BACKGROUND:Anterior subtotal corpectomy,decompression and fusion is a conventional method to treat cervical degenerative diseases.A titanium cage is an important implant to maintain the stability of the cervical spine after subtotal corpectomy.In recent years,many patients have complications such as titanium cage sinking,which are highly controversial. OBJECTIVE:To investigate the internal biomechanical relationship between the tilt angle of the titanium cage and postoperative titanium cage subsidence after anterior subtotal cervical corpectomy,decompression and fusion. METHODS:A three-dimensional finite element model of the C4-C6 segment was established by CT images of a normal human cervical spine,in which the anterior subtotal resection,decompression and fusion of the C5 vertebral body were simulated,and titanium cages with different tilt angles(-6° to-1° negative angle,that is,the front edge of titanium cage is shorter than the rear edge of titanium cage;1° to 6° positive angle,that is,the front edge of titanium cage is longer than the rear edge of titanium cage)were placed.After setting the boundary conditions,preloads of 50,100 and 150 N were applied respectively on the C4 vertebral body.The stress value of each contact point between the titanium cage and C4 lower-end plate and C6 lower-end plate(seven stress contact points on the contact surface of titanium mesh)was recorded and statistical analysis was conducted. RESULTS AND CONCLUSION:(1)The tilt angles of the titanium cage of the positive angle group and negative angle group under 50,100 and 150 N stress respectively were found by Mann Whitn test,with P<0.05,which was statistically significant.The dispersion coefficients of the positive angle group were smaller than those of the negative angle group under 50,100 and 150 N stress conditions.(2)Under 50,100 and 150 N stress conditions,the Wilcoxon sign rank test in the positive angle group of titanium cage tilt angle found that when the angle was set to 1° to 5°,the difference was not statistically significant(P>0.05).However,when the tilt angle of the titanium cage was set to 6°,the difference was statistically significant(P<0.05).(3)Under 50,100 and 150 N stress conditions,the Wilcoxon sign rank test in the negative angle group of titanium cage tilt angle found that when the tilt angle was set to-1° to-6°,the difference was not statistically significant(P>0.05).(4)It is concluded that in the sagittal position,the titanium cage with a positive tilt angle is more stable than with a negative tilt angle,which is more suitable for clinical use.The tilt angle of the titanium cage is relatively stable in the range of 1° to 5°.When the tilt angle is 6°,the stability starts to decline,which is easy to cause complications of titanium cage sinking after surgery.It is more suitable to select the titanium cage with a tilt angle of 1° to 5° according to the clinical situation during surgery to improve the efficacy.

BACKGROUND:Cervical spondylotic myelopathy is a progressive disease leading to dysfunction in the middle-aged and elderly,and early diagnosis is difficult.In recent years,some clinical scholars have found that dynamic magnetic resonance imaging technology can detect spinal cord compression in a dynamic position earlier,but its specific biomechanical mechanism needs to be clarified. OBJECTIVE:To investigate the biomechanical compression characteristics of early cervical spondylotic myelopathy in hyperextension and flexion position,and to verify the effectiveness of dynamic magnetic resonance imaging in the diagnosis of early cervical spondylotic myelopathy. METHODS:A retrospective analysis was made on the patients who underwent cervical dynamic magnetic resonance imaging in the Department of Orthopedics of First Affiliated Hospital of Guangxi University of Chinese Medicine from January to June 2022.16 subjects were selected and divided into two groups.The pathological group included 8 patients with early cervical spondylotic myelopathy with hypertrophy of ligamentum flavum as the main sign,with 5 male patients and 3 female patients.The normal group included 8 normal degenerative people,with 4 male patients and 4 female patients.All patients were photographed with cervical CT plain scan,magnetic resonance imaging plain scan,and dynamic magnetic resonance imaging plain scan.This study was divided into the following three parts:(1)collect the dynamic magnetic resonance imaging image DCOM data of two groups of subjects,and collect the cervical vertebra CT and neutral magnetic resonance imaging image DCOM data to understand the bone and soft tissue of the two groups of subjects in the neutral position.(2)Based on the DCOM data of magnetic resonance imaging and CT plain scan,the three-dimensional finite element models of lower cervical vertebra(C3-7)of normal degenerative population and early cervical spondylotic myelopathy patients were established by reverse engineering software.The equivalent stress and equivalent elastic strain of the spinal cord and posterior dura were analyzed,and the distribution of stress and strain was observed.(3)After obtaining the stress and strain data,the data between groups were compared to analyze the mechanical characteristics of spinal cord compression caused by early cervical spondylotic myelopathy in a dynamic position and to verify the effectiveness of dynamic magnetic resonance imaging in the diagnosis of early cervical spondylotic myelopathy. RESULTS AND CONCLUSION:(1)When simulating the posterior extension,flexion and neutral position of the lower cervical vertebrae(C3-7)in the two groups,the values of stress and strain in the posterior part of the spinal cord were in the following order:extension>flexion>neutral(P<0.05).The strain values from large to small were as follows:extension>flexion>neutral(P<0.05).(2)Compared with the normal degenerative population model,the equivalent stress and strain of the spinal cord in the pathological group were higher than those in the normal group under two degrees of freedom of flexion and extension(P<0.05).The distribution area of stress and strain in the posterior part of the spinal cord was irregular.(3)In the neutral position,there was no significant difference in the strain value of the spinal cord between the two groups(P>0.05),and the strain distribution was uniform and regular.(4)It is indicated that in the cervical extension position,the dural sac and the posterior part of the spinal cord were compressed and deformed in the early cervical spondylotic myelopathy patients with the hypertrophy of ligamentum flavum as the main sign,and the degree of compression deformation of the spinal cord was significantly higher than that in the anterior flexion position and neutral position.In the neutral position,there were no obvious signs of spinal cord deformation in patients with early cervical spondylotic myelopathy.This study verified the role of dynamic magnetic resonance imaging in the diagnosis of early cervical spondylotic myelopathy from the point of view of biomechanics.

