Utilización de escalas no invasivas en la detección de varices esofágicas en pacientes con trombosis venosa portal / Use of non-invasive scales for detecting esophageal varices in paediatric patients with portal vein thrombosis

Introducción La trombosis portal (TVP) es la causa más frecuente de hipertensión portal en población pediátrica. El Consenso de Baveno VI considera la ligadura endoscópica de varices como segunda opción terapéutica tras el meso-Rex-bypass (shunt quirúrgico). Objetivo Analizar la rentabilidad diagnóstica de escalas no invasivas para predecir el riesgo de varices esofágicas en niños con TVP. Material y métodos Estudio descriptivo retrospectivo donde se incluyeron endoscopias digestivas altas (EDA) en pacientes<15 años con TVP no cirróticos. Se dividieron según la presencia de varices esofágicas y se estudiaron sexo, etiología, edad, hemorragia digestiva o tratamientos previos, resultados de EDA y las escalas (Regla Predicción Clínica-CPR, Regla Predicción Varices-VPR, King's Variceal Prediction Score-K-VaPS y ratio plaquetas/bazo-RPB). Las variables cualitativas se expresaron mediante frecuencia absoluta y porcentaje, y las cuantitativas mediante mediana y rango intercuartílico. Para las comparaciones se emplearon los test U de Mann-Whitney y Hanley-McNeil. Resultados Se realizaron 45 EDA. Un 80%(n=36) presentaron varices esofágicas: mediana de 3(2 – 3) y un 33,3%(n=12) precisó ligadura endoscópica de varices. Se demostraron diferencias estadísticamente significativas entre ambos grupos: CPR (142,39 [132,22 - 166,53] vs. 122,75 [115,24 – 133,15] p=0,003), VPR (9,91 [9,36 – 11,75] vs. 5,6 [3,34 – 8,39] p=0,001), K-VaPS (117,86 [99,66 - 126,58] vs. 99,64 [94,88 - 110,18] p=0,019), RPB (2384,62 [1902,22 - 3201,63] vs. 1252,5 [579,6 - 2144,42] p=0,05), con un área bajo la curva>75%, sin demostrarse diferencias entre escalas. Conclusiones En pacientes pediátricos con TVP no cirróticos se pueden emplear escalas no invasivas como herramienta para predecir la presencia de VE y plantear con ello la indicación de EDA. (AU)

Introduction Portal vein thrombosis (PVT) is the most frequent cause of portal hypertension in paediatric population. Baveno VI Consensus considers endoscopic variceal ligation as the second therapeutic option after meso-Rex bypass (surgical shunt). Aim Analyse the diagnostic profitability of non-invasive scales in order to predict the risk of oesophageal varices (OV) in children with PVT. Material and methods Descriptive retrospective study where every upper gastrointestinal endoscopy (UGE) carried on patients <15 years old with non-cirrhotic PVT were included. There were divided according to the presence of OV and sex, cause, age, previous gastrointestinal bleeding or treatments, results of UGE and scales (Clinical Prediction Rule – CPR), Varices Prediction Rule – VPR), King's Variceal Prediction Score – K-VaPS) and Platelet count/Spleen diameter Ratio – PSR). Qualitative variables were expressed as absolute frequency and percentage, and quantitative variables as median and interquartile range. U Mann–Whitney and Hanley–McNeil tests were used for comparisons. Results Forty-five UGE were analysed. 80% (n=36) presented OV: median of 3 (2–3) and 33.3% (n=12) required endoscopic variceal ligation. Statistical differences were demonstrated between both groups: CPR (142.39 [132.22-166.53] vs. 122.75 [115.24-133.15]; p=0.003), VPR (9.91 [9.36-11.75] vs. 5.6 [3.34-8.39]; p=0.001), K-VaPS (117.86 [99.66-126.58] vs. 99.64 [94.88-10.18]; p=0.019), PSR (2384.62 [1902.22-3201.63] vs. 1252.5 [579.6-2144.42]; p=0.05), with and area under the curve AUROC>75%, without statistical differences between scales. ConclusionsIn paediatric patients with non-cirrotic PVT non-invasive scales can be used as a tool to predict the presence of OV and raise the indication of UGE. (AU)

Acute ischaemic stroke and deep vein thrombosis following snakebite.

