: Multidetector CT angiography (MDCTA) is emerging as the favored initial diagnostic examination in the evaluation of patients presenting with spontaneous intraparenchymal hemorrhage (IPH). This study aims to evaluate the diagnostic accuracy and yield of MDCTA for the detection of vascular etiologies in adult patients presenting to the emergency department with IPH. MATERIALS AND METHODS: We conducted a retrospective study of 623 consecutive adult patients presenting to the emergency department with IPH, who were evaluated with MDCTA during a 9-year period. CT angiograms were reviewed by 2 neuroradiologists to determine the IPH site and the presence of a vascular etiology. Patients with associated subarachnoid hemorrhage in the basal cisterns were excluded from the study. Medical records were reviewed for risk factors and correlation with final diagnosis. The diagnostic accuracy of MDCTA compared with conventional angiography, intraoperative evaluation, and pathologic findings was determined, when available. Multiple-variable logistic regression analysis was performed to determine clinical and radiologic factors that predict a higher yield of MDCTA. RESULTS: MDCTA demonstrated a vascular etiology in 91 patients (14.6%), with a sensitivity of 96%, specificity of 99%, and diagnostic accuracy of 98%. We found independent, statistically significant higher yields of MDCTA in patients with the following characteristics: 1) age younger than 46 years (47%); 2) lobar (20%) or infratentorial (16%) IPH, especially lobar IPH with associated intraventricular hemorrhage (25%); 3) female sex (18%); or 4) neither known hypertension nor impaired coagulation at presentation (33%). CONCLUSIONS: MDCTA is an accurate diagnostic examination in the evaluation of adult patients presenting with spontaneous IPH and should be performed in all patients with the aforementioned clinical and radiologic characteristics.

Last-Recorded P2Y12 Reaction Units Value Is Strongly Associated with Thromboembolic and Hemorrhagic Complications Occurring Up to 6 Months after Treatment in Patients with Cerebral Aneurysms Treated with the Pipeline Embolization Device

BACKGROUND AND PURPOSE: A recent study identified a preprocedural P2Y12 reaction units value of <60 or >240 as a strong independent predictor of perioperative thromboembolic and hemorrhagic complications after treatment of cerebral aneurysms with the Pipeline Embolization Device. This study aimed to determine whether a last-recorded P2Y12 reaction units value of <60 or >240 predicts thromboembolic and hemorrhagic complications up to 6 months after treatment of cerebral aneurysms with the Pipeline Embolization Device in the same patient cohort. MATERIALS AND METHODS: We recorded patient and aneurysm characteristics, P2Y12 receptor antagonist administered, P2Y12 reaction units value with VerifyNow, procedural variables, and thromboembolic and hemorrhagic complications up to 6 months after Pipeline Embolization Device procedures at our institution during an 8-month period. Complications causing a permanent disabling neurologic deficit or death were considered major. Multivariate regression analysis was performed to identify independent predictors of thromboembolic and hemorrhagic complications. RESULTS: Forty-four patients underwent 48 Pipeline Embolization Device procedures at our institution during the study period. There were 11 thromboembolic and hemorrhagic complications up to 6 months after treatment in our cohort (22.9%), 5 of which were major (10.4%). A last-recorded P2Y12 reaction units value of <60 or >240 was the only independent predictor of all (P = .002) and major (P = .03) thromboembolic and hemorrhagic complications in our cohort. Most patients (71%) required, on average, 2 adjustments to the dose or type of P2Y12 receptor antagonist to remain within the 60–240 target P2Y12 reaction units range. CONCLUSIONS: In our cohort, a last-recorded P2Y12 reaction units value of <60 or >240 was the only independent predictor of all and major thromboembolic and hemorrhagic complications up to 6 months after Pipeline Embolization Device procedures.

Practical Scoring System for the Identification of Patients with Intracerebral Hemorrhage at Highest Risk of Harboring an Underlying Vascular Etiology: The Secondary Intracerebral Hemorrhage Score

BACKGROUND AND PURPOSE: An ICH patients risk of harboring an underlying vascular etiology varies according to baseline clinical and NCCT characteristics. Our aim was to develop a practical scoring system to stratify patients with ICH according to their risk of harboring a vascular etiology. MATERIALS AND METHODS: Using a data base of 623 patients with ICH evaluated with MDCTA during a 9-year period, we developed a scoring system based on baseline clinical characteristics (age group [0–2 points], sex [0–1 point], neither known HTN nor impaired coagulation [0–1 point]), and NCCT categorization (0–2 points) to predict the risk of harboring a vascular lesion as the ICH etiology (SICH score). We subsequently applied the SICH score to a prospective cohort of 222 patients with ICH who presented to our emergency department during a 13-month period. Using ROC analysis, we calculated the AUC and MOP for the SICH score in both the retrospective and prospective patient cohorts separately and the entire patient population. Patients with SAH in the basal cisterns were excluded. RESULTS: A vascular etiology was found in 120 of 845 patients with ICH evaluated with MDCTA (14.2%), most commonly AVMs (45.8%), aneurysms with purely intraparenchymal rupture (21.7%), and DVSTs (16.7%). The MOP was reached at a SICH score of >2, with the highest incidence of vascular ICH etiologies in patients with SICH scores of 3 (18.5%), 4 (39%), 5 (84.2%), and 6 (100%). There was no significant difference in the AUC between both patient cohorts (0.86–0.87). CONCLUSIONS: The SICH score successfully predicts a given ICH patients risk of harboring an underlying vascular etiology and could be used as a guide to select patients with ICH for neurovascular evaluation to exclude the presence of a vascular abnormality.

Diagnostic Yield of Catheter Angiography in Patients with Subarachnoid Hemorrhage and Negative Initial Noninvasive Neurovascular Examinations

These authors explored the diagnostic yield of DSA in patients with SAH and previously negative CTA or MRA. A total of 55 patients who presented with diffuse SAH, perimesencephalic SAH, or sulcal SAH received CTA (n= 47) or MRA (n= 8). Despite normal findings on CTA or MRA, DSA showed vascular lesions in 11% of patients with diffuse SAH and in 1 patient with sulcal SAH. The investigators concluded that DSA is a valuable tool in patients with diffuse or sulcal SAH in whom previous noninvasive examinations are negative. BACKGROUND AND PURPOSE: The yield of DSA in patients with SAH and negative initial noninvasive neurovascular examinations (CTA or MRA) is not well-understood. This study aimed to determine the yield of DSA for the detection of causative vascular lesions in this clinical scenario. MATERIALS AND METHODS: We examined the yield of DSA for the detection of causative vascular lesions in a cohort of patients presenting to our institution with SAH and negative initial noninvasive neurovascular examinations during a 5-year period. Two experienced neuroradiologists independently evaluated the NCCT to determine the SAH pattern (diffuse, perimesencephalic, or peripheral sulcal) and the catheter angiograms to assess the presence of a causative vascular lesion. RESULTS: Fifty-five patients were included in the study, with a mean age of 58.2 years (median, 58 years; range, 25–88 years). Twenty-eight patients were men (50.9%), and 27 were women (49.1%). The initial noninvasive examination was a CTA in 47 patients (85.5%) and an MRA in 8 patients (14.5%). Thirty-three patients had diffuse SAH (60%); 11, perimesencephalic SAH (20%); and 11, peripheral sulcal SAH (20%). DSA demonstrated a causative vascular lesion in 6 patients (10.9%), 5 of whom had diffuse SAH (yield of 15.2%) and 1 of whom had peripheral sulcal SAH (yield of 9.1%). No causative vascular lesions were found in patients with perimesencephalic SAH. CONCLUSIONS: DSA is a valuable tool in the evaluation of patients with diffuse and peripheral sulcal SAH who have negative initial noninvasive neurovascular examinations, demonstrating a causative vascular lesion in 15.2% and 9.1% of patients, respectively.

