Self-expanding covered metallic stents as a transition to silicone stent implantation in management of severe post-tuberculosis bronchial stenosis.

BACKGROUND AND AIMS: Post-tuberculosis bronchial stenosis (PTBS) is one of the most common complications of tracheobronchial tuberculosis. Silicone stent serves as a major treatment for maintaining airway patency. However, silicone stent placement remains a large challenge in patients with severe cicatricial PTBS. Our objective was to evaluate the efficacy and safety of covered, self-expanding, metallic stents (SEMSs) as a transition to silicone stent implantation for treating severe PTBS. METHODS: We retrospectively reviewed the data of patients with severe PTBS who received airway stenting in the First Affiliated Hospital of Guangdong Medical University between September 2015 and May 2019. The types of the stent, intervention procedures, bronchoscopic findings, clinical outcomes and related complications were collected and analyzed. RESULTS: Fifty-eight cases with severe PTBS were included in this study. Thirteen (22.4%) of the patients received bronchial silicone stent implantation immediately after dilations. For the remaining 45 (77.6%) patients, silicone stents could not be deployed after dilations and SEMSs implantation was implemented as a bridge to silicone stenting. The SEMSs were placed for an interval of 28.4 ± 11.1 days. All of the silicone stents were inserted successfully following the removal of SEMSs. No SEMS-related complication occurred. The subgroup analysis showed that patients who received transitional SEMSs had less luminal caliber but fewer transbronchial dilations before silicone stent implantation (p < 0.05). CONCLUSION: Covered SEMS placement as a transition to silicone stenting could serve as a feasible procedure to reduce complications and improve the success rate of silicone stent implantation in patients with severe PTBS.The reviews of this paper are available via the supplemental material section.

[Study on the extraction of breviscapine from Erigeron breviscapus with ultrasonic wave technology optimized by central composite design-response surface method].

OBJECTIVE: To evaluate the effectiveness of ultrasound-assisted extraction and establish the optimized extraction conditions of breviscapine from Erigeron breviscapus. METHODS: On the basis of the single factor and according to the central composite design principles (CCD), the response surface method (RSM) with 3 factors and 3 levels was adopted and the independent variables were ultrasonic wave extracting time, ethanol concentration, and the ratio of solvent volume to Erigeron breviscapus mass, breviscapine extraction yield determinated by HPLC was used as response value. RESULTS: Ultrasonic wave extracting time of 24.5 min, ethanol concentration of 74.7% and the ratio of solvent volume to Erigeron breviscapus mass of 19.8 (mL/g) were selected as optimum conditions. Regression coefficients of binomial fitting complex model was 0. 9549 and the predicted breviscapine extraction yield was 0.641%, while the actual extraction yield was 0.632% (n = 5), with relative error of -1.14%. CONCLUSION: This study confirms the efficiency of ultrasound-assisted extraction as a simple, inexpensive and effective method to improve the extraction of breviscapine from Erigeron breviscapus. The observed and predicted values are close to each other, which proves that the optimization of supersonic extraction process of breviscapine from Erigeron breviscapus by CCD-RSM is reasonable and successful.