ORCID Profile
0000-0002-2353-9901
Current Organisation
The University of Auckland
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Publisher: Wiley
Date: 12-12-2019
DOI: 10.1111/ANAE.14940
Abstract: It is unknown whether systolic blood pressure augmentation during endovascular thrombectomy improves clinical outcomes. This pilot randomised controlled trial aimed to assess the feasibility of differential systolic blood pressure targeting during endovascular thrombectomy procedures for anterior circulation ischaemic stroke. Fifty-one eligible patients fulfilling the national criteria for endovascular thrombectomy were randomly assigned to receive either standard or augmented systolic blood pressure management from the start of anaesthesia to recanalisation of the target vessel. Systolic blood pressure targets for the standard and augmented groups were 130-150 mmHg and 160-180 mmHg, respectively. The study achieved all feasibility targets, including a recruitment rate of 3.5 participants per week and median (IQR [range]) of mean systolic blood pressure separation between groups of 139 (135-143 [115-154]) vs. 167 (150-175 [113-188]) mmHg, p < 0.001. Data completeness was 99%. Independent functional recovery at 90 days (modified Rankin Scale 0, 1 or 2) was achieved in 30 (59%) patients, which is consistent with previously published data. There were no safety concerns with trial procedures. In conclusion, a large randomised controlled efficacy trial of standard vs. augmented systolic blood pressure management during endovascular thrombectomy is feasible.
Publisher: BMJ
Date: 25-07-2017
DOI: 10.1136/PRACTNEUROL-2016-001569
Abstract: Prompt and accurate diagnosis is the foundation of acute ischaemic stroke care. Multiple positive endovascular thrombectomy trials in ischaemic stroke patients with large vessel occlusions have further emphasised this but also added complexity to treatment decisions. CT angiography is now routine for patients who present with an acute stroke syndrome around the world. Members of the neurology and stroke teams (rather than radiologists) are often the first doctors to lay eyes on the CT images and are best equipped to integrate the clinical picture with the imaging findings. A sound understanding of acute stroke imaging is therefore essential for clinicians who work with acute stroke patients. This review describes some pearls we have gleaned from our own experience in acute stroke imaging as well as some potential follies to be avoided.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2021
DOI: 10.1161/STR.52.SUPPL_1.P486
Abstract: Background: The treatment approach of aspiration rather than use of a stent retriever as first-line therapy is increasingly regarded as standard of care for acute ischemic stroke. Continued technological advances include the ongoing development of aspiration embolectomy catheters that are larger in bore, guided by delivery catheters that are more maneuverable through the tortuous neurovasculature. Methods: SUMMIT NZ (ACTRN12619000890134p) was designed as a prospective, single-arm, open label clinical trial at two sites in New Zealand. Eligible participants were patients presenting with acute ischemic stroke from either anterior or posterior circulation large-vessel occlusion within 24 hours of onset, a National Institutes of Health Stroke Scale Score ≥ 6 and a pre-stroke modified Rankin Score of ≤ 2. A novel tapered tip delivery catheter was specifically designed to deliver 0.070” and 0.088” aspiration catheters telescoped through a specialized 8F 90 cm introducer sheath (Route 92 Medical, Inc. San Mateo, CA). The primary effectiveness endpoint was arterial revascularization as measured by a modified Thrombosis in Cerebrovascular Infarction (mTICI) score of 2b or greater at the end of angiography after all endovascular treatments as adjudicated by an independent core laboratory. The primary safety endpoints were device-related peri-procedural complications such as dissection or perforation, symptomatic Intracranial Cerebral Hemorrhage (SICH) at 24 hours and embolization to a previously uninvolved territory. Results: From September 27, 2019 to June 23, 2020, 18 subjects (mean age 69.5, NIHSSS 15.2, time last known well 6.2 hours) were enrolled with a diagnosis of acute ischemic stroke. Acute occlusion was located in the middle cerebral artery (78%, 14/18) and internal carotid artery (22%, 4/18). Successful revascularization was achieved in 94% (17/18) of subjects. No serious adverse device effects have been reported. Conclusions: Preliminary findings suggest that aspiration first mechanical embolectomy using a novel telescoping system including an 0.088” inner diameter aspiration catheter achieves a high rate of arterial revascularization with an acceptable safety profile. A full report on enrollment and results are to be presented.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2023
