Safety, efficacy, and short-term follow-up of the use of Pipeline™ Embolization Device in small (<2.5mm) cerebral vessels for aneurysm treatment: single institution experience

Hyperhomocysteinemia increases the risk of vertebrobasilar dissecting aneurysm among the male Han Chinese population: a retrospective case-control study

OBJECT

Vertebrobasilar dissecting aneurysms (VBDAs) are known to have a poor natural history with high rates of re-bleeding and mortality. There is a strong relation between hyperhomocysteinemia (HHcy) and cerebrovascular disease; we perform a retrospective study within the male of Chinese Han population to explore the association between HHcy and VBDAs.

METHODS

Eighty-eight male patients with VBDA and Eighty-one male control subjects were evaluated for their serum total homocysteine levels. With multiple logistic regression analysis, the association between HHcy and the risk of VBDAs was estimated. Interaction and stratified analyses were conducted according to age, BMI, smoking status, drinking status, and chronic disease histories. The two-piecewise linear regression model examined the threshold effect.

RESULTS

The multivariate logistic regression analyses revealed a significant association between HHcy and VBDAs (odds ratio (OR) = 2.62; 95% confidence interval (CI), 1.02-6.71) after adjusting for classical vascular risk factors. The relationship was stable in all subgroup analysis. The interactive role was not found in the association between HHcy and VBDAs for the potential risk factor.

CONCLUSIONS

In summary, our study provides evidence that HHcy can increases the risk of VBDAs in the male Han Chinese population. Further researches with appropriate study designs including sex differences and aneurysm types are needed to verify this association.

Pipeline versus non-pipeline flow diverter treatment for M1 aneurysms: A systematic review and meta-analysis

BACKGROUND

The flow diversion treatment of aneurysms located distal to the Circle of Willis has recently increased in frequency. We conducted a systematic review and meta-analysis of the clinical and radiological outcomes of flow diverter (FD) embolization in treating M1 aneurysms.

METHODS

PubMed, Web of Science, Ovid Medline, Ovid Embase, and Scopus were searched up to May 2024 using the Nested Knowledge platform. We included studies assessing the long-term clinical and radiological outcomes for M1 aneurysms. Results of FDs classified as Pipeline Embolization Devices (PED) versus other types of FDs. Angiographic occlusion rates, ischemic and hemorrhagic complications, and favorable clinic outcomes were included. All data were analyzed using R software version 4.2.2.

RESULTS

Thirteen studies with 112 total patients (58 patients for PED and 54 patients for other FD devices) were included in our meta-analysis. The overall adequate (complete + near-complete) occlusion rates were 85.1%. The complete occlusion rate was higher with PED than with other FD devices (72.9% PED and 41.6% for non-PED FDs, respectively, p-value <.01). The ischemic complications were 9.9% and 9.0% for the PED and non-PED groups, respectively (p-value = .89). The overall modified Rankin Scale 0-2 was 100% for the non-PED and 97.1% for the PED group (p-value = .51). In-stent stenosis rate was 7.5% for PED devices compared to 2.6% in the non-PED group (p-value = .35).

CONCLUSIONS

This relatively small meta-analysis showed high rates of adequate and complete occlusion in FD treatment of M1 segment aneurysms, with favorable safety profiles. PEDs were associated with higher rates of complete aneurysm occlusion compared to other types of FDs.

Endovascular treatment of distal anterior cerebral artery aneurysms using flow modulation devices: mid- and long-term results from a two-center study

Purpose

Flow-diverter (FD) stents have become an established treatment for intracranial aneurysms in recent years, but their use for aneurysms in distal cerebral vessels with small carrier vessel diameters remains controversial. This study describes the method and mid- and long-term outcomes of FD treatment of distal anterior cerebral artery aneurysms (DACAAs) at two neurointerventional centers, to elucidate this topic and provide more in-depth data.

Methods

Data for all patients at two neurointerventional centers who were treated with FDs for DACAAs in the pericallosal and supracallosal segment of the anterior cerebral artery were retrospectively analyzed. Data on periprocedural complications, and short-, mid- and long-term follow-up findings were recorded.

Results

Forty-one patients were eligible for inclusion in the study. Three FD models were used, one of which had an anti-thrombotic coating. Two periprocedural complications (5%) occurred but did not cause a change in the mRS. In the long-term follow-up, at 29 months and beyond, 83% of assessable patients showed complete occlusion of the aneurysms without new neurological deficits.

Conclusion

FDs are a safe and effective treatment approach for DACAAs. This study indicated a low risk of complications, and high closure rates in short-, mid- and long-term follow-up.

Flow Diversion for Treatment of Anterior Inferior Cerebellar Artery Aneurysms: Mechanism and Pitfalls from a Novel Management Strategy

BACKGROUND

Anterior inferior cerebellar artery (AICA) aneurysms present a challenge for neurosurgeons and neurointerventionalists alike.

METHODS

Cases of AICA aneurysms managed with endovascular flow diversion at our institute are reviewed with their angiographic outcomes.

RESULTS

Both direct and indirect flow diversion provide complete aneurysm occlusion at follow-up. We propose a stratified method of approaching AICA aneurysms based on location, rupture status, and neck size.

CONCLUSIONS

Careful evaluation of preoperative parameters is paramount in deciding between a surgical or a neuroendovascular approach. Low-profile stents in the future may assist in direct flow diversion of AICA trunk aneurysms. In addition, neurosurgeons need to be well versed in endovascular approaches.

Treatment Outcomes of 94 Cases of Pipeline Embolization Device in a Single Center: Predictive Factors of Incomplete Aneurysm Occlusion

Objective

This study aimed to report the outcome of an endovascular treatment with a pipeline embolization device (PED) at a single center. We also examined the predictive factors for an incomplete occlusion after the PED placement.

Methods

The subjects were 94 patients with 109 aneurysms who underwent the PED placement at our single center from June 2015 to September 2022. As treatment outcomes, we investigated the PED placement success rate, perioperative morbidity and mortality, postoperative cranial nerve improvement rate, and the classification of angiographic result at 6 months after the PED placement. Furthermore, the predictors of an incomplete occlusion were investigated in detail.

Results

One hundred nine aneurysms locations were: C1 (9), C2 (30), C3 (15), C4 (53), and C5 (2) in the internal carotid artery segments. Perioperative morbidity, including the asymptomatic ones, occurred in 10 cases (10.6%). Among these 10 cases, the modified Rankin Scale (mRS) improved to preoperative mRS after 90 days in 9 cases except 1 case. On the other hand, no perioperative mortality was observed. The postoperative cranial nerve improvement rate was 84.4%, and 61.7% of patients had a complete occlusion in the follow-up angiography, 6 months after the PED placement. Predictive factors for an incomplete occlusion after the PED placement were the elderly aged 70 years or older (P-value = 0.0214), the elderly aged 75 years or older (P-value = 0.0009), and the use of anticoagulants (P-value = 0.0388) in an univariate analysis. Further, the multivariate analysis revealed that the elderly aged 75 years or older was a predictive factor of an incomplete occlusion in this study.

Conclusion

We summarized the outcomes of the PED treatment at our single center. In this study, the elderly aged 75 years or older was a predictive factor of an incomplete occlusion after the PED placement.

Emergent carotid stenting versus no stenting for acute ischemic stroke due to tandem occlusion: a meta-analysis

BACKGROUND

Emergent carotid artery stenting (eCAS) is performed during mechanical thrombectomy for acute ischemic stroke due to tandem occlusion. However, the optimal management strategy in this setting is still unclear.

OBJECTIVE

To carry out a systematic review and meta-analysis to investigate the safety and efficacy of eCAS in patients with tandem occlusion.

METHODS

Systematic review followed the PRISMA guidelines. Medline, EMBASE, and Scopus were searched from January 1, 2004 to March 7, 2022 for studies evaluating eCAS and no-stenting approach in patients with stroke with tandem occlusion. Primary endpoint was the 90-day modified Rankin Scale score 0-2; secondary outcomes were (1) symptomatic intracerebral hemorrhage (sICH), (2) recurrent stroke, (3) successful recanalization (Thrombolysis in Cerebral Infarction score 2b-3), (4) embolization in new territories, and (5) restenosis rate. Meta-analysis was performed using the Mantel-Haenszel method and random-effects modeling.

