Objective:To establish a set of artificial intelligence (AI) verification rules for blood routine analysis.Methods:Blood routine analysis data of 18 474 hospitalized patients from the First Hospital of Jilin University during August 1st to 31st, 2019, were collected as training group for establishment of the AI verification rules,and the corresponding patient age, microscopic examination results, and clinical diagnosis information were collected. 92 laboratory parameters, including blood analysis report parameters, research parameters and alarm information, were used as candidate conditions for AI audit rules; manual verification combining microscopy was considered as standard, marked whether it was passed or blocked. Using decision tree algorithm, AI audit rules are initially established through high-intensity, multi-round and five-fold cross-validation and AI verification rules were optimized by setting important mandatory cases. The performance of AI verification rules was evaluated by comparing the false negative rate, precision rate, recall rate, F1 score, and pass rate with that of the current autoverification rules using Chi-square test. Another cohort of blood routine analysis data of 12 475 hospitalized patients in the First Hospital of Jilin University during November 1sr to 31st, 2023, were collected as validation group for validation of AI verification rules, which underwent simulated verification via the preliminary AI rules, thus performance of AI rules were analyzed by the above indicators. Results:AI verification rules consist of 15 rules and 17 parameters and do distinguish numeric and morphological abnormalities. Compared with auto-verification rules, the true positive rate, the false positive rate, the true negative rate, the false negative rate, the pass rate, the accuracy, the precision rate, the recall rate and F1 score of AI rules in training group were 22.7%, 1.6%, 74.5%, 1.3%, 75.7%, 97.2%, 93.5%, 94.7%, 94.1, respectively.All of them were better than auto-verification rules, and the difference was statistically significant ( P<0.001), and with no important case missed. In validation group, the true positive rate, the false positive rate, the true negative rate, the false negative rate, the pass rate, the accuracy, the precision rate, the recall rate and F1 score were 19.2%, 8.2%, 70.1%, 2.5%, 72.6%, 89.2%, 70.0%, 88.3%, 78.1, respectively, Compared with the auto-verification rules, The false negative rate was lower, the false positive rate and the recall rate were slightly higher, and the difference was statistically significant ( P<0.001). Conclusion:A set of the AI verification rules are established and verified by using decision tree algorithm of machine learning, which can identify, intercept and prompt abnormal results stably, and is moresimple, highly efficient and more accurate in the report of blood analysis test results compared with auto-vefication.

Objective:To investigate the influencing factors of reflux esophagitis after sleeve gastrectomy and its plus procedures.Methods:The retrospective case-control study was conducted. The clinical data of 130 patients who underwent sleeve gastrectomy and its plus procedures (jejunal bypass, duodenal-jejunal bypass) for the treatment of metabolic diseases in the First Affiliated Hospital of Nanjing Medical University from May 2010 to August 2021 were collected. There were 34 males and 96 females, aged (32±8)years, with the body mass index (BMI) as (38±7)kg/m 2. Observation indicators: (1) incidence of reflux esophagitis before and after surgery; (2) clinical manifestations of reflux esophagitis and treatment; (3) influencing factors of reflux esopha-gitis after surgery; (4) follow-up. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was conducted using the t test. Measurement data with skewed distribution were represented as M(range). Count data were described as absolute numbers or percentages, and comparison between groups was conducted using the chi-square test or Fisher exact probability. In univariate analysis, the median value of clinical variable was used for grouping and the chi-square test was used for subsequent analysis. Multivariate analysis was conducted using Logistic stepwise regression model. Results:(1) Incidence of reflux esophagitis before and after surgery. Of 130 patients, there were 5 cases with Los Angeles classification grade A reflux esopha-gitis before the surgery, and there were 35 cases with reflux esophagitis after surgery, including 26 cases as Los Angeles classification grade A esophagitis, 8 cases as Los Angeles classification grade B esophagitis and 1 case as Los Angeles classification grade C esophagitis. There was a significant difference in the incidence of reflux esophagitis for patients before and after surgery ( P<0.05). (2) Clinical manifestations of reflux esophagitis and