title: Endoscopic ultrasound-guided inoculation of transmissible venereal tumor in the colon: A large animal model for colon neoplasia.
abstract: BACKGROUND
  To develop and evaluate the feasibility of emerging interventions, animal models with accurate anatomical environment are required.
  
  
  OBJECTIVE
  We aimed to establish a clinically relevant colorectal tumor model with canine transmissible venereal tumor (CTVT) utilizing endoscopic ultrasound (EUS) imaging guidance.
  
  
  METHODS
  Survival study using a canine model.
  
  
  METHODS
  Endoscopic animal research laboratory at a tertiary cancer center.
  
  
  METHODS
  This study involved five canines.
  
  
  METHODS
  A colorectal tumor model was established and evaluated in five canines under cyclosporine immune suppression. Under endoscopic imaging guidance, saline was injected into the submucosal layer forming a bleb. Subsequently, CTVT was inoculated into the bleb under EUS guidance. Endoscopy was the primary method of assessing tumor growth. Tumors developed in 60-130 days. Upon detection of lesions >1 cm, the animals were euthanized and the tumors were harvested for histopathological characterization.
  
  
  METHODS
  Success rate of tumor growth. The presence or absence of vasculature inside tumors.
  
  
  RESULTS
  Colorectal tumor successfully developed in three out of the five animals (60%). Among the ones with tumor growth, average inoculated CTVT volume, incubation time, and tumor size was 1.8 cc, 65.7 days, and 2.0 cm, respectively. The two animals without tumor growth were observed for >100 days. In all the tumors, vascular structure was characterized with CD31 imunohistochemical stain.
  
  
  CONCLUSIONS
  Small number of animals.
  
  
  CONCLUSIONS
  We succeeded in creating a new colorectal tumor canine model with CTVT utilizing EUS.
authors.affiliation: Department of Gastroenterology, Hepatology and Nutrition, UT MD Anderson Cancer Center, Houston,Texas, USA.
authors.forename: Manoop S
authors.initials: MS
authors.lastname: Bhutani
authors.forename: Rajesh
authors.initials: R
authors.lastname: Uthamanthil
authors.forename: Rei
authors.initials: R
authors.lastname: Suzuki
authors.forename: Anil
authors.initials: A
authors.lastname: Shetty
authors.forename: Sherry A
authors.initials: SA
authors.lastname: Klumpp
authors.forename: William
authors.initials: W
authors.lastname: Nau
authors.forename: Roger Jason
authors.initials: RJ
authors.lastname: Stafford