RESULTS

Forty-six studies reached synthesis. eCAS was associated with higher good functional outcome compared with the no-stenting approach (OR=1.52, 95% CI 1.19 to 1.95), despite a significantly increased risk of sICH (OR=1.97, 95% CI 1.23 to 3.15), and higher successful recanalization rate (OR=1.91, 95% CI 1.29 to 2.85). Restenosis rate was lower in the eCAS group than in the no-stenting group (2% vs 9%, p=0.001). Recanalization rate was higher in retrograde than antegrade eCAS (OR=0.51, 95% CI 0.28 to 0.93). Intraprocedural antiplatelets during eCAS were associated with higher rate of good functional outcome (60% vs 46%, p=0.016) and lower rate of sICH (7% vs 11%; p=0.08) compared with glycoprotein IIb/IIIa inhibitors.

CONCLUSIONS

In observational studies, eCAS seems to be associated with higher good functional outcome than no-stenting in patients with acute ischemic stroke due to tandem occlusion, despite the higher risk of sICH. Dedicated trials are needed to confirm these results.

Flow Diverting Stents in Cerebral Small Caliber Vessels (< 2 mm) for Aneurysm Treatment : A Three Center Retrospective Study

PURPOSE

The off-label use of flow diverting stents (FDS) for treating cerebral aneurysms in small distal vessels is increasing in clinical practice with encouraging results; however, data directly addressing the parent vessel size are still scarce. Our aim was to evaluate the safety and efficacy of FDS placement in anterior and posterior circulation aneurysms with parent arteries ≤ 2 mm in a real-world representative setting.

METHODS

We retrospectively reviewed patients treated with FDS at the three participating university hospitals between 2009 and 2021. The inclusion criteria were the placement of at least one FDS in a parent vessel with a maximum diameter of 2 mm or less. The primary clinical safety endpoint was the absence of death, major or minor symptomatic stroke, transient ischemic attack and procedure-related intracranial hemorrhage. Clinical outcome was assessed using the modified Rankin Scale (mRS) score at the follow-up visit at 1 year. The primary efficacy endpoint was defined as complete and near-complete occlusion at the 1‑year follow-up.

RESULTS

We identified 55 patients harboring 56 aneurysms. The primary clinical safety endpoint was obtained in 93% of cases. The hemorrhagic and thromboembolic complication rates were 4% and 9%, respectively. No patient died or had a relevant discrepancy (> 1 point) at the pre-mRS and post-mRS. The primary efficacy endpoint was reached in 80% of cases.

CONCLUSION

The use of FDS in vessels < 2 mm is technically feasible with good aneurysm occlusion rates and an acceptable safety profile. Nevertheless, it is essential to be aware of the of the main complications associated when operating in small diameter vessels.

Initial and mid-term results of LEO Baby stent-assisted coiling of intracranial aneurysms located in small arteries: A single-center experience with 131 consecutive patients

Background and purpose

Low-profile intracranial stents such as the LEO Baby stents are considered to be advantageous for the treatment of intracranial aneurysms originating from small arteries. This study aimed to evaluate the initial and mid-term clinical and angiographic results of LEO Baby stents in stent-assisted coiling of intracranial aneurysms with small parent arteries (<2.5 mm).

Methods

We performed a retrospective study to identify 131 patients with aneurysms arising from small parent arteries treated with Leo Baby stent-assisted coiling in a single institution between October 2018 and June 2021. We assessed the immediate and progressive aneurysm occlusion rates, procedure-related complications, and clinical outcomes.

Results

A total of 131 patients with 135 aneurysms were identified, including 65 (48.1%) cases of acutely ruptured aneurysms. Technical success was achieved in all cases (100%). The immediate angiography showed complete occlusion in 111 aneurysms (82.2%), neck remnants in 19 (14.1%), and residual sac in 5 (3.7%). Procedure-related complications occurred in 14 cases (10.3%), including 13 (9.6%) thromboembolic complications and 1 (0.7%) hemorrhagic complication. Six-month follow-up angiography was achieved in 106 (78.5%) aneurysms, which showed complete occlusion in 102 (96.2%) aneurysms, neck remnants in 2 (1.9%), and residual sac in 2 (1.9%). Clinical follow-up was available in all patients with a median duration of 6.8 months, and favorable clinical outcomes (modified Rankin Scale score: 0–2) reached 91.6%. The mortality rate was 4.6%.

Conclusion

Our results demonstrate that stent-assisted coiling of intracranial aneurysms located on small arteries using LEO Baby stents is technically feasible, highly effective, and has midterm durability in aneurysmal occlusion.

Microsurgical clipping versus newer endovascular techniques in treatment of unruptured anterior communicating artery-complex aneurysms: a meta-analysis and systematic review

The aim of this study is to compare occlusion rate, complication rate, and clinical outcome of microsurgical clipping (MC) and advanced endovascular techniques (EVT) in unruptured anterior communicating artery-complex aneurysms (ACoCAs). We reviewed the scientific literature reporting occlusion rate, time of occlusion assessment, and clinical outcome of MC and EVT in patients with unruptured ACoCAs, from January 2009 to December 2019. We included in our analysis 25 studies and 872 patients with unruptured ACoCAs (434 treated with endovascular techniques and 438 with MC). Ninety-three (10.7%), 320 (36.7%), 21 (2.4%), and 438 (50.2%) were treated with flow diverter (FD), stent-assisted coiling (SAC), endosaccular devices (ES), and microsurgical clipping (MC) respectively. FD, SAC, ES, and MC subgroups presented minor complications in 11.8%, 3.8%, 14.3%, and 7.1% of cases (p=.016), and major complications in 3.2%, 4.4%, 0%, and 7.1% (p=.136) of patients. A total occlusion rate post-treatment has been achieved in 4.3%, 87.1%, 47.6%, and 98.2% of cases (p=.000), while at 12 months' follow-up in 50%, 66%, 83.3%, and 80% of patients (p=.001). FD, SAC, ES, and MC subgroups had a good clinical outcome at 12 months in 93.5%, 90.5%, 100%, and 67.8% of cases. MC is associated with higher post-treatment total occlusion rate, but higher complication and lower good clinical outcome rates. EVT are promising in treating unruptured anterior cerebral artery aneurysms with high margin of safety and good clinical outcome, despite the lower total occlusion rate.

Flow diversion for aneurysms beyond the circle of Willis: A preliminary experience

OBJECTIVE

To evaluate the safety and efficacy of flow diversion (FDs) for the aneurysms beyond the circle of Willis.

METHODS AND MATERIALS

We retrospectively reviewed the prospectively maintained database in our center and enrolled patients with aneurysms beyond the circle of Willis (defined as at or distal to the M1, A2, and P2 segments) that were treated with FDs.

RESULTS

Between July 2017 to December 2020, 28 patients with 28 aneurysms met the inclusion criteria and were included in this study, with a median age of 50 years old (IQR, 36-63 years). Thirty FDs, including 5 Pipelines and 25 Tubridge FDs, were deployed. Perioperative complications were noticed in 2 patients (7.1%), while asymptomatic adverse events occurred in another three patients (10.7%). Delayed complications occurred in 3.6% of patients (1/28). All patients received clinical follow-up, with the mortality and long-term morbidity of 0 and 3.6% (1/28), respectively. Angiographic follow-up data were available for 26 patients (92.9%) with an interval of 10 ± 7 months (ranged 2-26 months). Sixteen patients (61.5%) showed complete or nearly complete occlusion of aneurysms (OKM grading scale D and C); 6 cases (23.1%) were revealed incomplete occlusion (OKM grading scale B), and 4 cases (15.4%) remained unchanged (OKM grading scale A). The existence of the perforators derived from aneurysms was associated with a lower occlusion rate (p = 0.032).

