Site and clinical outcome of deep vein thrombosis of the lower limbs: an epidemiological study.

Clinical outcomes of patients diagnosed with venous thromboembolic disease (VTED) have rarely been assessed on large series of patients from single institutions. This was work based on our practice to routinely screen all suspected pulmonary embolism (PE) and deep venous thrombosis (DVT) patients with bilateral proximal and distal venous US was designed to evaluate survival, recurrence and cancer occurrence in patients diagnosed with symptomatic or asymptomatic DVT and to assess their relationship with the site of the DVT (proximal vs. distal, bilateral vs. unilateral). Our study is based on the cross-matching of the VTED register of the Grenoble University Hospital with the local Cancer Register and community mortality data. Survival analyses were performed with the Kaplan-Meier method; prognostic variables were tested using the log-rank test. A total of 1913 patients with a DVT of the lower limbs from 1993 to 1998 were included (57% women; mean age, 69 years). Of these, 1018 patients were diagnosed with proximal DVT (156 bilateral) and 895 distal DVT (112 bilateral). PE was associated in 760 patients. Patients with PE and no detected DVT were not included. At 2 years, adjusted survival rates were 80% in patients with unilateral-distal DVT, 67% in bilateral-distal, 72% in unilateral-proximal and 65% in bilateral-proximal DVT patients. The cumulated VTED recurrence rates were 7.7% in unilateral-distal DVT, 13.3% when DVT was bilateral-distal, 14% when unilateral-proximal and 13.2% when bilateral-proximal. The rate of new cancer was 6.4% in unilateral-distal DVT, 10.8% when it was bilateral-distal, 6.5% when unilateral-proximal and 6.1% when bilateral-proximal. Based on a large series of unselected patients, our results show that the site of the DVT and principally the bilaterality provides important prognostic information that may be used in the setting up of medical strategies.