[The prevention and therapy of corneal ulcers in patients with large-area thermal burns].

Objective: To evaluate the characteristics of ocular injury in patients with severe extensive thermal burns, and to explore the effective methods to prevent and treat corneal ulcers related to severe burns. Methods: A retrospective case series study. Between 2010 and 2019, Sixteen severe thermal burn patients with burn sizes>70% of the total body surface area involving the ocular region were admitted to the Burns and Plastic Surgery Division of Chinese PLA General Hospital, and consult with Ophthalmology Division. There were deep second-degree to fourth-degree burns in the eyelids. In the eleven surviving patients, 22 eyes presented ectropion. Eyelid full-thickness skin grafting (EFTSG) combined with or without tarsorrhaphy was performed in 20 eyes due to severe corneal exposure. Two eyes received partial blepharorrhaphy because of mild ectropion. The ocular manifestations and treatment outcomes were reviewed and assessed. Results: The majority of the patients were youth, and the average age was (36.8±10.4) years. The burn area was 84.0%±9.1% of the body surface area. Corneal ulcers secondary to lagophthalmos occurred at (35.1±15.6) days after burning in 75% (24/32) of eyes. Perforation was found in 18.8% (6/32) of eyes. Among the 22 operated eyes, the corneal ulcer was repaired in all 9 eyes receiving EFTSG with tarsorrhaphy, whereas ectropion recurred in 8 of 11 eyes only receiving EFTSG, and 4 eyes underwent further surgery due to corneal epithelial defects. Conclusions: In patients with severe large-area thermal burns, corneal ulcers are common complications. Prevention of corneal exposure is vital because the treatment of corneal ulceration is difficult due to eyelid deformity, inflammation and the absence of donor skin. Timely full-thickness skin grafting and blepharorrhaphy are effective approaches to preventing exposure keratopathy. To severe ulcers occur, conjunctival flap or Tenon's capsule covering combined with eyelid EFTSG and tarsorrhaphy is useful to rescue visual function.

[Application of metagenomic next-generation sequencing technology in pathogen detection in patients with burns and patients with acute or chronic wounds].

Objective: To explore the value of using metagenomic next-generation sequencing (mNGS) technology to detect pathogens in patients with burns and patients with acute or chronic wounds. Methods: A retrospective observational study was conducted. From March 2019 to June 2020, 11 patients with burns and patients with acute or chronic wounds (including 10 males and 1 female, aged 23 to 85 years) in the Fourth Medical Center of PLA General Hospital met the inclusion criteria and were recruited. A total of 23 specimens were collected, including 6 whole blood specimens, 1 skin tissue specimen, 1 drained pus specimen, and 15 wound secretion swab specimens. Each specimen was divided into two parts, which were subjected for pathogen detection using microbial culture method and mNGS method, respectively. The number and types of pathogens detected by the 2 methods and the relative abundance detected by the mNGS method were recorded, and the consistency of the two methods were compared. Data were statistically analyzed with paired Wilcoxon rank sum test. Results: With the microbial culture method, no pathogen was detected in 5 of the 23 specimens, while 35 pathogens were detected in the remaining 18 specimens, belonging to 9 species of bacteria and 2 species of fungi. Five specimens had one pathogen while 9 specimens had 2 pathogens and 4 specimens had 3 pathogens detected in each specimen. With the mNGS method, no pathogen was detected in one of the 23 specimens, while 75 pathogens were detected in the remaining 22 specimens, belonging to 28 species of bacteria, 3 species of fungi, and 3 species of viruses. Eight specimens had one pathogen, 5 specimens had 2 pathogens, 2 specimens had 3 pathogens, 3 specimens had 4 pathogens, 2 specimens had 6 pathogens, and 1 specimen had 7 pathogens, and 1 specimen had 20 pathogens detected in each specimen. The number of pathogens detected in each specimen by microbial culture method was 2 (1, 2) types, which was significantly less than 2 (1, 4) types by mNGS method (Z=3.359, P<0.01). In 5 specimens, no bacteria were detected by microbial culture method but mNGS method detected bacteria in 2 specimens and virus in 2 different specimens. The mNGS method detected two or more types of bacteria in 13 specimens, the relative abundance of bacteria with the 1st relative abundance ranking ranged from 28.8% to 95.9% in each specimen. Of the 23 specimens detected by two detection methods, 7 specimens (30.4%) showed identical detection results, 5 specimens (21.7%) showed totally different detection results, and 11 specimens (47.8%) had partially consistent detection results. Conclusions: Compared with the traditional microbial culture method, the mNGS method has higher detection sensitivity and stronger capacity to detect pathogens, and can determine the relative abundance of pathogens in mixed infections. As a supplement to the culture method, the mNGS method is expected to play an important role in the diagnosis of infectious pathogens in burns and acute or chronic wounds.

