Single Pipeline Embolization Device Research Articles

Off-label in-silico flow diverter performance assessment in posterior communicating artery aneurysms.

The posterior communicating artery (PComA) is among the most common intracranial aneurysm locations, but flow diverter (FD) treatment with the widely used pipeline embolization device (PED) remains an off-label treatment that is not well understood. PComA aneurysm flow diversion is complicated by the presence of fetal posterior circulation (FPC), which has an estimated prevalence of 4-29% and is more common in people of black (11.5%) than white (4.9%) race. We present the FD-PComA in-silico trial (IST) into FD treatment performance in PComA aneurysms. ISTs use computational modeling and simulation in cohorts of virtual patients to evaluate medical device performance. We modeled FD treatment in 118 virtual patients with 59 distinct PComA aneurysm anatomies, using computational fluid dynamics to assess post-treatment outcome. Boundary conditions were prescribed to model the effects of non-fetal and FPC, allowing for comparison between these subgroups. FD-PComA predicted reduced treatment success in FPC patients, with an average aneurysm space and time-averaged velocity reduction of 67.8% for non-fetal patients and 46.5% for fetal patients (P<0.001). Space and time-averaged wall shear stress on the device surface was 29.2 Pa averaged across fetal patients and 23.5 Pa across non-fetal (P<0.05) patients, suggesting FD endothelialization may be hindered in FPC patients. Morphological variables, such as the size and shape of the aneurysm and PComA size, did not affect the treatment outcome. FD-PComA had significantly lower treatment success rates in PComA aneurysm patients with FPC. We suggest that FPC patients should be treated with an alternative to single PED flow diversion.

Treatment with a flow diverter-assisted coil embolization for ruptured blood blister-like aneurysms of the internal carotid artery: a technical note and analysis of single-center experience with pooled data.

Treatment of blood blister-like aneurysms (BBAs) of the supraclinoid internal carotid artery (ICA) with flow diverters (FDs) has become widespread in recent years. However, ruptured blood blister-like aneurysm (BBA) of ICA treatment with flow diverter-assisted coil embolization (FDAC) remains controversial. Moreover, limited direct comparative studies have been conducted between the two treatment modalities, FDs and FDAC, for BBAs. The purpose of this study was to document our experience and evaluate the effectiveness and safety of FDAC. We conducted a retrospective analysis of clinical and radiological information from ten patients who experienced ruptured BBAs of the supraclinoid ICA at our center from January 2021 to February 2023. The technical details of FDAC for ruptured BBAs were described, and the technical steps were named "pipeline embolization device (PED)-Individualized shaping(microcatheter)-Semi deploying-Rivet(coils)-Massage(microwire)" as the PEISSERM technique. Clinical outcomes were assessed using the modified Rankin Scale (mRS), whereas radiological results were determined through angiography. A pooled analysis was implemented, incorporating data from literature sources that reported perioperative and long-term clinical and angiographic outcomes of ruptured BBAs treated with FD and FDAC strategies, along with our data. Data in our analysis pool were categorized into FD and FDAC strategy groups to explore the preferred treatment modalities for BBAs. The PEISSERM technique was utilized to treat ten patients, seven males, and three females, with an average age of 41.7years. A single PED was deployed in conjunction with coils in all ten patients. All PEDs were documented to have good wall apposition. The immediate postoperative angiograms demonstrated Raymond grade I in ten aneurysms. Angiographic follow-up of nine patients at 4-25months showed total occlusion of the aneurysms. At the most recent follow-up, the mRS scores of nine patients hinted at a good prognosis. Pooled analysis of 233 ICA-BBA cases of FD revealed a technical success rate of 91% [95% confidence interval (CI), 0.88 to 0.95], a rate of complete occlusion of 79% (95% CI, 0.73 to 0.84), a recurrence rate of 2% (95% CI, 0.00 to 0.04), a rebleed rate of 2% (95% CI, 0.00 to 0.04), and the perioperative stroke rate was 8% (95% CI, 0.04 to 0.11). The perioperative mortality was 4% (95% CI, 0.01 to 0.07). The long-term good clinical outcome rate was 85% (95% CI, 0.80 to 0.90). The mortality rate was 6% (95% CI, 0.03 to 0.09). Results from the subgroup analysis illustrated that the FDAC strategy for BBAs had a significantly higher immediate postoperative complete occlusion rate (P < 0.001), total occlusion rate (P = 0.016), and a good outcome rate (P = 0.041) compared with the FD strategy. The FDAC strategy can yield a higher rate of good outcomes than the FD strategy. The PEISSERM technique employed by the FDAC is a reliable and effective treatment approach as it can minimize the hemodynamic burden of BBA's fragile dome, thereby achieving an excellent occlusion rate. The PEISSERM technique in the FDAC strategy contributes to understanding the BBA's treatment and offers a potentially optimal treatment for BBA.

