title: Laparoscopic Rectal Dissection Assisted by Transanal Endoluminal Videoendoscopy Through a Blunt Tip Trocar.
abstract: OBJECTIVE
  Laparoscopic resection is a well-established approach for colorectal cancer surgery. In patients with rectal cancer treated by neoadjuvant chemoradiotherapy, it may be difficult to identify a clear safety margin for endostapling and subsequent anastomosis. We designed an innovative technical approach to assist colorectal anastomosis in these patients.
  
  
  METHODS
  A four-trocar laparoscopic approach is used. After exploration of the abdominal cavity, the left colic flexure is completely mobilized. Using a medial to lateral approach, the inferior mesenteric artery and vein are divided between clips, and the left colon proximal to the tumor is transected with a linear stapler. A total mesorectal excision is performed. At this point, if the free margin distal to the tumor site cannot be clearly identified, a blunt tip trocar (BTT, 10 mm; Medtronic, Minneapolis, MN) is inserted into the anus and the proximal foam sponge is secured to the anal verge to avoid displacement and gas leakage. Under low flow rate gas insufflation, a 0° scope inserted into the trocar allows a clear observation of the distal margin of the lesion and guides the low rectal laparoscopic dissection and the precise placement of the stapler. The BTT is then removed to perform the transanal colorectal anastomosis; at the end of the procedure, the BTT can be reinserted to check the anastomosis for bleeding and leakage.
  
  
  RESULTS
  We used this novel technique on 3 patients who underwent neoadjuvant therapy for T3 rectal cancer. In all of them, identification of the distal tumor margin was difficult at laparoscopy. All surgical procedures were safely completed and resulted in R0 resection. The average length of stay was 6 days. All patients were free from recurrences at 1 year follow-up.
  
  
  CONCLUSIONS
  Endoluminal videoendoscopy through a transanal BTT is a useful ancillary technique to achieve a safe free margin during low rectal resection.
authors.affiliation: Department of Biomedical Sciences for Health, IRCCS Policlinico San Donato, University of Milan Medical School , Milano, Italy .
authors.forename: Emanuele
authors.initials: E
authors.lastname: Asti
authors.affiliation: Department of Biomedical Sciences for Health, IRCCS Policlinico San Donato, University of Milan Medical School , Milano, Italy .
authors.forename: Andrea
authors.initials: A
authors.lastname: Lovece
authors.affiliation: Department of Biomedical Sciences for Health, IRCCS Policlinico San Donato, University of Milan Medical School , Milano, Italy .
authors.forename: Luigi
authors.initials: L
authors.lastname: Bonavina
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology / Q000601:surgery*; D000368:Aged; D000714:Anastomosis, Surgical / Q000379:methods; D005260:Female; D006801:Humans; D010535:Laparoscopy / Q000379:methods; D008297:Male; D020360:Neoadjuvant Therapy; D009364:Neoplasm Recurrence, Local / Q000473:pathology / Q000601:surgery*; D012004:Rectal Neoplasms / Q000473:pathology / Q000601:surgery*; D013525:Surgical Instruments; D000067368:Transanal Endoscopic Surgery / Q000379:methods; D014741:Video Recording
keywords: colorectal anastomosis; laparoscopic anterior resection; rectal carcinoma; total mesorectal excision