E Bowen, L Haupt
The low prevalence of IDDVT in the study cohort suggests that a proximal-only ultrasound approach can be adopted. Additionally, black African and mixed-race ethnicity, as well as male sex, were associated with a higher incidence of PDVT. Further prospective evaluation of the propagation rate of IDDVTs might advocate for tailored ultrasound approaches in different demographic groups.
BACKGROUND: Isolated distal deep vein thrombosis (IDDVT) is thrombosis that occurs in the lower-limb venous system, limited to the calf veins, with no extension into the popliteal veins. Proximal propagation or proximal DVT (PDVT) has well-defined treatment protocols in which anticoagulation shows clear benefit. IDDVT, however, does not always require treatment because the risk-benefit relationship of anticoagulation is not well established. The divergence in IDDVT treatment has led to two ultrasound approaches: whole-leg and proximal- only ultrasound, with repeat examination when indicated.
OBJECTIVE: To investigate the prevalence of IDDVT using the current ultrasound approach at Universitas Academic Hospital, in order to advise on possible adaptation and tailored approaches in distinct subpopulations.
METHODS: A retrospective file review of ultrasound investigations performed from 1 January 2015 to 31 December 2020 at the vascular suite in Universitas Academic Hospital, Bloemfontein, South Africa. Demographic data, HIV status and the anatomical site and anatomical extent of the thrombosis were collected.
RESULTS: In total, 2 208 files were reviewed, which included 1 203 (54.5%) cases negative for DVT, with an alternative diagnosis possible in 113 (9.4%) of the negative cases. Of the 1 005 (45.5%) positive cases, 983 had adequate data for analysis, with 845 (86.0%) PDVT and 138 (14.0%) IDDVT cases. A female predominance was observed, with a male-to-female ratio of 1:2.02. Black African and mixed-race patients had significantly less IDDVT than white patients. Nearly two-thirds (66.0%) of the patients were HIV positive. However, HIV as a risk factor for PDVT did not meet statistical significance (p=0.053).
CONCLUSION: The low prevalence of IDDVT in the study cohort suggests that a proximal-only ultrasound approach can be adopted. Additionally, black African and mixed-race ethnicity, as well as male sex, were associated with a higher incidence of PDVT. Further prospective evaluation of the propagation rate of IDDVTs might advocate for tailored ultrasound approaches in different demographic groups.