Treatment of intracranial aneurysms by flow diverter devices: long-term results from a single center

Long-term outcomes of flow diversion for unruptured intracranial aneurysms: a systematic review and meta-analysis

BACKGROUND

Flow diverters have been widely used in clinical practice for more than a decade. However, most outcome data are limited to 1 year timepoints. This study aims to offer meta-analysis data on long-term (>1 year) safety and effectiveness results for patients with aneurysms treated with flow diverters.

METHODS

PubMed, Web of Science, Embase, and SCOPUS were searched up to February 24, 2022 using the AutoLit platform. We included primary studies assessing the long-term outcomes for flow diverter devices to manage unruptured internal carotid artery aneurysms with a follow-up period of >1 year. The meta-analysis was carried out using Comprehensive Meta-Analysis software (CMA).

RESULTS

Eleven studies were included in the meta-analysis. The pooled occlusion rates after flow diversion treatment for unruptured intracranial brain aneurysms were 77%, 87.4%, 84.5%, 89.4%, 96% for 1 year, 1-2 years, 2 years, 3 years, and 5 years follow-up, respectively. The in-stent stenosis rate was 4.8% and the retreatment rate for the long-term follow-up period was 5%. No delayed rupture of the aneurysm was reported, and there was one case of delayed ischemic stroke. The sensitivity analysis of the prospective studies showed a complete occlusion rate of 83.5% and 85.2% for 1 and 3 years of follow-up, respectively.

CONCLUSION

Flow diverters are safe and effective in short- and long-term follow-up and rarely cause serious delayed side effects.

Treatment of Traumatic Internal Carotid Artery Aneurysm by Flow-Diverter: A Single-Center Experience

AIM

Traumatic intracranial aneurysm (TICA) is a rare vascular lesion with various etiologies and a high mortality rate when diagnosed late. In this study, we present our cases of TICA, which we treated with flow-diverter stents due to different etiological factors.

METHODS

Clinical data were recorded for 8 patients: age, gender, etiological factors, aneurysm location, aneurysm type, rupture, main artery status, and postoperative complications.

RESULTS

75% (n:6) of the patients were male and 25% (n:2) female. Etiologically, there was intracranial tumor surgery in 3 cases (37.5%), fall from height in 2 (25%), road accident in 2 (25%), and blunt trauma in 1 (12.5%). Reconstruction used a flow-diverting stent in all cases. One patient experienced intraoperative iatrogenic rupture of the distal arterioles due to a microwire. Mean angiographic follow-up was 17.8 months (range, 6-32 months). During follow-up, none of the patients required renewed endovascular treatment.

CONCLUSION

Traumatic aneurysm is a vascular lesion with high mortality when diagnosed late. In case of suspected vascular injury after trauma or intracranial surgery, further evaluation should be performed without delay. TICA can be safely treated with flow-diverter stents, conserving the main artery.

Pipeline Embolization Stent for the Treatment of Giant Supraclinoid Aneurysms: A Case Series

Cerebrovascular aneurysms of the supraclinoid region are a technical challenge and can be particularly difficult to treat when greater than 25 mm in diameter. Such giant aneurysms can be approached with various skull-based and endovascular surgical techniques, and the advent of the Pipeline embolization stent presents a new treatment modality. Previously used for the treatment of small aneurysms, the Pipeline embolization device (PED) is a flow diverter device that has more recently been investigated in its use for the treatment of giant aneurysms with few studies to date published about its procedural outcomes. Here, we highlight the case of three patients (two elderly and one middle-aged) presenting symptomatically with giant supraclinoid aneurysms of the cavernous internal carotid artery (ICA) and posterior communicating artery treated with the Pipeline stent and monitored on follow-up visits. We further review the most current case reports and the two clinical trials to date investigating the utility of the Pipeline stent in the treatment of large and giant cerebral aneurysms, highlighting the emerging evidence of its efficacy and long-term patient outcomes. We report successful resolution of symptoms and radiographic evidence of aneurysm size reduction on all patient follow-ups and suggest the Pipeline embolization device as a novel technique that can be utilized for the treatment of giant cerebrovascular aneurysms with emerging evidence of immediate and long-term success.

Follow-up of Intracranial Aneurysms Treated by Flow Diverters: Evaluation of Parent Artery Patency Using 3D-T1 Gradient Recalled-Echo Imaging with 2-Point Dixon in Combination with 3D-TOF-MRA with Compressed Sensing

BACKGROUND AND PURPOSE

MRA assessment of parent artery patency after flow-diverter placement is complicated by imaging artifacts produced by these devices. The purpose of this study was to assess the accuracy of liver acquisition with volume acceleration-flex technique (LAVA-Flex) MRA in combination with 3D-TOF with HyperSense MRA for the evaluation of parent vessel status after intracranial flow-diverter placement.

MATERIALS AND METHODS

Fifty-six patients treated by flow diversion and followed with both DSA and 3T MRA between November 2020 and August 2021 were included. All patients were evaluated for parent artery patency using the same imaging protocol (DSA, noncontrast MRA including 3D-TOF with HyperSense and LAVA-Flex, and contrast-enhanced MRA, including time-resolved imaging of contrast kinetics MRA and delayed contrast-enhanced MRA).

RESULTS

With DSA as a criterion standard to evaluate the patency of the parent vessel, noncontrast MRA had a good specificity (0.83) and positive predictive value (0.65), better than contrast-enhanced MRA (0.55 and 0.41, respectively). Both had excellent sensitivity and negative predictive value: noncontrast MRA, 0.93 and 0.97, respectively; contrast-enhanced MRA, 0.93 and 0.96, respectively. Specificity and positive predictive value tended to be lower for patients treated with additional devices than for those treated with flow diverters exclusively and for patients treated with a specific type of flow diverter.

CONCLUSIONS

Noncontrast MRA can be used for noninvasive follow-up of intracranial aneurysms treated by flow diverters. The combined use of LAVA-Flex and 3D-TOF with HyperSense sequences allows monitoring the status of the parent artery and aneurysm occlusion.

Endovascular Treatment of Anterior Circulation Aneurysms With the p64 Flow Modulation Device: Mid- and Long-Term Results in 617 Aneurysms From a Single Center

BACKGROUND

Flow diverters have become an important tool in the treatment of intracranial aneurysms, especially when dealing with difficult-to-treat or complex aneurysms. The p64 is the only fully resheathable and mechanically detachable flow diverter available for clinical use.

OBJECTIVE

To evaluate the safety and effectiveness of p64 for the treatment of intracranial saccular unruptured aneurysms arising from the anterior circulation over a long-term follow-up period.

METHODS

We retrospectively reviewed our prospectively maintained database to identify all patients who underwent treatment for an intracranial saccular (unruptured or beyond the acute hemorrhage phase) aneurysm arising from the anterior circulation with ≥1 p64 between December 2011 and December 2019. Fusiform aneurysms and dissections were excluded. Aneurysms with prior or concomitant saccular treatment (eg, coiling and clipping) were included. Aneurysms with parent vessel implants other than p64 were excluded. Anatomic features, intraprocedural complications, clinical outcome, as well as clinical and angiographic follow-ups were all recorded.

RESULTS

In total, 530 patients (388 females; median age 55.9 yr) with 617 intracranial aneurysms met the inclusion criteria. The average number of devices used per aneurysm was 1.1 (range 1-3). Mean aneurysm dome size was 4.8 mm (range 1-27 mm). Treatment-related morbimortality was 2.4%. Early, mid-term, and long-term angiographic follow-up showed complete or near-complete aneurysm occlusion in 76.8%, 89.7%, and 94.5%, respectively.

CONCLUSION

Treatment of intracranial saccular unruptured aneurysms of the anterior circulation using p64 is a safe and effective treatment option with high rate of occlusion at long-term follow-up and low morbimortality.

