title: Clopidogrel use for reducing the rate of thrombosis in a rat model of microarterial anastomosis.
abstract: OBJECTIVE
  The national success rate for microvascular free tissue transfer is around 94%. However, in cases of failure, which is most often due to thrombosis in the vascular pedicle, the morbidity can be significant. Microvascular surgeons have used various pharmacologic agents to reduce thrombosis rates; however, none have been ideal. We examined the effects of clopidogrel bisulfate (Plavix), a member of the relatively new class of antiplatelet agents, on the rate of arterial thrombosis in a rat model.
  
  
  METHODS
  Prospective randomized, blinded.
  
  
  METHODS
  Tertiary care academic medical center.
  
  
  METHODS
  Male Sprague-Dawley rats weighing between 350 and 400 g.
  
  
  METHODS
  Clopidogrel or placebo via gavage. After waiting 2 hours for absorption and activation, the "tuck" model of microvascular anastomosis was performed on both femoral arteries. Arteries were transected after 3 hours and patency was assessed.
  
  
  METHODS
  Bleeding time was obtained by determining the time to clot after removal of 2 mm from the tail tip. Vessel patency was assessed after 3 hours in the clopidogrel-treated and control groups.
  
  
  RESULTS
  Of 33 arteries, 19 (58%) in the control group developed complete thrombosis by the end of the period compared with only 6 (19%) of 32 arteries in the group that received clopidogrel. Chi(2) analysis revealed this to be significant (P = .001). The mean (SD) bleeding time in the control group was 158 (44) seconds compared with 233 (48) seconds in the clopidogrel group.
  
  
  CONCLUSIONS
  Clopidogrel significantly reduced the rate of arterial thrombosis in a rat model of microvascular repair. The average bleeding time in the clopidogrel group was prolonged, suggesting that absorption and activation occurred. These preliminary data suggest a potential role for clopidogrel in select high-risk patients undergoing microvascular free tissue transfer.
authors.affiliation: Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, MA 02114, USA.
authors.forename: Vijay K
authors.initials: VK
authors.lastname: Nayak
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Deschler
mesh_terms: D000714:Anastomosis, Surgical / Q000009:adverse effects; D000818:Animals; D000077144:Clopidogrel; D004311:Double-Blind Method; D005263:Femoral Artery / Q000601:surgery*; D008297:Male; D008866:Microsurgery / Q000009:adverse effects; D023421:Models, Animal; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D011446:Prospective Studies; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013927:Thrombosis / Q000517:prevention & control*; D013988:Ticlopidine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D016896:Treatment Outcome; D014654:Vascular Patency
chemical_list: D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine