肺减容术对肺气肿兔膈肌生物力学的影响

目的　探讨肺减容术对肺气肿兔膈肌生物力学特性的影响。方法　新西兰大白兔 40只 ,10只为正常对照组 ,3 0只熏香烟加气管内滴入弹性蛋白酶方法制备肺气肿模型 ,10只行双肺减容术 (肺减容组 ) ,10只仅做正中切口开胸(假手术组 ) ,10只为肺气肿未做手术 (肺气肿未手术组 )。饲养 16周全部活杀取膈肌条测定其抗拉强度、屈服强度、断裂伸长率等生物力学特性。结果　与正常对照组相比 ,肺气肿未手术组和假手术组膈肌条的抗拉强度 ,屈服强度 ,断裂伸长率较正常对照组显著降低 (P <0 0 5 ) ,而肺减容组较对照组无显著差异 (P >0 0 5 ) ,较肺气肿未手术组和假手术组显著升高 (P <0 0 5 )。结论　肺减容术是治疗慢性阻塞性肺气肿的有效方法 ,它除可能通过恢复肺的弹性回缩外还能通过恢复肺气肿膈肌生物力学特性而改善肺功能。

Effects of lung volume reduction surgery on diaphragmatic biomechanics in emphysematous rabbits

Objective To investigate the effects of lung volume reduction surgery (LVRS) on the diaphragmatic biomechanics in emphysematous rabbits. Methods A total of 40 New Zealand White rabbits were divided into four groups (n=10 in each group). Other 30 rabbits were induced into pulmonary emphysema with smok and elastase. The other 10 served as the normal controls. In the LVRS group, bilateral lung volume reduction was performed in 10 emphysematous rabbits. In the sham operation group, sternotomy was performed in 12 emphysematous rabbits. Twelve emphysematous rabbits in the emphysema group were treated non-operatively. Parameters of diaphragmatic biomechanics were measured at 16 weeks after operation. Results Tensile strength, the yield strength, and elongation at the rupture of diaphragm were decreased significantly in the emphysema and sham operation group as compared with those in the normal control group (P<0.05), but those parameters at the rupture of diaphragm in the LVRS group were similar to those in the normal control group and significantly increased as compared with those of the emphysema and sham operation group (P<0.05). Conclusion LVRS, an effective method to treat pulmonary emphysema, can improve the lung function by recovering both pulmonary elastic recoil and the mechanical characteristics of the diaphragm.