# The Value of Ultrasound Combined With Thromboelastography in Dynamic Monitoring of Thrombosis in Patients on Maintenance Hemodialysis With Arteriovenous Fistulas

## TL;DR

This study shows that combining ultrasound and thromboelastography improves detection of abnormal blood flow in dialysis patients with arteriovenous fistulas.

## Contribution

The study introduces a combined diagnostic approach using TEG and ultrasound for dynamic thrombosis monitoring in hemodialysis patients.

## Key findings

- TEG indicators were significantly higher in the abnormal blood flow group compared to the normal group.
- Combined TEG and ultrasound diagnosis showed higher sensitivity and a larger AUC than individual methods.
- The combined diagnostic model had high sensitivity but low specificity for detecting abnormal blood flow.

## Abstract

Objective: The objective of this study was to explore the value of dynamic detection of thrombelastogram (TEG) combined with ultrasound in thrombus formation in patients on maintenance hemodialysis (MHD) with arteriovenous fistula (AVF).

Methods: A total of 98 patients undergoing MHD with an upper limb forearm AVF who met the diagnostic criteria were randomly selected from our hospital. Three cases were lost to follow-up, resulting in 95 participants. According to the blood flow at the fistula site, there were 26 cases in the abnormal blood flow group and 69 cases in the normal blood flow group. TEG and ultrasound examinations were performed on the same day before and after the fistula creation, once every two days, for a total of five consecutive tests; 3 mL of peripheral venous blood was drawn for TEG examination. The differences in TEG indicators (R value, K value, α angle, and MA value) between the two groups were compared. Linear regression and binary logistic regression were used to compare TEG indicators, ultrasound, and the combined diagnosis of abnormal blood flow at the fistula site, along with sensitivity and specificity, and the receiver operating characteristic (ROC) curve.

Results: The TEG indicators for the abnormal blood flow group and the normal blood flow group were 3.72±1.36 and 7.34±1.40, 0.72±0.34 and 2.08±0.44, 78.77±9.14 and 61.78±5.41, 74.96±10.63 and 58.63±5.68, respectively, with significant differences between the two groups (all P < 0.05). The variance inflation factor (VIF) for TEG indicators and ultrasound diagnostic single indicators was 3.627, 4.479, 3.400, 3.289, 3.9789 (all < 5), indicating no multicollinearity, while the combined diagnostic model had a VIF of 6.334 (> 5), indicating the presence of multicollinearity.

Binary logistic regression analysis showed that TEG indicators, ultrasound diagnosis, and combined diagnosis abnormalities (OR = 1.244, 1.202, 1.316, 1.374, 1.460, 1.547, all P < 0.001) were independent risk factors for abnormal blood flow at the AVF site. The sensitivity and specificity of TEG, ultrasound diagnosis, and combined diagnosis were 76.9% and 4.3%, 88.5% and 4.3%, 73.1% and 4.3%, 76.9% and 2.9%, 88.5% and 4.3%, 96.2% and 0.0%, respectively. The combined diagnosis had high sensitivity and low specificity, but the differences were not statistically significant (all P > 0.05). The area under the ROC curve for the combined diagnosis was significantly larger than that for TEG indicators and ultrasound diagnosis. The dialysis blood flow (ml/min) before and after treatment in the abnormal blood flow group was 153.5±16.1 and 322.6±38.6, respectively, with significant differences between them (t=18.402, P < 0.05).

Conclusion: All TEG indicators in the abnormal blood flow group of MHD-AVF were higher than those in the normal blood flow group. TEG indicators and ultrasound examination in MHD-AVF patients are risk factors for abnormal blood flow at the fistula site. TEG combined with ultrasound has better collinearity, high sensitivity, low specificity, and the AUC is higher than that of separate TEG and ultrasound diagnoses. The combined diagnosis of TEG and ultrasound can improve the diagnostic rate of abnormal blood flow at the MHD-AVF fistula site.