Real-Time Visualization of a Transient Retinal Embolus.

This case report describes the real-time imaging of a transient retinal embolus in a patient experiencing episodes of monocular vision loss.

Development of a Short-Term Embolic Agent Based on Cilastatin for Articular Microvessels.

Background and Objectives: This study aimed to develop an embolic agent with short-term embolic effects using cilastatin as the basic material. Materials and Methods: The particle size distribution of 25 mg cilastatin-based short-term embolic agents was evaluated microscopically under three different mixing conditions. A total of thirty-six healthy male Sprague Dawley rats were divided into four groups. Each group of six rats was injected once into the tail artery with 0.4 mL each of (A) Cilastatin + D-Mannitol Mixture, (B) Iohexol, (C) Prepenem, and (D) embolization promoter (EGgel). Results: A visual inspection of the tail appearance of rats in each group was performed at 0, 3, 7, 15, and 21 days. At weeks 1 and 3, three rats per group were euthanized, and histopathological analyses were performed on the specimens obtained from each group. No significant differences were observed on day 7, but mild inflammation was observed in Group (D) on day 15. Histopathological inflammation scoring of tail central artery embolization was performed using a six-point scale (from 0 = absent to 5 = marked inflammation). Three groups were formed consisting of six male New Zealand white rabbits each: control, positive control, and test groups. The control group received an Iohexol injection (rabbits: 0.8 mL). The positive control and experimental groups were injected with prepenem and cilastatin/D-mannitol compound, respectively (0.8 mL), and vascular angiography was performed. The order of occlusion progression after embolization was as follows: test group, positive control group, and control group. Conclusions: We developed a cilastatin/D-mannitol compound that exhibits characteristics of short-term embolization by utilizing the pharmacokinetic properties of cilastatin and the crystalline material D-mannitol. We evaluated its particle size distribution microscopically, conducted histopathological evaluation including inflammation via animal experiments, and assessed the embolization effect.

Anticoagulation in embolic acute limb ischaemia-an observational study.

The management of embolic acute limb ischaemia commonly involves determining aetiology and performing emergency invasive procedures. This detailed study aimed to determine the impact of manipulation of anticoagulation in the aetiology of emboli in acute limb ischaemia and determine the efficacy of primary anticoagulation therapy vs. invasive interventions. Material and methods: Data collection was conducted at a single institution on a cohort of patients presenting consecutively with embolic acute limb ischaemia over one year. Two groups were compared, one receiving anticoagulation as primary therapy with those undergoing invasive treatment as the internal comparison group. Results: A likely haematological causation was identified in 22 of 38 presentations, related to interruption of anticoagulation in cardiac conditions, the majority atrial fibrillation (n=12), or hypercoagulable states (n=10). Limb salvage was pursued in 36 patients employing anticoagulation (n=19) or surgical embolectomy (n=17) as the primary therapy in upper and lower limbs (n=17 vs n=19 respectively). Despite delays often well beyond six hours and a range of ischaemic severity in both groups, 35 of 36 patients achieved full or substantive restoration of function with improved perfusion. Regarding anatomical distribution of arterial disease and therapy, three patients with multi-level disease proceeded to embolectomy following anticoagulation. Embolectomy was undertaken most often for proximal emboli and more profound paralysis. Conclusions: Anticoagulation and coagulopathy are commonly implicated in the aetiology of arterial emboli, with omission of effective anticoagulation in atrial fibrillation being associated in almost 1/3 of presentations. Whilst more profound limb paralysis and proximal or multi-level disease tended to be managed surgically, primary anticoagulation therapy alone or with a secondary embolectomy was effective across the spectrum of ischaemia severity and despite significant delays beyond guideline recommendations.

Association Between Oral Anticoagulant Adherence and Serious Clinical Outcomes in Patients With Atrial Fibrillation: A Long-Term Retrospective Cohort Study.

