Objective:To analyze the iodine nutrition status of children and adolescents and influencing factors in Zhejiang Province, providing scientific basis for optimizing iodine deficiency disorders (IDD) prevention and control strategies.Methods:In June 2022, a multistage stratified sampling method was used to divide 16 counties (cities, districts, abbreviated as counties) in Zhejiang Province into three categories based on their geographical locations (average distance from the coastline): coastal areas (including Dinghai District, Jiaojiang District, Sanmen County, Cixi City and Lucheng District), sub-coastal areas (including Wuxing District, Haining City, Linping District, Fuyang District and Fenghua District), and inland areas(including Suichang County, Changshan County, Shengzhou City, Jindong District, Dongyang City and Yongjia County). One county was selected from each category, and one township (street) was selected from each county. Two administrative villages (neighborhood committees) were selected from each township (street). Ten households including all children and adolescents aged 6-17 in each household were selected from each administrative village (neighborhood committee). Demographic information and personal dietary characteristics were collected via questionnaires, while household salt and a random urine sample were tested for iodine level. Trend analysis was conducted using a χ 2trend test, and a multivariate logistic stepwise regression model was used to analyze the influencing factors of urinary iodine levels. Results:A total of 755 children and adolescents aged 6-17 were selected, including 387 males (51.26%) and 368 females (48.74%), with an age of (11.24 ± 3.32) years. There were 269 children and adolescents in coastal areas (35.63%) and 409 children and adolescents in urban areas (54.17%). A total of 755 household salt samples were collected, with a median salt iodine concentration of 21.80 mg/kg. These included 263 non-iodized salt samples, 38 unqualified iodized salt samples, and 454 qualified iodized salt samples. The coverage rate of iodized salt was 65.17% (492/755), and the consumption rate of qualified iodized salt was 60.13% (454/755). The distribution of salt iodine quality among children and adolescents in different geographical locations showed statistically significant differences (χ 2 = 111.95, P < 0.001), with the proportion of non-iodized salt gradually decreasing from coastal areas to inland areas (χ 2trend = 90.17, P < 0.001). A total of 755 urine samples were collected, with a median urinary iodine concentration of 186.60 μg/L. The proportions of urinary iodine < 100, 100-199, 200-299, and ≥300 μg/L were 16.95% (128/755), 37.62% (284/755), 24.37% (184/755), and 21.06% (159/755), respectively. The χ 2trend test revealed a nonlinear positive correlation between salt iodine level and urinary iodine level (χ 2regression = 21.98, P < 0.001; χ 2partial = 6.96, P < 0.001). The frequency distribution of urinary iodine in children and adolescents from different geographical locations and between urban and rural areas showed statistically significant differences (χ 2 = 29.63, 16.56, P < 0.001). Among them, the proportion of children and adolescents with urinary iodine < 100 μg/L gradually decreasing from coastal areas to inland areas (χ 2trend = 6.15, P = 0.013). The results of multivariate logistic regression analysis revealed that sub-coastal regions, inland regions, and urban-rural regions ( OR = 1.57, 1.53, 1.64, 95% CI: 1.11-2.24, 1.03-2.27, 1.17-2.32, P < 0.05) were significantly associated with urinary iodine levels in children and adolescents aged 6-17. Conclusions:In 2022, the iodine nutrition of children and adolescents in Zhejiang Province is generally suitable, but there is a risk of iodine deficiency among coastal children and adolescents. Geographic location and urban/rural areas are influencing factors on iodine nutrition status of children and adolescents in Zhejiang Province.