Time Line of Occlusion for Intracranial Aneurysms Treated with the Pipeline Embolization Device

Rates of aneurysm occlusion following treatment with flow-diverting stents have been quantified at predefined time points in clinical trials, but data characterizing the continuous temporal progression of aneurysm occlusion are lacking. This study used real-world variability in timing of angiographic follow-up to characterize the time line of aneurysm occlusion following treatment with the Pipeline embolization device (PED). All aneurysms treated with a PED at our institution between 2011 and 2020 were screened. Nonsaccular or ruptured aneurysms were excluded. Aneurysm occlusion status and time since treatment were recorded for each follow-up angiogram. Aneurysm occlusion was characterized using Kaplan-Meier and Cox proportional hazards analysis after censoring at last follow-up or subsequent treatment. There were 290 aneurysms in 222 patients analyzed. The median time of observed aneurysm occlusion was 7.5 months, and overall rate of aneurysm occlusion was 77.9%. Larger aneurysms demonstrated a longer median time to occlusion and lower rate of aneurysm occlusion (P= 0.029). There were no observed differences in the time line of occlusion for aneurysms treated with a single PED or multiple PEDs (P= 0.889) or without or with adjunctive coiling (P= 0.771). Aneurysms treated with a PED had a median time to observed occlusion of 7.5 months. Occlusion of larger aneurysms occurred more slowly than occlusion of smaller aneurysms following flow diversion. The number of PEDs deployed or the use of adjunctive coiling did not affect the time line or likelihood of aneurysm occlusion. These findings may guide optimal timing of follow-up after treatment with a PED.

Impact of Endoluminal Flow Diverter Number on Aneurysm Treatment Outcomes: A Multicenter Study

Background The purpose of this study is to evaluate the impact multiple overlapping flow‐diverting stents have on aneurysm occlusion rates and iatrogenic complications relative to single flow‐diverting stents. Methods A retrospective review of a multicenter aneurysm database from 2012 to 2020 was performed to identify saccular aneurysms treated initially with single and multiple flow‐diverting stents with ≥12‐month angiographic and clinical follow‐up. Aneurysm occlusion rates as a function of stent number served as a primary outcome measure with iatrogenic complications serving as a secondary outcome measure. Results A total of 250 patients were initially treated with a single Pipeline embolization device (PED), and 48 patients were initially treated with multiple PEDs. There was no significant difference in aneurysm size, morphology, or dual‐antiplatelet therapy regimen used between groups. There was no significant difference in the aneurysm occlusion (single, 83.6%, versus multiple, 83.4%; P =0.65) or retreatment rates (single, 8.0%, versus multiple, 10.4%; P =0.58) between groups. There was no significant difference in the number of procedure‐related complications between groups (single, 8.0%, versus multiple, 4.2%; P =0.42), with 0.8% of patients treated with a single PED and 2.1% of patients treated with multiple PEDs experiencing a procedure‐related ischemic stroke. Conclusions There is no significant difference in overall aneurysm occlusion rates between aneurysms treated initially with single versus multiple overlapping PEDs nor are there significant differences in procedure‐related complications. Single PED flow diversion may be preferred whenever possible, with multiple PED constructs reserved for extenuating clinical circumstances as may be encountered with giant aneurysms.