BACKGROUND: Patients with atrial fibrillation are frequently nonadherent to oral anticoagulants (OACs) prescribed for stroke and systemic embolism (SSE) prevention. We quantified the relationship between OAC adherence and atrial fibrillation clinical outcomes using methods not previously applied to this problem. METHODS AND RESULTS: Retrospective observational cohort study of incident cases of atrial fibrillation from population-based administrative data over 23 years. The exposure of interest was proportion of days covered during 90 days before an event or end of follow-up. Cox proportional hazard models were used to evaluate time to first SSE and the composite of SSE, transient ischemic attack, or death and several secondary outcomes. A total of 44 172 patients were included with median follow-up of 6.7 years. For direct OACs (DOACs), each 10% decrease in adherence was associated with a 14% increased hazard of SSE and 5% increased hazard of SSE, transient ischemic attack, or death. For vitamin K antagonist (VKA) the corresponding increase in SSE hazard was 3%. Receiving DOAC or VKA was associated with primary outcome hazard reduction across most the proportion of days covered spectrum. Differences between VKA and DOAC were statistically significant for all efficacy outcomes and at most adherence levels. CONCLUSIONS: Even small reductions in OAC adherence in patients with atrial fibrillation were associated with significant increases in risk of stroke, with greater magnitudes for DOAC than VKA. DOAC recipients may be more vulnerable than VKA recipients to increased risk of stroke and death even with small reductions in adherence. The worsening efficacy outcomes associated with decreasing adherence occurred without the benefit of major bleeding reduction.

Clinical characteristics and prognostic importance of anticoagulant use in ischemic left ventricular aneurysm: a retrospective cohort study.

There is insufficient data on systemic embolic events (SSEs) in patients with ischemic left ventricular aneurysm (LVA) concerning the impact of anticoagulation therapy. In this retrospective cohort study with 1043 patients with ischemic LVA, SSEs occurred in 7.2% over 2.4 years. After adjusting for relevant factors, the use of anticoagulants was independently associated with a lower incidence of SSE (3.1% vs. 9.0%, P < 0.001; subdistribution hazard ratios (SHR) 0.21, 95% confidence intervals (CI) 0.10-0.44, P < 0.001), with no significant difference in net adverse clinical events (NACEs) (10.6% vs. 13.3%, P = 0.225). Specifically, anticoagulation in patients with apical segment akinesis significantly reduced SSEs (3.9% vs. 13.6%, P = 0.002) and NACE rates (7.8% vs. 19.4%, P = 0.002). Major bleeding rates did not significantly differ between groups (5.6% vs. 3.5%, P = 0.111). These findings highlight the SSE risk in ischemic LVA and suggest potential benefits of anticoagulation, particularly in those with apical segment akinesis. These findings need to be validated in independent datasets.

[Application of Photoplethysmography Combined with Deep Learning in Postoperative Monitoring of Flaps].

Objective: Photoelectric volumetric tracing (PPG) exhibits high sensitivity and specificity in flap monitoring. Deep learning (DL) is capable of automatically and robustly extracting features from raw data. In this study, we propose combining PPG with 1D convolutional neural networks (1D-CNN) to preliminarily explore the method's ability to distinguish the degree of embolism and to localize the embolic site in skin flap arteries. Methods: Data were collected under normal conditions and various embolic scenarios by creating vascular emboli in a dermatome artery model and a rabbit dermatome model. These datasets were then trained, validated, and tested using 1D-CNN. Results: As the degree of arterial embolization increased, the PPG amplitude upstream of the embolization site progressively increased, while the downstream amplitude progressively decreased, and the gap between the upstream and downstream amplitudes at the embolization site progressively widened. 1D-CNN was evaluated in the skin flap arterial model and rabbit skin flap model, achieving average accuracies of 98.36% and 95.90%, respectively. Conclusion: The combined monitoring approach of DL and PPG can effectively identify the degree of embolism and locate the embolic site within the skin flap artery.

Risk of Major Bleeding, Stroke/Systemic Embolism, and Death Associated With Different Oral Anticoagulants in Patients With Atrial Fibrillation and Severe Chronic Kidney Disease.

