Immune Thrombocytopenic Purpura and Intracranial Stenting.

Patients with immune thrombocytopenic purpura (ITP) presenting with indications for dual antiplatelet therapy (DAPT) can be difficult to manage due to the precarious balance of managing the need for increased platelet counts as well as inhibition of platelet activity. This case represents a 65 year old woman with ITP who presented with a bilateral subarachnoid hemorrhage secondary to a left ophthalmic aneurysm that required placement of a pipeline embolization device (PED) necessitating DAPT. After treatment of her ITP with pulse dexamethasone for four days, she was safely discharged on one month of DAPT with aspirin and ticagrelor then switched to aspirin monotherapy without any immediate complications. During her period of DAPT, she did not receive additional medical treatment for her ITP. This case successfully presents a high-risk ITP patient requiring DAPT for a neurosurgical procedure and illustrates that these patients can be safely and successfully treated with DAPT once their ITP is stabilized.

Comparison of Gelatin/Polylysine- and Silk Fibroin/SDF-1α-Coated Mesenchymal Stem Cell-Seeded Intracranial Stents.

Endothelialization of the aneurysmal neck is essential for aneurysm healing after endovascular treatment. Mesenchymal stem cell (MSC)-seeded stents can promote aneurysm repair. The biological effects of coated and uncoated nitinol intracranial stents seeded with MSCs on vascular cells and macrophage proliferation and inflammation are investigated. Two stent coatings that exert pro-aggregation effects on MSCs via different mechanisms are examined: gelatin/polylysine (G/PLL), which enhances cell adhesion, and silk fibroin/SDF-1α (SF/SDF-1α), which enhances chemotaxis. The aim is to explore the feasibility of MSC-seeded coated stents in the treatment of intracranial aneurysms. The G/PLL coating provides the highest cytocompatibility and blood compatibility substrate for MSCs and vascular cells and promotes cell adhesion and proliferation. Moreover, it enhances MSC secretion and regulation of vascular cell and macrophage proliferation and chemotaxis. Although the SF/SDF-1α coating promotes MSC secretion and vascular cell chemotaxis, it induces a greater degree of macrophage proliferation, chemotaxis, and secretion of pro-inflammatory factors. MSC-seeded stents coated with G/PLL may benefit stent surface endothelialization and reduce the inflammatory response after endovascular treatment of intracranial aneurysm. These effects may improve aneurysm healing and increase the cure rate.

Comparative Outcome Analysis of Enterprise and Neuroform Stent-Assisted Coiling of Cerebral Aneurysms: A Review of the Literature.

INTRODUCTION: One of the popular treatment strategies for complex cerebral aneurysms with wide necks or low dome-to-neck ratios is stent-assisted coiling. The most widely used intracranial stents for stent-assisted coiling are Neuroform (NF) and Enterprise (EP) stents. The purposes of this study are to review the recent literature of the past 5 years to compare outcomes between the EP and NF stent-assist coiling systems so as to comment on the safety, efficacy, complications, and recurrence rate of stent-assisted coiling in general. METHODS: PubMed was used to search for all published literature of NF or EP stent-assisted coiling of unruptured cerebral aneurysms from January 2014 to August 2019 with the search terms of "Enterprise stent-assisted coiling," "Neuroform stent," and "Neuroform vs. Enterprise stent." RESULTS: Twenty two publications met the inclusion criteria which encompass 1764 patients and 1873 aneurysms. Out of these 1873 aneurysms, 1007 aneurysms were treated with EP stent and 866 aneurysms were treated with NF stent. The overall outcome was low rates of thromboembolic complications (4.37%) and intracranial hemorrhage (1.13%), low permanent morbidity (1.70%) and mortality (0.40%), and lower rate of recanalization (11%). Data analysis shows an overall higher rate of complication and recurrence of aneurysm and lower overall rate of aneurysmal occlusion in the patients where EP stent was used in comparison to NF stent. However, this difference was not statistically significant. CONCLUSIONS: The review of two stent-assisted coiling devices using EP and NF stents including 1873 aneurysms in 1764 patients revealed that overall, it is safe and effective with comparable outcomes.

Neurovascular devices for the treatment of intracranial aneurysms: emerging and future technologies.

Introduction: Despite numerous advances in the endovascular treatment of intracranial aneurysms (IAs), treatment in cases of wide-neck, complex configurations or branching locations remains challenging. Apart from the paradigm shift introduced by flow diverters, several other devices have seen the light or are under development in order to address these challenges.Areas covered: We performed a review of the novel implantable endovascular devices which have been introduced for the treatment of IAs, from 1 January 2014 to 1 September 2019, excluding classic flow diverter and intracranial stent designs.Expert opinion: Alternative designs have been proposed for the treatment of IAs at branching positions, which do not jail the side branches, with or without flow diversion effect, most of which with good initial outcomes. Endosaccular devices have also been proposed, some of which with lower initial total occlusion rates. Alternative materials such as biopolymers have also been proposed and are under bench research. Despite the challenges in the exploitation of some of the new devices, most of them seem to provide solutions to some current technical shortcomings. The exploitation of the biological phenomena and the physical properties of the devices will allow us to expand the therapeutic armamentarium for more complex IA cases.

Small Tenuous Intracranial Arteries Can Well Tolerate the Deployment of 2 Stents in Y Configuration or an Overlapping Manner in Treating Intracranial Aneurysms.

OBJECTIVE: To investigate parent vessel response to deployment of 2 stents for treatment of cerebral aneurysms. METHODS: Fifteen patients (11 women and 4 men; age range, 25-83 years) with 18 wide-necked intracranial aneurysms were treated with 2 stents with or without subsequent coiling. The vascular diameter was measured and compared within the native parent artery, and the single stent and double stent were measured and compared before and immediately after stenting and at angiographic follow-up. RESULTS: Thirty stents were deployed. Before stenting, the mean vessel diameter was 3.4 ± 0.21 mm at point A, 3.06 ± 0.18 mm at point B, 3.16 ± 0.21 mm at point C, 2.67 ± 0.27 mm at point D, and 2.56 ± 0.23 mm at point E. The deployment of 2 stents resulted in statistically significant increases in both the average vascular diameter and cross-sectional area at points C (3.51 ± 0.22 mm, P = 0.0006; and 9.76 ± 1.17 mm2, P = 0.001, respectively) and E (2.88 ± 0.32 mm, P = 0.01; and 7.28 ± 1.46 mm2, P = 0.02, respectively) compared with prestenting. At angiographic follow-ups, compared with before stenting, significant increases were documented at point C (3.42 ± 0.22 mm and 9.42 ± 1.37 mm2, respectively) at first angiographic follow-up but at points A (3.62 ± 0.45 mm and 10.51 ± 2.37 mm2, respectively) and B (3.26 ± 0.24 mm and 8.47±1.26 mm2, respectively) at second angiographic follow-up. No significant vascular stenosis was demonstrated at the double-stent segment compared with the single-stent or native artery segments. CONCLUSIONS: The small tenuous cerebral arteries can well tolerate the deployment of 2 stents for the treatment of intracranial aneurysms.

A Comparison of Magnetic Resonance Angiography Techniques for the Evaluation of Intracranial Aneurysms Treated With Stent-assisted Coil Embolization.

AIM: To identify the effective magnetic resonance angiography (MRA) technique to monitor intracranial aneurysms treated with stent-assisted coiling. MATERIALS AND METHODS: Retrospective analysis of various MRA techniques was performed in 42 patients. Three neuroradiologists independently compared non-contrast time of flight (ncTOF) MRA of the head, contrast-enhanced time of flight (cTOF) MRA of the head and dynamic contrast-enhanced MRA (CEMRA) of the head and neck or of the head. Digital subtraction angiography (DSA) was available for comparison in 32 cases. Inter-rater agreement (kappa statistic) was assessed. RESULTS: Artifactual in-stent severe stenosis or flow gap was identified by ncTOF MRA in 23 of 42 cases (55%) and by cTOF MRA in 23 of 38 cases (60%). DSA excluded in-stent stenosis or occlusion in all 32 cases. No difference was noted between ncTOF and cTOF in the demonstration of neck remnants or residual aneurysms in three cases each. CEMRA of the head and neck or of the head was rated superior to ncTOF and cTOF MRA by all three investigators in seven out of eight cases. In one case, all three techniques demonstrated signifcant artifacts due to double stent placement during coiling. The kappa statistic revealed 0.8 agreement between investigators. CONCLUSIONS: In the assessment of stent-assisted coiling of intracranial aneurysm, both ncTOF and cTOF MRA show similar results. CEMRA tends to show better flow signals in stent and residual aneurysm.