Susceptibility-Weighted Imaging: A New Tool in the Diagnosis and Evaluation of Abnormalities of the Vein of Galen in Children

SUMMARY We retrospectively identified 9 consecutive children, 3 males and 6 females (age 5.2 ± 6.3 years, range 1 day to 18 years), with known or suspected AVGs who underwent MR imaging, including SWI, at our institution between January 2007 and March 2011. On the SWI sequence, arterialized blood flow was considered to be present in the vein of Galen or its tributaries when these showed abnormal signal hyperintensity from arteriovenous shunting. SWI findings were correlated with findings from DSA studies or findings from time-of-flight or contrast-enhanced MR angiography sequences. SWI was found to accurately differentiate between high-flow and low-flow AVGs and was also useful in characterizing the arterial supply and venous drainage patterns associated with high-flow AVGs.

Contrast Extravasation on CT Angiography Predicts Hematoma Expansion and Mortality in Acute Traumatic Subdural Hemorrhage

Here the authors used the “spot sign” to evaluate contrast extravasation in subdural hematomas. A cohort of 157 patients underwent emergent CTA and 48-hour follow-up CT. Of these subjects, 15% showed active contrast extravasation initially and interobserver agreement for its detection was excellent. The presence of active extravasation correlated with significant hematoma expansion and predicted higher in-hospital mortality. Thus, this sign identifies high-risk patients. BACKGROUND AND PURPOSE: The presence of active contrast extravasation at CTA predicts hematoma expansion and in-hospital mortality in patients with nontraumatic intracerebral hemorrhage. This study aims to determine the frequency and predictive value of the contrast extravasation in patients with aSDH. MATERIALS AND METHODS: We retrospectively reviewed 157 consecutive patients who presented to our emergency department over a 9-year period with aSDH and underwent CTA at admission and a follow-up NCCT within 48 hours. Two experienced readers, blinded to clinical data, reviewed the CTAs to assess for the presence of contrast extravasation. Medical records were reviewed for baseline clinical characteristics and in-hospital mortality. aSDH maximum width in the axial plane was measured on both baseline and follow-up NCCTs, with hematoma expansion defined as >20% increase from baseline. RESULTS: Active contrast extravasation was identified in 30 of 199 discrete aSDHs (15.1%), with excellent interobserver agreement (κ = 0.80; 95% CI, 0.7–0.9). The presence of contrast extravasation indicated a significantly increased risk of hematoma expansion (odds ratio, 4.5; 95% CI, 2.0–10.1; P = .0001) and in-hospital mortality (odds ratio, 7.6; 95% CI, 2.6–22.3; P = 0.0004). In a multivariate analysis controlled for standard risk factors, the presence of contrast extravasation was an independent predictor of aSDH expansion (P = .001) and in-hospital mortality (P = .0003). CONCLUSIONS: Contrast extravasation stratifies patients with aSDH into those at high risk and those at low risk of hematoma expansion and in-hospital mortality. This distinction could affect patient treatment, clinical trial selection, and possible surgical intervention.

Frequency of Adequate Contrast Opacification of the Major Intracranial Venous Structures with CT Angiography in the Setting of Intracerebral Hemorrhage: Comparison of 16- and 64-Section CT Angiography Techniques

