Closed trans-intersphincteric fistulotomy: a new modified sphincter-sparing technique for high transsphincteric anal fistula - Chen, Bo; Wang, Yueting; Mei, Zubing; Mao, Chang; Liu, Yicheng; Zhao, Wenjun; Li, Yingying; Ye, Qianqian; Xu, Jin; Wang, Qingming (Frontiers in Surgery, 2024)