Predictors Of Incomplete Occlusion Research Articles

Off-Label use of Woven EndoBridge device for intracranial brain aneurysm treatment: Modeling of occlusion outcome

IntroductionThe Woven EndoBridge (WEB) device is emerging as a novel therapy for intracranial aneurysms, but its use for off-label indications requires further study. Using machine learning, we aimed to develop predictive models for complete occlusion after off-label WEB treatment and to identify factors associated with occlusion outcomes. MethodsThis multicenter, retrospective study included 162 patients who underwent off-label WEB treatment for intracranial aneurysms. Baseline, morphological, and procedural variables were utilized to develop machine-learning models predicting complete occlusion. Model interpretation was performed to determine significant predictors. Ordinal regression was also performed with occlusion status as an ordinal outcome from better (Raymond Roy Occlusion Classification [RROC] grade 1) to worse (RROC grade 3) status. Odds ratios (OR) with 95 % confidence intervals (CI) were reported. ResultsThe best performing model achieved an AUROC of 0.8 for predicting complete occlusion. Larger neck diameter and daughter sac were significant independent predictors of incomplete occlusion. On multivariable ordinal regression, higher RROC grades (OR 1.86, 95 % CI 1.25-2.82), larger neck diameter (OR 1.69, 95 % CI 1.09-2.65), and presence of daughter sacs (OR 2.26, 95 % CI 0.99-5.15) were associated with worse aneurysm occlusion after WEB treatment, independent of other factors. ConclusionThis study found that larger neck diameter and daughter sacs were associated with worse occlusion after WEB therapy for aneurysms. The machine learning approach identified anatomical factors related to occlusion outcomes that may help guide patient selection and monitoring with this technology. Further validation is needed.

Predictors of occlusion, long-term outcomes, and safety in a cohort of 674 aneurysms treated with the Pipeline embolization device.

By providing a more physiological approach to the treatment of intracranial aneurysms, the Pipeline embolization device (PED) has revolutionized the endovascular treatment of aneurysms. Although there are many flow diverters on the market, the authors report their experience with the PED, the first flow diverter to be approved by the Food and Drug Administration. They aimed to assess the efficacy and safety of PED flow diversion for the treatment of a wide range of aneurysms, as well as to look at factors affecting occlusion. This is a retrospective study of a prospectively maintained database of patients treated with the PED between January 2011 and December 2019. Charts were reviewed for patient, aneurysm, and procedure characteristics. The primary outcomes of interest were complication rates, occlusion outcomes (O'Kelly-Marotta grading scale), and functional outcomes (modified Rankin Scale [mRS]). Secondary outcomes included predictors of incomplete occlusion at 6 and 24 months of follow-up. The study cohort included 581 patients with 674 aneurysms. Most aneurysms (90.5%) were in the anterior circulation and had a saccular morphology (85.6%). Additionally, 638 aneurysms (94.7%) were unruptured, whereas 36 (5.3%) were acutely ruptured. The largest mean aneurysm diameter was 8.3 ± 6.1 mm. Complications occurred at a rate of 5.5% (n = 32). The complete occlusion rate was 89.3% at 24 months' follow-up, and 94.8% of patients had a favorable neurological outcome (mRS score 0-2) at the last follow-up. On multivariate analysis, predictors of incomplete aneurysm occlusion at 6 months were hypertension (OR 1.7, p = 0.03), previous aneurysm treatment (OR 2.4, p = 0.001), and increasing aneurysm neck diameter (OR 1.2, p = 0.02), whereas a saccular morphology was protective (OR 0.5, p = 0.05). Predictors of incomplete occlusion at 24 months were increasing aneurysm neck diameter (OR 1.2, p = 0.01) and previous aneurysm treatment (OR 2.3, p = 0.01). The study findings are corroborated by those of previous studies and trials. The complete occlusion rate was 89.3% at 24 months' follow-up, with 94.8% of patients having favorable functional outcomes (mRS score 0-2). Aneurysm treatment before PED deployment and an increasing aneurysm neck diameter increase the risk of incomplete occlusion at 6 and 24 months.