Propensity Score Analysis of Flow Diverters Placed in Scaffolding Stents

BACKGROUND AND PURPOSE

Flow-diverter deployment within a stent remains controversial, but flow-diverter deployment within a scaffolding stent has been performed occasionally. To date, an analysis of this scaffolding technique has not been reported. We aimed to evaluate whether the scaffolding technique adversely affects the outcomes of flow diversion.

MATERIALS AND METHODS

Patients who had undergone intracranial aneurysm treatment using a Silk flow diverter with (scaffolding group) or without (bare flow-diverter group) a scaffolding stent were identified retrospectively and compared. Propensity score matching was used to match the aneurysms in both groups for variables with a significant difference between groups. Aneurysm occlusion rates and clinical outcomes were compared.

RESULTS

There were 84 patients (105 aneurysms) in the bare flow-diverter group and 21 patients (22 aneurysms) in the scaffolding group (using 20 LEO stents and 1 Enterprise stent). The aneurysms in the scaffolding group were larger (mean, 13.1 [SD, 10.7] versus 7 [SD, 4.5] mm, P = .001) and more likely to be fusiform (40.9% versus 5.7%, P < .001) than in the bare flow-diverter group. After 2:1 propensity score matching, 24 aneurysms in the bare flow-diverter group and 15 in the scaffolding group were matched. Aneurysm occlusion rates did not significantly differ between groups at 1-3 months (41.2 versus 33.3%, P > .99), 3-6 months (55.5 versus 75.0%, P = .44), 7-12 months (65.0 versus 90.0%, P = .21), or beyond 1 year (73.6 versus 91.6%, P = .36). There was no difference in complication rates between the groups (P > .99).

CONCLUSIONS

Placement of a scaffolding stent before flow diversion does not adversely affect aneurysm occlusion or complication rates.

Flow Diversion for Treatment of Acutely Ruptured Intracranial Aneurysms : A Single Center Experience from 45 Consecutive Cases

BACKGROUND

Reports about the use of flow diverter stents (FDS) in the acute setting of subarachnoid hemorrhage (SAH) are limited. This article presents a single center experiences based on 45 consecutive cases with emphasis on complication rates and clinical and radiologic outcomes.

METHODS

A prospectively maintained database of all cases treated with FDS as a stand-alone or adjunct device was retrospectively reviewed. All patients treated within 30 days of SAH were included. Records were made of clinical presentation, details of endovascular treatment, procedural complications, clinical outcome, and degree of occlusion on follow-up.

RESULTS

In this study 45 patients (48.9% females; mean age 58.8 ± 12.4 years) were included. Flow diversion was performed after a median of 4 days. The procedural complication rate was 13.3% resulting in 2.2% permanent morbidities and 4.4% mortalities. No major hemorrhagic complications related to antiplatelet therapy were recorded. Immediate complete occlusion was achieved in 13.3%. Among survivors, complete occlusion was achieved in 94.6%. Excellent clinical outcome was recorded in 68.9% and 81.6% of the total population and survivors, respectively. There were no records of rebleeding from the target lesions.

CONCLUSION

Flow diversion is an attractive alternative strategy for management of acutely ruptured aneurysms with high rates of delayed complete occlusion and acceptable complication rates.

Failure of Flow Diverter Therapy: Predictors and Management Strategies

Flow diversion is a safe and effective treatment for many types of brain aneurysms. Even so, there remain some aneurysms that persist despite initial treatment. In studies with the longest follow-up (5 yr), at least 5% of aneurysms persist with this treatment modality. As the cumulative experience and clinical indications for flow diversion continue to expand, the anatomic and functional characteristics that are associated with aneurysm persistence are increasingly described. Identification of these factors preoperatively can help to guide initial treatment decisions, enhance monitoring protocols in the follow-up period, and establish best practices for re-treatment when necessary. Herein, we review published clinical series and provide examples to highlight variables implicated in aneurysm persistence after treatment with flow diversion.

TREATMENT OF INTERNAL CAROTID ANEURYSMS USING PIPELINE EMBOLIZATION DEVICES: MEASURING THE RADIATION DOSE OF THE PATIENT AND DETERMINING THE FACTORS AFFECTING IT

The purpose of this study was to measure the peak skin dose (PSD) and bilateral lens doses using radiophotoluminescence glass dosimeters and to determine the factors influencing the radiation dose in cases of cerebral aneurysm treated with pipeline embolization devices (PEDs). The cumulative dose, PSD and right and left lens doses were 3818.1 ± 1604.6, 1880.0 ± 723.0, 124.8 ± 49.2 and 180.7 ± 124.8 mGy, respectively. Using multivariate analysis, body mass index (p < 0.01; odds ratio (OR) = 1.806; 95% confidence interval (CI) = 1.007-3.238) and deployment time of PED (p < 0.05; OR = 1.107; 95% CI = 1.001-1.224) were found to be the independent predictors of PSD exceeding 2 Gy. Measures such as collimation of the radiation field and optimization of radiation dose should be taken to reduce the radiation to the patient.

Large Neck and Strong Ostium Inflow as the Potential Causes for Delayed Occlusion of Unruptured Sidewall Intracranial Aneurysms Treated by Flow Diverter

BACKGROUND AND PURPOSE

Flow diverter-induced hemodynamic change plays an important role in the mechanism of intracranial aneurysm occlusion. Our aim was to explore the relationship between aneurysm features and flow-diverter treatment of unruptured sidewall intracranial aneurysms.

MATERIALS AND METHODS

MR imaging, 4D phase-contrast, was prospectively performed before flow diverter implantation in each patient with unruptured intracranial aneurysm. Two postprocedure follow-ups were scheduled at 6 and 12 months. Responses were grouped according to whether the aneurysms were occluded or remnant. Preprocedural aneurysm geometries and ostium hemodynamics in 38 patients were compared between the 2 groups at 6 and 12 months. Receiver operating characteristic curve analyses were performed for significant geometric and hemodynamic continuous parameters.

RESULTS

After the 6-month assessment, 21 of 41 intracranial aneurysms were occluded, and 9 additional aneurysms were occluded at 12 months. Geometrically, the ostium maximum diameter was significantly larger in the remnant group at 6 and 12 months (both P < .001). Hemodynamically, the proximal inflow zone was more frequently observed in the remnant group at 6 months. Several preprocedural ostium hemodynamic parameters were significantly higher in the remnant group. As a prediction for occlusion, the areas under the curve of the ostium maximum diameter (for 6 and 12 months), systolic inflow rate ratio (for 6 months), and systolic inflow area (for 12 months) reached 0.843, 0.883, 0.855, and 0.860, respectively.

CONCLUSIONS

Intracranial aneurysms with a large ostium and strong ostium inflow may need a longer time for occlusion. Preprocedural 4D flow MR imaging can well illustrate ostium hemodynamics and characterize aneurysm treatment responses.

