title: Effect of photodynamic therapy on the critical primary ischemic time of fasciocutaneous flaps.
abstract: BACKGROUND
  Photodynamic therapy (PDT) may be used as an adjuvant intraoperative therapy to improve locoregional control. PDT has been shown to delay wound healing. This raises concern about PDTs effect on survival of fasciocutaneous flaps.
  
  
  OBJECTIVE
  Evaluate the effect of 1) PDT on the critical ischemic time in a rat fasciocutaneous flap model and 2) photosensitizer activation by the surgical light source.
  
  
  METHODS
  A fasciocutaneous flap, based on the left inferior epigastric vessels, was used. Ischemic times of 2, 4, 6, 8, 10, and 12 hours were induced by clamping the vascular pedicle. Animals were randomly divided into five groups: ischemia only, group I; light treatment to wound bed, group II; Photofrin before surgery with the flap elevated without a fiber optic head light, group III, or with a headlight, group IV; Photofrin prior to surgery with light treatment to the wound bed, group V. Flap survival was assessed on postoperative day 7.
  
  
  RESULTS
  The critical primary ischemic time of group V (PDT) was significantly less (P < .05) than groups I, II, III, and IV. There was no statistical difference in the critical primary ischemic time when a fiber optic headlight was used (group III vs. group IV).
  
  
  CONCLUSIONS
  Intraoperative PDT significantly reduces the critical primary ischemic time of the rat fasciocutaneous flap. White light illumination of the operative field does not result in photosensitizer activation and has no effect on the critical primary ischemic time.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, State University of New York at Buffalo, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Belmont
authors.forename: N
authors.initials: N
authors.lastname: Marabelle
authors.forename: T S
authors.initials: TS
authors.lastname: Mang
authors.forename: M K
authors.initials: MK
authors.lastname: Wax
mesh_terms: D000818:Animals; D017323:Dihematoporphyrin Ether / Q000494:pharmacology*; D006085:Graft Survival / Q000187:drug effects*; D008297:Male; D010778:Photochemotherapy / Q000379:methods; D017319:Photosensitizing Agents / Q000494:pharmacology*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013524:Surgical Flaps; D013997:Time Factors
chemical_list: D017319:Photosensitizing Agents; D017323:Dihematoporphyrin Ether