Endovascular Management of Brain Arteriovenous Malformations.

Due to the risk of cerebral hemorrhage, and its related morbidity-mortality, brain arteriovenous malformations (bAVMs) are a rare and potentially life-threatening disease. Despite this, there is only one randomized controlled trial on bAVM management, A Randomized trial of Unruptured Brain Arteriovenous malformations (ARUBA). The results of the ARUBA trial favor a noninterventional approach in the case of an unruptured bAVM; however, implementation of these findings is challenging in daily practice. Instead, management of bAVM relies on multidisciplinary discussions that lead to patient-specific strategies based on patient preferences, local expertise, and experience in referral centers. Considering the diverse patterns of presentation and numerous treatment modalities, implementing standardized guidelines in this context proves challenging, notwithstanding the recommendations or expert opinions offered. Endovascular treatment (EVT) of bAVM can be curative, or can serve as an adjunct treatment prior to surgery or radiosurgery ("pre-EVT"). EVT practice is in constant evolution (i.e., venous approach, combination with surgery during the same anesthesia, etc.). Liquid embolic agents such as ethylene vinyl alcohol (EVOH) copolymer and cyanoacrylates (CYA), and their method of injection to increase bAVM occlusion have also benefited from technical evolutions such as the use of adjunctive flow arrest techniques (mini balloons, pressure cooker technique, and multiple catheters). Further research is necessary to evaluate the advantages and disadvantages of EVT for bAVM.

Transvenous retrograde pressure cooker technique for embolization of an ethmoidal dural arteriovenous fistula.

SummaryEthmoidal dural arteriovenous fistulas (DAVFs) are rare lesions, accounting for approximately 10% of intracranial DAVFs.1 2 As ethmoidal DAVFs commonly demonstrate cortical venous drainage, treatment is always warranted.2-6 Endovascular transvenous embolization has been increasingly reported as an effective and safe treatment for ethmoidal DAVFs, and since occlusion of the central retinal artery and resulting blindness are not a concern, it has an advantage over transarterial embolization.3-6 To ensure curative embolization, we adopted the transvenous retrograde pressure cooker technique (RPCT), creating a plug with n-butyl cyanoacrylate (NBCA) in the draining vein to allow a more comprehensive and efficient injection of Onyx (Medtronic, MN) while avoiding excessive reflux.7 8 In this technical video (video 1), we report the first case using the transvenous RPCT for successful Onyx embolization of an ethmoidal DAVF, with emphasis on the technical nuances of the RPCT and important tips to avoid periprocedural complications.neurintsurg;jnis-2023-020393v1/V1F1V1Video 1 Video demonstrating Onyx embolization of an ethmoidal dural arteriovenous fistula using the transvenous retrograde pressure cooker technique.

Diagnosis and endovascular management of vasospasm after aneurysmal subarachnoid hemorrhage - survey of real-life practices.

BACKGROUND: Vasospasm and delayed cerebral ischemia (DCI) are the leading causes of morbidity and mortality after intracranial aneurysmal subarachnoid hemorrhage (aSAH). Vasospasm detection, prevention and management, especially endovascular management varies from center to center and lacks standardization. We aimed to evaluate this variability via an international survey of how neurointerventionalists approach vasospasm diagnosis and endovascular management. METHODS: We designed an anonymous online survey with 100 questions to evaluate practice patterns between December 2021 and September 2022. We contacted endovascular neurosurgeons, neuroradiologists and neurologists via email and via two professional societies - the Society of NeuroInterventional Surgery (SNIS) and the European Society of Minimally Invasive Neurological Therapy (ESMINT). We recorded the physicians' responses to the survey questions. RESULTS: A total of 201 physicians (25% [50/201] USA and 75% non-USA) completed the survey over 10 months, 42% had >7 years of experience, 92% were male, median age was 40 (IQR 35-46). Both high-volume and low-volume centers were represented. Daily transcranial Doppler was the most common screening method (75%) for vasospasm. In cases of symptomatic vasospasm despite optimal medical management, endovascular treatment was directly considered by 58% of physicians. The most common reason to initiate endovascular treatment was clinical deficits associated with proven vasospasm/DCI in 89%. The choice of endovascular treatment and its efficacy was highly variable. Nimodipine was the most common first-line intra-arterial therapy (40%). Mechanical angioplasty was considered the most effective endovascular treatment by 65% of neurointerventionalists. CONCLUSION: Our study highlights the considerable heterogeneity among the neurointerventional community regarding vasospasm diagnosis and endovascular management. Randomized trials and guidelines are needed to improve standard of care, determine optimal management approaches and track outcomes.