Objective:To investigate the prognosis of patients with initially resectable gastric cancer liver metastasis (GCLM) who were treated by different modalities, and analyze the influencing factors for prognosis of patients.Methods:The retrospective cohort study was conducted. The clinicopathological data of 327 patients with initially resectable GCLM who were included in the database of a nationwide multicenter retrospective cohort study on GCLM based on real-world data from January 2010 to December 2019 were collected. There were 267 males and 60 females, aged 61(54,68)years. According to the specific situations of patients, treatment modalities included radical surgery combined with systemic treatment, palliative surgery combined with systemic treatment, and systemic treatment alone. Observation indicators: (1) clinical characteristics of patients who were treated by different modalities; (2) prognostic outcomes of patients who were treated by different modalities; (3) analysis of influencing factors for prognosis of patients with initially resectable GCLM; (4) screening of potential beneficiaries in patients who were treated by radical surgery plus systemic treatment and patients who were treated by palliative surgery plus systemic treatment. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the independent sample t test. Measurement data with skewed distribution were represented as M( Q1, Q3), and comparison between groups was conducted using the rank sum test. Count data were described as absolute numbers or percentages, and comparison between groups was conducted using the chi-square test. The Kaplan-Meier method was used to calculate survival rate and draw survival curve, and Log-Rank test was used for survival analysis. Univariate and multivariate analyses were conducted using the COX proportional hazard regression model. The propensity score matching was employed by the 1:1 nearest neighbor matching method with a caliper value of 0.1. The forest plots were utilized to evaluate potential benefits of diverse surgical combined with systemic treatments within the population. Results:(1) Clinical characteristics of patients who were treated by different modalities. Of 327 patients, there were 118 cases undergoing radical surgery plus systemic treatment, 164 cases undergoing palliative surgery plus systemic treatment, and 45 cases undergoing systemic treatment alone. There were significant differences in smoking, drinking, site of primary gastric tumor, diameter of primary gastric tumor, site of liver metastasis, and metastatic interval among the three groups of patients ( P<0.05). (2) Prognostic outcomes of patients who were treated by different modalities. The median overall survival time of the 327 pati-ents was 19.9 months (95% confidence interval as 14.9-24.9 months), with 1-, 3-year overall survival rate of 61.3%, 32.7%, respectively. The 1-year overall survival rates of patients undergoing radical surgery plus systemic treatment, palliative surgery plus systemic treatment and systemic treatment alone were 68.3%, 63.1%, 30.6%, and the 3-year overall survival rates were 41.1%, 29.9%, 11.9%, showing a significant difference in overall survival rate among the three groups of patients ( χ2=19.46, P<0.05). Results of further analysis showed that there was a significant difference in overall survival rate between patients undergoing radical surgery plus systemic treatment and patients undergoing systemic treatment alone ( hazard ratio=0.40, 95% confidence interval as 0.26-0.61, P<0.05), between patients undergoing palliative surgery plus systemic treatment and patients under-going systemic treatment alone ( hazard ratio=0.47, 95% confidence interval as 0.32-0.71, P<0.05). (3) Analysis of influencing factors for prognosis of patients with initially resectable GCLM. Results of multivariate analysis showed that the larger primary gastric tumor, poorly differentiated tumor, larger liver metastasis, multiple hepatic metastases were independent risk factors for prognosis of patients with initially resectable GCLM ( hazard ratio=1.20, 1.70, 1.20, 2.06, 95% confidence interval as 1.14-1.27, 1.25-2.31, 1.04-1.42, 1.45-2.92, P<0.05) and immunotherapy or targeted therapy, the treatment modality of radical or palliative surgery plus systemic therapy were independent protective factors for prognosis of patients with initially resectable GCLM ( hazard ratio=0.60, 0.39, 0.46, 95% confidence interval as 0.42-0.87, 0.25-0.60, 0.30-0.70, P<0.05). (4) Screening of potentinal beneficiaries in patients who were treated by radical surgery plus systemic treatment and patients who were treated by palliative surgery plus systemic treatment. Results of forest plots analysis showed that for patients with high-moderate differentiated GCLM and patients with liver metastasis located in the left liver, the overall survival rate of patients undergoing radical surgery plus systemic treatment was better than patients undergoing palliative surgery plus systemic treatment ( hazard ratio=0.21, 0.42, 95% confidence interval as 0.09-0.48, 0.23-0.78, P<0.05). Conclusions:Compared to systemic therapy alone, both radical and palliative surgery plus systemic therapy can improve the pro-gnosis of patients with initially resectable GCLM. The larger primary gastric tumor, poorly differen-tiated tumor, larger liver metastasis, multiple hepatic metastases are independent risk factors for prognosis of patients with initial resectable GCLM and immunotherapy or targeted therapy, the treatment modality of radical or palliative surgery plus systemic therapy are independent protective factors for prognosis of patients with initially resectable GCLM.