Predictors of cerebral aneurysm persistence and occlusion after flow diversion: a single-institution series of 445 cases with angiographic follow-up

OBJECTIVE Flow diversion requires neointimal stent overgrowth to deliver aneurysm occlusion. The existing literature on aneurysm occlusion is limited by heterogeneous follow-up, variable antiplatelet regimens, noninvasive imaging modalities, and nonstandard occlusion assessment. Using a large, single-center cohort with low attrition and standardized antiplatelet tapering, the authors evaluated outcomes after flow diversion of anterior circulation aneurysms to identify predictors of occlusion and aneurysm persistence. METHODS Data from a prospective, IRB-approved database was analyzed for all patients with anterior circulation aneurysms treated by flow diversion with the Pipeline embolization device (PED) at the authors' institution. Follow-up consisted of catheter cerebral angiography at 6 and 12 months postembolization. Clopidogrel was discontinued at 6 months and aspirin was reduced to 81 mg daily at 12 months. Occlusion was graded as complete, trace filling, entry remnant, or aneurysm filling. Multivariate logistic regression was performed to identify predictors of aneurysm persistence. RESULTS Follow-up catheter angiography studies were available for 445 (91%) of 491 PED procedures performed for anterior circulation aneurysms between August 2011 and August 2016. Three hundred eighty-seven patients accounted for these 445 lesions with follow-up angiography. The population was 84% female; mean age was 56 years and mean aneurysm size was 6.6 mm. Aneurysms arose from the internal carotid artery (83%), anterior cerebral artery (13%), and middle cerebral artery (4%). Morphology was saccular in 90% of the lesions, and 18% of the aneurysms has been previously treated. Overall, complete occlusion was achieved in 82% of cases at a mean follow-up of 14 months. Complete occlusion was achieved in 72%, 78%, and 87% at 6, 12, and 24 months, respectively. At 12 months, adjunctive coiling predicted occlusion (OR 0.260, p = 0.036), while male sex (OR 2.923, p = 0.032), aneurysm size (OR 3.584, p = 0.011), and incorporation of a branch vessel (OR 2.206, p = 0.035) predicted persistence. Notable variables that did not predict aneurysm occlusion were prior treatments, vessel of origin, fusiform morphology, and number of devices used. CONCLUSIONS This is the largest single-institution study showing high rates of anterior circulation aneurysm occlusion after Pipeline embolization. Predictors of persistence after flow diversion included increasing aneurysm size and incorporated branch vessel, whereas adjunctive coiling predicted occlusion.

Long-term results of flow diversion in the treatment of intracranial aneurysms: a retrospective data analysis of a single center

PURPOSE

Endovascular techniques are frequently used for the treatment of intracranial aneurysms and flow diverter stents are relatively new and important devices in this field. The aim of our study is to report long-term follow-up results of flow diversion treatment.

METHODS

We retrospectively examined angiographic images and clinical reports of 133 patients (female, 112 [84%]; mean age, 46.3 years [range, 12-70 years]) who were treated with flow diverters between 2008 and 2013 and were followed up radiologically at least 1 year. The aneurysms treated with flow diverters were assessed according to technical problems, stent patency, residual filling, re-growth, and occlusion status, and the patients were assessed according to morbidity and mortality.

RESULTS

Except for ten patients, one aneurysm was treated per patient. Median duration of the follow-up was 927 days. Total occlusion rates in angiographic follow-up were found 76.2% for the sixth-month, 86.7% for the first-year, 93.6% for the third-year, 94.2% for the fifth-year, and 90.2% for entire follow-up period. Nine stent morphology changes were observed in the angiographic controls. Overall mortality and morbidity rates were 3.7% and 4.3%, respectively.

CONCLUSION

Despite technical difficulties and delayed hemorrhages, flow diverter stents are effective tools for the treatment of challenging aneurysms in the long run. Nonetheless, long-term results of flow diversion treatment must be evaluated hemodynamically and clinically in multicenter studies.

Pipeline Endovascular Device vs Stent-Assisted Coiling in Small Unruptured Aneurysms: A Cost-Effectiveness Analysis

BACKGROUND

Both stent-assisted coiling (SAC) and flow diversion with the Pipeline Embolization device (PED; Medtronic Inc) have been shown to be safe and clinically effective for treatment of small (<10 mm) unruptured aneurysms. However, the economic impact of these different techniques has not been established.

OBJECTIVE

To analyze the cost-effectiveness between stent-assisted coiling and flow diversion using PED, including procedural costs, long-term outcomes, and aneurysm recurrence.

METHODS

A decision-analytical study was performed with Markov modeling methods to simulate patients undergoing SAC or PED for treatment for unruptured aneurysms of sizes 5 and 7 mm. Input probabilities were derived from prior literature, and 1-way, 2-way, and probabilistic sensitivity analyses (PSA) were performed.

RESULTS

In base case calculation and PSA, PED was the dominant strategy for both the size groups, with and without consideration of indirect costs. One-way sensitivity analyses show that the conclusion remained robust when varying the retreatment rate of SAC from 0% to 50%, and only changes when the retreatment rate of PED > 49%. PED remained the more cost-effective strategy when the morbidity and mortality of PED increased by <55% and when those of SAC decreased by <37%. SAC only became cost-effective when the total cost of PED is >$73000 more expensive than the total cost of SAC.

CONCLUSION

With increasing use of PED for treatment of small unruptured anterior circulation aneurysms, our study indicates that PED is cost-effective relative to stent coiling irrespective of aneurysm size. This is due to lower aneurysm recurrence rate, as well as better health outcomes.

Comparative effectiveness analysis of Pipeline device versus coiling in unruptured aneurysms smaller than 10 mm

OBJECTIVE

Both endovascular coiling and the Pipeline embolization device (PED) have been shown to be safe and clinically effective for treatment of small (< 10 mm) aneurysms. The authors conducted a comparative effectiveness analysis to compare the utility of these treatment methods in terms of health benefits.

METHODS

A decision-analytical study was performed with Markov modeling methods to simulate patients with small unruptured aneurysms undergoing endovascular coiling, stent-assisted coiling (SAC), or PED placement for treatment. Input probabilities were derived from prior literature, and 1-way, 2-way, and probabilistic sensitivity analyses were performed to assess model and input parameter uncertainty.

RESULTS

The base case calculation for a 50-year-old man reveals PED to have a higher health benefit (17.48 quality-adjusted life years [QALYs]) than coiling (17.44 QALYs) or SAC (17.36 QALYs). PED is the better option in 6020 of the 10,000 iterations in probabilistic sensitivity analysis. When the retreatment rate of PED is lower than 9.53%, and the coiling retreatment is higher than 15.6%, PED is the better strategy. In the 2-way sensitivity analysis varying the retreatment rates from both treatment modalities, when the retreatment rate of PED is approximately 14% lower than the retreatment rate of coiling, PED is the more favorable treatment strategy. Otherwise, coiling is more effective. SAC may be better than PED when the unfavorable outcome risk of SAC is lower than 70% of its reported current value.

CONCLUSIONS

With the increasing use of PEDs for treatment of small unruptured aneurysms, the current study indicates that these devices may have higher health benefits due to lower rates of retreatment compared to both simple coiling and stent-assisted techniques. Longer follow-up studies are needed to document the rates of recurrence and retreatment after coiling and PED to assess the cost-effectiveness of these strategies.

Delayed parent artery occlusions following use of SILK flow diverters for treatment of intracranial aneurysms

Background

The efficacy of SILK flow diverters (SFD) in the management of cerebral aneurysms has been established. However, the risk of complications with parent artery occlusion (PAO) remains to be fully elucidated. The purpose of our study was to analyze intracranial aneurysms treated with SFDs and assess for occurrences and potential risk factors for PAO.

Materials and methods

Between September 2010 and September 2017, 34 patients were treated for intracranial aneurysms using SFDs at a Canadian institution. This database was retrospectively analyzed for frequency of PAOs and statistical analysis performed for potential contributing factors.

Results

Following treatment with SFDs, average clinical and imaging follow-ups were 31 and 22 months, respectively. PAOs were identified in 21% (7/34) of patients and occurred between 8 days and 1.5 years from intervention but only in 11.8% in those compliant to anti-platelet medications. These were all associated with anterior circulation aneurysms (P=0.131) and had no associated neurological deficits. Of these, 57% (4/7) had a fusiform morphology compared with only 19% (5/27) in non-occluded patients (P=0.039). The presence of clinical symptoms at the time of initial SFD intervention was significantly associated with PAO (P=0.021).

Conclusion

Delayed PAO is not an uncommon outcome of flow diverter deployment and could be seen up to 1.5 years after treatment with no associated neurological deficits. Anti-platelet non-adherence remains a risk factor for PAO. Fusiform morphology of the aneurysm and symptoms at the time of intervention were associated with subsequent occlusion.

