Influence of preoperative embolisation on resection of brain arteriovenous malformations: cohort study.

PURPOSE: Preoperative endovascular embolisation is a widely used adjunct for the surgical treatment of brain arteriovenous malformations (AVMs). However, whether this improves completeness of AVM resection is unknown, as previous analyses have not adjusted for potential confounding factors. We aimed to determine if preoperative endovascular embolisation was associated with increased rate of complete AVM resection at first surgery, following adjustment for Spetzler-Martin grade items. METHODS: We identified a cohort of all patients undergoing first ever AVM resection in a specialist neurosciences unit in the NHS Lothian Health Board region of Scotland between June 2004 and June 2022. Data was prospectively extracted from medical records. Our primary outcome was completeness of AVM resection. We determined the odds of complete AVM resection using binomial logistic regression with adjustment for Spetzler-Martin grading system items: maximum nidus diameter, eloquence of adjacent brain and the presence of deep venous drainage. RESULTS: 88 patients (median age 40y [IQR 19-53], 55% male) underwent AVM resection. 34/88 (39%) patients underwent preoperative embolisation and complete resection was achieved at first surgery in 74/88 (84%). Preoperative embolisation was associated with increased adjusted odds of complete AVM resection (adjusted odds ratio [aOR] 8.6 [95% confidence interval (95% CI) 1.7-67.7]; p = 0.017). The presence of deep venous drainage was associated with reduced chance of complete AVM resection (aOR 0.18 [95% CI 0.04-0.63]; p = 0.009). CONCLUSIONS: Preoperative embolisation is associated with improved chances of complete AVM resection following adjustment for Spetzler-Martin grade, and should therefore be considered when planning surgical resection of AVMs.

The pEGASUS-HPC stent system for stent-assisted coiling of cerebral aneurysms: a multicenter case series.

BACKGROUND: Stent-assisted coiling (SAC) is a well-established method for treatment of wide-necked intracranial aneurysms. In this multicenter, retrospective case series we evaluated SAC with a new low-profile, laser-cut stent with an antithrombogenic hydrophilic polymer coating (pEGASUS-HPC) for the treatment of intracranial aneurysms. METHODS: Patients treated with pEGASUS-HPC SAC for one or more intracranial aneurysms were retrospectively included. Clinical, imaging, and procedural parameters as well as clinical and imaging follow-up data were recorded. RESULTS: We treated 53 aneurysms in 52 patients in six neurovascular centers between August 2021 and November 2022. Thirty-seven patients (69.8%) were female. Mean age was 57 (±11.7) years. Twenty-nine patients were treated electively, 23 in the acute phase (22 with aneurysmal subarachnoid hemorrhage (SAH), and 1 with a partially thrombosed aneurysm causing ischemic events). One intraprocedural thromboembolic event and three postprocedural ischemic complications occurred in two (8.7 %) of the SAH patients and in one of the elective patients (3.45%). Overall aneurysm occlusion was Raymond Roy (RR) I in 36 (69.2%), RR II in 9, and RR III in 9 cases. Follow-up imaging was available for 23 patients after an average of 147.7 (±59.6) days demonstrating RR I occlusion in 22 (95.5%) and RR II in 1 patient. CONCLUSION: SAC with the pEGASUS-HPC stent system demonstrates rates of periprocedural safety and effectiveness that are comparable with previously reported series for stent-assisted coil embolization.

Coating (Coating to Optimize Aneurysm Treatment in the New Flow Diverter Generation) study. The first randomized controlled trial evaluating a coated flow diverter (p64 MW HPC): study design.

BACKGROUND: Due to its high efficacy, flow diversion is increasingly used in the management of unruptured and recanalized aneurysms. Because of the need for perioperative dual antiplatelet treatment (DAPT), flow diversion is not indicated for the treatment of ruptured aneurysms. To overcome this major limitation, surface modification-'coating'-of flow diverters has been developed to reduce platelet aggregation on the implanted device, reduce thromboembolic complications, and facilitate the use of coated flow diverter treatment in patients with single antiplatelet treatment (SAPT). COATING (Coating to Optimize Aneurysm Treatment in the New Flow Diverter Generation) is a prospective, randomized, multicenter trial that aims to determine whether the use of the coated flow diverter p64 MW HPC under SAPT is non-inferior (or even superior) to the use of the bare flow diverter p64 MW under DAPT in relation to thromboembolic and hemorrhagic complications. METHODS: Patients with unruptured or recanalized aneurysms for which endovascular treatment with a flow diverter is indicated will be enrolled and randomly assigned on a 1:1 ratio to one of two treatment groups: p64 MW HPC with SAPT or p64 MW with DAPT. RESULTS: The primary endpoint is the number of diffusion-weighted imaging lesions visualized via MRI assessed within 48 hours (±24 hours) of the index procedure. Secondary primary endpoints are comparing safety and efficacy in both arms. CONCLUSIONS: This randomized controlled trial is the first to directly compare safety and efficacy of coated flow diverters under SAPT with bare flow diverters under DAPT. TRIAL REGISTRATION NUMBER: http://clinicaltrials.gov/ - NCT04870047.

