Clot Volume Research Articles

Integration of clotting and fibrinolysis: central role of platelets and factor XIIIa.

The aim of the present study was to establish the role of platelets and activated factor XIIIa (FXIIIa) in the structuring of the fibrin network as well as to clarify the effect of network compaction on clot lysis. Turbidimetry was used for the one-stage clotting test where platelet-free plasma (PFP) is regarded as single factor-deficient plasma (platelets as lacking factor) and autologous platelet-rich plasma (PRP) as deficiency corrected plasma. Structural features of the developed and subsequently lysed fibrin network, formed under static and flow conditions, were visualized by confocal microscopy. Thrombin-initiated plasma clotting revealed changes in the shape of the absorption curve, more pronounced in the presence of platelets. These changes correlate with the transformation of the fibrin scaffold during clot maturing. With the combined action of platelets, thrombin and Ca2+, plasma clotting passes through two phases: initial formation of a platelet-fibrin network (first peak in the polymerization curve), and then the compaction of fibrin, driven by FXIIIa (the second peak) which can be further modulate by the contractile action of platelets. These structural changes, mediated by platelets and FXIIIa, have been shown to determine subsequent clot lysis. Platelet aggregates serve as organizing centers that determine the distribution of fibrin in clot volume. The openwork structure of the platelet-transformed fibrin provides the necessary prerequisites for its timely lysis. The revealed aspects of the interaction of platelets and FXIIIa, which accompanies the maturation of a fibrin clot, may lead to new approaches in the pharmacological correction of disorders associated with both thrombotic episodes and bleeding tendency.

Clinical Characteristics and Outcome of Spontaneous Intracerebral Hemorrhage

Background: Stroke is the second leading cause of death and disability globally. Intracerebral hemorrhage represents a prominent subtype comprising 10-20% of all strokes and posing substantial challenges, particularly in low-income countries. This study aims to unravel the clinical profile and outcomes of spontaneous ICH patients at our institute. Materials and Methods: This is a prospective observational study conducted at the department of Neurosurgery Nobel Medical College Teaching Hospital, Biratnagar, Nepal over a period of one and half years. Results: In the Present study, a total of 285 populations were studied, where there was male preponderance with the mean age of 57.9 years. Commonest clinical manifestation was sudden onset headache (75.1%) followed by decreased level of consciousness. Hypertension was the commonest cause of ICH. Basal ganglia were the primary location of bleed. The statistical analysis revealed a significant difference in the mean clot volume between survivors and non-survivors. There was a strong association between ventricular extension of hematoma and outcome. Surgical hematoma evacuation was performed in 30.9% of cases. Favorable outcomes, defined by a modified Rankin Scale score of 0-3, were achieved in 58.9% of participants. Conclusion: Age, sudden onset headache, and hypertension predict mortality in primary intracerebral hemorrhage (ICH), particularly with advanced age linked to poorer outcomes. A Glasgow Coma Score less than eight increases mortality risk, while clot volume and intraventricular extension play crucial roles in ICH outcome.

NnU-Net-based deep-learning for pulmonary embolism: detection, clot volume quantification, and severity correlation in the RSPECT dataset

ObjectivesCT pulmonary angiography is the gold standard for diagnosing pulmonary embolism, and DL algorithms are being developed to manage the increase in demand. The nnU-Net is a new auto-adaptive DL framework that minimizes manual tuning, making it easier to develop effective algorithms for medical imaging even without specific expertise.This study assesses the performance of a locally developed nnU-Net algorithm on the RSPECT dataset for PE detection, clot volume measurement, and correlation with right ventricle overload. Materials & MethodsUser input was limited to segmentation using 3DSlicer. We worked with the RSPECT dataset and trained an algorithm from 205 PE and 340 negatives. The test dataset comprised 6573 exams. Performance was tested against PE characteristics, such as central, non-central, and RV overload. Blood clot volume (BCV) was extracted from each exam. We employed ROC curves and logistic regression for statistical validation. ResultsNegative studies had a median BCV of 1 μL, which increased to 345 μL in PE-positive cases and 7,378 μL in central PEs. Statistical analysis confirmed a significant BCV correlation with PE presence, central PE, and increased RV/LV ratio (p < 0.0001). The model’s AUC for PE detection was 0.865, with an 83 % accuracy at a 55 μL threshold. Central PE detection AUC was 0.937 with 91 % accuracy at 850 μL. The RV overload AUC stood at 0.848 with 79 % accuracy. ConclusionThe nnU-Net algorithm demonstrated accurate PE detection, particularly for central PE. BCV is an accurate metric for automated severity stratification and case prioritization. Clinical relevance statementThe nnU-Net framework can be utilized to create a dependable DL for detecting PE. It offers a user-friendly approach to those lacking expertise in AI and rapidly extracts the Blood Clot Volume, a metric that can evaluate the PE’s severity.

