title: Endoscopic ultrasound-assisted direct peritoneal visualization with a small-caliber scope: A proof of concept study in a swine model.
abstract: BACKGROUND
  Laparoscopic and natural orifice transluminal endoscopic surgery techniques can diagnose peritoneal findings that suggest tumor cell dissemination. However, they have not been incorporated into routine practice, mainly owing to their complexity. To develop a minimally invasive endoscopic technique for the diagnosis of peritoneal findings, we conducted feasibility study using an acute swine model.
  
  
  METHODS
  This study involved six domestic pigs. Trans-gastric access to the peritoneal cavity was performed utilizing an endoscopic ultrasound fine needle aspiration (EUS-FNA) technique. After dilation of the needle hole with a biliary dilatation catheter and balloon, a small-caliber scope was inserted into the peritoneal cavity. Peritoneal images were obtained with the scope and a high-resolution microendoscope (HRME). Main outcome measurements were technical feasibility and time needed to access the peritoneal cavity.
  
  
  RESULTS
  Direct visualization of the peritoneum was successful in all six pigs and gained access to the gross appearance of the peritoneal cavity. HRME imaging with topical contrast agent also obtained reasonable quality images representing nuclei of the peritoneal mesothelium. Average operation time from the initiation of EUS-FNA to acquiring peritoneal images was 26.5 min (range 15-40 min). Autopsy found no damage to the adjacent organs, and stomach wall defects were tightly closed with hemostasis clips.
  
  
  CONCLUSIONS
  EUS-assisted direct peritoneal visualization with small-caliber scope is technically feasible. HRME may assist in the diagnosis of findings on the peritoneum.
authors.affiliation: Department of Gastroenterology, Hepatology and Nutrition, The University of Texas MD Anderson Cancer Center, Texas, USA ; Department of Gastroenterology and Rheumatology, Fukushima Medical University School of Medicine, Fukushima, Japan.
authors.forename: Rei
authors.initials: R
authors.lastname: Suzuki
authors.affiliation: Department of Gastroenterology, Hepatology and Nutrition, The University of Texas MD Anderson Cancer Center, Texas, USA.
authors.forename: Manoop S
authors.initials: MS
authors.lastname: Bhutani
authors.affiliation: Department of Neurosurgery, The University of Texas Medical School at Houston, Texas, USA.
authors.forename: Dongsuk
authors.initials: D
authors.lastname: Shin
authors.affiliation: Department of Gastroenterology, Fukushima Medical University Aizu Medical Center, Aizuwakamatsu, Fukushima, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Irisawa
authors.affiliation: Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, Texas, USA.
authors.forename: Jason B
authors.initials: JB
authors.lastname: Fleming
authors.affiliation: Department of Bioengineering, Rice University, Houston, Texas, USA.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Richards-Kortum
authors.affiliation: Department of Gastroenterology and Rheumatology, Fukushima Medical University School of Medicine, Fukushima, Japan.
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Ohira
keywords: Cancer staging; endoscopic ultrasound-guided fine needle aspiration; natural orifice transluminal endoscopic surgery; peritoneoscopy; tumor implant