Objective:To screen the optimal machine learning model for predicting the recurrence condition of hepatocellular carcinoma (HCC) at different time points post-surgery, based on the cutoff value of the Ki67 positive proliferation index condition calculated from recurrence-free survival and combined with various clinical features.Methods:retrospective study included initially treated patients with solitary HCC who underwent radical surgery at the Fifth Medical Center of the PLA General Hospital from January 2013 to March 2023. Data included general clinical data, preoperative laboratory parameters, and surgical pathology information about the subjects. The postoperative recurrence status was assessed by querying the medical record system or by telephone follow-up. The Ki67 positive index cutoff value was determined by the X-tile software based on the patient's recurrence-free survival status and time analysis. Survival rates were calculated using the Kaplan-Meier method, and survival curves were plotted. The study population was randomly divided into training and testing groups in a 7:3 ratio using a computer-generated random number method. The minimum redundancy maximum relevance (mRMR) method was used for feature variable selection. Predictive models for postoperative HCC recurrence conditions in patients with HCC were constructed using random forest, support vector machine, logistic regression, and gradient boosting decision tree machine learning algorithms. Inter-group comparisons for continuous data were performed using the t-test or Mann-Whitney U test. Inter-group comparisons of enumeration data were performed using the Pearson χ2 test, continuity-corrected χ2 test, or Fisher's exact test. Results:The cutoff values for the Ki67 positivity index were 0.3 and 0.5 in 510 cases, with a follow-up time ranging from 1.2 to 11.4 years (median: 6.2 years). The recurrence-free survival time was between 1 and 135 months (median: 32 months), with recurrence-free survival rates post-surgery at 1, 2, 3, and 5 years were 87.5%, 77.1%, 61.2%, and 54.5%, respectively. The top five variables predicted HCC recurrence and non-recurrence conditions following surgical follow-up at 6 months, 1 year, 2 years, and beyond 2 years, in accordance with information obtained by the mRMR screen out. The Ki67 positivity index screened a successfully constructed machine learning model to predict HCC recurrence and non-recurrence conditions following surgical follow-up at 6 months, 1 year, 2 years, and beyond 2 years. The machine learning model based on the gradient boosting decision tree algorithm had the best prediction performance among them (areas under the receiver operating characteristic curves for predicting HCC recurrence within six months in the training and validation sets were 0.996 and 0.946, and accuracies were 0.972 and 0.935, respectively).Conclusion:A machine learning model was successfully constructed using the Ki67 positivity index combined with four readily available clinical features to predict HCC recurrence. The machine learning model based on the gradient boosting decision tree algorithm demonstrated the best performance in terms of predicting HCC recurrence within six months after surgery.

Objective:To construct a failure mode and effects analysis(FMEA)evaluation model for medical devices to manage devices,so as to enhance management efficiency for medical devices.Methods:The FMEA was adopted to construct FMEA evaluation model for medical devices,so as to conduct comprehensive lifecycle management for medical devices.The process of management for equipment was optimized,and the operational risk of medical devices was reduced through failure mode(FM)analysis and the construction of management system for equipment.A total of 47 medical devices in clinical use of The First People's Hospital of Neijiang from January to December 2023 were included.In them,23 devices received conventional management mode during January and June 2023,and 24 devices received FMEA evaluation model(model management mode)during July and December 2023.For each group,2,000 patients'medical records were selected.The control effectiveness of infectious indicators,effect of cleaning and disinfection,and quality scores of infectious control for medical devices were compared between different management modes.A self-designed questionnaire was adopted to investigate the recognition scores of engineers who used and managed devices,operators,physicians,and department administrators for two kinds of management modes.Results:In 2,000 patients'medical records,who adopted model management mode,the infection rate of patients,and infection rate of aseptic surgical incision were respectively 0.15%and 0.05%,both were significantly lower than those in the conventional management mode(x2=5.420,8.358,P<0.05).The cleaning rate,and disinfection qualification rate of 24 medical devices,which adopted model management mode,were respectively 83.33%and 87.50%,all of which were significantly higher than these of conventional management mode(x2=8.080,6.741,P<0.05).The scores of standardized operation,rational use,disinfection and cleaning,and emergency intervention for medical devices in adopting model management mode were significantly higher than those in adopting conventional management mode(t=14.435,16.014,13.049,12.537,P<0.05).The recognition scores of engineers who used and managed devices,operators,physicians,and department administrators for adopting model management mode were significantly higher than those for adopting conventional management mode,and the differences were significant(t=12.219,12.147,17.437,13.420,P<0.05).Conclusion:The FMEA evaluation model for medical devices can real-time monitor the entire management process for medical devices,and reduce clinical infections,and ensure normal operation of devices,and improve clinically operational quality of them,and increase satisfaction of staffs in clinical departments.

