Influence of the use of laser phototherapy (lambda660 or 790 nm) on the survival of cutaneous flaps on diabetic rats.
OBJECTIVE
The aim of this study was to assess and compare the effects of laser phototherapy (LPT) on cutaneous flaps on diabetic rats.


BACKGROUND
Diabetes mellitus is characterized by high blood glucose levels. Its main complications are delayed wound healing, an impaired blood supply, and a decrease in collagen production. Cutaneous flaps are routinely used in several surgical procedures, and most failures are related to poor blood supply. LPT has been studied using several healing models.


METHODS
Twelve Wistar rats were randomized into three groups: group 1 (G1; diabetic animals without treatment), group 2 (G2; diabetic animals irradiated with lambda680 nm), and group 3 (G3; diabetic animals irradiated with lambda790 nm). Diabetes was induced with streptozotocin. A 2- x 8-cm cutaneous flap was raised on the dorsum of each animal, and a plastic sheet was introduced between the flap and the bed to cause poor blood supply. Nonirradiated animals acted as controls. The dose per session was 40 J/cm(2). Laser light was applied transcutaneously and fractioned on 16 contact points at the wound margins (16 x 2.5 J/cm(2)). Animal death occurred on day 8 after surgery. Specimens were taken, processed, cut, stained with eosin (HE) and sirius red, and underwent histological analysis.


RESULTS
It is shown that accute inflammation was mostly discrete for G3. Chronic inflammation was more evident for G2. Fibroblast number was higher for G3. Angiogenesis was more evident for G3. Necrosis was more evident for G2. Statistical analysis among all groups showed significant differences (p = 0.04) on the level of acute inflammation between G1 and G3, tissue necrosis between G1 and G2 (p = 0.03), chronic inflammation between (p = 0.04), fibroblastic proliferation between G2 and G3 (p = 0.05), and neovascularization between G2 and G3 (p = 0.04).


CONCLUSIONS
LPT was effective in increasing angiogenesis as seen on irradiated subjects and was more pronounced when IR laser light was used.
Santos
Nicole R S
NR
School of Dentistry, Federal University of Bahia, Salvador, Bahia, Brazil.
dos Santos
Jean N
JN
dos Reis
João A
JA
Oliveira
Priscila C
PC
de Sousa
Ana Paula C
AP
de Carvalho
Carolina M
CM
Soares
Luiz G P
LG
Marques
Aparecida M C
AM
Pinheiro
Antonio Luiz B
AL
D000818:Animals; D003921:Diabetes Mellitus, Experimental; D006085:Graft Survival / Q000528:radiation effects*; D028022:Low-Level Light Therapy; D008297:Male; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D013524:Surgical Flaps