Immediate and midterm results following treatment of recently ruptured intracranial aneurysms with the Pipeline embolization device

Treatment of ruptured intracranial aneurysms with parent artery flow diverter devices: A comprehensive systematic review and meta-analysis

BACKGROUND

Surgical clipping and endovascular coiling are well-established treatments for acutely ruptured intracranial aneurysms leading to acute subarachnoid hemorrhage (aSAH). However, these modalities have limitations, particularly in cases involving wide-necked, bifurcating, or dissecting aneurysms. Flow diverter (FD) devices, initially used for unruptured aneurysms, have emerged as an alternative treatment for ruptured aneurysms despite concerns about hemorrhagic complications.

AIMS

This study aimed to perform a comprehensive systematic review and meta-analysis to assess the efficacy and safety of parental artery FD devices in treating ruptured intracranial aneurysms.

METHODS

A systematic search was conducted in Medline, Embase, and Cochrane databases from inception to July 2024. The inclusion criteria focused on studies involving patients with acutely ruptured aneurysms treated with parental artery FDs, with or without adjunctive coiling. Studies were required to report clear, stratified data specific to the population of interest, and include more than five patients. Exclusion criteria included studies on non-ruptured aneurysms, intrasaccular flow diversion devices, or previously clipped aneurysms treated with FD. Data extraction was performed independently by two authors, and statistical analysis included single proportion analysis with 95% confidence intervals under a random-effects model, using R Studio. The primary outcome was the rate of aneurysm occlusion at follow-up.

SUMMARY OF REVIEW

A total of 60 studies encompassing 1300 patients were included. The primary outcome analysis revealed a 90% (95% CI: 87-92%; I2 = 51%) rate of total occlusion at follow-up. Subgroup analysis indicated an occlusion rate of 89% for anterior circulation aneurysms and 96% for posterior circulation aneurysms. Intraoperative complications occurred in 6% of cases, while postoperative complications were observed in 13%. Rebleeding rates were low at 1%, with a 2% need for retreatment. Good functional outcomes (mRS ⩽ 2) were achieved in 82% of patients, and the overall mortality rate was 4%.

CONCLUSIONS

FD devices demonstrated high rates of aneurysm occlusion and favorable functional outcomes in patients with acutely ruptured intracranial aneurysms. However, the low mortality rate and favorable outcomes observed may reflect selection bias toward patients with less severe SAH. Despite a modest complication rate, the overall safety and efficacy of FD devices suggest they may be a viable alternative to traditional treatments for specific aneurysm types. Further studies, including a broader spectrum of SAH severities, are warranted to optimize their use in clinical practice.

Heparin Coating Decreases the Thrombotic Signature of Flow Diverter Stents

PURPOSE

Flow diverter stents (FDS) are used to treat aneurysms by modifying the intraaneurysmal hemodynamics and promoting a prothrombotic milieu. Thrombotic in-stent stenosis (ISS) is a common complication of endovascular treatment for intracranial aneurysms with flow diverter stents. The dominant approach to address ISS has been to either increase the dose of antiplatelet therapy agents or extend dual antiplatelet therapy (DAPT) causing ISS to resolve, while potentially exacerbating the side effects associated with DAPT. To decrease the risk of thrombotic ISS, surface coatings have been applied to flow diverter stents with promising results.

METHODS

The thrombotic signature of a bare metal and a heparin coated FDS was assessed in vitro. The flow diverter stents were exposed to pulsatile blood flow in a one-pass system to assess platelet and fibrin deposition, while flow cytometry was used to assess different markers of platelet activation in blood incubated with flow diverter stents for 30, 60, and 90 minutes.

RESULTS

Immunofluorescence and scanning electron microcopy results demonstrated greater fibrin and platelet deposition on bare metal flow diverter stents, while the heparin coated flow diverter stents had less fibrin and platelet deposition. A greater percentage of platelets were not only activated, but also presented higher levels of activation markers, in blood exposed to the bare metal flow diverter stents at the 90 minute time point in comparison to the heparin coated FDS.

CONCLUSION

The findings demonstrate that heparin coated flow diverter stents are characterized by a lower thrombotic signature than bare metal flow diverter stents and raise the possibility of an additional therapeutic option to treat intracranial aneurysms.

Multicenter analysis of flow diversion for recurrent/persistent intracranial aneurysms after stent-assisted coiling

BACKGROUND

Flow-diverter stents (FDS) have become the standard of care for a wide range of intracranial aneurysms, but their efficacy/safety in the context of recurrent/recanalized aneurysms following stent-assisted coiling (SAC) is not well established. We evaluate the outcomes of FDS retreatment in a large multicenter cohort.

METHODS

We retrospectively analyzed data from 118 patients across 22 institutions who underwent FDS retreatment for recurrent/persistent aneurysms after SAC (2008-22). The primary outcome was angiographic occlusion status at last follow-up, categorized as complete (100%), near-complete (90-99%), or incomplete (<90%) occlusion. Secondary outcomes included procedural complications and clinical outcomes measured by the modified Rankin Scale (mRS).

RESULTS

A total of 118 patients (median age 57, 74.6% female) with median follow-up of 15.3 months were identified. Complete occlusion was achieved in 62.5% and near-complete occlusion in 25%. FDS deployment within the pre-existing stent was successful in 98.3% of cases. Major complications occurred in 3.4% of cases, including postoperative aneurysmal rupture with resultant mortality (1.6%) and thromboembolic events with long-term disability (1.6%). Favorable clinical outcomes (mRS 0-2) were observed in 95.1% of patients. Wider aneurysm neck diameter was a significant predictor of incomplete occlusion (adjusted OR (aOR) 1.23 per mm, P=0.044), with male sex trending towards association with non-occlusion (aOR 3.2, P=0.07), while baseline hypertension was associated with complete occlusion (aOR 0.32, P=0.048).

CONCLUSIONS

FDS treatment for recurrent/residual aneurysms after SAC represents a viable treatment option for these challenging cases with acceptable safety and reasonable occlusion rates, although lower than de novo FDS occlusion rates.

Treatment of Ruptured Anterior Choroidal Artery Aneurysms by Acute Coiling Followed by Flow Diversion

BACKGROUND

Flow-diverter treatments are successful endovascular treatments in protecting important perforating branches during aneurysm treatments. Because these treatments are performed under antiplatelet therapy, acute flow-diverter treatments in ruptured aneurysms are still controversial. Acute coiling followed by flow diversion has emerged as an intriguing and feasible treatment option for ruptured anterior choroidal artery aneurysm treatment. As a single-center retrospective case series study, this study reported the clinical and angiographic results of staged endovascular treatment in patients with a ruptured anterior choroidal aneurysm.

METHODS

This is a single-center retrospective case series study between March 2011 and May 2021. Patients with ruptured anterior choroidal aneurysm received flow-diverter therapy in a different session after acute coiling. Patients treated with primary coiling or only flow diversion were excluded. Preoperative demographic and presenting symptoms, aneurysm morphology, perioperative and postoperative complications, and long-term clinical and angiographic outcome as measured using the modified Rankin Scale and O'Kelly Morata Grading scale and also Raymond-Roy occlusion classification respectively.

RESULTS

Sixteen patients underwent coiling in the acute phase to undergo flow diversion later. The mean maximum aneurysm diameter is 5.44 ± 3.39 mm. All patients had a subarachnoid hemorrhage and were treated acutely between days 0 and 3 of acute bleeding. The mean age at the presentation was 54.12 ± 12 years (32-73 years). Two patients (12.5%) had minor ischemic complications, which are seen on magnetic resonance angiography as clinically silent infarcts, after the procedure. One patient (6.2%) had a technical complication with the flow-diverter shortening and deployed a second flow diverter telescopically. No mortality or permanent morbidity was reported. The mean interval time between the 2 treatments was 24.06 ± 11.83 days. All patients were followed up with digital subtraction angiography; 14/16 patients (87.5%) had aneurysms that were completely occluded and 2/16 (12.5%) showed near-complete occlusion. Mean follow-up was 16.62 ± 3.22 months; all patients had modified Rankin Scale scores ≤2; 14/16 (87.5%) had a total occlusion 14/16 (87.5%) had near-complete occlusion. None of the patients had retreatment or rebleeding.

