title: Transanal endoscopic microsurgical platform for natural orifice surgery.
abstract: BACKGROUND
  The excitement surrounding natural orifice transluminal endoscopic surgery (NOTES) remains tempered by concerns over safe access and closure of transvisceral enterotomies. Research in NOTES has commonly been described as using an oral transgastric access point. Transanal endoscopic microsurgery (TEM) is a minimally invasive technique for a full-thickness resection of rectal tumors and with suture closure of the resultant defect with highly specialized instruments. This technique has been used clinically in human beings for more than 2 decades. Entry into the peritoneal cavity during a resection of rectosigmoid lesions has been described, and safe closure can be obtained.
  
  
  OBJECTIVE
  To assess the feasibility of transrectal NOTES procedures by using TEM instrumentation.
  
  
  METHODS
  Three porcine and 3 human cadaver models were studied by using standard TEM instrumentation and flexible endoscopes. NOTES peritoneal access, a peritoneoscopy, a liver biopsy, and colorectal resections were performed.
  
  
  RESULTS
  True NOTES procedures facilitated with TEM instrumentation were successfully completed.
  
  
  CONCLUSIONS
  This was a preclinical study, and several challenges to bridging to human clinical use exist: TEM instruments are currently designed for intraluminal tasks low in the pelvis, with 5-mm to 10-mm port sizes; the cost of the TEM instruments and insufflation system; and the learning curve to perform TEM closure.
  
  
  CONCLUSIONS
  Our preclinical study demonstrated the feasibility of several transrectal NOTES procedures, colorectal resection, and anastomosis when using TEM instrumentation. We, therefore, suggest TEM as a portal for NOTES.
authors.affiliation: Gastrointestinal and Minimally Invasive Surgery Division, Legacy Health System, The Oregon Clinic, PC, Portland, Oregon 97210, USA.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Denk
authors.forename: Lee L
authors.initials: LL
authors.lastname: Swanström
authors.forename: Mark H
authors.initials: MH
authors.lastname: Whiteford
mesh_terms: D000714:Anastomosis, Surgical; D000818:Animals; D001706:Biopsy / Q000379:methods; D002102:Cadaver; D003082:Colectomy / Q000379:methods; D003106:Colon / Q000601:surgery; D005240:Feasibility Studies; D006801:Humans; D010535:Laparoscopy / Q000379:methods; D008099:Liver / Q000473:pathology; D008866:Microsurgery / Q000379:methods; D019060:Minimally Invasive Surgical Procedures; D011028:Pneumoperitoneum, Artificial; D020700:Proctoscopes; D011351:Proctoscopy / Q000379:methods*; D012007:Rectum / Q000601:surgery*; D017792:Surgical Stapling; D034421:Sus scrofa