Tonetti, Daniel A.

Background Larger “macrowires” may facilitate microcatheter-free delivery of large-bore aspiration catheters (ACs) for intracranial endovascular mechanical thrombectomy. We examined the safety and efficacy of the Aristotle Colossus Guidewire for this use. Methods In this retrospective analysis of prospective data from 12 institutions, we identified anterior circulation endovascular mechanical thrombectomy cases involving the Aristotle Colossus guidewire over a 12-month period. The primary efficacy endpoint was successful delivery of the AC to the site without the use of adjunct devices. Multivariable logistic regression was performed with clinically relevant covariables. Results In 122 patients (median age 74 years (interquartile range (IQR) 63–82)), most intracranial occlusions were in the M1 segment of the middle cerebral artery (95/122, 78.0%). The primary endpoint of microcatheter-free AC delivery was met in 87.7% (107/122) of patients; 93/122 (76.2%) patients underwent microcatheter-free delivery with successful reperfusion via contact aspiration (modified thrombolysis in cerebral infarction grade ≥ 2B). The median number of passes was 1 (IQR 1–2). Multivariable regression demonstrated that severe internal carotid artery tortuosity or cervical loop presence (odds ratio (OR): 0.09, 95% confidence interval (CI): 0.01–0.54, p = 0.01) and presence of intracranial atherosclerotic disease (OR: 0.15, 95% CI: 0.03–0.83, p = 0.03) were significantly associated with lower odds of successful AC delivery over the guidewire. Intraprocedural vasospasm occurred in 4.9% (6/122) of cases; there were no reports of vessel dissection or perforation. Conclusions We demonstrate the favorable performance of the Aristotle Colossus guidewire for anterior circulation ischemic stroke intervention. The macrowire appears to safely facilitate navigation of the neurovasculature by large-bore ACs without the need for microcatheter and/or stentriever.

BACKGROUND AND OBJECTIVES: First-line therapy for most intracranial dural arteriovenous fistulas (dAVFs) is endovascular embolization, but some require microsurgical ligation due to limited endovascular accessibility, anticipated lower cure rates, or unacceptable risk profiles. We investigated the most common surgically treated dAVF locations and the approaches and outcomes of each. METHODS: The Consortium for Dural Arteriovenous Fistula Outcomes Research database was retrospectively reviewed. Patients who underwent dAVF microsurgical ligation were included. Patient demographics, angiographic information, surgical details, and postoperative outcomes were collected. The 5 most common surgically treated dAVF locations were analyzed about used surgical approaches and postoperative outcomes. Univariate analyses were performed with statistical significance set at a threshold of P < .05. RESULTS: In total, 248 patients in the Consortium for Dural Arteriovenous Fistula Outcomes Research database met inclusion criteria. The 5 most common surgically treated dAVF locations were tentorial, anterior cranial fossa (ACF), transverse-sigmoid sinus (TSS), convexity/superior sagittal sinus (SSS), and torcular. Most tentorial dAVFs were approached using a suboccipital, lateral supracerebellar infratentorial approach (39.3%); extended retrosigmoid approach (ERS) (25%); or posterior subtemporal approach (19.6%). All ACF dAVFs used a subfrontal approach; 5.3% also included an anterior interhemispheric approach. Most TSS dAVFs were ligated via ERS (31.3%) or subtemporal (31.3%) approaches. All convexity/SSS dAVFs used an interhemispheric approach. All torcular dAVFs used the suboccipital, lateral supracerebellar infratentorial approach, with 10.5% undergoing simultaneous ERS craniotomy. Angiographic occlusion rates after microsurgery were 85.5%, 100%, 75.8%, 79.2%, and 73.7% for tentorial, ACF, TSS, convexity/SSS, and torcular dAVFs, respectively ( P = .02); the permanent neurological complication rates were 1.8%, 2.6%, 9.1%, 0%, and 0% ( P = .31). There were no statistically significant differences in development of complications ( P = .08) or Modified Rankin Scale at the last follow-up ( P = .11) by fistula location. CONCLUSION: Although endovascular embolization is the first-line treatment for most intracranial dAVFs, surgical ligation is an important alternative. ACF and tentorial fistulas particularly demonstrate high rates of postoperative obliteration.

OBJECTIVE The placement of flow-diverting devices has become a common method of treating unruptured intracranial aneurysms of the internal carotid artery. The progressive improvement of aneurysm occlusion after treatment—with low complication and rupture rates—has led to a dilemma regarding the management of aneurysms in which occlusion has not occurred within 6–24 months. The authors aimed to identify clinical consensus regarding management of intracranial aneurysms displaying persistent filling 6–24 months after flow diversion and to ascertain questions that may drive future investigation. METHODS An international panel of 67 experts was invited to participate in a multistep Delphi consensus process on the treatment of intracranial aneurysms after failed flow diversion. RESULTS Of the 67 experts invited, 23 (34%) participated. Qualitative analysis of an initial survey with open-ended questions resulted in 51 statements regarding management of aneurysms showing persistent filling after flow diversion. The statements were grouped into 8 categories, and in the second round, respondents rated the degree of their agreement with each statement on a 5-point Likert scale. Flow diverters with surface modifiers did not influence administration of dual-antiplatelet therapy according to 83%. Consensus was also reached regarding the definition of treatment failure at specific time points, including at 6 months if there is aneurysm growth or persistent rapid flow through the entirety of the aneurysm (96%), at 12 months if there is aneurysm growth or symptom onset (78%), and at 24 months if there is persistent filling regardless of size and filling characteristics (74%). Although experts agreed that the degree of intimal hyperplasia or in-device stenosis could not be ascertained by noninvasive imaging alone (83%), only 65% chose digital subtraction angiography as the preferred modality. At 6 and 12 months, retreatment is preferred if there is persistent filling with aneurysm growth (96%, 96%), device malposition (48%, 87%), or a history of subarachnoid hemorrhage (65%, 70%), respectively, and at 24 months if there is persistent filling without reduction in aneurysm size (74%). Experts favored treatment with an additional flow diverter (87%) over aneurysm clipping, applying the same principles for follow-up (83%) and treatment failure (91%) as for the first flow diverter. CONCLUSIONS The authors present the consensus practices of experts in the management of intracranial aneurysms without occlusion 6–24 months after treatment with a flow-diverting device.