Snakebite envenomation remains a neglected tropical public health issue claiming thousands of lives every year. It is a common medical emergency and a threat to the impoverished populations of low-income and middle-income countries including India. A combination of ischaemic stroke and deep vein thrombosis is a devastating duo complication of snake bite, with no literature report to date. Here, the authors report an unusual case of a young woman developing ischaemic stroke and deep vein thrombosis following snakebite even after the use of antivenom. MRI brain showed right thalamic infarct with haemorrhagic transformation and, ultrasound Doppler revealed right lower limb deep vein thrombosis. The pathophysiology of deep vein thrombosis and ischaemic stroke is complex. It is believed that the activation of the coagulation cascade, complement system together with endothelial injury and immune activation leads to inflammation, thrombosis and occlusion of smaller and even larger vessels.

Portal vein thrombosis as extraintestinal complications of Crohn's disease: a case report and review of literature.

INTRODUCTION: Thrombotic events are more than twice as common in inflammatory bowel disease patients as in the general population. We report an interesting and rare case of portal vein thrombosis as a venous thromboembolic event in the context of extraintestinal manifestations of Crohn's disease. We also conducted a literature review on portal vein thrombosis associated with inflammatory bowel disease, with the following concepts: inflammatory bowel diseases, ulcerative colitis, Crohn's disease, portal vein, and thrombosis. CASE PRESENTATION: A 24-year-old Syrian female with active chronic Crohn's disease was diagnosed 11 years ago and classified as A1L3B1P according to the Montreal classification. She had no prior surgical history. Her previous medications included azathioprine and prednisolone. Her Crohn's disease activity index was 390 points. Gastroduodenoscopy revealed grade I esophageal varices, a complication of portal hypertension. Meanwhile, a colonoscopy revealed several deep ulcers in the sigmoid, rectum, and descending colon. An investigation of portal vein hypertension revealed portal vein thrombosis. We used corticosteroids to induce remission, followed by tapering; additionally she received ustekinumab to induce and maintain remission. She began on low-molecular-weight heparin for 1 week, warfarin for 3 months, and then apixaban, a novel oral anticoagulant, after excluding antiphospholipid syndrome. Primary prophylaxis for esophageal varices was not required. After 1 year, she achieved clinical, biochemical, and endoscopic remission. Despite 1 year of treatment, a computed tomography scan revealed no improvement in portal vein recanalization. CONCLUSION: Portal vein thrombosis is a rare and poorly defined complication of inflammatory bowel disease. It is usually exacerbated by inflammatory bowel disease. The symptoms are nonspecific and may mimic a flare-up of inflammatory bowel disease, making the diagnosis difficult. Portal vein Doppler ultrasound for hospital-admitted inflammatory bowel disease patients may contribute to the diagnosis and management of this complication.

Disasters that develop in the liver due to hydatid cyst: a case report.

Hilar cavernous transformation is the formation of venous structures rich in collateral around the portal vein. Portal vein thrombosis is a rare entity. Although there are many reasons for its etiology, few cases have been reported secondary to hydatid cysts in the liver. Here, we present a 24-year-old patient with complaints of abdominal pain and swelling. Her CT and MRI scans show cholelithiasis with portal vein thrombosis and hilar cavernous transformation due to giant hydatid cyst compression in the lateral liver sector.

La transformación cavernosa hiliar es la formación de estructuras venosas ricas en colaterales alrededor de la vena porta. La trombosis de la vena porta es una afección poco frecuente. Aunque existen muchas razones en su etiología, se han descrito pocos casos secundarios a quiste hidatídico en el hígado. Aquí se presenta el caso de una paciente de 24 años con quejas de dolor abdominal e hinchazón. La tomografía computarizada y la resonancia magnética mostraron colelitiasis con trombosis de la vena porta y transformación cavernosa hiliar por compresión del quiste hidatídico gigante en el sector lateral del hígado.

Should all critical care patients with a central venous catheter in situ be screened for central catheter related thrombosis?

There are many studies on central catheter related thrombosis (CCRT), however, there are significantly fewer studies focusing on the incidence and evolution of CCRT in the adult critical care population. This article reviews data collected from observational studies that have performed bedside duplex ultrasound for surveillance of CCRT and discuss if we should routinely screen for CCRT. The reported CCRT incidence is 17-38%, with most thrombus being detectable on ultrasound within seven days of line placement. Nearly all CCRT are designated as asymptomatic (no associated pulmonary embolism (PE) or deep vein thrombosis (DVT)) and no significant changes in mortality rates amongst patients that develop CCRT were reported. Based on the evidence reviewed, we do not recommend screening routinely for CCRT in the adult critical care population.