CONCLUSIONS

Staged treatment of ruptured anterior choroidal artery aneurysms with acute coiling and flow-diverter treatment after recovery from subarachnoid hemorrhage is safe and effective. In this series, no cases of rebleeding occurred during the interval between coiling and flow diversion. Staged treatment should be considered a valid option in patients with challenging ruptured anterior choroidal aneurysms.

The optimal management of ruptured basilar artery dissecting aneurysms: a case series and scoping review

The natural history of ruptured basilar artery dissecting aneurysms (BADAs) remains unclear compared to that of ruptured vertebral artery dissecting aneurysms (VADAs). In this study, we investigated the natural history and optimal management of ruptured BADAs. We identified 17 patients with ruptured BADA among 4586 patients with aneurysmal subarachnoid hemorrhage (SAH) treated in seven participating hospitals. A scoping literature review was undertaken to investigate prognostic factors. Six patients among the profiled patients (35.3%) died, all with poor SAH grades (World Federation of Neurological Societies Grade IV and V). Rebleeding after admission was observed in three patients (17.6%) with poor SAH grades. Aggressive treatment and conservative management were initiated in seven and ten patients, respectively. Patients with good SAH grades had significantly higher favorable treatment outcomes than those with poor grades (83.3% vs. 9.1%, P = 0.005). Moreover, based on a scoping review of 158 cases with ruptured BADA, including the patients from our series, approximately 90% of patients with good SAH grades had favorable outcomes. A good SAH grade and no rebleeding after admission were favorable prognostic factors (P < 0.0001 and P = 0.002, respectively). The rebleeding rates were 20.2%, 13.3%, and 6.3% for dilated, pearl and string, and stenotic lesions, respectively. We concluded that the natural history of isolated ruptured BADAs may be better than that of VADAs. Although definitive treatment, if possible, is undoubtedly important, conservative management with careful radiological follow-up for morphological changes might be a viable option for patients in good clinical condition and with non-dilated lesions.

Outcomes after Flow Diverter Treatment in Subarachnoid Hemorrhage: A Meta-Analysis and Development of a Clinical Prediction Model (OUTFLOW)

Background: patients with a subarachnoid hemorrhage (SAH) might need a flow diverter (FD) placement for complex acutely ruptured intracranial aneurysms (IAs). We conducted a meta-analysis and developed a prediction model to estimate the favorable clinical outcome after the FD treatment in acutely ruptured IAs. Methods: a systematic literature search was performed from 2010 to January 2021 in PubMed and Embase databases. Studies with more than five patients treated with FDs within fifteen days were included. In total, 1157 studies were identified. The primary outcome measure was the favorable clinical outcome (mRS 0–2). Secondary outcome measures were complete occlusion rates, aneurysm rebleeding, permanent neurologic deficit caused by procedure-related complications, and all-cause mortality. A prediction model was constructed using individual patient-level data. Results: 26 retrospective studies with 357 patients and 368 aneurysms were included. The pooled rates of the favorable clinical outcome, mortality, and complete aneurysm occlusion were 73.7% (95% CI 64.7–81.0), 17.1% (95% CI 13.3–21.8), and 85.6% (95% CI 80.4–89.6), respectively. Rebleeding occurred in 3% of aneurysms (11/368). The c-statistic of the final model was 0.83 (95% CI 0.76–0.89). All the studies provided a very low quality of evidence. Conclusions: FD treatment can be considered for complex ruptured IAs. Despite high complication rates, the pooled clinical outcomes seem favorable. The prediction model needs to be validated by larger prospective studies before clinical application.

Flow diversion for acutely ruptured intracranial aneurysms treatment: A retrospective study and literature review

OBJECTIVE

Flow diversion is becoming an increasingly established practice for the treatment of acutely ruptured intracranial aneurysms. In this study the authors present a literature review and meta-analysis, adding a retrospective review of institutional registry on emergency treatment of aRIA with flow diverter stent.

MATERIALS AND METHODS

A systematic search of PubMed, SCOPUS, Ovid MEDLINE, and Ovid EMBASE was performed on April 20^th, 2021, extrapolating 35 articles. R language 'meta' and 'metafor' packages were used for data pooling. The DerSimonian-Laird model was used to calculate the pooled effect. The I² value and Q statistic evaluated study heterogeneity. Additionally, the authors retrospectively reviewed their institutional database for the treatment and outcomes of all patients with acutely ruptured intracranial aneurysms treated with flow diverter stent placement from May 2010 to November 2020 was performed.

RESULTS

From the systematic literature review and meta-analysis, the pooled proportion of complete aneurysm occlusion was 78%, with a pooled rate of 79%, 71%, 80%, and 50% for dissecting, saccular, fusiform, and mycotic aneurysms, respectively. The pooled proportion of aneurysm rebleeding and intrastent stenosis was 12% and 15% respectively, for a total of 27% rate. The analysis of authors retrospective register showed an overall mortality rate of 16.7% (3/18), with a low but not negligible postprocedural rebleeding and intrastent thrombosis rates (5.6% and 11.1% respectively).

CONCLUSION

Although increasingly utilized in the management of selected patients with acutely ruptured intracranial aneurysms, flow diversion for acutely ruptured intracranial aneurysms treatment presents rebleeding and intrastent stenosis rates not negligible.

Willis Covered Stent for Treating Intracranial Pseudoaneurysms of the Internal Carotid Artery: A Multi-Institutional Study

OBJECTIVE

This work aimed to retrospectively analyze Willis covered stent (WCS)'s therapeutic efficacy in intracranial pseudoaneurysms (PSAs) of the internal carotid artery (ICA).

METHODS

Between June 2018 and July 2021, 56 individuals with intracranial PSAs of the ICA treated with WCS in three centers were included to analyze information regarding medical records, operative parameters, imaging findings and follow-up data.

RESULTS

All WCSs were successfully targeted to the ICA lesions. Total exclusion of PSA was found in 53 cases (94.6%) right upon surgery, and mild endoleak into the aneurysm remained in 3 cases (5.4%). Intraoperative thrombosis occurred in 1 case (1.8%), and tirofiban was utilized for recanalization. Follow-up by angiography showed total aneurysm occlusion in the total number of individuals, including in the 3 above cases with residual endoleak. In-stent stenosis occurred in 7 (12.5%) patients. No stent-related ischemic event was encountered. Predictive factors of late in-stent stenosis following WCS implantation in this patient group were irregular post-operative antiplatelet treatment (p = 0.015) and C4-C5 segment of the ICA (p = 0.043).

CONCLUSION

WCSs are effective in treating intracranial PSAs of the ICA.

Vertebral artery dissection and associated ruptured intracranial pseudoaneurysm successfully treated with coil assisted flow diversion: A case report and review of the literature

Dissecting intracranial pseudoaneurysms (IPs) are associated with a high incidence of rupture and poor neurologic outcomes. Lesions in the posterior circulation are particularly malignant and pose even greater management challenges. Traditional management consists of microsurgical vessel sacrifice with or without bypass. Flow diversion (FD) in the setting of subarachnoid hemorrhage (SAH) represents a reconstructive treatment option and can be paired with coil embolization to promote more rapid thrombosis of the lesion. We report a case of a ruptured dissecting vertebral artery (VA) IP successfully acutely treated with coil-assisted FD. A 53-year-old male presented with a right V4 dissection spanning the origin of the posterior inferior cerebellar artery and associated ruptured V4 IP. The patient was treated with coil-assisted FD. Oral dual-antiplatelet therapy (DAPT) was initiated during the procedure, and intravenous tirofiban was used as a bridging agent. Immediate obliteration of the IP was achieved, with near-complete resolution of the dissection within 48 h. The patient made a complete recovery, and angiography at 6 weeks confirmed total IP obliteration, reconstruction of the VA, and a patent stent. The use of FD and DAPT in the setting of acute SAH remains controversial. We believe that coil-assisted FD in carefully selected patients offers significant advantages over traditional microsurgical and endovascular options. The risks posed by DAPT and potential for delayed thrombosis with FD can be effectively mitigated with planning and the development of protocols. We discuss the current literature in the context of our case and review the challenges associated with treating these often devastating lesions.

