Objective To assess the efficacy and safety of trial-produced bronchial occlusive device made of silicon covered metal for bronchial closure in dogs.  Methods Eighteen healthy mongrel dogs were divided into 3 groups (n=6 for each group). Dumbbell-like

ordinary screw-like and compact screw-like bronchial occlusive devices made of silicon covered nickel-titanium alloy

were respectively implanted into the target bronchi by bronchoscope. Each dog was inserted two occlusive devices of the same shape. Then the tolerance of dogs and their hemogram were observed

and bronchoscopy and computer tomography scan of chest were performed regularly. Eight weeks later

the changes of bronchial and lung tissues adjacent to occlusive devices were observed.  Results Procedure of operation was simple and successful. During the observation

except for one dog died from swallowing a dumbbell-like device

the others were well-tolerable. At 8 weeks after operation

11 pieces of occlusive device (11/36) shed

including 9 dumbbell-like (9/12) and 2 ordinary screwlike devices (2/12). The computer tomography scan and histopathologic examination showed that some of the lung tissues had collapsed

pulmonary alveolus distal to occlusive device collapsed obviously

the lung interstitial was infiltrated by lymphocytes and monocytes

and the hyperplasia of fibrous tissues developed. Obstructive pneumonia developed in 2 cases

but no lung abscess or tissue necrosis. No obvious deformation

twist or rupture of occlusive devices was found

and the membrane of silicon were not damaged 8 weeks after operation.  Conclusion The bronchial occlusive devices made of silicon covered nickel-titanium alloy can be implanted into the target  bronchi by bronchoscope conveniently

with good tissue compatibility. The compact screw-like bronchial occlusive device has the best stability and is expected for the treatment of bronchial occlusion.