Mechanical thrombectomy is efficacious in patients with pre-stroke moderate disability.

INTRODUCTION: Patients with ischaemic stroke due to large vessel occlusion (LVO) can be treated successfully with mechanical thrombectomy (MT) and/or intravenous thrombolysis. In the landmark trials, MT was only performed for those with no functional disability prior to stroke (mRS 0-2). There are limited data available regarding clinical outcomes for patients with pre-stroke moderate disability (mRS ≥ 3). The aims of this study were to analyse the clinical outcomes and financial implications in regard to accommodation costs of performing MT in patients with pre-stroke mRS = 3. METHODS: An observational cohort study was performed of 802 patients with anterior circulation LVO ischaemic stroke who underwent MT between October 2016 and January 2020 at three tertiary hospitals. Patient demographics, premorbid mRS, stroke and interventional data, 90-day mRS and accommodation situation were recorded. RESULTS: Eighty-two patients with anterior circulation LVO ischaemic stroke were pre-stroke mRS 3. 38% had a good clinical outcome, as defined by mRS 3 at 90 days. Mortality rate was 38%. The majority of patients presented from home (83%) and greater than one third of those returned home during the 90 days post treatment. 81% of patients had no increase in accommodation cost at 90 days. CONCLUSION: Patients with pre-stroke moderate disability may benefit from MT if they are appropriately selected. This may result in fewer patients requiring nursing home placement and less financial burden on the public health system, indicating significant savings are possible.

Transradial versus transfemoral access for anterior circulation mechanical thrombectomy: analysis of 375 consecutive cases.

OBJECTIVE: To compare transradial artery access (TRA) to the gold standard of transfemoral artery access (TFA) in mechanical thrombectomy (MT) for stroke caused by anterior circulation large vessel occlusion. METHODS: The clinical outcomes, procedural speed, angiographic efficacy and safety of both techniques were analysed in 375 consecutive cases over an 18-month period in a high volume statewide neurointerventional service. RESULTS: There was no significant difference in patient characteristics, stroke parameters, imaging techniques or intracranial techniques. The median time elapsed between CT scanning and reperfusion was 96.5 min (IQR 68-123) in the TFA group and 95 min (IQR 68-123) in the TRA group (p=0.456). Of 336 patients who were independent at presentation 58% (124/214) of the TFA group and 67% (82/122) of the TRA group had a modified Rankin score of 0-2 at 90-day follow-up (p=0.093). Cross-over from radial to femoral was 4.6% (4/130) compared with 1.6% cross-over from femoral to radial (4/245), but did not meet the predetermined level of statistical significance (OR 2.92, 95% CI 0.81 to 10.52), p=0.088) and did not impact median procedural speed. Adequate angiographic reperfusion, first pass reperfusion, embolisation to new territory and symptomatic intracranial haemorrhage were similar in both groups. There was a significant difference in major access site complications requiring an additional procedure. None of the TRA cases had a major access site complication but 6.5% (16/245) of the TFA cases did (p=0.003). CONCLUSION: This study suggests that using TRA for anterior circulation MT is fast, efficacious, safe and not inferior to the gold standard of TFA.

Future Directions of Flow Diverter Therapy.

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

Dual suction Headway27 microcatheter thrombectomy for the treatment of distal intracranial arterial occlusion strokes: initial experience with the micro-ADAPT technique.

BACKGROUND: Recent studies suggest that the proven benefits of endovascular thrombectomy (EVT) for the treatment of large vessel occlusion (LVO) strokes are transferable to more peripheral distal vessel occlusion (DVO) strokes under certain circumstances. Safely accessing and extracting these thrombi however remains challenging, particularly in more tortuous peripheral arteries. For such cases we have utilized the dual suction Headway27 microcatheter thrombectomy, or micro-ADAPT, technique with the aim of reducing potential trauma associated with negotiating stent retrievers or large bore aspiration catheters into the peripheral intracranial vasculature. We present our experience utilizing the micro-ADAPT in the treatment of DVO strokes. We describe our technique as well as present angiographic and clinical outcomes. METHODS: A retrospective review of our institution's prospectively collected EVT registry for the 12 months spanning July 2017 to June 2018 was undertaken. Data on all cases of micro-ADAPT EVT were collected and analyzed. RESULTS: Micro-ADAPT EVT was performed 14 times over the study period, with a recanalization rate of 79%. DVO strokes in multiple locations were treated, including the A3, M3, P3, and superior cerebellar artery. In cases where an LVO stroke was also present, the mean duration between primary LVO recanalization and secondary DVO micro-ADAPT recanalization was 15.5 min. No complications relating to the micro-ADAPT technique were recorded. No infarcts were present in the territory of the recanalized DVO stroke on day 1 CT in successful micro-ADAPT cases CONCLUSIONS: In the setting of challenging peripheral DVO strokes, the micro-ADAPT technique appears to be a fast and effective technique with a low complication rate.