CONCLUSION

Flow diversion is reliable in the treatment of distal aneurysms with a high technical success rate and low permanent disability rate. The presence of side branches derived from aneurysms was associated with a lower aneurysm occlusion rate.

Pipeline embolization of distal posterior inferior cerebellar artery aneurysms

BACKGROUND AND PURPOSE

Flow diversion is commonly used to treat intracranial aneurysms in various regions of the cerebral vasculature, but is only approved for use in the internal carotid arteries. Treatment of distal PICA aneurysms with PED is sometimes performed but has not been well studied. Here, we report our experience with flow diversion of distal PICA aneurysms with PED.

MATERIALS AND METHODS

Clinical and angiographic data of eligible patients was retrospectively obtained and assessed for key demographic characteristics and clinical and angiographic outcomes. Principal outcomes included rates of aneurysm occlusion, ischemic or hemorrhagic complication, technical complication, and in-stent stenosis.

RESULTS

Three female and 2 male patients underwent placement of PED in the PICA for treatment of 5 distal PICA aneurysms. Clinical and angiographic follow-up was obtained for all patients. Complete aneurysm occlusion was observed in 100% (5/5) of treated aneurysms at 6 month and longest angiographic follow-up. While there were no ischemic or device-related complications, delayed hemorrhagic complications occurred in 20% (1/5) of patients.

CONCLUSION

Pipeline embolization of distal PICA aneurysms can be performed in select patients. Further study is necessary in larger cohorts to better define clinical scenarios in which flow diversion in the distal PICA should be considered.

Endovascular Management of Distal Anterior Cerebral Artery Aneurysms: A Multicenter Retrospective Review

INTRODUCTION

Distal anterior cerebral artery aneurysms (DACAA) are a rare and difficult entity to manage. Endovascular treatment has evolved for safe and durable treatment of these lesions. The objective of this study is to report the safety, efficacy, and outcomes of endovascular treatment of DACAA.

METHODS

A retrospective review of DACAA endovascularly treated at 5 different institutions was performed. Data included demographics, rupture status, radiographic features, endovascular technique, complication rates, and long-term angiographic and clinical outcomes. A primary endpoint was a good clinical outcome (modified Rankin scale 0-2). Secondary endpoints included complications and radiographic occlusion at follow-up.

RESULTS

A total of 84 patients were reviewed. The mean age was 56, and 64 (71.4%) were female. Fifty-two (61.9%) aneurysms were ruptured. A good functional outcome was achieved in 59 patients (85.5%). Sixty (71.4%) aneurysms were treated with primary coiling, and the remaining 24 were treated with flow diversion. Adequate occlusion was achieved in 41 (95.3%) aneurysms treated with coiling, and 17 (89.5%) with flow diversion. There were total 11 (13%) complications. In the flow diversion category, there were 2, both related to femoral access. In the coiling category, there were 9: 5 thromboembolic, 3 ruptures, and 1 related to femoral access.

CONCLUSION

Endovascular treatment, and in particular, flow diversion for DACAA, is safe, feasible, and associated with good long-term angiographic and clinical outcomes.

Early clinical experience with the p48MW HPC and p64MW HPC flow diverters in the anterior circulation aneurysm using single anti-platelet treatment

Background

The p64MW HPC and p48MW HPC flow diverters have reduced thrombogenicity due to hydrophilic coating. The purpose of this study was to evaluate its safety and efficacy in Mongolian patients under single antiplatelet therapy (SAPT) with prasugrel.

Materials and methods

We performed a retrospective review of patients enrolled into our prospectively maintained database to identify all patients treated with either the p48MW HPC or p64MW HPC under SAPT. We recorded baseline demographics, aneurysm size and location, procedural complications, angiographic and clinical results.

Results

24 patients, (female = 21, 87.5%), age 48.2 ± 11.6 years (range 25–63) underwent treatment of 30 aneurysms with either p64MW HPC or p48MW HPC. All aneurysms were saccular with dome width 8.2 ± 6.5 (range 1.6–26.0 mm) and dome height 7.6 ± 6.7 (range 1.6–30.0 mm). None of the aneurysms were previously treated. The average PRU was 54.6 ± 31.2 (range 1–127) on pre-operative VerifyNow testing. Angiographic follow-up was available for 13 patients (17 aneurysms), 183 ± 36 days post-procedure, at which point 64.7% of aneurysms (n = 11/17) were completely occluded and 11.8% (n = 2/17) had only neck remnants resulting in 76.5% of aneurysms being adequately occluded A single intra-operative complication (4.2%) occurred however all patients were mRS ≤1 at last follow-up. There were two post-operative complications neither of which resulted in permanent neurological morbidity. There were no instances of post-operative aneurysmal rupture or delayed parenchymal haemorrhage. The overall mortality was 0%.

Conclusion

The efficacy and safety of p64MW HPC coated devices under SAPT is similar to uncoated flow diverters that require DAPT.

Correlation Between Vascular Geometry Changes and Long-Term Outcomes After Enterprise Stent Deployment for Intracranial Aneurysms Located on Small Arteries

BACKGROUND

Enterprise stents are widely used for intracranial aneurysms located on small arteries (<2.5 mm in diameter) and change the geometry of parent arteries. The purpose of this study was to investigate the correlation between vascular geometry changes and long-term outcomes.

METHODS

Between May 2013 and 2018, 1065 consecutive intracranial aneurysms were treated with Enterprise stents at our institution. After inclusion and exclusion criteria were applied, 377 aneurysms with >6 months of digital subtraction angiography follow-up were evaluated. The cohort comprised 101 aneurysms located on small parent arteries. After stent-assisted coiling, the vascular geometry parameters of small parent arteries were compared to explore their correlation with procedural complications, delayed stent migration, and recanalization.

RESULTS

The rate of delayed aneurysm occlusion in patients with initial efferent artery diameter (De) <2.5 mm was significantly higher than in patients with De >2.5 mm (62.2% vs. 40.2%; P = 0.032). At follow-up, vascular geometry parameters significantly increased (P < 0.001). In multivariate analyses, larger aneurysms and initial parent artery angle (α) <90° were independent predictors of procedural complications and discrepancy in vessel size (ΔD) >0.5 mm was an independent predictor of delayed stent migration. Larger aneurysms and follow-up angle change (ΔAngle) <30° were independent predictors for recanalization of aneurysms located on small arteries.

CONCLUSIONS

Enterprise stent-assisted coiling of intracranial aneurysms located on small arteries is safe and effective. Our study found that Enterprise deployment in small arteries had a low procedural complication rate and high stent tolerance. Vascular geometry changes play an important role in aneurysm recanalization.

The Silk Vista Baby - The UK experience

BACKGROUND

The Silk Vista Baby (SVB) flow diverter (FDS) is the only FDS deliverable via a 0.017 inch microcatheter and is specifically designed for the distal vasculature. We sought to evaluate the safety and efficacy of the SVB.

MATERIALS AND METHODS

We performed a retrospective review to identify SVB cases at 4 tertiary neurosurgical centres within the U.K. Clinical, procedural, angiographic and follow-up data were collected.

RESULTS

We identified 60 patients (35 female, 58%) of average age 54 ± 10.5 (range 30-72) with 61 aneurysms, 50 (81.9%) located in the anterior circulation. The majority of the aneurysms treated were unruptured (46, 75.4%) and saccular (46, 75.4%). Dome size was 6.2 ± 6.2 mm (range 1-36mm) and parent vessel diameter was 2.3 ± 0.4 mm (range 1.2-3.3 mm).An average number of 1.07 devices were implanted. Coils or other devices were implanted in 14 aneurysms (23.3%). At last angiographic follow-up (n = 55), 7.5 ± 4.2 months post-procedure, 32 aneurysms (57.1%) were graded as RRC I, 7 (12.5%) RRC II, and 17 RRC III (30.4%).Clinical complications, excluding death, were seen in 4 patients (6.8%) including 1 delayed aneurysm rupture and 3 symptomatic ischaemic events. Only one patient had permanent morbidity (mRS 1). 3 patients died during follow-up (5.1%); 2 deaths were related to the aneurysms (3.4%) - one ruptured dissecting MCA aneurysm, and one giant partially thrombosed posterior circulation aneurysm. 93% of patients were mRS ≤ 2 at last follow-up.

CONCLUSION

The SVB has high rates of technical success and an acceptable safety profile. Distal aneurysms may occlude slower due to relative oversizing of the devices.

Expanding Indications for Flow Diverters: Distal Aneurysms, Bifurcation Aneurysms, Small Aneurysms, Previously Coiled Aneurysms and Clipped Aneurysms, and Carotid Cavernous Fistulas

Flow diverter devices have gained wide acceptance for the treatment of unruptured intracranial aneurysms. Most studies are based on the treatment of large aneurysms harboring on the carotid syphon. However, during the last years the “off-label” use of these stents has widely grown up even if not supported by randomized studies. This review examines the relevant literature concerning “off-label” indications for flow diverter devices, such as for distal aneurysms, bifurcation aneurysms, small aneurysms, recurrent aneurysms, and direct carotid cavernous fistulas.

The p48 MW flow modulation device for treatment of unruptured, saccular intracranial aneurysms: a single center experience from 77 consecutive aneurysms

Background

The p48 MW Flow Modulation Device (phenox, Bochum Germany) is a low profile flow diverter stent (FDS), designed for implantation into intracranial arteries with a diameter of less than 3.5 mm.

Objective

To evaluate the safety and efficacy of the p48 MW FDS in the treatment of unruptured aneurysms located at intracranial arteries with less than 3.5 mm diameter based on a retrospective analysis from a single tertiary neurovascular center.

Methods

A prospectively maintained database was retrospectively reviewed to identify all cases of intracranial saccular aneurysms treated electively with the p48 MW device. Records were made of basic demographics, aneurysmal characteristics, interventional procedures, adverse events, clinical outcomes and occlusion rates on angiographic follow-ups.

Results

A total of 77 aneurysms and 74 patients were included. The mean size of the treated aneurysms was 3.5 ± 2.4 mm and the mean aspect ratio was 1.3 ± 0.4. A total of 80 endovascular procedures were performed with a total of 12 (15%) adverse events leading to two (2.5%) permanent morbidities/mortalities. Technical issues were encountered in 3 (3.9%) cases. Adequate occlusion of the treated aneurysm was recorded in 55.6% and 63.9% on the first and latest available DSA follow-ups, respectively. There were no cases of side-branch occlusion.

Conclusions

The p48 MW is an easy-to-use implant with very good safety margins. Side branch occlusion and significant in-stent stenosis are infrequently encountered. The time from implantation to sufficient aneurysm occlusion takes longer than with FDS with lower porosity.

Coiling for an unruptured saccular aneurysm at the non-branching segment of the distal anterior cerebral artery: Case report and literature review

BACKGROUND

Saccular aneurysms in the non-branching segment of the distal anterior cerebral artery (DACA) are extremely rare. Here, we describe the first case of coil embolization using a simple, non-adjunctive technique for an aneurysm at this rare location.

CASE DESCRIPTION

A 74-year-old man with an asymptomatic, unruptured aneurysm of the right DACA was followed up annually for 3 years by medical checkup. Endovascular treatment was proposed because of a slight angiographic change in the shape of the aneurysm in the past year. The aneurysm at the non-branching site of the right calloso-marginal artery was 2 mm distal to the origin, and measured 3 mm in height and 3.3 mm in width, with a neck measuring 1.7 mm wide; the calloso-marginal artery diameter was 1.6 mm. The aneurysm was successfully embolized with a simple technique using a Pre-Shaped S Microcatheter and two coils.

CONCLUSIONS

The simple, non-adjunctive technique for coil embolization of saccular side-wall type aneurysm in the non-branching segment of the DACA could be performed using the appropriate catheter and a softer coil.

Future Directions of Flow Diverter Therapy

The treatment of intracranial aneurysms has undergone a few very significant paradigm shifts in its history. Needless to say, microsurgery and surgical clipping served as the initial basis for successful treatment of these lesions. The pursuit of endovascular therapy subsequently arose from the desire to reduce the invasiveness of therapy. While the first breakthrough arose with Guido Guglielmi's invention of the detachable platinum coil, commercialized flow diverter therapy represents a disruptive therapy with a completely different paradigm for aneurysmal obliteration. This has not only altered the distribution of aneurysmal management strategies, but also opened the gateway to the treatment of previously inoperable lesions. With the basic flow diverter stent technology now considered an integral part of the neurointerventional armamentarium, we now consider what may lay in the future - including potential directions for research with regards to case selection; the location and type of aneurysms which may become routinely treatable; and modifications to the flow diverter, which may increase its utility and safety in terms of size, structural design, and surface modifications.

Introduction: History and Development of Flow Diverter Technology and Evolution

The introduction of flow diverter technology to the field of neurointervention has revolutionized the treatment of intracranial aneurysms. The therapy approach has shifted from intrasaccular aneurysm treatment to exclusion of the aneurysm from the blood circulation with remodeling of the parent artery. Previously, “difficult”-to-treat aneurysms including fusiform and blister aneurysms, but also aneurysms arising from a diseased vessel segment, can now be safely and permanently treated with flow diverters.

 A little over a decade ago, after extensive bench testing and refinement of the flow diverter concept, the device was eventually available for clinical use and today it has become a standard treatment for intracranial aneurysms. Currently, United States Food and Drug Administration (FDA)-approved flow diverters are the Pipeline Embolization Device (Medtronic) and the Surpass Streamline Flow Diverter (Stryker).

 The devices can either be delivered or deployed via a standard femoral artery approach or a radial artery approach. Other considerations for catheter setup and device deployment strategies depending on aneurysm location or vessel anatomy are described.

Pipeline Embolization Device for Pericallosal Artery Aneurysms: A Retrospective Single Center Safety and Efficacy Study

BACKGROUND

Pericallosal artery aneurysm treatment may be challenging using traditional endovascular techniques.

OBJECTIVE

To demonstrate the feasibility, efficacy, and safety of endovascular treatment of pericallosal artery aneurysm using flow diverters.

METHODS

We performed a retrospective review of our institutional database from July 2013 through July 2016 and identified 7 subjects with a pericallosal artery aneurysm treated with the Pipeline embolization device (ev3 Neurovascular, Medtronic, Dublin, Ireland) and at least 1 follow-up angiogram. Technical feasibility, procedural complication, angiographic results, and clinical outcome were evaluated.

RESULTS

Placement of the Pipeline embolization device was successful in all cases without evidence of procedural complication. Five out of 7 subjects showed a complete aneurysm occlusion at 6- to 12-mo follow-up angiogram. The 2 subjects with persistent aneurysm filling showed decreased aneurysm sac volume on follow-up angiograms (96% and 60%). There was no evidence of in-implant stenosis or intimal hyperplasia. No thromboembolic or hemorrhagic complications were seen during the follow-up period. Only 1 patient had a transient change in Modified Rankin scale score from baseline as a result of different unrelated procedure.

CONCLUSION

Our preliminary results demonstrate feasibility of the use of flow diverter stent for treatment of aneurysms of the pericallosal artery with rate of aneurysm occlusion comparable to literature and without evidence of increased procedural or short-term morbidity. A long-term and larger cohort study is needed to validate our findings.

Microsurgical Management of Intracranial Aneurysms After Failed Flow Diversion

BACKGROUND

Flow diversion has become increasingly popular for treatment of cerebral aneurysms in the past few years. In an increasing number of patients with aneurysms, flow diversion (FD) has failed, with a paucity of reported data regarding salvage treatment for these challenging cases.

METHODS

We present a multicenter series of 13 aneurysms for which FD failed and that were subsequently treated with open surgery. We also present a review of the reported data regarding operative management of aneurysms after unsuccessful FD.