Objective:To investigate the differences in prognosis between different surgical approaches in elderly patients with advanced ovarian cancer.Methods:Based on the Surveillance, Epidemiology and End Results (SEER) database, a cohort of elderly patients with advanced ovarian cancer from 2000 to 2020 was established. Through propensity score matching, 2 094 patients were selected from those who underwent two different surgical approaches to form a matched cohort (SEER database cohort), including 1 039 patients who received cytoreductive surgery and 1 055 patients who underwent local resection. Meanwhile, 148 elderly patients with advanced ovarian cancer who were treated at the First Affiliated Hospital of Shandong First Medical University from January 2012 to January 2024 were selected (hospital cohort), among whom 85 underwent cytoreductive surgery and 63 underwent local resection. The prognostic differences among patients who underwent cytoreductive surgery and local resection in two cohorts and stratified by the International Federation of Gynecology and Obstetrics (FIGO) staging were evaluated, respectively. The relationship between the causes of death and surgical approaches in elderly patients with advanced ovarian cancer was analyzed.Results:In the SEER database cohort, the median overall survival (OS) for patients who underwent cytoreductive surgery and local resection was 37 and 40 months, respectively, with 5-year OS rates of 31.47% and 33.74%, with no statistically significant difference ( χ2=0.78, P=0.378). After stratification by FIGO staging, the median OS for patients with stage ⅢB-ⅢC who underwent cytoreductive surgery ( n=998) and local resection ( n=962) was 38 and 40 months, respectively, with no statistically significant difference ( χ2=0.20, P=0.659). For patients with stage Ⅳ, the median OS for those who underwent cytoreductive surgery ( n=41) and local resection ( n=93) was 17 and 36 months, respectively, with a statistically significant difference ( χ2=9.37, P=0.002). Among 2 094 elderly patients with advanced ovarian cancer, 1 581 had clearly identified causes of death. In patients who underwent cytoreductive surgery, the proportions of deaths due to ovarian cancer and non-ovarian cancer were 94.52% (742/785) and 5.48% (43/785), respectively. In patients who underwent local resection, the proportions of deaths due to ovarian cancer and non-ovarian cancer were 91.46% (728/796) and 8.54% (68/796), respectively. There was a statistically significant difference in the distribution of causes of death between the two surgical approaches ( χ2=5.69, P=0.017). In the hospital cohort, the median OS for patients undergoing cytoreductive surgery and local resection was 39 and 51 months, respectively, with 5-year OS rates of 22.85% and 23.81%, with a statistically significant difference ( χ2=6.71, P=0.010). After stratification by FIGO staging, the median OS for patients with stage ⅢB-ⅢC undergoing cytoreductive surgery ( n=29) and local resection ( n=26) was 50 and 51 months, respectively, with no statistically significant difference ( χ2=0.15, P=0.699) ; for patients with stage Ⅳ undergoing cytoreductive surgery ( n=56) and local resection ( n=37), the median OS was 35 and 47 months, respectively, with a statistically significant difference ( χ2=6.55, P=0.011) . Conclusions:The survival outcomes of local resection in elderly patients with advanced ovarian cancer are not inferior to those of cytoreductive surgery. For FIGO stage Ⅳ patients, the survival period following local resection is superior to that of cytoreductive surgery.