BACKGROUND: Patients with atrial fibrillation and severe chronic kidney disease have higher risks of bleeding, thromboembolism, and mortality. However, optimal anticoagulant choice in these high-risk patients remains unclear. METHODS AND RESULTS: Using deidentified electronic health records from the Optum Labs Data Warehouse, adults with atrial fibrillation and severe chronic kidney disease (estimated glomerular filtration rate <30 mL/min per 1.73 m2) initiating warfarin, apixaban, or rivaroxaban between 2011 and 2021 were included. Using inverse probability of treatment weighting, adjusted risks of major bleeding, stroke/systemic embolism, and death were compared among agents. A total of 6794 patients were included (mean age, 78.5 years; mean estimated glomerular filtration rate, 24.7 mL/min per 1.73 m2; 51% women). Apixaban versus warfarin was associated with a lower risk of major bleeding (incidence rate, 1.5 versus 2.9 per 100 person-years; subdistribution hazard ratio [sub-HR], 0.53 [95% CI, 0.39-0.70]), and similar risks for stroke/systemic embolism (incidence rate, 1.9 versus 2.4 per 100 person-years; sub-HR, 0.80 [95% CI, 0.59-1.09]) and death (incidence rate, 4.6 versus 4.5 per 100 person-years; HR, 1.03 [95% CI, 0.82-1.29]). Rivaroxaban versus warfarin was associated with a higher risk of major bleeding (incidence rate, 4.9 versus 2.9 per 100 person-years; sub-HR, 1.65 [95% CI, 1.10-2.48]), with no difference in risks for stroke/systemic embolism and death. Apixaban versus rivaroxaban was associated with a lower risk of major bleeding (sub-HR, 0.53 [95% CI, 0.36-0.78]). CONCLUSIONS: These real-world findings are consistent with potential safety advantages of apixaban over warfarin and rivaroxaban for patients with atrial fibrillation and severe chronic kidney disease. Further randomized trials comparing individual oral anticoagulants are warranted.

A hyper-viscoelastic uniaxial characterization of collagenous embolus analogs in acute ischemic stroke.

PURPOSE: Acute ischemic stroke is a leading cause of death and morbidity worldwide. Despite advances in medical technology, nearly 30% of strokes result in incomplete vessel recanalization. Recent studies have demonstrated that clot composition correlates with success rates of mechanical thrombectomy procedures. To understand clot behavior during thrombectomy, which exerts considerable strains on thrombi, in vitro studies must characterize the rate-dependent high-strain behavior of embolus analogs (EAs) with different formation conditions, which can be used to fit models of hyper-viscoelasticity. METHODS: In this study, the effect of collagen infiltration as a carotid-induced collagen-rich thrombosis surrogate is considered as a contributor to embolus analog high-strain stiffness, when compared to 40% hematocrit EAs. RESULTS: EA high-strain stiffnesses, characterized on a uniaxial load frame, increase by an order of magnitude for collagenous clot analogs. Chandler loop analogs show high-strain stiffnesses and clot compositions commensurate with previous reports of stroke patient clots, and collagenous clots show significant increase in stiffness when compared to stroke patient clots. Finally, hyper-viscoelastic curve fitting demonstrates the asymmetry between tension and compression. Nonlinear, rate-dependent models that consider clot-stiffening behavior match the high strain stiffness of clots fairly well. Furthermore, we demonstrate that the stability of the elastic energy needs to be considered to obtain optimal curve fits for high-strain, rate dependent data. CONCLUSION: This study provides a framework for the development of dynamically formed EAs that mimic the mechanical and structural properties of in vivo clots and provides parameters for numerical simulation of clot behavior with hyper-viscoelastic models.

A Multidisciplinary Approach to Staphylococcus aureus Triple-Valve Infective Endocarditis With Multi-Organ Involvement.

Multivalvular endocarditis is a rare and potentially fatal complication that can occur in people who inject drugs. Currently, there are few cases that have been studied or reported in literature. A complication of this manifestation that worsens prognosis and treatment is the distribution of septic emboli throughout the body which highlights the dissemination of the infection. There are no specific guidelines on the treatment of multivalvular endocarditis, but its complexity can present challenges in administering medical and surgical treatment. In this case of a 37-year-old man with infective endocarditis of 3 valves, a comprehensive work-up found septic emboli in the lungs, kidneys, ribs, spine, and brain with ophthalmologic involvement that resulted in visual impairment. This case highlights important complications that can occur with septic emboli and management of these issues using a multidisciplinary approach including the treatment of substance use disorder.

[Surgery for a Missile Embolus in the Right Ventricle].

Ballistic embolism represents an unusual complication of vascular by a flying object injury. Because embolus is remote from injury site, the occurrence of missile embolus may be overlooked and lead to delay in diagnosis of significant ischemia or embolism. We herein report a successful surgical removal of a rare missile embolus from the upper arm in the right ventricle. A 44-year-old man visited our hospital because of pulsatile bleeding from the left upper arm due to injury by a flying metal fragment of a hammerhead. Chest roentgenogram and computed tomography (CT) scan 9 days after the injury demonstrated a missile embolus in the right ventricle, which was thought to be ballistic embolism of the metal fragment. We underwent surgical removal of the retained object under cardiopulmonary bypass uneventfully, and discharged home ten days later.