RESULTS

Twelve patients with 13 aneurysms were included in the present study. All 12 patients had undergone surgery after FD because of persistent aneurysm filling, mass effect, or aneurysm rupture. The patients underwent aneurysm clipping and parent vessel reconstruction, decompression of the aneurysm mass, occlusion of proximal flow to the aneurysm, or aneurysm trapping with or without extracranial-intracranial artery bypass.

CONCLUSIONS

Aneurysms for which FD fails present a variety of unique and challenging management situations that will likely be encountered with increased frequency, given the popularity of FD. Microsurgical salvage options require individualized care tailored to the underlying pathological features, patient characteristics, and surgical expertise.

The p48MW Flow Diverter-Initial Human Experience

Background and Purpose

The use of flow diverters to treat aneurysms arising from small caliber parent vessels has been reported. This article reports the results of the first in experiences with the p48MW (p48 Movable Wire) in humans, a device specifically designed to target vessels 1.75–3 mm in diameter.

Methods

This monocentric study retrospectively reviewed the prospectively maintained database to identify all patients treated with the p48MW device between January 2017 and January 2019 at this institution. Patient demographics, aneurysm characteristics, angiographic and clinical follow-up were recorded as well as complications.

Results

A total of 25 patients (20 female) with an average age of 55 ± 12.9 years (range 34–84) with 25 aneurysms were identified. The majority of the aneurysms was located in the anterior circulation (19/25, 76%). The average aneurysm dome width was 3.98 ± 3.6 mm (range 1.2–13 mm). Complete occlusion was seen in 18/24 (75%) aneurysms with neck remnants in 1/24 (4.2%) and continued aneurysm filling seen in the remaining cases (5/24, 20.8%). Adequate occlusion was seen in 79.2% of aneurysms (Raymond Roy Classification [RRC] grade I or II) during the follow-up period. There was a single technical complication with inappropriate deployment of the first p48MW. There was a single clinical complication (4%); however, the patient made a complete recovery (modified Rankin Scale [mRS] 0) and one patient died secondary to uncontrollable status epilepticus following acute subarachnoid hemorrhage unrelated to the treatment.

Conclusion

The p48MW is safe and effective for the treatment of aneurysms including those arising from distal vessels.

Impact of age on cerebral aneurysm occlusion after flow diversion

The purpose of this study was to evaluate safety and efficacy of the pipeline embolization device (PED) in different patient age groups with unruptured intracranial aneurysms (UIA). All patients with UIA treated with the PED between 2011 and 2017 were included. Based on their age, patients were trichotomized to: young (≤45 years), middle-aged (46 to <65 years) and older (≥65 years) groups. Patient's vascular risk factors, presenting symptoms and mRS on admission were collected. Follow-up imaging was evaluated for presence/absence of aneurysm occlusion. Clinical outcome at discharge, 3-9 months and 12-18 months was also documented when available. A total of 260 patients harboring 307 aneurysms (young = 57, middle-age = 144 and older age group = 64). Most aneurysms were located in the anterior circulation (94.8%). Overall morbidity and mortality was 2.3% each (6/260). At 3-9 months near complete to complete aneurysm occlusion was 82.5% (47/57) in the young age group, 82.6% (100/121) in the middle age, and 70.2% (40/57) in the older age group. At 12-18-month, near complete to complete occlusion was 100% in the young age group (32/32), 91.4% (64/70) in the middle age, and 78.4% (29/37) in the older age group. After adjustment for potential confounders, older age patients less frequently achieved near complete to complete occlusion by 3 years than younger subjects (p = 0.009, HR 1.34 95%, CI 1.08-1.66). Our results indicate feasibility and safety of PED across different age groups. Further study is required to determine age-related factors relating to aneurysm occlusion after PED to improve outcome and patient counseling.

Predicting Outcomes for Cerebral Aneurysms Treated with Flow Diversion: A Comparison Between 4 Grading Scales

OBJECTIVE

Despite the development of 4 grading scales of angiographic outcome after flow diversion for cerebral aneurysms, none have been widely adopted in the neurosurgical literature, nor have any been validated in an independent dataset. We evaluated the reported grading scales for their ability to predict aneurysm occlusion at follow-up.

METHODS

Four reported grading scales were applied in a retrospective analysis of our prospectively maintained institutional database of patients with intracranial aneurysms treated with flow-diverting stents. Analysis of patient factors, aneurysm factors, and outcomes was made to compare the grading scales' ability to predict aneurysm occlusion.

RESULTS

Ninety-nine aneurysms in 90 patients treated at our institution between 2011 and 2018 were included in the analysis. Lower Flow-Diverting Stent Score (FDSS) scores were associated with higher rates of aneurysm occlusion at final follow-up (P=0.004). The OKM, Kamran-Byrne, and SMART scales scores were not associated with aneurysm occlusion at final follow-up even after adjustments for baseline differences. Area under the receiver operating characteristic curve for the FDSS was 0.675 (0.534-0.816).

CONCLUSIONS

Although the FDSS was the only reported grading scale that was significantly associated with occlusion at follow-up, its ability to predict occlusion fell below the typical level for widespread clinical utility. The high rate of eventual occlusion of most aneurysms after flow diversion likely limits the clinical utility of a grading score for this application.

Aneurysms with persistent filling after failed treatment with the Pipeline embolization device

OBJECTIVE

The Pipeline embolization device (PED) has become a valuable tool in the treatment of cerebral aneurysms. Although failures with PED treatment have been reported, the characteristics and course of these aneurysms remain a topic of uncertainty.

METHODS

Electronic medical records and imaging studies were reviewed for all patients treated with the PED between July 2010 and March 2015 to identify characteristics of patients and aneurysms with residual filling after PED treatment.

RESULTS

Of 316 cases treated at a single institution, 281 patients had a long-term follow-up. A total of 52 (16.4%) aneurysms with residual filling were identified and constituted the study population. The mean patient age in this population was 58.8 years. The mean aneurysm size was 10.1 mm ± 7.15 mm. Twelve aneurysms were fusiform (23%). Of the aneurysms with residual filling, there were 20 carotid ophthalmic (CO) aneurysms (20% of all CO aneurysms treated), 10 other paraclinoid aneurysms (16.4% of all paraclinoid aneurysms), 7 posterior communicating artery (PCoA) aneurysms (21.9% of all PCoA aneurysms), 7 cavernous internal carotid artery (ICA) aneurysms (14.9% of all cavernous ICA aneurysms), 4 vertebrobasilar (VB) junction aneurysms (14.8% of all VB junction aneurysms), and 3 middle cerebral artery (MCA) aneurysms (25% of all MCA aneurysms). Eleven patients underwent placement of more than one PED (21.2%), with a mean number of devices of 1.28 per case. Eight of 12 aneurysms were previously treated with a stent (15.4%). Nineteen patients underwent re-treatment (36.5%); the 33 patients who did not undergo re-treatment (63.5%) were monitored by angiography or noninvasive imaging. In multivariate analysis, age older than 65 years (OR 2.65, 95% CI 1.33-5.28; p = 0.05), prior stent placement across the target aneurysm (OR 2.94, 95% CI 1.15-7.51; p = 0.02), aneurysm location in the distal anterior circulation (MCA, PCoA, and anterior choroidal artery: OR 2.72, 95% CI 1.19-6.18; p = 0.017), and longer follow-up duration (OR 1.06, 95% CI 1.03-1.09; p < 0.001) were associated with incomplete aneurysm occlusion.

CONCLUSIONS

While the PED can allow for treatment of large, broad-necked aneurysms with high efficacy, treatment failures do occur (16.4%). Aneurysm size, shape, and previous treatment may influence treatment outcome.