Objective:To investigate the interventional effect of Rhizoma Corydalis on mice with ulcerative colitis(UC)induced by dextran sulfate sodium(DSS),as well as the potential mechanism of Rhizoma Corydalis in the treatment of UC based on metabolomics and inflammation biomarkers.Methods:A mouse model of UC was established,and then the mice were divided into model group,high-dose group(1.517 g/kg crude drug),middle-dose group(0.986 g/kg crude drug),low-dose group(0.455 g/kg crude drug),and positive drug group(5-aminosalicylic acid at a dose of 718.8 mg/kg),while the mice without modeling were selected as normal group(0.9%NaCl by gavage).The mice in each group were administered for 7 consecutive days,and phenotypic parameters were dynamically moni-tored,such as body weight change,disease activity index(DAI),mean daily food intake,and daily water intake.The mice were sacri-ficed after 7 days to collect serum and colon tissue samples;ELISA was used to measure the serum levels of the proinflammatory fac-tors interleukin-6(IL-6),interleukin-17A(IL-17A),C-reactive protein(CRP),and tumor necrosis factor-α(TNF-α),and ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF/MS)was used to perform the non-targeted metabolomics analysis and compare the differences in se-rum metabolite profiles between groups.The mice were selected for modeling and validation with the same method,and glutathione(GSH)was selected as the positive drug.Colon length and mucosal damage were assessed,and quantitative real-time PCR was used to measure the relative mRNA expression levels of the key genes in the glutathione synthesis pathway(γ-glutamylcysteine synthetase[γ-GCS]and oxidative stress regulators yap1p and skn7)and mito-chondrial GSH transporter protein(Slc25a39)in colonic tissue.Results:Rhizoma Corydalis significantly improved weight loss,DAI,and colon length in a dose-dependent manner in the model animals,and there were reductions in the serum levels of IL-6,CRP,and TNF-α,while it had no significant effect on IL-17A.The metabolomics analysis revealed 21 potential biomarkers associated with amino acid and lipid metabolism,which were significantly regulated by Rhizoma Corydalis.In the verification experiment,both Rhi-zoma Corydalis and GSH exerted a significant protective effect against colonic mucosal damage without affecting colon length.Rhizoma Corydalis upregulated the expression of genes associated with glutathione synthesis,especially γ-GCS,suggesting that Rhizoma Co-rydalis could enhance intestinal antioxidant defenses.Conclusion:Rhizoma Corydalis has a therapeutic potential in a mouse model of DSS-induced UC and can alleviate symptoms,reduce the serum levels of inflammatory markers,and regulate metabolic pathways,and upregulation of the genes associated with glutathione synthesis suggests that the drug can enhance intestinal antioxidant defenses.

Objective:To screen the optimal machine learning model for predicting the recurrence condition of hepatocellular carcinoma (HCC) at different time points post-surgery, based on the cutoff value of the Ki67 positive proliferation index condition calculated from recurrence-free survival and combined with various clinical features.Methods:retrospective study included initially treated patients with solitary HCC who underwent radical surgery at the Fifth Medical Center of the PLA General Hospital from January 2013 to March 2023. Data included general clinical data, preoperative laboratory parameters, and surgical pathology information about the subjects. The postoperative recurrence status was assessed by querying the medical record system or by telephone follow-up. The Ki67 positive index cutoff value was determined by the X-tile software based on the patient's recurrence-free survival status and time analysis. Survival rates were calculated using the Kaplan-Meier method, and survival curves were plotted. The study population was randomly divided into training and testing groups in a 7:3 ratio using a computer-generated random number method. The minimum redundancy maximum relevance (mRMR) method was used for feature variable selection. Predictive models for postoperative HCC recurrence conditions in patients with HCC were constructed using random forest, support vector machine, logistic regression, and gradient boosting decision tree machine learning algorithms. Inter-group comparisons for continuous data were performed using the t-test or Mann-Whitney U test. Inter-group comparisons of enumeration data were performed using the Pearson χ2 test, continuity-corrected χ2 test, or Fisher's exact test. Results:The cutoff values for the Ki67 positivity index were 0.3 and 0.5 in 510 cases, with a follow-up time ranging from 1.2 to 11.4 years (median: 6.2 years). The recurrence-free survival time was between 1 and 135 months (median: 32 months), with recurrence-free survival rates post-surgery at 1, 2, 3, and 5 years were 87.5%, 77.1%, 61.2%, and 54.5%, respectively. The top five variables predicted HCC recurrence and non-recurrence conditions following surgical follow-up at 6 months, 1 year, 2 years, and beyond 2 years, in accordance with information obtained by the mRMR screen out. The Ki67 positivity index screened a successfully constructed machine learning model to predict HCC recurrence and non-recurrence conditions following surgical follow-up at 6 months, 1 year, 2 years, and beyond 2 years. The machine learning model based on the gradient boosting decision tree algorithm had the best prediction performance among them (areas under the receiver operating characteristic curves for predicting HCC recurrence within six months in the training and validation sets were 0.996 and 0.946, and accuracies were 0.972 and 0.935, respectively).Conclusion:A machine learning model was successfully constructed using the Ki67 positivity index combined with four readily available clinical features to predict HCC recurrence. The machine learning model based on the gradient boosting decision tree algorithm demonstrated the best performance in terms of predicting HCC recurrence within six months after surgery.

