Contribution of Lower Limb Venous Colour Doppler Ultrasound in the Diagnosis of Pulmonary Embolism Recurrence

Venous thromboembolic disease is a clinical entity including pulmonary embolism (PE) and deep vein thrombosis (DVT). It is a chronic disease with 30% recurrence rate at 10 years. In patients with recurrent PE clinical suspicion, an objective and accurate diagnostic method/strategy is warranted to exclude or confirm a PE new episode diagnosis and to decide on treatment initiation. Recurrent PE diagnosis raises several issues related to the limitations of clinical scores, D-dimer testing, and diagnostic imaging used for a first episode diagnosis. Most importantly, residual obstruction on chest imaging reported in more than 50% of cases at 6 months can make it difficult to distinguish between an old and a new thrombosis in the absence of possible comparison with a previous imaging carried out under the same modalities. There are currently few recommendations about the diagnostic strategy for patients with a recurrent PE clinical suspicion and these recommendations are not very consistent due to the lack of a validated strategy. None of current guidelines have included imaging-detectable lower-limb DVT within the strategies despite a reported high prevalence of PE-associated DVT. In one study using venography, 82% (95% CI 76.5 - 86.9) of angiographically-proven PE patients had an associated proximal or distal deep vein thrombosis, of which 42% were asymptomatic. In another study using lower-limb venous ultrasound, a proximal or distal DVT was detected in 93% (95% CI 85-97) of patients with PE.