Inflow Angle and Height-Width Ratio are Predictors of Incomplete Occlusion at One and Two Years After Flow Diverter Treatment for Small- and Medium-Sized Internal Carotid Artery Aneurysms

We investigated the association between the inflow angle of aneurysms and their occlusion status at 1 and 2years after flow diverter (FD) treatment. We retrospectively analyzed 42 consecutive patients from a single center with 43 untreated, unruptured internal carotid artery (ICA) proximal to communicating segment, saccular aneurysms sized <12mm. At 1year posttreatment, the complete occlusion (CO) rate was 58.1%. On univariate analyses, the proportion of inflow angle >90° was significantly lower in the CO group than in the incomplete occlusion group (20.0% VS. 83.3%; P < 0.001). The CO incidence decreased with a height-width (H/W) ratio of <1.2 (P= 0.059). On multivariate analysis, an H/W ratio of <1.2 (odds ratio [OR], 0.076; P= 0.027) and an inflow angle of >90° (OR, 0.020; P= 0.0011) significantly influenced CO at 1year post FD. At 2years posttreatment, the CO rate was 76.3% (29/38 cases with available follow-up data). On univariate analyses, in the CO group compared to the incomplete occlusion group, the proportion of H/W ratio <1.2 was significantly lower (P= 0.005) and the proportion of inflow angle >90° was significantly lower (P= 0.021); aneurysm dome size tended to be larger (8.5mm vs. 7.1mm; P= 0.080). On multivariate analysis, an H/W ratio <1.2 (OR, 0.042; P= 0.015) and an inflow angle >90° (OR: 0.088; P= 0.031) significantly influenced CO at 2years post FD. The inflow angle of >90° and H/W ratio <1.2 may significantly influence the CO rate in small- or medium-sized internal carotid artery aneurysms 1 and 2 years post FD.

166 Predictors of Incomplete Aneurysm Occlusion After Treatment with Pipeline Embolization Device: PREMIER Trial 1-year Analysis

INTRODUCTION: Failure of treatment with Pipeline Embolization Device (PED) occurs in 16.1% to 24.6% of aneurysms. Studies investigating mechanisms behind PED failure are mostly retrospective series with conflicting findings. We performed an analysis of aneurysms that failed to achieve complete occlusion in the Prospective Study on Embolization of Intracranial Aneurysms with the Pipeline Device (PREMIER) trial. METHODS: PREMIER was a prospective, multicenter and single-arm interventional. Assessment images was done by independent core laboratory. We retrospectively analyzed patients who failed the primary efficacy endpoint. Aneurysms with incomplete occlusion (RR &gt; 1) were further analyzed and compared to completely occluded aneurysms. RESULTS: Twenty-five (18.1%) aneurysms were incompletely occluded at 1-year. Twenty-two patients had RR-3 and 3 had RR-2. There was a median reduction of 0.9 mm (IQR 0.41-2.43) in maximum-diameter between pre-procedure and 1-year follow-up. Mean age of patients with incomplete occlusion was significantly higher than in those with complete occlusion (mean ±SD; 59.9 ± 10.4 vs 53.6 ± 11.2, P = 0.011). Smoking (P = 0.045) and C6 segment location (P = 0.005) were significantly associated with complete occlusion, while location at V4 (P = 0.01) and C7 (P = 0.007) segments and involvement of a side branch (&lt;0.001) were significantly associated with incomplete occlusion. There was no difference in the rate of inadequate wall apposition between complete and incomplete occlusion groups (12% vs 12.4%, P = 1). In multivariable logistic regression, significant predictors of incomplete occlusion were non-smoker status (adjusted OR, 4.49; 95% CI, 1.11-18.09; p = 0.03), and side branch involvement (adjusted OR, 11.68; 95% CI, 3.84-35.50; P &lt; 0.0001), while the C6 location had reduced odds of incomplete occlusion versus those at other segment locations (adjusted OR, 0.29; 95% CI, 0.10-0.84; p = 0.02). CONCLUSION: In the PREMIER cohort, non-smoking status and vessel branch involvement were the strongest predictors of incomplete occlusion at 1-year. Although the presence of side branches can lead to incomplete occlusion, we observed decrease in aneurysm size and stable remodeling. The efficacy of protecting against rupture remains to be confirmed in longer follow-up. The results from our prospective study is consistent with previous retrospective series and warrants considerations for technique adaptations to achieve higher occlusion rates.

475 Is left atrial appendage device compression rate a predictor of incomplete occlusion in patients undergoing watchman device implantation?