Balloon-Assisted Coils Embolization for Ophthalmic Segment Aneurysms of the Internal Carotid Artery

Objective: To explore the role of balloon-assisted coils technique for ophthalmic segment aneurysms (OSAS).

Methods: Clinical data of 30 patients with OSAS were reviewed between December 2017 and December 2018. OSAS were defined as arising from the internal carotid artery (ICA), reaching from the distal dural ring to the origin of the posterior communicating artery. OSAS were classified into four types based on the angiographic findings. The balloon-assisted coils technique was used for the embolization of aneurysms. The duration of balloon inflation cycles, as well as difficulty and complications during the embolization procedure, were recorded. The immediate angiographic results were evaluated according to the Raymond scale. Clinical results were evaluated based on the MRS score. Follow-ups were performed at 18 months post-embolization by DSA or MRA at our institution.

Results: Thirty-two aneurysms in 30 patients were detected by digital subtraction angiography (DSA), which included 30 unruptured and two ruptured cases. The patients with ruptured aneurysms were grade II status according to the Hunt-Hess scale. Three cases were type A, nine cases were type B, 17 cases were type C, and three cases were type D. According to aneurysm size, there were 19 cases of small, 11 cases of medium, two cases of large aneurysm. Thirty-two aneurysms were successfully embolized in 30 patients by balloon-assisted coils technique. The ophthalmic artery could be protected by an engorged balloon in the procedure, especially for type A aneurysms. Considering that type D aneurysm arises from the side-wall of the artery and near to tortuous ICA siphon, the balloon catheter was inflated to stabilize the microcatheter allowing for overinflation when necessary. The average duration of balloon dilatation was 4 min, and the average time was 2.5 times. Raymond class was one in 28 aneurysms and two in four aneurysms according to the immediate post-embolization angiographic results. All the patients achieved good clinical effects, except for one patient who presented with brain ischemia resulting in dizziness and contralateral limb weakness for 10 h due to prolonged temporary clamping of the responsible ICA. The follow-up angiography results were satisfactory at 18 months post-embolization.

Conclusion: OSAS endovascular treatment with balloon-assisted coils has different advantages in a different classification. The technique is safe, effective, and relatively inexpensive, especially for small and medium OSAS.

Endovascular Treatment of Intracranial Aneurysms

Traditionally, surgical clipping was the only available treatment modality for intracranial aneurysms. However, in the last few decades, the endovascular therapy of intracranial aneurysms (IAs) has seen a tremendous evolution and development. From coiling to flow diversion and flow disruptor devices, endovascular treatment modalities have increased in number and received broader indications throughout the years. In this review article, the treatment modalities for the endovascular management of IAs are presented, emphasizing newer devices and technologies.

Ruptured Intracranial Aneurysms Treated with the Pipeline Embolization Device: A Systematic Review and Pooled Analysis of Individual Patient Data

BACKGROUND

The Pipeline Embolization Device (PED) is a flow-diverting stent for the treatment of intracranial aneurysms and is used off-label for a subset of ruptured aneurysms not amenable to traditional treatment.

PURPOSE

Our aim was to evaluate the safety and efficacy of the PED for treatment of ruptured intracranial aneurysms.

DATA SOURCES

A systematic review of the MEDLINE, EMBASE, and Scopus data bases from January 2011 to March 2020 was performed for articles reporting treatment of ruptured intracranial aneurysms with the PED.

STUDY SELECTION

A total of 12 studies comprising 145 patients with 145 treated aneurysms were included for analysis.

DATA ANALYSIS

Individual patient data were collected. Nonparametric tests were used to compare differences among patients. Logistic regression was used to determine an association with outcome variables.

DATA SYNTHESIS

Mean aneurysm size was 5.9 mm, and most were blister (51.0%) or dissecting (26.9%) in morphology. Three (2.1%) aneurysms reruptured following PED placement. Univariate logistic regression identified larger aneurysm size as a significant predictor of aneurysm rerupture (P = .008). Of patients with radiographic follow-up, 87.5% had complete aneurysm occlusion. Symptomatic neurologic complications occurred in 16.5%.

LIMITATIONS

Analysis was limited by the quality of the included data, most of which were from small case series representing class III medical evidence. No study assessed outcome in a blinded or independently adjudicated manner.

CONCLUSIONS

Most ruptured aneurysms treated with the PED were blister or dissecting aneurysms. Treatment was associated with a rerupture rate of 2.1% and a complete occlusion rate of 87.5%.

A novel treatment of a patient with a giant ruptured middle cerebral artery aneurysm by acute coiling followed by scheduled Pipeline flex placement

OBJECTIVE

Flow diversion in the acute phase of aneurysm rupture or giant aneurysm is limited by the need for dual antiplatelet therapy and the risk of delayed aneurysm rupture. Here, the authors report a scheduled flow-diversion concept for the endovascular treatment of a giant intra-dural aneurysm.

METHODS

A 54-year-old female patient with a ruptured giant middle cerebral artery aneurysm underwent coiling in the acute phase following 1-month scheduled Pipeline flex placement.

RESULTS

The acutely ruptured giant middle cerebral artery aneurysm was treated by flow diversion scheduled at 1 month after conventional coiling. The patient tolerated this treatment strategy well without any neurological deficits after the procedure and during the 3-month follow-up. The aneurysm showed nearly complete obliteration on 3-month follow-up angiogram, and a 6- to 12-month follow-up was scheduled.

CONCLUSIONS

This strategy may be considered as an option in patients presenting with ruptured or unruptured giant intra-dural aneurysms.

Delayed rupture of intracranial aneurysms after placement of intra-luminal flow diverter

BACKGROUND

Though flow diverter is a safe and efficient modality, some patients can experience delayed aneurysmal rupture. The mechanism of delayed rupture is still obscure to us.

METHODS

We performed a systematic search in the PubMed database for patients with delayed rupture of intracranial aneurysms after flow diverter placement.

RESULTS

A total of 36 articles reporting on 60 patients were included in the final analysis. Of the 49 patients with description of presenting symptoms, six (12.2%) patients were incidentally diagnosed, 39 (87.8%) patients were admitted for aneurysmal rupture or mass effect. Multiple flow diverters were used in 38.3% (18/47) of the patients. Coil assistance was applied in 13.0% (7/54) of the patients. Delayed aneurysmal rupture led to intracranial hemorrhage or carotid-cavernous sinus fistula (CCF) in 76.8% (43/56) and 23.2% (13/56) of the patients, respectively. Of the 55 patients with description of outcome, 14 (25.5%) patients achieved good recovery, one (1.8%) patient was severely disabled, 40 (72.7%) patients died. All of the patients in the CCF group survived and experienced good recovery.

CONCLUSION

Increased intra-aneurysmal pressure, destabilization of the aneurysm wall by intra-aneurysmal thrombus, persistent residual intra-aneurysmal flow, characteristics of the specific aneurysm, and mechanical injury by the flow diverter might conjointly contribute to the final delayed rupture. There has been no established preventive measure to decrease the incidence of delayed rupture yet. The treatment and outcome depend on the presentation of delayed rupture. Patients presenting with aneurysm-related intracranial hemorrhage have a dismal outcome. Those presenting with CCFs usually have a satisfactory recovery.

Treatment of Anterior Circulation Aneurysms in the Internal Carotid Artery With Flow Diverters

Several studies have shown the efficacy and feasibility of flow diversion for the endovascular treatment of wide-necked and otherwise anatomically challenging intracranial aneurysms (IA). Technological advances have led to successful long-term occlusion rates and a safety profile for flow-diverter stents that parallels other endovascular and open surgical options for these lesions. With growing indications for use of the Pipeline Embolization Device (PED, Medtronic, Dublin, Ireland) to include IAs up to the internal carotid artery (ICA) terminus, understanding the nuances of this technology is increasingly relevant. Furthermore, there is a growing body of literature on the use of flow diversion to treat distal (up to A2, M2, and P2), ruptured, and posterior circulation aneurysms, although these applications are "off-label" at present. In this manuscript, we discuss the expanding role of flow diversion in the ICA and compare this technique with other endovascular options for the treatment of ICA IAs. We also discuss technical nuances of the deployment of flow diverters for the treatment of challenging lesions and in difficult and tortuous anatomy.

