D-dimer monitoring combined with ultrasonography improves screening for asymptomatic venous thromboembolism in acute spinal cord injury

Abstract

Objective: We compared screening methods for asymptomatic venous thromboembolism (VTE) in patients with acute spine and spinal cord injuries (SCI). Patients were screened by D-dimer monitoring alone (DS group) or by D-dimer monitoring combined with ultrasonography (DUS group).Design: Prospective cohort study.Setting: One department of a university hospital in Japan.Participants: 114 patients treated for acute SCI between 2011 and 2017.Interventions: N/A.Outcome Measures: D-dimers were measured upon admission and 1, 3, 5, 7, and 14 days thereafter. DUS-group patients also underwent an ultrasound 7 days after admission. If ultrasonography indicated deep venous thrombosis (DVT), or if D-dimer levels increased to ≥ 10 µg/mL, the patient was assessed for VTE, including DVT or pulmonary embolism (PE), by contrast venography. We analyzed the incidence of VTE detected in the DS and DUS groups.Results: In the DS group, D-dimers were elevated (≥ 10 µg/mL) in 15 of 70 patients (21.4%), and 9 of the 15 had asymptomatic VTE (12.9%, DVT 11.4%, PE 5.7%). In the DUS group, one patient developed VTE on day 4, and D-dimers were elevated in 13 of 43 patients (30.2%), ultrasonography indicated DVT in 12 patients (27.9%), and asymptomatic VTE was diagnosed in 12 patients (27.9%, DVT 27.9%, PE 4.7%). The DUS group had a higher incidence of DVT (P = 0.002) and VTE (P = 0.042) than the DS group.Conclusions: Combined D-dimer and ultrasound screening in patients with acute SCI improved the detection of VTE, including PE, compared with D-dimer screening alone.