<prompt> In Video assisted thoracoscooic surgery for better vision the space in the operative field is created by-Self retaining retractorCollapse of ipsilateral lungRib spacingCo2 insufflations  <response>: In contrast to most laparoscopic techniques, the working space for VATs is created not by adding an insuffalation gas but rather by removing air from the ipsilateral lung parenchyma causing collapse of the ipsilateral lung. Ref : Sabiston, 17e p465 