NOTES abdominal exploration: a prospective comparative study of laparoscopy, transgastric NOTES and transcolonic NOTES in a porcine model

Aim: To evaluate the procedural differences and outcomes measures between laparoscopic, transgastric NOTES (TG), and transcolonic NOTES (TC).

Methods: 18 Adult white pigs were assigned to one of three arms: laparoscopic, TG or TC. Animals were kept NPO for 48 hours prior to procedure and pre-op antibiotics administered. Anti-septic technique and antibiotic lavage was utilized in TG and TC access. Colonic access was obtained with needle knife cautery and gastric with needle knife cautery and balloon dilatation. Laparoscopic access was achieved with standard trochars. Timed abdominal exploration was performed (20 min) with identification of 14 pre-determined organs recorded. Access and closure time were noted, and peritoneal fluid collected if present. Closures for NOTES procedures used endoloops, t-tags and endoclips. Animals were survived for 7–11days. Peritoneal fluid was sampled intra-op and upon sacrifice. Video logs were kept for all facets of the study.

Results: (1) Laparoscopic, (2) TG and (3) TC comparisons were as follow: Mean time for procedure in minutes (1) 30.1; (2) 42 ; (3) 35.5; Mean time for peritoneal access including preparation of closure prior to access (1) 1.5; (2) 34.5;(3) 1.7; Mean number of organs identified: (1) 14; (2) 12.5;(3) 14; Avg. organ identification time (1) 10; (2) All organs not identified; (3) 9.13; Avg. intraperitoneal time (1) 20;(2)16.83; (3) 20;Mean closure time (1) 6; (2) 13.16; (3) 7.8; number of adhesions (1) 50%; (2) 16%; (3) 33%. Interleukins 1-beta and IL-6 were tested. Interleukin analysis showed no statistical significance between access techniques or the presence of adhesions. In all groups IL-6 averaged < 15.298 intra-op and peaked at 111.73 at necropsy. IL1B averaged < 15.83 intra-op and peaked at 17.11 at necropsy.

Conclusions: NOTES peritoneal exploration is comparable to laparoscopy for simple organ identification. Gastric access yields longer access, closure and procedure times when compared to colonic or laparoscopic access, however, is associated with the lowest adhesion burden. Additionally, peritoneal structures are more readily identified transcolonically and laparoscopically. Differences in interleukin analysis were minimal. None of these preliminary results reached statistical significance, however studies are ongoing.