Interventional bronchoscopic treatment of lung cancer

Interventional bronchoscopy has developed rapidly in the management of lung cancer. Besides ablativeresection of various modalities and balloon dilation/stent placement, which have been widely used in themanagement of malignant central airway obstruction, bronchoscopic brachytherapy and transbronchoscopic local injection of drugs are also developing. For early-stage peripheral lung cancer,transbronchoscopic ablation and the assisted localization of preoperative peripheral lung nodules bybronchoscopy are the new techniques. In addition, interventional bronchoscopy can manage complications related to lung cancer. Overall, interventional bronchoscopy has been an indispensable componentin the treatment of lung cancer and has vast space for development. The review summarizes the recentupdates.

Effect of three interventional bronchoscopic methods on tracheal stenosis and the formation of granulation tissues in dogs

Background Therapeutic approaches for tracheal stenosis caused by the formation of exuberant granulation tissues usually include electrocautery, mechanical dilation, laser therapy, argon plasma coagulation （APC）, cryotherapy and stent placement. However, restenosis after stent insertion remains a significant limitation. We examined the efficacy of three different approaches, including induction of mechanical lesions, APC performed with different powers or durations and cryotherapy, to identify the method that limited the formation of granulation tissue. Methods Twelve specially bred research mongrel dogs were divided into three groups. In group 1 （four dogs） mild （procedure 1; two dogs） or moderate （procedure 2; two dogs） damage was induced mechanically. Group 2 （six dogs） received APC at different powers or durations （procedure 3：30 W, 1 cm/s; procedure 4：30 W, 2 cm/s; procedure 5：25 W, 3 cm/s）. Group 3 （two dogs） received cryotherapy （procedure 6： two freeze-thaw cycles of 30 seconds）. Uncovered self-expandable metallic stents were inserted in all dogs to maintain a continuous stimulus to the trachea mucosa. Dogs were monitored for 4 weeks and the relationship between granulation tissue proliferation and method used was analyzed. Results In group 1, granulation tissue growth increased with more severe mechanical damage. The growth of granulation tissue in group 2 was more pronounced than in group 1, and both dogs in procedure 3 died because of severe stenosis. In this group, the formation of granulation tissue decreased with decreasing power and duration. In group 3, no obvious granulation tissue was found at week 4. Conclusions Lesions and stimuli from a foreign body （the stent） are two important factors that lead to overgrowth of granulation tissue. Thermal lesions, such as APC, seem to induce greater granulation tissue growth and cartilage damage compared with mechanical and cryotherapy lesions. Cryotherapy in combination with mechanical dilation may be a safe and effective treatment method for managing tracheal stenosis caused by the formation of granulation tissue.