Carlos Eduardo Pinfildi

Effect of low level laser therapy (830 nm) with different therapy regimes on the process of tissue repair in partial lesion calcaneous tendon

Calcaneous tendon is one of the most damaged tendons, and its healing may last from weeks to months to be completed. In the search after speeding tendon repair, low intensity laser therapy has shown favorable effect. To assess the effect of low intensity laser therapy on the process of tissue repair in calcaneous tendon after undergoing a partial lesion.

Experimental model for low level laser therapy on ischemic random skin flap in rats

PURPOSE To develop an experimental model to be used in the study of low level Laser therapy on viability of random skin flap in rats. METHODS The sample was 24 Wistar-EPM rats. The random skin flap measured 10 x 4 cm and a plastic sheet was interposed between the flap and donor site. Group 1 (control) underwent sham irradiation with diode laser (830 nm). Group 2 was submitted to laser irradiation with diode laser (830 nm). The animals were submitted to Laser therapy with 36 J/cm(2) energy density (72 seconds) immediately after the surgery and on the four subsequent days. The probe was usually held in contact with the skin flap surface on a point at 2.5 cm cranial from the flap base. On the seventh postoperative day, the percentage of necrotic area was measured and calculated. RESULTS Group 1 reached an average necrotic area of 48.86%, Group 2 - 23.14%. After the statistic analysis, compared with the control group, Group 2 showed a statistically significant increase in survival area (p<0.001). CONCLUSION The experimental model proved to be reliable to be used in the study of effects of low level laser therapy in random skin flap in rats.

Collagen Changes and Realignment Induced by Low-Level Laser Therapy and Low-Intensity Ultrasound in the Calcaneal Tendon

The treatment of calcaneal tendon injuries requires long‐term rehabilitation. Ultrasound (US) and low‐level laser therapy (LLLT) are the most used and studied physical agents in the treatment of tendon injuries; however, only a few studies examined the effects of the combination of US and LLLT. Therefore, the purpose of this study was to investigate which treatment (the exclusive or combined use of US and LLLT) most effectively contribute to tendon healing.

Effect of Low-Level Laser Therapy on Mast Cells in Viability of the Transverse Rectus Abdominis Musculocutaneous Flap

OBJECTIVE To assess the effect of low-level laser therapy (LLLT) on viability of mast cells of the transverse rectus abdominis musculocutaneous (TRAM) flap. BACKGROUND DATA LLLT has been recently used on the TRAM flap to stimulate mast cells. MATERIALS AND METHODS Eighty-four Wistar rats were randomly divided into seven groups of 12 rats in each: group 1 (sham laser therapy); group 2 received 3 J/cm(2) at one point; group 3 received 3 J/cm(2) at 24 points; group 4 received 72 J/cm(2) at 1 point; group 5 received 6 J/cm(2) at 1 point; group 6 received 6 J/cm(2) at 24 points; and group 7 received 144 J/cm(2) at 1 point. All experimental groups underwent LLLT immediately after TRAM surgery and on the next two following days, for three sessions in total. The percentage of the area of skin flap necrosis was calculated on the fourth postoperative day and two samples of skin were collected from each rat with a 1-cm(2) punch to perform mast cell evaluations with toluidine blue dye. RESULTS Statistically significant differences were found in the percentage of necrosis, and higher values were seen in group 1 than in all other groups. Among groups 3-7 no statistically significant differences were found (p < 0.292). For mast cells, when group 1 was compared to groups 5 (6 J/cm(2) at 1 point) and 7 (144 J/cm(2) at 1 point), it had fewer mast cells. CONCLUSION LLLT at a wavelength of 670 nm was effective at reducing the necrotic area, and we found that it can stimulate mast cells growth to increase vascular perfusion.