[Ten cases of wound hemostasis with glove bandaging in hand skin grafting].

From July 2018 to April 2019, 10 patients (8 males and 2 females, aged 5 to 53 years) who need skin grafting with 17 hands were admitted to the Fourth Medical Center of PLA General Hospital. The method of glove bandaging was used for wound hemostasis in skin grafting. After the initial hemostasis, sterile latex gloves were used as the inner cover of hand, and then pressure-wrapped with gauze. After 20 minutes, the gauze and gloves were removed in order from the near to the far, then thorough hemostasis was conducted again, and finally skin grafting was performed. The use of gloves as inner cover can avoid the adhesion of gauze fibers to the wound surface, so that it will not cause small blood vessels to re-bleed when the gauze is removed, therefore reducing the excessive use of electrocoagulation and secondary damage to the wound. As a result, blood loss can be reduced and hemostatic time can be shortened.

[Clinical effects and mechanism of treating extensive deep burns by stage-â ¡ Meek skin grafting on adipose tissue after tangential excision].

Objective: To observe the clinical effects of stage-Ⅱ Meek skin grafting on adipose tissue after tangential excision in patients with extensive deep burns, and to explore the functional mechanism. Methods: The medical records of 26 extensively burned patients who met the inclusion criteria and were admitted to the Department of Burns and Plastic Surgery of the Fourth Medical Center of PLA General Hospital from May 2015 to December 2017 were retrospectively analyzed. According to the treatment methods, 14 patients were enrolled in stage-Ⅰ skin grafting group (10 males and 4 females, aged 27 to 75 years), and 12 patients were enrolled in stage-Ⅱ skin grafting group (10 males and 2 females, aged 31 to 76 years). Patients in the 2 groups all underwent debridement of tangential excision, and their healthy adipose tissue was preserved. Meek skin grafting was performed just after tangential excision in patients in stage-Ⅰ skin grafting group. In patients in stage-Ⅱ skin grafting group, porcine acellular dermal matrix (ADM) was applied to cover the wound after tangential excision, and 3 days later, it was removed and Meek skin grafting was performed. The times of complement skin grafting and the wound basic healing time of patients in the 2 groups were observed and recorded. In the stage-Ⅱ skin grafting group, the adipose tissue of patients were taken from the wound center immediately after tangential excision and immediately after the removal of porcine ADM, for the observation of structure of the fault surface of adipose tissue through hematoxylin and eosin staining and microvessel density (MVD) through immunohistochemical staining. Data were processed with independent sample t test and Fisher's exact probability test. Results: (1) The times of complement skin grafting of patients in stage-Ⅱ skin grafting group was (1.83±0.17) times, which was obviously less than (3.36±0.63) times in stage-Ⅰ skin grafting group (t=2.19, P<0.05). The wound basic healing time of patients in stage-Ⅱ skin grafting group was (35.1±2.3) d, which was obviously shorter than (48.8±4.9) d in stage-Ⅰ skin grafting group (t=2.27, P<0.05). (2) Immediately after tangential excision, the intercellular substance was few between the adipose cells in adipose tissue of patients in stage-Ⅱ skin grafting group. Immediately after the removal of porcine ADM, there was regenerated granulation tissue in the intercellular space of adipose cells of adipose tissue of patients in stage-Ⅱ skin grafting group. Immediately after tangential excision, the MVD of adipose tissue of patients in stage-Ⅱ skin grafting group was 20.2±1.3 under per 400-time field, which was obviously less than 32.2±1.9 under per 400-time field immediately after the removal of porcine ADM (t=-5.38, P<0.01). Conclusions: Meek skin grafting on the adipose tissue in stage-Ⅱ surgery after tangential excision could reduce the times of complement skin grafting and shorten wound healing time of patients with extensive deep burns. The mechanism may be related to the improvement of the recipient condition of adipose tissue.

[Effects of minimally invasive tangential excision in treating deep partial-thickness burn wounds on trunk and limbs in pediatric patients in the early stage post burn].