Antiplatelet Therapy for Stent-Assisted Coil of Ruptured Middle Cerebral Artery Bifurcation Aneurysm: Is There a Right Answer?

A variety of modalities exist for treatment of cerebral aneurysms. Stent-assisted coiling is an effective option but poses a challenge regarding antiplatelet therapy. No consensus exists among neuroendovascular surgeons regarding preferred agent, dose, and timing to balance the risk of thromboembolism and hemorrhage. This is especially true in the setting of aneurysmal subarachnoid hemorrhage.

We present a 66-year-old female with history of thrombocytopenia and nonalcoholic cirrhosis who presented with severe headache. Head CT demonstrated a right temporal lobe intraparenchymal hemorrhage with sylvian fissure subarachnoid hemorrhage. Cerebral angiogram showed a 1.5mm x 1.5mm right middle cerebral artery (MCA) bifurcation aneurysm. The patient underwent Y-stent coiling from the right M1 into the right M2 superior division and the right M1 into the right M2 inferior division, with a 1mm x 1cm coil. Given the patient’s thrombocytopenia, only aspirin monotherapy was administered peri-procedural. Shortly thereafter, the patient developed left hemiparesis. Computed tomography angiogram (CTA) demonstrated thrombus within the stent. Thrombectomy was performed with thrombolysis in cerebral infarction (TICI) 3 revascularization and improvement to neurologic baseline. However, that evening she became acutely hypotensive, unresponsive, and ultimately expired due to hemorrhagic cause.

Antiaggregate therapy among neuroendovascular procedures is debated with no clear standard of care. This case highlights the difficult decisions that must be made to balance the risks associated with the use of antiplatelets with ruptured aneurysms.

Rerupture Following Flow Diversion of a Dissecting Aneurysm of the Vertebral Artery: Case Report and Review of the Literature

BACKGROUND

Dissecting aneurysms of the posterior cerebral circulation can wield significant treatment challenges with devastating clinical outcomes. Despite an expanded therapeutic armamentarium, these vascular lesions remain relatively difficult to diagnose and portend high associated morbidity and mortality.

METHODS

A ruptured, fusiform, dissecting aneurysm of the mid V4 segment of the right vertebral artery (VA) distal to the posterior inferior cerebellar artery origin resulted in a Hunt and Hess grade 5, Fisher scale score 4 subarachnoid hemorrhage. The lesion incorporated 360 degrees of the vessel wall and extended across an area measuring 11 mm in length and 6.8 mm in width at maximum dimension. The vascular lesion was treated with 2 overlapping Pipeline Embolization Devices.

RESULTS

Digital subtraction angiography demonstrated an origin of the right posterior inferior cerebellar artery mildly stenosed by the dissecting aneurysm. The left VA was markedly hypoplastic. After deployment of 2 overlapping Pipeline Embolization Devices, the aneurysm neck was well covered with appropriate positioning of the stent construct with good apposition to the vessel wall. There was contrast stasis within the aneurysm. The patient was managed with dual antiplatelet therapy. He demonstrated initial clinical and radiographic improvement. However, on the night of the second postprocedure day, the patient succumbed to rerupture of the aneurysm.

CONCLUSIONS

The literature posits that nonsaccular, fusiform, and dissecting aneurysms of the vertebrobasilar circulation can be occluded with consistency and success using flow diversion techniques. Endovascular treatment of a ruptured dissecting aneurysm of the VA is technically feasible and can be performed with or without parent artery occlusion. Outcomes following flow diversion of the posterior circulation may depend on the location of the dissection and viability of collateral circulation. In the present case, adequate coverage of the aneurysm did not portend a positive outcome.

Expanding Indications for Flow Diverters: Ruptured Aneurysms, Blister Aneurysms, and Dissecting Aneurysms

BACKGROUND

The safety and efficacy of flow diversion (FD) in the treatment of cerebral aneurysms have been reported by many studies. FD has enabled the treatment of complex aneurysms and aneurysms that were previously untreatable by conventional means. It has achieved high rates of obliteration with essentially no recanalization, and its indications have continued to expand, now including ruptured aneurysms, blister aneurysms, and dissecting aneurysms.

OBJECTIVE

To provide a review on the outcomes of studies covering the use of FD in the settings of ruptured, blister, and dissecting aneurysms. In addition, to discuss dual antiplatelet therapy (DAPT) used in preparation for FD deployment in these scenarios, including associated complications with DAPT use in the acute rupture setting.

METHODS

References for this topical review were identified by PubMed searches between January 2000 and January 2019. The search terms “aneurysm”, “flow diverter”, “stent”, “pipeline”, “ruptured”, “blister”, and “dissecting aneurysms” were used.

RESULTS

FD carries a higher complication rate in the acute rupture setting than for unruptured aneurysms. Patient selection is of paramount importance for achieving good functional and angiographic outcomes. DAPT still remains challenging, especially in ruptured aneurysms. Advancements in surface modification of flow diverters can reduce the risk of thromboembolism and perhaps lead to a safer antiplatelet regimen.

CONCLUSION

In summary, FD shows promise to be an effective treatment for ruptured, blister, and dissecting aneurysms.

Endovascular Treatment of Posterior Cerebral Artery Aneurysms With Flow Diversion: Case Series and Systematic Review

BACKGROUND

Flow diversion of posterior cerebral artery (PCA) aneurysms has not been widely reported, possibly owing to concerns regarding parent vessel size and branch vessel coverage.

OBJECTIVE

To examine the safety and effectiveness of PCA aneurysm flow diverter treatment.

METHODS

Retrospective review of PCA aneurysms treated with the Pipeline Embolization Device (PED; Medtronic Inc, Dublin, Ireland) at 3 neurovascular centers, including periprocedural complications and clinical and angiographic outcomes. Systematic review of the literature identified published reports of PCA aneurysms treated with flow diversion. Rates of aneurysm occlusion and complications were calculated, and outcomes of saccular and fusiform aneurysm treatments were compared.

RESULTS

Ten PCA aneurysms in 9 patients were treated with the PED. There were 2 intraprocedural thromboembolic events (20%), including 1 symptomatic infarction and 1 delayed PED thrombosis. Eight of 10 patients returned to or improved from their baseline functional status. Complete aneurysm occlusion with parent vessel preservation was achieved in 75% (6/8) of cases at mean follow-up of 16.7 mo. Eleven of 12 (92%) major branch vessels covered by a PED remained patent. Including the present study, systematic review of 15 studies found a complete aneurysm occlusion rate of 88% (30/34) and complication rate of 26% (10/38), including 5 symptomatic ischemic strokes (13%; 5/38). Fusiform aneurysms more frequently completely occluded compared with saccular aneurysms (100% vs 70%; P = .03) but were associated with a higher complication rate (43% vs 9%; P = .06).

CONCLUSION

The safety and effectiveness profile of flow diverter treatment of PCA aneurysms may be acceptable in select cases.

Morbidity and Mortality in Patients With Posterior Circulation Aneurysms Treated With the Pipeline Embolization Device: A Subgroup Analysis of the International Retrospective Study of the Pipeline Embolization Device

BACKGROUND

The safety of PipelineTM Embolization Device (PED; Medtronic Inc, Dublin, Ireland) in posterior circulation aneurysms is still controversial.

OBJECTIVE

To study complications associated with the treatment of posterior circulation aneurysms by conducting a subgroup analysis from the International Retrospective Study of PED registry.

METHODS

Data from 91 consecutive patients with 95 posterior circulation aneurysms at 17 centers between July 2008 to February 2013 were analyzed. The primary endpoint was defined as any complication leading to neurological morbidity or death. The outcome predictors were calculated using Kaplan-Meier and Cox regression methods.

RESULTS

The mean aneurysm size was 13.8 mm. Aneurysm types were saccular (36.8%), fusiform (29.5%), dissecting (28.4%), and others (5.3%). The median follow-up was 21.1 mo. Twelve (13.2%) patients encountered a primary endpoint event. In multivariate analysis for the primary endpoint, use of ≥3 PEDs and fusiform shape compared with other shapes had hazard ratios (HRs) of 7.77 (95% confidence interval [CI], 2.48-25.86; P = .0007) and 3.48 (95% CI, 1.06-13.39; P = .0488), respectively. The multivariate HR of aneurysm size for neurological morbidity after PED implantation was 1.11 (95% CI, 1.04-1.18; P = .0015), and HRs of ruptured aneurysm and age for neurological mortality were 8.1 (95% CI, 1.31-41.26; P = .0197) and 1.07 (95% CI, 1.02-1.15; P = .0262), respectively. Basilar artery aneurysm had an HR of 3.54 (95% CI, 1.12-14.18, P = .0529) in the univariate analysis for major outcomes.

CONCLUSION

PED implantation may be considered for the treatment of posterior circulation aneurysms, especially of saccular or dissecting type. Our major complications appear to be comparable to those reported previously after clipping and coiling in the literature. Neurointerventionists should consider the shape, size, rupture, and location of complex posterior circulation aneurysms as well as age and PED number before the PED placement.

Effect of aneurysm morphologic parameters on occlusion rates following pipeline embolization

OBJECTIVE

Treatment failures with the use of Pipeline Embolization Device (PED) continue to be observed in up to 18% of patients in large case series. Adjunctive coiling and layering of multiple devices have been shown to improve occlusion rates; however, the optimal treatment strategy with the use of PED has not been established. The purpose of this study is to identify morphological characteristics predictive of treatment failure after PED.

PATIENT AND METHODS

A case control design was used to evaluate the association of aneurysm morphologic parameters with failure after PED placement. Retrospective analysis of patients undergoing PED for elective aneurysm treatment between 2014 and 2017 was performed. Patients who underwent PED placement with at least 12 months follow-up using conventional cerebral angiography were included for further review.

RESULTS

84 patients met inclusion criteria for further analysis. ten patients (11.9%) experienced treatment failure defined by retained flow within the aneurysm and of those eight patients (9.5%) required additional retreatment. On multivariate analysis decreasing aspect ratio and increasing neck width were significant parameters that predicted treatment failure.

CONCLUSION

Aneurysms with small aspect ratio and large neck width may be more likely to experience treatment failure after PED embolization. This subset of aneurysms may therefore benefit from adjunctive coiling to improve occlusion rates. Future prospective studies are needed to validate these findings.

Pipeline embolisation device with shield technology for the treatment of ruptured intracranial aneurysm

Flow diverters have emerged as a safe and effective treatment option for patients with complex unruptured cerebral aneurysms. Their utilisation in patients with ruptured aneurysms poses significant challenges, most notably the need for periprocedural dual antiplatelet medication. We describe the use of the pipeline embolisation device with shield technology in an 88-year-old patient with a complex ruptured posterior communicating artery aneurysm not amenable to microsurgical clipping or coiling alone. The pipeline embolisation device with shield technology utilises a phosphorylcholine coating to decrease thrombotic risk. We describe our antithrombotic protocol and technique to decrease the risk of acute re-rupture. The case highlights the option of using a flow diversion device with antithrombotic coatings in patients with complex ruptured cerebral aneurysms not amenable to coiling or microsurgical clipping.

Early Versus Delayed Flow Diversion for Ruptured Intracranial Aneurysms: A Meta-Analysis

OBJECTIVE

The use and timing of flow diversion for aneurysmal subarachnoid hemorrhage is controversial. The objective of this study is to perform a meta-analysis and systematic review to compare overall complication rate between early versus delayed flow diversion for ruptured aneurysms.

METHODS

A literature search for all eligible articles was performed using PubMed, Cochrane, and Web of Science databases. The primary outcome was the overall complication rate (any complication in the perioperative period), and secondary outcomes were 1) hemorrhage and 2) stroke/death (all hemorrhagic/ischemic strokes and/or death).

RESULTS

Thirteen articles including 142 patients met inclusion criteria. Eighty-nine (62.7%) patients underwent early deployment of flow diverters (i.e., 2 days or less). The odds ratio for overall complication rate with early versus delayed flow diversion was 0.95 (95% confidence interval [CI] 0.36-2.49, P = 0.42). The odds ratio for the secondary outcome of hemorrhagic complication for early versus delayed flow diversion was 1.44 (95% CI 0.45-4.52, P = 0.87) and of stroke/death was 1.67 (95% CI 0.5-4.9, P = 0.69). The odds ratio of early versus delayed flow diversion for blister/dissecting/fusiform aneurysms was 0.82 (95% CI 0.29-2.30) and for saccular/giant aneurysms was 2.23 (95% CI 0.17-29.4). At last follow-up, 71.6% of patients had good performance status (modified Rankin Scale score 0-2), and the rate of angiographic aneurysm occlusion was 90.2%.

CONCLUSIONS

This meta-analysis did not show a difference in overall complication rate between early versus delayed flow diversion for ruptured aneurysms. Early flow diversion for ruptured blister/fusiform/dissecting aneurysms carries a lower risk of aneurysm rerupture and overall complications as compared with that for ruptured saccular/giant aneurysms.

The use of flow diverters to treat small (≤5 mm) ruptured, saccular aneurysms

Background:

There is limited published literature on the use of flow diverting stents (FDS) to treat ruptured intracranial aneurysms in the acute stage. We present our experience of using FDS to treat small (≤5 mm) ruptured aneurysms.

Methods:

We retrospectively identified all patients with ≤5 mm ruptured aneurysms treated exclusively with FDS between February 2009 and February 2016. We recorded demographic data, the Hunt and Hess score, aneurysm location and size, therapeutic intervention, immediate angiographic and clinical result, and clinical and radiological follow-up information.

Results:

We identified seven patients (four females) with average age 59.8 ± 10 years (range 48–75). The average aneurysm fundus size was 2.7 ± 0.76 mm (range 1–4 mm). The average time from ictus to treatment was 6.3 days (range 1–14 days) and there were no cases of repeat rupture prior to treatment or intraoperative rupture. Angiographic follow-up was available in five patients. At initial follow-up, aneurysms (100%) were completely occluded raymond roy classification 1 (RRC 1). None of the aneurysms re-ruptured following treatment. Clinically, six patients were discharged with good functional outcome modified Rankin Score (mRS ≤2). There were no mortalities.

Conclusion:

The use of FDS to treat small, ruptured, saccular aneurysms is feasible; however, the use of FDS should not be considered first-line treatment. Further studies are required to determine the safety and efficacy of the use of FDS in the acute situation.

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.

Transient in-stent stenosis at mid-term angiographic follow-up in patients treated with SILK flow diverter stents: incidence, clinical significance and long-term follow-up

BACKGROUND

Little is known about in-stent stenosis (ISS) in patients with aneurysms treated with flow diverter (FD) stents. The reported incidence in the literature varies significantly.

OBJECTIVE

The aim of this study was to assess the incidence, severity, distribution, clinical significance, and possible predictors for ISS.

METHODS

Between July 2012 and June 2016 we retrospectively reviewed all patients treated with SILK FDs in our center. Only cases with short-term (4±2 months) and long-term (>1 year) follow-ups with digital subtraction angiograms were included. ISS was graded as mild (<25%), moderate (25-50%) or severe (>50%). The following predictors for ISS were assessed: gender, age, the presence of subarachnoid hemorrhage, aneurysm size, location, occlusion status, and post-stenting angioplasty.

RESULTS

Thirty-six patients met the inclusion criteria. At mid-term follow-up, ISS was observed in 16/36 patients (44%). Eleven patients (69%) had mild ISS, three (19%) moderate, and two (12%) severe ISS. ISS was diffuse in 11 patients (69%) and focal in five patients (31%). All patients were asymptomatic. Thirteen patients were maintained on dual antiplatelet therapy and three on aspirin alone. At long-term follow-up, complete ISS resolution was seen in 11 patients, improvement in three and worsening in two patients. No de novo ISS occurrence was observed. On univariate analysis there was no significant predictor for ISS.

CONCLUSIONS

Transient ISS after FD deployment is a common asymptomatic finding on mid-term angiographic follow-up. Complete resolution or improvement at long-term follow-up is seen in most patients who are maintained on dual antiplatelet therapy.

