Endoscopic approaches for treating emphysema

Surgical treatment of severe pulmonary emphysema has so far been associated with relatively high perioperative morbidity and mortality. In the past two decades, novel approaches to lung volume reduction and alternative minimally invasive endoscopic techniques have been developed. This review presents the different techniques (blocking and nonblocking) available until present as well as the appropriate patient selection and possible complications. Areas covered: All available randomized controlled trials (RCTs) have been evaluated. The only blocking technique is the reversible valve implantation. It results in lobar volume reduction and clinical benefit in emphysema patients with absent interlobar collateral ventilation and its efficacy has been confirmed in various RCTs. Non-blocking techniques that are independent of collateral ventilation include the partially irreversible coil implantation leading to parenchymal compression, the irreversible bronchoscopic thermal vapor ablation, and the polymeric lung volume reduction both inducing inflammatory reaction. These methods have been up to date examined in a few RCTs only. Finally, the targeted lung denervation aims at sustainable bronchodilation by ablation of parasympathetic pulmonary nerves. Expert commentary: Future studies must address the predictors of clinical outcome as well as the reduction of complications to improve both outcome and safety.