BACKGROUND AND PURPOSE: DVST is an important cause of ICH because its treatment may require anticoagulation or mechanical thrombectomy. We aimed to determine the frequency of adequate contrast opacification of the major intracranial venous structures in CTAs performed for ICH evaluation, which is an essential factor in excluding DVST as the ICH etiology. MATERIALS AND METHODS: Two readers retrospectively reviewed CTAs performed in 170 consecutive patients with ICH who presented to our emergency department during a 1-year period to determine by consensus whether qualitatively, contrast opacification in each of the major intracranial venous structures was adequate to exclude DVST. “Adequate contrast opacification” was defined as homogeneous opacification of the venous structure examined. “Inadequate contrast opacification” was defined as either inhomogeneous opacification or nonopacification of the venous structure examined. Delayed scans, if obtained, were reviewed by the same readers blinded to the first-pass CTAs to determine the adequacy of contrast opacification in the venous structures according to the same criteria. In patients who did not have an arterial ICH etiology, the same readers determined if thrombosis of an inadequately opacified intracranial venous structure could have potentially explained the ICH by correlating the presumed venous drainage path of the ICH with the presence of inadequate contrast opacification within the venous structure draining the venous territory of the ICH. CTAs were performed in 16- or 64-section CT scanners with bolus-tracking, scanning from C1 to the vertex. Patients with a final diagnosis of DVST were excluded. We used the Pearson χ2 test to determine the significance of the differences in the frequency of adequate contrast opacification within each of the major intracranial venous structures in scans obtained using either a 16- or 64-section MDCTA technique. RESULTS: Fifty-eight patients were evaluated with a 16-section MDCTA technique (34.1%) and 112 with a 64-section technique (65.9%). Adequate contrast opacification within all major noncavernous intracranial venous structures was significantly less frequent in first-pass CTAs performed with a 64-section technique (33%) than in those performed with a 16-section technique (60%, P value < .0001). Delayed scans were obtained in 50 patients, all of which demonstrated adequate contrast opacification in the major noncavernous intracranial venous structures. In 142 patients with supratentorial or cerebellar ICH without an underlying arterial etiology, we found that thrombosis of an inadequately opacified major intracranial venous structure could have potentially explained the ICH in 38 patients (26.8%), most examined with a 64-section technique (86.8%). CONCLUSIONS: Inadequate contrast opacification of the major intracranial venous structures is common in first-pass CTAs performed for ICH evaluation, particularly if performed with a 64-section technique. Acquiring delayed scans appears necessary to confidently exclude DVST when there is strong clinical or radiologic suspicion.

E-057 Process Improvement in Door-to-Groin Puncture Times at a Comprehensive Stroke Center Shows a Trend Towards Reduced Mortality at 90 Days

Introduction Safe and effective endovascular treatment of acute ischemic stroke is dependent on prompt intervention. In light of the positive trials published last year, we intensified our efforts to improve the process of taking patients from the emergency department to the angiography suite for mechanical thrombectomy. Methods At the beginning of 2015, a process improvement project to improve door-to-groin puncture times for mechanical thrombectomy for emergent large vessel occlusions was undertaken at our institution. After a systematic analysis of the process, the following key changes were standardized: early consultation with the neurointerventionalist for patients presenting with a high National Institutes of Health Stroke Scale (NIHSS ≥6), the stroke neurologist and the neurointerventionalist meet the patient in the emergency department for transfers or meet in the CT department for non-transfers, elimination of emergency physician triage for medically stable patients, elimination of lab tests such as creatinine, establishment of a minimum level of clinical information required for the sedation nurse to care for stroke patients safely, institution of a “stroke bag” containing all necessary devices to perform efficient thrombectomy, standardized setup of the procedure table and devices for all operators, calling for patients when the sedation nurse is ready without waiting for the entire team, elimination of unnecessary preoperative steps (e.g. Foley catheter placement, groin shaving, checking of distal pulses), and institution of an abbreviated time-out procedure. All attempted thrombectomies performed in 2013 and 2014 were compared to those performed in 2015 visà-vis the following variables: door-to-groin puncture time, symptomatic intracranial hemorrhage (SICH) rate as defined by SITS-MOST criteria, 90 day mortality rate, and 90 day rate of good clinical outcome defined by a modified Rankin Scale (mRS) of 0–2. A one-tailed Student’s t-test and Fisher’s exact tests were performed. A p-value <0.05 was considered statistically significant. Results From January 2013 to December 2015, we attempted 108 mechanical thrombectomies. Of these, 43 were in 2015 (40%). Both the mean and median door-to-groin puncture times were significantly reduced from the previous two years (35 minutes versus 89 minutes and 22 minutes versus 73 minutes, respectively, p < 0.001). There was a trend towards reduced mortality at 90 days (16% versus 26%, p = 0.166). The rates of SICH and mRS 0–2 at 90 days were not significantly different (see Table 1).Abstract E-057 Table 1 2013 and 2014 2015 p-value Thrombectomies 65 43 Door-to-groin punctureMean time (minutes)Median time (minutes) 8973 3522 <0.001 SICH 3 (5%) 3 (7%) 0.452 90 day mortality 17 (26%) 7 (16%) 0.166 90 day mRS 0–2 24 (37%) 18 (42%) 0.376 Conclusion Our systematic process improvement initiative significantly reduced door-to-groin puncture times and showed a trend towards reduced mortality at 90 days. A multidisciplinary approach and ensuring hospital system investment are key to an effective process. Disclosures Y. Kayan: 2; C; Medtronic, Penumbra. J. Delgado Almandoz: 2; C; Medtronic, Penumbra. M. Young: None. J. Fease: None. J. Scholz: None. A. Milner: None. T. Hehr: None. M. Mulder: None. P. Roohani: None. R. Tarrel: None.