OBJECTIVE Treatment of intracranial aneurysms by flow diversion is safe and effective and is increasingly popular. However, the correct treatment paradigm for aneurysms incompletely treated by initial placement of a flow diverter has not been established, nor have the subsequent natural history and occlusion rates of such aneurysms. The authors sought to outline the natural history of such aneurysms, which to date have been considered partially treated. METHODS The authors retrospectively reviewed consecutive cases from 6 high-volume neurointerventional services, including all cases in which the first follow-up imaging after placement of a flow diverter showed incomplete occlusion of the aneurysm, and for which subsequent clinical and/or radiological follow-up was available. All included patients were treated with the Pipeline Flex embolization device or the Pipeline Flex embolization device with Shield Technology. Subsequent radiographic and clinical outcome data were collected and analyzed using the Kaplan-Meier survival function. RESULTS A total of 263 patients with persistently patent aneurysms on first follow-up imaging after flow diversion were identified. Of these, 204 had clinical follow-up and 152 had additional imaging follow-up. Of this final cohort, 148 aneurysms were unruptured, and 4 were ruptured. The average aneurysm size by maximum dimension was 10.8 mm. The average recorded follow-up was 27.8 months in the cohort, with some patients followed for as long as 9 years from treatment. Over the course of 403 person-years of follow-up, no delayed aneurysm ruptures were recorded. Both with and without retreatment, aneurysms showed a trend toward progressive occlusion over time. Complications related to device placement were low. CONCLUSIONS Aneurysms that have been incompletely treated by flow diversion have a benign natural history with progression toward occlusion over time, with or without retreatment.

Abstract Background Stereotactic radiosurgical rhizolysis of the trigeminal nerve is an established modality increasingly employed to alleviate the symptoms of refractory trigeminal neuralgia. This study analyzes the academic impact of the top 100 cited articles on the radiosurgical management of trigeminal neuralgia. Methods The Scopus database was searched for articles containing “radiosurgery” and one or more of “trigeminal neuralgia,” “trigeminus neuralgia,” and “tic douloureux.” The top 100 articles written in English were arranged in descending order by citation count. Documents were evaluated for authors, publication year, journal and impact factor, total citations, nationality, study type, radiosurgical modality, and the affiliated institution. Quantitative and qualitative analyses were performed on the data. Results The most cited articles were published between 1971 and 2019. The average citation per year was 4.3. The most targeted anatomic area was the “root entry zone” or proximal portion of the cisternal segment of the trigeminal nerve. The most utilized modality was Gamma Knife radiosurgery. The country with the highest number of publications was the United States. Thirty-six percent of the articles were published in the Journal of Neurosurgery. Lunsford, Kondziolka, Flickinger, and Régis, respectively, were the most frequently listed co-authors. The most prolific institute was the University of Pittsburgh Medical Center. Conclusion Stereotactic radiosurgery is an important modality in the management of medically or surgically refractory trigeminal neuralgia. This analysis assesses its contributions over the past five decades to identify trends in treatment practices for neurosurgeons and to highlight areas where further study is needed.

BACKGROUND: Dural arteriovenous fistulas (dAVFs) located at craniocervical junction are extremely rare (1%-2% of intracranial/spinal dAVFs). Their angio-architectural complexity renders endovascular embolization to be challenging given multiple small feeders with risk of embolysate reflux into vertebral artery and limited transvenous access. The available literature discussing microsurgery for these lesions is limited to few case reports. OBJECTIVE: To report a multicenter experience assessing microsurgery safety/efficacy. METHODS: Prospectively maintained registries at 13 North American centers were queried to identify craniocervical junction dAVFs treated with microsurgery (2006-2021). RESULTS: Thirty-eight patients (median age 59.5 years, 44.7% female patients) were included. The most common presentation was subarachnoid/intracranial hemorrhage (47.4%) and myelopathy (36.8%) (92.1% of lesions Cognard type III-V). Direct meningeal branches from V3/4 vertebral artery segments supplied 84.2% of lesions. All lesions failed (n = 5, 13.2%) or were deemed inaccessible/unsafe to endovascular treatment. Far lateral craniotomy was the most used approach (94.7%). Intraoperative angiogram was performed in 39.5% of the cases, with angiographic cure in 94.7% of cases (median imaging follow-up of 9.2 months) and retreatment rate of 5.3%. Favorable last follow-up modified Rankin Scale of 0 to 2 was recorded in 81.6% of the patients with procedural complications of 2.6%. CONCLUSION: Craniocervical dAVFs represent rare entity of lesions presenting most commonly with hemorrhage or myelopathy because of venous congestion. Microsurgery using a far lateral approach provides robust exposure and visualization for these lesions and allows obliteration of the arterialized draining vein intradurally as close as possible to the fistula point. This approach was associated with a high rate of angiographic cure and favorable clinical outcomes.