Objective:To examine the impact of varied surgical treatment strategies on the prognosis of patients with initial resectable gastric cancer liver metastases (IR-GCLM).Methods:This is a retrospective cohort study. Employing a retrospective cohort design, the study selected clinicopathological data from the national multi-center retrospective cohort study database, focusing on 282 patients with IR-GCLM who underwent surgical intervention between January 2010 and December 2019. There were 231 males and 51 males, aging ( M(IQR)) 61 (14) years (range: 27 to 80 years). These patients were stratified into radical and palliative treatment groups based on treatment decisions. Survival curves were generated using the Kaplan-Meier method and distinctions in survival rates were assessed using the Log-rank test. The Cox risk regression model evaluated HR for various factors, controlling for confounders through multivariate analysis to comprehensively evaluate the influence of surgery on the prognosis of IR-GCLM patients. A restricted cubic spline Cox proportional hazard model assessed and delineated intricate associations between measured variables and prognosis. At the same time, the X-tile served as an auxiliary tool to identify critical thresholds in the survival analysis for IR-GCLM patients. Subgroup analysis was then conducted to identify potential beneficiary populations in different surgical treatments. Results:(1) The radical group comprised 118 patients, all undergoing R0 resection or local physical therapy of primary and metastatic lesions. The palliative group comprised 164 patients, with 52 cases undergoing palliative resections for gastric primary tumors and liver metastases, 56 cases undergoing radical resections for gastric primary tumors only, 45 cases undergoing palliative resections for gastric primary tumors, and 11 cases receiving palliative treatments for liver metastases. A statistically significant distinction was observed between the groups regarding the site and the number of liver metastases (both P<0.05). (2) The median overall survival (OS) of the 282 patients was 22.7 months (95% CI: 17.8 to 27.6 months), with 1-year and 3-year OS rates were 65.4% and 35.6%, respectively. The 1-year OS rates for patients in the radical surgical group and palliative surgical group were 68.3% and 63.1%, while the corresponding 3-year OS rates were 42.2% and 29.9%, respectively. A comparison of OS between the two groups showed no statistically significant difference ( P=0.254). Further analysis indicated that patients undergoing palliative gastric cancer resection alone had a significantly worse prognosis compared to other surgical options ( HR=1.98, 95% CI: 1.21 to 3.24, P=0.006). (3) The size of the primary gastric tumor significantly influenced the patients′ prognosis ( HR=2.01, 95% CI: 1.45 to 2.79, P<0.01), with HR showing a progressively increasing trend as tumor size increased. (4) Subgroup analysis indicates that radical treatment may be more effective compared to palliative treatment in the following specific cases: well/moderately differentiated tumors ( HR=2.84, 95% CI 1.49 to 5.41, P=0.001), and patients with liver metastases located in the left lobe of the liver ( HR=2.06, 95% CI 1.19 to 3.57, P=0.010). Conclusions:In patients with IR-GCLM, radical surgery did not produce a significant improvement in the overall prognosis compared to palliative surgery. However, within specific patient subgroups (well/moderately differentiated tumors, and patients with liver metastases located in the left lobe of the liver), radical treatment can significantly improve prognosis compared to palliative approaches.

Objective To study the cognitive protective effect and optimal dose of dexmedetomidine hydrochloride (DEX) in patients with severe depression treated with modified electroconvulsive therapy (MECT).Methods A total of 120 patients with severe depression in our hospital from June 2021 to Decem-ber 2022 were randomly divided into DEX group (D1,D2,D3 group) and control group,with 30 cases in each group.DEX 0.2,0.4,and 0.6 μg/kg were intravenously pumped 10 min before anesthesia in groups D1,D2, and D3,respectively,and the same volume of normal saline was pumped in the control group.The heart rate (HR),mean arterial pressure (MAP),spontaneous breathing recovery time,recovery time,mini-mental state examination (MMSE) score at T0,one d and three d after operation,and adverse reactions were compared a-mong the four groups before anesthesia (T0),10 min after infusion of DEX (T1),after anesthesia induction and loss of consciousness (T2),at the end of MECT (T3),and five min after MECT (T4).Results At T1 and T2,HR in group D1 and HR and MAP in groups D2 and D3 were lower than those at T0,and the differences were statistically significant (P<0.05).At T3,the HR and MAP of the four groups reached the peak,but at T4,the HR and MAP gradually decreased.At T4,the HR and MAP of the control group were higher than those at T0,and the HR and MAP of the D2 and D3 groups were lower than those at T0,the differences were statistically significant (P<0.05).The recovery time of spontaneous breathing in D1,D2 and D3 groups was shorter than that in the control group,and the dosage of propofol was lower than that in the control group,the differences were statistically significant (P<0.05).The recovery time from long to short was D3,D2 and D1 group,and the difference was statistically significant (P<0.05).At one d and three d after operation,the MMSE scores of D1,D2 and D3 groups were higher than those of the control group,and the MMSE score of D3 group was the highest,the difference was statistically significant (P<0.05).Conclusion DEX can reduce MECT stress response and postoperative adverse reactions in patients with severe depression in a dose-de-pendent manner,and protect cognitive function.