Effect of Application Site of Low-Level Laser Therapy in Random Cutaneous Flap Viability in Rats

OBJECTIVE This study aimed to investigate the effect of diode laser (830 nm) irradiation on the viability of ischemic random skin flaps in rats, as well as to determine the most effective site for applying laser radiation to speed healing. BACKGROUND DATA Low-level laser therapy (LLLT) has recently been used to improve the viability of ischemic random skin flaps in rats. MATERIALS AND METHODS Seventy Wistar rats were used and divided into seven groups of 10 rats each: group 1, sham laser treatment; group 2, which received irradiation at 1 point 5 cm from the flaps cranial base; group 3, which received irradiation at 2 points (5 and 7.5 cm from the flaps base); group 4, which received irradiation at 3 points (2.5, 5 and 7.5 cm from the flaps base); group 5, which received irradiation at 1 point 2.5 cm from the flaps base; group 6, which received irradiation at 2 points (2.5 and 5 cm from the flaps base); and group 7, which received irradiation at 1 point 7.5 cm from the flaps base. The animals were subjected to laser therapy at an energy density of 36 J/cm(2) for 72 sec immediately after surgery, and one time on each of the four subsequent days. The percentage of necrotic skin flap area was calculated on the seventh postoperative day using a paper template. RESULTS The results showed that the rats in group 5 had the highest increase in skin flap viability, with a statistically significant difference compared to the other groups. Statistically significant differences were not seen between any of the other groups. CONCLUSION The diode laser was effective in increasing skin flap viability in rats, and laser irradiation of a point 2.5 cm from the cranial base flap was found to be the most effective.

Different Power Settings of LLLT on the Repair of the Calcaneal Tendon

OBJECTIVE The purpose of this study was to evaluate the effect of an 830-nm GaAlAs diode laser operating at output powers of 40, 60, 80, and 100 mW and energy density of 30 J/cm(2) on the repair of partial calcaneal tendon ruptures in rats. METHODS A partial tendon rupture was induced in all animals, which were treated with laser irradiation for 5 consecutive days. Six days after injury, the injured tendons were removed and examined by polarized light microscopy. Collagen fiber organization was evaluated by birefringence measurements, and collagen content was determined by Picrosirius Red staining. RESULTS It was observed that the higher the output power (60-100 mW) the greater the amount of type III collagen (p<0.01). The amount of type I collagen was significantly greater (p=0.05) in the 80 mW group than in the control group (sham stimulation). A non-statistically significant improvement in the realignment of collagen fibers was observed in the irradiated groups. CONCLUSIONS Low-level laser therapy resulted in significantly greater amounts of type III collagen (output powers of 60 mW or more) and type I collagen (output power of 80 mW), however, no significant differences between groups were found in the realignment of collagen fibers.

Effect of low-level laser therapy with output power of 30 mW and 60 mW in the viability of a random skin flap.

OBJECTIVE To assess the effects of low-level laser therapy (LLLT) with output power of 30 and 60 mW in the viability of a random skin flap in rats. BACKGROUND DATA Output power values in LLLT are not well defined. MATERIALS AND METHODS Controlled, single-blind experimental study. Thirty-six animals were randomly distributed into three groups: sham group (SG), 30-mW output power (30G), and 60-mW output power (60G). In both treated groups, a fluency of 3 J/cm(2) was used. Two minutes after elevation of a random-pattern cranially based dorsal flap (4 x 10 cm), laser irradiation was applied and repeated on the first, second, third, and fourth postoperative days. Percentages of flap necrosis were calculated on the seventh postoperative day. Also, four fragments of each flap were collected to allow determination of the percentages of vascular density according to the bidimensional method of the morphometric analysis of blood vessels. Statistical analysis included the Wilcoxon test and Kruskal-Wallis variance analysis. A significance level of 5% was elected (p < 0.05). RESULTS Laser-treated animals presented significantly less necrosis than the sham group (SG, 53%; 30G, 24%; p < 0.05) (60G, 25%; p < 0.05). Also, laser-treated animals presented significantly more vascular density than the sham group (SG, 37%; 30G, 57%; p < 0.05) (60G, 59%; p < 0.05). CONCLUSION LLLT (660 nm) with 30-mW and 60-mW output power was efficient in the increase of skin flap viability, but there was no difference between them.

