Purpose. - To determine the prevalence of acute deep venous thrombosis (DVT) and identify the risk factors and clinical variables for the appropriate use of color flow duplex scanning (CDS) in patients with suspected pulmonary embolism. Methods. - From January 1, 1999, to July 31, 1999, we prospectively analyzed the clinical indications and results of 206 patients with suspected pulmonary embolism undergoing lower extremity CDS for the evaluation of suspected DVT. Twenty-seven separate clinical variables were investigated as predictors for the presence of acute DVT: 12 risk factors as proposed by the Society for Vascular Surgery, North American Chapter, International Society for Cardiovascular Surgery (SVS/ISCVS) reporting standards and 15 clinical signs and symptoms, which have been documented previously in the literature. Patients were then placed into four groups based on the presence or absence of significant clinical variables: group 1 (152 patients), no risk factors or clinical signs and symptoms; group 2 (5 patients), risk factors and clinical signs and symptoms; group 3 (21 patients), risk factors only; group 4 (28 patients), clinical signs and symptoms only. The prevalence of DVT was determined for each group. Results. - Acute DVT was detected in 20 patients (9.7%) who underwent CDS. Univariate analysis was performed and 3 clinical variables were found to be significantly related to acute DVT: history of immobilization (P = .02), calf circumference difference ≥ 2 cm (P = .002), and unilateral leg swelling (P = .004). The prevalence of acute DVT in groups 1, 2, 3, and 4 were 6, 40, 19, and 18%, respectively. There was a significant difference in the prevalence of DVT between the group without significant risk factors or clinical signs and symptoms and the groups with significant risk factors and clinical signs and symptoms (P = .004). Conclusion. - The prevalence of acute lower extremity DVT in patients with suspected pulmonary embolism is low. However, the presence of the combination of three clinical variables significantly increases the prevalence of DVT compared with patients with no risk factors or clinical indications. We suggest that the value of CDS as the initial study for the diagnosis of acute DVT in patients with suspected pulmonary embolism and no significant risk factors or clinical signs and symptoms for DVT is limited and that the use of CDS as an initial screening study should be reserved for those patients with significant risk factors and clinical signs and symptoms. By utilizing these general guidelines, we can identify patients at decreased risk for acute DVT, improve the diagnostic yield for pulmonary embolism, and therefore reduce the number of unnecessary color flow duplex scans performed in patients with suspected pulmonary embolism.
|Original language||English (US)|
|Number of pages||8|
|Journal||Journal of Vascular Technology|
|State||Published - Jul 24 2001|
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging
- Cardiology and Cardiovascular Medicine