Non-thrombotic abnormalities on lower extremity venous duplex ultrasound examinations

Assessment of Lower Limb Deep Vein Thrombosis: Characterization and Associated Risk Factors Using Triplex Doppler Imaging

Background

Deep vein thrombosis (DVT) is a common health problem. Accurate diagnosis of DVT is essential to avoid potentially fatal acute consequences of pulmonary embolism.

Aim

The study aims to assess deep venous thrombosis (DVT) of the lower limbs and to analyze the related risk factors.

Methods

This is a retrospective study including 60 patients who were examined using Triplex Doppler imaging. The patients were referred to the imaging departments with symptoms of lower limb DVT. The risk of DVT was expressed as an odds ratio (OR) with 95% confidence interval. Multiple logistic regression analysis was used to detect the independent risk factors. P value <0.05 was considered a significant statistic.

Results

Among the Saudi patients in Najran, acute DVT was more prevalent than chronic one (56.7% vs 38.3%), while subacute is less frequent (5%). DVTs are more prevalent in females than males (60% vs 40%) and most commonly affect patients older than 40. DVTs affect the left lower limb veins more than the right limb (75% vs 15%) and are less frequent on both sides (10%). The left popliteal vein (PV) and left common femoral vein (CFV) were the most common sites for acute DVTs. Binary logistic analysis revealed the independent risk factors for developing lower extremity DVT; malignancy (OR = 2.84, 95% CI = 0.518-15.513), surgery (OR = 2.66, 95% CI = 0.411-17.281), trauma (OR = 2.30, 95% CI = 0.452-11.658), and diabetes and hypertension (OR = 1.53, 95% CI = 0.335-6.969).

Conclusion

Acute lower limb DVT was more prevalent than chronic one. Malignancy, surgery, trauma, diabetes mellitus, and hypertension were the most common risk factors for lower limb DVTs. Left popliteal and left common femoral veins were the most common sites of acute DVTs.

Incidence of Non-thrombotic Diagnoses Following Venous Duplex Ultrasound at a Community Emergency Department

Background: When used as a diagnostic aid for diagnosing deep vein thrombosis (DVT), venous duplex ultrasound (US) may reveal non-thrombotic findings in those with acute extremity pain. The objective of this study was to determine the prevalence and predictors of non-thrombotic findings on venous duplex US at a community emergency department.

Methods: A retrospective chart review of all adult patients who presented to a community emergency department who underwent either an upper or lower extremity venous duplex US for the evaluation of DVT from June 1, 2019, to September 15, 2020. All US studies were completed by certified sonographers and interpreted by board-certified radiologists. Two trained research assistants manually abstracted patient demographics and US findings. Data were analyzed using the chi-square statistic for categorical variables and the student's independent t-test for continuous variables. Multivariate binomial regression was used to identify independent predictors of non-thrombotic results on venous duplex US.

Results: A total of 1,448 venous duplex US were obtained during the study period with 126 DVTs being diagnosed. A total of 1071 US had no acute abnormality and 252 had non-thrombotic findings. All non-thrombotic findings were found in the lower extremity. Of those with non-thrombotic findings, the most common diagnoses included edema (34.9%, 88/252), Baker’s cyst (22.6%, 57/252), and an unspecified fluid collection (16.3%, 41/252). Patients with non-thrombotic findings were more likely to have a history of atrial fibrillation (p=0.001) or hypertension (p=0.001), be older than the age of 70 (p=0.042), or have a history of using illicit drugs (p=0.003). Females were less likely to have non-thrombotic findings.

Conclusion: In this single-site study, non-thrombotic findings were present in 23.5% of all venous duplex US completed at a community emergency department. These findings are more common in the elderly, those with cardiovascular disorders, and those who have used illicit drugs.

Prevalence and predictors of alternative diagnoses on whole-leg ultrasound negative for acute deep venous thrombosis

Background

To investigate the prevalence, spectrum, and predictors of alternative diagnoses explaining leg symptoms in patients negative for suspected acute deep venous thrombosis (DVT), which can be detected with whole-leg ultrasound.

Methods

We retrospectively analyzed a cohort of 789 patients (median age 70 years, 50.6% women) evaluated with a whole-leg ultrasound examination for suspected acute DVT within one year. All findings in the radiology report were analyzed and electronic chart review was performed to collect clinical information.

Results

Ultrasound was negative for acute DVT in 531 patients (67.3%). Among these, alternative diagnoses explaining leg symptoms were seen in 349 patients (65.7%). The most frequent alternative diagnoses were chronic venous insufficiency (147 patients, 27.7%), followed by lymphedema (48 patients, 9.0%) and chronic post-thrombotic changes (41 patients, 7.7%). Patients with alternative diagnoses were older (median 71 vs. 66 years, p = 0.0226), as well as more likely to present with leg swelling (39.5% vs. 23.1%, p = 0.0002), difference in leg circumference (25.5% vs. 14.8%, p = 0.0055) and redness (7.7% vs. 2.7%, p = 0.0213) than patients without alternative diagnosis. Independent predictors of finding alternative diagnoses on whole-leg ultrasound were older age (odds ratio 1.014 per year, p = 0.0119), leg swelling (OR 1.949, p = 0.0020) and history of previous DVT (OR 2.235, p = 0.0154).

Conclusions

Alternative diagnoses explaining leg symptoms can be detected on whole-leg ultrasound in two thirds of patients with no evidence of acute DVT. Our data supports performing a comprehensive ultrasound evaluation beyond the venous system, particularly, in older patients, who present with leg swelling and a past history of DVT.