Computer based visualization of clot structures in extracorporeal membrane oxygenation and histological clot investigations for understanding thrombosis in membrane lungs.

Extracorporeal membrane oxygenation (ECMO) was established as a treatment for severe cardiac or respiratory disease. Intra-device clot formation is a common risk. This is based on complex coagulation phenomena which are not yet sufficiently understood. The objective was the development and validation of a methodology to capture the key properties of clots deposed in membrane lungs (MLs), such as clot size, distribution, burden, and composition. One end-of-therapy PLS ML was examined. Clot detection was performed using multidetector computed tomography (MDCT), microcomputed tomography (μCT), and photography of fiber mats (fiber mat imaging, FMI). Histological staining was conducted for von Willebrand factor (vWF), platelets (CD42b, CD62P), fibrin, and nucleated cells (4', 6-diamidino-2-phenylindole, DAPI). The three imaging methods showed similar clot distribution inside the ML. Independent of the imaging method, clot loading was detected predominantly in the inlet chamber of the ML. The μCT had the highest accuracy. However, it was more expensive and time consuming than MDCT or FMI. The MDCT detected the clots with low scanning time. Due to its lower resolution, it only showed clotted areas but not the exact shape of clot structures. FMI represented the simplest variant, requiring little effort and resources. FMI allowed clot localization and calculation of clot volume. Histological evaluation indicated omnipresent immunological deposits throughout the ML. Visually clot-free areas were covered with leukocytes and platelets forming platelet-leukocyte aggregates (PLAs). Cells were embedded in vWF cobwebs, while vWF fibers were negligible. In conclusion, the presented methodology allowed adequate clot identification and histological classification of possible thrombosis markers such as PLAs.

Effect of a 3-Month Single-Drug Approach Using Rivaroxaban for Symptomatic Proximal Deep Vein Thrombosis.

Background: Factor Xa inhibitors, such as rivaroxaban, are increasing the convenience of treatment for deep vein thrombosis (DVT). Limited evidence exists regarding clot evaluation at 3 months after treatment for DVT. Methods and Results: We retrospectively analyzed the clinical course of symptomatic proximal DVT in patients who received 3 months of anticoagulation treatment at our hospital. Patients treated with the rivaroxaban single-drug approach were classified as group A (n=42). Patients treated with unfractionated heparin (UFH) or subcutaneous fondaparinux followed by vitamin K antagonist comprised group B (n=60) as an historical cohort. The quantitative ultrasound thrombosis (QUT) score was used to quantify clot burden before and after treatment. No significant differences were observed in patient characteristics between the groups. Serum D-dimer levels in both groups significantly improved after treatment. Clot volume assessed using QUT also reduced significantly in both groups. The QUT score in groups A and B improved from 7.5 [4.8, 12.0] to 3.0 [1.8, 5.0; P=0.000] and 7.0 [4.0, 9.8] to 3.0 [2.0, 5.0; P=0.000], respectively. The change in QUT (∆QUT) was significantly greater in group A compared with group B (-4.5 [-8.25, -2.0] vs. -2.0 [-6.0, 0.0]; P=0.005). Conclusions: We were able to demonstrate the effectiveness of DVT treatment using rivaroxaban over a period of 3 months from onset, in terms of clot regression evaluated using the QUT score.

