High vs. low doses of low-molecular-weight heparin for the treatment of superficial vein thrombosis of the legs: a double-blind, randomized trial.

In contrast with extensive information on the management of deep vein thrombosis of the lower extremities, little is known on the most appropriate treatment of the superficial vein thrombosis (SVT). In a multicenter, prospective, controlled, double-blind, double-dummy clinical trial, 164 consecutive patients with acute SVT of the great saphenous vein were randomized to receive the s.c. administration of either fixed prophylactic doses (2850 a-Xa IU) or body-weight adjusted therapeutic doses of nadroparin once daily for 1 month. The main study outcome was to compare the rate of asymptomatic and symptomatic extension of SVT and/or venous thromboembolic (VTE) complications during a 3-month follow-up period. Of the 81 patients randomized to the prophylactic doses, seven [8.6%; 95% confidence interval (CI), 3.5-17.0] developed SVT progression or VTE complications as compared with six of the 83 (7.2%; 95% CI, 2.8-15.1) allocated to the treatment group (absolute difference, 1.4; 96% CI, -6.9 to 9.7; P = 0.74). No patient in either group developed major bleeding. Our findings suggest that therapeutic doses of low-molecular-weight heparin, administered for 1 month in patients with SVT of the greater saphenous vein do not improve results obtained by prophylactic doses, administered for the same period, over a 3-month follow-up period.