O-005 Frequency of Post-Procedural Diffusion Weighted Imaging Abnormalities and Association with Delayed Ipsilateral Intracerebral Haemorrhages in Patients Undergoing Endovascular Treatment of Cerebral Aneurysms with the Pipeline Embolization Device

Purpose To determine the frequency and predictors of post-procedural diffusion-weighted-imaging (DWI) abnormalities in patients with cerebral aneurysms treated with the Pipeline Embolization Device (PED). Methods Two interventional neuroradiologists reviewed post-procedural MRI examinations performed in patients with cerebral aneurysms treated with the PED at our institution to determine the number of DWI abnormalities present in the vascular territory of the treated aneurysm. Baseline patient and aneurysm characteristics and procedural variables were recorded. Results Twenty-two patients were included, 15 female (68%) and 7 male (32%), mean age 53.2 years (25–79 years). Mean aneurysm size 11.2 mm (2.5–22 mm), mean neck size 6.5 mm (1.6–17 mm), 5 aneurysms were fusiform (22.7%). Mean pre-procedure P2Y12 reaction units (PRU) value was 164.9 (81–275). PEDs were deployed in the internal carotid artery (ICA) in 16 patients (72.8%), middle cerebral artery in 3 patients (13.6%) and vertebral artery in 3 patients (13.6%). Mean procedure time was 86 min (median 75 min, range 39–189 min). Mean number of PEDs deployed was 1.2. At the time of post-procedural MRI, 4 patients exhibited focal neurological deficits (18%, mean 3.5 days post-procedure) and 18 were asymptomatic (82%, all on post-operative day [POD] 1). At least 1 DWI abnormality was observed in 17 patients (77%), including all 4 symptomatic (100%) and 13 asymptomatic patients (72%). Mean number of DWI abnormalities was 12.5 (median 4, range 0–70), with a trend towards a higher number in symptomatic patients (mean 26.8, range 5–70) than in asymptomatic patients (mean 9.3, range 0–48, p-value 0.1). Eleven patients had a high DWI burden, defined as ≥5 DWI abnormalities (50%). Predictors of a high DWI burden were fusiform aneurysm morphology (100%, p-value 0.035), female sex (67%, p-value 0.06), and procedure time >90 min (70%, p-value 0.09). Conclusion We observed a high rate of asymptomatic ipsilateral DWI abnormalities after PED procedures (72%). The combination of a high DWI burden and P2Y12-receptor over-inhibition post-procedure may play an important role in the aetiology of delayed ipsilateral ICHs encountered after PED procedures. Abstract O-005 Figure 1 Female patient undergoing urgent treatment of fusiform right ICA aneurysm on ticagrelor, procedure time 93 min, with high asymptomatic DWI burden (n = 48) and an asymptomatic ipsilateral intracerebral haemorrhage (ICH) identified in routine MRI on POD 1 (PRU 49 at time of asymptomatic ICH). On POD 4, after administration of 75 mg clopidogrel doses on POD 2 and 3, the patient developed severe headache, hemiparesis and hemianopsia with marked ICH enlargement and further P2Y12-receptor over-inhibition (PRU 8) Disclosures J. Delgado Almandoz: 2; C; Covidien/ev3. Y. Kadkhodayan: 2; C; Covidien/ev3. J. Fease: None. J. Scholz: None. A. Blem: None. K. Tran: None. B. Crandall: 2; C; Covidien/ev3.