Carbon nanoparticle-assisted natural orifice specimen extraction surgery with left colic artery preservation: a retrospective study - Mengao Qian; Shangyu Yin; Kepeng Hu; Quanpeng Wang; Weilan Cao; Changbao Liu; Zhonglin Wang; Chongjie Huang (Videosurgery and Other Miniinvasive Techniques, 2022)