Abstract WP11: The Impact Of Dual Antiplatelet Therapy Duration On Unruptured Aneurysm Occlusion Following Flow Diversion

Objective: The objective of this study is to assess the impact that the type and duration of DAPT has on aneurysm occlusion rates and iatrogenic complications following endoluminal flow diversion with a single flow diverting stent. Methods: A retrospective review of a multicenter aneurysm database was performed from 2012 to 2020 to identify unruptured intracranial aneurysms treated with single device flow diversion and &gt;12-month follow-up. Clinical and radiologic data were analyzed with aneurysm occlusion as a function of DAPT duration serving as a primary outcome measure. Results: A total of 205 patients underwent flow diversion with a single pipeline embolization device. During the study period, 12.7% of treated aneurysms remained non-occluded. There were no significant differences in aneurysm morphology or type of DAPT used between occluded and non-occluded groups. Non-occluded aneurysms received a longer mean duration of DAPT (9.4 vs 7.1 mo, p=0.016) with ANOVA demonstrating a significant effect of DAPT duration on the observed aneurysm occlusion rate (F(2, 202)=4.2, p=0.016). An exploratory analysis demonstrated the optimum DAPT discontinuation time to minimize aneurysm non-occlusion rates was 7.9 months (95% CI: 6-11 months). There was no significant difference in the rate of complications or delayed ischemic strokes observed between patients receiving short (&lt;6 mo) and prolonged duration (&gt;6 mo) DAPT (7.9% vs 9.3%, p=0.76). Conclusions: Following endovascular flow-diversion, an abbreviated duration of DAPT lasting 6 months may be most appropriate before transitioning to low-dose aspirin monotherapy to promote timely aneurysm occlusion while minimizing delayed thromboembolic complications.

Pipeline flex embolization device for the treatment of large unruptured posterior circulation aneurysms: Single-center experience

PurposeTo investigate the safety and effect of the Pipeline Embolization Device (PED) Flex device in the treatment of large unruptured posterior circulation aneurysms in a single center. Materials and methodsPatients with large unruptured posterior circulation aneurysms which were treated with the PED Flex device were enrolled. The clinical, endovascular and follow-up data were analyzed, and the O’Kelly-Marotta (OKM) grading system was used to assess the aneurysm occlusion status. ResultsFourteen patients with 14 large posterior circulation aneurysms who were treated with the PED Flex device were enrolled. The maximal diameter of aneurysm was 17.0 ± 3.9 mm. Fourteen PED Flex devices were deployed in 14 patients, with a technical success rate of 100%. All stents covered the aneurysm neck with good wall adherence and patent parent artery. Ten (71.4%) aneurysms were treated with a single PED Flex device each, and four (28.6%) patients experienced additional coiling. No neurological complications occurred in the periprocedural period. The mRS was 0 in eleven (78.6%) patients, 1 in two (14.3%), and 2 in one (7.1%) at discharge. All patients were followed up at 6–28 months (median 18), with an mRS score of 0 in all patients. Twelve (85.7%) patients experienced digital subtraction angiography 6–28 (median 18) months after the embolization procedure, and the OKM grade was D in nine (75%), C in two (16.7%), and B in one (8.3%). ConclusionThe Pipeline Flex Embolization Device can be safely applied to treat large unruptured posterior circulation aneurysms with a high complete aneurysm occlusion rate at follow-up.

Flow Diversion for Intracranial Aneurysms Beyond the Circle of Willis.

Background: Few reports have shown the therapeutic outcomes of flow diversion (FD) for intracranial aneurysms beyond the circle of Willis, and the efficacy of this technique remains unclear.Materials and methods: A retrospective study was performed on 22 consecutive patients, diagnosed with intracranial aneurysms beyond the circle of Willis, and treated with pipeline embolization device (PED) (Medtronic, Irvine, California, USA) between January 2015 and December 2019.Result: The 22 patients were between 16 and 66 years old (mean 44.5 ± 12.7 years), and six patients were male (27.3%, 6/22). Twenty-two patients had 23 aneurysms. The 23 aneurysms were 3–25 mm in diameter (12.2 ± 7.1 mm on average). The diameter of the parent artery was 1.3–3.0 mm (2.0 ± 0.6 mm on average). The 23 aneurysms were located as follows: 17 (73.9%, 17/23) were in the anterior circulation, and 6 (26.1%, 6/23) were in the posterior circulation. PED deployment was technically successful in all cases. Two overlapping PEDs were used to cover the aneurysm neck in 3 cases. One PED was used to overlap the two tandem P1 and P2 aneurysms. Other cases were treated with single PED. Coil assistance was used to treat 7 aneurysms, including 4 recurrent aneurysms and 3 new cases requiring coiling assistance during PED deployment. There were no cases of complications during PED deployment. All patients were available at the follow-up (mean, 10.9 ± 11.4 months). All patients presented with a modified Rankin Score (mRS) of 0. During angiographic follow-up, complete embolization was observed in 22 aneurysms in 21 patients, and one patient had subtotal embolization with the prolongation of stasis in the arterial phase.Conclusion: PED deployment for intracranial aneurysms beyond the circle of Willis is feasible and effective, with high rates of aneurysm occlusion.

