title: Effects of antithrombogenic agents on microvenous anastomoses in a rat model.
abstract: OBJECTIVE
  To compare venous thrombosis rates among animals treated with aspirin, clopidogrel bisulfate, and ketorolac tromethamine using an anastomotic "tuck" model.
  
  
  METHODS
  Single-blind randomized animal study.
  
  
  METHODS
  An animal laboratory at a tertiary care academic referral center.
  
  
  METHODS
  Forty-two retired Lewis breeder rats divided into 3 equal groups.
  
  
  METHODS
  Before surgical intervention, 1 group received aspirin (10 mg/kg) through gavage; 1 group, clopidogrel bisulfate (5 mg/kg) through gavage; and the final group, ketorolac tromethamine (3 mg/kg) through intramuscular injection. Each rat was then anesthetized, and the femoral veins were prepared bilaterally. A 180° venotomy was made, and the vessels were anastomosed with the tuck model set-up for anastomotic failure. The vessels were checked for patency every 15 minutes for 2 hours after clamp removal.
  
  
  METHODS
  The rate of venous thrombosis and the time to thrombosis.
  
  
  RESULTS
  In both the aspirin and clopidogrel groups, 2 of 28 vessels (7%) were thrombosed. Thrombosis occurred in 3 of 28 vessels (11%) in the ketorolac group (P = .86). All thromboses in the aspirin and clopidogrel groups took place at 7.5 minutes after clamp removal. In the ketorolac group, the mean time to thrombosis was 7.5 minutes (range, 0-22.5 minutes). There was no difference in time to thrombosis among the 3 groups (P = .86).
  
  
  CONCLUSIONS
  Using a microvenous tuck model set-up for anastomotic failure, we found no difference in the rate of thrombosis or the time to thrombosis in rats pretreated with aspirin, clopidogrel, or ketorolac.
authors.affiliation: Division of Otolaryngology, Head and Neck Surgery, Mayo Clinic, Scottsdale, Arizona, USA. wayne.harsha@us.army.mil
authors.forename: Wayne J
authors.initials: WJ
authors.lastname: Harsha
authors.forename: Ryan L
authors.initials: RL
authors.lastname: Kau
authors.forename: Namou
authors.initials: N
authors.lastname: Kim
authors.forename: Richard E
authors.initials: RE
authors.lastname: Hayden
mesh_terms: D000714:Anastomosis, Surgical; D000818:Animals; D001241:Aspirin / Q000494:pharmacology; D000077144:Clopidogrel; D005268:Femoral Vein / Q000601:surgery; D020911:Ketorolac Tromethamine / Q000494:pharmacology; D008833:Microcirculation; D023421:Models, Animal; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D011897:Random Allocation; D051381:Rats; D013988:Ticlopidine / Q000031:analogs & derivatives / Q000494:pharmacology; D013997:Time Factors; D014654:Vascular Patency / Q000187:drug effects; D020246:Venous Thrombosis / Q000517:prevention & control*
chemical_list: D010975:Platelet Aggregation Inhibitors; D020911:Ketorolac Tromethamine; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin