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

Predictors of aneurysm occlusion after treatment with flow diverters: a systematic literature review

BACKGROUND

Flow diverters (FDs) have become an integral part of treatment for brain aneurysms.

AIM

To summarize available evidence of factors associated with aneurysm occlusion (AO) after treatment with a FD.

METHODS

References were identified using the Nested Knowledge AutoLit semi-automated review platform between January 1, 2008 and August 26, 2022. The review focuses on preprocedural and postprocedural factors associated with AO identified in logistic regression analysis. Studies were included if they met the inclusion criteria of study details (ie, study design, sample size, location, (pre)treatment aneurysm details). Evidence levels were classified by variability and significancy across studies (eg, low variability ≥5 studies and significance in ≥60% throughout reports).

RESULTS

Overall, 2.03% (95% CI 1.22 to 2.82; 24/1184) of screened studies met the inclusion criteria for predictors of AO based on logistic regression analysis. Predictors of AO with low variability in multivariable logistic regression analysis included aneurysm characteristics (aneurysm diameter), particularly complexity (absence of branch involvement) and younger patient age. Predictors of moderate evidence for AO included aneurysm characteristics (neck width), patient characteristics (absence of hypertension), procedural (adjunctive coiling) and post-deployment variables (longer follow-up; direct postprocedural satisfactory occlusion). Variables with a high variability in predicting AO following FD treatment were gender, FD as re-treatment strategy, and aneurysm morphology (eg, fusiform or blister).

CONCLUSION

Evidence of predictors for AO after FD treatment is sparse. Current literature suggests that absence of branch involvement, younger age, and aneurysm diameter have the highest impact on AO following FD treatment. Large studies investigating high-quality data with well-defined inclusion criteria are needed for greater insight into FD effectiveness.

Flow diversion of ruptured intracranial aneurysms: a single-center study with a standardized antithrombotic treatment protocol

BACKGROUND

The use of antithrombotic medication following acute flow diversion for a ruptured intracranial aneurysm (IA) is challenging with no current guidelines. We investigated the incidence of treatment-related complications and patient outcomes after flow diversion for a ruptured IA before and after the implementation of a standardized antithrombotic medication protocol.

METHODS

We conducted a single-center retrospective study including consecutive patients treated for acutely ruptured IAs with flow diversion during 2015-2023. We divided the patients into two groups: those treated before the implementation of the protocol (pre-protocol) and those treated after the implementation of the protocol (post-protocol). The primary outcomes were hemorrhagic and ischemic complications. A secondary outcome was clinical outcome using the modified Ranking Scale (mRS).

RESULTS

Totally 39 patients with 40 ruptured IAs were treated with flow diversion (69% pre-protocol, 31% post-protocol). The patient mean age was 55 years, 62% were female, 63% of aneurysms were in the posterior circulation, 92% of aneurysms were non-saccular, and 44% were in poor grade on admission. Treatment differences included the use of glycoprotein IIb/IIIa inhibitors (pre-group 48% vs. post-group 100%), and the use of early dual antiplatelets (pre-group 44% vs. 92% post-group). The incidence of ischemic complications was 37% and 42% and the incidence of hemorrhagic complications was 30% and 33% in the pre- and post-groups, respectively, with no between-group differences. There were three (11%) aneurysm re-ruptures in the pre-group and none in the post-group. There were no differences in mortality or mRS 0-2 between the groups at 6 months.

CONCLUSION

We found no major differences in the incidence of ischemic or hemorrhagic complications after the implementation of a standardized antithrombotic protocol for acute flow diversion for ruptured IAs. There is an urgent need for more evidence-based guidelines to optimize antithrombotic treatment after flow diversion in the setting of subarachnoid hemorrhage.

Perioperative and long-term complications following therapeutic internal carotid artery occlusion

BACKGROUND

Parent artery occlusion (PAO) is an effective treatment for hemorrhagic diseases associated with the internal carotid artery. There are several reports of long-term cerebral infarction or the formation of de novo cerebral aneurysms following PAO.

MATERIALS AND METHODS

We retrospectively reviewed these complications in 38 patients who underwent PAO for therapeutic treatment. We investigated perioperative cerebral infarctions, long-term cerebral infarctions, and de novo aneurysms.