Pulmonary hemorrhage in oncologic patients – a diagnostic algorithm

The OBJECTIVE was to develop a diagnostic algorithm in oncologic patients with pulmonary hemorrhage.METHODS AND MATERIAL. A retrospective single-center study of the medical records of 258 patients who met the inclusion criteria was conducted. Inclusion criteria: age over 18 years, oncologic disease of the chest organs complicated by pulmonary hemorrhage. Inclusion criteria: age over 18 years, oncologic disease of the chest organs complicated by pulmonary hemorrhage. Exclusion criteria: age under 18 years, pulmonary hemorrhage of non-oncologic etiology. Pulmonary hemorrhage was considered to be the discharge of any volume of fresh blood or clots from the tracheobronchial tree, which was determined on the basis of anamnesis, clinical manifestations in the hospital, endoscopic examination. Routine diagnostic methods of investigation, such as chest radiography, chest computed tomography (including with contrast enhancement), fibrotracheobronchoscopy, bronchial arteriography were evaluated.RESULTS. The sensitivity for diagnosing the oncologic process in chest radiography, computed tomography, and fibrotracheobronchoscopy, was 84.7 %, 98.4 %, and 94.4 %, respectively. The sensitivity of fibrotracheobronchoscopy to detect the bleeding itself in oncologic patients reached 31.3 %, and the sensitivity of bronchial arteriography to diagnose the source of bleeding was 87.7 %.CONCLUSION. In pulmonary hemorrhage of oncologic genesis, the combination of fibrotracheobronchoscopy with computed tomography has sensitivity in 100 % of cases in determining the source and localization of the pathological process. Bronchial arteriography allows to perform endovascular hemostasis. It is necessary to conduct multicenter studies in order to develop and implement a unified algorithm assessing all etiopathogenetic features of pulmonary hemorrhage in oncologic patients.

Spontaneous intracerebral hemorrhage: a review of the prevalence, trigger factors, therapeutic and surgical treatment

Spontaneous intracerebral hemorrhage is the second most common subtype of stroke and is a significant cause of mortality and morbidity worldwide. Trigger factors that “accelerate” disease onset may include hypertension, excessive alcohol consumption, constant smoking, hypocholesterolemia, medications, male sex, advanced age, living in an underdeveloped country, ethnicity, chronic kidney disease, cerebral amyloid angiopathy, and microhemorrhages. Therapeutic solutions for spontaneous intracerebral hemorrhage aimed at stopping the progression of hemorrhage, reducing the clot volume of intraventricular and parenchymal hematoma, combating perihematomal edema and inflammation, rapidly reducing blood pressure, and providing hemostatic therapy with transfusion of platelets and other coagulation complexes. Clinical trials on minimally invasive methods of surgical evacuation (endoscopic surgery, stereotactic aspiration, and invasive craniopuncture) are ongoing and may provide positive results because of the shorter operation time and use of local anesthesia. Minimally invasive surgery methods can theoretically improve the outcomes of open surgery by reducing damage to collateral tissues and reducing anesthesia time; however, they cannot be a full-fledged alternative.

The effect of actuation frequency on clot integration with the Tigertriever device: A preliminary in vitro study.

The Tigertriever stent retriever (Rapid Medical) can be actively expanded and contracted by the operator, which allows for several actuation-related parameters to be optimized to potentially improve device efficacy. These parameters have not yet been evaluated. We conducted a benchtop study to evaluate the effect of actuation frequency on clot integration within the stent. A Tigertriever 17 device was deployed within a biological clot analog placed in a straight tube. The device was actuated between the maximally contracted and maximally expanded states with three different frequencies: passive (one-time opening, n = 6), slow (20 s/cycle, n = 6), and fast (5 s/cycle, n = 7). A flat-detector CT scan was acquired, the clot and stent wires were segmented, and the boundaries of the clot and stent wires were calculated on each axial slice. The intersection between the stent and clot boundaries throughout the volume was defined as the volume of clot integrated within the stent. The clot integration factor (ratio of integrated clot volume to total clot volume) was then statistically compared between the three frequencies as an estimate of clot capture efficiency. The clot integration factor was significantly higher (23% increase, p = 0.01) with the fast actuation as compared to the passive and slow actuations, with a post hoc test showing no difference (p > 0.05) between the passive and slow groups. Faster actuation frequencies may result in improved clot integration with the Tigertriever device. This effect needs to be validated by clinical data.