Pipeline-assisted coiling versus pipeline in flow diversion treatment of intracranial aneurysms

BACKGROUND AND PURPOSE

Flow-diversion therapy (FDT) for large and complex intracranial aneurysms is effective and considered superior to primary coil embolization. Data evaluating common treatment with both FDT and coiling continues to emerge, but information on outcomes remains scarce. This study aims to examine further the efficiency and outcomes correlated with joint FDT using pipeline embolization device (PED) and coiling compared to PED-alone in treating intracranial aneurysms.

MATERIALS AND METHODS

Comparative review and analysis of aneurysm treatment with PED in 416 subjects were conducted. Joint modality, PED, and coiling were compared to PED-alone for aneurysm occlusion, recurrence, retreatment, thromboembolic or hemorrhagic events, and functional outcome using the modified Rankin Scale. Data on patient demographics, aneurysm characteristics, clinical and angiographic follow up, were also collected. Both univariate analysis and multivariate logistic regression modeling using mixed-effects were performed.

RESULTS

Total of 437 aneurysms were treated using PED of which 74 were managed with both PED and coiling. Average patient-age was 56 years, the majority were men (85%), an average aneurysm size was 9 mm, and the majority were saccular aneurysms (84%). Larger aneurysm size was associated with a poor outcome in patients with unruptured aneurysms (OR = 1.06). Adjusted regression analyses revealed no differences between treatment groups in thromboembolic or hemorrhagic events, aneurysm occlusion rate, residual flow on follow up angiography, or functional outcome.

CONCLUSIONS

Treatment of intracranial aneurysms with joint PED and coiling was safe with no increase in complications when compared to PED alone. Aneurysm occlusion rates and functional outcome with PED and coiling stays comparable to treatment with PED-alone.

Use of Pipeline™ embolization device for the treatment of traumatic intracranial pseudoaneurysms: Case series and review of cases from literature

OBJECTIVE

Intracranial traumatic pseudoaneurysms (PSA) are a rare but dangerous subtype of cerebral aneurysm. Reports documenting use of flow-diverting stents to treat traumatic intracranial PSAs are few and lack long-term follow-up. To our knowledge, this is the largest case-series to date demonstrating use of Pipeline Endovascular Device (PED) for traumatic intracranial PSAs.

PATIENTS AND METHODS

Retrospective review of 8 intracranial traumatic PSAs in 7 patients treated using only PED placement. Patients were followed clinically and angiographically for at least 6 months.

RESULTS

Seven patients with a mean age of 37 years were treated for 8 intracranial pseudo-aneurysms between 2011-2015. Six aneurysms were the result of blunt trauma; 2 were from iatrogenic injury during transsphenoidal surgery. Mean clinical and angiographic follow-up in surviving patients was 15.2 months. In patients with angiographic follow-up, complete occlusion was achieved in all but one patient, who demonstrated near-complete occlusion. No ischemic events or stent-related stenosis were observed. One patient developed a carotid-cavernous fistula after PED, which was successfully retreated with placement of a second PED. There were two mortalities. One was due to suspected microwire perforation remote from the target aneurysm resulting in SAH/IPH. The other was due to a traumatic SDH and brainstem hemorrhage from an unrelated fall during follow-up interval.

CONCLUSIONS

Use of PED for treatment of intracerebral PSAs following trauma or iatrogenic injury showed good persistent occlusion, and acceptable complication rate for this high-risk pathology. Risks of this procedure and necessary antiplatelet therapy require appropriate patient selection. Larger prospective studies are warranted.

Safety and Efficacy of Flow Diverter Treatment for Aneurysm in Small Cerebral Vessels: A Systematic Review and Meta-Analysis

PURPOSE

To clarify the safety and efficacy of flow diverter (FD) treatment for aneurysm in small cerebral vessels, we conducted a systematic review of the literature analyzing perioperative and long-term clinical and angiographic outcomes.

METHODS

A comprehensive review of the up-to-date literature for studies with ≥10 patients related to FD treatment of small vessel aneurysms published was performed. Random-effects meta-analysis was used to pool the following outcomes: complete occlusion, technical procedural success, perioperative mortality, perioperative stroke, procedure-related morbidity and mortality, all complications, long-term mortality, and overall good outcome.

RESULTS

We included 26 noncomparative studies with 572 target aneurysms. The technical procedural success rate was 96% (95% confidence interval [CI] 0.93-1.00). At final follow-up, the complete occlusion rate was 70% (95% CI 0.64-0.76). The all-cause morbidity rate was 20% (95% CI 0.14-0.25). Procedure-related morbidity and mortality rates were 9% (95% CI 0.07-0.12) and 4% (95% CI 0.00-0.08), respectively. Overall long-term good outcome rate was 96% (95% CI 0.93-0.99). In the 3 subgroup analyses, complete occlusion rate of saccular aneurysms was lower than that of nonsaccular aneurysms (55% vs. 73%, respectively; odds ratio 0.40, 95% CI 0.17-0.98, P = 0.04). The procedure-related morbidity rate and the good outcome rate were not significantly different in this subgroup. In the other 2 subgroups in which we compared anterior circulation aneurysms with posterior circulation aneurysms and single FD strategy with overlapped FD strategy, the rates were also not significantly different.

CONCLUSIONS

Our meta-analysis demonstrated that FD treatment of small vessel aneurysms is technically feasible and effective with a high rate of complete occlusion. Although the comorbidities of patients cannot be neglected, the FD approach was associated with an acceptable rate of procedure-related morbidity and a satisfactory rate of overall good outcome.

Radiofrequency ablation of osteoid osteoma

Osteoid osteoma is a benign bone neoplasm with a reported incidence of 2-3% among all bone primary tumors. Although it is a small and benign lesion, it is often cause of patient complaint and discomfort. It is generally characterized by a long lasting, unremitting pain that typically exacerbates at night, often leading to sleep deprivation and functional limitation of the skeletal segment involved, with a significant reduction of patient daily life activities and consequent worsening of the overall quality of life. Over decades, complete surgical resection has represented the only curative treatment for symptomatic patients. In the last years, new percutaneous ablation techniques, especially radiofrequency ablation, have been reported to be a safe and effective alternative to classical surgery, with a low complication and recurrence rate, and a significant reduction in hospitalization cost and duration. The aim of this article is to provide an overview about the radiofrequency thermal ablation procedure in the treatment of osteoid osteoma. (www.actabiomedica.it)

Developments in the management of bone metastases with interventional radiology

Interventional radiology has known an exponential growth in the last years. Technological advances of the last decades, have made it possible to use new treatments on a larger scale, with safe and effective results. They could be considered as palliative treatments for painful lesions but also curative procedures, as single treatment or specially in combination with other techniques (surgery, radiation and oncology therapies, etc.). The main diffuse techniques are those of thermal ablation that destroy the target lesion through the heat; however there are also endovascular therapies that destroy the target tissue thanks to devascularization. Finally the is also the possibility to stabilize pathological fractures or impending fractures. In this paper all the most diffuse and effective techniques are reviewed and also a discussion of the main indications is done, with an analisys of the success and complications rates. (www.actabiomedica.it)

Treatment of Middle Cerebral Artery Aneurysms with Flow-Diverter Stents: A Systematic Review and Meta-Analysis

BACKGROUND

The safety and efficacy of flow-diversion treatment of MCA aneurysms have not been well-established.

PURPOSE

Our aim was to evaluate angiographic and clinical outcomes after flow diversions for MCA aneurysms.

DATA SOURCES

A systematic search of PubMed, MEDLINE, and Embase was performed for studies published from 2008 to May 2017.

STUDY SELECTION

According to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we selected studies with >5 patients describing angiographic and clinical outcomes after flow-diversion treatment of MCA aneurysms.

DATA ANALYSIS

Random-effects meta-analysis was used to pool the following outcomes: aneurysm occlusion rate, procedure-related complications, rupture rate of treated aneurysms, and occlusion of the jailed branches.

