Date of Award


Degree Type



Biological, Geological and Environmental Sciences

First Advisor

Weyman, Crystal

Subject Headings

Endoscopic surgery, Surgery, Orificial, NOTES, Endoscopy, Natural orifice surgery


Natural Orifice Translumenal Endoscopic Surgery (NOTES) avoids skin incisions by accessing the abdominal cavity through natural orifices. Benefits include less pain, fewer complications and no scars. The aims of this study were to evaluate safety and efficacy of access techniques for natural orifice surgery, to investigate safety and efficacy of closure methodologies and to compare the inflammatory response induced by NOTES with that following conventional surgery. Access techniques were evaluated for safety and efficacy by measuring resultant injury and time required to access the peritoneal cavity in an acute porcine model. Four different gastrotomy closure modalities were evaluated for safety and efficacy by measuring clinical data, evidence of infection and closure integrity in a chronic porcine study. Markers of inflammation were measured in a chronic study comparing NOTES to conventional surgery. 70 anterior transgastric access procedures were performed without any serious injury to adjacent organs. NOTES access required significantly longer than laparoscopic access. Of the seven methods evaluated none was significantly superior to others. In distinguishing between safe and unsafe alternate access sites, endoscopic ultrasound (EUS) provided a statistically significant difference for antral and posterior stomach access points but not for rectal access. Gastrotomy closure time varied widely for the four techniques evaluated. No leak was detected with any method and the strength of closure for each technique was equivalent to control. Three of the four methods resulted in injury and evidence of infection was found in all groups. Postoperative elevation of inflammatory markers was not significantly different between NOTES and laparoscopy except in the case of cortisol, which was greater in the laparoscopic group. This study supports the safety of anterior transgastric access while demonstrating the potential use of EUS in minimizing risks of injury at alternate sites. Likewise, evidence for the reliability of

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