[en] Objective: To evaluate the preliminaily clinical efficacy and retrievability of a retrievable hinged covered metallic stent in the treatment of the bronchial stump fistula (BSF). Methods: Between April 2003 and March 2005, 8 patients with bronchial stump fistula after pneumonectomy or lobectomy were treated with two types (A and B) of retrievable hinged covered metallic stents. Type A stent was placed in 6 patients and type B in 2 under fluoroscopic guidance. The stent was removed with a retrieval set when BSF was healed or complications occurred. Results: Stent placement in the bronchial tree was technically successful in all patients, without procedure-related complications. Immediate closure of the BSF was achieved in all patients after the procedure. Stents were removed from all patients but one. Removal of the stents was difficult in two patients due to tissue hyperplasia. Patients were followed up for 6-21 months. Placement of the stents remained stable in all patients except one due to severe cough. Permanent closure of BSF was achieved in 7 (87.5%) of 8 patients. Conclusion: Use of a retrievable hinged covered expandable metallic stent is a simple, safe, and effective procedure for closure of the BSF. Retrieval of the stent seems to be feasible. (authors)

[en] Objective: To compare the sensitivity between forceps biopsy and brushing, and to explore a feasible approach to pathological diagnosis of the obstructive jaundice. Methods: 92 consecutive patients with obstructive jaundice underwent transluminal forceps biopsy and brushing during percutaneous transhepatic cholangiography and percutaneous transhepatic cholangiodrainage. The technique was performed through a preexisting percutaneous transhepatic tract with multiple specimens obtained after passing the forceps biopsy or brush into a 8-French sheath. Finally the specimens were fixed with formalin for pathologic or cytologic diagnosis. Results: The histopathologic diagnosis was acquired in 81 out of 92 patients with forceps biopsy reaching the successful rate of 97.83%. Sensitivity of forceps biopsy in 92 patients was higher than that of brush in 84 patients (88.04% vs 76.19% χ²=4.251, P= <0.05). Conclusions: Percutaneous transhepatic cholangiobiopsy is a simple technique with minimal invasion, high sensitivity and worthy to be used spread extensively. Percutaneous transluminal brush cytology is also an useful method for establishing a diagnosis of cholangiocarcinoma. (authors)

[en] Two-dimensional (2-D) geometry effect on space-charge-limited (SCL) current of an axially symmetrical planar diode was studied with 2.5 D particle-in-cell (PIC) simulation. A volume-weighting cloud-in-cell model was used to improve the accuracy of the PIC method in z-r coordinates system. The simulations with various emitter radii were carried out on the same diode with the applied voltages being 100 kV and 1 MV respectively. The simulation results show that the 2D geometry effect on SCL current monotonically diminishes with the dimensionless ratio of emitter radius to gap separation, whether in relativistic or non-relativistic regime. When the ratio is more than 0.5, the first-order analytical theory well predicts the limiting current. But when the ratio is no more than 0.5, the second-order correction must be considered. (authors)

[en] A new type of AC PDP (alternating current plasma display panel) cell with a five-electrode structure is developed to improve the luminous efficiency of AC PDP. The discharge efficiency of this new cell structure is investigated by a 2D fluid simulation. Continuity equations and flux density equations for charged particles and excited atoms, energy balance equation for electrons are included in the model. The discharge gas is He + 5%Xe. The reactions of ionization, excitation, recombination, and radiation are taken into account. The vacuum ultraviolet radiation efficiency of the five-electrode cell structure is about 20% higher than that of a conventional three-electrode cell structure. (author)

[en] Objective: To develop a modified focal thromboembolic stroke model of rat suitable for the delayed thrombolytic therapy. Methods: Ten fibrin-rich autologous blood clots (0.8-1.0 mm in length, 0.35 mm in width) were injected into the internal carotid artery to establish a focal thromboembolic stroke model. 138 embolized rats were divided randomly into ischemic group (n=68) and delayed thrombolytic therapeutic group (n=70). At 3 h, 6 h and 9 h after embolization, the rats in delayed thrombolytic therapeutic group were treated with 10 mg/kg recombinant tissue plasminogen activator respectively, while no treatment was performed on ischemic group. Lesion size, location, relative cerebral blood flow volume at different time, and intracranial hemorrhage after treatment were evaluated by MRI. After the last MRI examination, the rats were decapitated and their brain tissue were fixed with formalin for further pathology study. Results: Embolization with a preformed clot resulted in a focal infarction in the territory supplied by the MCA branch or anterior choroid artery, including 79.4% (104/131) of infarction located in ipsilateral parietal cortex or /and audoputamen, with infarction volume of (23.12 ± 6.04)% in embolized hemisphere. At 3 h, 6 h, and 9 h after embolization, the relative cerebral blood flow volumes were (36.86 ± 16.02)%, (40.67 ± 25.91)% and (44.72 ± 26.51)% respectively, with no statistical difference between them (3 h vs 6 h, Z=- 0.958, P=0.338, 3 h vs 9 h, Z=- 1.147, P=0.251). Hemorrhage was observed in 12 rats, all of that were in delayed thrombolytic therapeutic group. 13 rats died within 24 hours and 3 died within 12 days after delayed thrombolytic therapy. Conclusion: The modified rat thromboembolic brain model is reliable and repeaducible closely mimicking that of the human middle cerebral arterial branch thrombosis, suitable for investigating the delayed thrombolytic therapy in rats. (authors)