Abstract Aims Transesophageal echocardiography (TEE) is a standard peri-procedural imaging modality in patients undergoing percutaneous left atrial appendage (LAA) occlusion. An accurate device sizing is pivotal to assess stability and achieve successful closure. In this prospective study, we sought to evaluate the correlation between Watchman device compression rates (DCRs) and risk of incomplete LAA occlusion at follow-up in patients undergoing Watchman device implantation. Methods and results Two-dimensional TEE via a commercially available transducer (Vivid, Philips) was performed during the procedure and within 3 months after the procedure. LAA size, morphology, and DCRs [(original device size—size after deployment)/original device size; %] were assessed in a mid-oesophageal view at 0°, 45°, 90° and 135°, according to company recommendations. Residual leaks ≥ 3 mm were classified as significant. Between 2016 and 2018, 116 patients underwent LAA occlusion with a Watchman device at our institution. The mean age was 74 ± 9 years and 60.4% (n = 70) were males. The average CHA2DS2-VASc and HAS-BLED scores were 4.7 ± 1.7 and 2.5 ± 1.1, respectively. The final device size was 21 mm in 11 (9.5%) patients, 24 mm in 28 (24.1), 27 mm in 27 (23.3%), 30 mm in 26 (22.4%), and 33 mm in 24 (20.7). At follow-up TEE, 16 (13.8%) patients were found to have a significant (≥3 mm) residual leak. The average DCRs measured at different angles in patients with and without leak were not significantly different (24 ± 8% vs. 26 ± 7% at 0°, P = 0.47; 23 ± 9% vs. 25 ± 7% at 45°, P = 0.58; 23 ± 8% vs. 23 ± 6% at 90°, P = 0.61; 22 ± 8% vs. 21 ± 7% at 135°, P = 0.61). At receiver operating characteristic (ROC) analysis, the areas under the curve to discriminate between patients with/without leak were 0.58, 0.57, 0.55, and 0.46 for DCRs measured at 0°, 45°, 90°, and 135° angles. Conclusions Peri-procedural assessment of DCRs does not appear to be an accurate method to predict LAA complete occlusion in patients undergoing Watchman device implantation.

Predictors of incomplete aneurysm occlusion after treatment with the Pipeline Embolization Device: PREMIER trial 1 year analysis

BackgroundFlow diverters have revolutionized the treatment of intracranial aneurysms. Nevertheless, some aneurysms fail to occlude with flow diversion. The Prospective Study on Embolization of Intracranial Aneurysms with the Pipeline Device...

Repeat Flow Diversion for Cerebral Aneurysms Failing Prior Flow Diversion: Safety and Feasibility From Multicenter Experience.

Aneurysmal persistence after flow diversion (FD) occurs in 5% to 25% of aneurysms, which may necessitate retreatment. There are limited data on safety/efficacy of repeat FD-a frequently utilized strategy in such cases. A series of consecutive patients undergoing FD retreatment from 15 centers were reviewed (2011-2019), with inclusion criteria of repeat FD for the same aneurysm at least 6 months after initial treatment, with minimum of 6 months post-retreatment imaging. The primary outcome was aneurysmal occlusion, and secondary outcome was safety. A multivariable logistic regression model was constructed to identify predictors of incomplete occlusion (90%-99% and <90% occlusion) versus complete occlusion (100%) after retreatment. Ninety-five patients (median age, 57 years; 81% women) harboring 95 aneurysms underwent 198 treatment procedures. Majority of aneurysms were unruptured (87.4%), saccular (74.7%), and located in the internal carotid artery (79%; median size, 9 mm). Median elapsed time between the first and second treatment was 12.2 months. Last available follow-up was at median 12.8 months after retreatment, and median 30.6 months after the initial treatment, showing complete occlusion in 46.2% and near-complete occlusion (90%-99%) in 20.4% of aneurysms. There was no difference in ischemic complications following initial treatment and retreatment (4.2% versus 4.2%; P>0.99). On multivariable regression, fusiform morphology had higher nonocclusion odds after retreatment (odds ratio [OR], 7.2 [95% CI, 1.97-20.8]). Family history of aneurysms was associated with lower odds of nonocclusion (OR, 0.18 [95% CI, 0.04-0.78]). Likewise, positive smoking history was associated with lower odds of nonocclusion (OR, 0.29 [95% CI, 0.1-0.86]). History of hypertension trended toward incomplete occlusion (OR, 3.10 [95% CI, 0.98-6.3]), similar to incorporated branch into aneurysms (OR, 2.78 [95% CI, 0.98-6.8]). Repeat FD for persistent aneurysms carries a reasonable success/safety profile. Satisfactory occlusion (100% and 90%-99% occlusion) was encountered in two-thirds of patients, with similar complications between the initial and subsequent retreatments. Fusiform morphology was the strongest predictor of retreatment failure.