Objective:To investigate the iodine nutrition status of pregnant women in Zhejiang Province, explore the impact of salt industry system reform on iodine nutrition level of pregnant women, and provide scientific basis for prevention and treatment of iodine deficiency disorders.Methods:From 2016 to 2021, a multi-stage stratified sampling method was used to select 100 pregnant women from 90 counties (cities, districts) in Zhejiang Province each year as survey subjects. Salt samples were collected from pregnant women's families, and one random urine sample was taken for salt iodine and urinary iodine level testing, respectively.Results:A total of 56 581 samples of household edible salt were collected from pregnant women, with a median salt iodine level of 23.20 mg/kg. Among them, 7 961 were non iodized salt, 45 803 were qualified iodized salt, and 2 817 were unqualified iodized salt. The iodized salt coverage rate was 85.93% (48 620/56 581), and the qualified iodized salt consumption rate was 80.95% (45 803/56 581). The proportion of non iodized salt increased from 10.05% (897/8 928) in 2016 to 15.09% (1 461/9 679) in 2021 (χ 2trend = 95.16, P < 0.001). A total of 56 581 urine samples were collected from pregnant women, with a median urinary iodine level of 130.50 μg/L. Among them, the proportions of urinary iodine levels < 150, 150 - 249, 250 - 499, and ≥500 μg/L were 58.32% (32 996/56 581), 27.24% (15 410/56 581), 12.24% (6 926/56 581), and 2.21% (1 249/56 581), respectively. The median urinary iodine level of pregnant women in inland areas was significantly higher than that in coastal areas ( Z = 19.15, P < 0.001). Furthermore, urinary iodine levels exhibited a non-linear decline as age increased (χ 2regression = 12.65, P < 0.001; χ 2partial = 22.65, P < 0.001) and as pregnancy progressed (χ 2regression = 37.28, P < 0.001; χ 2partial = 18.89, P < 0.001). Conclusions:The overall iodine nutrition status of pregnant women in Zhejiang Province is in a state of iodine deficiency (< 150 μg/L), and there is a greater risk in coastal areas compared to inland areas. However, in the context of the reform of the salt industry system, it is still necessary to strengthen the quality supervision of iodized salt, provide scientific iodine supplementation education, promote specialized iodized salt for pregnant women, and strengthen interventions for prevention and control of iodine deficiency disorders.

Objective:To analyze the iodine nutrition status and its related factors among adults aged 18 years and above in Zhejiang Province in 2022.Methods:A multistage stratified sampling method was used to select 4 320 adults aged 18 years and above from 16 on-site survey sites in Zhejiang Province for the study. A questionnaire was used to investigate the general demographic information and personal dietary characteristics of the study participants. Household edible salt and urine samples were collected to detect salt iodine content and urinary iodine level by using direct titration and cerium arsenate-catalyzed spectrophotometry, respectively, to evaluate the iodine nutritional status according to the standard. The multiple-ordered logistic regression model was used to analyze the factors influencing the urinary iodine concentration.Results:The age of the 4 320 study participants was (51.19±15.33) years, with males accounting for 44.44% (1 920). About 40.16% of adults (1 735) were from coastal areas and 56.37% (2 435) from urban areas. The salt iodine content, M ( Q1, Q3), of the 4 320 household edible salt samples was 21.10 (0.00, 24.16) mg/kg, including 1 662 non-iodized salt samples, 182 unqualified iodized salt samples and 2 476 qualified iodized salt samples. The rate of iodized salt coverage was 61.53%, and the rate of qualified iodized salt consumption was 57.31%. There was a statistically significant difference in the proportion of qualified iodized salt in adult households among different regions ( P<0.001), with the proportion of non-iodized salt gradually decreasing from coastal to inland areas ( χ 2trend=618.458, P<0.001). The urinary iodine concentration M ( Q1, Q3) was 137.60 (86.85, 210.60) μg/L in 4 320 adult urine samples, with the urinary iodine levels of<100, 100-199, 200-299, and≥300 μg/L accounting for 31.64% (1 367), 40.56% (1 752), 17.66% (763), and 10.14% (438), respectively. There was a nonlinear positive correlation between household salt iodine content and urinary iodine level in adults aged 18 years and above by using the χ 2 test for trend ( χ 2regression=231.10, P<0.001 and χ 2skew=28.81, P<0.001). Urinary iodine concentrations were higher in men than in women ( P=0.029) and higher in adults in rural areas than in urban areas ( P<0.001). There were statistically significant differences in the distribution of iodine nutritional status among adults of different ages, regions, and urban and rural areas (all P<0.001). The proportion of those with urinary iodine levels<100 μg/L gradually increased with age ( χ 2trend=37.493, P<0.001), and gradually decreased from coastal areas to inland areas ( χ 2trend=71.381, P<0.001). The results of the multiple-ordered logistic regression model analysis showed that compared with adults aged 18 to 44 years and male adults, those aged 45 to 59 years and female adults had lower urinary iodine levels, with OR (95% CI) of 0.75 (0.68-0.83) and 0.85 (0.76-0.95), respectively. Compared with adults in coastal and urban adults, those in sub-coastal, inland and rural adults had higher levels of urinary iodine, with OR (95% CI) of 1.89 (1.63-2.19), 2.02 (1.72-2.37) and 1.46 (1.28-1.66), respectively. Conclusion:The overall iodine nutrition level of adults aged 18 years and above in Zhejiang Province in 2022 is generally appropriate. However, there is a potential risk of iodine deficiency among adults in coastal areas.

