Optical Parameters And Clinical Efficacy For Ultra-pulse CO₂ Fractional Laser Treatment Of Hypertrophic Scars

Objective1.To investigate the gasification depths and carbonization widths of ultra-pulse CO₂ fractional lasers with various energy levels and various times, and to explore the suitable parameters used to treat scars.2.To investigate the efficacy of ultra-pulse CO₂ fractional lasers combine with halometasone and triclosan cream.3.To investigate the intralesional triamcinolone acetonide sequential CO₂ fractional laser treatment of hypertrophic scars efficacy and safety.Methods1.Fresh abdominal skin was harvested from a pig, and was given single laser treatment with different energy levels（10, 15, 20, 30 m J/cm²） and double laser treatments with the same energy level. After stained with hematoxylin-eosin, the gasification depths and carbonization widths after laser treatment were measured under optical microscope. SPSS 17.0 was used in the statistical analysis, and t test was used to compare the means between different groups.2.23 hypertrophic scar patients were divided into group A and group B, than administered ultra-pulse CO₂ fractional laser or ultra-pulse CO₂ fractional laser combined with halometasone triclosan cream, than judge their efficacy.3.33 hypertrophic scar patients was selected from our hospital for the study, they were divided into group A（to triamcinolone injection group）, group B（injection of triamcinolone acetonide than administered ultra-pulse CO₂ fractional laser combined with halometasone triclosan cream treated group）, group C（ultra-pulse CO₂ laser combined with halometasone triclosan cream treated group）, three groups’ change before and after the treatment were scored by Vancouver scar scale score, and the thickness variety before and after treatment were measured by ultrasound diagnostic.Results1.After single ultra-pulse CO₂ fractional laser treatment with different energy levels（10, 15, 20, 30 m J/cm²）, the gasification depths increased with increasing energy levels（t values between 10 and 20 m J/cm², 10 and 30 m J/cm², 15 and 30 m J/cm², 20 and 30 m J/cm² were 27.68, 124.10, 7.81, 10.70, respectively, p<0.05; correlation analysis, r2=0.985, P<0.01）.2.There was no correlation between the energy level and gasification depth after double laser treatments with the same energy level（r2=0.956, P>0.05）.3.For ultra-pulse CO₂ fractional lasers with a given energy level, the gasification depth after single laser treatment was deeper than double laser treatments（t values between double laser treatments with 10 m J/cm² and single laser treatment with 20 m J/cm², double laser treatments with 15 m J/cm² and single laser treatment with 30 m J/cm² were 5.00 and 10.73, respectively. p<0.05）.4.The carbonization width after single laser treatment with 30 m J/cm² was broader than that after single laser treatment with 15 m J/cm².4. There was no change in carbonization widths after other laser treatments with different energy levels and different times（single: t values between 10 and 15 m J/cm², 10 and 20 m J/cm², 10 and 30 m J/cm², 15 and 20 m J/cm², 20 and 30 m J/cm² were 1.49, 0.78, 0.17, 1.54, 1.16, respectively, p>0.05; double: t values between 10 and 15 m J/cm², 10 and 20 m J/cm², 10 and 30 m J/cm², 15 and 20 m J/cm², 20 and 30 m J/cm² were 0.23, 0.64, 0.59, 1.38, 1.91 and 0.44, respectively. p>0.05）.5.The total effective rate was 44% in group A and 78% in group B; The marked effective rate was 11% and 43% in group B.6.Before and after treatment, the VSS scores of group A were（12 + 1.24）,（8.31 + 1.94）, P<0.01; the thickness of scar were（0.44 + 0.18） cm,（0.28 + 0.12） cm, P<0.01. The VSS scores of group B were（10.63 ± 2.39）,（5.13 ± 2.52）, P <0.01; the thickness of scar were（0.33 ± 0.06） cm,（0.17 ± 0.04） cm, P <0.01. The VSS scores of group C were（10.83 ± 2.15）,（9.83 ± 2.37）, P <0.01; the thickness of scar were（0.38 ± 0.10） cm,（0.30 ± 0.07） cm, P <0.01.7.Group B skin atrophy occurs adverse reaction rate was 46.2% and the remaining two groups, no skin atrophy occurs.Conclusion1.The gasification depths increased with increasing energy levels in single ultra-pulse CO₂ fractional laser treatment, which can facilitate the delivery of drugs into dermis;2.For double ultra-pulse CO₂ fractional laser treatments with low energy, the gasification depths increased with increasing energy levels, but the carbonization widths did not change, which can facilitate the delivery of drug with minimum adverse reactions;3.For double laser treatments with high energy, the gasification depths and carbonization widths did not change with increasing energy levels and did not help to improve the treatment outcomes.4.Ultra-pulse CO₂ fractional laser therapy have a certain effect in treating hypertrophic scars. If it combined with halometasone triclosan cream,the efficacy can be improved.5.After injection of triamcinolone acetonide than administered ultra-pulse CO₂ fractional laser combined with halometasone triclosan cream therapy can reduce the incidence of adverse reactions of skin atrophy, also can make the scar healed in softness, hardness, appearance is more close to normal skin, leaving only some pigmentation, it is worth in the clinical application.