Don't Treat Superficial Thrombophlebitis Superficially
Abstract & Commentary
By Allan J. Wilke, MD, Professor and Chair, Department of Integrative Medicine, Ross University (Bahamas) Limited, Freeport, Grand Bahama, The Bahamas. Dr. Wilke reports no financial relationship to this field of study. This article originally appeared in the May 2010 issue of Internal Medicine Alert. It was edited by Stephen A. Brunton, MD, and peer reviewed by Gerald Roberts, MD. Dr. Brunton is Adjunct Clinical Professor, University of North Carolina, Chapel Hill, and Dr. Roberts is Assistant Clinical Professor of Medicine, Albert Einstein College of Medicine, New York, NY. Dr. Brunton serves on the advisory boards of Amylin, Kowa, Novo Nordisk, and serves as a speaker for Boehringer Ingelheim and Novo Nordisk. Dr. Roberts reports no financial relationships relevant to this field of study.
Synopsis: Superficial venous thrombosis is not a benign condition and deserves close attention.
Source: Decousus H, et al. Superficial venous thrombosis and venous thromboembolism: A large, prospective epidemiologic study. Ann Intern Med 2010;152:218-224.
In a prospective, observational study, these french vascular specialists enrolled 844 adults who presented to their primary care physicians (PCP) with symptomatic lower-limb superficial venous thrombosis (SVT). They excluded patients whose thrombi were shorter than 5 cm on compression ultrasonography, who were 10 days or less postoperative, who had sclerotherapy in the last 30 days, and who could not be followed up. The patients were evaluated immediately for deep vein thrombosis (DVT) by lower limb compression ultrasound (US) or, if symptomatic, for pulmonary embolism (PE). Patients without either (isolated SVT) were followed with a second lower limb US 8-14 days after initial presentation and at a visit at 3 months. The primary outcome was a confirmed thromboembolic event during the 3 months, defined as any lower limb DVT, asymptomatic recurrent SVT, asymptomatic SVT extension, or PE at the second US or any symptomatic event at the follow-up visit. The secondary outcome was mortality at 3 months.
The average age of the enrolled patients was 65. They were predominantly female (65%). The median time from presentation to their PCP to the vein clinic was 6 days. The long saphenous vein was involved 66% of the time. At enrollment, 210 (25%) patients had a DVT (198) and/or PE (33).
Six hundred thirty-four patients had an isolated SVT. Anticoagulation (oral or subcutaneous) was initiated in 540, and 584 were prescribed elastic compression hose. Sixty underwent vein stripping or ligation. Thirty-four subjects were excluded per protocol and 14 were lost to follow-up at 3 months. Of the remaining 586, 58 had a thromboembolic event (12 asymptomatic, 46 symptomatic). Seven were proximal DVTs and 3 were PEs. Two patients died, one from a probable PE, the other from metastatic cancer. Risk factors for a thromboembolic complication at 3 months, identified by multivariate analysis, were: being male (hazard ratio [HR], 2.63, 95% confidence interval [CI], 1.42-4.86), having a history of thromboembolism (HR, 2.18; 95% CI, 1.15-4.12), having a cancer history (HR, 3.12; 95% CI, 1.15-8.47), and not having varicosities (HR, 2.06; 95% CI, 1.01-4.25).
First, let's address some caveats. The patients' primary care physicians referred them to the researchers. Were there patients who presented to their PCPs who were not referred? If there were, presumably, their symptoms and signs were milder and did not progress, but we don't know. Although this is a large study, and I think we can trust its conclusions, it was halted before the predetermined number (1200) of patients needed were enrolled because enrollment was so slow. The CIs for the risk factors' HRs may have been more impressive if enrollment had been complete. The researchers excluded "small" SVTs, those shorter than 5 cm. Can we assume that small SVTs don't progress or are more benign? The study was funded by two pharmaceutical concerns and three French medical societies, but the authors state that none of the funding sources had any input into the study design.
What lessons should we take from this study? First, patients with an SVT will have a one in four chance of having a coincident DVT or PE. Second, in 3 months, despite anticoagulation and compression hose, one in 10 patients with an isolated SVT will have a complicating thromboembolic event. You might consider screening patients with large, symptomatic SVTs with compression US and be alert to signs and symptoms of PE. Since this was not a study of treatment, it's difficult to say what to do about isolated SVTs. It's possible that there may have been more complications if the patients had not been anticoagulated. At the very least, it would be prudent not to dismiss SVTs, to advise our patients about the symptoms of possible sequelae, and to follow them closely.