Multiple pipeline embolization devices improves aneurysm occlusion without increasing morbidity: A single center experience of 140 cases

IntroductionRates of aneurysm occlusion with the pipeline embolization device (PED) has varied widely in the literature from 55.7% to 93.3% at 6 months, which may reflect a difference in technique including sizing and number of devices used. Methods140 cases at our institution were retrospectively reviewed, and aneurysms treated with a single PED vs. multiple were compared. ResultsComplete aneurysm occlusion was achieved in 86.9% at 6 months, 91.8% at 1 year, and 97.6% at longest follow-up. Retreatment with an additional device was required in 7 (5.1%). Major and minor complication rate within 30 days was 1.4% and 5.0%, and at greater than 30 days was 0.8% and 3.1%.Patients treated with multiple PEDs had significantly higher rates of aneurysm occlusion at 6 months (92.9% vs. 75.6%, p = 0.017) and 12 months (98.4% vs. 81.1%, p = 0.014), with no difference in complications. The two groups were similar aside from a higher number of ophthalmic and paraophthalmic aneurysms treated with multiple PEDs (23.4% vs. 6.5%, p = 0.004; and 35.1% vs. 17.4%, p = 0.020), and more posterior communicating artery and recurrent aneurysms treated with a single PED (28.3% vs. 3.2%, p = 0.001; 23.9% vs. 8.5%, p = 0.031). The use of multiple PEDs was found to be an independent predictor of aneurysm occlusion in a multivariate analysis (p = 0.015). ConclusionsThe use of multiple PEDs for intracranial aneurysms leads to significantly higher occlusion rates without added morbidity. This benefit is particularly appropriate for ophthalmic segment aneurysms, while more distal segments with eloquent perforating branches should be managed with caution.

Implications of the Collar Sign in Incompletely Occluded Aneurysms after Pipeline Embolization Device Implantation: A Follow-Up Study

The angiographic collar sign has been recently described in patients with incompletely occluded aneurysms after Pipeline Embolization Device implantation. The long-term implications of this sign are unknown. We report angiographic outcomes of patients with the collar sign with follow-up of up to 45 months and the implications of this angiographic finding. We performed a retrospective review of a prospectively maintained data base of patients who underwent Pipeline Embolization Device implantation for an intracranial aneurysm at our institution between January 2014 and December 2016. We included patients with a collar sign at the initial follow-up angiogram after Pipeline Embolization Device implantation. A total of 198 patients with 285 aneurysms were screened for the collar sign on initial and subsequent follow-up angiograms. There were 226 aneurysms (79.3%) with complete occlusion at the first follow-up. Of 59 incompletely occluded aneurysms, 19 (32.2%) aneurysms in 17 patients were found to have a collar sign on the first angiographic follow-up (median, 6 months; range, 4.2-7.2). Ten (52.6%) aneurysms underwent retreatment with a second Pipeline Embolization Device, which resulted in aneurysm occlusion in 1 (10%) patient. There were only 3 (15.8%) aneurysms with complete occlusion at the last follow-up, 2 (10.5%) of which had a single Pipeline Embolization Device implantation and another single (5.3%) aneurysm with a second Pipeline Embolization Device implantation. A collar sign on the initial angiogram after Pipeline Embolization Device placement is a predictor of poor aneurysm occlusion. Because the occlusion rates remain equally low regardless of retreatment in patients with a collar sign, radiologic follow-up may be more appropriate than retreatment.

Prospective study on embolization of intracranial aneurysms with the pipeline device: the PREMIER study 1 year results

BackgroundPreliminary clinical studies on the safety and efficacy of the pipeline embolization device (PED) for the treatment of small/medium aneurysms have demonstrated high occlusion rates with low complications.ObjectiveTo evaluate the...