Objective:To construct a failure mode and effects analysis(FMEA)evaluation model for medical devices to manage devices,so as to enhance management efficiency for medical devices.Methods:The FMEA was adopted to construct FMEA evaluation model for medical devices,so as to conduct comprehensive lifecycle management for medical devices.The process of management for equipment was optimized,and the operational risk of medical devices was reduced through failure mode(FM)analysis and the construction of management system for equipment.A total of 47 medical devices in clinical use of The First People's Hospital of Neijiang from January to December 2023 were included.In them,23 devices received conventional management mode during January and June 2023,and 24 devices received FMEA evaluation model(model management mode)during July and December 2023.For each group,2,000 patients'medical records were selected.The control effectiveness of infectious indicators,effect of cleaning and disinfection,and quality scores of infectious control for medical devices were compared between different management modes.A self-designed questionnaire was adopted to investigate the recognition scores of engineers who used and managed devices,operators,physicians,and department administrators for two kinds of management modes.Results:In 2,000 patients'medical records,who adopted model management mode,the infection rate of patients,and infection rate of aseptic surgical incision were respectively 0.15%and 0.05%,both were significantly lower than those in the conventional management mode(x2=5.420,8.358,P<0.05).The cleaning rate,and disinfection qualification rate of 24 medical devices,which adopted model management mode,were respectively 83.33%and 87.50%,all of which were significantly higher than these of conventional management mode(x2=8.080,6.741,P<0.05).The scores of standardized operation,rational use,disinfection and cleaning,and emergency intervention for medical devices in adopting model management mode were significantly higher than those in adopting conventional management mode(t=14.435,16.014,13.049,12.537,P<0.05).The recognition scores of engineers who used and managed devices,operators,physicians,and department administrators for adopting model management mode were significantly higher than those for adopting conventional management mode,and the differences were significant(t=12.219,12.147,17.437,13.420,P<0.05).Conclusion:The FMEA evaluation model for medical devices can real-time monitor the entire management process for medical devices,and reduce clinical infections,and ensure normal operation of devices,and improve clinically operational quality of them,and increase satisfaction of staffs in clinical departments.

