Analysis of Energy and Density in Treating Hypertrophic Scar After Burn in Children with CO2 Dot Matrix Laser.

Objective: To analyze and compare the effect of the combination of energy and density parameters of CO2 dot matrix laser in the hyperplastic stage of pediatric burn. Materials and Methods: A total of 160 pediatric patients with hypertrophic scar after limb burn from 2017 to 2020 were randomly divided into four parameter groups (n = 40). The patients were treated with ablative fraction carbon dioxide laser, once every 10 weeks. During the interval of laser treatment, Compound Heparin Sodium and Allantoin Gel (Contractubex) was applied externally, tid, and elastic cover or elastic bandage is attached to the affected limb. Scoring based on the Vancouver Scar Scale is performed before each laser treatment, The score before the first treatment was the initial score, which was scored by two people separately, and the average score was calculated. Subsequently, the patients were treated four times and scored. The differences between each treatment and the first score of each parameter group were compared. Under the same energy and different treatment density, the scores after each treatment were compared. Under the same density and different energy, the scores after each treatment were compared. The bleeding and pigmentation of each parameter group were compared. Results: The increase of density can show the therapeutic effect earlier than the increase of energy, and 25mj energy and 10% density have better intervention effect. With the course of disease and the progress of treatment, the correlation between intervention effect and parameters tends to weaken. Comparing the number of cases with different scores between each treatment and the first time, the score in the 5% density group was lower than that in the 10% density group, but there was no significant difference between the 25mj and 17.5mj energy levels in the same density group. The intervention effect of the increase of density on scar was better than that of energy, and the increase of energy and density could aggravate the pain. Conclusion: In pediatric burn hypertrophic scars treated by CO2 dot matrix laser in exfoliation mode, the intervention effect of increasing density is better than that of energy. When setting laser treatment parameters, we should give priority to increasing density and adjust energy according to the effect of treatment and the condition of pain, bleeding and color precipitation. In this study, the best combination of parameters is 17.5mj/10%.

Analysis of the therapeutic effect of artificial leather embedding combined with fascial sleeve flap transplantation on chronic wounds of lower limbs with bone and plate exposure.

BACKGROUND: After severe trauma of lower limbs, bone, tendon or plate graft exposure is common. The traditional repair method is to use a variety of skin flap transplantation to cover the exposed part, but the wound often can not heal after operation, or the wound is cracked, ulcer, sinus, bone and steel plate are exposed again after wound healing. The reason for this result is that when the flap is covered, the space around the bone plate is not well closed, forming a dead cavity, blood and exudate accumulation, hematoma formation or infection, and finally the wound ruptures again. In addition, due to the swelling and contracture of the flap after operation, the suture tension between the flap and the receiving area becomes larger, the skin becomes thinner and broken, and then the wound is formed. In order to solve the above problems, we carried out the study of artificial true skin embedding combined with fascial sleeve flap transplantation in the treatment of chronic bone plate exposed wounds of lower limbs. METHODS: In this paper, 11 cases of chronic wounds with bone exposure and skin necrosis after steel plate implantation were selected. First stage is the wound bed preparation including primary wound expansion, removal of necrotic tissue and incision of sinus wall, removal of deep necrotic bone and fibrotic scarred skin on the outer wall of steel plate to normal tissue on the outer edge of the wound, removal of precipitated peptone and purulent fur in the hole, periphery and bone space of the steel plate, and removal of tendon tissue with basal necrosis and disintegration of the wound. After vacuum sealing drainage (VSD) 1-2 weeks, the peritraumatic basal granulation tissue grew well and there was no necrotic tissue in the wound. In the second stage, the exposed bone was covered with artificial dermis, the steel plate hole or the periphery and the basal space were filled, and the exposed steel plate was completely embedded, and then the fascia sleeve flap was transplanted to cover the wound. The sural neurovascular flap was performed in nine cases and the lateral superior malleolar artery perforator flap in two case. RESULTS: The flap survived well in all 11 cases. During the follow-up of 6 months to the removal of the plate, there was no case of rupture, exposure and sinus formation. CONCLUSIONS: Artificial dermal covering combined with fascial sleeve flap transplantation can effectively avoid wound dehiscence or sinus formation caused by foreign body retention, infection and flap contracture. It has good effect in repairing chronic wounds with bone plate exposure after severe trauma of lower limbs.

