BackgroundWe studied the safety, effectiveness, and limitations of airway stenting using self-expanding metal stent (SEMS) in patients with malignant central airway obstruction (CAO).MethodsA retrospective review of records of patients undergoing SEMS placement for malignant CAO during year 2013 - 2014 was done.ResultsSixteen patients (11 males and five females) underwent SEMS placement for malignant CAO. Median (range) age was 66 (54 - 78) years. No perioperative or immediate postoperative complications were seen except acute myocardial infarction (AMI) in one patient. Three patients were transferred to intensive care unit (ICU) for closer monitoring after the procedure and were discharged the next day. All four patients with lung atelectasis on presentation experienced complete re-expansion of the lung post-stenting. The dyspnea was substantially relieved in 14 (87.5%) patients. Two of the three patients who had been intubated were weaned off from the ventilator following stent insertion. Stent patency was maintained until death in all patients except one. Median survival from the date of diagnosis and the date of stent placement in lung cancer, esophageal cancer, and thyroid cancer were 140 (21 - 564) and 85 (15 - 361), 288 (80 - 419) and 61 (60 - 171), and 129 (71 - 187) and 67 (16 - 118) days, respectively. This survival was similar to reported expected survival associated with the underlying malignancy. During follow-up, granulation tissue (n = 1), mucostasis (n = 1), and tumor ingrowth (n = 2) were the most frequently encountered complications.ConclusionSEMSs are safe and effective in reversing respiratory failure caused by malignant CAO, averting premature death, allowing application of cancer targeted therapy, and restoring impending shortened survival to expected life expectancy associated with the underlying malignancy.

Nanocrystals hydroxyapatite (nHA) was synthesized and modified chemically, and nanocrystals hydroxyapatite / poly(L-lactide)/poly(ethylene succinate)(nHA/PLLA/PES) composite was prepared by melt-blending using nHA, PLLA and PES as reactants in a stainless steel chamber. The obtained nHA was of high purity and high crystallinity as well, its mean sizes measured from TEM observations were 65±35nm (long axis) and 40±10nm (short axis), and are close to the endosteal needle hydroxyapatite crystals size ((15 ~ 20) nm×60 nm) in the human body. The mechanical properties of nHA/ PLLA/PES blends were determined by bending and tensile tests and the effects of nHA content on the mechanical properties of nHA/PLLA/PES blends were investigated. The blending modulus and tensile modulus increase with the nHA (0,5,10,15and 20 wt.%) content increase, while blending strength increases up to HA mass fraction of 10% and after that decreases. SEM images revealed that the surface changed from rough to smooth with increasing nHA content, especially with nHA content higher than 20%, which implied the failure mechanism of the material changes from ductile to brittle.