Objective: To observe the effects of minimally invasive tangential excision in treating deep partial-thickness burn wounds on trunk and limbs in pediatric patients in the early stage post burn. Methods: Clinical data of 40 children with deep partial-thickness burn wounds on trunk and limbs, admitted to our burn ward from January 2016 to June 2017, conforming to the study criteria, were retrospectively analyzed. They were divided into conventional treatment group (CT, n=19) and minimally invasive tangential excision group (MITE, n=21) according to the different treatments. The patients in group CT were treated with eschar-reserving therapy firstly. When tangential excision was performed, the roller knife was used, and no necrotic tissue left on the wound bed was considered the proper depth of excision. Razor-thickness skin grafting was performed to cover the wound when adipose tissue exposed markedly after tangential excision. Dressing change was performed within 48 h after the operation and repeated every 2 days. Unhealed wounds were covered by razor-thickness skin grafting. The patients in group MITE were treated with tangential excision in the early stage post burn. The tangential excision was operated with electric dermatome, and the thickness was set at 0.1 mm to excise the surface of eschar until the sporadic punctate hemorrhage on wound surface was observed and some necrotic tissue was left on the wound bed. Porcine acellular dermal matrix was applied after tangential excision. The first dressing change was often performed about 1 week after the operation. Razor-thickness skin grafting was performed to cover the unhealed wounds. The length of wound healing, high fever, antibiotic usage, and hospital stay, times of later operation, and hospitalization expenses of patients in the 2 groups were recorded. The excisional eschar and wound bed tissue of patients in group MITE were harvested for pathological observation. Data were processed with t test and Fisher's exact probability test. Results: (1) There were no statistically significant differences in length of high fever and length of hospital stay and hospitalization expenses between patients in the 2 groups (t=-1.67, -1.93, 0.31, P>0.05). The lengths of wound healing [(24.8±2.5) d] and antibiotic usage [(4.4±0.7) d] of patients in group MITE were significantly shorter than those in group CT [(33.3±2.5) and (7.0±0.7) d, t=-2.44, -2.44, P<0.05], and times of later operation of patients in group MITE [(0.29±0.14) times] were significantly less than those in group CT [(0.79±0.21) times, t=-2.03, P<0.05]. (2) The thickness of the excisional eschar of patients in group MITE was about 150 µm. The eschar has epidermis and upper dermis. Some necrotic tissue was left on the wound bed. Conclusions: The treatment for pediatric deep partial-thickness burn wounds on trunk and limbs with minimally invasive tangential excision using electric dermatome in the early stage post burn can accelerate wound healing, shorten length of antibiotic usage, and reduce times of later operations.

[Effect of mitochondrial apoptosis on pulmonary fibrosis in rats with severe scald injury].

OBJECTIVE: To explore the role of mitochondrial apoptosis on pulmonary fibrosis in rats with severe scald injury. METHODS: According to the random digital table, a total number of 32 Wistar rats were divided into 4 groups: sham burn (group A), burn group (group B), 12-week post burn recovery group (group C), and 12-week post burn recovery plus a second burn injury group (group D). In group A and group B, lung tissues were harvested on post burn day 4. After received first burn injury 12 weeks, the group C and group D received separately a second sham burn injury and burn injury. Lung tissues were harvested on post burn day 4 after the second burn injury. All tissues were examined for cells apoptosis by Terminal-deoxynucleoitidyl Transferase Mediated Nick End Labeling (TUNEL). Pulmonary fibrosis was assessed by Masson trichrome staining and Sirius red staining. The protein expression levels of cleaved Caspase-3, Bax and Bcl-2 were assessed by Western blot. RESULTS: Both Masson trichrome staining and Sirius red staining showed obvious pulmonary fibrosis in group C and group D. The apoptosis rates of group B, C and D were significantly higher than that in group A ((15.50±3.30)%, (7.88±3.10)%, (15.88±3.23)% vs (2.10±1.07)%, all P<0.05). Compared to group A, cleaved Caspase-3 levels were significantly higher in group B, C and D ((0.59±0.11), (0.33±0.08), (0.73±0.13) vs (0.16±0.05), all P<0.05). The ratio of Bax/Bcl-2 in group B, C and D also increased significantly ((2.08±0.30), (0.83±0.09), (1.54±0.12) vs (0.64±0.05), all P<0.05). CONCLUSION: Severe burn injury can induce pulmonary fibrosis and mitochondrial apoptosis may play an important role in the development of pulmonary fibrosis.