Transgastric diagnostic peritoneoscopy is safe and feasible. This study demonstrates the initial steps of NOTES in humans, providing a potential platform for incisionless surgery. Technical issues, including instrumentation, visualization, intra-abdominal manipulation, and gastric closure need further development.

BACKGROUND Intraoperative cholangiography (IOC) is the current gold standard for biliary imaging during laparoscopic cholecystectomy (LC). However, utilization of IOC remains low. Near Infrared Fluorescence Cholangiography (NIRF-C) is a novel, noninvasive method for real-time, intraoperative biliary mapping. Our aims were to assess the safety and efficacy of NIRF-C for identification of biliary anatomy during LC. METHODS Patients were administered indocyanine green (ICG) prior to surgery. NIRF-C was used to identify extrahepatic biliary structures before, and after partial and complete dissection of Calot's triangle. Routine IOC was performed in each case. Identification of biliary structures using NIRF-C and IOC, and time required to complete each procedure were collected. RESULTS Eighty-two patients underwent elective LC with NIRF-C and IOC. Mean age and BMI were 42.6±13.7 years and 31.5±8.2 kg/m2, respectively. ICG was administered 73.8±26.4 minutes prior to incision. NIRF-C was significantly faster than IOC (1.9±1.7 vs. 11.8±5.3 minutes, p<0.001). IOC was unobtainable in 20 (24.4%) patients while NIRF-C did not visualize biliary structures in 4 (4.9%) patients. After complete dissection, the rates of visualization of the cystic duct, common bile duct, and common hepatic duct using NIRF-C were 95.1%, 76.8%, and 69.5%, respectively, compared to 72.0%, 75.6%, and 74.3% for IOC. In 20 patients where IOC could not be obtained, NIRF-C successfully identified biliary structures in 80% of the cases. Higher BMI was not a deterrent to visualization of anatomy with NIRF-C. No adverse events were observed with NIRF-C. CONCLUSIONS NIRF-C is a safe and effective alternative to IOC for imaging extrahepatic biliary structures during LC. This technique should be evaluated further under a variety of acute and chronic gallbladder inflammatory conditions to determine its usefulness in biliary ductal identification.

Transgastric instrumentation does contaminate the abdominal cavity but pathogens are clinically insignificant due to species or bacterial load. Patients on PPIs do have an increased bacterial load in the gastric aspirate, with no clinical significant infection.

There was no clinically significant contamination of the peritoneal cavity from the gastroscope after transgastric endoscopic instrumentation in humans. Transgastric instrumentation does contaminate the abdominal cavity but, the pathogens do not mount a clinically significant response in terms of either the species or the bacterial load.