Abstract: Objective: To investigate the clinical characteristics of PICC-related upper extremity asymptomatic venous thrombosis in cancer patients, and to provide theoretical basis for the early prevention of venous thrombosis. Methods: A total of 127 cancer patients with PICC catheterization from April 2017 to October 2018 were selected. Doppler ultrasound was used to examine the puncture point, 2cm above the puncture point, 10cm above the elbow fossa and armpit of the upper extremity on the side of the catheter. The examinations were before catheterization and on days 2nd, 7th, 14th, 21st, 28th, 35th, and 42nd after catheterization. Results: The incidence of asymptomatic venous thrombosis was 48.82% and the median time of thrombosis was 3 day. A total of 81 thrombosis were detected in 62 patients, of which deep vein thrombosis accounted for 23.46% and superficial vein thrombosis accounted for 76.54%. The rates of thrombus classification (I, II, III) were 51.85%, 37.04%, 11.11% respectively. Logistic regression analysis showed that ECOG (OR=9.185, 95%CI 4.770-28.262, P<0.001), venous flow velocity (OR=0.577, 95%CI 0.506-0.858, P=0.002) were associated with the development of asymptomatic thrombosis. ROC curve analysis of the risk value of venous flow velocity was 4.78 cm/s (AUC is 0.739, 95%CI 0.649-0.830). Conclusion: The incidence of PICC-related asymptomatic thrombosis in cancer patients is high. It mostly occurs 2-10cm above the puncture site. It is suggested that pre-catheterization screening and intervention measures should be conducted in high-risk population with low activity and venous flow rate ≤4.78cm/s to prevent the occurrence of asymptomatic venous thrombosis.

Key words: cancer patients; PICC; catheter-related venous thrombosis; asymptomatic venous thrombosis