Clinical application of high-resolution MRI in combination with digital subtraction angiography in the diagnosis of vertebrobasilar artery dissecting aneurysm: An observational study (STROBE compliant)

Vertebrobasilar artery dissecting aneurysm (VBA-DA) is associated with serious complications and poor prognosis in patients. High-resolution magnetic resonance imaging (HR-MRI) is a noninvasive method for the diagnosis of VBA-DA.VBA-DAs were classified according to the feature of HR-MRI in combination with digital subtraction angiography (DSA), and the clinical outcomes of different types of VBA-DAs were analyzed. Thirty-nine patients with 42 VBA-DAs were included and underwent HR-MRI, including three-dimensional T1 weighted image, three-dimensional T2 weighted image (3D-T2WI), three-dimensional time of flight MRA (3D-TOF-MRA), and three-dimensional fast imaging employing steady state acquisition (3D-FIESTA), and hematoma and flaps were compared. The follow-up was 3 to 25 months. The VBA-DAs were classified based on the images of HR-MRI and DSA, and the prognosis was analyzed.VBA-DAs more frequently occurred on the vertebral artery, especially on the dominant vertebral artery. 3D-TOF-MRA showed high signal from hematoma, and 3D-FIESTA showed high signal from flaps. Based on HR-MRI images in combination with DSA, VBA-DAs were classified into 4 types: classical, stenosis, spiral, and hemorrhagic. The patients with the classical VBA-DAs had a higher improvement rate and a lower exacerbation rate. The patients with spiral and hemorrhagic VBA-DAs had poor clinical outcomes. The patients with stenosis VBA-DAs had poorer clinical outcomes than classical types and better clinical outcomes than spiral and hemorrhagic types.The detection of intramural hematoma and dissection flap using HR-MRI provides basic information for the diagnosis of VBA-DA. Individualized therapeutic strategies can be designed for the treatment of VBA-DAs with different features of DSA and HR-MRI.

The Silk Vista Baby: Initial experience and report of two cases

In this report, we present two cases using a novel flow diverter, the Silk Vista Baby, to treat aneurysms successfully, both ruptured and unruptured, that would have been difficult to treat using alternative flow diverters. We describe the clinical and radiological features, outcome and the unique features of the Silk Vista Baby flow diverter.

Pipeline for Distal Cerebral Circulation Aneurysms

BACKGROUND

Pipeline embolization device (PED; Medtronic, Dublin, Ireland) utilization is not limited to the treatment of giant wide-necked aneurysms. It has been expanded to handle small blisters, fusiforms, and dissecting intracranial aneurysms.

OBJECTIVE

To report the use of the PED in various off-label distal cerebral circulation (DCC) arteries with a follow-up to assess clinical outcomes.

METHODS

Between 2011 and 2016, of 437 consecutive patients, 23 patients with aneurysms located in DCCs were treated with PED. Data on patient presentation, aneurysm characteristics, procedural outcomes, postoperative course, and aneurysm occlusion were gathered. To control confounding, we used multivariable logistic regression and propensity score conditioning.

RESULTS

A total of 437 patients (mean age 52.12 years; 62 women [14.2%]) underwent treatment with PED in our institution. Twenty-three of 437 (5.2%) received a pipeline in a distal artery: 11/23 middle cerebral artery, 6/23 posterior cerebral artery, 3/23 anterior cerebral artery (A1/A2, pericallosal artery), and 3/23 posterior inferior cerebellar artery. Twenty percent of the aneurysms were treated in the past, 10% had previously ruptured, and 5.9% ruptured at presentation to our hospital. The mean aneurysm size was 9.0 ± 6 mm. The mean follow-up was 12 mo (SD = 12.5). In multivariable logistic regression, no associations were found between PED deployment in DCCs and aneurysm occlusion or thromboembolic complications. PED use in DCC was associated with a good clinical outcome. Twenty-two people of 23 (95%) had a good clinical outcome in the latest follow-up.

CONCLUSION

Treatment of DCC aneurysms with PED is technically challenging mainly because of the small caliber and tortuosity of the parent arteries. The results of this study further support the safety of flow diverters in the treatment of various distal aneurysms.

Tiny Pipes: 67 Cases of Flow Diversion for Aneurysms in Distal Vessels Measuring Less Than 2.0 mm

BACKGROUND

Flow diversion is increasingly used for off-label treatments of distal circulation aneurysms. Reports of use in sub-2.0-mm vessels are scant.

METHODS

A prospectively collected, institutional review board-approved cerebral aneurysm database was reviewed to identify patients who underwent flow diversion with a 2.5-mm diameter Pipeline embolization device.

RESULTS

Sixty-seven aneurysms were treated in 67 procedures (66 [99%] successful, 64 [96%] single device, 2 [3%] with 2 devices) in 57 patients. Average age was 56 years and 60% were female. Aneurysm location was 51 (76%) anterior cerebral artery, 14 (21%) middle cerebral artery, and 2 (3%) posterior cerebral artery. Aneurysm size was 4.1 ± 3.0 mm (1-20 mm). Safety outcomes included 3 major strokes (4.5%) resulting in permanent neurologic deficit (modified Rankin Scale score 6,4,4), including 1 mortality (1.5%). Acute stent thrombosis was observed intraprocedurally or within 24 hours of each stroke. There were 2 small-volume (<10 cm³, 40 cm³) dependent intracerebral hemorrhage (3.0%) that resolved without permanent neurologic deficit. For effectiveness, 71% of patients underwent follow-up angiography. Complete occlusion was achieved by 88% at 6 months, 86% at 12 months, and 89% at last follow-up. A slight vessel diameter reduction was apparent on average 6.9 months after the procedure, which was statistically significant at the proximal (P = 0.001) but not distal (P = 0.317) device end. Preoperative average parent vessel diameter was 1.9 mm proximally (range, 1.1-2.6 mm) and 1.7 mm distally (range, 1.0-2.3 mm) of the Pipeline embolization device. Follow-up average vessel diameter was 1.7 mm proximally (range, 0.7-2.4 mm) and 1.6 mm distally (range, 0.6-2.1 mm). Flow delay associated with vessel diameter reduction occurred once. There were no cases of asymptomatic vessel occlusion.

CONCLUSIONS

Flow diversion can be safe and effective for aneurysms originating from vessels <2.0 mm in diameter. Heightened vigilance for the prevention and management of acute stent and vessel thrombosis is warranted in these cases.

Endovascular Metal Devices for the Treatment of Cerebrovascular Diseases

Cerebrovascular disease involves various medical disorders that obstruct brain blood vessels or deteriorate cerebral circulation, resulting in ischemic or hemorrhagic stroke. Nowadays, platinum coils with or without biological modification have become routine embolization devices to reduce the risk of cerebral aneurysm bleeding. Additionally, many intracranial stents, flow diverters, and stent retrievers have been invented with uniquely designed structures. To accelerate the translation of these devices into clinical usage, an in-depth understanding of the mechanical and material performance of these metal-based devices is critical. However, considering the more distal location and tortuous anatomic characteristics of cerebral arteries, present devices still risk failing to arrive at target lesions. Consequently, more flexible endovascular devices and novel designs are under urgent demand to overcome the deficiencies of existing devices. Herein, the pros and cons of the current structural designs are discussed when these devices are applied to the treatment of diseases ranging broadly from hemorrhages to ischemic strokes, in order to encourage further development of such kind of devices and investigation of their use in the clinic. Moreover, novel biodegradable materials and drug elution techniques, and the design, safety, and efficacy of personalized devices for further clinical applications in cerebral vasculature are discussed.

High-Definition Zoom Mode, a High-Resolution X-Ray Microscope for Neurointerventional Treatment Procedures: A Blinded-Rater Clinical-Utility Study

BACKGROUND AND PURPOSE

Quality of visualization of treatment devices during critical stages of endovascular interventions, can directly impact their safety and efficacy. Our aim was to compare the visualization of neurointerventional procedures and treatment devices using a 194-μm pixel flat panel detector mode and a 76-μm pixel complementary metal oxide semiconductor detector mode (high definition) of a new-generation x-ray detector system using a blinded-rater study.

MATERIALS AND METHODS

Deployment of flow-diversion devices for the treatment of internal carotid artery aneurysms was performed under flat panel detector and high-definition-mode image guidance in a neurointerventional phantom simulating patient cranium and tissue attenuation, embedded with 3D-printed intracranial vascular models, each with an aneurysm in the ICA segment. Image-sequence pairs of device deployments for each detector mode, under similar exposure and FOV conditions, were evaluated by 2 blinded experienced neurointerventionalists who independently selected their preferred image on the basis of visualization of anatomic features, image noise, and treatment device. They rated their selection as either similar, better, much better, or substantially better than the other choice. Inter- and intrarater agreement was calculated and categorized as poor, moderate, and good.