Re-188 lipiodol in hepatocellular carcinoma with portal vein thrombosis: a pilot study using novel chelating agent N-DEDC and its comparison with (A)HDD.

OBJECTIVE: Hepatocellular carcinoma (HCC) with portal vein thrombosis (PVT) have limited therapeutic options, Re-188 lipiodol transarterial therapy being one of them. We aimed to assess the safety and efficacy of Re-188 lipiodol exclusively in HCC with PVT as well as to compare two chelating agents for the synthesis of Re-188 lipiodol: novel bis-(diethyldithiocarbamato) nitrido (N-DEDC) with existing acetylated 4-hexadecyl 1-2,9,9-tetramethyl-4,7-diaza-1,10-decanethiol [(A)HDD]. METHODS: Patients with radiological diagnosis of HCC with PVT having Eastern Cooperative Oncology Group (ECOG) performance status ≤2 and Child Pugh score (PS) A or B were recruited. Patients received an empirical dose of transarterial Re-188 lipiodol, labelled with (A)HDD or N-DEDC. Radiological response on MRI (modified response evaluation criteria in solid tumors), biochemical response with serum alpha fetoprotein and clinical response with ECOG PS was assessed at three months and survival was estimated at the end of the study. RESULTS: Fifteen therapies were performed in 14 patients with a median age of 62 years (range: 41-70 years). Eight therapies were with Re-188 (A)HDD lipiodol and seven with Re-188 N-DEDC lipiodol. Overall mean injected dose was 2.6 ±â€…0.37 GBq. Radiological objective response rate was 31% and disease control rate was 85%. Mean overall survival was 14.21 months and mean progression free survival was 10.23 months. Percentage survival assessed at 3, 6 and 9 months was 93%, 64% and 57%, respectively. Safety parameters, response and survival outcome were comparable for (A)HDD and N-DEDC groups. CONCLUSION: Transarterial Re-188 lipiodol in HCC with PVT is safe and effective in disease control as well as improving survival outcome. Additionally, cost-effective and high-yielding novel agent N-DEDC appears to be a comparable alternative to (A)HDD for the same.

The Value of Coagulation-Related Indicators Combined with Vascular Ultrasound Parameters in the Risk Assessment of Deep Vein Thrombosis after Secondary Traumatic Fracture Surgery.

OBJECTIVE: The incidence of deep vein thrombosis (DVT) after traumatic fracture is high, and DVT causes serious adverse effects on the postoperative recovery of patients. The purpose of this study was to explore the effect of coagulation-related indicators combined with vascular ultrasound measurements for the risk assessment of DVT after secondary traumatic fracture, and to provide a new method for predicting the occurrence of DVT. METHODS: The clinical data of patients with secondary traumatic fracture surgery in our hospital from January 2019 to January 2022 were retrospectively analyzed. The patients were divided into a non-DVT group and a DVT group according to whether DVT was indicated in the medical record system. The coagulation-related indices and vascular ultrasound measurements of the two groups were compared, and the risk factors for postoperative DVT were analyzed by bivariate correlation and multivariate logistic regression. RESULTS: According to the medical record system, 55 patients (47.41%) had DVT, and 61 patients (52.59%) did not have DVT. There was no significant difference in prothrombin time (PT) or activated partial thromboplastin time (APTT) between the two groups (p > 0.05). The thrombin time (TT) in the DVT group was lower than that in the non-DVT group. The levels of fibrinogen (FIB) and D-dimer (D-D) in the DVT group were higher than those in the non-DVT group (t = 2.766, 3.242, 2.649, p = 0.007, 0.002, 0.009). Spearman correlation analysis showed that peak systolic velocity (Vs), end-diastolic velocity (Vd), pulsatility index (PI), resistance index (RI), FIB, and D-D were positively correlated with the risk of DVT after secondary traumatic fracture surgery (r = 0.264, 0.656, 0.293, 0.276, 0.287, 0.251, p < 0.05). TT was negatively correlated with DVT risk after secondary traumatic fracture surgery (r = -0.249, p < 0.05). The measurements of peak systolic velocity (Vs), end diastolic velocity (Vd), pulsatility index (PI) and resistance index (RI) in the DVT group were higher than those in the non-DVT group (t = 2.663, 2.998, 3.135, 2.953, p = 0.009, 0.003, 0.002, 0.004). FIB, D-D, Vs, Vd, PI, and RI were independent risk factors for DVT after secondary traumatic fracture surgery (Odds Ratio (OR) = 1.483, 2.026, 2.208, 1.893, 1.820, 1.644, p < 0.05). TT index was an independent protective factor for DVT after secondary traumatic fracture surgery (OR = 0.868, p < 0.05). The sensitivity and specificity for prediction of DVT based on combined coagulation-related indicators and vascular ultrasound imaging measurements were higher than those of individual measurements (p < 0.05). CONCLUSIONS: Coagulation-related indicators and vascular ultrasound parameters can effectively predict the formation of DVT. Through the analysis of factors related to DVT formation, screening of high-risk patients for effective intervention may help to reduce the risk of DVT. Further verification in additional, large-scale clinical trials is advocated.