Dynamic Perviousness Predicts Revascularization Success in Acute Ischemic Stroke.

The predictive value of thrombus perviousness in acute ischemic stroke (AIS), as measured by computed tomography (CT), has been intensively studied with conflicting results. In this study, we investigate the predictive potential of the novel concept of dynamic perviousness using three-dimensional (3D) volumetric evaluation of occlusive thrombi. The full thrombus volume in 65 patients with a hyperdense artery sign on non-contrast CT (NCCT), who underwent mechanical thrombectomy (MT), was segmented. Perviousness maps were computed voxel-wise for the entire thrombus volume as thrombus attenuation increase (TAI) between NCCT and CT angiography (CTA) as well as between CTA and late venous phase CT (CTV). Perviousness was analyzed for its association with NIHSS at admission, Thrombolysis In Cerebral Infarction (TICI) score, and number of MT passes. The mean late-uptake TAI of thrombi with NIHSS scores greater than 21 at admission was approximately 100% higher than for lower scored NIHSS (p between 0.05 and 0.005). Concerning revascularization results, thrombi requiring less than four MT passes had ca. 80% higher group mean late-uptake TAI than clots requiring four or more passes (p = 0.03), and thrombi with TICI score III had ca. 95% higher group mean late-uptake TAI than thrombi with TICI II (p = 0.03). Standard perviousness showed no significant correlation with MT results. Standard thrombus perviousness of 3D clot volume is not associated with revascularization results in AIS. In contrast, dynamic perviousness assessed with a voxel-wise characterization of 3D thrombi volume may be a better predictor of MT outcomes than standard perviousness.

The effect of off-label use of reduced-dose direct oral anticoagulants therapy in the treatment of pulmonary embolism comparable to standard-dose therapy

Direct oral anticoagulants (DOACs) have been shown to be effective and safe in preventing pulmonary embolism recurrence. In this single-center retrospective observational study, we aimed to evaluate the efficacy and safety of reduced-dose DOACs in 86 consecutive patients with acute pulmonary embolism. Patients were divided into standard-dose and reduced-dose DOACs groups. Initial clot volume did not significantly differ between the two groups (standard-dose DOACs vs. reduced-dose DOACs, 18.8 [Q1–Q3 7.3–30.8] mL vs. 10.0 [Q1–Q3 3.2–27.9] mL, p = 0.1). Follow-up computed tomography (CT) within 30 days showed a higher rate of clot volume reduction or disappearance in the standard-dose group compared to the reduced-dose group (standard-dose DOACs vs. reduced-dose DOACs, 81.6% vs. 53.9%, p = 0.02). However, at the final follow-up CT, there was no significant difference in clot volume change between the two groups (standard-dose DOACs vs. reduced-dose DOACs, 91.5% vs. 82.0%, p = 0.19). Major bleeding occurred in two patients in the standard-dose group (4.3%) and three patients in the reduced-dose DOACs group (7.7%) (p = 0.5). In conclusion, while standard-dose DOACs demonstrated superior efficacy in early clot reduction, reduced doses of apixaban and edoxaban showed comparable efficacy and safety profiles in long-term treatment of acute pulmonary embolism in certain patients.

