A Pilot Trial Comparing Full Dose Rivaroxaban to Prophylactic Dose Rivaroxaban in Patients With Superficial Vein Thrombosis in the Leg

The goal of this clinical trial, called a pilot study or a feasibility study, is to test the study plan and to find out whether enough participants will join a larger study and accept the study procedures. This type of study includes a small number of participants so it is not expected to prove how safe the treatment is or how well the treatment works. The main question it hopes to answer is: 1.What is the average number of patients that are recruited per month during the 12 month study period? To test the study plan, adults being treated for a superficial vein thrombosis (SVT), which is a blood clot in the superficial veins of the leg, will be given a type of blood thinner called rivaroxaban. Half of the participants in this study will be given the standard (low-dose) rivaroxaban for 45 days, then 45 days of placebo (a substance that looks like the study medication but does not have any active or medicinal ingredients). The other half of participants will be given full-dose rivaroxaban for a total of 90 days. The placebo in this study is not intended to have any effect on the participants blood clot. A placebo is used to make the results of the study more reliable.