DATA SYNTHESIS

Twelve studies evaluating 244 MCA aneurysms were included in this meta-analysis. Complete/near-complete occlusion was obtained in 78.7% (95% CI, 67.8%-89.7%) of aneurysms. The rupture rate of treated aneurysms during follow-up was 0.4% per aneurysm-year. The rate of treatment-related complications was 20.7% (95% CI, 14%-27.5%), and approximately 10% of complications were permanent. The mortality rate was close to 2%. Nearly 10% (95% CI, 4.7%-15.5%) of jailed arteries were occluded during follow-up, whereas 26% (95% CI, 14.4%-37.6%) had slow flow. Rates of symptoms related to occlusion and slow flow were close to 5%.

LIMITATIONS

Small and retrospective series could affect the strength of the reported results.

CONCLUSIONS

Given the not negligible rate of treatment-related complications, flow diversion for MCA aneurysms should be considered an alternative treatment when traditional treatment methods are not feasible. However, when performed in this select treatment group, high rates of aneurysm occlusion and protection against re-rupture can be achieved.

Safety and efficacy of the Pipeline embolization device for treatment of intracranial aneurysms: a pooled analysis of 3 large studies

OBJECTIVE

The authors performed a pooled analysis of 3 studies—IntrePED (International Retrospective Study of the Pipeline Embolization Device), PUFS (Pipeline for Uncoilable or Failed Aneurysms Study), and ASPIRe (Aneurysm Study of Pipeline in an Observational Registry)—in order to assess angiographic outcomes and clinical safety of the Pipeline embolization device (PED).

METHODS

IntrePED was a retrospective study, while PUFS and ASPIRe were prospective studies. For each patient included in these studies, the authors collected baseline demographic data, aneurysm characteristics, and procedural details. The primary outcomes for this combined analysis were clinical outcomes, including neurological morbidity and mortality and major ipsilateral intracranial hemorrhage and ischemic stroke. The secondary outcomes were angiographic occlusion rates, which were available for ASPIRe and PUFS only.

RESULTS

A total of 1092 patients with 1221 aneurysms were included across the 3 studies. The mean aneurysm size was 12.0 ± 7.8 mm and the mean neck size was 6.6 ± 4.8 mm. The major ipsilateral ischemic stroke rate was 3.7% (40/1091). The major ipsilateral intracranial hemorrhage rate was 2.0% (22/1091). The major neurological morbidity rate was 5.7% (62/1091). The neurological mortality rate was 3.3% (36/1091). The combined major morbidity and neurological mortality rate was 7.1% (78/1091). The complete occlusion rates were 75.0% at 180 days (111/148) and 85.5% at 1 year (94/110). The overall aneurysm retreatment rate was 3.0% (33/1091) at a mean follow-up time of 10.2 ± 10.8 months.

CONCLUSIONS

Endovascular treatment of intracranial aneurysms with the PED is safe and effective. Angiographic occlusion rates progressed with follow-up. Rates of stroke, hemorrhage, morbidity and mortality, and retreatment were low, especially given the fact that the aneurysms treated were generally large and wide necked.

Intracranial Aneurysms Treated by Flow-Diverting Stents: Long-Term Follow-Up with Contrast-Enhanced Magnetic Resonance Angiography

PURPOSE

Long-term data on aneurysm treatment with flow-diverting stents are still sparse, and follow-up protocols differ widely between institutions. We present long-term results, with a focus on the usefulness of contrast-enhanced MR angiography (ceMRA).

MATERIALS AND METHODS

Interventions and follow-up imaging of patients with aneurysms treated by flow-diverting stents ("Pipeline," "Silk" and "FRED" models) without additional coiling were analyzed. All MRI scans included dedicated two-phase ceMRA. Aneurysm occlusion rates, size of the aneurysmal sac and complications were evaluated on MRI and digital subtraction angiography (DSA), where available. The ability of ceMRA to depict aneurysm occlusion and stent patency was graded on a three-point scale.

RESULTS

Twenty-five patients with 102 MRI scans were included. The median duration of follow-up was 830 days. Aneurysm occlusion rates were 52% at 3 months (10 of 19 patients), 72% at 6 months (18/25) and 84% overall (21/25). Shrinkage of the aneurysmal sac was found in 19 patients (76%) and in 12 cases to <50% of the original size (48%). CeMRA assessability of aneurysmal occlusion was graded as good in all cases. When compared to DSA (18 cases), ceMRA had a sensitivity of 100% and specificity of 91% regarding aneurysm remnant detection. Assessability of the stent lumen varied and was limited in most cases.

CONCLUSIONS

Flow-diverter treatment achieves high occlusion rates and can cause major aneurysm shrinkage. CeMRA is highly valuable regarding imaging of the aneurysmal sac. There are limitations regarding the assessability of the stent lumen on ceMRA.

LEVEL OF EVIDENCE

Level 4, Case Series.

Pipeline for uncoilable or failed aneurysms: 3-year follow-up results

OBJECTIVE

The long-term effectiveness of endovascular treatment of large and giant wide-neck aneurysms using traditional endovascular techniques has been disappointing, with high recanalization and re-treatment rates. Flow diversion with the Pipeline Embolization Device (PED) has been recently used as a stand-alone therapy for complex aneurysms, showing significant improvement in effectiveness while demonstrating a similar safety profile to stent-supported coil treatment. However, relatively little is known about its long-term safety and effectiveness. Here the authors report on the 3-year safety and effectiveness of flow diversion with the PED in a prospective cohort of patients with large and giant internal carotid artery aneurysms enrolled in the Pipeline for Uncoilable or Failed Aneurysms (PUFS) trial.

METHODS

The PUFS trial is a prospective study of 107 patients with 109 aneurysms treated with the PED. Primary effectiveness and safety end points were demonstrated based on independently monitored 180-day clinical and angiographic data. Patients were enrolled in a long-term follow-up protocol including 1-, 3-, and 5-year clinical and imaging follow-up. In this paper, the authors report the midstudy (3-year) effectiveness and safety data.

RESULTS

At 3 years posttreatment, 74 subjects with 76 aneurysms underwent catheter angiography as required per protocol. Overall, complete angiographic aneurysm occlusion was observed in 71 of these 76 aneurysms (93.4% cure rate). Five aneurysms were re-treated, using either coils or additional PEDs, for failure to occlude, and 3 of these 5 were cured by the 3-year follow-up. Angiographic cure with one or two treatments of Pipeline embolization alone was therefore achieved in 92.1%. No recanalization of a previously completely occluded aneurysm was noted on the 3-year angiograms. There were 3 (2.6%) delayed device- or aneurysm-related serious adverse events, none of which led to permanent neurological sequelae. No major or minor late-onset hemorrhagic or ischemic cerebrovascular events or neurological deaths were observed in the 6-month through 3-year posttreatment period. Among 103 surviving patients, 85 underwent functional outcome assessment in which modified Rankin Scale scores of 0–1 were demonstrated in 80 subjects.

CONCLUSIONS

Pipeline embolization is safe and effective in the treatment of complex large and giant aneurysms of the intracranial internal carotid artery. Unlike more traditional endovascular treatments, flow diversion results in progressive vascular remodeling that leads to complete aneurysm obliteration over longer-term follow-up without delayed aneurysm recanalization and/or growth.

Clinical trial registration no.: NCT00777088 (clinicaltrials.gov)

Expanding the use of flow diverters beyond their initial indication: treatment of small unruptured aneurysms

Background

Experience with the endovascular treatment of unruptured small intracranial aneurysms by flow diverter devices is still limited.

Objective

To assess the safety and efficacy of the SILK flow diverter (SFD) in the treatment of small unruptured cerebral aneurysms (<10 mm).

Methods

We performed a retrospective review of a prospectively maintained database of patients treated with a SFD between July 2008 and December 2013 at 4 institutions in Spain to identify all patients with small unruptured aneurysms (<10 mm). Data for patient demographics, aneurysm characteristics, and technical procedures were analyzed. Angiographic and clinical findings were recorded during the procedure and at 6- and 12-month follow-ups.