RESULTS

Both raters demonstrating good inter- and intrarater agreement selected high-definition-mode images with a frequency of at least 95% each and, on average, rated the high-definition images as much better than flat panel detector images with a frequency of 73% from a total of 60 image pairs.

CONCLUSIONS

Due to their higher resolution, high-definition-mode images are sharper and visually preferred compared with the flat panel detector images. The improved imaging provided by the high-definition mode can potentially provide an advantage during neurointerventional procedures.

Acute Treatment of Ruptured Fusiform Posterior Circulation Posterior Cerebral, Superior Cerebellar, and Posterior Inferior Cerebellar Artery Aneurysms With FRED Flow Diverter: Report of 5 Cases

BACKGROUND

Flow diverter (FD) treatment of ruptured fusiform posterior cerebral artery (PCA), posterior inferior cerebellar artery (PICA), and superior cerebellar artery (SCA) aneurysms are limited to single reports.

OBJECTIVE

To study the safety and efficacy of FD treatment for ruptured fusiform aneurysms of the PCA, SCA, and PICA.

METHODS

Five patients with ruptured posterior circulation fusiform aneurysms and treated with a Flow-Redirection Endoluminal Device (FRED/FRED Jr; Microvention, Tustin, California) stent in the acute phase of subarachnoid hemorrhage between 2013 and 2016 were included and reviewed retrospectively.

RESULTS

Two aneurysms located on the PICA, 2 on PCA, and 1 on the SCA. Mean treatment time with FD was 5.8 d (range, 0-11 d) from ictus. The technical success rate was 100%. On admission 2 patients were Hunt and Hess grade 1, 2 patients grade 3, and 1 patient grade 4. At discharge, 4 patients (80%) were independent (modified Ranking Scale (mRS) ≤2) and 1 patient had severe disability (mRS 4). None of the patients had aneurysmal rebleeding. All 5 aneurysms were completely occluded on angiographic follow-up (range, 3-22 mo). One patient had permanent intraprocedural in stent thrombosis and brain infarction. One patient had spontaneous nonaneurysmal intracerebral hemorrhage 1 mo after FD treatment. External ventricular drainage was inserted in 3 patients and ventriculoperitoneal shunt in 2 patients without hemorrhagic complications despite dual antiplatelet therapy.

CONCLUSION

FD could be considered as a treatment option for ruptured fusiform aneurysms located on PCA, PICA, or SCA when other treatment options are challenging.

The use of flow diverters to treat aneurysms of the posterior inferior cerebellar artery: Report of three cases

Objective The objective of this study was to report our experience on the use of flow diverting stents placed within the posterior inferior cerebellar artery (PICA) as a treatment option for aneurysms of the PICA. Methods Three patients with aneurysms of the PICA, both ruptured and unruptured, underwent treatment of their aneurysms with placement of a single flow diverter in the PICA across the neck of the aneurysm. Adjunctive techniques such as coiling were not used. We present the angiographic and clinical follow-up data. Results The procedure was a technical success in all cases and there were no intraoperative complications. Follow-up data were available for two patients and this showed complete occlusion of the aneurysm with the PICA remaining patent. There was no evidence, either clinical or radiological, of medullary or pontine infarction. One patient died during the follow-up period from an unrelated medical illness (community acquired pneumonia). Conclusion Flow diverters can be successfully placed within the PICA to treat both ruptured and unruptured aneurysms, and they represent an alternative treatment option to endovascular coiling or microscopic neurosurgery.

Treatment of Distal Anterior Cerebral Artery Aneurysms with Flow-Diverter Stents: A Single-Center Experience

BACKGROUND AND PURPOSE

Flow diversion for aneurysms beyond the circle of Willis is still debated. Our aim was to evaluate the safety and efficacy of flow diversion treatment of distal anterior cerebral artery aneurysms.

MATERIALS AND METHODS

Consecutive patients with distal anterior cerebral artery aneurysms treated from January 2014 to October 2017 were evaluated retrospectively with prospectively maintained data. Treatment was performed only for unruptured or recanalized aneurysms after coiling. Technical feasibility, procedural complications, aneurysm occlusion (O'Kelly-Marotta grading scale), and clinical outcome were evaluated.

RESULTS

Fifteen patients were included in the study, with 17 distal anterior cerebral artery saccular aneurysms treated with flow-diverter stents. Mean aneurysm size was 4.25 ± 3.9 mm; range, 2-9 mm. Flow diversion was used as retreatment among 6 previously coiled aneurysms (5 ruptured and coiled in the acute phase, and 1 unruptured and recanalized). Stent deployment was technically successful in all cases. During the perioperative period, 1 patient experienced a transient minor stroke (6%), whereas 2 patients reported acute in-stent thrombosis with disabling ischemic complications (13%). Fourteen patients and 16 aneurysms were available during a mean radiologic follow-up of 12 months (range, 3-24 months). Overall, 12 (75%) aneurysms were completely occluded (O'Kelly-Marotta grading scale score D), 1 aneurysm (6%) showed near-complete occlusion (O'Kelly-Marotta grading scale score C), and 3 aneurysms (19%) were incompletely occluded (O'Kelly-Marotta grading scale, score B). All 6 aneurysms previously coiled were completely occluded after flow diversion, whereas 70% of aneurysms treated with flow diverters alone showed complete/near-complete occlusion (O'Kelly-Marotta grading scale C-D). There were no cases of aneurysm rupture, in-stent occlusion, or retreatment during long-term follow-up.

CONCLUSIONS

Treatment of distal anterior cerebral artery aneurysms with flow-diverter stents is feasible and effective, with high rates of aneurysm occlusion. Flow diversion plus coiling, in the retreatment of lesions previously coiled, allowed higher rates of occlusion compared with flow diverters alone. However, the risk of ischemic complications is not negligible, and flow-diversion treatment should be evaluated only for aneurysms not amenable to simple coil embolization.

Endovascular Management of Multiple Dysplastic Aneurysms in a Young Man with an Unknown Underlying Cause: A Case Report and Review of the Literature

BACKGROUND

Intracranial aneurysms are the leading cause of nontraumatic subarachnoid hemorrhage and are most commonly associated with the anterior cerebral artery (ACA) and anterior communicating artery complex. We describe the presentation and management of a 27-year-old man with concurrent bilateral A1-2 junction aneurysms and fusiform intraorbital ophthalmic artery (OA) aneurysms.

CASE DESCRIPTION

A 27-year-old man with no past medical history presented with 3 months of headaches. Imaging showed a large dysplastic left A1-2 junction aneurysm and a smaller saccular right A1-2 junction aneurysm, with potentially adherent domes. Two fusiform aneurysms of the intraorbital segment of the left OA were also identified. The patient underwent coil-assisted pipeline embolization of the left A1-A2 aneurysm, with complete obliteration and reconstitution of the normal parent vessel. The patient underwent coil embolization of the right A1-2 aneurysm 3 weeks later, which was found to have grown significantly at the time of treatment. Three-month follow-up showed spontaneous resolution of the OA aneurysms, persistent obliteration of the left aneurysm, and significant recurrence of the right aneurysm, which was treated with stent-assisted coil embolization. A second recurrence 3 months later was successfully treated with repeat coiling. At the time of this treatment, the patient was also found to have 2 de novo distal middle cerebral artery and ACA dysplastic aneurysms, which were not treated. Follow-up angiography 6 weeks later showed stable complete obliteration of the right A1-2 aneurysm and interval complete resolution of the dysplastic middle cerebral artery aneurysm. The distal ACA aneurysm was observed to have minimally increased in size; however, the parent vessel showed signs of interval partial thrombosis with contrast stasis within the aneurysm. This final aneurysm is being followed with serial imaging. The patient remains neurologically intact with complete resolution of his headaches.