Objective:To examine the impact of varied surgical treatment strategies on the prognosis of patients with initial resectable gastric cancer liver metastases (IR-GCLM).Methods:This is a retrospective cohort study. Employing a retrospective cohort design, the study selected clinicopathological data from the national multi-center retrospective cohort study database, focusing on 282 patients with IR-GCLM who underwent surgical intervention between January 2010 and December 2019. There were 231 males and 51 males, aging ( M(IQR)) 61 (14) years (range: 27 to 80 years). These patients were stratified into radical and palliative treatment groups based on treatment decisions. Survival curves were generated using the Kaplan-Meier method and distinctions in survival rates were assessed using the Log-rank test. The Cox risk regression model evaluated HR for various factors, controlling for confounders through multivariate analysis to comprehensively evaluate the influence of surgery on the prognosis of IR-GCLM patients. A restricted cubic spline Cox proportional hazard model assessed and delineated intricate associations between measured variables and prognosis. At the same time, the X-tile served as an auxiliary tool to identify critical thresholds in the survival analysis for IR-GCLM patients. Subgroup analysis was then conducted to identify potential beneficiary populations in different surgical treatments. Results:(1) The radical group comprised 118 patients, all undergoing R0 resection or local physical therapy of primary and metastatic lesions. The palliative group comprised 164 patients, with 52 cases undergoing palliative resections for gastric primary tumors and liver metastases, 56 cases undergoing radical resections for gastric primary tumors only, 45 cases undergoing palliative resections for gastric primary tumors, and 11 cases receiving palliative treatments for liver metastases. A statistically significant distinction was observed between the groups regarding the site and the number of liver metastases (both P<0.05). (2) The median overall survival (OS) of the 282 patients was 22.7 months (95% CI: 17.8 to 27.6 months), with 1-year and 3-year OS rates were 65.4% and 35.6%, respectively. The 1-year OS rates for patients in the radical surgical group and palliative surgical group were 68.3% and 63.1%, while the corresponding 3-year OS rates were 42.2% and 29.9%, respectively. A comparison of OS between the two groups showed no statistically significant difference ( P=0.254). Further analysis indicated that patients undergoing palliative gastric cancer resection alone had a significantly worse prognosis compared to other surgical options ( HR=1.98, 95% CI: 1.21 to 3.24, P=0.006). (3) The size of the primary gastric tumor significantly influenced the patients′ prognosis ( HR=2.01, 95% CI: 1.45 to 2.79, P<0.01), with HR showing a progressively increasing trend as tumor size increased. (4) Subgroup analysis indicates that radical treatment may be more effective compared to palliative treatment in the following specific cases: well/moderately differentiated tumors ( HR=2.84, 95% CI 1.49 to 5.41, P=0.001), and patients with liver metastases located in the left lobe of the liver ( HR=2.06, 95% CI 1.19 to 3.57, P=0.010). Conclusions:In patients with IR-GCLM, radical surgery did not produce a significant improvement in the overall prognosis compared to palliative surgery. However, within specific patient subgroups (well/moderately differentiated tumors, and patients with liver metastases located in the left lobe of the liver), radical treatment can significantly improve prognosis compared to palliative approaches.

Objective:To identify characteristic genes of rheumatoid arthritis(RA)by artificial neural network and to analyze role of immune cells in RA related microenvironment.Methods:GSE1919 and GSE77298 chips were from GEO database.Two chips were combined and batch corrected using R language to obtain a new data set,and difference was analyzed.Metascape enrichment analysis and GO and KEGG enrichment analysis were conducted for differential expressed genes(DEGs)."randomForest"package in R software was used to screen characteristic genes of RA under random forest(RF)algorithm,and artificial neural network model was constructed according to gene score.Top 4 genes(HubGene)were extracted for subsequent analysis.Single sample gene set enrich-ment analysis(ssGSEA)was used to calculate abundance of immune cells in samples and carry out a series of correlation analysis.Results:Top 15 genes were selected as characteristic genes of RA through artificial neural network model:STAT1,RUNX3,AR,CDH11,LMO4,TIMP1,PLXNC1,CAP2,PRKAA2,VDR,SPP1,HCK,EPHB2,KCNAB1,ITGB7.STAT1,RUNX3 and CDH11 were up-regulated in RA synovial tissue,while AR was down-regulated in RA synovial tissue.Immune cell infiltration results showed that RA had the most significant correlation with activated CD4 T cells.Number of immune cells significantly related to RUNX3 was the largest.RUNX3 was significant positive correlated with activated B cells,activated CD4 T cells,activated CD8 T cells,central memory CD4+T cells,effector memory CD8 T cells,regulatory T cells,γδT cells and macrophages,while significant negative correlated with NK cells.Conclusion:Fifteen characteristic genes related to RA are identified through artificial neural net-work,among which STAT1,RUNX3,AR and CDH11 are top 4 genes.It emphasizes activation of CD4 T cells,regulatory T cells,γδT cells,macrophages,NK cells,activated B cells and other immune cells are important in pathogenesis of RA,providing new in-sights for diagnosis of RA and study of molecular mechanism of immune cells.