Exosomal miR-451 from human umbilical cord mesenchymal stem cells attenuates burn-induced acute lung injury.

BACKGROUND: The aim of this study was to investigate the molecular mechanism of human umbilical cord mesenchymal stem cells (MSCs)-derived exosomes (hUCMSC-Exos) in regulating burn-induced acute lung injury (ALI). METHODS: In this study, we initially isolated exosomes from hUCMSCs and identified them by transmission electron microscopy. The expression of the protein markers CD9 and CD63 in the exosomes was determined by western blot analysis. The expression of miR-451 in the hUCMSC-Exos was determined by qRT-PCR. The levels of TNF-α, IL-1ß, and IL-6 in lung tissues and serum as well as the levels of malondialdehyde, myeloperoxidase, superoxide dismutase in lung tissues were detected by ELISA. Hematoxylin-eosin stain was used to observe the morphological changes of lung tissues after burn. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assays were performed to detect apoptosis in lung tissues after burn. The expression of proteins related to the Toll-like receptor 4 (TLR4)/NF-κB signaling pathway in lung tissues after burn was analyzed by western blotting. RESULTS: Our results showed that hUCMSC-Exos successfully decreased TNF-α, IL-1ß, and IL-6 levels in rats after burn, and this reduction was reversed when the miR-451 expression in the hUCMSC-Exo group was inhibited. HUCMSC-Exo-derived miR-451 improves ALI via the TLR4/NF-κB pathway. CONCLUSION: We demonstrated that exosomes derived from hUCMSCs mediate miR-451 to attenuate burn-induced ALI.

Lowering the pivot point of sural neurofasciocutaneous flaps to reconstruct deep electrical burn wounds in the distal foot.

Due to the thinness of the skin and soft tissues in the foot, tendons and bones tend to become exposed and necrotic after injury; therefore, it is difficult to reconstruct foot injuries, especially distally. Reconstruction with free skin flaps is highly risky as it demands technologies and equipment, while patients suffer greatly from the use of cross-leg skin flaps. Sural neurofasciocutaneous flaps are often used for reconstruction of wounds in the lower leg, malleolus, and the proximal end of the foot but are not feasible for wound repair in the distal foot; this is because, with the pivot point of 5-7 cm above the tip of the lateral malleolus, the flaps are not able to cover defects in the distal foot. In this study, we used a sural neurofasciocutaneous flaps with a lowered pivot point for reconstruction of distal foot wounds caused by electrical burns. An ultrasound flow detector and Doppler flow imaging were used to detect the diameter, the perforating point and the blood flow of the lateral retromalleolar perforator. Twelve patients with the perforator diameter greater than 0.6 mm and the peak systolic flow more than 0.15 m/s were included. The pivot point of sural neurofasciocutaneous flaps was lowered to 0-3 cm above the tip of the lateral malleolus and the size of the flaps ranged from 6 cm × 5 cm to 12 cm × 18 cm. Eleven of the 12 flaps survived completely. One flap developed necrosis approximately 1cm at the far point but was managed successfully by daily dressing. We demonstrated that lowering the pivot point of sural neurofasciocutaneous flaps is feasible for reconstruction of distal foot injury with the advantages of reliable blood supply and easy operation. The use of Doppler flow imaging provides useful information for the design of the flaps.

[The clinic application of the bust deep artery and (or) the first dorsal metatarsal artery with reversed dorsalis pedis flap].

OBJECTIVE: To explore the better method of repairing the soft tissue defect of the distal foot. METHODS: The soft tissue defect in the distal foot of six patients were repaired by the distally based dorsum pedis island flap pedicled with the bust deep artery and(or) the first dorsal metatarsal artery. RESULTS: Six patients were repaired in one stage, the biggest defect was 8 cm x 6 cm, all patients were followed-up 1 to 4 years, the function of foot was evidently improved, the patients were all satisfied with the operative results. CONCLUSIONS: The bust deep artery and (or) the first dorsal metatarsal artery, with reliable blood supply, were easily dissected and with good texture. So far this kind of flap is a good choice in repairing the defects of the soft tissue in the distal foot.