Purpose: In this research the effects of low power He-Ne laser on survival of skin flap of rats by measuring survival area and biomechanical and histological method were studied.
Materials & Methods: 50 male 3 months old sprague dawley rats weighing 285±30 gr randomly were selected. On the dorsum of each rat under sterile conditions and general anesthesia one 20´100 mm full thickness random skin flap was made. The base of the falp was distal (caudal) of rat. The day of surery was designated as day zero (0) and the consecutive days, days 1, 2, etc. The rats were divided into following groups by matching sampling method:
I. This group at the surrey day no received laser and laser radiation was started from day 1 until day 7 one time per day.
II. In this group laser radiation was started immediately after surgery and coritinued every 6 hours for 24 hours, then the laser radiation continued one time per day unitl day 7.
III. This group since 5 days prior to the operation received laser radiation one time per and day and also immediately after every 6 hours for 24 hours and then radiation continued one time per day until day 7.
IV. In this group laser radiation started from 5 day prior to the operation one time per. At the day of surgery they no received laser radiation and it again started from day until day 7 one time per day.
V. This group was control and no received laser radiation. The instrument was a product of Iranian Organization of Atomic Energy (Power out put was 5 MW and wavelength was 632.8nm). In this study energy density of laser radiation was 0.2 J/cm2.
At the of surgery and day 7 borders of survival part of each flap was marked no a sterile transparency paper. After that, the marked area was measured by a milimetric paper with 1×1mm grids. For histological study samples from survival area obtained and prepared for staining and stained by hematoxyline and eosin and watery solution of toluidine blue 1% and unmber and density of vessels and unmber of mast were counted and calculated.
At the day 7 after killing rats by chloroform one longitudinal sample and one transverse sample that including wound borders were obtained from survival part of each flap. Samples were tested by a tensiometer machine. Data were analysed by one way analysis of varience and multiple comparisons with least significant difference.
Results: Survival area differed significantly at day 7 and highest of which belongs to group 3. Between (3 and 5) and (3 and 1) groups (P=0.0454). Difference of length at tensile strength (P=0.02) and force at fracture point (P=0.03) and…