Background Mitochondrial dynamin-related protein 1 (DRP1) regulates mitochondrial division and plays an important role in maintaining hepatocyte function. However, the role of DRP1 in cadmium exposure-induced maternal liver damage in pregnant mice remains unclear. Objective To investigate the role and mechanism of DRP1 in maternal liver damage induced by cadmium exposure during pregnancy. Methods This study consisted of animal experiments and cell experiments. (1) Animal experiments. Mice at 14 days of gestation were randomly divided into three groups: a control group, a low-dose cadmium group (LCd group: 2.5 mg·kg⁻¹), and a high-dose cadmium group (HCd group: 5 mg·kg⁻¹). The pregnant mice were intraperitoneally injected with cadmium chloride (CdCl₂) for 6 and 24 h in the next morning. The weights of pregnant mice, uterus, maternal liver, and fetal mice were recorded after sacrifice. Serum and liver of pregnant mice were collected, the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum were detected, and liver tissues were stained with HE to observe changes in liver function and liver tissue structure. The expressions of oxidative phosphorylation-related proteins, hypoxia inducible factor-1α (HIF-1α) and DRP1 proteins in liver of pregnant mice were detected by Western blotting. (2) Cell experiments. AML12 cells were treated with CdCl₂ (10 μmol·L⁻¹) for 0, 2, 6, 12, and 24 h. The expressions of oxidative phosphorylation-related proteins, DRP1, and hypoxia inducible factor-1α (HIF-1α) proteins were detected. AML12 cells were pretreated with DRP1 inhibitor Mdivi-1 for 1 h and then CdCl₂ (10 μmol·L⁻¹) for 12 h to detect the expression of oxidative phosphorylation-related proteins and DRP1 protein. AML12 cells were treated with Hif-1α siRNA for 48 h and CdCl₂ (10 μmol·L⁻¹) for 6 h to detect the expression of HIF-1α and DRP1 proteins. Results The results of animal experiments showed that cadmium exposure in pregnant mice had no effects on maternal liver weight and liver coefficient. However, the histomorphological changes and necrosis in hepatocytes were observed. Compared with the control group, the serum ALT and AST levels of pregnant mice in the LCd group were significantly increased after 6 h (P＜0.05), and the levels in the HCd group were significantly increased after 6 and 24 h (P＜0.05). Cadmium exposure during pregnancy significantly up-regulated HIF-1α and DRP1 expressions and down-regulated the expressions of oxidative phosphorylation-related proteins in maternal livers. In vitro cell experiments showed that the expressions of oxidative phosphorylation-related proteins was significantly decreased and HIF-1α and DRP1 protein expressions were significantly increased in the AML12 cells treated with CdCl₂ for 6 h. Mdivi-1 pretreatment significantly antagonized the inhibitory effect of cadmium on the expressions of oxidative phosphorylation-related proteins in AML12 cells, while Hif-1α siRNA pretreatment significantly antagonized the up-regulative effect of cadmium on DRP1 expression in AML12 cells. Conclusion Cadmium exposure in pregnant mice may up-regulate DRP1 expression by activating HIF-1α signaling, then inhibit oxidative phosphorylation level of hepatic cells, and ultimately lead to maternal liver damage.

Objective:To investigate the construction and application value of a predictive model for prolonged surgical duration in Da Vinci robotic radical gastrectomy for gastric cancer.Methods:The retrospective cohort study was conducted. The clinicopathological data of 534 patients who underwent Da Vinci robotic radical gastrectomy for gastric cancer in the Fujian Medical University Union Hospital from August 2016 to August 2021 were collected. There were 389 males and 145 females, aged (60±11)years. All 534 patients were randomly divided into the training dataset of 374 cases and the validation dataset of 160 cases with a ratio of 7∶3 based on random number method in the SPSS 25.0 software. Observation indicators: (1) incidence of prolonged surgical duration; (2) intraoperative and postoperative conditions in patients with prolonged surgical duration and without prolonged surgical duration; (3) complications in patients with prolonged surgical duration and without prolonged surgical duration; (4) analysis of risk factors influencing prolonged surgical duration; (5) construction and evaluation of an artificial neural network predictive model for pro-longed surgical duration. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the independent sample t test. Measurement data with skewed distribution were represented as M( Q1, Q3), and comparison between groups was conducted using the Mann-Whitney U test. Count data were described as absolute numbers or per-centages, and comparison between groups was conducted using the chi-square test or Fisher exact probability. Comparison of ordinal data was analyzed using the nonparametric test. Univariate and multivariate analyses were conducted using the Logistic regression model. Based on the results of univariate analysis, a multilayer perceptron was employed to train an artificial neural network pre-dictive model for prolonged surgical duration. The receiver operating characteristic (ROC) curve was drawn, and the area under curve (AUC), the accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were used to assess the model′s performance. Results:(1) Incidence of prolonged surgical duration. Of 534 patients, 284 cases underwent total gastrectomy, and 250 cases underwent distal gastrectomy, with operation time of (206±42)minutes and (187±36)minutes, res-pectively. Cases with prolonged surgical duration and without prolonged surgical duration who under-went total gastrectomy were 41 and 243, and cases with prolonged surgical duration and without prolonged surgical duration who underwent distal gastrectomy were 40 and 210. The gender (male, female), age, body mass index (BMI), tumor diameter, tumor location (upper stomach, middle stomach, lower stomach, mixed