[Principles of surgical treatment for patients with asymptomatic aneurysms and cerebral aneurysms in the cold period after spontaneous intracranial hemorrhages]

Surgical treatment of patients with cerebral aneurysms still remains one of the most important issues of cerebrovascular neurosurgery, which is associated with both complexity of treatment and risks posed by the disease. The purpose of this publication is to discuss the recommendations and algorithms adopted at the Neurosurgical Institute for choosing surgical treatment of patients with single and multiple intracranial aneurysms based on the clinical course of disease and anatomical morphological classifications of aneurysms. The study was based on a large clinical material: we analyzed treatment outcomes in 1,621 patients (2009-2017); of these, 966 (59.5%) patients were operated on using microsurgical techniques, and 655 (40.4%) patients underwent endovascular surgery. Surgical treatment of patients with cerebral aneurysms has been performed in close cooperation between two vascular (microsurgical and endovasal) departments, using the latest technical innovations.

Acutely Ruptured Intracranial Aneurysms Treated with Flow-Diverter Stents: A Systematic Review and Meta-Analysis

BACKGROUND

The implantation of flow-diverter stents for the treatment of ruptured intracranial aneurysms required further investigation.

PURPOSE

Our aim was to analyze the outcomes after flow diversion of ruptured intracranial aneurysms.

DATA SOURCES

A systematic search of 3 databases was performed for studies published from 2006 to 2018.

STUDY SELECTION

According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we included studies (from 2010 to 2018) reporting acutely ruptured intracranial aneurysms treated with flow diversion.

DATA ANALYSIS

Random-effects meta-analysis was used to pool the following: aneurysm occlusion rate, complications, rebleeding, and factors influencing the studied outcomes.

DATA SYNTHESIS

We included 20 studies evaluating 223 patients with acutely ruptured intracranial aneurysms treated with flow-diverter stents. Immediate angiographic occlusion was obtained in 32% (29/86; 95% CI, 15.4%-48%; I² = 79.6%) of aneurysms, whereas long-term complete/near-complete aneurysm occlusion was 88.9% (162/189; 95% CI, 84%-93.5%; I² = 20.9%) (mean radiologic follow-up of 9.6 months). The treatment-related complication rate was 17.8% (42/223; 95% CI, 11%-24%; I² = 52.6%). Complications were higher in the posterior circulation (16/72 = 27%; 95% CI, 14%-40%; I² = 66% versus 18/149 = 11.7%; 95% CI, 7%-16%; I² = 0%) (P = .004) and after treatment with multiple stents (14/52 = 26%; 95% CI, 14%-45%; I² = 59%) compared with a single stent (20/141 = 10%; 95% CI, 5%-15%; I² = 0%) (P = .004). Aneurysm rebleeding after treatment was 4% (5/223; 95% CI, 1.8%-7%; I² = 0%) and was higher in the first 72 hours.

LIMITATIONS

Small and retrospective series.

CONCLUSIONS

Flow-diversion treatment of ruptured intracranial aneurysms yields a high rate of long-term angiographic occlusion with a relatively low rate of aneurysm rebleeding. However, treatment is associated with a complication rate of 18%. When coiling or microsurgical clipping are not feasible strategies, anterior circulation ruptured aneurysms can be effectively treated with a flow-diversion technique, minimizing the number of stents deployed. Given the 27% rate of complications, flow diversion for ruptured posterior circulation aneurysms should be considered only in selected cases not amenable to other treatments.

Treatment of Intracranial Aneurysms With the SILK Embolization Device in a Multicenter Study. A Retrospective Data Analysis

BACKGROUND

Flow-diverter technology has become an important stent-based embolization tool in the treatment of complex cerebrovascular pathology. We report here the experience of 4 Spanish centers with using the SILK flow-diverter (SFD) device.

OBJECTIVE

To evaluate the safety and efficacy of using the SFD in the endovascular treatment of intracranial aneurysms with complex morphology.

METHODS

We retrospectively examined a prospectively maintained database of patients treated with SFD devices between July 2008 and December 2013 at 1 of 4 institutions in Spain. Data regarding patient demographics, aneurysm characteristics, and technical procedure were analyzed. Angiographic and clinical findings were recorded during the procedure and at 12 months postoperatively.

RESULTS

A total of 175 SFD devices were implanted in 157 patients (women/men: 119/38; mean, median, and range of age: 56.2, 56.7, and 19-80 years, respectively), who were treated in a delayed manner (3-6 months from the event) for 180 aneurysms (165 unruptured and 15 ruptured). Adverse events (acute and delayed) were observed in 28.7% of cases (45/157), and most were resolved (19.1%; 30/157). Six months after the procedure, total morbidity and mortality were 9.6% (15/157) and 3.2% (5/157), respectively. Long-term imaging follow-up showed complete occlusion, neck remnants, and residual aneurysm in 78.1% (100/128), 14.0% (18/128), and 7.8% (10/128) of cases, respectively.

CONCLUSIONS

The SFD device is an effective tool for the treatment of challenging aneurysms, and allows complete occlusion within a year of the procedure in most patients, with morbidity and mortality comparable to those previously reported for similar devices.

Blood Flow Diversion as a Primary Treatment Method for Ruptured Brain Aneurysms-Concerns, Controversy, and Future Directions

Flow diversion is a novel treatment for brain aneurysms that works by redirecting blood flow away from the aneurysm. Immediately after placement of the stent, blood flow stagnates within the aneurysm dome and it undergoes thrombosis. Over time, a new endothelium develops across the neck, thereby reconstructing the parent vessel and curing the aneurysm. The use of this treatment method for ruptured aneurysms has two specific concerns: 1) risk of hemorrhage from the aneurysm after treatment because of potential delayed aneurysm occlusion; and 2) hemorrhagic complications from antiplatelet use, which is required to prevent thromboembolic complications from the device. In this review, we explore these two concerns based on the emerging published literature. Optimal peri-procedural management of these issues in the neurocritical care setting is vital to improving outcomes. We also identify ongoing clinical trials of flow diversion for the treatment of ruptured aneurysms. Flow diversion is an alternative to clipping or coiling for many ruptured aneurysms and may be potentially more efficacious in certain aneurysm subtypes.

Safety of Prasugrel loading in ruptured blister like aneurysm treated with a Pipeline device

OBJECTIVE

Blister like aneurysm (BLA) is extremely challenging to treat; endoluminal reconstruction has emerged as the most promising treatment method. When to treat after the ictus, the timing of administration of antiplatelet and causal relationship between platelet function testing results and thrombo-embolism is unclear. We theorized that Prasugrel with a lower incidence of resistance may be a safe suitable alternative to clopidogrel in patients treated with a flow diverter (FD).

METHODS

Prospectively collected data from consecutive patients treated for a ruptured blister with an FD was reviewed. Device deployment was timed to be at 2 h following Prasugrel loading. Thrombo-embolic and hemorrhagic complications, and occlusion rates were documented.

RESULTS

Nine patients were included. Most were females (55%); the median age was 55 (43, 65). The median Fischer grade was 3 (2, 4). A single pipeline device was deployed in all within 24 h of admission; the median time from ictus to device deployment was 4 days (2, 30). There were no thrombo-embolic or hemorrhagic complication. Complete occlusion was noted in 89% (n = 9).

CONCLUSION

Prasugrel loading timed 2 h prior to stent delivery did not increase thrombo-embolic or hemorrhagic complications. Single stent that is well apposed against the wall appears to be an effective treatment strategy to treat BLA. Advances in knowledge: Treatment of acutely ruptured BLA with a single pipeline device deployed at 2 h after Prasugrel loading appears to be safe.

Periprocedural safety of Pipeline therapy for unruptured cerebral aneurysms: Analysis of 279 Patients in a multihospital database

The relative safety of unruptured aneurysm treatment with coiling versus flow diversion therapy is unknown. Most data available on flow diversion reflect highly focused patient groups and very experienced operators. We evaluated a national, multihospital patient database to examine periprocedural morbidity and mortality in patients treated with endovascular flow diversion therapy. The Premier Perspective database was used to identify patients hospitalized between May 2011 and March 2013 for unruptured aneurysm who underwent flow diversion therapy with a Pipeline embolization device. The risk of in-hospital mortality and morbidity was determined using ICD 9 codes. A total of 279 unruptured aneurysm patients at 18 medical centers underwent endovascular therapy with a Pipeline device. Adverse outcomes included in-hospital mortality in two cases (0.7%), discharge to long-term care in 22 cases (7.9%), ischemic complications in 14 cases (5.0%), hemorrhagic complications in four cases (1.4%), and postoperative neurological complications in nine cases (3.2%). This study of a large cohort of patient hospitalizations in the United States provides preliminary data on flow diversion in a "real world" scenario and demonstrates that the periprocedural morbidity and mortality is not negligible and must be considered in the context of the natural history of the aneurysms that are being treated.