[en] Objective: To explore the technical feasibility and sensitivity of percutaneous transhepatic cholangiobiopsy in malignant obstructive jaundice, together with the guidance for clinical managements. Methods: 31 patients with obstructive jaundice after percutaneous transhepatic cholangiography and drainage were undergone percutaneous transhepatic cholangiobiopsy. The technique was performed through an preexisted percutaneous transhepatic tract with a 8-Frerch sheath, multiple specimens were obtained after passing the forceps for the biopsy. The specimens were fixed with formalin, and then taken for histopathologic diagnosis. Results: The histopathologic diagnosis was acquired in 30 of 31 patients (sensitivity, 96.8%). Conclusions: Percutaneous transhepatic cholangiobiopsy is an accurate, safety and reliable way, easy to perform with a histopathologic diagnosis sensitivity rate of 96.8%

[en] Objective: To design the trachea-main bronchus covered embranchment stent and study the primary treatment for thoracostomach main bronchial fistula and main bronchial stenosis. Methods: The stent was designed on the bases of the peculiar anatomic structure and the pathological changes of thoracostomach-main bronchial fistula and main bronchial stenosis. Under the fluoroscopic guidance, implantations were carried out in thoracostomach-carina fistula 1 case thoracostomach-left main bronchial fistula 1, thoracostomach-right main bronchial fistula and left main bronchial stenosis 1 case, altogether with 5 stents. Results: Stents were placed successfully, not only improving the breathing and living quality but also completing the closure of the ora of the thoracostomach-airway fistula with further vanishing of the choke after drinking and eating together with the inhalation pneumonia. The bronchus became normal in a main bronchial stenosis after the stent was taken out. Conclusions: Trachea-main bronchial covered embranchment stent could be used to close thoracostomach-airway fistula and to treat main bronchial benign/malignant stenosis. The procedure is simple and safe. (authors)

[en] Objective: To investigate the value of treating mediastinoesophageal fistula with covered stent through nasal esophagus drainage tube. Methods: Ten patients with mediastinoesophageal fistula were treated by 5F catheter inserting into the abscess cavities through nasal esophageal fistula, with stent placement in the esophagus. The abscess cavities were washed and angiograghied through drainage tube and the sites of the drainage tube were adjusted in time until withdrawal of the tube. Results: The drainage tubes were pulled out within 10-25 days with disappearance of the abscess cavities and normal diet intake without difficulty. Conclusions: Treating mediastinoesophageal fistula with covered stent through nasal esophagus drainage tube is safe, microinvasive economic and acceptable, worth to be recommended. (authors)

[en] Objective: To explore the interventional method to treat biliary recurrent jaundice after T tube drainage in patients with malignant obstructive jaundice due to cholangiocarcinoma. Methods: 7 biliary metallic stents were placed in 7 patients with recurrent jaundice after T-tube drainage in cholangiocarcinoma cases. Results: Stent placement was once successful in all 7 cases with successful rate of 100%. For all cases, TBIL, ALT, GTP and AKP values 7 days postoperatively were significantly lower than that of preoperation together with subsidence of jaundice satisfactorily for 100% after the treatment. Conclusions: Percutaneous placement of biliary metallic stents was effective economic, minimal invasive and safe for palliation of biliary recurrent jaundice after T tube drainage in cholangiocarcinoma-induced obstructive jaundice

[en] Objective: To explore the interventional methods to treat recurrent jaundice after palliative bilio-intestinal anastomosis in patients with malignant obstructive jaundice due to cholangiocarcinoma. Methods: Ten patients with recurrent jaundice after bilio-intestinal anastomosis were retrospectively evaluated. Nine of ten underwent PTCD with metallic stent placement, one underwent the inner-outer draining catheter procedure. The patients were evaluated with comparison in regard to preoperative conditions, TBIL, ALT, GTP and AKP values. Results: Stent placement was successful only once in all 10 cases with successful rate of 100%. TBIL, ALT, GTP and AKP values were significantly lower 7 days postoperative than that preoperation. Subsidence of jaundice was satisfactory for 100% in all patients after the treatment. Conclusions: Percutaneous placement of biliary metallic stents is a safety, simple, low complication method for managing recurrent jaundice after palliative bilio-intestinal anastomosis for the terminal stage of malignant obstructive jaundice