Objective:The aim of this study was to explore whether hydroxysafflor yellow A (HSYA) combined with hyaluronidase (HAase) can enhance the therapeutic effect of arterial embolism caused by hyaluronic acid (HA) .Methods:Thirty-two white male rabbits were randomly divided into four groups, with 8 rabbits in each group, of which group A, B and C were experimental groups and group D was group control. An axial rectangular composite tissue flap sized 2.0 cm × 5.0 cm, with 1.0 cm pedicle width, and 4.0 cm from the root, was designed with the central auricular artery as the long axis on the dorsal side of the ear. The depth of incision reached the ventral perichondrium of the ear, and the flap was sutured continuously in situ and divided into three equal parts (area Ⅰ, Ⅱ, Ⅲ) from the proximal area to the distal area. The proximal end 1 cm to the flap and the central artery was the intersection point, into which 50 μl HA was injected, by which the model of HA arterial embolism was established. Each group was treated after 60 min. Group A: 20 ml solution HSYA was injected slowly into the thigh saphenous vein (the dosage of HSYA is calculated at 10 mg/kg) . Group B: 0.5 ml solution HAase was injected into the central auricular artery (400 U/ml) . Group C: 0.5 ml solution HAase with the same dosage of group B was injected into the central auricular artery and 20 ml solution HSYA with the same dosage of group A was injected slowly into the thigh saphenous vein. Group D and other parts of group A and B were injected with the same dosage of normal saline (NS) . The thigh saphenous veins of all groups were injected with the same dosage of solution once a day for 14 days. Flaps were observed immediately, 1, 7 and 14 days after establishment of hyaluronic acid arterial embolism models of tissue flaps, and dorsal and backlight auricular photographs were taken. On the postoperative 14th day, percentages of survival areas of the flaps were calculated, and samples were taken from areas II of tissue flaps, which were stained by hematoxylin-eosin (HE) and Masson, and were detected the activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) . The measurement data conformed to normal distribution was represented as Mean ± SD. Single factor analysis of variance (ANOVA) was used to compare the differences among groups, and head-to-head comparison by LSD test. P <0.05 was considered statistically significant. Results:Tissue flaps of all groups were pale immediately after operation. On the first day after operation, the dark ischemic area appeared at the distal end of each group. On the postoperative 7th day, the ischemic area of each group was necrotic and blackened to varying degrees, and the non-necrotic area swelled obviously. On the postoperative 14th day, the ischemic area of each group was further necrotic, blackened, curled and the boundary was clear. Group C was the best, group D was the worst, and both group A and B were between the two. The swelling of non-necrotic areas in group A and C were basically reduced. HE staining showed that numerous thrombi and inflammatory cells infiltration were formed in group D, and group B was behind it, and thrombi were rare in group A and C. Masson staining showed that collagen fibers were arranged regularly in group C, and abundant collagen fibers were disintegrated and disordered in group D, and both group A and B were between the two. The percentages of survival areas of the flaps in group A, B, C and D were as follows: (69.87 ± 5.04) %, (85.03 ± 6.58) %, (93.93 ± 4.25) % and (49.22±9.64) %. There were statistical differences in pairwise comparison between groups (all P <0.05) . SOD activity of group A, B, C and D were as follows: (49.83±8.08) , (36.65±5.49) , (55.61±7.93) and (22.45 ± 5.47) U/mg prot. Except that group A vs. C, there were statistical differences between groups (all P <0.05) . MDA content of group A, B, C and D were as follows: (0.77±0.17) , (1.03±0.16) , (0.68±0.12) , and (0.41±0.09) nmol/mg prot. Except that group A vs. C, there were statistical differences between groups (all P <0.05) . Conclusions:Under the condition of animal experiment, compared with HAase, HSYA combined with HAase can significantly enhance the therapeutic effect of HA arterial embolism and increase the proportion of survival area of tissue flap.

Objective:To explore the therapeutic effect of hydroxysafflor yellow A (HSYA) combined with hyaluronidase (HAase) for arterial embolism caused by hyaluronic acid (HA).Methods:Thirty-two white male rabbits were randomly divided into four groups, with 8 rabbits in each group. Groups A, B and C were experimental groups, while group D served as the control group. An axial rectangular composite tissue flap sized 2.0 cm × 5.0 cm, with a pedicle width of 1.0 cm, and located 4.0 cm from the root, was designed with the central auricular artery as the long axis on the dorsal side of the ear. The incision depth reached the ventral perichondrium of the ear, and the flap was sutured continuously in place and divided into three equal parts (areas Ⅰ, Ⅱ, Ⅲ) from the proximal to the distal area. The proximal end, located 1 cm from the flap, and the central artery was the intersection point, where 50 μl of HA was injected to establish the model of HA arterial embolism. Each group was treated after 60 