type), cases with neoadjuvant therapy, cases with preoperative American Society of Anesthesiologists (ASA) score as 1, 2, 3, cases with clinical T staging as stage T1, stage T2, stage T3, stage T4a, cases with clinical N staging as stage N0, stage N1, stage N2, stage N3, cases with clinical TNM staging as stage Ⅰ, stage Ⅱ, stage Ⅲ, cases with surgical resection scope as total gastrec-tomy or distal gastrectomy, cases with digestive tract reconstruction method as Billroth-Ⅰ anasto-mosis, Billroth-Ⅱ anastomosis, Roux-en-Y anastomosis, cases with surgeon experiences as ≤20 cases or >20 cases were 61,20, (61±9)years, (24±3)kg/m2, 4.0(2.5, 5.0)cm, 34, 10, 33, 4, 1, 3, 73, 5, 3, 6, 26, 46, 14, 41, 19, 7, 5, 13, 63, 41, 40, 1, 33, 47, 5, 76 in the 81 patients with prolonged surgical duration, versus 328, 125, (60±11)years, (23±3)kg/m2, 3.5(2.0, 5.0)cm, 129, 71, 227, 26, 6, 45, 382, 26, 73, 100, 118, 162, 211, 180, 52, 10, 138, 108,207, 243, 210, 13,200, 240, 15, 438 in the 453 patients without prolonged surgical duration, showing significant differences in the BMI, clinical T staging, clinical N staging, clinical TNM staging ( t=-3.68, Z=-4.63, -5.53, -5.56, P<0.05), and no significant difference in the gender, age, tumor diameter, tumor location, preoperative ASA score, surgical resec-tion scope, digestive tract reconstruction method, and surgeon experiences ( χ2=0.29, t=-0.95, Z=-1.27, χ2=5.92, Z=-1.46, χ2=0.25, 1.35, 0.87, P>0.05). There was no significant difference in cases with neoadjuvant therapy between them ( P>0.05). (2) Intraoperative and postoperative conditions in patients with prolonged surgical duration and without prolonged surgical duration. The operation time, volume of intraoperative blood loss, the number of lymph nodes dissected, time to postopera-tive first ambulation, time to postoperative anal exhaust, time to postoperative first intake of liquid diet, time to postoperative first intake of semi-liquid diet, duration of postoperative hospital stay were (261±34)minutes, 50(30, 50)mL, 39±15, (2.3±0.6)days, (3.4±0.9)days, (4.1±1.2)days, (5.7±1.2)days, 8.0(7.0, 9.0)days in the 81 patients with prolonged surgical duration, versus (186±29)minutes, 30(20,50)mL, 42±14, (2.2±0.6)days, (3.4±0.8)days, (4.1±1.1)days, (5.7±1.4)days, 8.0(7.0, 9.0)days in the 453 patients without prolonged surgical duration, showing significant differences in operation time, volume of intraoperative blood loss ( t=-20.46, Z=-3.32, P<0.05), and no significant difference in the number of lymph nodes dissected, time to postoperative first ambulation, time to postopera-tive anal exhaust, time to postoperative first intake of liquid diet, time to first intake of semi-liquid diet, duration of postoperative hospital stay ( t=1.87, -0.87, -0.16, 0.28, 0.03, Z=-1.45, P>0.05). (3) Complications in patients with prolonged surgical duration and without prolonged surgical duration. The overall incidence of complications, incidence of surgical complications (abdominal infection, anastomotic fistula, abdominal bleeding, incision-related complications, intestinal obstruction, lymphatic fistula), incidence of medical complications (pulmonary infection, liver-related complications) were 22.22%(18/81), 0, 0, 2.47%(2/81), 0, 8.64%(7/81), 1.23%(1/81), 12.35%(10/81), 1.23%(1/81) in the 81 patients with prolonged surgical duration, versus 13.47%(61/453), 2.65%(12/453), 0.44%(2/453), 1.77%(8/453), 0.44%(2/453), 3.31%(15/453), 0, 7.28%(33/453), 1.55%(7/453) in the 453 patients without prolonged surgical duration, showing a significant difference in the overall incidence of complications ( χ2=4.18, P<0.05), and no significant difference in the incidence of abdo-minal infection, anastomotic fistula, abdominal bleeding, incision-related complications, intestinal obstruction, lymphatic fistula, liver-related complications ( P>0.05). There was no significant difference in the incidence of pulmonary infection between them ( χ2=2.38, P>0.05). (4) Analysis of risk factors influencing prolonged surgical duration. Results of univariate analysis showed that BMI ≥25 kg/m2, tumor located in the lower stomach, clinical T3-T4a stage, clinical N1-N3 stage were correlated factors influencing prolonged surgical duration in Da Vinci robotic radical gastrectomy for gastric cancer ( odds ratio=1.88, 0.40, 6.24, 6.51, 3.08, 3.39, 17.15, 95% confidence interval as 1.03-3.42, 0.21-0.76, 1.40-27.76, 1.50-28.30, 1.43-6.60, 1.29-8.92, 4.84-60.74, P<0.05). Results of multivariate analysis showed that BMI ≥25 kg/m2, clinical T3 stage, clinical N3 stage were independent risk factors influencing prolonged surgical duration in Da Vinci robotic radical gastrectomy for gastric cancer ( odds ratio=2.31, 4.97, 11.08, 95% confidence interval as 1.19-4.46, 1.05-23.55, 2.72-45.13, P<0.05). (5) Construction and evaluation of an artificial neural network predictive model for pro-longed surgical duration. The BMI, tumor location, clinical T staging, and clinical N staging were incorporated into a multilayer perceptron to construct an artificial neural network predictive model for prolonged surgical duration. Results of ROC curve showed that the AUC, accuracy, sensitivity, specificity, positive predictive value, negative predictive value of the predictive model in the training dataset were 0.73 (95% confidence interval as 0.68-0.78), 91.4%, 68.1%, 94.8%, 65.3%, 95.4%. The above indicators of the predictive model in the validation dataset 0.72 (95% confidence interval as 0.65-0.79), 88.1%, 67.6%, 93.7%, 74.2%, 91.5%. Conclusions:BMI ≥25 kg/m2, clinical T3 stage, clinical N3 stage are independent risk factors influencing prolonged surgical duration in Da Vinci robotic radical gastrectomy for gastric cancer. The artificial neural network predictive model con-structed based on BMI, tumor location, clinical T staging, and clinical N staging can effectively predict patients at high risk of prolonged surgical duration in Da Vinci robotic radical gastrectomy for gastric cancer.