Pulsatile tinnitus caused by an aneurysm of the transverse-sigmoid sinus: a new case report and review of literature.

A 28-year-old woman consulted for disabling pulsatile tinnitus. Clinical examination suggested a venous etiology. An aneurysm of the transverse-sigmoid sinus was identified on computed tomography angiography (CTA) and confirmed by digital subtraction angiography. Endovascular occlusion of the aneurysm with detachable coils permanently eliminated the bruit. Thus, this report is of a new case of pulsatile tinnitus caused by an aneurysm of the transverse-sigmoid sinus, with a focus on a literature review and etiopathophysiology. Embryological studies suggest that these aneurysms represent a partial remnant of the petrosquamous sinus.

Bailout stentectomy of 47 self-expandable intracranial stents.

BACKGROUND: Self-expanding stents are increasingly being deployed for stent-assisted coiling or flow diversion of intracranial aneurysms. Complications related to stent misbehavior may arise, however, including lack of expansion, device displacement, or parent vessel thrombosis. We present our experience of various stent removal techniques (stentectomy) with a focus on technical and clinical outcomes. METHODS: Stentectomy was attempted either with a single device, including the Alligator, Microsnare, or Solitaire, or by combining a Microsnare with a second device. Dual techniques included in this report are the Snare-over-Stentretriever technique we developed using a Microsnare and a Solitaire, and the previously described Loop-and-Snare technique using a Microsnare and a microwire. The technical success and complication rate, as well as the clinical outcome using the mRS were analyzed. RESULTS: Forty-seven stentectomies were attempted in 36 patients treated for 37 aneurysms. Forty-two devices (89.3%) were successfully retrieved. Single-device stentectomy was successful in 34% of cases, compared with 74% with dual-device techniques. Of the 20 patients with a thrombosed parent or efferent vessel, 17 were successfully recanalized using stentectomy. All successful stentectomy patients made a clinically uneventful recovery, except one with a minor postoperative stroke (mRS 1 at discharge). Failed stentectomy was associated with major ischemic stroke in two patients and death in one patient. There were no stentectomy-related vessel perforations or dissections. CONCLUSION: While various single devices can be used to safely retrieve dysfunctional intracranial self-expandable stents, dual-device techniques are more than twice as effective, according to our experience.

Effectiveness of very low profile thrombectomy device in primary distal medium vessel occlusion, as rescue therapy after incomplete proximal recanalization or following iatrogenic thromboembolic events.

BACKGROUND: Recent progress with smaller retrievers has expanded the ability to reach distal brain arteries. We herein report recanalization, bleeding complications and short-term clinical outcomes with the smallest currently known low profile thrombectomy device in patients with primary or secondary distal medium vessel occlusion (DMVO). METHODS: We performed a retrospective analysis of 115 patients receiving mechanical thrombectomy (MT) in DMVO using the extended Thrombolysis in Cerebral Infarction (eTICI), European Cooperative Acute Stroke Study (ECASS) II classification, The National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) scores at admission and discharge to evaluate outcomes. Patients were stratified into three groups: (1) primary isolated distal occlusion (n=34), (2) secondary distal occlusion after MT of a proximal vessel occlusion (n=71), or (3) during endovascular treatment of aneurysms or arteriovenous malformations (AVMs) (n=10). RESULTS: Successful distal recanalization, defined as an eTICI score of 2b67, 2c and 3, was achieved in 74.7% (86/115) of patients. More specifically, it was 70.5% (24/34), 73.2% (52/71), and 100% (10/10) of primary DMVO, secondary DMVO after proximal MT, and rescue MT during aneurysm or AVM embolization, respectively. Symptomatic intraparenchymal bleeding occurred in 6.9% (eight patients). In-hospital mortality occurred in 18.1% (19/105) of patients with stroke. The most common cause of death was large infarct, old age, and therapy limitation. CONCLUSION: Direct or rescue MT of DMVO using a very low profile thrombectomy device is associated with a high rate of successful recanalization and a reasonable rate of symptomatic hemorrhagic complication, despite a risk of 18.1% hospital mortality in elderly patients. Further trials are needed to confirm our results and assess long-term clinical outcomes.

The transvenous retrograde pressure cooker technique for the curative embolization of high-grade brain arteriovenous malformations.