Comparative Effectiveness and Safety of Apixaban, Rivaroxaban, and Warfarin in Patients With Cirrhosis and Atrial Fibrillation : A Nationwide Cohort Study.

BACKGROUND: Apixaban, rivaroxaban, and warfarin have shown benefit for preventing major ischemic events, albeit with increased bleeding risk, among patients in the general population with atrial fibrillation (AF). However, data are scarce in patients with cirrhosis and AF. OBJECTIVE: To compare the effectiveness and safety of apixaban versus rivaroxaban and versus warfarin in patients with cirrhosis and AF. DESIGN: Population-based cohort study. SETTING: Two U.S. claims data sets (Medicare and Optum's de-identified Clinformatics Data Mart Database [2013 to 2022]). PARTICIPANTS: 1:1 propensity score (PS)-matched patients with cirrhosis and nonvalvular AF initiating use of apixaban, rivaroxaban, or warfarin. MEASUREMENTS: Primary outcomes included ischemic stroke or systemic embolism and major hemorrhage (intracranial hemorrhage or major gastrointestinal bleeding). Database-specific and pooled PS-matched rate differences (RDs) per 1000 person-years (PY) and Cox proportional hazard ratios (HRs) with 95% CIs were estimated, controlling for 104 preexposure covariates. RESULTS: Rivaroxaban initiators had significantly higher rates of major hemorrhagic events than apixaban initiators (RD, 33.1 per 1000 PY [95% CI, 12.9 to 53.2 per 1000 PY]; HR, 1.47 [CI, 1.11 to 1.94]) but no significant differences in rates of ischemic events or death. Consistently higher rates of major hemorrhage were found with rivaroxaban across subgroup and sensitivity analyses. Warfarin initiators also had significantly higher rates of major hemorrhage than apixaban initiators (RD, 26.1 per 1000 PY [CI, 6.8 to 45.3 per 1000 PY]; HR, 1.38 [CI, 1.03 to 1.84]), particularly hemorrhagic stroke (RD, 9.7 per 1000 PY [CI, 2.2 to 17.2 per 1000 PY]; HR, 2.85 [CI, 1.24 to 6.59]). LIMITATION: Nonrandomized treatment selection. CONCLUSION: Among patients with cirrhosis and nonvalvular AF, initiators of rivaroxaban versus apixaban had significantly higher rates of major hemorrhage and similar rates of ischemic events and death. Initiation of warfarin versus apixaban also contributed to significantly higher rates of major hemorrhagic events, including hemorrhagic stroke. PRIMARY FUNDING SOURCE: National Institutes of Health.

Vertebral body and spinal cord infarction in a pile-driver operator with fibrocartilaginous disc embolism.

We describe the case of a male heavy machinery operator who presented from work with a rapidly evolving spinal cord syndrome. Spinal MRI revealed thoracic vertebral body and cord infarction and evolving mild disc prolapse attributed to fibrocartilaginous disc embolism (FCDE). FCDE should be considered as one of the aetiological mechanisms of acute spinal cord infarction in pile-driver/heavy machinery operators, especially in association with adjacent vertebral body infarction and intervertebral disc prolapse. Magnetic resonance imaging (MRI) changes may evolve, warranting early follow-up MRI in appropriate cases.

Formation of a Pseudoaneurysm after a .22 Caliber Bullet Embolized to the Left Femoral Artery: A Case Report.

Bullet embolization is a rare and potentially life-threatening complication of gunshot wounds, particularly in lowpowered and small-caliber bullets. When these small bullets enter a large elastic vessel, they have the potential to leave a small entrance hole that can form a traumatic pseudoaneurysm. These pseudoaneurysms, which may be life-protecting at first, may rupture and lead to exsanguination if not found. We report an interesting case of an 18-year-old male gunshot victim where a bullet formed an aortic pseudoaneurysm and subsequently embolized and present a review of the literature regarding bullet embolization and traumatic pseudoaneurysms.

Early surgery to prevent embolic events in patients with infective endocarditis: a comprehensive review.

