title: Optimal port placement planning method for laparoscopic gastrectomy.
abstract: OBJECTIVE
  In laparoscopic gastrectomy, as well as other laparoscopic surgery, the surgeon operates on target organs using a laparoscope and forceps inserted into the abdominal cavity through ports placed in the abdominal wall. Therefore, port placement is of vital significance in laparoscopic surgery. In this paper, we present a method for achieving optimal port placement in laparoscopic gastrectomy based on relationships between the locations of the ports and anatomical structures.
  
  
  METHODS
  We utilize three angle conditions to determine the optimal port placement. Proper angles for the angle conditions are calculated from measurements obtained during laparoscopic gastrectomy. The port positions determined by surgeons experienced in laparoscopic gastrectomy are measured using a three-dimensional positional tracker. The locations of the blood vessels, as well as other vital anatomical structures that are also critical in laparoscopic gastrectomy, are identified from computed tomography images. The angle relationships between the port and blood vessel locations are analyzed using the obtained positional information. Optimal port placement is determined based on the angle conditions.
  
  
  RESULTS
  We evaluated the proposed method using the positional information obtained during 26 laparoscopic gastrectomies. Our evaluation determined that the proposed method generates optimal port placement with average errors of 22.2 and 21.2 mm in the left- and the right-hand side ports for a lead surgeon. Experienced surgeons confirmed that the optimal port placement generated by the proposed method was sufficient for clinical use.
  
  
  CONCLUSIONS
  The proposed method provides optimal port placement in laparoscopic gastrectomy and enables a novice surgeon to determine port placement much like an experienced surgeon.
authors.affiliation: Information & Communications, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan. yhayashi@mori.m.is.nagoya-u.ac.jp.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Hayashi
authors.affiliation: Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya, 464-8681, Japan.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Misawa
authors.affiliation: Information & Communications, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan.
authors.forename: Kensaku
authors.initials: K
authors.lastname: Mori
mesh_terms: D000368:Aged; D059925:Anatomic Landmarks / Q000000981:diagnostic imaging*; D005260:Female; D005743:Gastrectomy / Q000379:methods*; D006801:Humans; D020706:Laparoscopes; D010535:Laparoscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed
keywords: Laparoscopic gastrectomy; Laparoscopic surgery; Port placement; Stomach; Surgical planning