Diversion-p64: results from an international, prospective, multicenter, single-arm post-market study to assess the safety and effectiveness of the p64 flow modulation device.

BACKGROUND: The use of flow diversion to treat intracranial aneurysms has increased in recent years. OBJECTIVE: To assess the safety and angiographic efficacy of the p64 flow modulation device. METHODS: Diversion-p64 is an international, prospective, multicenter, single-arm, study conducted at 26 centers. The p64 flow modulation device was used to treat anterior circulation aneurysms between December 2015 and January 2019. The primary safety endpoint was the incidence of major stroke or neurologic death at 3-6 months, with the primary efficacy endpoint being complete aneurysm occlusion (Raymond-Roy Occlusion Classification 1) on follow-up angiography. RESULTS: A total of 420 patients met the eligibility criteria and underwent treatment with the p64 flow modulation device (mean age 55±12.0 years, 86.2% female). Mean aneurysm dome width was 6.99±5.28 mm and neck width 4.47±2.28 mm. Mean number of devices implanted per patient was 1.06±0.47, with adjunctive coiling performed in 14.0% of the cases. At the second angiographic follow-up (mean 375±73 days), available for 343 patients (81.7%), complete aneurysm occlusion was seen in 287 (83.7%) patients. Safety data were available for 413 patients (98.3%) at the first follow-up (mean 145±43 days) with a composite morbidity/mortality rate of 2.42% (n=10). CONCLUSIONS: Diversion-p64 is the largest prospective study using the p64 flow modulation device. The results of this study demonstrate that the device has a high efficacy and carries a low rate of mortality and permanent morbidity.

Early experience treating intracranial aneurysms using Accero: a novel, fully visible, low profile braided stent with platinum-nitinol composite wire technology.

BACKGROUND: Accero is an innovative, fully visible, self-expanding braided stent with platinum-nitinol composite wire technology, produced by Acandis. OBJECTIVE: To assess the technical success and safety of this new stent by evaluating the intraprocedural behavior and complication rate, and the short-term follow-up results. METHODS: Forty-one consecutive patients suitable for stent-assisted coiling were selected for the use of Accero in an 11-month period. Clinical, procedural, and angiographic data, as well as 30-day morbidity, were recorded. The angiographic results, clinical follow-up at 30 days, and early imaging follow-up at 3 or 6 months were analyzed, when available. RESULTS: Forty-one aneurysms were treated with stent-assisted coiling. All cases were elective, of which 19 were previously untreated aneurysms and 22 were recurrent aneurysms. Aneurysm location was anterior communicating artery complex (16), basilar (12 cases), middle cerebral artery bifurcation (9 cases), and internal cerebral artery (4 cases). The stent was successfully deployed and aneurysm occlusion with coils achieved in 100% of our patients. One case of on table in-stent thrombosis occurred, which resolved after administration of glycoprotein IIB/IIIA inhibitor, with no clinical consequence, and one case of postoperative hematoma at the arteriotomy site, which was managed conservatively. On early follow-up, available for 37 patients, the complete occlusion rate was 76%, with only two recurrences needing further treatment. Satisfactory aneurysm occlusion was therefore achieved in 95% of cases. CONCLUSION: Stent-assisted coiling with the Accero braided stent proved safe and effective.

De novo distal middle cerebral artery aneurysm post-excision of intracerebral arteriovenous malformation in an 8-year old.

Cerebral arteriovenous malformations (AVMs) are frequently associated with concurrent aneurysms. These aneurysms are commonly haemodynamically related to the AVM and can be classified into extranidal or intranidal in reference to the AVM nidus. An aneurysm arising from an artery that does not angiographically contribute to the blood flow to the AVM is uncommon. A distal middle cerebral artery (dMCA) aneurysm itself is also a rare presentation, especially in paediatric population. We present a rare case of dMCA aneurysm that was noted after successful surgical management of a ruptured AVM in an 8-year-old child and its management. BACKGROUND: About 10-30% of patients with cerebral arteriovenous malformation (AVM) have an associated artery aneurysm. The majority of these aneurysms are flow-related to the malformation. These aneurysms can be classified into extranidal or intranidal in reference to the AVM nidus Rammos et al Am J Neuroradiol 37:1966-1971, [1]. An aneurysm arising from a different artery that does not angiographically contribute to the blood flow associated with the AVM is less common and would generally be regarded as unrelated to the AVM. Distal cerebral artery aneurysm itself is also a rare presentation, comprising of 1-7% of all middle cerebral artery aneurysm. In children, mycotic infection and dissection are the two most common causes for aneurysm in this location. Unlike in adults, berry aneurysms are uncommon in children. We describe a young patient who was found to have distal middle cerebral artery (dMCA) aneurysm in follow-up DSA (Digital Subtraction Angiogram) after the initial successful surgical treatment for a cerebral frontal AVM. In this particular case, endovascular repair is thought to be the best strategy to treat the aneurysm. However, there still remains a lack of consensus of the best management strategy (surgery or endovascular) in treating flow-related aneurysms in general. This is usually based on an individual case scenario and the treatment is tailored depending on various factors including the expertise of the treating team.