Pipeline embolization device diameter is an important factor determining the efficacy of flow diversion treatment of small intracranial saccular aneurysms

ObjectiveFlow diversion using the Pipeline embolization device (PED) has become a widely used treatment method for intracranial aneurysms. However, a subset of aneurysms will fail to occlude following treatment and...

Hemodynamic impacts of flow diverter devices on the ophthalmic artery

BackgroundFlow diverter devices are increasingly used for endovascular treatment of internal carotid artery aneurysms. Treatment of ophthalmic segment aneurysms with flow diverter devices also includes coverage of the ophthalmic artery but may result in complications. It is unclear, however, whether these devices mechanically block blood flow in the ophthalmic artery. Also unclear is the relationship between deployment of a flow diverter device and post-treatment occlusion. We studied hemodynamic changes in the ophthalmic artery after deployment of a flow diverter device to determine the relationship between those changes and post-stent occlusion of the artery.MethodsWe analyzed hemodynamic modifications in the ophthalmic artery in 21 patients (19 women, 2 men; mean age 53.43 ± 7.32 years) treated by a single pipeline embolization device. Patient-specific geometries were determined from three-dimensional digital subtraction angiography and the stenting process was simulated. Computational fluid dynamics technology was used to analyze the change in ophthalmic artery hemodynamics. We compared pre-treatment and post-treatment flow velocity of the ophthalmic artery.ResultsAmong the 21 patients with aneurysms located in the ophthalmic segment, no ophthalmic artery occlusion was found during immediate or follow-up angiography. Post-stent flow velocity in the ophthalmic artery decreased from 0.35 ± 0.19 to 0.33 ± 0.20 m/s, with the difference not being statistically significant (P = 0.106).ConclusionOur results showed no significant change in ophthalmic artery blood flow after pipeline embolization device deployment. Hence, post-stent occlusion of the ophthalmic artery could not be explained by reduced blood flow. Delayed thrombosis and neointimal formation maybe the keys to ophthalmic artery occlusion and need further investigation.

Immediate Flow Disruption as a Prognostic Factor After Flow Diverter Treatment: Long-Term Experience with the Pipeline Embolization Device.

To report long-term results after Pipeline Embolization Device (PED) implantation, characterize complex and standard aneurysms comprehensively, and introduce a modified flow disruption scale. We retrospectively reviewed a consecutive series of 40 patients harboring 59 aneurysms treated with 54 PEDs. Aneurysm complexity was assessed using our proposed classification. Immediate angiographic results were analyzed using previously published grading scales and our novel flow disruption scale. According to our new definition, 46 (78%) aneurysms were classified as complex. Most PED interventions were performed in the paraophthalmic and cavernous internal carotid artery segments. Excellent neurologic outcome (modified Rankin Scale 0 and 1) was observed in 94% of patients. Our data showed low permanent procedure-related mortality (0%) and morbidity (3%) rates. Long-term angiographic follow-up showed complete occlusion in 81% and near-total obliteration in a further 14%. Complete obliteration after deployment of a single PED was achieved in all standard aneurysms with 1-year follow-up. Our new scale was an independent predictor of aneurysm occlusion in a multivariable analysis. All aneurysms with a high flow disruption grade showed complete occlusion at follow-up regardless of PED number or aneurysm complexity. Treatment with the PED should be recognized as a primary management strategy for a highly selected cohort with predominantly complex intracranial aneurysms. We further show that a priori assessment of aneurysm complexity and our new postinterventional angiographic flow disruption scale predict occlusion probability and may help to determine the adequate number of per-aneurysm devices.

Fatal Basilar Aneurysm Rupture 6 Months Following Pipeline Flow Diversion Treatment