Objective:To investigate the iodine nutrition status of pregnant women in Zhejiang Province, explore the impact of salt industry system reform on iodine nutrition level of pregnant women, and provide scientific basis for prevention and treatment of iodine deficiency disorders.Methods:From 2016 to 2021, a multi-stage stratified sampling method was used to select 100 pregnant women from 90 counties (cities, districts) in Zhejiang Province each year as survey subjects. Salt samples were collected from pregnant women's families, and one random urine sample was taken for salt iodine and urinary iodine level testing, respectively.Results:A total of 56 581 samples of household edible salt were collected from pregnant women, with a median salt iodine level of 23.20 mg/kg. Among them, 7 961 were non iodized salt, 45 803 were qualified iodized salt, and 2 817 were unqualified iodized salt. The iodized salt coverage rate was 85.93% (48 620/56 581), and the qualified iodized salt consumption rate was 80.95% (45 803/56 581). The proportion of non iodized salt increased from 10.05% (897/8 928) in 2016 to 15.09% (1 461/9 679) in 2021 (χ 2trend = 95.16, P < 0.001). A total of 56 581 urine samples were collected from pregnant women, with a median urinary iodine level of 130.50 μg/L. Among them, the proportions of urinary iodine levels < 150, 150 - 249, 250 - 499, and ≥500 μg/L were 58.32% (32 996/56 581), 27.24% (15 410/56 581), 12.24% (6 926/56 581), and 2.21% (1 249/56 581), respectively. The median urinary iodine level of pregnant women in inland areas was significantly higher than that in coastal areas ( Z = 19.15, P < 0.001). Furthermore, urinary iodine levels exhibited a non-linear decline as age increased (χ 2regression = 12.65, P < 0.001; χ 2partial = 22.65, P < 0.001) and as pregnancy progressed (χ 2regression = 37.28, P < 0.001; χ 2partial = 18.89, P < 0.001). Conclusions:The overall iodine nutrition status of pregnant women in Zhejiang Province is in a state of iodine deficiency (< 150 μg/L), and there is a greater risk in coastal areas compared to inland areas. However, in the context of the reform of the salt industry system, it is still necessary to strengthen the quality supervision of iodized salt, provide scientific iodine supplementation education, promote specialized iodized salt for pregnant women, and strengthen interventions for prevention and control of iodine deficiency disorders.

