Related Experiment Video
Updated: Oct 7, 2025

Intraoperative Gastroscopy for Tumor Localization in Laparoscopic Surgery for Gastric Adenocarcinoma
Published on: August 9, 2016
Initial entry via the left upper quadrant with an optical trocar in laparoscopic bariatric surgery
Manabu Amiki1, Yasuhiro Ishiyama1, Tatsunosuke Harada1
1Kawasaki Saiwai Hospital, Kawasaki City, Japan.
Introduction:
Laparoscopic bariatric surgery (BS) is not readily performed in Japan. To facilitate safe initial access to the abdominal cavity, we insert an optical viewing trocar at a unique site in the left upper quadrant (LUQ). Herein, we describe the technique, its advantages, and outcomes.
Materials And Surgical Technique:
Briefly, the optical trocar is inserted just below the left subcostal margin, 8 cm from the midline. On insertion, layers of the abdominal wall are visualized on the monitor. Depending on the angle of insertion, five, seven, or eight layers are seen.
Discussion:
In assessing our initial entry technique, used in 21 obese patients undergoing laparoscopic sleeve gastrectomy, we found median insertion time to be 25 seconds. There were no related complications. In nearly all (20/21) patients, the abdominal wall was visualized as seven layers: subcutaneous fat, anterior rectus sheath, rectus abdominis muscle, posterior rectus sheath, transverse abdominis muscle, transversalis fascia, and peritoneum. Understanding the layers of the abdominal wall visualized during optical trocar insertion in the LUQ will provide for safe and rapid initial entry in patients undergoing laparoscopic BS and can further the widespread acceptance of laparoscopic BS.