Abstract Background Very delayed aneurysmal rupture represents a rare, poorly understood, catastrophic complication of intracranial aneurysm flow diversion (FD) treatment. Case Description A 48-year-old woman presented to the neurosurgical clinic for an elective admission 6-month post-FD treatment with a single pipeline embolization device (PED) treatment of a fusiform, large, midbasilar artery aneurysm. During her admission, the patient suffered a tonic-clonic seizure and collapsed. She was intubated and transferred for an urgent computed tomographic scan of the brain, which revealed subarachnoid hemorrhage and hydrocephalus. She was subsequently transferred to the operating room where an external ventricular drain was placed. Urgent diagnostic cerebral angiography revealed rupture of the previously treated aneurysm which was managed with deployment of a second PED and coil embolization of the right vertebral artery. Unfortunately, the patient succumbed to the disease 15 days later. Conclusion The pathophysiologic mechanism responsible for delayed aneurysmal rupture post-FD treatment remains to be defined and may involve an acute rise in intra-aneurysmal pressures in a partially thrombosed aneurysm, continued hemodynamic stress on the aneurysmal wall due to persistent blood inflow, and thrombus-induced inflammation-mediated degradation the aneurysmal wall. Further clinical and anatomical studies are necessary to define the mechanisms responsible for delayed aneurysm ruptures and identify appropriate preventive measures.

Treatment of Tandem Internal Carotid Artery Aneurysms Using a Single Pipeline Embolization Device: Evaluation of Safety and Efficacy.

Tandem aneurysms are defined as multiple aneurysms located in close proximity on the same parent vessel. Endovascular treatment of these aneurysms has rarely been reported. Our aim was to evaluate the safety and efficacy of a single Pipeline Embolization Device for the treatment of tandem aneurysms of the internal carotid artery. A retrospective analysis of consecutive aneurysms treated with the Pipeline Embolization Device between 2009 and 2016 at 3 institutions in the United States was performed. Cases included aneurysms of the ICA treated with a single Pipeline Embolization Device, and they were divided into tandem versus solitary. Angiographic and clinical outcomes were compared. The solitary group (median age, 58 years) underwent 184 Pipeline Embolization Device procedures for 184 aneurysms. The tandem group (median age, 50.5 years) underwent 34 procedures for 78 aneurysms. Aneurysms were primarily located along the paraophthalmic segment of the ICA in both the single and tandem groups (72.3% versus 78.2%, respectively, P = .53). The median maximal diameters in the solitary and tandem groups were 6.2 and 6.7 mm, respectively. Complete occlusion on the last angiographic follow-up was achieved in 75.1% of aneurysms in the single compared with 88.6%% in the tandem group (P = .06). Symptomatic thromboembolic complications were encountered in 2.7% and 8.8% of procedures in the single and tandem groups, respectively (P = .08). Tandem aneurysms of the ICA can be treated with a single Pipeline Embolization Device with high rates of complete occlusion. While there appeared to be a trend toward higher thromboembolic complication rates, this did not reach statistical significance.

Factors Affecting the Obliteration Rate of Intracranial Aneurysms Treated with a Single Pipeline Embolization Device.

To evaluate the clinical and angiographic outcomes of intracranial aneurysm treatment using a single Pipeline embolization device (PED), and to evaluate the factors affecting aneurysm obliteration rate. The demographic characteristics and anatomic features of 58 aneurysms in 47 patients treated with a single PED were reviewed retrospectively. All aneurysms treated with a PED at a single center and with follow-up angiograms for at least 6 months were included in this study. The overall rate of complete and near-complete occlusion was 84% (49 of 58) after a mean follow-up period of 18.3 months. The rate of complete aneurysm obliteration was lower in aneurysms with an arterial branch arising from the aneurysm neck compared with aneurysms without an arterial branch (13% [1 of 8] vs. 68% [34 of 50]; P= 0.0075). The overall rate of complete and near-complete aneurysm occlusion was 90% (45of 50) in aneurysms without an arterial branch arising from its neck. There were no statistically significant associations between obliteration rate and aneurysm neck width, size, or type, or history of previous coil embolization. Our data suggest that a single PED is sufficient to induce complete or near-complete obliteration of most aneurysms. The presence of a branching artery arising from the aneurysm neck is highly predictive of incomplete occlusion after treatment with a single PED.

