Superficial Vein Thrombosis

Superficial vein thrombosis (SVT) occurs when blood in a vein directly under the skin clots. SVT causes vein tenderness, pain, and skin discolouration. Over time, the vein hardens into a firm, nontender, easily palpable lump. SVT commonly occurs in the veins of the leg. Each year, 1 per 1000 people over the age of 18 have a superficial vein thrombosis (SVT). SVT is painful but usually gets better within a month. Four in 100 people with SVT develop progressively worse blood clotting involving the deep veins or lungs. If a deep vein clot in the leg occurs it can cause permanent disability with post-thrombotic syndrome (long-term leg pain and swelling) and reduced quality of life. If a pulmonary embolism occurs it may causes chest pain, breathlessness, pulmonary hypertension, psychological distress, and potentially death. Risk factors for SVT include varicose veins, pregnancy, cancer, the use of intravenous catheters, a history of venous thromboembolism, age, and thrombophilia. Guidelines tell doctors to use ultrasound scanning to decide whether SVT needs treatment with a blood thinner or not. Blood thinners prevent the clot from worsening. Many people who have SVT go to the emergency department. Scanning is limited to the daytime so often people have multiple trips to the emergency department for their scan and they spend many hours waiting for a doctor to see them. Our research group developed simple ways to limit the need for scans for other types of blood clots, like blood clots in the lungs or in the deep veins. We use a simple blood test called D-dimer. We believe we may be able to use D-dimer to help limit the need for SVT scanning. This is an exploratory study to document what happens to patients tested for SVT in the emergency department, and to see if the D-dimer blood test might be useful in reducing scans. We will review the emergency department charts for patients who came to the emergency department with SVT. Our results will tell us whether further studies would be helpful.

Superficial venous thrombosis (SVT) is very common in clinical practice. What's more, around 15- 20% of SVTs occur in the context of cancer. Today, cancer patients are excluded from therapeutic trials for DVT. There is therefore no high-level evidence-based treatment recommendation for these patients. Recent data suggest that the course of cancer-associated DVT is similar to that of cancer-associated deep vein thrombosis (DVT). However, there are currently few prospective data on the evolution of cancer-associated DVT in relation to the treatment used. Due to the absence of clear recommendations of treatment in case of SVT associated with cancer the investigators will perform a prospective observational study to evaluate the efficacy of different regiment of anticoagulant treatment ordered in clinical practice.

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.