Cancer patients have a high incidence of PICC-related venous thrombosis (PICC-RVT) in the early stage of catheterization. PICC placement involves direct damage to the inner wall of blood vessels. At the same time, due to multiple factors, such as the patient’s own state, thrombosis can form on the inner wall of the blood vessel of the peripheral central vein catheter or the wall of the catheter attachment [15]. The results showed that the incidence of PICC-RVT in cancer patients during catheter insertion reached 24.9%, of which the incidence of thrombosis within 1 month and 3 months of catheter insertion was as high as 47.8% and 31.1%, respectively, which was higher than that of an indwelling time of more than 6 months (23.9%), which was consistent with the study by Chopra et al. [1]. However, the incidence was higher than that reported in other studies and might be underestimated. Limb swelling, discomfort, and erythema are typical clinical manifestations of PICC-related thrombosis, but some patients do not exhibit typical clinical symptoms when they have asymptomatic thrombosis [16]. This could make it clinically difficult to determine the optimal period of thrombolysis or anticoagulation. The reason may be that the vascular endothelium is destroyed during PICC catheterization [17], affecting blood flow, enhancing platelet adhesion, and activating procoagulant factors in the body, which may cause hypercoagulability and asymptomatic thrombosis in the early stage.
The incidence of PICC-RVT varied at different indwelling times, showing a downward trend. The duration of PICC catheterization ranged from 1 month to 1 year. Most studies only investigated the incidence of thrombosis before removal of PICC, ignoring the high risk of developing PICC-related thrombus during catheterization [18]. The lower incidence of thrombosis after 6 months of catheter insertion compared with the incidence within 1 month may be due to organic detachment of thrombus or absorption by hemodilution during indwelling, and health care workers should strengthen thrombosis prevention, such as weekly or monthly routine Doppler ultrasound. It has been recommended that medical staff standardize early fist exercises and hydration in cancer patients with PICC catheterization based on evidence-based studies, improve blood circulation in cancer patients, and increase health education to prevent and reduce the incidence of thrombosis [19, 20].
Male cancer patients older than 69 years with a BMI < 18.5 were at higher risk of PICC-RVT. Patients with many factors, such as advanced disease and immutable factors, are harder to identify, but high-risk patients can be targeted for prevention, receive good education in advance, receive more attention, and regularly undergo color ultrasound screening to avoid missing the occurrence of thrombosis, causing greater risk. In this study, the catheter-related factors were controlled within a certain range, and the single-lumen Bard 4 Fr catheter was selected, which had a P > 0.05 in this study. The results of this study showed that older age, male sex, and BMI were risk factors for PICC-RVT. Patients older than 69 years tend to have aging vascular walls and higher blood concentrations, which, combined with generally less exercise and weakened metabolism, result in relatively slow blood flow [21, 22]. Men have a higher risk of thrombosis than women, consistent with Cohen's study [23]. PICC-related thrombosis in patients with a BMI < 18.5 was higher than that in patients with a BMI > 24, which was inconsistent with the results of the study by Ban [24], possibly in the other study, the entire population was overweight/obese [25]. And in this study the patients were cachexic, had poor appetite, and required long-term infusion of viscous substances such as nutrient solution, and their thick and slow-flowing blood was more likely to develop venous thrombosis. Clinical medical staff should strengthen the awareness of thrombosis prevention in patients who are elderly, male and emaciated to avoid increasing the pain and economic burden of patients and affecting their treatment and quality of life.
This study showed that chemotherapy was a protective factor for PICC-RVT in cancer patients. This is inconsistent with Lyman's [26] findings. The reason was that PICC is a deep vein catheterization technology introduced from the peripheral veins and terminated in the central vein, which is suitable for medium- and long-term intravenous infusion, cancer chemotherapy, and parenteral nutrition and can effectively avoid direct contact between chemotherapy drugs and arm veins, reduce vascular endothelial damage, prevent drug stimulation of blood vessels, and ensure the safety of infusion [27]. Compared with PICCs used for chemotherapy and nutrition therapy for patients with terminal cancers, components in intravenous nutrition, such as milk fat, will result in more viscous blood and slow blood flow and increase the occurrence of catheter-related thrombosis [28]. Moreover, patients receiving chemotherapy in this study had fewer serious adverse reactions, such as nausea and vomiting, and cancer patients receiving chemotherapy had higher compliance with thrombosis prevention procedures [22]. Therefore, for patients receiving end-stage intravenous nutrition therapy, it was suggested that clinical medical staff flush the tube and dilute the drug concentration in a timely manner, reducing the occurrence of PICC-RVT.
Clinical implications and limitations
This was a retrospective study conducted only on cancer patients in a tertiary hospital, and the representativeness and practical value of the study need to be further verified. In this study, the risk factors affecting PICC-RVT in cancer patients were analyzed, and a large amount of data is needed to improve the conclusions of this experiment. It was expected that the prediction model of PICC-RVT could be constructed and verified. Despite the above limitations, this study can guide clinical workers to pay more attention to cancer patients with a high risk of PICC-RVT at early indwelling times. These patients would benefit from timely screening for PICC-RVT and prevention information in advance to avoid thrombosis, reduce thrombosis-related costs, avoid delayed PICC removal, receive medication treatment, undergo repeated color ultrasound, and reduce patient anxiety and fear of catheterization.