Biodegradable PTX-PLGA-coated magnesium stent for benign esophageal stricture: An experimental study.

Biodegradable stents can degrade step by step and thereby avoid secondary removal by endoscopic procedures in contrast to metal stents. Herein, a biodegradable composite stent, a magnesium (Mg)-based braided stent with a surface coating of poly (lactic-co-glycolic acid) (PLGA) containing paclitaxel (PTX), was designed and tested. By adding this drug-loaded polymer coating, the radial force of the stent increased from 33 Newton (N) to 83 N. PTX was continuously released as the stent degraded, and the in vitro cumulative drug release in phosphate-buffered saline for 28 days was 115 ± 13.5 µg/mL at pH = 7.4 and 176 ± 12 µg/mL at pH = 4.0. There was no statistically significant difference in the viability of fibroblasts of stent extracts with different concentration gradients (P > 0.05), while the PTX-loaded stents effectively promoted fibroblast apoptosis. In the animal experiment, the stents were able to maintain esophageal patency during the 3-week follow-up and to reduce the infiltration of inflammatory cells and the amount of fibrous tissue. These results showed that the PTX-PLGA-coated Mg stent has the potential to be a safe and effective approach for benign esophageal stricture. STATEMENT OF SIGNIFICANCE: We designed a biodegradable composite stent, having poly (lactic-co-glycolic acid) (PLGA) containing paclitaxel (PTX) coated the surface of the magnesium (Mg)-based braided stent. We evaluated in vitro and in vivo characteristics of the Mg esophageal stent having a PLGA coating plus a variable concentration of PTX in comparison with the absence of PTX PLGA coating. The PTX PLGA stents exerted higher radial force than stents without coating, degraded more quickly in an acid medium, and effectively promoted fibroblast apoptosis in vitro experiments. In a rabbit model of caustic-induced esophageal stricture, there was an increased lumen and decreased inflammation of the esophageal wall in the animals stented with PTX-PLGA versus the sham group, indicating a potential approach for benign esophageal stricture.

Venous thromboembolism in non-COVID-19 population during the pandemic: a nationwide multicenter retrospective survey.

Impact of pandemic on the incidence of venous thromboembolism (VTE) in non-COVID-19 patients is undetermined. Thus, a nationwide multicenter retrospective survey was conducted to evaluate the disease burden in non-COVID-19 population. This multi-center survey involved 94 hospitals from 24 provinces in the mainland of China, and collected data on non-COVID-19 patients admitted to the radiology departments due to VTE between January 24 and April 16, 2020. Baseline characteristics, VTE risk factors, clinical manifestations and the treatments were compared with those in the same period of 2019. 3,358 patients with VTE from 74 hospitals were included in this study (1,458 in 2020, 1,900 in 2019). Most aged ≥ 50 years (80.6% in the pandemic, 81.2% in 2019). The number of patients aged 30-39 years increased from 3.9% in 2019 period to 5.8% in the pandemic (p = 0.009). Among the VTE risk factors, the rate of decreased activity increased significantly in the pandemic, and was much higher than that in 2019 (30.7% vs 22.6%, p < 0.0001). Under the risk of decreased activity, patients with comorbidities chronic diseases, especially diabetes, showed significantly a higher incidence of VTE (30.4% vs 22.0%, p < 0.0001). In the pandemic period, fewer patients were treated with anticoagulation alone (33.5% vs 36.7%, p = 0.05), and more underwent inferior vena cava filter (IVCF) implantation, compared with those in 2019 (66.5% vs 63.2%, p = 0.046). The pandemic increased the VTE risk of decreased activity among the non-COVID-19 population. Patients with comorbidities, especially diabetes, have a significant higher risk of VTE during the pandemic.