CONCLUSIONS

We report the case of a young man with no past medical history who presented with multiple dysplastic aneurysms. Successful staged endovascular intervention resulted in obliteration of aneurysms with spontaneous obliteration of the intraorbital OA aneurysms observed at 3 months. We present this case to review the multiple challenges of managing complex ACA aneurysms and to highlight the usefulness of endovascular intervention in their treatment.

Multicenter Experience with FRED Jr Flow Re-Direction Endoluminal Device for Intracranial Aneurysms in Small Arteries

BACKGROUND AND PURPOSE

Flow diverters are emerging as an endovascular treatment alternative for proximally located intracranial aneurysms. However, treatment of aneurysms at and beyond the circle of Willis is not well-established. We assessed the clinical safety and efficacy of the Flow Re-Direction Endoluminal Device Jr (FRED Jr) dedicated to small-vessel diameters between 2.0 and 3.0 mm.

MATERIALS AND METHODS

This was a multicenter observational clinical study of 42 patients with 47 aneurysms treated by a flow-direction technique with the FRED Jr. The primary end point for clinical safety was the absence of death, major or minor stroke, and TIA. The primary end point for treatment efficacy was complete and near-complete occlusion according to the O'Kelly-Marotta grading scale at follow-up after 1, 6, and 12 months.

RESULTS

The FRED Jr deployment was technically successful in all cases. In 39/42 (93%) patients, the primary safety end point was reached; in the 3 remaining patients, 1 disabling ischemic stroke, 1 minor stroke with complete recovery at discharge, and 1 TIA were observed. Two asymptomatic, completely reversible side-branch occlusions occurred. Angiographic (DSA or flat panel CT) and clinical follow-up were available after 1 month in 41/47 (87%), 6 months in 27/47 (57%), and 12 months in 11/47 (23%) aneurysms. The primary efficacy end point was reached at 1 month in 27/41 (66%), at 6 months in 21/27 (78%), and at 12 months in 11/11 (100%) aneurysms.

CONCLUSIONS

Deployment of the FRED Jr is safe and effective in the treatment of intracranial aneurysms located in small vessels.

Off-label uses of the Pipeline embolization device: a review of the literature

The Pipeline embolization device (PED) is the most widely used flow diverter in endovascular neurosurgery. In 2011, the device received FDA approval for the treatment of large and giant aneurysms in the internal carotid artery extending from the petrous to the superior hypophyseal segments. However, as popularity of the device grew and neurosurgeons gained more experience, its use has extended to several other indications. Some of these off-label uses include previously treated aneurysms, acutely ruptured aneurysms, small aneurysms, distal circulation aneurysms, posterior circulation aneurysms, fusiform aneurysms, dissecting aneurysms, pseudoaneurysms, and even carotid-cavernous fistulas. The authors present a literature review of the safety and efficacy of the PED in these off-label uses.

Endovascular Treatment of Complex Distal Posterior Cerebral Artery Aneurysms with the Pipeline Embolization Device

OBJECTIVE

To assess the safety and efficacy of the Pipeline Embolization Device (PED) for endovascular treatment of complex, distal posterior cerebral artery (PCA) aneurysms.

METHODS

We conducted a retrospective review of patients who underwent endovascular treatment of complex PCA aneurysms with PED from November 2012 to December 2015. A total of 4 patients were identified and treated. Twelve-month angiographic and clinical follow-up was available for all patients.

RESULTS

Mean aneurysm size (largest diameter) was 10.0 mm, and all aneurysms originated at the P2 segment or beyond. Technical success was achieved in all patients. All patients were treated with a single PED; adjunctive intrasaccular coil was also placed in one patient. All patients achieved a favorable postprocedural outcome (modified Rankin Scale score = 0) with no new neurologic deficits. No patients experienced neurologic complications or perforator infarction, and presenting symptoms resolved in all patients. Follow-up cerebral angiography at 12 months in 3 patients showed complete occlusion (Raymond-Roy Occlusion Classification class 1) and minimal residual aneurysm filling (Raymond-Roy Occlusion Classification class 2) in 1 patient. A small degree of focal stenosis was present in 2 patients within the PED at 12-month follow-up that was associated with mild decrease in flow within the distal PCA branches.

CONCLUSIONS

PED use provides a practical and viable treatment option for complex, distal PCA aneurysms. Based on our limited institutional experience, PED use for treatment of complex, distal PCA aneurysms in select patients appears safe and effective.

Preliminary Experience with Stent-Assisted Coiling of Aneurysms Arising from Small (<2.5 mm) Cerebral Vessels Using The Low-Profile Visualized Intraluminal Support Device

BACKGROUND AND PURPOSE

The Low-Profile Visualized Intraluminal Support (LVIS) stent is a new device recently introduced for the treatment of wide-neck intracranial aneurysms. This single-center study presents the authors' preliminary experience using the LVIS stent to treat saccular aneurysms with parent arteries smaller than 2.5 mm.

MATERIALS AND METHODS

Aneurysms with a LVIS stent used in a small parent vessel (<2.5 mm in diameter) between October 2014 and April 2016 were included. Procedure-related complications, angiographic results, clinical outcomes, and midterm follow-up data were analyzed retrospectively.

RESULTS

A total of 22 patients was studied, including 5 ruptured and 17 unruptured aneurysms. Most of the aneurysms were located in the anterior circulation (90.9%). Stent placement in the parent arteries measuring 1.7-2.4 mm in diameter (mean, 2.1 mm) was successful in 100% of cases. Procedure-related complication developed in 1 patient (4.5%) who presented with aneurysm rupture. No permanent morbidity and mortality occurred. Immediate angiographic outcome showed complete occlusion in 8 aneurysms (36.4%), neck residual in 8 (36.4%), and residual aneurysm in 6 (27.3%). All patients underwent angiographic follow-up at a mean of 8.3 months, which revealed complete occlusion in 18 (81.8%) patients, neck remnant in 3 (13.6%), and residual sac in 1 (4.5%). No recanalization of the target aneurysm was observed. There was 1 case with asymptomatic in-stent stenosis.

CONCLUSIONS

Our preliminary results show that the deployment of LVIS stents in small vessels is feasible, safe, and effective in the midterm. Larger studies with long-term follow-up are needed to validate our promising results.

Endovascular flow diversion for treatment of anterior communicating artery region cerebral aneurysms: a single-center cohort of 50 cases

BACKGROUND

Flow diversion represents a novel but definitive treatment for recurrent and difficult-to-coil aneurysms of the anterior communicating artery (ACoA) region, of which reports are limited.

OBJECTIVE

To determine the effectiveness of the Pipeline embolization device (PED) in treating aneurysms in the ACoA region.

METHODS

We retrospectively reviewed an IRB-approved database of patients with an aneurysm at a single institution for patients with ACoA or A1-A2 aneurysms treated with PED. Data analyzed included demographics, aneurysm characteristics, procedural details, follow-up results, and outcomes.

RESULTS

A total of 50 procedures were performed on 41 patients, including seven patients who underwent bilateral 'H-pipe' PED placement. The average age was 56 years and 46% of the patients were female. The average aneurysm size was 4.5 mm, and two large (>10 mm) aneurysms were treated. The vessel of origin was either the ACoA (26 aneurysms, 63%) or the A1-A2 junction (15 aneurysms, 37%). Eighteen patients (44%) had prior subarachnoid hemorrhage and 20 had previously been treated either with clipping (6 aneurysms, 15%) or coiling (14 aneurysms, 34%). Procedural success was achieved in 48/50 cases (96%) and two cases were aborted. Coils were deployed adjunctively in two cases (4%). Procedural outcomes included no deaths, one major ischemic stroke (2%), and two patients with intracranial hemorrhage (4%). Complete aneurysm occlusion was achieved in 81% of patients at 6 months and 85% of patients at last follow-up digital subtraction angiography.

CONCLUSIONS

The PED can be used safely and effectively in the treatment of aneurysms of the ACoA region. This represents a good alternative treatment option to microsurgical clipping and endovascular coiling.