Clinical outcomes of delayed mechanical thrombectomy: Descriptive analysis and development of a screening tool.

BACKGROUND AND PURPOSE: Limited data guide the selection of patients with large vessel occlusion ischaemic stroke who may benefit from referral to a distant tertiary centre for mechanical thrombectomy (MT). We aimed to characterize this population, describe clinical outcomes and develop a screening system to identify patients most likely to benfit from delayed mechanical thrombectomy (MT). METHODS: We undertook a retrospective cohort analysis enrolling patients transferred from regional sites to one of two MT comprehensive stroke units with a time from non-contrast computed tomography (NCCT) of the brain to reperfusion of 4 h or more. We describe Alberta Stroke Programme Early Computed Tomography Score (ASPECTS), National Institute of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) in our patients and compare these patients to those in extended-time-window trials. Lastly, we developed and validated a scoring model to help clinicians identify appropriate patients based on variables associated with poor outcomes. RESULTS: We included 563 patients, 46% of whom received thrombolysis; the median (interquartile range [IQR]) ASPECTS was 8 (7-10) and the median (IQR) NIHSS score was 16 (11-20). The median (IQR) symptom to mechanical reperfusion time was 390 (300-580) min. Eight patients (1%) had a symptomatic haemorrhage. We achieved good clinical outcome (defined as mRS score ≤2) in 299 patients (54%). Age, diabetes, NIHSS score and ASPECTS were used to create a weighted scoring system with a validated area under the curve of 0.83 (95% confidence interval 0.74-0.92). CONCLUSION: Our study shows, in highly selected patients, that delayed MT many hours after baseline NCCT is associated with good clinical outcomes. However, older patients with diabetes, high NIHSS score and low ASPECTS may not benefit from transfer to a hub centre many hours away for MT in this model of care.

Fast-tracking acute hospital care--from bed crisis to bed crisis.

We describe here the results of a continuous quality improvement (CQI) project, the Delayed Discharge Project, in a general medicine service in a New Zealand teaching hospital. Average length of stay (ALOS) dropped by 2.6 days (6.5 to 3.9), readmission rates did not rise, costs of service delivery dropped by US dollars 2.4 million, patient numbers increased by 145 (2445 to 2590), while bed numbers reduced from 56 to 32 and ward outliers all but disappeared, suggesting success. However, 2 years after the successful cost-saving measures were introduced the new system crashed as a result of additional bed closures and organisational restructures.

Stroke thrombolysis in New Zealand: data from the first 6 months of the New Zealand Thrombolysis Register.

The New Zealand National Stroke Network introduced a National Stroke Thrombolysis Register on the first of January 2015 to assist with quality assurance and continuous service improvement. In the first 6 months, there were 179 [75 women, mean (SD) age 69.9 (14) years] treated with stroke thrombolysis out of a total of 2,796 ischaemic stroke patients, giving a national thrombolysis rate of 6.4%. The median [Inter-quartile range (IQR)] onset-to-treatment time was 154 (125-190) minutes, and the median (IQR) door-to-needle time was 74.5 (55.7-105.0) minutes. The rate of symptomatic intracranial haemorrhage following thrombolysis was 4.4%. These results are similar to other international centres, and indicate an approximate doubling of the proportion of stroke patients treated with stroke thrombolysis since a 2009 national audit. However, there is need for on-going efforts to improve treatment rates and process efficiency, particularly door-toneedle times.

Comparative in vitro evaluation of microspherical embolisation agents.

This study describes the comparative performance of four commercially available microspherical embolisation products: Embosphere, Embogold, Contour SE and Bead Block. A series of in vitro evaluations were designed to assess the mechanical and biological characteristics of these biomaterials. Size distribution analysis revealed sieving techniques used to fractionate the embolics produced similar size distributions. The forces required to compress Embosphere, Embogold and Bead Block were in the range 21-27.5 kPa. Contour SE was significantly more compressible at approximately 5 kPa. However, recoverability of Contour SE required several minutes in contrast to the other products, a phenomenon attributed to its macroporous structure. When time taken to reach and remain in suspension was studied, results showed that the products quickly reached equilibrium with contrast agent. Bead Block was maintained in suspension for twice as long as the other products. Catheter deliverability was assessed and found to be dependent upon both microsphere and catheter, the best combination being Bead Block delivered via the Progreat catheter. Both the blood contacting SEM and plasma coagulation time showed none of the products were pro-thrombic or pro-coagulatory, each producing comparable results. Small differences in physical properties such as compressibility, could play an important role in delivery and effectiveness of vessel blockage. Currently all products are used routinely in clinical practice.