Neck Location on the Outer Convexity is a Predictor of Incomplete Occlusion in Treatment with the Pipeline Embolization Device: Clinical and Angiographic Outcomes

With the increasing use of the Pipeline Embolization Device for the treatment of aneurysms, predictors of clinical and angiographic outcomes are needed. This study aimed to identify predictors of incomplete occlusion at last angiographic follow-up.In our retrospective, single-center cohort study, 105 ICA aneurysms in 89 subjects were treated with Pipeline Embolization Devices. Patients were followed per standardized protocol. Clinical and angiographic outcomes were analyzed. We introduced a new morphologic classification based on the included angle of the parent artery against the neck location: outer convexity type (included angle, <160°), inner convexity type (included angle, >200°), and lateral wall type (160° ≤ included angle ≤200°). This classification reflects the metal coverage rate and flow dynamics.Imaging data were acquired in 95.3% of aneurysms persistent at 6 months. Complete occlusion was achieved in 70.5%, and incomplete occlusion, in 29.5% at last follow-up. Multivariable regression analysis revealed that 60 years of age or older (OR, 5.70; P = .001), aneurysms with the branching artery from the dome (OR, 10.56; P = .002), fusiform aneurysms (OR, 10.2; P = .009), and outer convexity-type saccular aneurysms (versus inner convexity type: OR, 30.3; P < .001; versus lateral wall type: OR, 9.71; P = .001) were independently associated with a higher rate of incomplete occlusion at the last follow-up. No permanent neurologic deficits or rupture were observed in the follow-up period.The aneurysm neck located on the outer convexity is a new, incomplete occlusion predictor, joining older age, fusiform aneurysms, and aneurysms with the branching artery from the dome. No permanent neurologic deficits or rupture was observed in the follow-up, even with incomplete occlusion.

Procedural Complications and Factors Influencing Immediate Angiographic Results after Endovascular Treatment of Small (

Background and objective: There are technical challenges to complete occlusion of small (<5 mm) ruptured intracranial aneurysms (SRAs) using endovascular treatment (EVT). This study analyzed factors influencing immediate angiographic results in SRAs after EVT. Material and Methods: Intraoperative angiograms and medical records of 290 patients, who underwent EVT for SRAs at 2 stroke centers in China between January 2009 and October 2016, were retrospectively reviewed and evaluated. Results: Immediate complete occlusion was achieved in 213 (73.4%) aneurysms. Aneurysms with a smaller aspect ratio, those less than 3 mm in size, irregular shape, small basal outpouching, multiple aneurysms, poorer Hunt and Hess grade, and location of communication arteries demonstrated higher rates of incomplete occlusion, although the differences were not statistically significant. Multivariate logistic regression analysis revealed that SRAs with parent artery stenosis greater than or equal to 50% and lobulation demonstrated a higher incidence of incomplete occlusion. Intra-procedural rupture occurred in 13 (6.1%) patients in the complete occlusion group, and 3 (3.9%) in the incomplete occlusion group (P = .467). Thromboembolic complications occurred in 3 (1.0%) patients, and 4 (1.9%) underwent decompressive craniotomy after EVT, all of whom were in the complete occlusion group. Nine (4.2%) patients in the complete occlusion group and 2 (2.6%) in the incomplete occlusion group (P = .733) experienced intraprocedural vasospasm, with corresponding morbidity and mortality rates of 15.0% and 2.1%, respectively. Conclusions: Proximal parent artery stenosis greater than or equal to 50% and lobulation were independent predictors of incomplete occlusion in patients with SRAs. Higher rates of intraprocedural rupture, thromboembolic complications, intraprocedural vasospasm, and mortality were found in the complete occlusion group; however, these differences were not statistically significant. Complete occlusion of SRAs may be achieved without additional mortality and perioperative complications.

Procedure planning and device positioning for left atrial appendage occlusion: insights from multi detector-row computed tomography with 3D fusion.

