title: Experimental model of degloving injury in rats: effect of allopurinol and pentoxifylline in improving viability of avulsed flaps.
abstract: BACKGROUND
  Degloving injuries may be a challenge when it comes to deciding the surgical approach to be used. Repositioning of the flap and suturing are faster and more straightforward, but often these procedures often lead to total or partial loss of the avulsed flap. Pharmacological agents with vascular properties that enhance the viability of the reattached flap could be beneficial to patients with degloving injuries. Experimental models with which to test this hypothesis are scarce. An experimental model reproducing a degloving injury of the hind limb of rats was developed in our department, and the effects of pentoxifylline (Ptx) and allopurinol (Alp) were assessed.
  
  
  METHODS
  In all, 3 groups of rats were studied (25 rats each). A hind limb degloving model was used in all groups, resulting in a reverse flow flap. The flap was then repositioned and sutured. The control (Ct) group received only saline solution, the Ptx group received pentoxifylline (25 mg/kg), and the Alp group received allopurinol (45 mg/kg). The rats were observed for 7 days, after which they were killed, and the flap was removed. The total area of the avulsed flap and the necrotic area were measured.
  
  
  RESULTS
  The median total flap area (cm) was 5.6 for the Ct group, 5.5 for the Ptx group, and 5.8 for the Alp group (P = 0.9465). Thus, the flaps were similar. The median necrotic flap area (cm) was 3.3 for the Ct group, 2.3 for the Ptx group, and 1.9 for the Alp group (P = 0.0001). There was a statistical difference between the Ct and Ptx groups and the Ct and Alp groups (P < 0.05).
  
  
  CONCLUSIONS
  The areas of necrosis observed in the degloved flaps of the rats' hind limbs were smaller in the pentoxifylline and allopurinol groups. Although allopurinol seems to be more efficient, the difference was not significant.
authors.affiliation: Division of Plastic Surgery, University of São Paulo, São Paulo, Brazil. drdimasandre@gmail.com
authors.forename: Dimas A
authors.initials: DA
authors.lastname: Milcheski
authors.forename: Hugo A
authors.initials: HA
authors.lastname: Nakamoto
authors.forename: Paulo
authors.initials: P
authors.lastname: Tuma
authors.forename: Lucas
authors.initials: L
authors.lastname: Nóbrega
authors.forename: Marcus C
authors.initials: MC
authors.lastname: Ferreira
mesh_terms: D000493:Allopurinol / Q000494:pharmacology*; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D006085:Graft Survival / Q000187:drug effects; D006614:Hindlimb / Q000293:injuries / Q000601:surgery; D008297:Male; D009336:Necrosis / Q000473:pathology / Q000517:prevention & control; D010431:Pentoxifylline / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012867:Skin / Q000098:blood supply / Q000187:drug effects / Q000293:injuries / Q000473:pathology; D017695:Soft Tissue Injuries / Q000188:drug therapy / Q000473:pathology* / Q000601:surgery*; D013524:Surgical Flaps / Q000098:blood supply* / Q000473:pathology*; D014665:Vasodilator Agents / Q000494:pharmacology; D014969:Xanthine Oxidase / Q000037:antagonists & inhibitors
chemical_list: D000975:Antioxidants; D014665:Vasodilator Agents; D000493:Allopurinol; D014969:Xanthine Oxidase; D010431:Pentoxifylline