Abstract: In patients with stroke with large‐vessel occlusion and extensive ischemic change denoted by low Alberta Stroke Programme Early Computed Tomography Score (ASPECTS), the role of bridging thrombolysis before endovascular thrombectomy (EVT) is still to be determined. We aimed to examine the impact of ischemic change on clinical outcomes and how this is modified by bridging thrombolysis in patients treated with EVT. Consecutive patients undergoing anterior circulation EVT from a prospectively collected registry were included in this retrospective analysis. ASPECTS was evaluated from baseline noncontrast computed tomography scans with lower scores indicating larger areas of ischemic change. Outcome measures included symptomatic intracranial hemorrhage and functional independence (modified Rankin Scale score, 0–2) at day 90. Multivariable logistic regression models with interaction terms between ASPECTS and bridging thrombolysis were created. ASPECTS was treated as numeric variable in the primary analysis and trichotomized (ASPECTS ≤5, 6–8, 9–10) in a sensitivity analysis. A total of 872 patients undergoing EVT (384 women, mean±SD age of 67±15, baseline National Institute of Health Stroke Scale 16 [interquartile range, 11–20]) were included. A total of 549 (63%) patients were transferred from primary stroke centers for EVT and 436 (50%) received bridging intravenous thrombolysis with alteplase. On baseline computed tomography scan, median [interquartile range] ASPECTS was 8 [7–9], with 408 (47%) having minimal (ASPECTS 9–10), 376 (43%) moderate (ASPECTS 6–8), and 88 (10%) extensive (ASPECTS ≤5) ischemic change. With decreasing numeric ASPECTS, the probability of functional independence reduced (ASPECTS main effect adjusted odds ratio, 1.36 [95% CI, 1.23–1.52] P .001), but this was attenuated in those with bridging thrombolysis (interaction P =0.046). This interaction was significant for patients transferred to the EVT center after thrombolysis (interaction P =0.03) but not for patients presenting directly to the EVT center (interaction P =0.46). The interaction between ASPECTS and bridging thrombolysis was not significant when ASPECTS was split into the 3 categories ( P =0.35). In a cohort of patients undergoing EVT where most were transferred from a primary stroke center, ischemic change was associated with decreased probability functional independence, but this effect was attenuated with bridging thrombolysis. These results suggest that patients with large areas of ischemic change may still benefit from the earliest possible reperfusion afforded by bridging thrombolysis.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2020
DOI: 10.1161/STROKEAHA.119.028160
Abstract: In ischemic stroke, body temperature is associated with functional outcome. However, the relationship between temperature and outcome may differ in the intraischemic and postischemic phases of stroke. We aimed to determine whether body temperature before or after endovascular thrombectomy (EVT) for large vessel occlusion stroke is associated with clinical outcomes. Consecutive EVT patients were identified from a prospective registry. Temperature measurements within 24 hours of admission were stratified into pre-EVT (preprocedural and intraprocedural) and post-EVT measurements, which served as surrogates for the intraischemic and postischemic phases of large vessel occlusion stroke, respectively. The primary outcome was functional independence, defined as a modified Rankin Scale score of 0, 1, or 2 at 3 months. Secondary outcomes included the ordinal shift of modified Rankin Scale scores at 3 months, symptomatic intracerebral hemorrhage, and mortality at 3 months. Four hundred thirty-two participants were included (59% men, mean±SD age 65.6±15.7 years). Multivariable