Incidence of silent abdominal DVT ‘not negligible’
MedWire News: Nearly 2% of patients undergoing abdominal computed tomography (CT) scan have clinically silent abdominal deep vein thrombosis (ADVT), Italian researchers report.
"The results of this study suggest that the prevalence of incidental ADVT is not negligible, in particular in patients with underlying major risk factors such as cancer and liver cirrhosis," say Walter Ageno (Ospedale Di Circolo, Varese) and colleagues.
There has been increasing interest on the clinical relevance of incidentally detected venous thrombosis, note the researchers in the Journal of Thrombosis and Haemostasis.
A number of studies have reported the prevalence of incidental pulmonary embolism (PE) in patients undergoing chest CT for reasons other than suspected PE, but few have investigated the prevalence and predictors of incidentally detected deep vein thrombosis (DVT) in patients undergoing abdominal CT.
To address this, Ageno and team reviewed all 2619 abdominal CT scans performed at Ospedale Di Circolo, Varese between September 2009 and March 2010. They were looking for the presence of ADVT, defined as the presence of an intraluminal filling defect on the CT scan.
The researchers report that 28 scans were specifically requested for suspected ADVT or were performed in patients with known ADVT. Of the remaining 2591 scans, 45 were positive for incidental ADVT, corresponding to an estimated prevalence of 1.74%
Twenty-one (46.7%) patients with ADVT were asymptomatic at the time of the test, whereas the remaining 24 (53.3%) had symptoms which apparently did not lead to suspicion of ADVT including abdominal pain, nausea and/or vomiting, diarrhea, or fever. None of the patients had a previous history of DVT.
When the researchers performed subgroup analyses they found that the prevalence of ADVT was highest among patients with liver cirrhosis, at 15.5%. It was 2.5% in patients with cancer, 1.8% in outpatients and 1.6% in inpatients. Excluding patients with liver cirrhosis and cancer reduced the estimated prevalence to 0.36%.
Multivariate analysis revealed that patients with cancer or liver cirrhosis were 3.2 and 14.7 times more likely to have ADVT, respectively, than those with neither condition.
Ageno et al conclude: "The prognostic role and the optimal therapeutic management of incidental ADVT remain unknown, but given the prevalence reported in our study we believe there is a strong rationale to support future studies aimed to specifically address these questions."
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By Laura Dean