BACKGROUND: Transvenous embolization of brain arteriovenous malformations (AVMs) can be curative. We aimed to evaluate the cure rate and safety of the transvenous retrograde pressure cooker technique (RPCT) using coils and n-butyl-2-cyanoacrylate as a venous plug. METHODS: All AVM patients treated via transvenous embolization between December 2004 and February 2017 in a single center were extracted from our database. Inclusion criteria were: inability to achieve transarterial cure alone; AVM < 3 cm; and single main draining vein. Outcome measures were immediate and 90 days' angiographic AVM occlusion rate, and morbidity and mortality at 30 days and 12 months, according to the modified Rankin Scale (mRS) score. RESULTS: Fifty-one patients (20 women; median age 47 years) were included. A majority (71%) were high grade (3 to 5 in the Spetzler-Martin classification). AVMs were deeply seated in 30 (59%) and cortical in 21 patients (41%). Thirty-three patients were previously embolized transarterially (65%). All patients but one were cured within a single session with the RPCT (96%). Cure was confirmed on follow-up digital subtraction angiography at 3 months in 82% of patients. Three patients experienced intracranial hemorrhage (6%), one requiring surgical evacuation. There were no deaths. One treatment-related major permanent deficit was observed (2.0%). Mean mRS before treatment, at 30 days, and 12 months after RPCT was 1.5, 1.5, and 1.3, respectively. CONCLUSIONS: The retrograde pressure cooker technique can be curative in carefully selected high-grade AVMs. Long-term follow-up and prospective studies are needed to confirm our results.

Flow driven robotic navigation of microengineered endovascular probes.

Minimally invasive medical procedures, such as endovascular catheterization, have considerably reduced procedure time and associated complications. However, many regions inside the body, such as in the brain vasculature, still remain inaccessible due to the lack of appropriate guidance technologies. Here, experimentally and through numerical simulations, we show that tethered ultra-flexible endovascular microscopic probes can be transported through tortuous vascular networks with minimal external intervention by harnessing hydrokinetic energy. Dynamic steering at bifurcations is performed by deformation of the probe head using magnetic actuation. We developed an endovascular microrobotic toolkit with a cross-sectional area that is orders of magnitude smaller than the smallest catheter currently available. Our technology has the potential to improve state-of-the-art practices as it enhances the reachability, reduces the risk of iatrogenic damage, significantly increases the speed of robot-assisted interventions, and enables the deployment of multiple leads simultaneously through a standard needle injection and saline perfusion.

Association of initial imaging modality and futile recanalization after thrombectomy.

OBJECTIVE: To test the hypothesis that selection by initial imaging modality (MRI vs CT) is associated with rate of futile recanalizations (FRs) after mechanical thrombectomy (MT), we assessed this association in a multicenter, retrospective observational registry (BEYOND-SWIFT [Registry for Evaluating Outcome of Acute Ischemic Stroke Patients Treated With Mechanical Thrombectomy], NCT03496064). METHODS: In 2,011 patients (49.7% female, median age 73 years [61-81]) included between 2009 and 2017, we performed univariate and multivariate analyses regarding the occurrence of FR. FRs were defined as 90-day modified Rankin Scale (mRS) score 4-6 despite successful recanalization in patients selected by MRI (n = 690) and CT (n = 1,321) with a sensitivity analysis considering only patients with mRS 5-6 as futile. RESULTS: MRI as compared to CT resulted in similar rates of subsequent MT (adjusted odds ratio [aOR] 1.048, 95% confidence interval [CI] 0.677-1.624). Rates of FR were as follows: 571/1,489 (38%) FR mRS 4-6 including 393/1,489 (26%) FR mRS 5-6. CT-based selection was associated with increased rates of FRs compared to MRI (44% [41%-47%] vs 29% [25%-32%], p < 0.001; aOR 1.77 [95% CI 1.25-2.51]). These findings were robust in sensitivity analysis. MRI-selected patients had a delay of approximately 30 minutes in workflow metrics in real-world university comprehensive stroke centers. However, functional outcome and mortality were more favorable in patients selected by MRI compared to patients selected with CT. CONCLUSIONS: CT selection for MT was associated with an increased risk of FRs as compared to MRI selection. Efforts are needed to shorten workflow delays in MRI patients. Further research is needed to clarify the role of the initial imaging modality on FR occurrence and to develop a reliable FR prediction algorithm.

Percutaneous CT-guided treatment of osteochondritis dissecans of the sacroiliac joint.

Osteochondritis dissecans (OCD) is a joint disorder that affects the articular cartilage and subchondral bone, most commonly at the knee. OCD of the sacroiliac joint is extremely rare. Management of OCD remains controversial, and surgery is often needed, especially when conservative treatment fails. We present a rare case of OCD involving the left sacroiliac joint successfully treated by percutaneous computed tomography-guided retrograde drilling and debridement.