金属硅膜支气管封堵器置入犬支气管的封堵效果及安全性研究

Development of silicon covered metallic bronchial occlusive device and its efficacy and safety for bronchial closure in dogs

目的评价研制的金属硅膜支气管封堵器的有效性和安全性。方法取健康杂种犬18条,按随机数字表法分为3组(n=6),分别经支气管镜置入以镍钛合金丝编织成哑铃状、普通螺栓状、致密螺栓状3种支气管封堵器,一端覆硅胶膜,且每只犬置入相同的封堵器2枚。观察实验动物的耐受性,定期复查血象、支气管镜、胸部CT扫描,8周后观察封堵器附近支气管组织及远端肺组织变化。结果预设的18条犬36只支气管封堵器全部经支气管镜成功置入。观察期内,除1例因误吞哑铃状封堵器致消化道梗阻而死亡外,其余犬耐受性良好;截至封堵第8周,36只封堵器中,脱落共有11只(11/36),其中哑铃状封堵器脱落9只(9/12),普通螺栓状封堵器脱落2只(2/12),致密螺栓状封堵器无脱落(0/12)。胸部CT扫描和组织病理学检查证实,部分封堵的肺叶有萎陷,肺组织表面有瘢痕形成,封堵部位远端肺泡腔缩小,肺间质内有淋巴和单核细胞浸润,并伴有纤维组织增生;2例封堵部位及其周围有轻度阻塞性炎症改变,未出现肺脓肿及坏死。尸检取出的封堵器表面光整,弹性度良好,无变形、扭曲及断裂,所覆的硅胶膜无渗漏破损。结论试制的镍钛合金覆硅胶膜支气管封堵器置入方便,组织相容性好,动物耐受性较好。3种不同的支气管封堵器中,以致密螺栓状封堵器的稳定性最好,有望用于支气管封堵治疗。

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 pertormed 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.