The Use of Flow Diverter in Ruptured, Dissecting Intracranial Aneurysms of the Posterior Circulation

OBJECTIVE

Acute dissecting aneurysms of the posterior circulation are a rare cause of subarachnoid hemorrhage. Established endovascular treatment options include parent artery occlusion and stent-assisted coiling, but appear to be associated with an increased risk of ischemic stroke. Vessel reconstruction with flow diverters is an alternative treatment option; however, its safety and efficacy in the acute stage remains unclear.

METHODS

This is a multicentric retrospective analysis of 15 consecutive acutely ruptured dissecting posterior circulation aneurysms treated with flow diverters. The primary end point was favorable aneurysm occlusion, defined as OKM C1-3 and D (O'Kelly Marotta scale). Secondary end points were procedure-related complications and clinical outcome.

RESULTS

Nine of 15 aneurysms (60%) arose from the intradural portion of the vertebral artery, 3 were located on the posterior inferior cerebellar artery and 1 each on the anterior inferior cerebellar artery, posterior cerebral artery, and basilar artery. Flow diverter placement was technically successful in 14 of 15 cases (93%). After endovascular treatment, none of the ruptured aneurysms rebled. Median clinical follow-up was 217 days and median angiographic follow-up was 203 days. Favorable occlusion was observed in 7 of 14 aneurysms (50%) directly after flow diverter placement; of those, 5 were completely occluded (36%). Seven patients (47%) with poor-grade subarachnoid hemorrhage died in the acute phase. Favorable clinical outcome (modified Rankin scale ≤2) was observed in 4 of 15 patients (27%) and a moderate outcome (modified Rankin scale 3/4) was observed in 5 of 15 patients (33%). All aneurysms showed complete occlusion at follow-up.

CONCLUSIONS

Flow diverters might be a feasible, alternative treatment option for acutely ruptured dissecting posterior circulation aneurysms and may effectively prevent rebleeding. Larger cohort studies are required to validate these results.

Stent-assisted coiling of cerebral aneurysms: a single-center clinical and angiographic analysis

Objective

This study retrospectively compared the clinical and angiographic outcomes of treating cerebral aneurysms with Neuroform (NEU), Enterprise (EP), and Low-profile Visualized Intraluminal Support (LVIS/LVIS Jr) stents.

Materials and methods

We conducted a retrospective analysis of a procedural database. All aneurysm procedures using any of the three types of self-expanding nitinol stents (NEU, EP and LVIS/LVIS Jr) were included. Intra-procedure complications, post-procedure complications, and angiographic results (Raymond–Roy grade scale, RRGS) were analyzed retrospectively. A multivariate logistic regression analysis was conducted to identify predictors of intra-procedure and post-procedure complications.

Results

Two hundred and forty-three aneurysms in 229 patients treated with stent-assisted coiling were included (NEU group: 109 aneurysms; EP group: 61 aneurysms; LVIS/LVIS Jr: 73 aneurysms). The LVIS/LVIS Jr group was associated with the lowest rate of initial complete occlusion (RRGS I: 47.9%; 35/73). Follow-up showed the proportion of RRGS I increased for all stent groups but was greatest in the LVIS/LVIS Jr group. Overall, 17 intra-procedural complications were seen in 229 patients (7.4%) and 15 post-procedural complications were found in 198 patients at follow-up (7.6%), with no differences between stent groups. Thrombotic events were the most common complications and occurred in 13 patients (13/229, 5.7%).

Conclusions

All three types of stents used to treat cerebral aneurysms with unfavorable neck were safe and effective, providing suitable support for the coil mass. LVIS/LVIS Jr promotes better progressive aneurysm complete occlusion than the other two stents but seems to cause more common intra-procedural stent-related thrombotic events and fewer post-procedural complications.

Clinical and angiographic outcomes in patients with intracranial aneurysms treated with the pipeline embolization device: intra-procedural technical difficulties, major morbidity, and neurological mortality decrease significantly with increased operator experience in device deployment and patient management

PURPOSE

Flow diversion constitutes a pivotal advancement in endovascular intracranial aneurysm treatment, but requires development of a new skill set. The aim of this study is to determine whether outcomes after treatment with the Pipeline Embolization Device improve with experience.

METHODS

We retrospectively reviewed all patients with intracranial aneurysms treated with Pipeline at two centers over a 4.5-year period. Baseline patient and aneurysm characteristics, complications, and angiographic outcomes were analyzed.

RESULTS

One hundred forty patients underwent 150 Pipeline procedures to treat 167 intracranial aneurysms during the study period, 109 women, mean age 55.4 years. One hundred twenty-six aneurysms were ICA, mean size 10.2 mm and mean neck 6.4 mm. Intra-procedural technical difficulties were higher during the first 75 procedures compared with the subsequent 75 (13.3 vs 2.7%; p = 0.03), as combined major morbidity and neurological mortality (14.7 vs 4%; p = 0.046). In multivariate regression analysis, increased operator experience with Pipeline remained an independent predictor of intra-procedural technical difficulties (p = 0.02, odds ratio (OR) 0.015, 95% CI 0.0004-0.55) and combined major morbidity and neurological mortality (p = 0.03, OR 0.16, 95% CI 0.03-0.84). At last follow-up, 123 aneurysms were completely occluded (81.5%, mean 24 months). In our cohort, age ≤ 53 years was an independent predictor of complete aneurysm occlusion at last follow-up (p = 0.001, OR 0.92, 95% CI 0.88-0.97). Five aneurysms were retreated (3.3%).

CONCLUSION

The Pipeline embolization device is an effective treatment for intracranial aneurysms. The risk of intra-procedural technical difficulties and combined major morbidity and neurological mortality decreases significantly with increased operator experience in Pipeline deployment and patient management.

Flow diversion with the pipeline embolization device for patients with intracranial aneurysms and antiplatelet therapy: A systematic literature review

Flow diversion with the Pipeline Embolization Device (PED) is reported as a safe and efficient treatment for patients with intracranial aneurysms; however, literature discussing the antiplatelet (APT) regimen used before and after the PED is limited. Our aim was to systematically review and summarize available data regarding the APT regimen and the platelet function test (PFT) that was used. We also sought to provide an overview of the aneurysm morphologies and adverse event rates associated with the PED use. This systematic review was conducted according to the PRISMA statement and eligible studies were identified through search of the PubMed and Cochrane databases. We reviewed 28 studies, involving 1556 patients that underwent aneurysm treatment with the PED. The preprocedural aspirin (ASA) 300- 325mg (2-14days) combined with clopidogrel 75mg (3 to >10days) were used as a treatment strategy in 61.7% of patients and ASA 81mg with clopidogrel 75mg for 5-10days for 27%. Patients who received low versus high dose pre-PED ASA, were at less risk for a hemorrhagic event (0.7% versus 3.3%, p=0.053); however no statistical significance was reached. There was also lack of relationship between patients that received low versus high preprocedural ASA in terms of thromboembolic events. Regarding postprocedural APT, ASA (>6months) and clopidogrel (3- 12 months) was the regimen of choice for 93% of patients. Most studies conducted at least one PFT, most common being the VerifyNow. The most frequently reported target P2Y12 Reaction unit (PRU) and Aspirin Reaction Unit (ARU) values were <230 and <550 respectively. There was no statistically demonstrable difference in regards to thrombotic events between centers that conducted at least one PFT and centers that did not test their patients with a PFT. The overall rates of symptomatic thrombotic episodes were 6.6% and hemorrhagic were 3%. The pre- and post-PED APT dose and duration varies across different institutions. More prospective studies are needed to compare the efficacy of different APT agents and reach conclusions regarding use of PFT and platelet reaction values in order to decrease hemorrhagic and thromboembolic complications associated with the PED.