RESULTS

The mean age of the patients was 64.0 years, and 25 patients (65.8%) were female. The causative diseases were unruptured (n = 19; 50.0%) and ruptured (n = 8; 21.1%) aneurysms. PAO was performed after ischemic tolerance was assessed with balloon test occlusion (BTO), and BTO was performed in 34 patients, of whom 25 (73.5%) had ischemic tolerance. Twenty-six patients (68.4%) were treated with PAO alone, eight (23.5%) with low-flow bypass, and six (17.6%) with high-flow bypass. Perioperative complications occurred in five patients (13.2%): two of the 26 patients (7.7%) who underwent scheduled treatment and three of the 12 patients (25.0%) who underwent emergency treatment. One patient (2.6%) had long-term de novo aneurysm, and none developed cerebral infarction.

CONCLUSIONS

These results showed that the assessment of ischemic tolerance by performing BTO and appropriate revascularization in scheduled treatments are important to reduce perioperative and long-term cerebral infarctions. PAO must be performed with greater caution in emergency treatment.

Flow Diversion for the Management of Ruptured Intracranial Arterial Infudibular Dilatation: Proof of Principle and Therapeutic Protocol

Thought to be benign anatomical variants, cerebral infundibular dilatations (ID) are most commonly encountered at the junction of the internal carotid artery (ICA) and the posterior communicating artery (PcomA). The true nature of this entity remains controversial, as some literature reports suggest they should be considered preaneurysmal lesions and a potential source of devastating subarachnoid hemorrhage. This report describes cases of presumably ruptured IDs and their therapeutic endovascular management. We retrospectively reviewed and analyzed patients with isolated subarachnoid hemorrhage (SAH) where the only potential cause was ruptured cerebral IDs, treated or not, between January 2012 and June 2021. Morphological and radiological features, treatment and procedural considerations, clinical and angiographic outcomes were also reviewed. Natural history of the ID is poorly understood, and its relation to SAH remains controversial. Ruptured cerebral IDs can be the suspected cause of bleeding if no other vascular lesion is present during multimodal examinations. Endovascular flow diversion stenting is safe and effective for the proper treatment of ruptured IDs. Pending further validations with longitudinal data are needed to legitimate the natural course of these mysterious lesions.

Comaneci plus Balloon-assisted Embolization of Ruptured Wide-necked Cerebral Aneurysms

BACKGROUND AND PURPOSE

Recently, avant-garde combinations of ancillary devices as an adjunct to coil embolization for acutely ruptured and wide-necked cerebral aneurysms have emerged. This study sought to investigate the feasibility, safety and durability of the simultaneous combination of temporary neck-bridging devices plus balloon-assisted coiling (BAC) to treat acutely ruptured and wide-necked cerebral aneurysms.

METHODS

A retrospective review was performed of patients with ruptured and wide-necked intracranial bifurcation aneurysms treated with temporary stent plus balloon-assisted coiling. Anatomical features, technical details, intraprocedural complications, clinical and angiographic results were reviewed. Preprocedural and follow-up clinical statuses were evaluated using the modified Rankin scale (mRS).

RESULTS

A total of 21 patients (mean age 54.5 years, range 37-72 years) were identified. The immediate postprocedural angiography revealed complete aneurysm occlusion in 85.7% (18/21) of the cases. A periprocedural complication developed in 9.5% of the cases. There was no mortality in this study. The permanent morbidity rate was 4.7%. Long-term follow-up angiography was performed in 18 of 21 patients (85.7%) (the mean follow-up period was 21 months). The rate of complete aneurysm occlusion at final follow-up was 89.4%.

CONCLUSION

The results of this study confirmed that temporary stent plus balloon-assisted coiling is a durable and relatively safe endovascular technique for the treatment of ruptured wide-necked bifurcation aneurysms located in both the posterior and anterior cerebral circulation.

Flow-diverter stents in the early management of acutely ruptured brain aneurysms: effective rebleeding protection with low thromboembolic complications

OBJECTIVE

Flow-diverter stents (FDSs) are not generally used for the management of acutely ruptured aneurysms with associated subarachnoid hemorrhage (SAH). Herein, the authors present their experience with FDSs in this scenario, focusing on the antiplatelet regimen, perioperative management, and outcome.

METHODS

The authors retrospectively reviewed their institutional database for the treatment and outcomes of all patients with acutely ruptured aneurysms and associated SAH from July 2010 to September 2018 who had received an FDS implant as stand-alone treatment within 4 days after diagnosis. The protocol with the use of flow diversion in these patients includes a low threshold for placement of external ventricular drains before stenting, followed by the administration of aspirin and clopidogrel with platelet testing before stent implantation. With this approach, the risk of hemorrhage and stent-related thrombus formation is limited. Demographic, clinical, technical, and imaging data were analyzed.

