Ultrasonographic assessment of the risk of free-floating thrombus detachment in the lower extremity deep veins in patients with fracture.

OBJECTIVE

To explore the ultrasonographic features and influencing factors of free-floating thrombus (FFT) detachment in the lower extremity deep veins (LEDVs) of patients with fractures.

METHODS

Clinical data of patients diagnosed with FFT in the LEDVs and implanted with an inferior vena cava filter (IVCF) in our hospital between July 2021 and August 2023 were retrospectively analysed. The patients were divided into the thrombus detachment group (the experimental group, n = 92) and the non-thrombus detachment group (the control group, n = 103) based on the presence of detached thrombus in the IVCF. The effects of thrombus echogenicity, floating degree, thrombus location, thrombin time, D-dimer and fibrinogen on thrombus shedding were analysed. The nomogram method was used to establish the model and predict the probability of delayed postoperative recovery.

RESULTS

The proportions of patients with extremely hypoechoic thrombus and medium and high floating degrees increased in the experimental group compared with those in the control group, and the differences between the two groups were statistically significant (P < 0.05). Extremely hypoechoic thrombus (P = 0.021, 95 % CI: 1.109-13.748) and high (P = 0.001, 95 % CI: 3.854-28.573) and medium floating degrees (P = 0.004, 95 % CI: 1.792-13.453) were risk factors for deep veins FFT (DV FFT) detachment. The results of receiver operating characteristic curve analysis showed that the area under the curve of the model was 0.893, with a 95 % CI of 0.856-0.937, indicating a high prediction accuracy.

CONCLUSION

Ultrasonographic parameters, including thrombus echogenicity and floating degree, are valuable in predicting DV FFT detachment in patients with traumatic fractures, providing references for IVCF implantation.