Effect of Low-Level Laser Therapy on Malondialdehyde Concentration in Random Cutaneous Flap Viability

OBJECTIVE The aim of this study was to assess the effects of 830 and 670 nm laser on malondialdehyde (MDA) concentration in random skin-flap survival. BACKGROUND DATA Low-level laser therapy (LLLT) has been reported to be successful in stimulating the formation of new blood vessels and activating superoxide-dismutase delivery, thus helping the inhibition of free-radical action and consequently reducing necrosis. MATERIALS AND METHODS Thirty Wistar rats were used and divided into three groups, with 10 rats in each one. A random skin flap was raised on the dorsum of each animal. Group 1 was the control group; group 2 received 830 nm laser radiation; and group 3 was submitted to 670 nm laser radiation. The animals underwent laser therapy with 36 J/cm(2) energy density immediately after surgery and on the 4 days subsequent to surgery. The application site of the laser radiation was 1 point, 2.5 cm from the flaps cranial base. The percentage of the skin-flap necrosis area was calculated 7 days postoperative using the paper-template method, and a skin sample was collected immediately after as a way of determining the MDA concentration. RESULTS Statistically significant differences were found between the necrosis percentages, with higher values seen in group 1 compared with groups 2 and 3. Groups 2 and 3 did not present statistically significant differences (p > 0.05). Group 3 had a lower concentration of MDA values compared to the control group (p < 0.05). CONCLUSION LLLT was effective in increasing the random skin-flap viability in rats, and the 670 nm laser was efficient in reducing the MDA concentration.

Mechanical stimulation improves survival in random-pattern skin flaps in rats.

This was a study on the effects of 3-MHz ultrasound at 16- and 100-Hz pulse repetition frequencies on angiogenesis and viability of random-pattern skin flaps in rats. A cranially-based dorsal skin flap was raised in 60 EPM-Wistar rats, which were randomly divided into four groups: control, sham, 16-Hz and 100-Hz groups. The mean percentage of necrosis was as follows: control, 42% ± 13%; sham, 18% ± 13%; 16-Hz group, 13% ± 10%; and 100-Hz group, 15% ± 7%, with significant differences between the control and the other groups (p < 0.001). The mean vascular density was as follows: control, 5% ± 2%; sham, 7% ± 2%; 16-Hz group, 21% ± 4%; and 100-Hz group, 24% ± 10%, with significant differences between control and ultrasound groups, and between the sham and ultrasound groups (p < 0.001). Both ultrasound treatments (16- and 100-Hz PRFs) induced angiogenesis, and sham and ultrasound treatments improved viability of random-pattern skin flaps in rats.

In vitro effect of 470 nm LED (Light Emitting Diode) in keloid fibroblasts

PURPOSE To quantify keloid fibroblasts after irradiation with 470nm blue LED, in vitro. METHODS Fibroblasts from keloid and adjacent skin have been obtained from 6 patients. Cells have been cultivated and maintained in DMEM culture medium. In Petri dishes, they were irradiated with energy doses of 6J, 12J and 18J. After 24 h, counting was done by the average of the triplicates for each sample. RESULTS There were no significant differences in the number of irradiated keloid fibroblasts at the studied doses (p=0.261). In adjacent skin fibroblasts, differences were observed (p=0.025) concerning the doses of 18 J and 6 J (p=0.03). CONCLUSIONS There was a reduction in the number of adjacent skin fibroblasts irradiated with 470nm blue LED at the energy dose of 18 J compared to the ones irradiated at the energy dose of 6 J. There were no changes in keloid fibroblasts counting at any of the doses applied, 24 h after irradiation.