minutes. Group A: 20 ml of HSYA solution was slowly injected into the saphenous vein of the thigh (the dosage of HSYA was calculated at 10 mg/kg). Group B: 0.5 ml of HAase solution was injected into the central auricular artery (400 U/ml). Group C: 0.5 ml of HAase solution with the same dosage as in group B was injected into the central auricular artery, while 20 ml of HSYA solution with the same dosage as in group A was slowly injected into the saphenous vein. Group D and other parts of groups A and B were injected with the same dosage of normal saline (NS). The thigh saphenous veins of all groups were injected with the same dosage of solution once daily for 14 days. Flaps were observed immediately, 1, 7 and 14 days after establishing hyaluronic acid arterial embolism models of tissue flaps. Dorsal and backlight auricular photographs were taken. On the 14th day postoperatively, the survival areas of the flaps were calculated. Samples were taken from areas Ⅱof tissue flaps, stained with hematoxylin-eosin (HE) and Masson, to detected the activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA). The measurement data that conformed to a normal distribution was represented as Mean ± SD. Single-factor analysis of variance (ANOVA) was used to compare the differences among groups, followed by head-to-head comparison using the LSD test. P<0.05 was considered statistically significant. Results:Tissue flaps from all groups appeared pale immediately after the operation. On the first day after the operation, a dark ischemic area appeared at the distal end of each group. On the 7th day postoperatively, the ischemic area of each group showed varying degrees of necrosis and blackening, while the non-necrotic area exhibited significant swelling. On the 14th day post-operation, the ischemic area in each group showed further necrosis, blackening, and curling, with clear boundaries. Group C was the best, group D was the worst, and both group A and B were in between the two. The swelling of non-necrotic areas in groups A and C was reduced. HE staining revealed numerous thrombi and infiltration of inflammatory cells in group D, with group B following closely behind. Thrombi were rare in groups A and C. Masson staining showed that collagen fibers were organized regularly in group C, while abundant collagen fibers were disintegrated and disordered in group D. Groups A and B exhibited characteristics that fell between the other two groups. The percentages of survival areas of the flaps in groups A, B, C and D were as follows: (69.87±5.04)%, (85.03±6.58)%, (93.93±4.25)% and (49.22±9.64)%. There were statistical differences in pairwise comparisons between groups (all P<0.05). SOD activity of groups A, B, C, and D were as follows: (49.83±8.08), (36.65±5.49), (55.61±7.93) and (22.45±5.47) U/mg prot. Except for the group A vs. C, there were statistical differences between the groups (all P<0.01). The MDA content of groups A, B, C and D were as follows: (0.77±0.17), (1.03±0.16), (0.68±0.12), and (0.41±0.09) nmol/mg prot. Except that group A vs. C, there were statistical differences between groups (all P<0.01). Conclusion:In animal experiments, it was found that compared to HAase alone, the combination of HSYA with HAase significantly improves the therapeutic outcomes of HA arterial embolism and increases the proportion of tissue flap survival area.

BACKGROUND:Overactive osteoclasts disrupt bone homeostasis and play a bad role in the pathological mechanisms of related skeletal diseases,such as osteoporosis,fragility fractures,and osteoarthritis.Studies have confirmed that ellagic acid and ellagtannin have the potential to inhibit osteoclast differentiation.As their natural metabolites,urolithin A has antioxidant,anti-inflammatory,anti-proliferative and anti-cancer effects,but its effect on osteoclast differentiation and its underlying molecular mechanisms remain unclear. OBJECTIVE:To explore the effect of urolithin A on osteoclast differentiation induced by receptor activator for nuclear factor-κB ligand and its mechanism. METHODS:Mouse mononuclear macrophage leukemia cells(RAW264.7)that grew stably were cultured in vitro.Toxicity of urolithin A(0,0.1,0.5,1.5,2.5 μmol/L)to RAW264.7 cells were detected by cytotoxic MTS assay to screen out the safe concentration.Different concentrations of urolithin A were used again to intervene with receptor activator for nuclear factor-κB ligand-induced differentiation of RAW264.7 cells in vitro.Then,tartrate-resistant acid phosphatase staining and F-actin ring and nucleus staining were performed to observe its effect on the formation and function of osteoclasts.Finally,the expressions of urolithin A on upstream and downstream genes and proteins in the MAPK signaling pathway were observed by western blot and RT-qPCR assays. RESULTS AND CONCLUSION:Urolithin A inhibited osteoclast differentiation and F-actin ring formation in a concentration-dependent manner and 2.5 μmol/L had the strongest inhibitory effect.Urolithin A inhibited the mRNA expression of Nfatc1,Ctsk,Mmp9 and Atp6v0d2 and the protein synthesis of Nfatc1 and Ctsk,related to osteoclast formation and bone resorption.Urolithin A inhibited the activity of osteoclasts by downregulating the phosphorylation of p38 protein to inhibit the mitogen-activated protein kinase signaling pathway.