Ultrasound Performed by Emergency Physicians for Deep Vein Thrombosis: A Systematic Review.

Introduction: Point-of-care ultrasound (POCUS) performed by emergency physicians (EP) has emerged as an effective alternative to radiology department ultrasounds for the diagnosis of lower extremity deep vein thrombosis (DVT). Systematic reviews suggested good sensitivity and specificity overall for EP-performed POCUS for DVT diagnosis, yet high levels of heterogeneity were reported. Methods: In this systematic review and meta-analysis, we aimed to provide the most up-to-date estimates of the accuracy of EP-performed POCUS for diagnosis of DVT and to explore potential correlations with test performance. We performed systematic searches in MEDLINE and Embase for original, primary data articles from January 2012-June 2021 comparing the efficacy of POCUS performed by EPs to the local standard. Quality Assessment of Diagnostic Accuracy Studies-2 for individual articles are reported. We obtained summary measures of sensitivity, specificity, and their corresponding 95% confidence intervals (CI) using bivariate mixed-effects regression models. We performed meta-regression, subgroup, and sensitivity analyses as planned in the protocol CRD42021268799 submitted to PROSPERO. Results: Fifteen publications fit the inclusion criteria, totaling 2,511 examinations. Pooled sensitivity and specificity were 90% (95% CI 82%-95%) and 95% (CI 91%-97%), respectively. Subgroup analyses by EP experience found significantly better accuracy for exams performed by EP specialists (93%, CI 88%-97%) vs trainees (77%, CI 60%-94%). Specificity for EP specialists (97%, CI 94%-99%) was higher than for trainees (87%, CI 76%-99%, P = 0.01). Three-point compression ultrasound (CUS) was more sensitive than two-point CUS but was only statistically significant when limited to EP specialists (92% vs 88%, P = 0.07, and 95% vs 88%, P = 0.02, respectively). Conclusion: Point-of-care ultrasound performed by emergency physicians is sensitive and specific for the diagnosis of suspected DVT when performed by trained attending EPs. Three-point compression ultrasound examination may be more sensitive than two-point CUS.

Incidence of deep venous thrombosis in patients with hemophilia undergoing bilateral simultaneous total knee arthroplasty: a retrospective cohort study.

BACKGROUND: Hemophilic arthropathy usually affects the knees bilaterally. In order to reduce costs and improve rehabilitation, bilateral simultaneous total knee arthroplasty (TKA) can be performed. However, pharmacological prophylaxis for deep venous thrombosis (DVT) remains controversial in patients with severe hemophilia. The purpose of this study was to establish the incidence of DVT in severe hemophilia A patients undergoing bilateral simultaneous TKA without pharmacological thromboprophylaxis. METHODS: Consecutive patients with severe hemophilia A undergoing bilateral simultaneous TKA at a single center between January 2015 and December 2020 were retrospectively reviewed. All patients received a modified coagulation factor substitution regimen. Tranexamic acid (TXA) was used for hemostasis in all patients during surgery. All patients followed a standardized postoperative protocol with routine mechanical thromboprophylaxis, and none received anticoagulation. D-dimer was measured preoperatively, on the day of the operation and on postoperative days 1, 7 and 14. Ultrasound (US) of the lower extremities was performed before (within 3 days of hospitalization) and after surgery (days 3 and 14) to detect asymptomatic DVT. Patients were followed up until 2 years after surgery for the development of symptomatic DVT or pulmonary embolism (PE). RESULTS: 38 male patients with severe hemophilia A underwent 76 simultaneous TKAs. Mean (± standard deviation) age at the time of operation was 41.7 (± 17.1) years. Overall, 47.3% of patients had D-dimer concentrations above the threshold 10 µg/mL on day 7 and 39.5% on day 14. However, none of the patients had DVT detected on postoperative US, nor developed symptomatic DVT or PE during the 2-year follow-up. CONCLUSIONS: The risk of DVT in patients with severe hemophilia A after bilateral simultaneous TKA is relatively low, and routine pharmacological thromboprophylaxis may not be needed.