Abstract WP302: Different Clot Characteristics According to the Clot Volume: A Microscopic Analysis of Clot Composition

Background and Objectives: Understanding the mechanisms of thrombosis is crucial for the future advancement in treating ischemic stroke. While many researches on thrombogenesis have been conducted, there was a limited data on thrombus growth. In this study, we investigated whether the clot composition or clot characteristics differed by the clot size using microscopic analysis of ischemic clot. Methods: We obtained the clots from 238 ischemic stroke patients who received endovascular treatment between July 2017 and July 2023 at Severance Stroke Center. We quantitatively analysed the clot components identified using immunohistochemistry. The fractions of each component such as fibrin, red blood cells (RBC), and platelets were calculated as the percentage pixel density of the total clot area. Clot volume was semiautomatically measured on thin-section computed tomography performed at stroke presentation using software. We determined the association between clot volume and histopathologic composition, arrangement patterns, and clinical or radiological features. Results: Among the 238 patients, the median (interquartile) of clot volume was 47.0 mm 3 (range 23.8-79.8). As the clot volume increased, the proportion of RBC became larger (r = 0.307. P &lt;0.001) and the proportion of platelet became smaller (r = -0.150, p=0.029). In terms of RBC patterns, purely aggregated RBC patterns, rather than RBC-fibrin mixture patterns, was positively associated with the clot volume. After adjusting for potential confounders including posterior circulation occlusion, serum hemoglobin levels, serum albumin levels, and the presence of active cancer (all p&lt;0.05 in univariable analysis), clot volume was independently related with the proportion of RBC (ß 0.726, SE 0.302, p =0.017) or the presence of purely aggregated RBC pattern (ß 59.182, SE 11.684, p &lt;0.001). Conclusions: As the clot volume increased, the proportion of RBCs increases, and areas of purely packed with RBCs become larger. These findings suggest that as the clot grows, RBC mainly involved the clot volume growth.

A Quantitative Method for the Evaluation of Deep Vein Thrombosis in a Murine Model Using Three-Dimensional Ultrasound Imaging.

Deep vein thrombosis (DVT) is a life-threatening condition that can lead to its sequelae pulmonary embolism (PE) or post-thrombotic syndrome (PTS). Murine models of DVT are frequently used in early-stage disease research and to assess potential therapies. This creates the need for the reliable and easy quantification of blood clots. In this paper, we present a novel high-frequency 3D ultrasound approach for the quantitative evaluation of the volume of DVT in an in vitro model and an in vivo murine model. The proposed method involves the use of a high-resolution ultrasound acquisition system and semiautomatic segmentation of the clot. The measured 3D volume of blood clots was validated to be correlated with in vitro blood clot weights with an R2 of 0.89. Additionally, the method was confirmed with an R2 of 0.91 in the in vivo mouse model with a cylindrical volume from macroscopic measurement. We anticipate that the proposed method will be useful in pharmacological or therapeutic studies in murine models of DVT.

Clot ratio, new clot burden score with deep learning, correlates with the risk stratification of patients with acute pulmonary embolism.

Risk stratification for patients with acute pulmonary embolism (APE) is significantly important for treatment and prognosis evaluation. We aimed to develop a novel clot burden score on computed tomography pulmonary angiography (CTPA) based on deep learning (DL) algorithm for risk stratification of APE. The study retrospectively enrolled patients newly diagnosed with APE in China-Japan Friendship Hospital consecutively. We collected baseline data and CTPA parameters, and calculated four different clot burden scores, including Qanadli score, Mastora score, clot volume and clot ratio. The former two were calculated by two radiologists separately, while clot volume and clot ratio were based on the DL algorithm. The area under the curve (AUC) of four clot burden scores were analyzed. Seventy patients were enrolled, including 17 in high-/intermediate-high risk and 53 in low-/intermediate-low risk. Clot burden was related to the risk stratification of APE. Among four clot burden scores, clot ratio had the highest AUC (0.719, 95% CI: 0.569-0.868) to predict patients with higher risk. In the patients with hemodynamically stable APE, only clot ratio presented statistical difference (P=0.046). Clot ratio is a new imaging marker of clot burden which correlates with the risk stratification of patients with APE. Higher clot ratio may indicate higher risk and acute right ventricular dysfunction in patients with hemodynamically stable status.

