title: Safety profile of trocar and insufflation needle access systems in laparoscopic surgery.
abstract: BACKGROUND
  The most common laparoscopic complications are associated with trocar insertion. The purpose of this study was to develop an objective method of evaluating the safety profile of various access devices used in laparoscopic surgery.
  
  
  METHODS
  In 20 swine, 6 bladed and 2 needle access devices were evaluated. A force profile was determined by measuring the force required to drive the trocar or needle through the fascia and into the peritoneum, at 0 and 10 mmHg. The amount of tissue deformation, the length of blade exposed, and the duration of exposure were measured using a high-speed digital imaging system.
  
  
  RESULTS
  The needle system without the sheath required the least driving force and had the most favorable force profile. In contrast, the bladed, nonretractable trocar system required a higher driving force and a rapid loss of resistance. Insertion under a pneumoperitoneum did not significantly alter the force profile of the various access devices except for the amount of tissue deformation. With the bladed system, the blade itself was exposed for an average of 0.5 to 1.0 seconds for a distance of 4.5 to 5.0 cm. In comparison, the needle system was exposed for 0.2 seconds for a distance of 1.8 cm.
  
  
  CONCLUSIONS
  We developed a reproducible method of measuring the forces required to place the access systems, their pattern of resistance loss, and the characteristics of the blade exposure. These parameters may provide an adjunctive and objective measurement of safety, allowing for more direct comparison between various trocar designs.
authors.affiliation: Robotic Research and Training Center, Department of Urology, Children's Hospital Boston and Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Carlo C
authors.initials: CC
authors.lastname: Passerotti
authors.forename: Nikolai
authors.initials: N
authors.lastname: Begg
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Penna
authors.forename: Ana Maria A M S
authors.initials: AM
authors.lastname: Passerotti
authors.forename: Katia R M
authors.initials: KR
authors.lastname: Leite
authors.forename: Alberto Azoubel
authors.initials: AA
authors.lastname: Antunes
authors.forename: Miguel
authors.initials: M
authors.lastname: Srougi
authors.forename: Alan B
authors.initials: AB
authors.lastname: Retik
authors.forename: Hiep T
authors.initials: HT
authors.lastname: Nguyen
mesh_terms: D000818:Animals; D004867:Equipment Design; D004869:Equipment Safety; D007431:Intraoperative Complications; D010535:Laparoscopy / Q000379:methods*; D009339:Needles; D011028:Pneumoperitoneum, Artificial / Q000295:instrumentation*; D011312:Pressure; D015203:Reproducibility of Results; D018709:Statistics, Nonparametric; D013525:Surgical Instruments; D013552:Swine