Economic impact of the first pass effect in mechanical thrombectomy for acute ischaemic stroke treatment in Spain: a cost-effectiveness analysis from the national health system perspective.

OBJECTIVE: The mechanical thrombectomy (MT) benefit is related to the degree of reperfusion achieved. First pass effect (FPE) is defined as complete/near revascularisation of the large-vessel occlusion (modified Thrombolysis in Cerebral Infarction (mTICI) 2c-3) after a single device pass. This study assessed the health benefit and economic impact of achieving FPE for acute ischaemic stroke (AIS) patients from the Spanish National Health System (NHS) perspective. DESIGN: A lifetime Markov model was used to estimate incremental costs and health outcomes (measured in quality-adjusted life-years (QALYs)) of patients that achieve FPE. A subanalysis of the Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischaemic Stroke (STRATIS) registry was performed to obtain clinical outcomes. The base case included all patients that achieved at least a final mTICI ≥2 b, while the alternative scenario included all patients regardless of their final mTICI (0-3). Treatment costs were updated to reflect current practice based on expert panel consensus, while other acute and long-term costs were obtained from a previous cost-effectiveness analysis of MT performed in Spain. Sensitivity analyses were performed to assess the model's robustness. SETTING: Spanish healthcare perspective. PARTICIPANTS: AIS patients in Spain. INTERVENTIONS: FPE following MT. OUTCOME MEASURES: The model estimated QALYs, lifetime costs and net monetary benefit for the FPE and non-FPE group, depending on the inclusion of reperfusion groups and formal care costs. RESULTS: STRATIS subanalysis estimated significantly better clinical outcomes at 90 days for the FPE group in all scenarios. In the base case, the model estimated lifetime cost saving per patient of €16 583 and an incremental QALY gain of 1.2 years of perfect health for the FPE group. Cost savings and QALY gains were greater in the alternative scenario (-€44 289; 1.75). In all scenarios, cost savings were driven by the long-term cost reduction. CONCLUSION: Achieving FPE after MT can lead to better health outcomes per AIS patient and important cost savings for the Spanish NHS.

In vivo canine study of three different coatings applied to p64 flow-diverter stents: initial biocompatibility study.

BACKGROUND: Flow-diverter stents (FDSs) have revolutionised the treatment of intracranial aneurysms. However, associated dual antiplatelet treatment is mandatory. We investigated the biocompatibility of three proprietary antithrombogenic coatings applied to FDSs. METHODS: After Institutional Animal Care and Use Committee approval, four domestic juvenile female dogs (weight 19.9 ± 0.9 kg, mean ± standard deviation) were commenced on three different oral antiplatelet regimes: no medication (n = 1), acetylsalicylic acid (n = 2), and acetylsalicylic acid and clopidogrel (n = 1). Four p64 FDSs were randomly implanted into the subclavian, common carotid, and external carotid arteries of each dog, including both uncoated p64 stents and p64 stents coated with three different antithrombogenic hydrophilic coating (HPC). Angiography and histological examinations were performed. Wilcoxon/Kruskal-Wallis and ANOVA were used with p value < 0.05 considered as significant. RESULTS: Minimal inflammatory cell infiltration and no device-associated granulomatous cell inflammation were observed. No significant difference in adventitial inflammation (p = 0.522) or neointimal/medial inflammation (p = 0.384) between coated and uncoated stents as well as between the different stent groups regarding endothelial cell loss, surface fibrin/platelet deposition, medial smooth muscle cell loss, or adventitial fibrosis were found. Acute self-limiting thrombus formed on 6/16 implants (37.5%), and all of the thrombi were noted on devices implanted in the common or external carotid artery irrespective of the surface coating. Two of 12 p64 HPC-coated stents (16.7%) and 1/4 uncoated p64 stents (25%) showed severe or complete stenosis at delayed angiography. CONCLUSIONS: In these preliminary in vivo experiments, HPC-coated p64 FDSs appeared to be biocompatible, without acute inflammation.

Hydrophilic Stent Coating Inhibits Platelet Adhesion on Stent Surfaces: Initial Results In Vitro.

BACKGROUND: Endovascular stents and flow diverter stents (FDS) have revolutionized the treatment of intradural aneurysms; however, the need for dual anti-platelet treatment (DAPT) limits their use and can cause additional issues. Therefore, there is a need to develop stent coatings that negate the need for DAPT. METHODS: Two different hydrophilic polymer coatings (HPC-I and HPC-II) were used to coat small nickel titanium plates to initially test the hydrophilic properties of these coatings when applied to nickel titanium. The plates were subsequently incubated with non-medicated whole blood from healthy volunteers for 10 min and stained with a CD61 immunofluorescent antibody that allows detection of adherent platelets. The coatings were applied to FDS wires and were again incubated with non-medicated whole blood from the same volunteers. Scanning electron microscopy was used to detect adherent platelets on the wire surface. RESULTS: The HPC-II coating (1.12 ± 0.4%) showed a significantly lower CD61 +ve cell count (p ≤ 0.001) compared to both uncoated NiTi plates (48.61 ± 7.3%) and those with the HPC-I coating (mean 40.19 ± 8.9%). Minimal adherent platelets were seen on the FDS nickel titanium wires coated with the HPC-II compared to uncoated FDS under electron microscopy. CONCLUSION: There is a significant decrease in the number of adherent CD61 +ve platelets on nickel titanium surfaces coated with the HPC-II coating compared to uncoated surfaces. The coating can be successfully applied to the wires of flow diverters. The results of this study are promising with regard to the development of new anti-thrombogenic endovascular devices.

The Medina Embolic Device: early clinical experience from a single center.

OBJECTIVE: To report our initial experience with the Medina Embolic Device (MED) in unruptured intracranial aneurysms either as sole treatment or in conjunction with additional devices. METHODS: 15 consecutive patients (6 women, 9 men) with unruptured aneurysms were treated between September 2015 and April 2016. The aneurysm fundus measured at least 5 mm. We evaluated the angiographic appearances of treated aneurysms at the end of the procedure and at follow-up, the clinical status, complications, and requirement for adjunctive devices. RESULTS: The MED was successfully deployed in all but one case and adjunctive devices were required in 10 cases. Aneurysm locations were middle cerebral artery bifurcation (n=3), internal carotid artery (ICA) bifurcation (n=1), supraclinoid ICA (n=5), posterior communicating artery (n=1), anterior communicating artery (n=2), cavernous ICA (n=2), distal basilar sidewall (n=1), basilar tip (n=1). Three patients had complications although none could be attributed to the MED. Immediate angiographic results were modified Raymond-Roy classification (mRRC) I=1, mRRC II=5, mRRC IIIa=3, mRRC IIIb=5, and one patient showed contrast stasis within the fundus of the aneurysm. Follow-up angiography was available in 11 patients, with four showing complete aneurysm exclusion, six with stable remnants and one patient with an enlarging neck remnant. CONCLUSIONS: The MED represents a major step forward in the treatment of intracranial aneurysms. It can result in rapid exclusion of an aneurysm from the circulation and has a good safety profile. We believe that the true value of the MED will be in combining its use with adjunctive devices such as endoluminal flow diverters that will result in rapid aneurysmal exclusion.

Combined use of a pCONus and a Solitaire stent: Report of two cases.

Objective The aim of this study was to report our initial experience of the use of the pCONus neck protection device in conjunction with the Solitaire AB stent to assist in the endovascular management of complex intracranial aneurysms with arteries arising from both the neck and the dome of the aneurysm. Methods Two patients with unruptured aneurysms underwent elective endovascular management of their aneurysms, one arising from the middle cerebral artery bifurcation and one from the anterior communicating artery. Both aneurysms had vessels arising from the neck and dome of the aneurysm. We present the strategy involved to protect all the arterial branches and coil occlude the aneurysm, the angiographic appearances and clinical status of the patients. Results Both cases involved the combined use of a pCONus and Solitaire stent. The parent vessel and efferent branches were all preserved with exclusion of the aneurysm from the circulation. There were no intraoperative complications. One patient developed mild transient symptoms 24 hours post procedure, which had resolved completely on discharge. Conclusion The use of the pCONus in conjunction with the Solitaire stent is a useful combination when dealing with complex wide-necked aneurysms with arteries derived from the fundus of the aneurysm.

Endovascular treatment of acute internal carotid artery dissections: technical considerations, clinical and angiographic outcome.

INTRODUCTION: In acute internal carotid artery dissection (a-ICAD) with concomitant intracranial large vessel occlusion or haemodynamic impairment, the effectiveness of medical treatment is limited and endovascular therapy (EVT) can be considered. Feasibility, safety and outcome of EVT in a-ICAD are not well described yet. METHODS: From an institutional database, we retrospectively selected consecutive patients treated for a-ICAD between January 2007 and July 2015. We assessed recanalization results defining <50 % residual stenosis and mTICI ≥2b as successful. Procedural adverse events and symptomatic haemorrhages were reported as well as clinical outcome at 90 days defining a mRS ≤2 as favourable. Follow-up angiographies were reviewed and retreatments reported. RESULTS: In the defined period, 73 patients (mean age 48 years (31-73), mean NIHSS 11 (0-27)) received EVT for a-ICAD. The majority (60 %) had tandem occlusions. Cervical artery reconstruction was successful in 100 % and intracranial thrombectomy in 85 %. Thrombus formation (18 %) and thromboembolism (20 %) were the most frequent adverse events but clinically relevant only in 8 %. Symptomatic haemorrhage occurred in 5 %. Clinical outcome was favourable in 64 %, with a lower chance after tandem occlusion (55 vs. 79 %, p = 0.047). Death rate was 10 %. None of the patients developed recurrent ischaemic symptoms, but control angiography revealed abnormal findings of the reconstructed ICA in 38 % leading to retreatment in 17 %. CONCLUSION: EVT of a-ICAD is feasible with a predominantly favourable clinical outcome. Improvement of devices and techniques is warranted to reduce the risk of thrombus formation and thromboembolism during treatment and insufficient vessel wall healing thereafter.