BackgroundDirect oral anticoagulants (DOACs) are recommended as first-line treatment for acute venous thromboembolism (VTE). The recommended regimen of apixaban and rivaroxaban requires a higher-intensity lead-in phase. However, clinicians may use reduced lead-in strategies due to concerns regarding bleeding risk, planned procedures, or prior parenteral anticoagulation. Recent evidence indicates that reduced lead-in dosing may provide comparable clinical outcomes compared to the recommended full lead-in dosing.MethodsIn this study, recent observational studies comparing reduced versus full lead-in apixaban or rivaroxaban therapy in acute VTE were systematically synthesized. Eligible studies included those involving adults treated with apixaban or rivaroxaban in which the lead-in duration was compared. Outcomes assessed included recurrent VTE, bleeding, and mortality.ResultsNine studies were included in this systematic review; reduced lead-in therapy did not increase VTE recurrence compared with full lead-in regimens. In addition, in these studies, no significant difference was found in major bleeding, clinically relevant non-major bleeding, and mortality across all lead-in strategies.ConclusionEvidence demonstrates that reduced lead-in therapy may be both safe and effective in selected patients, particularly those previously treated with therapeutic parenteral anticoagulation. However, current evidence remains observational and heterogeneous. A target trial emulation is required to define optimal lead-in duration and guide patient-specific dosing strategies.

Regenerative medicine, characterized by breakthroughs in stem cell technology, cell-free therapies, and tissue engineering, holds immense promise for treating various diseases. However, along with the encouraging advancements in translational and clinical research, emerging evidence has demonstrated a potential risk of developing instant blood-mediated inflammatory reactions (IBMIRs) and venous thromboembolism (VTE) with the intravascular delivery of cellular products that do not naturally come into contact with blood. Tissue factor (TF), an initiator of the extrinsic coagulation cascade, plays a pivotal role in these processes. In this comprehensive review, we summarize the biological properties and multifaceted functions of TF in both health and disease. By understanding its physiological and pathological roles, we discuss the implications of TF for IBMIR and VTE in patients receiving cell therapy and extracellular vesicle (EV) therapy. VTEs, including deep vein thrombosis and pulmonary embolism, might have life-threatening consequences. During IBMIR, the recipient's innate immune cells and humoral coagulation factors drive a hyperacute thromboinflammatory response that traps the infused products, leading to rapid intravascular clearance and compromised therapeutic outcomes. Additionally, we introduce transplantation protocols that demonstrate prevention and monitoring strategies for TF-induced negative effects. Given the increasing complexity of clinical studies and the diverse applications of cell-based therapies, mitigating TF-induced thrombosis is crucial for safer and more effective treatments.

Intravascular temperature management (IVTM) is widely used for temperature control after cardiac arrest, but its association with IVTM-related venous thromboembolism (VTE) remains clinically important. D-dimer is commonly used for VTE evaluation, although interpretation is challenging after cardiac arrest because coagulation and fibrinolytic abnormalities can elevate D-dimer values. We conducted a single-center retrospective cohort study of out-of-hospital cardiac arrest patients treated with IVTM between August 2021 and August 2024. D-dimer levels were measured daily for 7 days and reported in µg/mL D-dimer units. IVTM-related VTE diagnosed within 10 days after admission was identified from medical records. Delta D-dimer was defined as the increase from each baseline value on Days 1, 2, or 3 to the peak value within 7 days. Among 51 patients, 8 (15.7%) developed IVTM-related VTE; the median time to diagnosis was 5.5 days. Peak D-dimer was higher in patients with IVTM-related VTE than in those without IVTM-related VTE (56.0 vs. 17.4 µg/mL DDU). Delta D-dimer was associated with IVTM-related VTE in adjusted logistic regression models, with adjusted odds ratios ranging from 1.04 to 1.10 per 1 µg/mL increase. In post-cardiac arrest patients undergoing IVTM, increases in D-dimer from early-phase values to peak were associated with IVTM-related VTE. Serial D-dimer assessment may help identify patients who warrant targeted imaging when IVTM-related VTE is clinically suspected.

In light of recent clinical trials, we are witnessing a paradigm shift towards lung parenchyma-preserving, sublobar resection for early-stage lung cancers. When performing sublobar resection via thoracoscopy, sometimes locating the lesion can be challenging. Thoracoscopy does not provide the same exposure and tactile feedback as open thoracotomy; as a result, detecting subsolid, small, and deep lesions can be difficult for the thoracic surgeon. This problem can be obviated by preprocedural marking of lesions. Various CT-guided transthoracic and bronchoscopic techniques have been reported. Transthoracic techniques include injecting dye into the lesions and placing fiducials and hook wires. Although these procedures are widely performed, complications, such as pneumothorax, air embolism, dye dissipation and extravasation, and hook-wire dislodgement have been reported. Conventional bronchoscopy can be used in conjunction with real-time 3-dimensional imaging for transbronchial marking of pulmonary lesions. However, given the limitations of conventional bronchoscopy, navigating to peripheral lesions can be tough. Robotic bronchoscopy, with or without real-time 3-dimensional imaging, is a safe and accurate modality for marking pulmonary lesions. Robotic bronchoscopy can be used to perform dye injection into the lesion, potentially in the same setting as the resection. Robotic bronchoscopy can also be used to bronchoscopically deploy dye-soaked coils. Robotic bronchoscopy may not be widely available and may have a learning curve. Ultimately, the choice of lung marking modality depends on available resources, institutional expertise, and the specific advantages and disadvantages of each modality.

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare but serious complication of acute pulmonary embolism. It may be clinically silent and often presents with non-specific symptoms, making diagnosis challenging. We present the case of a man in his 40s who presented with shortness of breath and acute hypoxic respiratory failure. His hypoxia persisted despite pneumonia and superimposed human metapneumovirus infection treatment.Despite two negative CT pulmonary angiograms, clinical suspicion for pulmonary vascular disease remained high given the otherwise unrevealing diagnostic workup, persistent tachycardia, right ventricular dysfunction on echocardiography and persistent mosaic attenuation on CT of the chest. A ventilation-perfusion scan ultimately showed CTEPH, later confirmed by right heart catheterisation and pulmonary angiography.This case highlights the complex presentation and diagnostic challenges of CTEPH. It emphasises that CTEPH should remain on the differential in patients with persistent hypoxia and signs of pulmonary hypertension, even when CT imaging does not demonstrate pulmonary embolism.