Objective:To investigate the clinical efficacy of Later-cut overlap anastomosis versus Roux-en-Y anastomosis in laparoscopic total gastrectomy.Methods:The propensity score matching and retrospective cohort study was conducted. The clinicopathological data of 1 804 patients with gastric cancer who underwent laparoscopic total gastrectomy in Fujian Medical University Union Hospital from January 2014 to March 2019 were collected. There were 1 346 males and 458 females, aged from 18 to 91 years, with a median age of 63 years. Of 1 804 patients, 100 undergoing Later-cut overlap anastomosis for digestive tract reconstruction in totally laparoscopic total gastrectomy and 1 704 undergoing Roux-en-Y anastomosis in laparoscopic-assisted total gastrectomy were allocated into modified group and traditional group, respectively. Observation indicators: (1) the propensity score matching conditions and comparison of general data between the two groups after propensity score matching; (2) intraoperative and postoperative situations; (3) complications; (4) follow-up, including ① functional scales of European Organization for Research and Treatment of Cancer quality of life questionnaire-core 30 (EORTC-QLQ-C30) for two groups after propensity score matching, ② symptom scales of EORTC-QLQ-C30 for two groups after propensity score matching, ③ symptom scales of European Organization for Research and Treatment of Cancer quality of life questionnaire of stomach 22 (EORTC-QLQ-STO22) for two groups after propensity score matching, ④ subgroup analysis; (5) learning curve of Later-cut overlap anastomosis. Patients were followed up by outpatient examination, paying a visit, Email and telephone interview once every 3 months within postoperative 2 years and once every 6 months within postoperative 3-5 years to detect postoperative life quality up to December 2019. The propensity score matching was conducted by 1∶1 matching using the nearest neighbor method. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was done using the t test. Count data were represented as absolute numbers or percentages, and comparison between groups was analyzed using the chi-square test. Comparison of ordinal data between groups was analyzed using the nonparametric rank sum test. Measurement data with skewed distribution were represented as M ( P25, P75) or M (range), and comparison between groups was done using the U test. The cumulative sum curve was used to analysis minor changes between individual and overall data, with the equation of CUSUM=∑ n,i=1 ( x i- μ), x i as esophagojejunostomy time of individuals, μ as the average time of esophagojejunostomy, n as serial number of patients. Results:(1) The propensity score matching conditions and comparison of general data between the two groups after propensity score matching: 200 of 1 804 patients had successful matching, including 100 in the modified group and 100 in the traditional group respectively. Before propensity score matching, the gender (males or females), age, tumor diameter, cases with tumor located at upper, middle or total stomach (tumor location), cases with differentiated or undifferentiated tumor (tumor differentiation degree), level of preoperative Alb, cases in stage T1, T2, T3, T4a (T staging), cases in stage N0, N1, N2, N3 (N staging), cases in stage Ⅰ, Ⅱ, Ⅲ (Union International Control Cancer staging) were 62, 38, (55±13)years, 4.5 cm(1.5 cm, 7.5 cm), 22, 67, 11, 72, 28, (42±4)g/L, 36, 11, 39, 14, 58, 16, 8, 18, 44, 29, 27 of the modified group, versus 1 284, 420, (62±11)years, 6.5 cm(2.5 cm, 8.0 cm), 891, 675, 138, 1 392, 312, (39±7)g/L, 148, 200, 393, 963, 498, 517, 257, 432, 322, 604, 778 of the traditional group, showing significant differences in the above indicators between the two groups ( χ2=8.89, t=5.69, Z=2.75, χ2=35.31, 5.80, t=3.91, Z=-9.97, -5.44, -5.41, P<0.05). After propensity score matching, the above indicators were 62, 38, (55±13)years, 4.0 cm(1.5 cm, 7.5 cm), 22, 67, 11, 82, 18, (42±4)g/L, 36, 11, 39, 14, 58, 16, 8, 18, 44, 29, 27 of the modified group, versus 68, 32, (56±11)years, 4.0 cm(1.5 cm, 7.4 cm), 12, 74, 14, 87, 13, (41±5)g/L, 23, 18, 45, 14, 54, 18, 10, 18, 42, 40, 18 of the traditional group, showing no significant difference in the above indicators between the two groups ( χ2=0.79, t=0.30, Z=0.87, χ2=3.65, 0.95, t=1.49, Z=-0.94, 1.43, -0.50, P>0.05). (2) Intraoperative and postoperative situations: after propensity score matching, the operation time, volume of intraoperative blood loss, the number of lymph node dissected, time to the first flatus, time to fluid diet intake, duration of postoperative hospital stay, treatment expenses were (195±41)minutes, 72 mL(range, 5-125 mL), 44±15, (3.4±1.1)days, (4.1±1.3)days, (10.7±4.3)days, (74 299±20 102)yuan of the modified group, versus (192±78)minutes, 67 mL(range, 10-195 mL), 40±18, (3.7±1.2)days, (4.5±1.9)days, (14.0±9.2)days, (71 029±12 231)yuan of the the traditional group, respectively. There was no significant difference in the operation time, the number of lymph node dissected, time to the first flatus, time to fluid diet intake, or treatment expenses between the two groups ( t=0.35, 1.73, 1.84, 1.74, 