Direct endovascular thrombectomy and bridging strategies for acute ischemic stroke: a network meta-analysis.

OBJECTIVES: The present Bayesian network meta-analysis aimed to compare the various strategies for acute ischemic stroke: direct endovascular thrombectomy within the thrombolysis window in patients with no contraindications to thrombolysis (DEVT); (2) direct endovascular thrombectomy secondary to contraindications to thrombolysis (DEVTc); (3) endovascular thrombectomy in addition to thrombolysis (IVEVT); and (4) thrombolysis without thrombectomy (IVT). METHODS: Six electronic databases were searched from their dates of inception to May 2017 to identify randomized controlled trials (RCTs) comparing IVT versus IVEVT, and prospective registry studies comparing IVEVT versus DEVT or IVEVT versus DEVTc. Network meta-analyses were performed using ORs and 95% CIs as the summary statistic. RESULTS: We identified 12 studies (5 RCTs, 7 prospective cohort) with a total of 3161 patients for analysis. There was no significant difference in good functional outcome at 90 days (modified Rankin Scale score ≤2) between DEVT and IVEVT. There was no significant difference in mortality between all treatment groups. DEVT was associated with a 49% reduction in intracranial hemorrhage (ICH) compared with IVEVT (OR 0.51; 95% CI 0.33 to 0.79), due to reduction in rates of asymptomatic ICH (OR 0.47; 95% CI 0.29 to 0.76). Patients treated with DEVT had higher rates of reperfusion compared with IVEVT (OR 1.73; 95% CI 1.04 to 2.94). CONCLUSIONS: To our knowledge, this is the first network meta-analysis to be performed in the era of contemporary mechanical thrombectomy comparing DEVT and DEVTc. Our analysis suggests the addition of thrombolysis prior to thrombectomy for large vessel occlusions may not be associated with improved outcomes.

Transvenous coil embolization with intra-operative cone beam CT assistance in the treatment of hypoglossal canal dural arteriovenous fistulae.

BACKGROUND: Hypoglossal canal dural arteriovenous fistulae (HC-dAVF) are a rare subtype of skull base fistulae involving the anterior condylar confluence or anterior condular vein within the hypoglossal canal. Transvenous coil embolization is a preferred treatment strategy, however delineation of fistula angio-architecture during workup and localization of microcatheter tip during embolization remain challenging on planar DSA. For this reason, our group have utilized intra-operative cone beam CT (CBCT) and selective cone beam CT angiography (sCBCTA) as adjuncts to planar DSA during workup and treatment. The purpose of this article is to present our experience in the treatment of HC-dAVF using transvenous coil embolization (TVCE) with cone beam CT assistance, describing our technique as well as presenting our angiographic and clinical outcomes. METHODS: Ten patients with symptomatic HC-dAVF were treated using TVCE with intra-operative cone beam CT assistance. Prospectively collected data regarding clinical and angiographic results and complication rates was recorded and reviewed. RESULTS: Complication-free fistula occlusion was achieved in our entire patient cohort. The dominant symptom of pulsatile tinnitus resolved in all 10 patients. CONCLUSIONS: This study demonstrates that TVCE with CBCT assistance is a highly effective treatment option for HC-dAVF, achieving complication-free fistula occlusion in our entire patient cohort. We have found low-dose sCBCTA and CBCT to be an extremely useful adjunct to planar DSA imaging during both workup and treatment of these rare fistulae.

Use of aspirin as sole oral antiplatelet therapy in acute flow diversion for ruptured dissecting aneurysms.

Subarachnoid hemorrhage secondary to rupture of a circumferential dissecting aneurysm continues to be a treatment dilemma. Vessel sacrifice, when possible, continues to be the safest option but in certain cases this is not possible due to lack of collateral supply. In such cases, coil assisted endovascular flow diversion has become a potential option but the requirement for dual antiplatelet therapy in an unsecured intracranial aneurysm continues to raise concern.We present a 48-year-old man with a World Federation of Neurological Surgeons grade 5 subarachnoid hemorrhage, secondary to a ruptured intradural left vertebral artery dissecting aneurysm, who was treated successfully with a pipeline embolization device with Shield technology using aspirin and a single intravenous loading dose of abciximab. To our knowledge, this is the first case of an acute flow diversion performed using only aspirin as the sole oral antiplatelet agent.