RESULTS

Overall, 76 patients (61% females, mean age 42.8 ± 11.3 years) met the inclusion criteria. FDS implantation was performed a median of 2 days after diagnosis. On average, 1.05 devices were used per procedure. There was no procedural mortality directly attributed to the endovascular intervention. Procedural device-related clinical complications were recorded in a total of 6 cases (7.9%) and resulted in permanent neurological morbidity in 2 cases (2.6%). There was complete immediate aneurysm occlusion in 11 patients (14.5%), and persistent aneurysm filling was seen in 65 patients (85.5%). Despite this, no patient presented with rebleeding from the target aneurysm. There was an excellent clinical outcome in 62 patients (81.6%), who had a 90-day modified Rankin Scale score of 0-2. Among the 71 survivors, total or near-total occlusion was observed in 64/67 patients (95.5%) with a 3- to 6-month angiographic follow-up and in all cases evaluated at 12 months. Five patients (6.6%) died during follow-up for reasons unrelated to the procedure or new hemorrhage.

CONCLUSIONS

Flow diversion is an effective therapeutic strategy for the management of select acutely ruptured aneurysms. Despite low rates of immediate aneurysm occlusion after FDS implantation, the device exerts an important protective effect. The authors' experience confirmed no aneurysm rerupture, high rates of delayed complete occlusion, and complication rates that compare favorably with the rates obtained using other techniques.

Treatment of acute aneurysmal subarachnoid haemorrhage with primary flow diversion: 5-year single-centre experience

AIM

To evaluate the safety and efficacy of treatment of patients presenting with acute aneurysmal subarachnoid haemorrhage (SAH) with primary flow-diverting stents (FDS; with or without adjuncts), with comparison to the published literature.

MATERIALS AND METHODS

A retrospective single-centre review was undertaken of prospectively obtained data on patients treated for SAH over a 60-month period. Of 354 patients treated for SAH during that time period, 24 patients with a total of 25 aneurysms were identified. Baseline patient demographics were recorded and clinical and imaging outcomes assessed.

RESULTS

Eighty-eight per cent (22/25) of the aneurysms were completely occluded (Raymond-Roy 1) at mean 12-month follow-up. The minor complication rate was 12.5% (3/24) without permanent morbidity. Mortality rate was 4% (1/25) after one patient died following aneurysmal rebleed on day 7 post-procedure. Forty-two per cent (10/24) of patients had a high-pressure shunt placed prior to endovascular treatment, no haemorrhagic complications of neurosurgical intervention were observed.

CONCLUSION

The necessity of dual antiplatelet therapy (DAPT) therapy when deploying FDS will rightly continue to limit their use in the acutely ruptured setting to a case-by-case basis whereby other treatment options are deemed unsafe. Methods employed to minimise subsequent haemorrhagic risks from DAPT in these patients may be worthy of further investigation.

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.

Aneurysm Treatment in Acute SAH with Hydrophilic-Coated Flow Diverters under Single-Antiplatelet Therapy: A 3-Center Experience

BACKGROUND AND PURPOSE

In certain clinical circumstances, dual-antiplatelet therapy can be problematic in patients with acute SAH. In some aneurysms, however, flow-diverting stents are the ideal therapeutic option. We report our experience with ruptured intracranial aneurysms treated with flow diverters with hydrophilic coating (p48 MW HPC and p64 MW HPC) under single-antiplatelet therapy.

MATERIALS AND METHODS

Patients were treated with either flow-diverter placement alone or a flow diverter and additional coiling. Due to the severity of the hemorrhage, the potential for periprocedural rehemorrhage, and the potential for additional surgical interventions, a single-antiplatelet regimen was used in all patients.

RESULTS

Thirteen aneurysms were treated in 10 patients. The median age was 62 years; 5 patients were male. All had acute SAH due to aneurysm rupture. Four blood-blister, 2 dissecting, and 7 berrylike aneurysms were treated. Seven aneurysms were adjunctively coiled. Eight of the 10 patients received a single-antiplatelet protocol of aspirin, 1 patient was treated with prasugrel only, and 1 patient was treated with tirofiban first and then switched to the aspirin single-antiplatelet protocol. One device-related complication occurred, a thrombosis of an overstented branch. All stents, however, remained open at DSA, CTA, or MRA follow-up.

CONCLUSIONS

The implantation of flow diverters with reduced thrombogenicity due to hydrophilic surface coating under single-antiplatelet therapy seems to be an option in carefully selected cases of SAH due to aneurysm rupture.

Comaneci-Assisted Coiling as a Treatment Option for Acutely Ruptured Wide Neck Cerebral Aneurysm: Case Series of 118 Patients

BACKGROUND

Wide-necked cerebral aneurysms in the setting of acute subarachnoid hemorrhage (SAH) remain difficult to treat with endovascular methods despite recent progress in the neuroendovascular field.