To compare planned and achieved device position in patients undergoing left atrial appendage occlusion (LAAO). It is unclear how devices used for LAAO position themselves compared to what is planned. All patients undergoing LAAO at our institution had pre- and post-procedural multi detector-row computed tomography (MDCT) at 3months (N = 52). Using dedicated software, both datasets were fused to superimpose the left atria in all planes. The effective device position was traced on the post-procedural MDCT and then imported in the pre-procedural dataset to allow comparisons. Planned and effective landing zones were compared with respect to size, location and orientation. The device's final position was in a significantly larger landing zone than planned (452 ± 174 vs. 351 ± 112 mm2 for effective and planned landing zones, respectively, paired t-test: p < 0.0001), resulting in significantly less-than-intended area oversizing (41 ± 31 vs. 12 ± 28%, p < 0.0001). In terms of device orientation, there was a difference of 19.7° between the planned and effective landing zones (p < 0.0001). The Amplatzer device had a shallower-than-planned position in 70% of cases, whereas the Watchman device had a deeper-than-planned position in 75% of cases (p = 0.04). Incomplete occlusion was found in 17 patients (33%). In a multivariable model, oversizing at the effective landing zone was the only MDCT independent predictor of incomplete occlusion (OR: 0.96 per 1% increment, 95% CI 0.95-0.98, p = 0.009). MDCT fusion showed that LAAO device position and orientation are different than planned, and this is associated with incomplete occlusion of the LAA.

Surgical Treatment of Recurrent Previously Coiled and/or Stent-Coiled Intracerebral Aneurysms: A Single-Center Experience in a Series of 75 Patients

Endovascular treated cerebral aneurysms have a greater recurrence rate compared with microsurgical clip ligation. Despite recent endovascular advances, microsurgical clip ligation might be the treatment of choice for certain previously endovascular treated recurrent aneurysms. We report on our single-center experience with 76 previously coiled and/or stent-coiled aneurysms. To analyze the surgical and radiologic outcome after clipping of previous endovascular treated recurrent cerebral aneurysms. Patients were retrospectively identified. Demographic data, aneurysm size, location, perioperative coil extraction, occlusion rate, and complication rate were recorded. Patients were divided into a previously coiled-only group (COG) and a previously stent-assisted coiled group (SAC). Seventy-five patients with 76 aneurysms were included. Sixty-nine patients were included in the COG, 7patients in the SAC group. Complete or acceptable near-complete occlusion was obtained in 95% of patients in the COG and 57% in the SAC group. Two patients in the COG (2.9%) died postoperatively of a major stroke. One patient died of rehemorrhage after wrapping of an aneurysm. Minor complications occurred in 8.7%. In the SAC group, the mortality was 0%, with 1 major stroke (14.2%), 1 minor stroke (14.2%), and 1 cranial nerve palsy (14.2%). Intraoperative coil extraction and previous stent-assisted coiling were significant predictors of complication rate (P= 0.025 and P= 0.0036 respectively). Previous stent-assisted coiling was a significant predictor of incomplete occlusion (P= 0.036). Microsurgical clipping of previously endovascular treated recurrent aneurysms is an effective treatment with high obliteration rates. Previously stent-assisted coiling and intraoperative coil extraction are predictors of worse outcome and incomplete occlusion.

Morphologic Feature Elongation Can Predict Occlusion Status Following Pipeline Embolization of Intracranial Aneurysms

To explore whether computed morphologic features can be used as independent predictors of incomplete occlusion of aneurysms treated with the Pipeline embolization device. From January 2016 to September 2017, 58 patients with 58 aneurysms were treated with the Pipeline embolization device. Aneurysms were manually segmented from the Digital Imaging and Communications in Medicine file, and we calculated 16 shape features voxel by voxel on the segmented aneurysm image. Along with 13 other clinical and radiographic variables, we performed univariate and multivariate analysis to explore predictors of incomplete occlusion. At last angiographic follow-up (median 6.2 months), complete occlusion was achieved in 41 aneurysms (70.7%). In multivariate analysis, malapposition of stent (odds ratio= 0.03; 95% confidence interval, 0.00-0.32; P=0.004) and higher elongation value (odds ratio= 0.03; 95% confidence interval, 0.01-0.17; P < 0.001) were independently associated with incomplete occlusion of aneurysms. Compared with aneurysms with complete occlusion, incompletely occluded aneurysms had higher elongation values (median 0.890 vs. 0.766; P < 0.001); the optimal cutoff value of elongation for occlusion status classification was 0.862. Predicting accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and area under the curve of the logistic regression model were 0.879, 0.902, 0.824, 0.925, 0.778, and 0.872. Malapposition of stent and higher elongation value were independent negative predictors of aneurysm occlusion following flow diversion.

