title: Comparative study of NOTES rectosigmoidectomy in a swine model: E-NOTES vs. P-NOTES.
abstract: OBJECTIVE
  Several reports have demonstrated the safety of pure natural-orifice transluminal endoscopic surgery (P-NOTES) using transanal endoscopic microsurgery (TEM) and embryonic NOTES (E-NOTES; laparoscopic surgery through the umbilicus). This study was performed to compare the safety and applicability of NOTES rectosigmoidectomy between E-NOTES and P-NOTES in a swine model.
  
  
  METHODS
  E-NOTES was conducted through a single port using laparoscopic instruments (n = 11). P-NOTES was performed using TEM with transgastric endoscopic assistance (n = 11). Gastrotomies were created using a needle knife and the balloon dilatation technique, and closed using T-anchors. Blood samples were collected to evaluate changes in systemic cytokine levels during the preoperative and postoperative periods; operative outcomes were also evaluated and compared between the groups. The necropsy findings were recorded after sacrifice at 1 week after the procedure.
  
  
  RESULTS
  The mean operative time for P-NOTES was significantly longer than that for E-NOTES (239 vs. 103 minutes, P < 0.001). The mean distance from the anal verge to colorectal anastomosis in the P-NOTES group was significantly less than that in the E-NOTES group (2.9 vs. 17.6 cm, P < 0.001). On necropsy, the complication rate of P-NOTES was higher than that of E-NOTES, but without statistical significance (54.5 % vs. 18.2 %, P = 0.091). The differences in changes in TNF-α, C-reactive protein, interleukin-6, and interleukin-1β between P-NOTES and E-NOTES were not significant.
  
  
  CONCLUSIONS
  E-NOTES rectosigmoidectomy in the swine model is safe, but remains challenging for use in pelvic dissection. P-NOTES rectosigmoidectomy using TEM may be a promising tool for pelvic dissection, but the transgastric approach involves a high degree of risk.
authors.affiliation: Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors.forename: D K
authors.initials: DK
authors.lastname: Sohn
authors.forename: S-Y
authors.initials: SY
authors.lastname: Jeong
authors.forename: J W
authors.initials: JW
authors.lastname: Park
authors.forename: J S
authors.initials: JS
authors.lastname: Kim
authors.forename: J H
authors.initials: JH
authors.lastname: Hwang
authors.forename: D-W
authors.initials: DW
authors.lastname: Kim
authors.forename: S-B
authors.initials: SB
authors.lastname: Kang
authors.forename: J H
authors.initials: JH
authors.lastname: Oh
mesh_terms: D018784:Abdominal Abscess / Q000209:etiology; D001003:Anal Canal; D000818:Animals; D001201:Ascites / Q000209:etiology; D002097:C-Reactive Protein / Q000378:metabolism; D003082:Colectomy / Q000009:adverse effects / Q000379:methods*; D006406:Hematoma / Q000209:etiology*; D053583:Interleukin-1beta / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D010535:Laparoscopy; D008297:Male; D023421:Models, Animal; D057605:Natural Orifice Endoscopic Surgery / Q000009:adverse effects / Q000379:methods*; D010532:Peritoneal Diseases / Q000209:etiology*; D013530:Surgical Wound Infection / Q000209:etiology; D013552:Swine; D013997:Time Factors; D000267:Tissue Adhesions / Q000209:etiology; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D014472:Umbilicus
chemical_list: D053583:Interleukin-1beta; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein