Association of Post-Thrombotic Changes with Disease Severity in Patients Presenting with Symptomatic Calf Vein Thrombosis

Background/Objectives: This prospective study was designed to evaluate the natural history of isolated calf deep vein thrombosis (ICDVT) in relation to their patterns and distribution. Methods: 117 limbs in 104 patients, with isolated symptomatic calf vein thrombosis were included in the study. These were objectively diagnosed with ultra-sound. The distribution and extent of the initial DVT was recorded in detail. Patients with a documented episode of prior DVT or those having thrombus in the popliteal vein or higher were excluded. Follow-up at 3-48 months was performed with clinical examination and ultrasound. Ultrasound examination was done with the patient in the standing po-sition to ensure optimal testing for detecting post-thrombotic changes. Affected venous segments were classified as having an occlusion, complete recanalization, partial re-canalization, with or without reflux. Results: At 1 year, out of 98 limbs analyzed, most (99%) had recanalization of their calf vein thrombosis; 53% (n=52) had complete, 46% (n=45) had partial, and 1% (n=1) had no recanalization. Ultrasound studies of those limbs showed reflux (R) in 22% (n=22), obstruction (O) in 9% (n=9), R + O in 33% (n=32), and normal findings in 36% (n=35) of limbs. Only 17% of limbs had signs of edema (CEAP 3), 2% had skin changes (CEAP 4) and 0% had any signs of ulcers (CEAP 5,6). Of these findings, only 14 patients experienced persistent symptoms at 1 year. Conclusions: Pa-tients with symptomatic calf vein DVT generally have good clinical outcomes, with most being asymptomatic, and having mild disease. While small deterioration is seen up to 4 years, few limbs developed skin changes. The presence of reflux in calf veins does not appear to be a significant predictor of severe disease development in the medium term.