The purpose of this study is to compare the efficacy of three bronchial blockers, namely an Arndt® wire-guided endobronchial blocker, a Cohen Flexi-tip endobronchial blocker (Cook Critical Care, Bloomington, IN) or a Fuji Uni-blocker (Fuji Systems, Tokyo, Japan), for achieving selective lobar collapse. It is generally accepted that bronchial blockers perform better clinically when positioned in the longer left mainstem bronchus versus the shorter right bronchus.9 However, this could not be extended for the SLB. Thus, the present study will include both sides thoracic procedures and studied patients will be stratified to the side on which their surgery will be performed, right or left.