Superficial vein thrombosis of the upper extremities: A retrospective analysis of clot progression and role of thrombophilia testing

Abstract Introduction: There are well-established guidelines for the treatment of lower extremity (LE) deep venous thrombosis (DVT), but guidelines for upper extremity (UE) superficial venous thrombosis (SVT) are less specific. The current understanding is that superficial clots are self-limiting without increased morbidity and generally do not require thrombophilia testing or anticoagulation. This study aims to shed light on the risk of DVT or pulmonary embolism (PE) after a diagnosis of UE SVT, and the likelihood of patients getting tested for thrombophilia, with the hope that UE SVT risk can be stratified and guidelines for management can ultimately be developed. Methods: This is a retrospective analysis of 988 patients between 1/1/2024-1/31/2025. Slicer Dicer was used to capture patients on the electronic medical record, Epic, at University of California, San Diego across all affiliated locations. The patient base was “All patients” with a diagnosis of “Superficial venous thrombosis of upper extremity” (ID 24113987). Patients above 18 years old who had imaging evidence of cephalic and/or basilic vein thrombosis were included. Patients who had a prior or concurrent DVT and/or PE were excluded. Hypercoagulable testing is considered completed if there were lab results of more than one of the following: Beta 2 glycoprotein IgM or IgG, Cardiolipin IgM or IgG, testing for lupus anticoagulant, antithrombin III, Protein C, Protein S, Factor V Leiden, or prothrombin gene mutation. Results: Of the 988 patients, 431 were excluded. Mean age of the 557 patients was 58.31. There were 346 males and 211 females. 326 patients were White, 47 patients were Black or African American, 40 patients were Asian, and 163 patients were of other race or mixed race. Some patients identified with more than one race. 170 patients identified as Hispanic/Latino. Mean BMI was 26.88. 225 patients had right-sided SVT, 256 had left-sided SVT, and 76 had bilateral SVT. 406 SVT's were in the cephalic veins, and 234 SVT's were in the basilic veins. Some patients had SVT's in both veins. SVT was diagnosed in 444 patients during inpatient hospitalization, 56 in the emergency department (ED), and 89 in outpatient clinics. A subset of patients had recurrent episodes diagnosed in more than one clinical setting. 69 patients had hypercoagulable testing performed at some point, and 15 of those had hypercoagulable testing done specifically for the UE SVT. 11/15 of these patients were diagnosed with UE SVT in the ED or outpatient setting. Factor V Leiden was the most common positive finding, accounting for 5 of the patients, with 3 heterozygous patients and 2 homozygous patients. 2 patients are heterozygous for prothrombin gene mutation, 2 patients had decreased Protein S, 1 patient had a weak lupus anticoagulant, and 1 patient had elevated beta 2 glycoprotein IgM. Of the 557 patients who had isolated UE SVT, 10 patients had progression to PE (1.80%), and 27 patients had progression to ipsilateral UE DVT (4.85%). Discussion: The incidence of ipsilateral DVT after UE SVT was low, while the risk of PE was even lower. Most SVT's were diagnosed during hospitalizations, implying that these thromboses were provoked by multiple factors such as intravenous lines, prolonged immobility, procedures, infections, or malignancies. Thrombophilia testing was rarely performed, yet most patients who were tested had abnormal results, suggesting a potential association with UE SVT's, and an increased risk of serious thrombosis in the future. Limitations of this retrospective study include incomplete documentation and the inability to fully assess provoking factors. Crucial information, such as the precise location within the vein, degree of occlusion, clot length, and proximity to deep vein junctions, was often missing. Additionally, widespread use of prophylactic anticoagulation in hospitalized patients underestimates the true risk of thrombosis. Conclusion: In this retrospective study, the risk of propagation of UE SVT to a DVT or PE is low but clinically relevant, particularly in the inpatient setting when multiple potential provoking factors are present. The frequent detection of thrombophilia in tested individuals suggests an association; however, further investigation is needed to assess the benefit of anticoagulation, as well as for management guidelines and risk stratification for upper extremity superficial vein thrombosis.