ABSTRACT
BACKGROUND:Foreign studies have found that the magnesium alloy stent is safe and effective, but there are few studies on the degradation performance of magnesium alloy stents in China.OBJECTIVE:To investigate the degradation of degradable AZ31 magnesium alloy stent in the rabbit abdominal aorta and the effect of degradation process on vascularization.METHODS:Twenty-eight rabbits were enrolled, and the degradable AZ31 magnesium alloy stent was implanted into the rabbit abdominal aorta. Postoperative abdominal aortic X-ray examination and histological observation were done at 30, 60, 90, 120 days after implantation.RESULTS AND CONCLUSION:(1) X-ray examination: 30 days after implantation, the stent expanded completely with structural integrity; 60 days after implantation, the stent deformation, partial stent fracture, and lose of support were found; 90 days after implantation, only a small amount of support rod residues were found, and the majority of the stent was degraded; and 120 days after implantation, there was no support rod residual, and the stent was degraded completely. (2) Histological observation: 60 days after implantation, the number of residual support rods was less than that 30 days after implantation (P< 0.05), the number value at 90 days after implantation was lower than that at 30 and 60 days after implantation (P< 0.05), and the number value at 120 days after implantation was lower than that at 30, 60, 90 days after implantation (P < 0.05), indicating that the number of residual support rods was negatively correlated with post-implantation days. The time for complete stent degradation was 124.8 days. The intimal area at 90 days after implantation was higher than that at 30, 60, 120 days after implantation (P < 0.05), while the lumen area was smaler than that at 30, 60, 120 days after implantation (P < 0.05). There was no significant difference in the intimal area and lumen area at latter three time points after implantation. To conclude, the degradation of the degradable AZ31 magnesium alloy stent in the rabbit abdominal aorta can be completed within 124.8 days, and at 90 days after the stent is implanted, vascular intimal hyperplasia and lumen stenosis are most serious, and then gradualy reduced.
ABSTRACT
Twelve ASA Ⅳ or Ⅴ patients with severe airway stenosis, aged 34-87 yr, weighing 50-80 kg,were enrolled in the study. The guidewire and endotracheal tube were inserted through the oral cavity under the guidance of the method of interventional radiology. The expandor was then exchanged and the endotracheal tube was placed in the suitable position within the trachea along the expandor under X-ray guidance. Endotracheal intubation was technically successful in all patients, without serious complications in the process. The intubation time was 1-5 min.
ABSTRACT
Objective To investigate the optimal window width and window level for measuring the airway dimensions with spiral CT scan in Japanese white big-ear rabbits so as to lay the foundation for airway stenting in animal experiments. Methods Multi-slice spiral CT scanning of cervico-thoracic region was performed in 30 healthy adult Japanese white big-ear rabbits, the anteroposterior and transversal diameter of the thoracic trachea, the anteroposterior diameter of the right and left bronchus were measured with lung window, mediastinum window and special fat window separately. The revealing rate of the tracheal wall and the measuring results in different windows and levels were recorded and compared with the anatomical data. The differences of the relevant data were statistically analyzed. Results With lung window, the tracheal wall was well demonstrated, but the relevant data were smaller than that with mediastinum window. With mediastinum window, the data were bigger and the tracheal wall border appeared blurred. The results obtained with fat window were close to the actual anatomical data. Conclusion For accurately measuring the anteroposterior and transversal diameter of the thoracic trachea in Japanese white big-ear rabbits with multi-slice spiral CT scan, fat window should be adopted, which is helpful for the preparation of tracheal and bronchial stents.
ABSTRACT
Objective To investigate the feasibility and therapeutic effect of stenting therapy by using modified Y-shaped self-expandable metal stent for the stenosis of gastroenteric stoma. Methods According to the particular anatomic structures and the pathological features of the narrowed gastroenteric stoma,the authors designed a modified Y-shaped self-expandable metal stent. Under the fluoroscopic guidance,implantation of modified Y-shaped self-expandable metal stent was performed in 5 patients with narrowed gastroenteric stoma. The technical safety and the clinical results were evaluated. Results The modified Y-shaped self-expandable metal stent was successfully implanted with one procedure in all five patients. After the implantation the symptoms such as nausea,vomiting,abdominal distension were promptly relieved,and the patients' living quality was markedly improved. Conclusion The stenting therapy with modified Y-shaped self-expandable metal stent can rapidly relieve the stenosis of gastroenteric stoma once for all. The technique is feasible and the short-term effect is reliable,therefore,it is worth popularizing this therapy in clinical practice.