Treatment of ruptured blood blister aneurysms using primary flow-diverter stenting with considerations for adjunctive coiling: A single-centre experience and literature review

Objective The objective of this article is to conduct a single-centre evaluation and quick literature review of the effectiveness of primary flow-diverter (FD) treatment of ruptured blood blister aneurysms (BBAs), with additional relevance of adjunctive coiling. Methods Patients presenting with subarachnoid haemorrhage (SAH) due to ruptured BBAs and subsequently treated with FDs were retrospectively selected from June 2010 to January 2017. Treatment techniques, angiographic data on occlusion rates and procedural success as well as clinical outcomes using the modified Rankin Scale (mRS) were collated. Cross-reference of results were made with available literature. Results Thirteen patients harbouring 14 BBAs were recruited. Of the 14 aneurysms, five (35.7%) showed immediate complete occlusion after the procedure (four of these five patients had adjunctive coiling). All of the aneurysms showed complete occlusion by the six- to nine-month control diagnostic angiogram. No rebleed or retreatment was experienced. Twelve of 13 (92%) patients had an mRS score of 0-1 at the last clinical follow-up. From the pooled data of the literature review, eventual aneurysm occlusion was achieved in 48/56 patients, with five patients requiring further endovascular treatment. In the clinical follow-up period, an mRS of 0-2 was recorded for 83.3% (45/54) of patients. Conclusion Endovascular reconstruction of BBAs using FD treatment is an effective method with good final clinical outcomes. Adjunctive use of coiling achieves higher incidence of immediate complete occlusion of BBAs.

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.

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.

A Case of Ruptured Blood Blister-like Aneurysm Treated with Pipeline Embolization Device: Clinical Significance of Fetal-type Posterior Communicating Artery

Blood-blister like aneurysms (BBAs) are challenging lesions because of their wide fragile neck. Flow-diverting stents (FDSs), such as the Pipeline Embolization Device (PED), have been applied to treat BBAs less amenable to more established techniques of treatment. However, the use of FDSs, including the PED, in acute subarachnoid hemorrhage (SAH) still remains controversial. We report a case of aneurysm regrowth following PED application for a ruptured BBA that overlapped the origin of the dominant posterior communicating artery (PCoA), which was successfully treated after coil trapping of the origin of the fetal-type PCoA. And, we discuss the clinical significance of the fetal-type PCoA communicating with a BBA in terms of PED failure.

Ophthalmic artery occlusion after Pipeline Embolization Device placement with reconstitution of flow via an endoleak: a report of two cases

The Pipeline Embolization Device (PED) is a flow diverting stent used in the treatment of a wide variety of intracranial aneurysms. The device differs from traditional stents used in stent-assisted coil embolization in that it has a tighter lattice structure with smaller cell sizes designed specifically to disrupt blood flow into aneurysms rather than only to retain coils within aneurysms. While the PED has been shown to be safe and effective, it has a unique risk profile that includes side branch and perforator vessel occlusion. Side branch occlusion in particular has been noted in several articles to occur at a relatively high rate with coverage of the ophthalmic artery origin by the PED. In this series, we present two cases of ophthalmic artery occlusion after PED placement with reconstitution of flow via an endoleak.

Flow Diversion in Ruptured Intracranial Aneurysms: A Meta-Analysis

BACKGROUND

Flow diversion is now an established technique to treat unruptured intracranial aneurysms not readily amenable to endovascular coil embolization or open microsurgical occlusion. The role of flow-diverting devices in treating ruptured aneurysms is less clear.

PURPOSE

To estimate rates of angiographic occlusion and good clinical outcome in patients with ruptured intracranial aneurysms treated with flow-diverting devices.

DATA SOURCES

Systematic review of Ovid MEDLINE, PubMed, Cochrane databases, and EMBASE from inception to December 2015 for articles that included ruptured aneurysms treated with flow diversion.

STUDY SELECTION

One hundred seventy-two records were screened, of which 20 articles contained sufficient patient and outcome data for inclusion.

DATA ANALYSIS

Clinical and radiologic characteristics, procedural details, and outcomes were extracted from these reports. Aggregated occlusion rates and clinical outcomes were analyzed by using the Fisher exact test (statistical significance, α = .05).

DATA SYNTHESIS

Complete occlusion of the aneurysm was achieved in 90% of patients, and favorable clinical outcome was attained in 81%. Aneurysm size greater than 7 mm was associated with less favorable clinical outcomes (P = .027). Aneurysm size greater than 2 cm was associated with a greater risk of rerupture after treatment (P < .001).

LIMITATIONS

Observational studies and case reports may be affected by reporting bias.

CONCLUSIONS

Although not recommended as a first-line treatment, the use of flow diverters to treat ruptured intracranial aneurysms may allow high rates of angiographic occlusion and good clinical outcome in carefully selected patients. Aneurysm size contributes to treatment risk because the rerupture rate following treatment is higher for aneurysms larger than 2 cm.

Quantitative flow measurement after placing a flow diverter for a distal internal carotid artery aneurysm

Objectives

To evaluate the differences in arterial flow after flow diverter placement using quantitative flow measurements based on digital subtraction angiography (DSA).

Methods

Between November 2013 and November 2015, all patients who had flow diverters placed for distal internal carotid artery (ICA) aneurysms were reviewed. Patients in whom the stent was placed across the ostia of the ophthalmic artery (OphA) and anterior choroidal artery (AChA) were enrolled. Five regions of interest were selected: the proximal ICA (as a reference), terminal ICA, middle cerebral artery (MCA), anterior cerebral artery (ACA), OphA, and AChA. The values of the peak, time-to-peak (TTP), and area under the curve (AUC) were analyzed using a quantitative DSA technique.

Results

The study enrolled 13 patients. The quantitative flow analysis showed improved flow in the terminal ICA (peak and AUC, p=0.036 and p=0.04, respectively), MCA (AUC, p=0.023), and ACA (AUC, p=0.006), and decreased flow in the OphA (peak and AUC, p=0.013 and p=0.005, respectively) and AChA (peak and subtracted TTP, p=0.023 and p=0.050, respectively) after flow diverter placement. Larger aneurysm volume was significantly correlated with decreased OphA flow after the procedure (peak and AUC, p=0.049 and p=0.037, respectively). Larger aneurysm volume also had a marginal correlation with increased distal ICA flow after the procedure, but this did not reach significance (peak and AUC, p=0.195 and p=0.060, respectively).

Conclusions

Without using extra contrast medium or radiation dosages, color-coded DSA enables quantitative monitoring of the cerebral circulation after flow-diverting treatment.

[Results of deconstructive endovascular surgery in treatment of large and giant intracranial aneurysms]

AIM

To clarify the indications for deconstructive endovascular surgery in patients with large and giant intracranial aneurysms and to evaluate short-term and long-term postoperative outcomes.

MATERIAL AND METHODS

The study was based on a retrospective analysis of the treatment results in 50 patients with large (15-25 mm) and giant (more than 25 mm) intracranial aneurysms, aged from 18 to 75 years, who were treated at the Burdenko Neurosurgical Institute in 2002-2014. The patients underwent a balloon occlusion test (BOT) in various modifications before stationary occlusion of the carrier artery. For vascular occlusion, we used detachable latex balloon catheters (33 cases) and microcoils (17 cases). The condition of patients in the pre- and postoperative period was assessed by using the modified Rankin Scale.

RESULTS

There were no deaths due to occlusion of the internal carotid artery (37 patients). Postoperative complications occurred in 5 patients. On the basis of BOT, revascularization surgery involving placement of an extra-intracranial microanastomosis (EICMA) was performed in 6 cases. In more 4 cases, EICMA was placed in the early postoperative period due to developing signs of ischemia. Two of 7 patients underwent occlusion of both vertebral arteries (VAs) in the vertebrobasilar basin, which led to fatal outcomes. One more patient died of aggravation of brainstem compression after VA occlusion. There was no worsening of neurological symptoms among survivors. There were no deaths and persistent neurological disorders upon occlusion of branches of the main cerebral arteries, starting with the first order arteries (6 patients). Thirty one patients (66%) were followed-up in the period from 1 to 104 months. There were no deaths associated with artery occlusion. Two patients experienced delayed ischemic disorders.

CONCLUSION

Occlusion of the carrier artery should be performed in a carefully selected group of BOT-negative patients. This surgery can be indicated for aneurysms with a complicated configuration, the topographic and anatomical features of which exclude reconstructive surgery.