title: Placement of a covered polyester stent prevents complications from a colorectal anastomotic leak and supports healing: randomized controlled trial in a large animal model.
abstract: BACKGROUND
  Anastomotic leaks after colorectal operation continue to be a significant cause of morbidity. A covered endoluminal stent could seal a leak and eliminate the need for diversion. The aim of this study was to test the efficacy of a temporary covered stent to prevent leak related complications.
  
  
  METHODS
  Sixteen adult pigs (80-120 lbs) underwent open transection of the rectosigmoid followed by anastomosis with a circular stapler. Eight animals (study group) underwent endoscopic placement of a 21-mm covered polyester stent. Eight control group animals were left without stents. In all animals, a 2-cm leak was created along the anterior portion of the anastomosis. The animals were killed after 2 weeks and evaluated for abdominal infection, fistulae, and adhesions. The anastomosis was excised and the following parameters were assessed by a pathologist blinded to treatment: mucosal interruption (mm), inflammatory response, collagen type I and III, granulation, and fibrosis (grade 0-4).
  
  
  RESULTS
  Stents were spontaneously expelled between postoperative days 6 and 9. At necropsy, none of the animals in the study group had leak related complications, whereas in the control group, 5 (63%) developed intraabdominal infection (4 abscesses, 1 fistula) at the anastomosis (P = .002). Dense adhesions to the anastomosis were found in 7 (88%) control animals. On histology, anastomotic sites in the study group had significantly less mucosal interruption and granulation. Two pigs in the study group died on postoperative day 7, one due to evisceration and one from bladder necrosis. The mortality result is not different from controls (P = .47), both events seem to be unrelated to stent placement.
  
  
  CONCLUSIONS
  Temporary placement of a covered polyester stent across a colorectal anastomosis prevents leak-related complications and supports the healing of anastomotic leaks.
authors.affiliation: Department of General Surgery, University of Missouri, Columbia, MO 65212, USA.
authors.forename: Zurab
authors.initials: Z
authors.lastname: Tsereteli
authors.forename: Emanuel
authors.initials: E
authors.lastname: Sporn
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Geiger
authors.forename: Dava
authors.initials: D
authors.lastname: Cleveland
authors.forename: Shellaine
authors.initials: S
authors.lastname: Frazier
authors.forename: Arthur
authors.initials: A
authors.lastname: Rawlings
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Bachman
authors.forename: Brent W
authors.initials: BW
authors.lastname: Miedema
authors.forename: Klaus
authors.initials: K
authors.lastname: Thaler
mesh_terms: D000714:Anastomosis, Surgical / Q000009:adverse effects; D000818:Animals; D020099:Coated Materials, Biocompatible; D012809:Colon, Sigmoid / Q000473:pathology / Q000601:surgery*; D004195:Disease Models, Animal; D008297:Male; D011091:Polyesters; D012007:Rectum / Q000473:pathology / Q000601:surgery*; D012828:Silicones; D015607:Stents; D017792:Surgical Stapling / Q000009:adverse effects*; D013529:Surgical Wound Dehiscence / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D013552:Swine; D014945:Wound Healing
chemical_list: D020099:Coated Materials, Biocompatible; D011091:Polyesters; D012828:Silicones