In a large study a decade ago, called the National Emphysema Treatment Trial(NETT), the surgery didn't show an overall survival advantage over medical management. 10年前进行的一项名为全国肺气肿治疗试验(NationalEmphysemaTreatmentTrial)的大型研究显示,与药物治疗相比,手术并未显现出会给病患在总体上带来更高的存活率。