Abstract. Background: The invasive management of varicose veins has a known risk of post-operative deep venous thrombosis and subsequent pulmonary embolism. The aim of this study was to evaluate absolute and relative risk of venous thromboembolism (VTE) following commonly used varicose vein procedures. Patients and methods: A retrospective analysis of secondary data using Hospital Episode Statistics database was performed for all varicose vein procedures performed between 2003 and 2013 and all readmissions for VTE in the same patients within 30 days, 90 days, and one year. Comparison of the incidence of VTEs between procedures was performed using a Pearson’s Chi-squared test. Results: In total, 261,169 varicose vein procedures were performed during the period studied. There were 686 VTEs recorded at 30 days (0.26 % incidence), 884 at 90 days (0.34 % incidence), and 1,246 at one year (0.48 % incidence). The VTE incidence for different procedures was between 0.15–0.35 % at 30 days, 0.26–0.50 % at 90 days, and 0.46–0.58 % at one year. At 30 days there was a significantly lower incidence of VTEs for foam sclerotherapy compared to other procedures (p = 0.01). There was no difference in VTE incidence between procedures at 90 days (p = 0.13) or one year (p = 0.16). Conclusions: Patients undergoing varicose vein procedures have a small but appreciable increased risk of VTE compared to the general population, with the effect persisting at one year. Foam sclerotherapy had a lower incidence of VTE compared to other procedures at 30 days, but this effect did not persist at 90 days or at one year. There was no other significant difference in the incidence of VTE between open, endovenous, and foam sclerotherapy treatments.
Chi-Squared test for constraining free parameters of modified Gravity on Brown Dwarfs