Use of aspirin as sole oral antiplatelet therapy in acute flow diversion for ruptured dissecting aneurysms.

Subarachnoid hemorrhage secondary to rupture of a circumferential dissecting aneurysm continues to be a treatment dilemma. Vessel sacrifice, when possible, continues to be the safest option but in certain cases this is not possible due to lack of collateral supply. In such cases, coil assisted endovascular flow diversion has become a potential option but the requirement for dual antiplatelet therapy in an unsecured intracranial aneurysm continues to raise concern.We present a 48-year-old man with a World Federation of Neurological Surgeons grade 5 subarachnoid hemorrhage, secondary to a ruptured intradural left vertebral artery dissecting aneurysm, who was treated successfully with a pipeline embolization device with Shield technology using aspirin and a single intravenous loading dose of abciximab. To our knowledge, this is the first case of an acute flow diversion performed using only aspirin as the sole oral antiplatelet agent.

Pipeline embolization device induced collateral channels in elective flow diversion treatment.

The pipeline embolization device (PED) is a well recognized treatment for intracranial aneurysms. However, uncertainty remains regarding its effects on flow alteration, which is particularly highlighted by persistently perfused aneurysmal remnants and non-regressing, non-perfused aneurysmal masses. Here we present a 68-year-old woman with an incidental giant fusiform right paraophthalmic aneurysm electively treated with a PED. After lowering her antiplatelet therapy to promote aneurysm thrombosis, she was found to have a progressively enlarging perfused aneurysmal remnant. Angiography revealed PED occlusion, but curiously the development of a peri-construct collateral channel which feeds the aneurysmal remnant, and gives rise to distal branches and contributes to middle cerebral artery flow. The large 'thrombosed' aneurysmal mass showed tiny internal vessels on cone beam CT angiography as well as florid enhancement on MRI, further confirming that apparently thrombosed remnants are biologically active and may be remodeled depending on flow demand.

Pipeline embolization device induced collateral channels in elective flow diversion treatment.

The pipeline embolization device (PED) is a well recognized treatment for intracranial aneurysms. However, uncertainty remains regarding its effects on flow alteration, which is particularly highlighted by persistently perfused aneurysmal remnants and non-regressing, non-perfused aneurysmal masses. Here we present a 68-year-old woman with an incidental giant fusiform right paraophthalmic aneurysm electively treated with a PED. After lowering her antiplatelet therapy to promote aneurysm thrombosis, she was found to have a progressively enlarging perfused aneurysmal remnant. Angiography revealed PED occlusion, but curiously the development of a peri-construct collateral channel which feeds the aneurysmal remnant, and gives rise to distal branches and contributes to middle cerebral artery flow. The large 'thrombosed' aneurysmal mass showed tiny internal vessels on cone beam CT angiography as well as florid enhancement on MRI, further confirming that apparently thrombosed remnants are biologically active and may be remodeled depending on flow demand.

Pipeline embolization device thrombosis induced peri-construct collateral channels.

More than half a decade of experience and follow-up has now been accumulated with regard to flow diversion as a treatment for intracranial aneurysms; however, many uncertainties, such as the nature of aneurysmal remnants and the meaning of non-regressed, non-perfused aneurysmal masses, are still unknown. Here we discuss a 22-year-old man who presented with a grade 1 subarachnoid hemorrhage secondary to a dissecting right anterior cerebral artery aneurysm who was subsequently treated with a Pipeline Embolization Device construct. After ceasing dual antiplatelet therapy himself, he was found on MRI to have an area of increased aneurysmal remnant reperfusion. This was found to connect to multiple channels which reconstituted flow within the distal construct on angiography. The central area of construct thrombosis could not be visualized on MRI. The finding suggests that non-opacified aneurysmal remnants that have not regressed are biologically active and raises concerns regarding using MRI for long term follow-up.

Pipeline embolization device thrombosis induced peri-construct collateral channels.

More than half a decade of experience and follow-up has now been accumulated with regard to flow diversion as a treatment for intracranial aneurysms; however, many uncertainties, such as the nature of aneurysmal remnants and the meaning of non-regressed, non-perfused aneurysmal masses, are still unknown. Here we discuss a 22-year-old man who presented with a grade 1 subarachnoid hemorrhage secondary to a dissecting right anterior cerebral artery aneurysm who was subsequently treated with a Pipeline Embolization Device construct. After ceasing dual antiplatelet therapy himself, he was found on MRI to have an area of increased aneurysmal remnant reperfusion. This was found to connect to multiple channels which reconstituted flow within the distal construct on angiography. The central area of construct thrombosis could not be visualized on MRI. The finding suggests that non-opacified aneurysmal remnants that have not regressed are biologically active and raises concerns regarding using MRI for long term follow-up.

