Search

In this review article, we aim to provide a summary of the discoveries and developments that were instrumental in the evolution of the Neurointerventional field. We begin with developments in the advent of Diagnostic Cerebral Angiography and progress to cerebral aneurysm treatment, embolization in AVMs and ischemic stroke treatment. In the process we discuss many persons who were key in the development and maturation of the field. A pivotal aspect to rapid growth in the field has been the multidisciplinary involvement of the different neuroscience specialties and therefore we close out our discussion with excitement about ongoing and future developments in the field with a focus on treatments in the non-cerebrovascular disease realm., Competing Interests: None declared., (Thieme. All rights reserved.)

Dural arteriovenous fistulas (DAVFs) are abnormal communications between meningeal arteries and dural venous sinuses and/or cortical veins. Although many fistulas are benign and do not require treatment, some may carry a significant risk of bleeding or cause symptoms and warrant treatment. This review provides a review of various aspects of intracranial DAVFs including epidemiology, pathophysiology, clinical presentation, imaging characteristics, classification, natural history, and management options. By exploring these topics, we aim to enhance understanding of this condition and facilitate patient care., Competing Interests: None declared., (Thieme. All rights reserved.)

Background: The Treatment of Brain Arteriovenous Malformations Study (TOBAS) is an all-inclusive pragmatic study comprising 2 randomized clinical trials (RCTs). Patients excluded from the RCTs are followed in parallel treatment and observation registries, allowing a comparison between RCT and registry patients., Methods: The first randomized clinical trial (RCT-1) offers 1:1 randomized allocation of intervention versus conservative management for patients with arteriovenous malformation (AVM). The second randomized clinical trial (RCT-2) allocates 1:1 pre-embolization or no pre-embolization to surgery or radiosurgery patients judged treatable with or without embolization. Characteristics of RCT patients are reported and compared to registry patients., Results: From June 2014 to May 2021, 1010 patients with AVM were recruited; 498 patients were observed and 373 were included in the treatment registries. Randomized allocation in RCT-1 was applied to 139 (26%) of the 512 patients (including 127 of 222 [57%] with unruptured AVMs) considered for curative treatment. RCT-1 AVM patients differed (in rupture status, Spetzler-Martin grade and baseline modified Rankin Score) from those in the observation or treatment registries (P < 0.001). Most patients had small (<3 cm; 71%) low-grade (Spetzler-Martin I-II; 64%) unruptured (91%) AVMs. The allocated management was conservative (n = 71) or curative (n = 68), using surgery (n = 39), embolization (n = 16), or stereotactic radiosurgery (n = 13). Pre-embolization was considered for 179/309 (58%) patients allocated/assigned to surgery or stereotactic radiosurgery; 87/179 (49%) were included in RCT-2. RCT-2 patient AVMs differed in size, eloquence and grade from patients of the pre-embolization registry (P < 0.01). Most had small (<3 cm in 82%) low-grade (83%) AVMs in non-eloquent brain (64%)., Conclusions: Patients included in the RCTs differ significantly from registry patients. Meaningful results can be obtained if multiple centers actively participate in the TOBAS RCTs., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Objective: The Treatment of Brain Arteriovenous Malformations Study (TOBAS) is a pragmatic study that includes 2 randomized trials and registries of treated or conservatively managed patients. The authors report the results of the surgical registry., Methods: TOBAS patients are managed according to an algorithm that combines clinical judgment and randomized allocation. For patients considered for curative treatment, clinicians selected from surgery, endovascular therapy, or radiation therapy as the primary curative method, and whether observation was a reasonable alternative. When surgery was selected and observation was deemed unreasonable, the patient was not included in the randomized controlled trial but placed in the surgical registry. The primary outcome of the trial was mRS score > 2 at 10 years (at last follow-up for the current report). Secondary outcomes include angiographic results, perioperative serious adverse events, and permanent treatment-related complications leading to mRS score > 2., Results: From June 2014 to May 2021, 1010 patients were recruited at 30 TOBAS centers. Surgery was selected for 229/512 patients (44%) considered for curative treatment; 77 (34%) were included in the surgery versus observation randomized trial and 152 (66%) were placed in the surgical registry. Surgical registry patients had 124/152 (82%) ruptured and 28/152 (18%) unruptured arteriovenous malformations (AVMs), with the majority categorized as low-grade Spetzler-Martin grade I-II AVM (118/152 [78%]). Thirteen patients were excluded, leaving 139 patients for analysis. Embolization was performed prior to surgery in 78/139 (56%) patients. Surgical angiographic cure was obtained in 123/139 all-grade (89%, 95% CI 82%-93%) and 105/110 low-grade (95%, 95% CI 90%-98%) AVM patients. At the mean follow-up of 18.1 months, 16 patients (12%, 95% CI 7%-18%) had reached the primary safety outcome of mRS score > 2, including 11/16 who had a baseline mRS score ≥ 3 due to previous AVM rupture. Serious adverse events occurred in 29 patients (21%, 95% CI 15%-28%). Permanent treatment-related complications leading to mRS score > 2 occurred in 6/139 patients (4%, 95% CI 2%-9%), 5 (83%) of whom had complications due to preoperative embolization., Conclusions: The surgical treatment of brain AVMs in the TOBAS registry was curative in 88% of patients. The participation of more patients, surgeons, and centers in randomized trials is needed to definitively establish the role of surgery in the treatment of unruptured brain AVMs. Clinical trial registration no.: NCT02098252 (ClinicalTrials.gov).

Foreign body embolization is a rare and potentially under-recognized complication of neuroendovascular procedures. This complication should be considered in the differential diagnosis for clinical or radiological deterioration following neurovascular interventions. We report a case of foreign body hydrophilic coating embolization that occurred following an attempted flow diversion of an intracranial aneurysm with dramatic flare-up after repeat exposure. We also provide a literature review of all reported cases of hydrophilic polymer embolization following flow diversion procedures.

Background and Purpose: Early major recurrence (EMR) of cerebral aneurysms treated by coiling has not been investigated. The purpose of this study is to characterize the frequency and risk factors of this phenomenon., Materials and Methods: A retrospective review was performed of consecutive patients who presented with ruptured and unruptured cerebral aneurysms and underwent coiling from July 2009 to June 2019 at a university hospital. We defined EMR as recurrence of the aneurysm greater than its initial size within the first 6 months of an initial satisfactory coil embolization. Patient demographics, clinical information, aneurysm characteristics, angiographic and technical details were reviewed., Results: From July 2009 to June 2019, 338 aneurysms (190 unruptured aneurysms and 148 ruptured cerebral aneurysms) underwent coiling and satisfied our study criteria. Among these patients, 23 patients (19 ruptured and 4 unruptured aneurysms) were found to have recurrent aneurysm. Of those, 4 were found to have early major aneurysm regrowth occurring within 6 months after coiling (1.2%). The detection of the EMR was as early as 4 weeks and as late as 20 weeks after the initial coil embolization. The average detection time was 10 ± 7.2 weeks (mean ± SD, range:4-20 weeks). In each case, the recurrent aneurysm cavity was more than twice the initial size of presentation. All aneurysms with major recurrence were ruptured with low aspect ratios (dome height to neck ratio) and involved a communicating segment. All patients underwent successful retreatment of the recurrent aneurysm with good outcome., Conclusions: Early major recurrence of treated aneurysms is a rare but important complication that harbors an impending risk of re-rupture. Early control angiography after endovascular coiling may be warranted for small ruptured aneurysms, even in cases in which the initial result seems technically satisfactory.