title: Trainee competence in thoracoscopic esophagectomy in the prone position: evaluation using cumulative sum techniques.
abstract: OBJECTIVE
  Minimally invasive esophagectomy (MIE) has less morbidity than the open approach. In particular, thoracoscopic esophagectomy in the prone position (TEP) has been performed worldwide. Using the cumulative sum control chart (CUSUM) method, this study aimed to confirm whether a trainee surgeon who learned established standards would become skilled in TEP with a shorter learning curve than that of the mentoring surgeon.
  
  
  METHODS
  Surgeon A performed TEP in 100 patients; the first 22 patients comprised period 1. His learning curve, defined based on the operation time (OT) of the thoracic procedure, was evaluated using the CUSUM method, and short-term outcomes were assessed. Another 22 patients underwent TEP performed by surgeon B, with outcomes compared to those of surgeon A's period 1.
  
  
  RESULTS
  Using the CUSUM chart, the peak point of the thoracic procedure OT occurred at the 44th case in surgeon A's experience of 100 cases. With surgeon A's first 22 cases (period 1), the peak point of the thoracic procedure OT could not be confirmed and graph is expanding soaring at CUSUM chart. The CUSUM chart of surgeon B's experience of 22 cases clearly indicated that the peak point of the thoracic procedure OT occurred at the 17th case. The rate of recurrent laryngeal nerve palsy for surgeon B (9 %) was significantly lower than for surgeon A in period 1 (36 %) (p = 0.0266).
  
  
  CONCLUSIONS
  There is some possibility for a trainee surgeon to attain the required basic skills to perform TEP in a relatively short period of time using a standardized procedure developed by a mentoring surgeon. The CUSUM method should be useful in evaluating trainee competence during an initial series of procedures, by assessing the learning curve defined by OT.
authors.affiliation: Department of Gastroenterological Surgery, Hyogo Cancer Center, 13-70, kitaoji-cho, Akashi, Hyogo, 673-8558, Japan. oshikiri@med.kobe-u.ac.jp.|Division of Gastrointestinal Surgery, Department of Surgery, Graduate School of Medicine, Kobe University, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017, Japan. oshikiri@med.kobe-u.ac.jp.
authors.forename: Taro
authors.initials: T
authors.lastname: Oshikiri
authors.affiliation: Department of Gastroenterological Surgery, Hyogo Cancer Center, 13-70, kitaoji-cho, Akashi, Hyogo, 673-8558, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yasuda
authors.affiliation: Division of Gastrointestinal Surgery, Department of Surgery, Graduate School of Medicine, Kobe University, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Yamamoto
authors.affiliation: Division of Gastrointestinal Surgery, Department of Surgery, Graduate School of Medicine, Kobe University, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Kanaji
authors.affiliation: Division of Gastrointestinal Surgery, Department of Surgery, Graduate School of Medicine, Kobe University, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017, Japan.
authors.forename: Kimihiro
authors.initials: K
authors.lastname: Yamashita
authors.affiliation: Division of Gastrointestinal Surgery, Department of Surgery, Graduate School of Medicine, Kobe University, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017, Japan.
authors.forename: Takeru
authors.initials: T
authors.lastname: Matsuda
authors.affiliation: Division of Gastrointestinal Surgery, Department of Surgery, Graduate School of Medicine, Kobe University, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Sumi
authors.affiliation: Division of Gastrointestinal Surgery, Department of Surgery, Graduate School of Medicine, Kobe University, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017, Japan.
authors.forename: Tetsu
authors.initials: T
authors.lastname: Nakamura
authors.affiliation: Department of Gastroenterological Surgery, Hyogo Cancer Center, 13-70, kitaoji-cho, Akashi, Hyogo, 673-8558, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Fujino
authors.affiliation: Department of Gastroenterological Surgery, Hyogo Cancer Center, 13-70, kitaoji-cho, Akashi, Hyogo, 673-8558, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Tominaga
authors.affiliation: Division of Gastrointestinal Surgery, Department of Surgery, Graduate School of Medicine, Kobe University, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Suzuki
authors.affiliation: Division of Gastrointestinal Surgery, Department of Surgery, Graduate School of Medicine, Kobe University, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kakeji
mesh_terms: D000368:Aged; D002983:Clinical Competence; D004938:Esophageal Neoplasms / Q000601:surgery*; D016629:Esophagectomy / Q000193:education*; D005260:Female; D006801:Humans; D059032:Learning Curve; D008297:Male; D008875:Middle Aged; D061646:Operative Time; D056888:Patient Positioning; D016684:Prone Position; D013906:Thoracoscopy / Q000193:education*
keywords: Cumulative sum techniques; Esophageal surgery; Minimally invasive esophagectomy; Prone position; Trainee competence