Propofol as a substitute for amobarbital in Wada testing.

We describe a patient with equivocal findings on functional MRI (fMRI), who underwent a propofol Wada test, review the literature on this topic and suggest a protocol for the use of propofol for a Wada test. Although fMRI techniques can usually accurately lateralize language, the Wada test remains the gold standard for preoperative lateralization and is occasionally still required if there are non-diagnostic findings on fMRI. Amobarbital, the agent of choice for the Wada test, has become increasingly difficult to obtain and requires regulatory approval, which may delay definitive management and have an impact on patient outcomes. Propofol has been suggested as an alternative to amobarbital, and while there is some published data on this, there is no reported Australian experience to date.

Double-lumen arterial balloon catheter technique for Onyx embolization of dural arteriovenous fistulas: initial experience.

BACKGROUND: Dural arteriovenous fistulas are vascular malformations with variable clinical symptoms that range in severity from completely asymptomatic to seizures, dementia, loss of vision and intracranial hemorrhage. Historically, surgical obliteration was the treatment of choice but, more recently, endovascular embolization has become the first-line treatment. The liquid embolic agent Onyx (ethyl vinyl copolymer) has become the agent of choice, but problems with reflux around the delivery microcatheter and inadvertent venous penetration have arisen. METHODS AND RESULTS: We present six cases in which the double-lumen balloon microcatheter was used to transarterially embolize dural arteriovenous fistulas via injection of Onyx through the wire lumen. Depending on the individual pathology a venous balloon was also used in some cases. The advantages and disadvantages of the use of these devices are discussed. CONCLUSIONS: We consider that the use of the double-lumen balloon technique for fistula embolization has the potential for reducing overall procedural times, procedural failures and catheter retention in certain situations. In such cases we would advocate this as a first-line technique. When lower profile, more navigable balloon catheters become available, this may become the standard of care.

De novo cavernoma developing from an asymptomatic thalamic microhemorrhage.

Cavernomas are low-flow vascular lesions affecting approximately 0.5% of the population. Historically these have been considered congenital lesions, but numerous reports have demonstrated de novo formation. The phenomenon is well documented in patients with the familial disease form and after cranial radiotherapy, but outside of these circumstances there is scant evidence as to the potential etiology. The authors present a 5 year MRI series of a 56-year-old woman with no known risk factors demonstrating cavernoma formation and growth from previously normal brain. The patient was consistently asymptomatic during follow-up. Given the history and imaging findings, we propose that cavernomas can arise directly from angiogenic proliferation secondary to microhemorrhage from unrelated causes.

Cerebral hyperperfusion after flow diversion of large intracranial aneurysms.

Cerebral hyperperfusion syndrome has been proposed to be caused by rapidly increased blood flow into chronically hypoperfused parenchyma with resultant impaired autoregulation, and has been noted after clipping of intracranial aneurysms and carotid stenting. The occurrence of the syndrome after endovascular flow diversion, however, has not been previously described. A 52-year-old woman was admitted electively for flow diverter treatment of a recurrent ventral paraclinoid aneurysm arising within a dysplastic segment of the left internal carotid artery. During the immediate postprocedural period the patient was found to have confusion, right hemiparesis, facial droop and dysarthria, which resolved with blood pressure control. Subsequent CT perfusion on day 11 demonstrated mildly elevated cerebral blood flow, cerebral blood volume and permeability values in the left hemisphere.

Cerebral hyperperfusion after flow diversion of large intracranial aneurysms.

Cerebral hyperperfusion syndrome has been proposed to be caused by rapidly increased blood flow into chronically hypoperfused parenchyma with resultant impaired autoregulation, and has been noted after clipping of intracranial aneurysms and carotid stenting. The occurrence of the syndrome after endovascular flow diversion, however, has not been previously described. A 52-year-old woman was admitted electively for flow diverter treatment of a recurrent ventral paraclinoid aneurysm arising within a dysplastic segment of the left internal carotid artery. During the immediate postprocedural period the patient was found to have confusion, right hemiparesis, facial droop and dysarthria, which resolved with blood pressure control. Subsequent CT perfusion on day 11 demonstrated mildly elevated cerebral blood flow, cerebral blood volume and permeability values in the left hemisphere.