Endovascular Treatment of Cerebrovascular Lesions Using Nickel- or Nitinol-Containing Devices in Patients with Nickel Allergies.

Nickel is used in many cerebral endovascular treatment devices. However, nickel hypersensitivity is the most common metal allergy, and the relative risk of treatment in these patients is unknown. This retrospective analysis identified patients with nickel or metal allergies who underwent cerebral endovascular treatment with nickel-containing devices. Seven patients with nickel and/or other metal allergies underwent treatment with 9 nickel-containing devices. None experienced periprocedural complications. No patient received treatment with corticosteroids or antihistamines. At a mean clinical follow-up for all patients of 22.8 months (range, 10.5-38.0 months), no patients had symptoms attributable to nickel allergic reactions. The mean radiographic follow-up for all patients at 18.4 months (range, 2.5-37.5 months) showed successful treatment of the targeted vascular pathologies, with no evidence of in-stent stenosis or other allergic or hypersensitivity sequelae. The treatment of cerebrovascular lesions with a nickel-containing device resulted in no adverse outcomes among these patients and was safe and effective.

Emergency Department Visits for Chronic Subdural Hematomas within 30 Days after Surgical Evacuation with and without Middle Meningeal Artery Embolization.

BACKGROUND AND PURPOSE: Middle meningeal artery embolization after surgical evacuation of a chronic subdural hematomas is associated with fewer treatment failures than surgical evacuation. We compared emergency department visits within 30 days for patients with chronic subdural hematomas with and without adjunctive middle meningeal artery embolization. MATERIALS AND METHODS: All cases of chronic subdural hematoma treated from January 1, 2018, through December 31, 2020, were retrospectively reviewed. Treatment was classified as surgery only or surgery combined with middle meningeal artery embolization. The primary outcome was 30-day emergency department presentation and readmission. RESULTS: Of 137 patients who met the study criteria, 28 (20%) underwent surgery combined with middle meningeal artery embolization. Of these 28 patients, 15 (54%) underwent planned middle meningeal artery embolization and 13 (46%) underwent embolization after surgical failure. The mean chronic subdural hematoma size at presentation in the group with surgery only (n = 109, 20.5 [SD, 6.9] mm) was comparable with that in the combined group (n = 28, 18.7 [SD, 4.5] mm; P = .16). A significantly higher percentage of the surgery-only group presented to the emergency department within 30 days compared with the combined group (32 of 109 [29%] versus 2 of 28 [7%] patients; P = .02). No significant difference was found with respect to readmission (16 [15%] versus 1 [4%] patient; P = .11). Nine patients (8%) in the surgery-only group were readmitted for significant reaccumulation or residual subdural hematoma compared with only 1 patient (4%) in the combined group (P = .40). CONCLUSIONS: Surgical evacuation combined with middle meningeal artery embolization in patients with chronic subdural hematoma is associated with fewer 30-day emergency department visits compared with surgery alone.

Multicenter Postmarket Analysis of the Neuroform Atlas Stent for Stent-Assisted Coil Embolization of Intracranial Aneurysms.

BACKGROUND AND PURPOSE: The Neuroform Atlas is a new microstent to assist coil embolization of intracranial aneurysms that recently gained FDA approval. We present a postmarket multicenter analysis of the Neuroform Atlas stent. MATERIALS AND METHODS: On the basis of retrospective chart review from 11 academic centers, we analyzed patients treated with the Neuroform Atlas after FDA exemption from January 2018 to June 2019. Clinical and radiologic parameters included patient demographics, aneurysm characteristics, stent parameters, complications, and outcomes at discharge and last follow-up. RESULTS: Overall, 128 aneurysms in 128 patients (median age, 62 years) were treated with 138 stents. Risk factors included smoking (59.4%), multiple aneurysms (27.3%), and family history of aneurysms (16.4%). Most patients were treated electively (93.7%), and 8 (6.3%) underwent treatment within 2 weeks of subarachnoid hemorrhage. Previous aneurysm treatment failure was present in 21% of cases. Wide-neck aneurysms (80.5%), small aneurysm size (<7 mm, 76.6%), and bifurcation aneurysm location (basilar apex, 28.9%; anterior communicating artery, 27.3%; and middle cerebral artery bifurcation, 12.5%) were common. A single stent was used in 92.2% of cases, and a single catheter for both stent placement and coiling was used in 59.4% of cases. Technical complications during stent deployment occurred in 4.7% of cases; symptomatic thromboembolic stroke, in 2.3%; and symptomatic hemorrhage, in 0.8%. Favorable Raymond grades (Raymond-Roy occlusion classification) I and II were achieved in 82.9% at discharge and 89.5% at last follow-up. mRS ≤2 was determined in 96.9% of patients at last follow-up. The immediate Raymond-Roy occlusion classification grade correlated with aneurysm location (P < .0001) and rupture status during treatment (P = .03). CONCLUSIONS: This multicenter analysis provides a real-world safety and efficacy profile for the treatment of intracranial aneurysms with the Neuroform Atlas stent.

Ortho-linked polyaryloxide ligands and their titanium complexes.

Ortho-linked polyphenols, quaterphenol L(OH)4, and moderately hindered terphenol PhL(OH)3 are developed as new multidentate polyaryloxide ligands for transition-metal chemistry. The polyphenols are synthesized using ortho-metalation and metal-catalyzed cross-coupling methodologies; the synthetic routes allow for facile electronic and steric modification of the basic ligand design. The Ti(IV) coordination chemistry of these ligands reveals a diverse collection of bridged structures: dimeric [Ti(mu-PhLO3)(OiPr)]2 (P2(1)/n, a = 12.2699(5) A, b = 11.7957(5) A, c = 21.238(1) A, beta = 94.551(1) degrees, Z = 2, T = 170(2) K), dimeric [Ti2(mu-PhLO3)2(mu-Cl)(Cl)(THF)] (P1, a = 11.212(1) A, b = 14.165(1) A, c = 22.447(2) A, alpha = 90.440(4) degrees, beta = 93.345(4) degrees, gamma = 111.164(4) degrees, Z = 2, T = 170(2) K), and trimeric [Ti3(mu,mu'-LO4)(mu-OiPr)2(OiPr)6] P2(1)/n, a = 11.1022(5) A, b = 18.7015(9) A, c = 24.409(1) A, beta = 95.369(2) degrees, Z = 4, T = 170(2) K). The reaction of TiCl3(THF)3 with [PhLO3]3- results in oxidation of Ti(III) to Ti(IV) and formation of the oxo dimer [Ti(PhLO3)(THF)]2(mu-O) (P1, a = 10.8649(6) A, b = 12.1882(7) A, c = 14.3349(9) A, alpha = 65.602(3) degrees, beta = 84.390(3) degrees, gamma = 86.582(3) degrees, Z = 1, T = 200(2) K); the oxo group presumably originates from the THF solvent. The titanium centers in these environments are either 5- or 6-coordinate, with distorted square pyramidal/trigonal bipyramidal and distorted octahedral geometries, respectively; the polyphenoxide chelate ligands are capable of bridging multiple oxophilic titanium sites.