Abstract 244: Effect of Actuation Frequency on Clot Integration with the Tigertriever Device: An In Vitro Study

Introduction Mechanical thrombectomy has been widely recognized as the preferred treatment for large vessel occlusion strokes. The Tigertriever stent‐retriever (Rapid Medical, Yokneam, Israel) is a novel operator‐adjustable device that can be actively expanded and contracted by the operator [1], which allows for several actuation‐related parameters to be optimized to potentially improve device efficacy. These parameters – such as amplitude and frequency of the actuation cycle, and rate of expansion and contraction – have not yet been evaluated in correlation with device success. We conducted a benchtop study to evaluate the effect of actuation frequency on clot integration within the stent. Methods A Tigertriever 17 device was deployed within a biological thrombus analog (2.5 cm length) placed in a straight silicone tube (2.4 mm diameter). The device was actuated between the maximally contracted and maximally expanded states with three different frequencies: Passive (one‐time opening, n=6), Slow (20 seconds/cycle, n=6), and Fast (5 seconds/cycle, n=7). A flat‐detector CT scan was acquired, the clot and stent wires were segmented, and the boundaries of the clot and stent wires were calculated on each axial slice (Figure 1A). The intersection between the stent and clot boundaries throughout the volume was defined as the volume of clot integrated within the stent. The clot integration factor (CIF, ratio of integrated clot volume to total clot volume) was then statistically compared between the three frequencies as an estimate of clot capture efficiency. Results The CIF was significantly higher (23% increase, p=0.01) with the Fast actuation as compared to the Passive and Slow actuations, with a post‐hoc test showing no difference (p&gt;0.05) between the Passive and Slow actuation frequency (Figure 1B). Conclusion The unique malleability of the Tigertriever stent‐retriever (Rapid Medical) presents an opportunity to better understand actuation parameters that can maximize thrombus capture. Results indicate that faster actuation frequencies may result in improved clot integration with the Tigertriever device. These results are concordant with a previous clinical study [1] that found repetitive‐expansion‐contraction was more successful than single unsheathing (which corresponds to our Passive group). It is possible that the greater acceleration of the stent mesh wires in the Fast actuation frequency resulted in increased radial forces that improved clot integration. This effect must be further validated in an in vitro setting more representative of physiological conditions, as well as eventual clinical evaluation.

Assessment of effectiveness and safety of thrombolytic therapy to pulmonary emboli by endobronchial ultrasound-guided transbronchial needle injection

ObjectiveEndobronchial ultrasound–guided transbronchial needle injection (EBUS-TBNI) may effectively treat acute pulmonary embolisms (PEs). Here, we assessed the effectiveness of clot dissolution and safety of tissue plasminogen activator (t-PA) injection using EBUS-TBNI in a 1-week survival study of a porcine PE model. MethodsSix pigs with bilateral PEs were used: 3 for t-PA injection using EBUS-TBNI (TBNI group) and 3 for systemic administration of t-PA (systemic group). Once bilateral PEs were created, each 25 mg of t-PA injection using EBUS-TBNI for bilateral PEs (a total of 50 mg t-PA) and 100 mg of t-PA systemic administration was performed on day 1. Hemodynamic parameters, blood tests, and contrast-enhanced computed tomography scans were carried out at several time points. On day 7, pigs were humanely killed to evaluate the residual clot volume in the pulmonary arteries. ResultsThe average of percent change of residual clot volumes was significantly lower in the TBNI group than in the systemic group (%: systemic group 36.6 ± 22.6 vs TBNI group 9.6 ± 6.1, P < .01) on day 3. Considering the elapsed time, the average decrease of clot volume per hour at pre-t-PA to post t-PA was significantly greater in the TBNI group than in the systemic group (mm3/hour: systemic 68.1 ± 68.1 vs TBNI 256.8 ± 148.1, P < .05). No hemorrhage was observed intracranially, intrathoracically, or intraperitoneally on any contrast-enhanced computed tomography images. ConclusionsThis study revealed that t-PA injection using EBUS-TBNI is an effective and safe way to dissolve clots.

Automated Intracranial Clot Detection: A Promising Tool for Vascular Occlusion Detection in Non-Enhanced CT.

(1) Background: to test the diagnostic performance of a fully convolutional neural network-based software prototype for clot detection in intracranial arteries using non-enhanced computed tomography (NECT) imaging data. (2) Methods: we retrospectively identified 85 patients with stroke imaging and one intracranial vessel occlusion. An automated clot detection prototype computed clot location, clot length, and clot volume in NECT scans. Clot detection rates were compared to the visual assessment of the hyperdense artery sign by two neuroradiologists. CT angiography (CTA) was used as the ground truth. Additionally, NIHSS, ASPECTS, type of therapy, and TOAST were registered to assess the relationship between clinical parameters, image results, and chosen therapy. (3) Results: the overall detection rate of the software was 66%, while the human readers had lower rates of 46% and 24%, respectively. Clot detection rates of the automated software were best in the proximal middle cerebral artery (MCA) and the intracranial carotid artery (ICA) with 88-92% followed by the more distal MCA and basilar artery with 67-69%. There was a high correlation between greater clot length and interventional thrombectomy and between smaller clot length and rather conservative treatment. (4) Conclusions: the automated clot detection prototype has the potential to detect intracranial arterial thromboembolism in NECT images, particularly in the ICA and MCA. Thus, it could support radiologists in emergency settings to speed up the diagnosis of acute ischemic stroke, especially in settings where CTA is not available.

Computational modeling of blood clot lysis considering the effect of vessel wall and pulsatile blood flow.

Stroke is one of the major causes of global death, which can occur due to blockage in a blood vessel by a clot. The immediate dissolving of the clot is essential to restore the blood flow and prevent tissue necrosis. Clot dissolution can be achieved via thrombolytic therapy using plasminogen activators. In this study, a clot dissolution model is developed for a three-dimensional patient-specific carotid artery that investigates the effect of different vessel wall models on clot dissolution. The lysis pattern of the clot and hemodynamics of blood flow are evaluated using three different models of the vessel wall, namely, rigid, linear elastic, and Mooney-Rivlin hyperelastic. The effect of flow condition is considered by solving the Navier-Stokes equationsfor the free flow domain and the Brinkman equationfor the clot domain with the same pressure and velocity fields. This will result in continuous pressure and velocity over the interfaces of the free flow and clot domains. The blood inflow is assumed to be pulsatile. In addition, the species transport driven by diffusion and convection is considered to be different in the porous medium and plasma. The obtained results show that in all models, the starting time of clot volume decrease is almost the same and the clot starts dissolving from the inner curvature of the artery. However, in the hyperelastic model, dissolving the clot takes longer compared to the other two models. By monitoring the vessel wall deformation, the exact time of vessel recanalization is determined.

Primary Brainstem Hemorrhage—An Institutional Series From a Stroke Register and Evaluation of Outcome Determinants

Objective Primary brainstem hemorrhage (PBH) carries poor prognosis and the need for aggressive management is a matter of debate especially in developing countries with limited resources. The aim of this study was to analyze the prognostic factors in mortality prediction following PBH in a series of 59 consecutive patients. Methods A single institutional, retrospective, cohort study with a study period of 6 years (2016-2021). All patients with computerized tomography-proven intracerebral hematoma in the midbrain, pons, or medulla, alone or in combination were included in the study. Outcome was analyzed using a modified Rankin score (mRS) and was categorized into good (mRS 0, 1, 2, and 3), poor (mRS 4 and 5), and death. Statistical analysis was done using univariate regression analysis followed by multivariate regression analysis and a P value &lt; .05 was considered significant. Results A total of 59 patients diagnosed with primary brainstem hematoma were included in the study. Of the 59 patients, 40 (67.79%) were males and 19 (32.2%) were females, with a mean age of 55.51 ± 13.46 (range of 29-93 years). The median admission GCS score on admission was 6. No definite history of hypertension could be elicited in 18 patients (30.50%). The most common site for a brain stem hematoma was the pons 47 (79.9%) followed by pons-midbrain combination (06 10.2%). The average clot volume was 7.78 ± 6.5 mL. Fourth ventricular extension was seen in 18 patients (28.8%%) of whom 15 (27.2%) developed hydrocephalus. All patients were managed conservatively. At 3 months, 34 patients (57.62%) succumbed to the illness while 25 survived (42.37%) of whom only 12 had a good outcome (mRS 0-3). In addition to GCS score &lt; 8, ( P &lt; .001) large clot volume (&gt;10 mL) ( P &lt; .001), high systolic blood pressure on admission, and intraventricular extension, a high admission neutrophil-to-lymphocyte ratio (NLR) ( P &lt; .03) was found to have significant correlation with mortality. Conclusion Brainstem hemorrhage has a high mortality and few patients have good clinical outcome. Admission GCS, clot volume, hypertensive in etiology, and a high NLR are poor prognostic factors. Low GCS on admission is the most important and independent predictor of mortality and poor outcome.

Neural network for autonomous segmentation and volumetric assessment of clot and edema in acute and subacute intracerebral hemorrhages

IntroductionMinimally-invasive surgical techniques for intracerebral hemorrhage (ICH) evacuation use imaging to guide the suction, lysing and/or drainage from the hemorrhage site via various designs. A previous international surgical study has shown that reduction of hematoma volume below 15 ml is indicative of improved long term patient outcomes. The study noted a need for tools to periodically visualize remaining clot during intervention to increase the likelihood of evacuating sufficient clot volumes without endangering rebleeds. Robust segmentation of MRI could guide surgeons and radiologists regarding remaining regions and approaches for prudent evacuation. We thus propose a Convolutional Neural Network (CNN) to identify and autonomously segment clot and peripheral edema in MR images of the brain and generate an estimate of the remaining clot volume. Materials and methodsWe used a retrospective, locally-acquired dataset of ICH patient scans taken on 3 T MRI scanners. Three sets of ground truth manual segmentations were independently generated by two imaging scientists and one radiology fellow. Evaluation of clot age was determined based on relative contrast of hemorrhage components and reviewed by a neurosurgeon. Model accuracy was determined by pixel-wise Dice coefficient (DC) calculations between each ground truth manual segmentation and the machine-derived autonomous segmentations. ResultsThe model produced autonomous segmentations of clot core with an average DC of 0.75 ± 0.21 relative to manual segmentations of the same scans. For edema, it produced segmentations with an average DC of 0.68 ± 0.16 relative to manual. From these pixel-wise segmentations, clot volume can be calculated. Model-produced segmentations underestimated clot volumes by an average of 17% relative to ground-truth. ConclusionThe machine learning models were able to identify and segment volumes of ICH components swiftly and accurately.

Quamdiu? Time to proficiency in endoscope-assisted minimally invasive clot evacuation

IntroductionSpontaneous intraparenchymal brain hemorrhages are a devastating disease associated with significant disability or death. Minimally invasive clot evacuation (MICE) techniques can reduce mortality. We reviewed our experience with learning endoscope-assisted MICE to determine whether adequate results could be obtained in less than 10 cases. MethodsWe performed a retrospective chart review of patients undergoing endoscope-assisted MICE at a single institution by a single surgeon from January 1, 2018 to January 1, 2023 using a neuro-endoscope, a commercial clot evacuation device, and frameless stereotaxis. Demographic data was collected along with surgical results and complications. Image analysis using software determined the degree of clot removal. Hospital length of stay and functional outcomes were assessed using the Glasgow Coma Scale score (GCS) and Glasgow Outcome Score (extended) (GOS-E). ResultsEleven patients were identified: average age 60.82 years old, 64 % male, all had hypertension. There was a clear improvement in IPH evacuation over the series. By case #7, greater than 80 % of clot volume was evacuated consistently. All patients remained neurologically stable or improved following surgery. In long-term follow-up, four patients (36.4 %) had good outcomes (GOS-E ≥ 6) and 2 patients had fair outcomes (GOS-E = 4) (18 %). There were no surgical mortalities, re-hemorrhages, or infections. ConclusionsWith an experience of less than 10 cases, it is possible to obtain results comparable to most published series of endoscope-assisted MICE. Benchmarks such as greater than 80 % volume removal, less than 15 mL residual, and 40 % good functional outcomes can be obtained.