Objective:To analyze the iodine nutrition status and its related factors among adults aged 18 years and above in Zhejiang Province in 2022.Methods:A multistage stratified sampling method was used to select 4 320 adults aged 18 years and above from 16 on-site survey sites in Zhejiang Province for the study. A questionnaire was used to investigate the general demographic information and personal dietary characteristics of the study participants. Household edible salt and urine samples were collected to detect salt iodine content and urinary iodine level by using direct titration and cerium arsenate-catalyzed spectrophotometry, respectively, to evaluate the iodine nutritional status according to the standard. The multiple-ordered logistic regression model was used to analyze the factors influencing the urinary iodine concentration.Results:The age of the 4 320 study participants was (51.19±15.33) years, with males accounting for 44.44% (1 920). About 40.16% of adults (1 735) were from coastal areas and 56.37% (2 435) from urban areas. The salt iodine content, M ( Q1, Q3), of the 4 320 household edible salt samples was 21.10 (0.00, 24.16) mg/kg, including 1 662 non-iodized salt samples, 182 unqualified iodized salt samples and 2 476 qualified iodized salt samples. The rate of iodized salt coverage was 61.53%, and the rate of qualified iodized salt consumption was 57.31%. There was a statistically significant difference in the proportion of qualified iodized salt in adult households among different regions ( P<0.001), with the proportion of non-iodized salt gradually decreasing from coastal to inland areas ( χ 2trend=618.458, P<0.001). The urinary iodine concentration M ( Q1, Q3) was 137.60 (86.85, 210.60) μg/L in 4 320 adult urine samples, with the urinary iodine levels of<100, 100-199, 200-299, and≥300 μg/L accounting for 31.64% (1 367), 40.56% (1 752), 17.66% (763), and 10.14% (438), respectively. There was a nonlinear positive correlation between household salt iodine content and urinary iodine level in adults aged 18 years and above by using the χ 2 test for trend ( χ 2regression=231.10, P<0.001 and χ 2skew=28.81, P<0.001). Urinary iodine concentrations were higher in men than in women ( P=0.029) and higher in adults in rural areas than in urban areas ( P<0.001). There were statistically significant differences in the distribution of iodine nutritional status among adults of different ages, regions, and urban and rural areas (all P<0.001). The proportion of those with urinary iodine levels<100 μg/L gradually increased with age ( χ 2trend=37.493, P<0.001), and gradually decreased from coastal areas to inland areas ( χ 2trend=71.381, P<0.001). The results of the multiple-ordered logistic regression model analysis showed that compared with adults aged 18 to 44 years and male adults, those aged 45 to 59 years and female adults had lower urinary iodine levels, with OR (95% CI) of 0.75 (0.68-0.83) and 0.85 (0.76-0.95), respectively. Compared with adults in coastal and urban adults, those in sub-coastal, inland and rural adults had higher levels of urinary iodine, with OR (95% CI) of 1.89 (1.63-2.19), 2.02 (1.72-2.37) and 1.46 (1.28-1.66), respectively. Conclusion:The overall iodine nutrition level of adults aged 18 years and above in Zhejiang Province in 2022 is generally appropriate. However, there is a potential risk of iodine deficiency among adults in coastal areas.

Objective:To analyze the iodine nutrition status of children and adolescents and influencing factors in Zhejiang Province, providing scientific basis for optimizing iodine deficiency disorders (IDD) prevention and control strategies.Methods:In June 2022, a multistage stratified sampling method was used to divide 16 counties (cities, districts, abbreviated as counties) in Zhejiang Province into three categories based on their geographical locations (average distance from the coastline): coastal areas (including Dinghai District, Jiaojiang District, Sanmen County, Cixi City and Lucheng District), sub-coastal areas (including Wuxing District, Haining City, Linping District, Fuyang District and Fenghua District), and inland areas(including Suichang County, Changshan County, Shengzhou City, Jindong District, Dongyang City and Yongjia County). One county was selected from each category, and one township (street) was selected from each county. Two administrative villages (neighborhood committees) were selected from each township (street). Ten households including all children and adolescents aged 6-17 in each household were selected from each administrative village (neighborhood committee). Demographic information and personal dietary characteristics were collected via questionnaires, while household salt and a random urine sample were tested for iodine level. Trend analysis was conducted using a χ 2trend test, and a multivariate logistic stepwise regression model was used to analyze the influencing factors of urinary iodine levels. Results:A total of 755 children and adolescents aged 6-17 were selected, including 387 males (51.26%) and 368 females (48.74%), with an age of (11.24 ± 3.32) years. There were 269 children and adolescents in coastal areas (35.63%) and 409 children and adolescents in urban areas (54.17%). A total of 755 household salt samples were collected, with a median salt iodine concentration of 21.80 mg/kg. These included 263 non-iodized salt samples, 38 unqualified iodized salt samples, and 454 qualified iodized salt samples. The coverage rate of iodized salt was 65.17% (492/755), and the consumption rate of qualified iodized salt was 60.13% (454/755). The distribution of salt iodine quality among children and adolescents in different geographical locations showed statistically significant differences (χ 2 = 111.95, P < 0.001), with the proportion of non-iodized salt gradually decreasing from coastal areas to inland areas (χ 2trend = 90.17, P < 0.001). A total of 755 urine samples were collected, with a median urinary iodine concentration of 186.60 μg/L. The proportions of urinary iodine < 100, 100-199, 200-299, and ≥300 μg/L were 16.95% (128/755), 37.62% (284/755), 24.37% (184/755), and 21.06% (159/755), respectively. The χ 2trend test revealed a nonlinear positive correlation between salt iodine level and urinary iodine level (χ 2regression = 21.98, P < 0.001; χ 2partial = 6.96, P < 0.001). The frequency distribution of urinary iodine in children and adolescents from different geographical locations and between urban and rural areas showed statistically significant differences (χ 2 = 29.63, 16.56, P < 0.001). Among them, the proportion of children and adolescents with urinary iodine < 100 μg/L gradually decreasing from coastal areas to inland areas (χ 2trend = 6.15, P = 0.013). The results of multivariate logistic regression analysis revealed that sub-coastal regions, inland regions, and urban-rural regions ( OR = 1.57, 1.53, 1.64, 95% CI: 1.11-2.24, 1.03-2.27, 1.17-2.32, P < 0.05) were significantly associated with urinary iodine levels in children and adolescents aged 6-17. Conclusions:In 2022, the iodine nutrition of children and adolescents in Zhejiang Province is generally suitable, but there is a risk of iodine deficiency among coastal children and adolescents. Geographic location and urban/rural areas are influencing factors on iodine nutrition status of children and adolescents in Zhejiang Province.

【Objective】 To investigate the clinical efficacy and significance of percutaneous cement discoplasty (PCD) in treating elderly patients with spinal instability and vacuum phenomenon on imaging. 【Methods】 We retrospectively analyzed 27 patients with spinal instability and vacuum phenomenon on imaging who underwent PVABC between June 2019 and September 2022. We recorded the surgery duration, bone cement usage, intraoperative bleeding, and total hospitalization time. We evaluated the improvement in pain and lumbar function by comparing pre- and postoperative visual analog scale (VAS) scores, Oswestry Disability Index (ODI) scores, and lumbar Japanese Orthopedic Association (JOA) scores. We also compared the change in intervertebral height and the distribution rate of bone cement in the intervertebral space by pre- and postoperative imaging data. 【Results】 All the 27 patients who underwent PCD had effective follow-up. The mean hospitalization time was (4.2±1.85) days, and the mean surgery duration was (32.3±4.51), (53.6±12.17), (74.4±6.33), and (90.0±10.36) minutes for single-, double-, triple-, and quadruple-level procedures, respectively. The intraoperative bleeding volume ranged from 2 to 13 mL, which was significantly lower than that of traditional intervertebral fusion surgery. Postoperative VAS pain scores, ODI scores, and JOA scores were significantly improved compared to those before surgery. In terms of imaging, the intervertebral height of the patients improved after surgery, and the distribution of bone cement in the intervertebral space was relatively good in the operated segments. Mechanical stability of the spine was restored. 【Conclusion】 For patients who are not suitable for open surgery due to severe complications, PCD is a feasible treatment option.

