title: Impact of conversion on surgical outcomes after laparoscopic operation for rectal carcinoma: a retrospective study of 1,073 patients.
abstract: BACKGROUND
  In laparoscopic operations for rectal carcinoma, only a few multicenter studies of a large number of patients have examined the impact of conversion on outcomes and determined risk factors for conversion. This study was designed to evaluate short-term outcomes and risk factors for conversion to open operation in laparoscopic operations for rectal carcinoma.
  
  
  METHODS
  A total of 1,073 patients with carcinoma of the rectum and anus who underwent laparoscopic operations were reviewed retrospectively. Patients were collected from 28 institutions. Patients who required conversion during laparoscopic operation were compared with those with completed laparoscopic resection.
  
  
  RESULTS
  Conversion rate was 7.3% (n = 78), and patients requiring conversion were considerably heavier (mean body mass index 24.6 versus 22.7) and had a substantially higher rate of low anterior resection (94.9% versus 83.5%). Conversion was also associated with longer operation time (median 295 minutes versus 270 minutes), greater blood loss (median 265 mL versus 80 mL), longer median postoperative hospital stay (20 days versus 14 days), and higher rates of intraoperative (32.1% versus 3.5%) and postoperative (43.6% versus 21.1%) complications. In multivariate analysis, body mass index and rate of low anterior resection were predictive of conversion.
  
  
  CONCLUSIONS
  Conversion to open operation is associated with greater morbidity than completed laparoscopic resection. Body mass index and the particular laparoscopic procedure are risk factors for conversion, indicating that appropriate patient selection is essential in laparoscopic operations for rectal carcinoma.
authors.affiliation: Division of Colorectal Surgery, National Cancer Center Hospital, Tokyo, Japan. seyamamo@ncc.go.jp
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Masaki
authors.initials: M
authors.lastname: Fukunaga
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Miyajima
authors.forename: Junji
authors.initials: J
authors.lastname: Okuda
authors.forename: Fumio
authors.initials: F
authors.lastname: Konishi
authors.forename: Masahiko
authors.initials: M
authors.lastname: Watanabe