Background: In patients with superficial venous thrombosis (SVT) co-existence of deep venous thrombosis (DVT) can be present. Varicosities are considered as a risk factor for both SVT and DVT separately. However, current evidence is contradictory whether varicosities are associated with an increased or reduced prevalence of concomitant DVT in patients with SVT.
Objectives: To determine the diagnostic value of both presence and absence of varicosities in the detection of concomitant DVT in non-hospitalized patients with SVT.
Methods: In MEDLINE and EMBASE, a systematic search was performed to collect all published studies on this topic. The selected papers were critically appraised. By diagnostic 2 × 2 tables prior probabilities and predictive values were computed.
Results: Six relevant articles were identified. The prior probability of concomitant DVT in patients referred from primary care to the outpatient clinic varied between 13 and 34%. In five studies, absence of varicosities was related to a higher probability of concomitant DVT (33-44%) compared to a presence of varicosities (3-23%). The sixth study showed an inversed, non-significant association: DVT was present in 21% of patients with SVT on non-varicose veins versus in 35% of patients with SVT on varicose veins.
Conclusion: In five out of six studies on patients with SVT in outpatient settings, absence of varicosities was related to a higher probability of concomitant DVT. Further research is needed to determine whether an assessment of varicosities in general practice could result in an improved selection of patients who require additional imaging to detect or exclude DVT.
Keywords: deep venous thrombosis; diagnosis; superficial venous thrombosis; varicosities.