Natural History of Isolated Deep Vein Thrombosis of the Calf

Completed

• Conditions: Isolated Distal DVT; Proximal DVT; Pulmonary Embolism
• Interventions: Other: Ultrasound examination of leg veins

• Registration Number: NCT00816920
• Lead Sponsor: IRCCS Azienda Ospedaliero-Universitaria di Bologna

Brief Summary

Whether isolated distal DVT (IDDVT), DVT confined to the calf, should be looked for and diagnosed to allow them to be treated with anticoagulants remains one of the still unsolved issues in vascular medicine, especially because of the insufficient data on clinical risks of untreated distal DVT. Management studies have shown that it is safe to withhold anticoagulation in outpatients with suspected DVT if compression ultrasonography (CUS) limited to the proximal deep veins yields normal results on presentation and on repeated examination after 5 to 7 days. This strategy is based on the premise that IDDVT do not need to be diagnosed and treated, what is necessary when they extend involving the proximal veins. There is no general agreement, however, on the assumption that the non-extending IDDVT do not need to be diagnosed and treated, and many authors recommend to perform a single CUS examination extended to the distal deep veins. All the available studies have treated with anticoagulants the diagnosed IDDVT and no adequate information is available on the risk of IDDVT left untreated.

The present study, performed in outpatients with suspected leg DVT, aims at assessing the clinical consequences of IDDVT diagnosed (by a complete US investigation) but not treated because the results of this investigation remain blind to both the patient and the treating doctor, whereas the diagnostic-therapeutic procedure remains the usual one, based on CUS investigation limited to diagnose proximal DVT, to be repeated after 5-7 days (or earlier) to exclude an extension to proximal veins of an IDDVT potentially present.

Detailed Description

Outpatients symptomatic for suspected DVT of a leg are examined by a vascular doctor according to standard procedure based on pre-test clinical probability (PTCP) assessment, D-dimer assay and a CUS limited to the proximal deep veins. Those in whom a proximal DVT is excluded and have intermediate/high PTCP or altered D-dimer level are eligible for the study. The included patients are immediately submitted to an extensive echo-color-Doppler examination of calf deep veins by a different vascular doctor and results are closed in an envelope that will be open after three months (or before if necessary). In the meantime, patients will follow the standard diagnostic procedure: they receive an appointment to come back in 5-7 days for a further CUS examination, or even before in case of worsening of symptoms/signs. All the included patients receive a telephone call after three months to exclude possible complications.

Study Timeline

• Study Start: 2005-09
• Study First Submitted: 2009-01-02
• Study First Submitted QC: 2009-01-02
• Study First Posted: 2009-01-05
• Primary Completion: 2009-09
• Study Completion: 2009-09
• Status Verified: 2021-03
• Last Update Submitted: 2021-03-18
• Last Update Posted: 2021-03-22

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 500

Inclusion Criteria

• suspected deep vein thrombosis of a leg
• intermediate/high pre-test clinical probability or high D-dimer levels

Exclusion Criteria

• age < 18 years
• presence of proximal DVT
• suspected isolated iliac DVT
• symptoms/signs lasting from > 30 days
• presence of symptoms of pulmonary embolism
• pregnancy or puerperium
• full dose treatment with heparin or derivatives from > 1 day
• presence of superficial vein thrombosis
• limited life expectancy (< 6 months)
• geographically inaccessible location
• inability or refusal to give consent
• participation in other clinical studies

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
1	Ultrasound examination of leg veins	Outpatients with suspected leg DVT after exclusion of proximal DVT

Primary Outcome Measures

Name	Time	Method
Thrombotic complications (deep vein thrombosis and/or pulmonary embolism within three months from first examination	three months from first examination

Secondary Outcome Measures

Name	Time	Method
other vascular complications; how many isolated distal DVT will be diagnosed	three months from first examination

Trial Locations

Locations (2)

Angiology & Blood Coagulation, Policlinico S. Orsola-Malpighi; 🇮🇹 Bologna, Italy

Servizio di Fisiopatologia Vascoalre, Casa di Cura Villa Serena; 🇮🇹 Pescara, Italy