Clotting in veins close to skin may be associated with more dangerous deep-vein blood clots

About one-fourth of patients with superficial vein thrombosis—clotting in blood vessels close to the skin—also may have the life-threatening condition deep vein thrombosis, according to a report in the July issue of Archives of Dermatology, one of the JAMA/Archives journals. "Superficial vein thrombosis is a common disease that most often affects the veins of the leg but can also be found in other locations," the authors write as background information in the article. Different risk factors have been reported, many of which are the same as risk factors for deep vein thrombosis—varicose veins, thrombophilia (a disorder in which the blood clots too easily), use of oral contraceptives, trauma, malignancy or a period of immobility. "In the past, not much interest has been focused on superficial vein thrombosis because of its generally benign course. However, recent investigations showed an unsuspected association of superficial vein thrombosis with deep vein thrombosis and thromboembolism [blockage of a blood vessel by a clot that has broken apart]."

Barbara Binder, M.D., of the Medical University of Graz, Austria, and colleagues studied 46 consecutive patients (32 women and 14 men) with superficial vein thrombosis between November 2006 and June 2007. All patients underwent color-coded duplex sonography, an imaging test, to confirm superficial vein thrombosis and exclude or detect deep vein thrombosis. Participants also reported their history of clotting events, use of oral contraceptives and compression stockings, any recent immobilization and active malignant disease. Laboratory tests included D-dimer levels, a measure of protein fragments that tends to be elevated in patients with deep vein thrombosis.

Deep vein thrombosis was detected in 24 percent of patients with superficial vein thrombosis and was usually asymptomatic. Deep vein thrombosis occurred in the same leg as superficial vein thrombosis in 73 percent of the patients, in the other leg in 9 percent and in both legs in 18 percent. "The calf muscle veins were most commonly involved," the authors write. "In all patients with deep vein thrombosis, the superficial vein thrombosis was located on the lower leg and the D-dimer findings were positive."

"Generally, superficial vein thrombosis is regarded as a condition with an uncomplicated course and usually is not considered to be a severe or life-threatening disease. However, the occurrence of concomitant deep vein thrombosis and/or pulmonary embolism [blood clot that travels to the lungs] may lead to severe complications," they continue. "The results of this study indicate that concurrent deep vein thrombosis is more likely when superficial vein thrombosis affects the lower leg. In these cases, the deep veins should be assessed by color-coded duplex sonography (from the inguinal [groin] region to the ankle) to exclude or confirm acute deep vein thrombosis."

Source: JAMA and Archives Journals