Superficial Vein Thrombosis Testing in the Emergency Department (SVTest)

Evaluating Superficial Vein Thrombosis in the Emergency Department.

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.

Study Overview

• Status: Not yet recruiting
• Conditions: D-dimer; Superficial Vein Thrombosis
• Intervention / Treatment: Diagnostic test: D-dimer

• Study Type: Observational
• Enrollment (Estimated): 400

Contacts and Locations

• Study Contact: Name: Natasha S Clayton; Phone Number: 416-566-3590; Email: natasha.clayton@queensu.ca
• Study Contact Backup: Name: de Wit, MD

Study Locations

• Canada
  • Ontario
    • Kingston, Ontario, Canada, K7L 2V7
      • Emergency Medicine
      • Contact: Natasha S Clayton; Phone Number: 416-566-3590; Email: natasha.clayton@queensu.ca

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Emergency department patient who is tested for superficial vein thrombosis

Description

Inclusion Criteria:

• Aged ≥ 18
• Tested for superficial vein thrombosis in the emergency department or urgent care centre
• Patients tested for SVT at all sites, including arms, legs and torso

Exclusion Criteria:

• Patient opted out of research at the participating site
• Patient included in the study in the last 90 days

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Emergency department patients tested for superficial vein thrombosis	Diagnostic test: D-dimer; We will extract data on D-dimer blood test levels. This is an non-interventional study.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Superficial vein thrombosis, deep vein thrombosis and no thrombosis	We will classify superficial vein thrombosis as a) situated within 3 cm of the deep vein junction, b) ≥ 5 cm in length and > 3 cm from the deep vein junction, and c) SVT < 5 cm in length and > 3 cm from the deep vein junction. We will report diagnosis of deep vein thrombosis and the finding of no thrombosis.	During index testing

Secondary Outcome Measures

Outcome Measure	Time Frame
The secondary outcomes will the subsequent development of recurrent SVT, SVT propagation, deep vein thrombosis, pulmonary embolism, or death from pulmonary embolism among patients diagnosed with SVT at the index visit.	90 days

Collaborators and Investigators

• Sponsor: Dr. Kerstin de Wit
• Investigators: Principal Investigator: Kerstin de Wit, MD, Kingston Health Sciences Centre

Study record dates

Study Major Dates

• Study Start (Estimated): July 15, 2026
• Primary Completion (Estimated): July 1, 2028
• Study Completion (Estimated): July 1, 2029

Study Registration Dates

• First Submitted: June 22, 2026
• First Submitted That Met QC Criteria: June 22, 2026
• First Posted (Actual): June 26, 2026

Study Record Updates

• Last Update Posted (Actual): June 26, 2026
• Last Update Submitted That Met QC Criteria: June 22, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Emergency Medicine; D-dimer; diagnostic; Superficial vein thrombosis
• Additional Relevant MeSH Terms: Pathologic Processes; Pathological Conditions, Signs and Symptoms; Disease
• Other Study ID Numbers: CTO5894

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No