Citations

Background Bacteria and bacterial components have been associated with the activation of coagulation factors and initiating the blood clot formation. The aim of this study was to investigate whether bacterial populations are present in clots retrieved from patients that have suffered a large vessel occlusion acute ischemic stroke (AIS). Materials and methods Clot samples were collected from 20 AIS patients who underwent clot retrieval with mechanical thrombectomy. Patient clinical demographic details were noted. Expression of bacterial 16S rDNA was analyzed by standard and real-time polymerase chain reaction (PCR). Gram staining was performed to identify Gram-positive and Gram-negative bacteria. Results Both the real-time and standard PCR demonstrated no expression of 16S rDNA in any of the 20 clots samples from AIS patients. Gram staining results showed no expression of Gram-positive or Gram-negative bacteria present in the clot samples. Conclusion Our current study found no bacteria populations in the clots of AIS patients.

Abstract BACKGROUND Both stent-assisted coiling (SAC) and flow diversion with the Pipeline Embolization device (PED; Medtronic Inc) have been shown to be safe and clinically effective for treatment of small (<10 mm) unruptured aneurysms. However, the economic impact of these different techniques has not been established. OBJECTIVE To analyze the cost-effectiveness between stent-assisted coiling and flow diversion using PED, including procedural costs, long-term outcomes, and aneurysm recurrence. METHODS A decision-analytical study was performed with Markov modeling methods to simulate patients undergoing SAC or PED for treatment for unruptured aneurysms of sizes 5 and 7 mm. Input probabilities were derived from prior literature, and 1-way, 2-way, and probabilistic sensitivity analyses (PSA) were performed. RESULTS In base case calculation and PSA, PED was the dominant strategy for both the size groups, with and without consideration of indirect costs. One-way sensitivity analyses show that the conclusion remained robust when varying the retreatment rate of SAC from 0% to 50%, and only changes when the retreatment rate of PED > 49%. PED remained the more cost-effective strategy when the morbidity and mortality of PED increased by <55% and when those of SAC decreased by <37%. SAC only became cost-effective when the total cost of PED is >$73000 more expensive than the total cost of SAC. CONCLUSION With increasing use of PED for treatment of small unruptured anterior circulation aneurysms, our study indicates that PED is cost-effective relative to stent coiling irrespective of aneurysm size. This is due to lower aneurysm recurrence rate, as well as better health outcomes.

Abstract BACKGROUND Flow diversion (FD) is effective for treatment of intracranial internal carotid artery (ICA) aneurysms. OBJECTIVE To determine whether carotid siphon (CS) geometry influences the efficacy of FD when employed for ICA aneurysms. METHODS Outcomes of a consecutive series of patients with ICA aneurysms treated with FD were retrospectively reviewed. CS anatomy was quantified through measurement of the posterior, anterior, and anterosuperior bend angles in accordance with previously described methodology. The relationship of CS geometry to likelihood of incomplete aneurysm occlusion at 1 yr after treatment was assessed with multivariate logistic regression analysis. RESULTS There were 167 ICA aneurysms in 164 patients treated with FD during the study period. The mean age of our cohort was 55.7 yr (standard deviation [SD]: 12.3) and a majority of patients were female (145/164, 86.8%). Anterior (47.4 degrees vs 8.5, P < .001) and anterosuperior bend angles (100.9 vs 76.5, P = .002) were significantly greater in aneurysms that required repeat FD after initial treatment. On multivariate logistic regression analysis, increasing patient age (unit odds ratio [OR]: 1.05, 95% confidence interval [CI] 1.01-1.08; P = .003) and anterior bend angle ≥–3.5 (OR: 2.47, 95% CI 1.04-5.86; P = .046) were associated with increased odds of incomplete aneurysm occlusion at 1 yr after treatment. CONCLUSION These findings suggest that variations in CS anatomy may influence the efficacy of FD treatment and should be analyzed prior to offering FD for treatment of ICA aneurysms. Further investigation into the hemodynamic effects of CS geometry is warranted.

Summary Cardiac surgery has been shown to be associated with increased risk of acute ischemic stroke. This report presents a case of a successful mechanical embolectomy procedure to treat a patient for an acute ischemic stroke, which was caused by the cardiac embolization of a ‘foreign body’ containing debris following a redo sternotomy procedure for mitral valve replacement and tricuspid valve annuloplasty.

Introduction: The composition of acute ischemic stroke (AIS) blood clots can impact their successful removal via endovascular therapy. Identification of the clot composition prior to endovascular treatment may influence the optimal treatment strategy. In this study, we aimed to investigate the relationship between the Hounsfield Unit intensity on CT and machine-learned characterization of clot composition. Methods: Prior to endovascular treatment, each patient had a non-contrast CT performed. Histopathological analysis of the clots was performed and clot composition was quantified via standard thresholding techniques using Adobe Photoshop. In addition, following representative cell labeling by an expert pathologist, image segmentation algorithms (Orbital Image Analysis, Actelion Ltd.) were trained on each case to quantify composition by cell type. The clots were categorized into 3 groups: red blood cell (RBC) dominant (>50%), RBC proportion equal to fibrin and fibrin dominant (>50%). Correlations between clot composition and Hounsfield Units (HU) density on CT were assessed. A positive Hyperdense Artery Sign was defined as ≥50 HU. Results: Twenty patients were included in the study. There was a significant correlation between clots quantified using Adobe Photoshop Image-Pro and Orbit image analysis ( ρ = 0.837, p < 0.001). A significant relationship was found between clot composition and the presence of a HAS sign, ( X 2 (2) = 6.496, p = 0.039). There is a significant positive correlation between percentage of RBC in the clot and the presence of a HAS sign ( ρ = 0.632, p = 0.002**). There is also a significant positive correlation between the presence of fibrin-rich and the absence of a HAS sign ( ρ = 0.600, p = 0.004**). Conclusion: Machine learning software can accurately quantify AIS clot composition. The Hounsfield unit density of an AIS clot on a non-contrast CT correlates with the composition of the clot. Measuring the HU of the clot on CT prior to endovascular intervention may inform the clinician of the clot type and help to determine the most appropriate treatment strategy for that clot.

Endovascular therapy with mechanical thrombectomy is a formidable treatment for severe acute ischemic stroke caused by occlusion of a proximal intracranial artery. Its strong beneficial effect is explained by the high rates of very good and excellent reperfusion achieved with current endovascular techniques. However, there is a sizable proportion of patients who do not experience clinical improvement despite successful recanalization of the occluded artery and reperfusion of the ischemic territory. Factors such as baseline reserve, collateral flow, anesthesia and systemic factors have been identified as potential culprits for lack of improvement in the setting of timely and successful revascularization. Older age, baseline disability and perhaps radiological markers of chronic brain injury can affect the prognosis of patients treated with endovascular therapy. Collateral flow is a major determinant of outcome after endovascular therapy and it is manifested by the size of the core in relation to the volume of the salvageable tissue. Parenchymal and vascular imaging can help assess the quality of collateral flow, but the optimal radiological strategy for daily practice (i.e. the optimal combination of rapid availability and diagnostic precision) has not been established. A sizable body of observational evidence indicates that acute hypertension, hyperglycemia and fever are associated with worse outcomes after a stroke even after optimal reperfusion with endovascular therapy. Lastly, current randomized controlled trials in anesthesia for stroke demonstrate similar rates of good functional outcome between general anesthesia and conscious sedation suggesting equipoise exists.