Effects of unilateral lung volume reduction surgery with different resection volumes on pulmonary functions and alveolar morphology of emphysematous rabbits
- VernacularTitle:单侧肺减容术肺切除量对肺气肿模型兔肺功能和肺泡形态学的影响
- Author:
Qunyou TAN
;
Ruwen WANG
;
Yaoguang JIANG
;
Taiqian GONG
;
Dongliang LI
- Publication Type:Journal Article
- From:
Chinese Journal of Tissue Engineering Research
2005;9(23):251-253
- CountryChina
- Language:Chinese
-
Abstract:
BACKGROUND: Rehabilitation exercise and conservative treatment do not bring about good therapeutic effect for severe obstructive emphysema.And lung volume reduction surgery (LVRS) is an effective method for this kind of disease. How much emphysematous tissue should be resected in LVRS to achieve the best curative effect has been a concern.OBJECTIVE: To evaluate the pulmonary functional and alveolar morphologic changes in emphysematous rabbits after unilateral LVRS, and to compare the effects of different resection volumes.DESIGN: A completely randomized and controlled trial.SETTING: Thoracic Surgery Center of Daping Hospital of the Third Military Medical University of Chinese PLA.MATERIALS: This study was completed at the Laboratory of Thoracic Surgery Center of Daping Hospital of the Third Military Medical University of Chinese PLA from Frebruary 2003 to August 2003. Totally 50 New Zealand white male rabbits of cleaning grade were involved. These animals were divided randomly into groups of emphysema (A), less volume LVRS (B), middle volume LVRS (C), larger volume LVRS (D), and shame operation (E) .METHODS: Making of the rabbit emphysema model: Rabbits were put into an organic glass box and they inhaled passively smog produced from the cigarettes. Within seven weeks, 15 cigarettes (Yinxiang .Brand) were lighted for about 30 minutes every time, once per day and five times a week. Elastase for 3 mL(2000 U/kg) from porcine pancreas (SERVA Co.,Ltd) was injected into the rabbits' trachea in the fourth week. Intervention for different groups: Rabbits in Group A received no operation at all. Animals in other four groups were given general anesthesia by muscular injec tion of Sumianxin Ⅱ and they were then fixed supinely on the operation table. The rabbits were intubated with a 3-mm endotracheal tube and mechanically ventilated (HX-200 ventilator) with a tidal volume of 12 mL/kg and a respiratory rate of 40-50/minute. Thoracotomy was conducted through anterolateral incision of the fourth right intercostals area. The upper and lateral pulmonary tissues of the first lobe of the right lung were resected in Group B. For group C, the upper and lateral pulmonary tissues of the first and the second lobes of the lung were resected. For Group D, the upper and lateral pulmonary tissues of the first, second and the third lobes of the right lung were resected. The pulmonary removal was about a half of the total volume of the lobe. The specimens were removed, followed by 3-0 mattress suture of the wounds. Then, fibrin sealant was insufflated to avoid air leakage after the operation. Thoracotomies without any resection of lung parenchyma were carried out in Group E. Histologic inspection and quantitatively morphologic analysis of the left lung was postoperatively carried out eight weeks later.MAIN OUTCOME MEASURES: Quantitative analysis of pulmonary functions and alveolar morphology in rabbits with emphysema after lung volume reduction surgery with different resection volumes RESULTS: All the fifty rabbits were analyzed, and there were ten animals in each group. ① Comparison of ventilation volume in each group: In Group C, vital volume (VT), forced expiratory volume in 0.3 s (FEV0.3),FEV0.3/forced expiratory capacity (FVC) were all higher than those of Group A [(6.69±0.83) mL, (6.39±1.35) mL, (64.5±16.1)％; (5.76±0.84) mL,(5.23±1.37)mL, (50.2±15.6)％, P＜ 0.05], while functional residual capacity (FRC) was lower than that in group A [(14.3±1.9)mL; (19.3±3.1)mL, P＜ 0.05].Compared with Group A, no obvious difference in the above lung functions of Groups B, D and E was observed (P ＞0.05). ② Histopathological observation results: In group C, obvious repairs to dilatation and destruction of alveolar ducts or cyst were observed and the aggregation of macrophage and neutrophils in the end-terminal bronchiole decreased. In Group D, the inflammatory cells decreased, but alveolar destruction and dilatation became more marked. ③Comparison of the total lung capacity (TLC): TLC of Group C was less than that of group A [(42.1 ±5.8)mL, (58.5±7.6)mL, P＜ 0.05].Compared with group A, no obvious difference in the above lung functions of Groups B, D and E was observed (P ＞0.05). ④ Quantitative analysis result of alveolar morphology: The number of alveoli (Na) and density of alveolar septum (Ds) in Group C were much larger than those of group A [(17.6±3.1)/field, (18.6±2.1)％; (11.3±2.7)/field, (15.2±3.6)％, P＜ 0.05] while the diameter of the alveoli (Da) in Group C was significantly lower than those of Group A[(78.1±7.1),(93.4±10.2)μm, P ＜ 0.05].CONCLUSION: Combination of smog and elastase successfully induced rabbit model of obstructive emphysema. Unilateral LVRS could improve emphysematous rabbits' pulmonary functions. Improved in pulmonary functions was not obvious by LVRS with less (12.5％) or larger (37.5％) resection volume of lung parenchyma. LVRS with appropriate resection volume (25％) could effectively eliminate airway inflammation, alleviate alveolar dilatation and destruction of the residual lung parenchyma, and thus improve pulmonary ventilation function.