Objective:The aim of this study was to explore whether hydroxysafflor yellow A (HSYA) combined with hyaluronidase (HAase) can enhance the therapeutic effect of arterial embolism caused by hyaluronic acid (HA) .Methods:Thirty-two white male rabbits were randomly divided into four groups, with 8 rabbits in each group, of which group A, B and C were experimental groups and group D was group control. An axial rectangular composite tissue flap sized 2.0 cm × 5.0 cm, with 1.0 cm pedicle width, and 4.0 cm from the root, was designed with the central auricular artery as the long axis on the dorsal side of the ear. The depth of incision reached the ventral perichondrium of the ear, and the flap was sutured continuously in situ and divided into three equal parts (area Ⅰ, Ⅱ, Ⅲ) from the proximal area to the distal area. The proximal end 1 cm to the flap and the central artery was the intersection point, into which 50 μl HA was injected, by which the model of HA arterial embolism was established. Each group was treated after 60 min. Group A: 20 ml solution HSYA was injected slowly into the thigh saphenous vein (the dosage of HSYA is calculated at 10 mg/kg) . Group B: 0.5 ml solution HAase was injected into the central auricular artery (400 U/ml) . Group C: 0.5 ml solution HAase with the same dosage of group B was injected into the central auricular artery and 20 ml solution HSYA with the same dosage of group A was injected slowly into the thigh saphenous vein. Group D and other parts of group A and B were injected with the same dosage of normal saline (NS) . The thigh saphenous veins of all groups were injected with the same dosage of solution once a day for 14 days. Flaps were observed immediately, 1, 7 and 14 days after establishment of hyaluronic acid arterial embolism models of tissue flaps, and dorsal and backlight auricular photographs were taken. On the postoperative 14th day, percentages of survival areas of the flaps were calculated, and samples were taken from areas II of tissue flaps, which were stained by hematoxylin-eosin (HE) and Masson, and were detected the activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) . The measurement data conformed to normal distribution was represented as Mean ± SD. Single factor analysis of variance (ANOVA) was used to compare the differences among groups, and head-to-head comparison by LSD test. P <0.05 was considered statistically significant. Results:Tissue flaps of all groups were pale immediately after operation. On the first day after operation, the dark ischemic area appeared at the distal end of each group. On the postoperative 7th day, the ischemic area of each group was necrotic and blackened to varying degrees, and the non-necrotic area swelled obviously. On the postoperative 14th day, the ischemic area of each group was further necrotic, blackened, curled and the boundary was clear. Group C was the best, group D was the worst, and both group A and B were between the two. The swelling of non-necrotic areas in group A and C were basically reduced. HE staining showed that numerous thrombi and inflammatory cells infiltration were formed in group D, and group B was behind it, and thrombi were rare in group A and C. Masson staining showed that collagen fibers were arranged regularly in group C, and abundant collagen fibers were disintegrated and disordered in group D, and both group A and B were between the two. The percentages of survival areas of the flaps in group A, B, C and D were as follows: (69.87 ± 5.04) %, (85.03 ± 6.58) %, (93.93 ± 4.25) % and (49.22±9.64) %. There were statistical differences in pairwise comparison between groups (all P <0.05) . SOD activity of group A, B, C and D were as follows: (49.83±8.08) , (36.65±5.49) , (55.61±7.93) and (22.45 ± 5.47) U/mg prot. Except that group A vs. C, there were statistical differences between groups (all P <0.05) . MDA content of group A, B, C and D were as follows: (0.77±0.17) , (1.03±0.16) , (0.68±0.12) , and (0.41±0.09) nmol/mg prot. Except that group A vs. C, there were statistical differences between groups (all P <0.05) . Conclusions:Under the condition of animal experiment, compared with HAase, HSYA combined with HAase can significantly enhance the therapeutic effect of HA arterial embolism and increase the proportion of survival area of tissue flap.