Results

A total of 109 small aneurysms were treated with a SFD in 104 patients (78 women; 26 men; mean, median, and range of age: 55.2, 57.1, and 19–80 years, respectively). A total of 60 patients were asymptomatic (57.7%). All except 7 aneurysms (6.4%) arose from the anterior circulation. The mean size of the aneurysms was 4.7±1.9 mm. At 6 months, the neuromorbidity and neuromortality rates were 2.9% and 0.9%, respectively. Imaging at the 12-month follow-up showed complete occlusion, neck remnants, and residual aneurysm in 88.5% (69/78), 7.7% (6/78), and 3.3% (3/78) of cases, respectively. No delayed hemorrhage occurred.

Conclusions

The findings suggest that the indications for SFD can be safely extended to small intracranial aneurysms.

Postprocedural, midterm, and long-term results of cerebral aneurysms treated with flow-diverter devices: 7-year experience at a single center

OBJECTIVE

Flow diversion has emerged as a viable treatment option for selected intracranial aneurysms and recently has been gaining traction. The aim of this study was to evaluate the safety and effectiveness of flow-diverter devices (FDDs) over a long-term follow-up period.

METHODS

The authors retrospectively reviewed all cerebral aneurysm cases that had been admitted to the Division of Neurosurgery of the Università degli Studi di Napoli between November 2008 and November 2015 and treated with an FDD. The records of 60 patients (48 females and 12 males) harboring 69 cerebral aneurysms were analyzed. The study end points were angiographic evidence of complete aneurysm occlusion, recanalization rate, occlusion of the parent artery, and clinical and radiological evidence of brain ischemia. The occlusion rate was evaluated according to the O’Kelly-Marotta (OKM) Scale for flow diversion, based on the degree of filling (A, total filling; B, subtotal filling; C, entry remnant; D, no filling). Postprocedural, midterm, and long-term results were strictly analyzed.

RESULTS

Complete occlusion (OKM D) was achieved in 63 (91%) of 69 aneurysms, partial occlusion (OKM C) in 4 (6%), occlusion of the parent artery in 2 (3%). Intraprocedural technical complications occurred in 3 patients (5%). Postprocedural complications occurred in 6 patients (10%), without neurological deficits. At the 12-month follow-up, 3 patients (5%) experienced asymptomatic cerebral infarction. No further complications were observed at later follow-up evaluations (> 24 months). There were no reports of any delayed aneurysm rupture, subarachnoid or intraparenchymal hemorrhage, ischemic complications, or procedure- or device-related deaths.

CONCLUSIONS

Endovascular treatment with an FDD is a safe treatment for unruptured cerebral aneurysms, resulting in a high rate of occlusion. In the present study, the authors observed effective and stable aneurysm occlusion, even at the long-term follow-up. Data in this study also suggest that ischemic complications can occur at a later stage, particularly at 12–18 months. On the other hand, no other ischemic or hemorrhagic complications occurred beyond 24 months.

Complications associated with the use of flow-diverting devices for cerebral aneurysms: a systematic review and meta-analysis

OBJECTIVE

The objective of this study was to review the literature on the use of flow-diverting devices (FDDs) to treat intracranial aneurysms (IAs) and to investigate the safety and complications related to FDD treatment for IAs by performing a meta-analysis of published studies.

METHODS

A systematic electronic database search was conducted using the Springer, EBSCO, PubMed, Medline, and Cochrane databases on all accessible articles published up to January 2016, with no restriction on the publication year. Abstracts, full-text manuscripts, and the reference lists of retrieved articles were analyzed. Random-effects meta-analysis was used to pool the complication rates across studies.

RESULTS

Sixty studies were included, which involved retrospectively collected data on 3125 patients. The use of FDDs was associated with an overall complication rate of 17.0% (95% confidence interval [CI] 13.6%–20.5%) and a low mortality rate of 2.8% (95% CI 1.2%–4.4%). The neurological morbidity rate was 4.5% (95% CI 3.2%–5.8%). No significant difference in the complication or mortality rate was observed between 2 commonly used devices (the Pipeline embolization device and the Silk flow-diverter device). A significantly higher overall complication rate was found in the case of ruptured IAs than in unruptured IA (odds ratio 2.3, 95% CI 1.2–4.3).

CONCLUSIONS

The use of FDDs in the treatment of IAs yielded satisfactory results with regard to complications and the mortality rate. The risk of complications should be considered when deciding on treatment with FDDs. Further studies on the mechanism underlying the occurrence of adverse events are required.

Uterine fibroid therapy using interventional radiology mini-invasive treatments: current perspective

Uterine fibroids are common benign tumors of unclear etiopathology that affect the female reproductive tract. They are responsible for considerable morbidity and deterioration of life quality, and may have a negative impact on the reproductive system as well. Besides surgery aided by uterus-saving techniques, several minimally invasive procedures are now available within the field of interventional radiology that represent a valid solution for women who desire pregnancy and relief from disease-specific symptomatology. The main advantages offered by these techniques are low grade of invasiveness and short times of hospitalization. The most diffuse techniques are uterine artery embolization (UAE) and magnetic resonance-guided high-intensity focused ultrasound (MRgFUS). UAE is an endovascular procedure whose goal is obtained by provoking ischemia of the uterine vessels. MRgFUS is a thermoablation procedure that selectively ablates the symptomatic fibroids. In this review study, both procedures will be described, including a description of technical details, indications, contraindications, complications, and outcomes.

Minimally invasive treatments of painful bone lesions: state of the art

The role of the interventional radiology (IR) in the musculoskeletal system, and in particular in the bone, is a field of knowledge that is growing significantly in the last years with indications for treatment of both benign and malign lesions. In this paper, we review the state of the art of this application of the IR in the bone (bone metastasis and benign bone lesions) with discussion about all the techniques today used.

Long-Term Clinical and Angiographic Outcomes Following Pipeline Embolization Device Treatment of Complex Internal Carotid Artery Aneurysms: Five-Year Results of the Pipeline for Uncoilable or Failed Aneurysms Trial

BACKGROUND: Early and mid-term safety and efficacy of aneurysm treatment with the Pipeline Embolization Device (PED) has been well demonstrated in prior studies.

OBJECTIVE: To present 5-yr follow-up for patients treated in the Pipeline for Uncoilable or Failed Aneurysms clinical trial.

METHODS: In our prospective, multicenter trial, 109 complex internal carotid artery (ICA) aneurysms in 107 subjects were treated with the PED. Patients were followed per a standardized protocol at 180 d and 1, 3, and 5 yr. Aneurysm occlusion, in-stent stenosis, modified Rankin Scale scores, and complications were recorded.

RESULTS: The primary endpoint of complete aneurysm occlusion at 180 d (73.6%) was previously reported. Aneurysm occlusion for those patients with angiographic follow-up progressively increased over time to 86.8% (79/91), 93.4% (71/76), and 95.2% (60/63) at 1, 3, and 5 yr, respectively. Six aneurysms (5.7%) were retreated. New serious device-related events at 1, 3, and 5 yr were noted in 1% (1/96), 3.5% (3/85), and 0% (0/81) of subjects. There were 4 (3.7%) reported deaths in our trial. Seventy-eight (96.3%) of 81 patients with 5-yr clinical follow-up had modified Rankin Scale scores ≤2. No delayed neurological deaths or hemorrhagic or ischemic cerebrovascular events were reported beyond 6 mo. No recanalization of a previously occluded aneurysm was observed.

CONCLUSION: Our 5-yr findings demonstrate that PED is a safe and effective treatment for large and giant wide-necked aneurysms of the intracranial ICA, with high rates of complete occlusion and low rates of delayed adverse events.