1.38, P>0.05). There were significant differences in the volume of intraoperative blood loss and duration of postoperative hospital stay between the two groups ( Z=0.62, t=3.25, P<0.05). (3) Complications: three patients in the modified group had complications, including 2 cases of anastomotic leakage and 1 case of abdominal infection. Four patients in the traditional group had complications, including 2 cases of anastomotic leakage, 1 case of anastomotic hemorrhage, 1 case of abdominal infection. There was no significant difference in the complications between the two groups ( χ2=0.00, P>0.05). Patients with anastomotic leakage and abdominal infection were cured after conservative treatments including adequate drainage, nutritional support, anti-inflammation. Patients with anastomotic hemorrhage were cured after blood transfusion and hemostatic therapy. There was no perioperative death in either group. (4) Follow-up: 146 patients received life quality evaluation at postoperative 6 months, including 78 in the modified group and 68 in the traditional group. ① Functional scales of EORTC-QLQ-C30 for two groups after propensity score matching: the scores of overall health functioning, physical functioning, role functioning, cognitive functioning, emotional functioning, social functioning were 31(22, 48), 75±27, 77±21, 79±15, 80±21, 76±29 for the modified group, respectively, versus 38(22, 57), 77±30, 79±27, 82±30, 82±31, 78±30 for the traditional group, showing no significant difference between the two groups ( Z=0.46, t=0.39, 0.40, 0.66, 0.49, P>0.05). ② Symptom scales of EORTC-QLQ-C30 for two groups after propensity score matching: the scores of fatigue, nausea and vomiting, pain, dyspnea, hyposomnia, anorexia, constipation, diarrhea, financial difficulty were 75±22, 89±19, 82±19, 77±19, 90±23, 74±14, 67±27, 74±28, 61±29 for the modified group, respectively, versus 72±28, 88±23, 91±23, 72±19, 88±19, 79±29, 68±28, 72±23, 61±24 for the traditional group; there was no significant difference in the scores of fatigue, nausea and vomiting, dyspnea, hyposomnia, anorexia, constipation, diarrhea or financial difficulty between the two groups ( t=0.70, 0.26, 1.56, 0.49, 0.43, 0.20, 0.43, 0.09, P>0.05), while there was a significant difference in the score of pain ( t=2.48, P<0.05). ③ Symptom scales of EORTC-QLQ-STO22 for two groups after propensity score matching: the scores of dysphagia, chest pain or abdominal pain, gastroesophageal reflux, eating disorder, anxiety, dryness of mouth, taste disorder, appearance disturbance, hair loss were 11(6, 20), 13(4, 22), 9(4, 21), 11(7, 20), 23(11, 34), 24(10, 31), 11(5, 21), 19(11, 35), 11(6, 25) for the modified group, respectively, versus 16 (7, 31), 14 (6, 22), 7(5, 16), 11(6, 20), 22 (13, 29), 28 (12, 33), 9 (5, 17), 20 (10, 25), 13 (5, 23) for the traditional group; there was no significant difference in the scores of chest pain or abdominal pain, gastroesophageal reflux, eating disorder, anxiety, dryness of mouth, taste disorder, appearance disturbance, hair loss between the two groups ( Z=0.41, -0.01, 0.99, -0.03, 0.52, 0.46, -0.20, 0.44, P>0.05), while there was a significant difference in the score of dysphagia ( Z=-2.07, P<0.05). ④ Subgroup analysis: after propensity score matching, cases with no, mild, moderate, severe pain (degree of pain perception) for pain-related items in EORTC-QLQ-C30 were 49, 24, 4, 1 of the modified group, versus 43, 9, 14, 2 of the traditional group, showing a significant difference between the two groups ( Z=-2.519, P<0.05). (5)Learning curve of Later-cut overlap anastomosis. The cumulative sum curve for esophagojejunostomy time of the 100 patients in the modified group showed a inflection point at the 33th patient, so the 1st-33th patients were allocated into learning phase and the 34th-100th patients were allocated into stable phase. The operation time, anastomosis time, volume of intraoperative blood loss, the number of lymph node dissected, time to first flatus, time to postoperative liquid diet intake, duration of hospital stay, treatment expenses for patients in the learning phase were (216±60)minutes, (28±10)minutes, 70 mL(range, 10-204 mL), 41±17, (4.5±0.9)days, (5.0±0.8)days, (11.1±4.3)days, 68 722 yuan(range, 52 312-94 943 yuan), respectively, versus (189±51)minutes, (23±8)minutes, 65 mL(range, 5-200 mL), 43±16, (4.4±1.0)days, (5.3±1.1)days, (10.6±6.8)days, 67 380 yuan(range, 49 289-92 732 yuan) for patients in the stable phase. There were significant differences in the operation time and anastomosis time between the two groups ( t=2.27, 2.87, P<0.05). There was no significant difference in the volume of intraoperative blood loss, the number of lymph node dissected, time to first flatus, time to postoperative liquid diet intake, duration of hospital stay or treatment expenses between the two groups ( Z=0.57, t=0.69, 0.49, 1.39, 0.39, Z=0.69, P>0.05). Conclusion:Later-cut overlap anastomosis is a digestive tract reconstruction method after totally laparoscopic total gastrectomy, which can reduce the volume of intraoperative blood loss, relieve postoperative eating obstruction and pain and improve postoperative life quality of patients.