A Case of Gallbladder Cancer with Trousseau Syndrome Successfully Treated Using Radical Resection.

Trousseau syndrome is characterized by cancer-associated systemic thrombosis. We describe the first case of a successfully treated gallbladder adenocarcinoma accompanied by Trousseau syndrome. A 66-year-old woman presented with right hemiplegia. Magnetic resonance imaging identified multiple cerebral infarctions. Her serum carbohydrate antigen 19-9 and D-dimer levels were markedly elevated, and a gallbladder tumor was detected via abdominal computed tomography. Venous ultrasonography of the lower limbs revealed a deep venous thrombus in the right peroneal vein. These findings suggested that the brain infarctions were likely caused by Trousseau syndrome associated with her gallbladder cancer. Radical resection of the gallbladder tumor was performed. The resected gallbladder was filled with mucus and was pathologically diagnosed as an adenocarcinoma. Her postoperative course was uneventful, and she received a one-year course of adjuvant therapy with oral S-1. No cancer recurrence or thrombosis was noted 26 months postoperatively. Despite concurrent Trousseau syndrome, a radical cure of the primary tumor and thrombosis could be achieved with the appropriate treatment.

Ovarian vein thrombus in a pediatric patient: A case study.

Acute abdominal pain is a very common chief complaint in the pediatric population, accounting for 5-10% of emergency department (ED) visits. Etiology differentiation is determined by complete history and physical examination, basic laboratory studies, and a variety of imaging study options. In this case report, we present an 8-year-old female with an unusual etiology of acute lower abdominal pain. She presented with tachycardia, hypertension, and bilateral lower quadrant abdominal tenderness without peritonitis. Laboratory studies were unremarkable and appendix ultrasound was indeterminate. CT with contrast revealed right ovarian vein thrombosis. Hematology evaluation did not reveal hypercoagulability. She was discharged on rivaroxaban, which was discontinued after a 3 month course and negative follow-up MRI. Ovarian vein thrombosis (OVT) most commonly develops in the peripartum time frame, with an estimated 20%-40% of cases not related to pregnancies. However, patients with nonpregnancy related OVT were determined to be significantly older than patients with pregnancy related OVT. This case report demonstrates the youngest documented case of OVT. This patient was not in the peripartum period and did not have any identifiable risk factors. Given this unprovoked OVT in a pediatric patient, in patients presenting with abdominal pain with unspecified etiology, advanced imaging studies may be helpful in establishing a diagnosis.

Venous Thrombosis in Acute Pancreatitis: What to and Not to Do?

Acute pancreatitis is an acute inflammatory condition of the pancreas that has not only local but systemic effects as well. Venous thrombosis is one such complication which can give rise to thrombosis of the peripheral vasculature in the form of deep vein thrombosis, pulmonary embolism, and splanchnic vein thrombosis. The prevalence of these complications increases with the severity of the disease and adds to the adverse outcomes profile. With better imaging and awareness, more cases are being detected, although many at times it can be an incidental finding. However, it remains understudied and strangely, most of the guidelines on the management of acute pancreatitis are silent on this aspect. This review offers an overview of the incidence, pathophysiology, symptomatology, diagnostic work-up, and management of venous thrombosis that develops in AP.

Management of isolated distal deep vein thrombosis.

Isolated distal deep vein thrombosis (DVT) represents up to 50% of all lower limb DVT in ultrasound series and is a frequent medical condition, which management is not well established. Data arising from registries and non-randomized studies suggest that most distal DVTs do not extend to the proximal veins and have an uneventful follow-up when left untreated. This data had some impact on international recommendations like the American College of Chest Physicians (ACCP), whose last version stated that ultrasound surveillance might be an option for selected low-risk patients. However, robust data arising from randomized studies are scarce. Indeed, only seven randomized trials assessing the need for anticoagulation for calf DVT have been published. Many of these trials had an open-label design and were affected by methodological limitations. When considering randomized placebo-controlled trials, one included low-risk patients and was hampered by a limited statistical power (CACTUS study). Nevertheless, data from this trial tend to confirm that the use of therapeutic anticoagulation in low-risk patients with symptomatic calf DVT is not superior to placebo in reducing VTE but is associated with a higher risk of bleeding. A second randomized placebo-controlled trial did not assess the necessity of anticoagulant treatment but rather the long-term risk of recurrence and compared 6 weeks versus 12 weeks of treatment with rivaroxaban (RIDTS study). Finally, the last available randomized trial compared a 3-month versus a 12-month edoxaban treatment in patients with cancer and mainly asymptomatic distal DVT, detected by systematic compression ultrasonography. Overall, available data suggest that the use of therapeutic anticoagulation in low-risk patients with symptomatic calf DVT is not superior to placebo in reducing VTE. High risk patients (previous VTE, active cancer, inpatients) might benefit from a course of anticoagulant treatment. However, the optimal anticoagulant intensity and duration are uncertain and further studies are needed.

