Feasibility of transgastric and transcolonic peritoneoscopy combined with intraperitoneal endoscopic ultrasonography

Background: If Natural Orifice Transluminal Endoscopic Surgery (NOTES) peritoneoscopy is to become an alternative to diagnostic laparoscopy, it has to cover its full diagnostic potentials. Until now there have been no reports of intraperitoneal endoscopic ultrasonography (EUS) in NOTES.

Objective: To assess feasibility of transgastric and transcolonic NOTES peritoneoscopy combined with intraperitoneal EUS in a porcine model.

Methods: We performed 12 acute experiments on six 35–40 kg pigs under general anesthesia. Randomisation was performed to determine order of approach (transgastric or transcolonic). Previous to access, two T-tags were placed to facilitate closure. After peritoneal access, systematic peritoneoscopy was performed according to a pre-assessed list of locations. Locations included: peritoneum, diaphragm, surface of liver, hepatoduodenal ligament, omentum, anterior stomach and pelvis. For each visualized location one point was scored and one point added if touched as well, leading to a maximum score of 24 points. Subsequently, the endoscope was exchanged for linear EUS-scope (GF-UCT140, Olympus Medical Systems). The estimated percentage of visualization of different parts of the liver was recorded (0: not visible; 1: 30%; 2: 60%; 3: 100%; maximum score: 12 points). After withdrawal the protocol was repeated using the second natural orifice. The gastrotomy and colotomy were closed using multiple T-tags and/or endoclips.

Results: Access was achieved without difficulties at all 12 sites. Peritoneoscopy via the transgastric approach resulted in a median of 23 points (range 20–24), via the transcolonic approach the maximum of 24 points was recorded in all pigs (p = 0.102). Via the transgastric approach it was not possible to adequately visualise (the inferior) liver surface in three pigs. transgastric-EUS resulted in a median of 11 points (range 6–12) and transcolonic-EUS in a median of 12 points (range 8–12) (p = 0.317). At necropsy 2/6 gastrotomies and 4/6 colotomies were airtight.

Conclusion: Transluminal intraperitoneal EUS is feasible during NOTES peritoneoscopy and results in an adequate ultrasonographic imaging of the liver. The transcolonic approach might be superior to the transgastric approach.