title: Effects of ischemic preconditioning of different intraoperative ischemic times of vascularized bone graft rabbit models.
abstract: BACKGROUND
  Ischemic preconditioning has been shown to improve the outcomes of hypoxic tolerance of the heart, brain, lung, liver, jejunum, skin, and muscle tissues. However, to date, no report of ischemic preconditioning on vascularized bone grafts has been published.
  
  
  METHODS
  Sixteen rabbits were divided into four groups with ischemic times of 2, 6, 14, and 18 hours. Half of the rabbits in each group underwent ischemic preconditioning. The osteomyocutaneous flaps consisted of the tibia bone, from which the overlying muscle and skin were raised. The technique of ischemic preconditioning involved applying a vascular clamp to the pedicle for 3 cycles of 10 minutes each. The rabbits then underwent serial plain radiography and computed tomography imaging on the first, second, fourth, and sixth postoperative weeks. Following this, all of the rabbits were sacrificed and histological examinations were performed.
  
  
  RESULTS
  The results showed that for clinical analysis of the skin flaps and bone grafts, the preconditioned groups showed better survivability. In the plain radiographs, except for two non-preconditioned rabbits with intraoperative ischemic times of 6 hours, all began to show early callus formation at the fourth week. The computed tomography findings showed more callus formation in the preconditioned groups for all of the ischemic times except for the 18-hour group. The histological findings correlated with the radiological findings. There was no statistical significance in the difference between the two groups.
  
  
  CONCLUSIONS
  In conclusion, ischemic preconditioning improved the survivability of skin flaps and increased callus formation during the healing process of vascularized bone grafts.
authors.affiliation: Reconstructive Sciences Unit, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia.
authors.forename: Ahmad Sukari
authors.initials: AS
authors.lastname: Halim
authors.forename: Wan Syazli Rodzaia
authors.initials: WS
authors.lastname: Wan Ahmad Kamal
authors.forename: Norizal Mohd
authors.initials: NM
authors.lastname: Noor
authors.forename: Shafie
authors.initials: S
authors.lastname: Abdullah
keywords: Free tissue flaps; Ischemic preconditioning; Microsurgery