A child with intravascular fasciitis mimicking deep vein thrombosis: a case report.

BACKGROUND: Intravascular fasciitis (IF) is a benign, reactive, myofibroblastic proliferation that originates from the superficial or deep fascia of small / medium-sized arteries and veins. CASE REPORT: An 8-year-old male patient was admitted to a health center with the complaint of swelling in the inguinal region. Lower extremity venous Doppler ultrasonography showed deep vein thrombosis (DVT) of the femoral vein and anticoagulation with low-molecular weight heparin (LMWH) was initiated. The patient was referred to our center for follow-up. The D-dimer level was detected within normal limits. Doppler ultrasonography was repeated and showed an intraluminal expanding mass lesion with increasing vascularity, without distinct borders and LMWH was discontinued. This lesion at the sapheno-femoral junction was excised surgically and the histopathological examination revealed intravascular fasciitis. CONCLUSION: Clinicians should be aware that the clinical findings of IF may mimic sarcoma and thrombosis.

Lung cancer with bilateral internal jugular vein thrombosis.

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Extensive Hepatic Infarction due to Polycythemia Vera.

Polycythemia vera (PV) is one of the three BCR-ABL1-negative myeloproliferative neoplasms characterized by activating mutations in JAK2, which clinically presents as erythrocytosis and has an increased risk of both thromboembolic events and progression to myelofibrosis and acute myeloid leukemia. Splanchnic vein thrombosis is a rare manifestation of venous thromboembolism involving one or more abdominal vessels and is strongly associated with PV. We herein report a case in which hepatic infarction due to PV was saved by conservative treatment.

Does Thrombosis Play a Causal Role in Lacunar Stroke and Cerebral Small Vessel Disease?

BACKGROUND: The importance of thromboembolism in the pathogenesis of lacunar stroke (LS), resulting from cerebral small vessel disease (cSVD), is debated, and although antiplatelets are widely used in secondary prevention after LS, there is limited trial evidence from well-subtyped patients to support this approach. We sought to evaluate whether altered anticoagulation plays a causal role in LS and cSVD using 2-sample Mendelian randomization. METHODS: From a recent genome-wide association study (n=81 190), we used 119 genetic variants associated with venous thrombosis at genome-wide significance (P<5*10-8) and with a linkage disequilibrium r2<0.001 as instrumental variables. We also used genetic associations with stroke from the GIGASTROKE consortium (62 100 ischemic stroke cases: 10 804 cardioembolic stroke, 6399 large-artery stroke, and 6811 LS). In view of the lower specificity for LS with the CT-based phenotyping mainly used in GIGASTROKE, we also used data from patients with magnetic resonance imaging-confirmed LS (n=3199). We also investigated associations with more chronic magnetic resonance imaging features of cSVD, namely, white matter hyperintensities (n=37 355) and diffusion tensor imaging metrics (n=36 533). RESULTS: Mendelian randomization analyses showed that genetic predisposition to venous thrombosis was associated with an increased odds of any ischemic stroke (odds ratio [OR], 1.19 [95% CI, 1.13-1.26]), cardioembolic stroke (OR, 1.32 [95% CI, 1.21-1.45]), and large-artery stroke (OR, 1.41 [95% CI, 1.26-1.57]) but not with LS (OR, 1.07 [95% CI, 0.99-1.17]) in GIGASTROKE. Similar results were found for magnetic resonance imaging-confirmed LS (OR, 0.94 [95% CI, 0.81-1.09]). Genetically predicted risk of venous thrombosis was not associated with imaging markers of cSVD. CONCLUSIONS: These findings suggest that altered thrombosis plays a role in the risk of cardioembolic and large-artery stroke but is not a causal risk factor for LS or imaging markers of cSVD. This raises the possibility that antithrombotic medication may be less effective in cSVD and underscores the necessity for further trials in well-subtyped cohorts with LS to evaluate the efficacy of different antithrombotic regimens in LS.