Safety and efficacy of flow re-direction endoluminal device (FRED) in the treatment of cerebral aneurysms: a single center experience

BACKGROUND

Experience with the endovascular treatment of cerebral aneurysms by the Flow Re-Direction Endoluminal Device (FRED) is still limited. The aim of this study is to discuss the results and complications of this new flow diverter device (FDD).

METHODS

Between November 2013 and April 2015, 20 patients (15 female and five male) harboring 24 cerebral aneurysms were treated with FRED FDD in a single center.

RESULTS

Complete occlusion was obtained in 20/24 aneurysms (83 %) and partial occlusion in four (17 %). Intraprocedural technical complication occurred in one case (4 %) and post-procedural complications in three (12 %). None reported neurological deficits (mRS = 0). All FRED were patent at follow-up. No early or delayed aneurysm rupture, no subarachnoid (SAH) or intraparenchymal hemorrhage (IPH) no ischemic complications and no deaths occurred.

CONCLUSIONS

Endovascular treatment with FRED FDD is a safe treatment for unruptured cerebral aneurysms, resulting in a high rate of occlusion. The FRED is substantially equivalent to the other known FDDs, which show similar functions and technical profiles.

Efficacy and Safety of the Woven EndoBridge (WEB) Device for the Treatment of Intracranial Aneurysms: A Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE

Intrasaccular flow diverters are increasingly being used in the treatment of wide-neck and bifurcation aneurysms. We performed a systematic review and meta-analysis of existing literature on the Woven EndoBridge device in the treatment of intracranial aneurysms.

MATERIALS AND METHODS

A comprehensive literature search was performed through October 1, 2015. We extracted information on baseline aneurysm and patient characteristics. Outcomes studied included immediate and midterm (>3 month) angiographic outcomes (complete occlusion as well as adequate occlusion, defined as complete occlusion or neck remnant), aneurysm retreatment, intraoperative rupture, perioperative morbidity and mortality, thromboembolic complications, and treatment failure. Meta-analysis was performed by using the random-effects model.

RESULTS

Fifteen uncontrolled series were included in this analysis, including 565 patients with 588 aneurysms, of which 127 were ruptured. Initial complete and adequate occlusion rates were 27% (95% CI, 15%-39%) and 59% (95% CI, 39%-78%), respectively. Midterm complete and adequate occlusion rates after a median of 7 months were 39% (95% CI, 26%-52%) and 85% (95% CI, 78%-91%), respectively. Perioperative morbidity and mortality rates were 4% (95% CI, 1%-8%) and 1% (95% CI, 0%-2%), respectively. Midterm adequate occlusion rates for ruptured aneurysms were 85% (95% CI, 67%-98%), compared with 84% (95% CI, 72%-94%) for unruptured aneurysms (P = .89). Patients with ruptured aneurysm had similar rates of perioperative morbidity to patients with unruptured aneurysm (2%; 95% CI, 0%-26% versus 2%; 95% CI, 0%-6%, respectively; P = .35).

CONCLUSIONS

Early evidence derived from uncontrolled studies suggests that Woven EndoBridge treatment has a good safety profile and promising rates of adequate occlusion, especially given the complexity of aneurysms treated. Further prospective clinical trials are needed to confirm these results and better define the risks and benefits of use of the Woven EndoBridge device in treating wide-neck and wide-neck bifurcation aneurysms.

Mid-term and long-term follow-up of intracranial aneurysms treated by the p64 Flow Modulation Device: a multicenter experience

Background

Experience with the endovascular treatment of cerebral aneurysms using the p64 Flow Modulation Device is still limited. This study discusses the results and complications of this new flow diverter device.

Methods

40 patients (30 women, 10 men) with 50 cerebral aneurysms treated in six Italian neurointerventional centers with the p64 Flow Modulation Device between April 2013 and September 2015 were retrospectively reviewed.

Results

Complete occlusion was obtained in 44/50 aneurysms (88%) and partial occlusion in 3 (6%). In the other three aneurysms (6%), two cases of asymptomatic in-stent thrombosis and one intraprocedural occlusion of the parent vessel occurred. Technical complications were observed in eight procedures (16%). Permanent morbidity due to acute in-stent thrombosis and consequent ischemic stroke occurred in one patient (2.5%). No delayed aneurysm rupture, subarachnoid or intraparenchymal hemorrhage, or ischemic complications occurred and there were no deaths.

Conclusions

Endovascular treatment with the p64 Flow Modulation Device is a safe treatment for unruptured cerebral aneurysms, resulting in a high rate of occlusion. As with other flow diverter devices, we recommend this treatment mainly for large-necked aneurysms of the internal carotid artery siphon. However, endovascular treatment with the p64 device should also be encouraged in difficult cases such as aneurysms of the posterior circulation and beyond the circle of Willis.

Late recurrence of a completely occluded large intracranial aneurysm treated with a Tubridge flow diverter

We report a rare case of recurrence of a large intracavernous aneurysm after angiography proved complete occlusion. The aneurysm was treated by a combination of a Tubridge flow diverter and coils, and balloon angioplasty, after flow diverter devices deployment for parent vessel stenosis. Six month angiographic follow-up demonstrated complete occlusion. Unfortunately, obvious aneurysm recurrence was confirmed on 2 year angiographic follow-up. The probable mechanism of recurrence was analyzed.

Late recurrence of a completely occluded large intracranial aneurysm treated with a Tubridge flow diverter

We report a rare case of recurrence of a large intracavernous aneurysm after angiography proved complete occlusion. The aneurysm was treated by a combination of a Tubridge flow diverter and coils, and balloon angioplasty, after flow diverter devices deployment for parent vessel stenosis. Six month angiographic follow-up demonstrated complete occlusion. Unfortunately, obvious aneurysm recurrence was confirmed on 2 year angiographic follow-up. The probable mechanism of recurrence was analyzed.

Aneurysm Study of Pipeline in an Observational Registry (ASPIRe)

BACKGROUND AND OBJECTIVE

Few prospective studies exist evaluating the safety and efficacy of the Pipeline Embolization Device (PED) in the treatment of intracranial aneurysms. The Aneurysm Study of Pipeline In an observational Registry (ASPIRe) study prospectively analyzed rates of complete aneurysm occlusion and neurologic adverse events following PED treatment of intracranial aneurysms.

MATERIALS AND METHODS

We performed a multicenter study prospectively evaluating patients with unruptured intracranial aneurysms treated with PED. Primary outcomes included (1) spontaneous rupture of the Pipeline-treated aneurysm; (2) spontaneous nonaneurysmal intracranial hemorrhage (ICH); (3) acute ischemic stroke; (4) parent artery stenosis, and (5) permanent cranial neuropathy. Secondary endpoints were (1) treatment success and (2) morbidity and mortality at the 6-month follow-up. Vascular imaging was evaluated at an independent core laboratory.

RESULTS

One hundred and ninety-one patients with 207 treated aneurysms were included in this registry. The mean aneurysm size was 14.5 ± 6.9 mm, and the median imaging follow-up was 7.8 months. Twenty-four aneurysms (11.6%) were small, 162 (78.3%) were large and 21 (10.1%) were giant. The median clinical follow-up time was 6.2 months. The neurological morbidity rate was 6.8% (13/191), and the neurological mortality rate was 1.6% (3/191). The combined neurological morbidity/mortality rate was 6.8% (13/191). The most common adverse events were ischemic stroke (4.7%, 9/191) and spontaneous ICH (3.7%, 7/191). The complete occlusion rate at the last follow-up was 74.8% (77/103).

CONCLUSIONS

Our prospective postmarket study confirms that PED treatment of aneurysms in a heterogeneous patient population is safe with low rates of neurological morbidity and mortality. Patients with angiographic follow-up had complete occlusion rates of 75% at 8 months.

Intravenous C-Arm Conebeam CT Angiography following Long-Term Flow-Diverter Implantation: Technologic Evaluation and Preliminary Results

BACKGROUND AND PURPOSE

A noninvasive investigation with high spatial resolution and without metal artifacts is necessary for long-term imaging follow-up after flow-diverter implantation. We aimed to evaluate the diagnostic value of conebeam CT angiography with intravenous contrast enhancement in the assessment of vascular status following implantation of the Pipeline Embolization Device and to analyze the preliminary results of vascular status following long-term Pipeline Embolization Device implantation.

MATERIALS AND METHODS

This was an ongoing prospective study of consecutive patients with intracranial aneurysms treated with the Pipeline Embolization Device. Patients with a modified Rankin Scale score of 4-5 were excluded. The median and interquartile range of the time interval of Pipeline Embolization Device implantation to conebeam CT angiography with intravenous contrast enhancement were 56.6 and 42.9-62.4 months, respectively. Conebeam CT angiography with intravenous contrast enhancement was performed with the patient fully conscious, by using a C-arm CT with a flat panel detector.

RESULTS

There were 34 patients and 34 vascular segments. In all 34 cases, contrast effect and image quality were good and not substantially different from those of intra-arterial conebeam CTA. Metal artifacts occurred in all 14 cases with coil masses; the Pipeline Embolization Device was obscured in 3 cases. In all 34 cases, there was no residual aneurysm, no vascular occlusion, 1 vascular stenosis (50%), good Pipeline Embolization Device apposition to the vessel, and no Pipeline Embolization Device-induced calcification. All 28 Pipeline Embolization Device-covered side branches were patent.

CONCLUSIONS

Conebeam CT angiography with intravenous contrast enhancement is potentially promising and useful for effective evaluation of the vascular status following intracranial flow diverters. The Pipeline Embolization Device for intracranial aneurysms is probably safe and promising for long-term placement, with favorable morphologic outcome and without delayed complications.

Flow-diverter devices in the treatment of intracranial aneurysms: A meta-analysis and systematic review

OBJECTIVE

The purpose of this report was to discuss the overall limitations, safety and efficacy of flow-diverter stenting for intracranial aneurysms.

METHODS

The authors performed a meta-analysis from January 2009 to September 2014 using the terms "flow diverter" and "intracranial aneurysms." Additional studies were identified through references in each reviewed article. Data extraction, performed independently by the authors, included demographic data, technical and clinical complications, morbidity and mortality, aneurismal occlusion rates related to flow-diverter devices. The analysis was performed using a fixed effect.

RESULTS

Twenty-nine studies with 1524 patients and three to 62 months of follow-up were identified for analysis. The overall technical failure and complication rate was 9.3% (95% CI 6%-12.6%). The rate of procedure-related complication was 14% (95% CI 10.2%-17.9%) and 6.6% (95% CI 4%-9.1%) for morbidity and mortality. Fusiform, dissecting and circumferential aneurysm (OR 3.10, 95% CI 0.93-10.37) were significant risk factors for technical failure and complication. Posterior circulation location (OR 4.03, 95% CI 2.45-6.61), peripheral location (OR 2.74, 95% CI 1.52-4.94) and fusiform, dissecting and circumferential aneurysm (OR 1.95, 95% CI 1.15-3.30) were statistically significant risk factors for procedure-related complications. Posterior circulation location (OR 4.39, 95% CI 2.44-7.90) and peripheral location (OR 3.64, 95% CI 1.74-7.62) were statistically significant risk factors for morbidity and mortality.

CONCLUSIONS

Fusiform, dissecting and circumferential aneurysm, posterior circulation and peripheral locations have greater procedure-related complications.

Endovascular treatment of cerebral aneurysms using flow-diverter devices: A systematic review

BACKGROUND

Flow-diverter devices (FDDs) are new-generation stents placed in the parent artery at the level of the aneurysm neck to disrupt the intra-aneurysmal flow thus favoring intra-aneurysmal thrombosis.

OBJECTIVE

The objective of this review article is to define the indication and results of the treatment of intracranial aneurysms by FDD, reviewing 18 studies of endovascular treatment by FDDs for a total of 1704 aneurysms in 1483 patients.

METHODS

The medical literature on FDDs for intracranial aneurysms was reviewed from 2009 to December 2014. The keywords used were: "intracranial aneurysms," "brain aneurysms," "flow diverter," "pipeline embolization device," "silk flow diverter," "surpass flow diverter" and "FRED flow diverter."

RESULTS

The use of these stents is advisable mainly for unruptured aneurysms, particularly those located at the internal carotid artery or vertebral and basilar arteries, for fusiform and dissecting aneurysms and for saccular aneurysms with large necks and low dome-to-neck ratio. The rate of aneurysm occlusion progressively increases during follow-up (81.5% overall rate in this review). The non-negligible rate of ischemic (mean 4.1%) and hemorrhagic (mean 2.9%) complications, the neurological morbidity (mean 3.5%) and the reported mortality (mean 3.4%) are the main limits of this technique.

CONCLUSION

Treatment with FDDs is a feasible and effective technique for unruptured aneurysms with complex anatomy (fusiform, dissecting, large neck, bifurcation with side branches) where coiling and clipping are difficult or impossible. Patient selection is very important to avoid complications and reduce the risk of morbidity and mortality. Further studies with longer follow-up are necessary to define the rate of complete occlusion.

p64 Flow Modulation Device in the treatment of intracranial aneurysms: initial experience and technical aspects

BACKGROUND

Experience with the endovascular treatment of cerebral aneurysms by flow diverter devices (FDDs) is limited to four devices (Pipeline, Covidien; FRED, Microvention; Silk, Balt Extrusion; Surpass, Stryker), as reported in different studies.

OBJECTIVE

To describe the initial experience and the technical innovations of a new-generation FDD (p64 Flow Modulation Device, Phenox, Bochum, Germany).

METHODS

Between December 2014 and February 2015, six intracranial aneurysms in five patients (four women, one man; mean age 63 years) were treated with the p64 Flow Modulation Device.

RESULTS

Immediate post-treatment angiography showed reduced flow into all aneurysms. No long-term angiographic data are available. The device may be easily deployed and totally retrieved with a unique mechanical detachment. No periprocedural technical complications occurred. No early or delayed aneurysm rupture, no ischemic or hemorrhagic complications, and no neurological morbidity or death were seen.

CONCLUSIONS

Treatment of cerebral aneurysms with the p64 Flow Modulation Device is a safe procedure with no technical complications. The mechanical detachment and the 100% retrievability are significant advantages of this new device. However, large prospective studies with long-term clinical and angiographic follow-up are necessary to assess the role of the p64 in the endovascular treatment of intracranial aneurysms.

Flow diverter device for the treatment of small middle cerebral artery aneurysms

PURPOSE

Experience with the endovascular treatment of middle cerebral artery (MCA) aneurysms by flow diverter devices (FDD) is still limited. This study examines the results and complications of FDD for small aneurysms at this location.

METHODS

From February 2010 to December 2013, 14 patients (10 women; mean age 59 years) with 15 small MCA aneurysms were treated with FDD. All procedures were performed with the Pipeline embolization device (PED).

RESULTS

Complete occlusion was obtained in 12/15 aneurysms (80%) and partial occlusion in 3 (20%). Among 13 aneurysms with a side branch, this was patent at the angiographic control in 4 cases, showed decreased filling in 6, and was occluded in 3 (with neurological deficits in 2). All PEDs were patent at follow-up. Post-procedural ischemic complications occurred in 4 (27%) procedures with permanent neurological deficit (modified Rankin score 2) in 3 (21%). No early or delayed aneurysm rupture, no subarachnoid or intraparenchymal hemorrhage and no deaths occurred.

CONCLUSIONS

Endovascular treatment with FDD is a relatively safe treatment for small MCA aneurysms resulting in a high occlusion rate. The findings of this study suggest that complete occlusion after endovascular treatment with FDD can be delayed (>6 months). Ischemic complications may occur as early or delayed, particularly at clopidogrel interruption.