Objective:To analyze the iodine nutrition status of children aged 8 to 10 years in Zhejiang Province from 2016 to 2021.Methods:A multi-stage stratified sampling method was used to select non-residential children aged 8 to 10 years from 90 counties in Zhejiang Province. A total of 114 103 children were included in the study from 2016 to 2021. Direct titration method and arsenic-cerium catalytic spectrophotometry were used to detect salt iodine content and urinary iodine level, respectively, to evaluate the iodine nutritional status of children. Ultrasound was used to detect thyroid volume and analyze the current prevalence of goiter in school-age children.Results:The age of 114 103 children was (9.04 ± 0.81) years old, with 50.0% of (57 083) boys. The median of iodine content M ( Q1, Q3) in children's household salt was 23.00 (19.80, 25.20) mg/kg, including 17 242 non-iodized salt, 6 173 unqualified iodized salt, and 90 688 qualified iodized salt. The coverage rate of iodized salt was 84.89%, and the coverage rate of qualified iodized salt was 79.48%. The proportion of non-iodized salt increased from 11.85% in 2016 to 16.04% in 2021 ( χ 2trend=111.427, P<0.001). The median of urinary iodine concentration M ( Q1, Q3) in children was 182.50 (121.00, 261.00) μg/L, among which the proportions of iodine deficiency, iodine suitability, iodine over suitability, and iodine excess were 17.25% (19 686 cases), 39.21% (44 745 cases), 26.85% (30 638 cases), and 16.68% (19 034 cases), respectively. The median of urinary iodine concentration in children in inland areas [ M ( Q1, Q3): 190.90 (128.80, 269.00) μg/L] was significantly higher than that in children in coastal areas [ M ( Q1, Q3): 173.00 (113.00, 250.30) μg/L] ( P<0.001). From 2016 to 2021, a total of 39 134 ultrasound examinations were conducted, and 1 229 cases of thyroid enlargement were detected. The goiter rate was 3.14% (95% CI: 2.97%-3.32%). The incidence of goiter in children in coastal areas [3.45% (95% CI: 3.19%-3.72%), 641/18 604] was higher than that in children in inland areas [2.86% (95% CI: 2.64%-3.10%), 588/20 530] ( P=0.001). Conclusion:From 2016 to 2021, the iodine nutrition level of children aged 8-10 years in Zhejiang Province is generally suitable, and the rate of goiter in children meets the limit of iodine deficiency disease elimination standards.

Iodine is an essential nutrient required for thyroid hormone synthesis and human growth and development. Iodine requirements increase substantially during pregnancy, and insufficient iodine intake may affect the health of pregnant women, and fetal growth and development. Iodized salt-based iodine supplementation is effective to improve maternal iodine levels, reduce risk of thyroid dysfunctions, and plays a vital role in improvements of offspring growth and development and prevention of intellectual disability. However, excessive iodine supplementation during pregnancy may affect maternal thyroid functions and the nerve development of offspring. Precise and personalized iodine supplementation schemes are therefore required tailored to local iodine deficiency degree and pregnant women's individual iodine status. This review summarizes the advances in the impact of iodine supplementation during pregnancy on maternal and offspring health, so as to provide insights into the guidance of iodine supplementation during pregnancy.

Objective:To investigate the clinical efficacy and prognosis of simultaneous resection of synchronous colorectal liver metastasis in patients admitted in different phases.Methods:The retrospective cohort study was conducted. The clinicopathological data of 346 patients who underwent simultaneous resection of synchronous colorectal liver metastasis in the First Affiliated Hospital of Naval Medical University (Changhai Hospital of Shanghai) from January 2000 to April 2021 were collected. There were 217 males and 129 females, aged (58±12)years. Patients under-went simultaneous resection of synchronous colorectal liver metastasis. Observation indicators: (1) clinicopathological features of patients with synchronous colorectal liver metastasis in 2000?2010 and 2011?2021; (2) surgical and postoperative situations of patients with synchronous colorectal liver metastasis in 2000?2010 and 2011?2021; (3) analysis of prognosis of patients with synchro-nous colorectal liver metastasis in 2000?2010 and 2011?2021. Follow-up was conducted using telephone interview or outpatient examination to detect survival of patients. The follow-up was performed once every 3 months, including blood routine test, liver and kidney function test, car-cinoembryonic antigen (CEA) test, CA19-9 test, abdominal B-ultrasound examination, and once every 6 months, including chest computed tomography (CT) plain scan, liver magnetic resonance imaging (MRI) and/or CT enhanced scan, abdominal or pelvic MRI and/or CT enhanced scan, within postoperative 2 year. The follow-up was performed once every 6?12 months within postoperative 2?5 years including above reexaminations. Electronic colonoscopy was performed once a year after operation. The follow-up was up to November 12, 2021. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the t test. Measurement data with skewed distuibution were represented as M(range). Count data were described as absolute numbers, and comparison between groups was conducted using the chi-square test. Comparison of ordinal data was conducted using the rank sum test. Kaplan-Meier method was used to calculate survival rates and draw survival curves, and Log-Rank test was used to conduct survival analysis. Results:(1) Clinicopathological features of patients with synchronous colorectal liver metastasis in 2000?2010 and 2011?2021. Of the 346 patients, 59 cases underwent simultaneous resection within 2000?2010 and 287 cases underwent simultaneous resection within 2011?2021. The gender (males and females), cases with or without fundamental diseases, cases with the number of lymph nodes harvested in primary lesion as <12 or ≥12, the tumor diameter of primary lesion, the tumor diameter of liver metastasis lesion, the number of liver metastasis lesions, cases with or without preoperative treatment, cases with or without postoperative treatment, cases with adjuvant therapy as perioperative treatment, surgery or other treatment were 47, 12, 36, 23, 19, 40, (5.5±2.4)cm, (2.1±0.7)cm, 1.6±0.5, 59, 0, 16, 16, 0, 16, 43 in patients admitted in 2000?2010, respectively. The above indicators in patients admitted in 2011?2021 were 170, 117, 121, 166, 58, 229, (4.2±2.0)cm, (3.0±2.0)cm, 1.9±1.4, 208, 79, 34, 235, 74, 29, 184, respectively. There were significant differences in the above indicators between patients admitted in 2000?2010 and 2011?2021 ( χ2=8.73, 7.02, 4.07, t= 4.40, ?6.04, ?3.10, χ2=21.05, 28.82, 26.68, P<0.05). (2) Surgical and postoperative situations of patients with synchronous colorectal liver metastasis in 2000?2010 and 2011?2021. Cases with surgical methods as complete open surgery or laparoscopy combined with open surgery, the operation time, time to postoperative initial liquid food intake, cases with or without postoperative complications, cases with postoperative duration of hospital stay as ≤10 days or >10 days were 58, 1, (281±57)minutes, (5±1)days, 33, 26, 14, 45 in patients admitted in 2000?2010, respec-tively. The above indicators in patients admitted in 2011?2021 were 140, 147, (261±82)minutes, (3±1)days, 233, 54, 198, 89, respectively. There were significant differences in the above indicators between patients admitted in 2000?2010 and 2011?2021 ( χ2=49.04, t=2.24, 7.53, χ2=17.56, 26.02, P<0.05). There was no death in the 346 patients. (3) Analysis of prognosis of patients with synchro-nous colorectal liver metastasis in 2000?2010 and 2011?2021. Of the 346 patients, 295 cases were followed up for 47(range, 1?108)months. Of the 29 patients admitted in 2000?2010 who were followed up, there were 27 cases died. The median survival time, 1-, 3-, 5-year overall survival rates, 1-, 3-, 5-year disease free survival rates of patients admitted in 2000?2010 were 18.0 months (95% confidence interval as 12.7?23.3 months), 82.8%, 11.5%, 3.8%, 53.6%, 8.3%, 4.2%, respec-tively. Of the 266 patients admitted in 2011?2021 who were followed up, there were 109 cases died. The median survival time, 1-, 3-, 5-year overall survival rates, 1-, 3-, 5-year disease free survival rates of patients admitted in 2011?2021 were 54.0 months (95% confidence interval as 38.1?70.4 months), 93.3%, 61.8%, 47.0%, 68.2%, 33.7%, 28.3%, respectively. There were significant differences in overall survival rate and disease free survival rate between patients admitted in 2000?2010 and 2011?2021 ( χ2=47.57, 9.17, P<0.05). Conclusions:With the increase of the operation volume of simultaneous resection of synchronous colorectal liver metastasis, the operation time, time to postoperative initial liquid food intake, postoperative duration of hospital stay and postoperative complications have significantly decreased, while the overall survival rate and disease free survival rate have significantly increased.