OBJECTIVE

To evaluate the effectiveness and safety of the Comaneci device (Rapid Medical, Israel) in endovascular coil embolization of acutely ruptured, wide-necked sidewall, or bifurcation cerebral aneurysms.

METHODS

We retrospectively reviewed 45 anterior communicating artery, 24 internal carotid artery, 21 middle cerebral artery bifurcation, 15 anterior cerebral artery, and 13 posterior circulation aneurysms, which were treated using Comaneci-assisted coil embolization from August 2017 to January 2019. We evaluated procedural complications, clinical outcomes, and mid-term angiographic follow-up. Immediate and 90 d-clinical outcome and radiological follow-up were obtained in all patients.

RESULTS

Comaneci-assisted coil embolization was performed in 118 acutely ruptured aneurysms. The technique was carried out successfully in all cases. Simultaneous application of 2 separated Comaneci devices was performed in 8/118 cases (6.77%). Periprocedural thromboembolic complications related to the device were seen in 7/118 cases (5.93%) and severe vasospasm of the parent artery after manipulation of the Comaneci device occurred in 5/118 cases (4.2%). The procedural-related morbidity rate was 2.54%, and there was no procedural related mortality. Among the available survivors, angiographic follow-ups were obtained at 3 and 6 mo, and complete aneurysmal obliteration was confirmed in 81/112 (72.3%) and 75/112 (66.9%) cases, respectively. Mid-term follow-up reviewed total recanalization rate of 14.28%.

CONCLUSION

Comaneci-assisted embolization of wide-necked intracranial aneurysms in patients presenting with acute SAH is associated with high procedural safety and adequate occlusion rates. Furthermore, dual antiplatelet therapy can be safely avoided in this patient group.

The Cascade device - In vitro tests to assess coil protrusion into the parent vessel

BACKGROUND

Balloon and stent-assisted coiling of aneurysms have increased the number of aneurysms available for endovascular treatment. Newer devices that allow flow within the parent vessel but coverage at the neck have recently entered the market. The Cascade is a new non-occlusive fully retrievable neck-bridging support device that has been designed to provide temporary support during coil embolisation of intracranial aneurysms.

METHODS

Using a silicone aneurysm model three different aneurysms were catheterised with the coiling microcatheter placed in three different positions within each aneurysm - at the neck, centrally, and looped within the aneurysm. Multiple different coils were then deployed within each aneurysm with the Cascade device deployed across the neck to provide protection. In total 480 attempted coilings were performed. Aneurysm flow was used to calculate the change in intra-aneurysmal flow with the Cascade device deployed across the neck of the aneurysm.

RESULTS

We did not observe a single episode of coil protrusion through the Cascade mesh nor did we observe any coil protrusion into the parent vessel when the Cascade was deployed across the neck. There was an average flow velocity reduction of 23% with the Cascade device deployed across the neck of the aneurysm.

CONCLUSION

The Cascade device offers robust protection of the aneurysmal neck and parent vessel as well as inducing significant intra-aneurysmal flow velocity reduction.

Thrombogenicity of the p48 and anti-thrombogenic p48 hydrophilic polymer coating low-profile flow diverters in an in vitro human thrombin generation model

OBJECTIVES

The implantation of flow diverters, or stents in general, necessitates the use of dual anti-platelet treatment with typical regimes including aspirin and a P2Y12 inhibitor. This carries an inherent risk of haemorrhage. We sought to compare the thrombogenicity of the anti-thrombogenic p48 hydrophilic polymer coating compared to the standard uncoated p48 flow diverter using an in vitro thrombogenicity assay.

METHODS

To evaluate the thrombin generation influenced by the different stent types the stents were placed in wells of a 24-well plate with the addition of plasma from healthy volunteers the thrombin calibrator respectively the PPP-reagent was added. Subsequently, the thrombin substrate was added and the thrombin generation was analysed every 60 s using a thrombinoscope. The assay is calibrated using samples containing a known amount of active thrombin in PPP. Thrombin activity is proportional to the change in fluorescence.

RESULTS

The p48 hydrophilic polymer coating shows a significantly lower peak thrombin concentration (1.13 ± 0.21 vs. 1.41 ± 0.22) and longer time to peak thrombin concentration (0.96 ± 0.04 vs. 0.74 ± 0.07) compared to the uncoated p48 device (p < 0.01). The responses of the p48 hydrophilic polymer coating were similar to that of the negative control.

CONCLUSION

The hydrophilic polymer coating surface modification significantly reduces the thrombogenicity of the p48 flow diverter. These results corroborate the findings from previous in vitro studies.