title: Robot-assisted intersphincteric resection facilitates an efficient sphincter-saving in patients with low rectal cancer.
abstract: OBJECTIVE
  Few investigations of robot-assisted intersphincteric resection (ISR) are presently available to support this procedure as a safe and efficient procedure. We aimed to evaluate the utility of robot-assisted ISR by comparison between ISR and abdominoperineal resection (APR) using both robot-assisted and open approaches.
  
  
  METHODS
  The 558 patients with lower rectal cancer (LRC) who underwent curative operation was enrolled between July 2010 and June 2015 to perform either by robot-assisted (ISR vs. APR = 310 vs. 34) or open approaches (144 vs. 70). Perioperative and functional outcomes including urogenital and anorectal dysfunctions were measured. Recurrence and survival were examined in 216 patients in which >3 years had elapsed after the operation.
  
  
  RESULTS
  The robot-assisted approach was the most significant parameter to determine ISR achievement among potent parameters (OR = 3.467, 95% CI = 2.095-5.738, p < 0.001). Early surgical complications occurred more frequently in the open ISR group (16 vs. 7.7%, p = 0.01). The voiding and male sexual dysfunctions were significantly more frequent in the open ISR (p < 0.05). The fecal incontinence and lifestyle alteration score was greater in the open ISR than in the robot-assisted ISR at 12 and 24 months, respectively (p < 0.05). However, the 3-year cumulative rates of local recurrence and survival did not differ between the two groups.
  
  
  CONCLUSIONS
  The current procedure of robot-assisted ISR replaced a significant portion of APR to achieve successful SSO via mostly transabdominal approach and double-stapled anastomosis. The robot-assisted ISR with minimal invasiveness might be a help to reduce anorectal and urogenital dysfunctions.
authors.affiliation: Department of Surgery, College of Medicine and Institute of Innovative Cancer Research, Asan Medical Center, University of Ulsan, 88, Olympic-ro-43-gil, Songpa-gu, Seoul, 05505, South Korea. jckim@amc.seoul.kr.
authors.forename: Jin Cheon
authors.initials: JC
authors.lastname: Kim
authors.affiliation: Department of Surgery, College of Medicine and Institute of Innovative Cancer Research, Asan Medical Center, University of Ulsan, 88, Olympic-ro-43-gil, Songpa-gu, Seoul, 05505, South Korea.
authors.forename: Jong Lyul
authors.initials: JL
authors.lastname: Lee
authors.affiliation: Department of Surgery, College of Medicine and Institute of Innovative Cancer Research, Asan Medical Center, University of Ulsan, 88, Olympic-ro-43-gil, Songpa-gu, Seoul, 05505, South Korea.
authors.forename: Abdulrahman Muaod
authors.initials: AM
authors.lastname: Alotaibi
authors.affiliation: Department of Surgery, College of Medicine and Institute of Innovative Cancer Research, Asan Medical Center, University of Ulsan, 88, Olympic-ro-43-gil, Songpa-gu, Seoul, 05505, South Korea.
authors.forename: Yong Sik
authors.initials: YS
authors.lastname: Yoon
authors.affiliation: Department of Surgery, College of Medicine and Institute of Innovative Cancer Research, Asan Medical Center, University of Ulsan, 88, Olympic-ro-43-gil, Songpa-gu, Seoul, 05505, South Korea.
authors.forename: Chan Wook
authors.initials: CW
authors.lastname: Kim
authors.affiliation: Department of Surgery, College of Medicine and Institute of Innovative Cancer Research, Asan Medical Center, University of Ulsan, 88, Olympic-ro-43-gil, Songpa-gu, Seoul, 05505, South Korea.
authors.forename: In Ja
authors.initials: IJ
authors.lastname: Park
mesh_terms: D001003:Anal Canal / Q000473:pathology / Q000601:surgery*; D005242:Fecal Incontinence / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D059351:Organ Sparing Treatments; D011182:Postoperative Care; D012004:Rectal Neoplasms / Q000473:pathology / Q000601:surgery*; D012371:Robotics / Q000379:methods*; D016019:Survival Analysis; D016896:Treatment Outcome
keywords: Abdominoperineal resection; Intersphincteric resection; Open; Rectal cancer; Robot