logistic regression demonstrated that higher median pre-EVT temperature (per 1°C increase) was an independent predictor of reduced functional independence (odds ratio [OR], 0.66 [95% CI, 0.46–0.94] P =0.02), poorer modified Rankin Scale scores (common OR, 1.42 [95% CI, 1.08–1.85] P =0.01), and increased mortality (OR, 1.65 [95% CI, 1.02–2.69] P =0.04). Peak post-EVT temperature (per 1°C increase) was a significant predictor of elevated modified Rankin Scale scores (common OR, 1.39 [95% CI, 1.03–1.90] P =0.03) and higher mortality (OR, 1.66 [95% CI, 1.04–2.67] P =0.03). In patients with large vessel occlusion stroke treated with EVT, higher body temperatures during both the intraischemic and postischemic phases were associated with poorer clinical outcomes. Future research investigating the maintenance of normothermia or therapeutic hypothermia in patients needing to be transferred from primary to EVT-capable stroke centers could be considered.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 15-06-2021
DOI: 10.1212/WNL.0000000000012112
Abstract: To evaluate the safety and efficacy of intra-arterial thrombolysis (IAT) as an adjunct to endovascular thrombectomy (EVT) in ischemic stroke, we performed a systematic review and meta-analysis of the literature. Searches were performed using MEDLINE, Embase, and Cochrane databases for studies that compared EVT with EVT with adjunctive IAT (EVT + IAT). Safety outcomes included symptomatic intracerebral hemorrhage and mortality at 3 months. Efficacy outcomes included successful reperfusion (Thrombolysis in Cerebral Infarction score of 2b–3) and functional independence, defined as a modified Rankin Scale score of 0–2 at 3 months. Five studies were identified that compared combined EVT + IAT (IA alteplase or urokinase) with EVT only and were included in the random-effects meta-analysis. There were 1693 EVT patients, including 269 patients treated with combined EVT + IAT and 1,424 patients receiving EVT only. Pooled analysis did not demonstrate any differences between EVT + IAT and EVT only in rates of symptomatic intracerebral hemorrhage (odds ratio [OR]: 0.61, 95% confidence interval [CI]: 0.20–1.85 p = 0.78), mortality (OR: 0.77, 95% CI: 0.54–1.10 p = 0.15), or successful reperfusion (OR: 1.05, 95% CI: 0.52–2.15 p = 0.89). There was a higher rate of functional independence in patients treated with EVT + IAT, although this was not statistically significant (OR: 1.34, 95% CI: 1.00–1.80 p = 0.053). Adjunctive IAT appears to be safe. In specific situations, neurointerventionists may be justified in administering small doses of intra-arterial alteplase or urokinase as rescue therapy during EVT.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2020
DOI: 10.1161/STROKEAHA.119.027958
Abstract: Intracranial carotid artery calcification is associated with worse outcome in anterior circulation stroke patients who undergo endovascular thrombectomy. We investigated the association between vertebrobasilar artery calcification (VBAC) and outcome in patients undergoing endovascular thrombectomy for posterior circulation large vessel occlusion. Consecutive patients treated for posterior circulation large vessel occlusion from a prospective single-center registry were studied. VBAC was manually segmented on computed tomography brain scans. The associations between VBAC and VBAC volume, functional independence (90-day modified Rankin Scale score of 0–2), and 90-day mortality were assessed using propensity score–adjusted logistic regression. Sixty-four posterior circulation large vessel occlusion patients were included. Twenty-five (39.1%) patients had VBAC, and of these, the median (interquartile range) VBAC volume was 19.8 (6.65–23.4) mm 3 . VBAC was associated with reduced functional independence (OR, 0.19 [95% CI, 0.04–0.78] P =0.03) and increased mortality (OR, 9.44 [95% CI, 2.43–36.62] P =0.005). Larger VBAC volumes were a significant predictor of reduced functional independence and increased mortality. VBAC is an independent predictor of outcome in patients undergoing endovascular thrombectomy for posterior circulation large vessel occlusion. Considering the presence of VBAC might improve prognostication and shared treatment decision-making between patients, families, and physicians.
No related grants have been discovered for James Caldwell.