BACKGROUND: Infective endocarditis (IE) is a dangerous and lethal illness with high mortality rates. One of the main indications for surgery according to the guidelines is prevention of embolic events. However, uncertainty remains concerning the timing of surgery and the effect of early surgery in combination with antibiotic therapy versus antibiotic therapy alone in IE patients with a vegetation size > 10 mm. METHODS: We conducted a comprehensive review by searching the PubMed, MEDLINE, and EMbase databases. Titles and abstracts were screened, and studies of interest were selected for full-text assessment. Studies were selected for review if they met the criteria of comparing surgical treatment + antibiotic therapy to antibiotic therapy alone in patients with vegetations > 10 mm. RESULTS: We found 1,503 studies through our database search; nine of these were eligible for review, with a total number of 3,565 patients. Median age was 66 years (range: 17-80) and the median percentage of male patients was 65.6% (range: 61.8 - 71.4%). There was one randomised controlled trial, one prospective study, and seven retrospective studies. Seven studies found surgery + antibiotic therapy to be associated with better outcomes in patients with IE and vegetations > 10 mm, one of them being the randomised trial [hazard ratio = 0.10; 95% confidence interval 0.01-0.82]. Two studies found surgery + antibiotic therapy was associated with poorer outcomes compared with antibiotic therapy alone. CONCLUSION: Overall, data vary in quality due to low numbers and selection bias. Evidence is conflicting, yet suggest that surgery + antibiotic therapy is associated with better outcomes in patients with IE and vegetations > 10 mm for prevention of emboli. Properly powered randomised trials are warranted.

Comparison of embolic risk in left ventricular thrombus between nonischemic and ischemic cardiomyopathy: A nationwide database analysis.

BACKGROUND: Left ventricular (LV) thrombus is not common but poses significant risks of embolic stroke or systemic embolism. However, the distinction in embolic risk between nonischemic cardiomyopathy (NICM) and ischemic cardiomyopathy (ICM) remains unclear. METHODS AND RESULTS: In total, 2738 LV thrombus patients from the JROAD-DPC (Japanese Registry of All Cardiac and Vascular Diseases Diagnosis Procedure Combination) database were included. Among these patients, 1037 patients were analyzed, with 826 (79.7%) having ICM and 211 with NICM (20.3%). Within the NICM group, the distribution was as follows: dilated cardiomyopathy (DCM; 41.2%), takotsubo cardiomyopathy (27.0%), hypertrophic cardiomyopathy (18.0%), and other causes (13.8%). The primary outcome was a composite of embolic stroke or systemic embolism (SSE) during hospitalization. The ICM and NICM groups showed no significant difference in the primary outcome (5.8% vs. 7.6%, p = 0.34). Among NICM, SSE occurred in 12.6% of patients with DCM, 7.0% with takotsubo cardiomyopathy, and 2.6% with hypertrophic cardiomyopathy. Multivariate logistic regression analysis for SSE revealed an odds ratio of 1.4 (95% confidence interval [CI], 0.7-2.7, p = 0.37) for NICM compared to ICM. However, DCM exhibited a higher adjusted odds ratio for SSE compared to ICM (2.6, 95% CI 1.2-6.0, p = 0.022). CONCLUSIONS: This nationwide shows comparable rates of embolic events between ICM and NICM in LV thrombus patients, with DCM posing a greater risk of SSE than ICM. The findings emphasize the importance of assessing the specific cause of heart disease in NICM, within LV thrombus management strategies.

Investigation of cardiopulmonary bypass parameters on embolus transport in a patient-specific aorta.

Neurological complexities resulting from surgery requiring cardiopulmonary bypass (CPB) remain a major concern, encompassing a spectrum of complications including thromboembolic stroke and various cognitive impairments. Surgical manipulation during CPB is considered the primary cause of these neurological complications. This study addresses the overall lack of knowledge concerning CPB hemodynamics within the aorta, employing a combined experimental-computational modeling approach, featuring computational fluid dynamics simulations validated with an in vitro CPB flow loop under steady conditions. Parametric studies were systematically performed, varying parameters associated with CPB techniques (pump flow rate and hemodiluted blood viscosity) and properties related to formed emboli (size and density). This represents the first comprehensive investigation into the individual and combined effects of these factors. Our findings reveal critical insights into the operating conditions of CPB, indicating a positive correlation between pump flow rate and emboli transport into the aortic branches, potentially increasing the risk of stroke. It was also found that larger emboli were more often transported into the aortic branches at higher pump flow rates, while smaller emboli preferred lower flow rates. Further, as blood is commonly diluted during CPB to decrease its viscosity, more emboli were found to enter the aortic branches with greater hemodilution. The combined effects of these parameters are captured using the non-dimensional Stokes number, which was found to positively correlate with emboli transport into the aortic branches. These findings contribute to our understanding of embolic stroke risk factors during CPB and shed light on the complex interplay between CPB parameters.