Predictors of Incomplete Occlusion following Pipeline Embolization of Intracranial Aneurysms: Is It Less Effective in Older Patients?

Flow diversion with the Pipeline Embolization Device (PED) for the treatment of intracranial aneurysms is associated with a high rate of aneurysm occlusion. However, clinical and radiographic predictors of incomplete aneurysm occlusion are poorly defined. In this study, predictors of incomplete occlusion at last angiographic follow-up after PED treatment were assessed. A retrospective analysis of consecutive aneurysms treated with the PED between 2009 and 2016, at 3 academic institutions in the United States, was performed. Cases with angiographic follow-up were selected to evaluate factors predictive of incomplete aneurysm occlusion at last follow-up. We identified 465 aneurysms treated with the PED; 380 (81.7%) aneurysms (329 procedures; median age, 58 years; female/male ratio, 4.8:1) had angiographic follow-up, and were included. Complete occlusion (100%) was achieved in 78.2% of aneurysms. Near-complete (90%-99%) and partial (<90%) occlusion were collectively achieved in 21.8% of aneurysms and defined as incomplete occlusion. Of aneurysms followed for at least 12 months (211 of 380), complete occlusion was achieved in 83.9%. Older age (older than 70 years), nonsmoking status, aneurysm location within the posterior communicating artery or posterior circulation, greater aneurysm maximal diameter (≥21 mm), and shorter follow-up time (<12 months) were significantly associated with incomplete aneurysm occlusion at last angiographic follow-up on univariable analysis. However, on multivariable logistic regression, only age, smoking status, and duration of follow-up were independently associated with occlusion status. Complete occlusion following PED treatment of intracranial aneurysms can be influenced by several factors related to the patient, aneurysm, and treatment. Of these factors, older age (older than 70 years) and nonsmoking status were independent predictors of incomplete occlusion. While the physiologic explanation for these findings remains unknown, identification of factors predictive of incomplete aneurysm occlusion following PED placement can assist in patient selection and counseling and might provide insight into the biologic factors affecting endothelialization.

P4325Device position and predictors of incomplete occlusion after LAA closure: insights from 3D multi-slice computed tomography fusion imaging

P4325Device position and predictors of incomplete occlusion after LAA closure: insights from 3D multi-slice computed tomography fusion imaging

Abstract 8: The Pipeline Embolization Device: Midterm Results and Predictors of Outcomes in 335 Consecutive Patients

Introduction: Flow diversion has emerged as a promising treatment for intracranial aneurysms. The safety and efficacy of this new technology is under investigation. We present the largest single-center experience to date with the pipeline embolization device (PED) and identify several predictors of outcomes. Methods: The study includes 335 consecutive patients who underwent PED treatment at our institution between 2011-2015. Safety data was prospectively recorded both peri-operatively and through follow-up. Angiographic images were independently reviewed and aneurysm occlusion classified as complete (100%), near-complete (95-99%), or incomplete (&lt;95%). Results: Mean Aneurysm size was 9.4 mm. Aneurysms were saccular in 84% and fusiform/dissecting in 16%. Seventeen patients (5%) were treated in the setting of subarachnoid hemorrhage (SAH). The mean number of PEDs used was 1.2, and this number significantly decreased from 1.9 early in the study to 1.1 in the last year (p&lt;0.05). Complications occurred in 5% which included a 3.0% hemorrhagic complication rate, 1.5% thromboembolic complication rate, and 0.5% rate of PED migration. Predictors of complications were increasing aneurysm size, early discontinuation of dual antiplatelet therapy, and treatment in the setting of SAH. At follow-up (mean, 14 months), aneurysm occlusion was complete in 77.6%, near-complete in 9.1%, and incomplete in 13.3%. No patient had aneurysm recurrence. Predictors of incomplete occlusion were older patients, previously coiled/stented aneurysms, and MCA and posterior circulation aneurysms. At the latest follow-up, favorable outcomes (mRS 0-2) were noted in 95.7%. Neurologic mortality was 1.7% and neurologic morbidity was 1.2%. Multivariate predictors of poor outcome were early discontinuation of antiplatelet therapy, increasing aneurysm size, and increasing number of PEDs deployed. Conclusion: Treatment with the PED has an excellent safety-efficacy profile at large cerebrovascular centers. Several key factors associated with outcomes are discussed. Prolonged dual antiplatelet therapy is crucial for avoidance of complications. Off label locations are associated with lower occlusion rates. A single PED should be used whenever possible.