Rescue Treatment with Pipeline Embolization for Postsurgical Clipping Recurrences of Anterior Communicating Artery Region Aneurysms

Background: Postsurgical clipping aneurysm recurrences or residuals can be difficult to manage with either traditional open microsurgical approaches or endosaccular coiling. Endoluminal parent vessel reconstruction with flow diversion may be an ideal method for treating these recurrences by avoiding reoperative surgery or intraprocedural aneurysm rupture with aneurysm access. Method: We retrospectively reviewed a single-center aneurysm database identifying all anterior communicating artery (ACom) region aneurysms with recurrences after microsurgical clipping. Cases subsequently treated with Pipeline embolization device (PED) were identified for analysis. Results: Nine PED neurointerventions were performed for the treatment of 6 ACom region recurrent aneurysms after surgical clipping (ACom, n = 4 and A1-A2 junction, n = 2). Of the 6 aneurysms treated, 4 were previously ruptured. Mean patient age was 59.5 ± 6.9 years (range 50-67 years). Mean aneurysm size was 5.1 ± 2.2 mm (range 3-9 mm). Mean fluoroscopy time was 44.1 ± 12.4 min. A single PED, deployed from ipsilateral A2 to ipsilateral A1, was used in 6 cases. No instances of periprocedural complications were encountered. Angiographic follow-up was available in all aneurysms; 5 of these 6 (83%) demonstrated complete aneurysm occlusion. Conclusion: Flow diversion with PED can be a safe and efficacious treatment approach for recurrent ACom region aneurysms after surgical clipping.

Treatment of distal anterior cerebral artery aneurysms with the Pipeline Embolization Device

Aneurysms of the anterior cerebral artery (ACA) located distal to the anterior communicating artery complex (ACOM) remain challenging to treat with surgical clip reconstruction as well as with endovascular coil-embolization strategies. We have treated five complex geometry distal ACA aneurysms with endoluminal reconstruction using the Pipeline Embolization Device (PED). Two aneurysms were of the dysplastic fusiform type. Three aneurysms were of complex saccular configuration. Three aneurysms were treated electively at the outset with PED. One patient had previously undergone aborted clip reconstruction, and one was treated for recurrent aneurysm growth after coil embolization. The mean diameter of the ACA in this cohort was 1.96mm proximal to the aneurysm and 1.79mm distal to the aneurysmal segment. A single PED of 2.5mm inner diameter was the sole treatment in four cases. Two PEDs, telescopically overlapped across the aneurysm, were used in the remaining case. All devices were deployed successfully. No parent artery occlusion or stenosis was observed. In all cases an associated branch vessel arising from the vicinity of the aneurysm or incorporated into its neck was covered by the endoluminal construct. At follow-up angiography, robust antegrade flow was maintained in the jailed branch. One patient experienced asymptomatic, delayed occlusion of the jailed branch. Complete aneurysm occlusion was seen in all patients. We confirm that PED can be deployed in parent vessels smaller than 2mm diameter, and that endoluminal reconstruction with the PED may be a safe and effective treatment alternative for selected distal ACA aneurysms.

Short-term follow up of pipeline embolization device (PED) deployment for treatment of intracranial carotid aneurysm

Objective To explore the technical skills and short-term efficacy of Pipeline Embolization Device (PED) deployment for endovascular treatment of complex intracranial carotid aneurysm. Methods The medical charts of 6 cases who underwent PED implant procedure in our institute from Jan. to Jun. 2015 were reviewed, including 4 female and 2 male; the mean age was (56 ± 13) years, ranging from 34–70 years. All the 6 cases suffered from intracranial carotid aneurysm and PED implant procedures were performed to cover the aneurismal neck under general anesthesia, while dual antiplatelet treatment (Bayaspirin + Plavix) was administered. The basic characteristics and peri-procedural adverse events were recorded, interview and mRS score were done by telephone 1 month after procedure, clinical examination and DSA angiographic re-check were made 3 months following procedure, respectively. Status of aneurysm occlusion was evaluated by Raymond grading scale. Results All 6 aneurysms involved were unruptured. Technical success was achieved in all procedures for 6 cases, of which 3 cases were single PED implantation and the other 3 PED adjuncted to coiling. No procedure related complication was detected during 30 days after operation. Follow up with 1.5–4.8 months (median 2.8 months) were conducted and last follow up revealed good outcome (mRS<2) in all cases. The control angiography showed contrast filling aneurismal sac even after PED implantation, DSA recheck performed in 2 cases at 3 months after operation and revealed good obstruction of aneurysm (Raymond grade≤2). Conclusion Domestic preliminary study shows PED implantation seems to be a safe and effective modality for treatment of complex intracranial carotid aneurysms. Key words: Intracranial aneurysm; Radiology, interventional; Treatment outcome

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.