臍の解剖所見より改良したOpen法

抄録

Objective: The umbilicus is commonly used for the insertion of the first trocar in laparoscopic surgery, but detailed anatomical information is limited. This study aimed to elucidate umbilical anatomy to improve the open technique for trocar insertion.

Method: The subumbilical region was observed from within the abdominal cavity using a 4K camera during both open and laparoscopic procedures. The open trocar insertion approach was further assessed through close-up observation, and the umbilical region was examined using magnetic resonance imaging (MRI). Refinements to the open technique were made, and its utility was evaluated by comparing insertion times under three conditions using the Mann-Whitney U test: (1) a resident before modification, (2) the same resident after modification, and (3) two qualified gynecologists in endoscopic surgery.

Results: Intraabdominal observations revealed a depression directly below the umbilicus, with increased preperitoneal fat compared to the surrounding area. The tissue in this depression appeared thin, as ambient light passed through it when the camera light was turned off. Close-up observation during open insertion revealed findings suggestive of peritoneal fusion, which were corroborated by MRI evidence. The refined “preperitoneal fat compression” method, developed based on these anatomical insights, significantly reduced the resident’s insertion time (median) from 446.5 s to 139.5 s (p = 0.048), which was no significant difference with the time taken by the qualified gynecologists (125.5 s, p = 0.65).

Conclusion: Preperitoneal fat compression, a refined open trocar insertion method based on new anatomical insights about the umbilicus, improves the safety of first trocar insertion.