treatment. The 5 patients with preoperative reflux esophagitis described with no obvious heartburn and acid regurgitation and did not receive treat-ment. For the 35 patients with postoperative reflux esophagitis, 22 cases described with heartburn and acid regurgitation, and 13 cases described without any symptoms. Of the 35 patients, 10 were treated with continuous oral proton pump inhibitors, 2 were treated with intermittent oral proton pump inhibitors, 10 were relieved by dietary adjustment, and 13 were not treated. For the 95 patients without postoperative reflux esophagitis, 5 cases described with heartburn and acid regurgitation, requiring continuous oral proton pump inhibitor treatment. The remaining 90 cases described no heartburn and acid regurgitation and did not receive treatment. (3) Influencing factors of reflux esophagitis after surgery. Results of multivariate analysis showed that the preoperative reflux diagnostic questionnaire scoring >0 and the occurrence of postoperative heartburn and acid regurgi-tation were independent risk factors of postoperative reflux esophagitis ( odds ratio=7.84, 47.16, 95% confidence interval as 2.04?30.20, 11.58?192.11, P<0.05). (4) Follow-up. All 130 patients were followed up for 17(range, 12?60)month after surgery. The BMI, percentage of total weight loss, diabetes remission rate, fasting blood glucose and glycosylated hemoglobin of the 130 patients at postoperative 12 month were (25±4)kg/m 2, 31%±8%, 84.6%(22/26), (5.6±1.2)mmol/L and 5.9%±1.3%. Conclusions:The sleeve gastrectomy and its plus procedures increase the risk of postoperative reflux esophagitis. Preoperative reflux diagnostic questionnaire scoring>0 and the occurrence of postoperative heartburn and acid regurgitation are independent risk factors of postoperative reflux esophagitis. Dietary adjustment and proton pump inhibitor therapy can alleviate symptoms of reflux esophagitis, but cannot cure reflux esophagitis.

Objective:To compare the 1-year effects of Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy with Roux-en-Y duodenal bypass (SG+RYDJB) on weight loss, remission of diabetes, and postoperative complications in patients with obesity and type 2 diabetes.Methods:A single-center retrospective cohort study was conducted at the First Affiliated Hospital of Nanjing Medical University from January 2020 to December 2020. Sixty-four patients with type 2 diabetes and body mass index (BMI) of 27.5-40.0 kg/m 2 were included in this study and divided into the RYGB group ( n=34) and the SG+RYDJB group ( n=30). In both procedures, the biliopancreatic branch was measured 100 cm distal to the Treitz ligament, and the food branch was measured 100 cm distal to the gastric or duodenojejunal anastomosis. Patients were followed up by telephone or WeChat, a free messaging and calling app at 1, 3, 6, and 12 months postoperatively to determine their weight loss and remission of diabetes. The primary outcomes were the weight loss and reduction in blood glucose concentrations at 1 year after surgery and postoperative complications. Other postoperative changes, including body weight, BMI, percentage of total weight loss (%TWL), percentage of excess weight loss (%EWL), glycated hemoglobin A1c (HbA1c), and fasting blood glucose at 1 year after surgery were also assessed. Results:There were no significant differences in baseline data between the two groups (all P>0.05). No conversion to open surgery or death occurred in either group. Operation time was longer in the SG+RYDJB than the RYGB group (137.8±22.1 minutes vs. 80.0±24.9 minutes, t=9.779, P<0.001) and the incidence of perioperative complications was higher in the SG+RYDJB than the RYGB group (20% [6/30] vs. 2.9% [1/34], χ 2=4.761, P=0.029). However, the postoperative hospital stay was similar between the two groups [3.0 (3.0, 4.3) days vs. 3.0 (4.0, 6.0) days, U=641.500, P=0.071]. Perioperative complications comprised small gastric pouch anastomotic leakage in one patient in the RYGB group and leakage (three patients) and bleeding (two patients with gastrointestinal bleeding and one with trocar site bleeding) in the SG+RYDJB group. Long-term complications were as follows. The incidence of anemia was significantly higher in the RYGB than the SG+RYDJB group (26.5% [9/34] vs. 3.3% [1/30], χ 2=6.472, P=0.011). However, there were no significant differences in incidences of postoperative reflux, dumping syndrome, alopecia, diarrhea, constipation or foul-smelling flatus between the two groups (all P>0.05). Compared with 1 year before surgery, the body weights and fasting plasma glucose concentrations of patients in the SG+RYDJB and RYGB group (72.4±10.6 kg vs. 98.5±14.2 kg, respectively; 68.2±10.0 kg vs. 91.9±14.8 kg, respectively), BMI (25.2±2.9 kg/m 2 vs. 34.3±4.2 kg/m 2, respectively; 24.3±2.4 kg/m 2 vs. 32.7±3.7 kg/m 2, respectively) (5.5±1.6 vs. 10.6±3.3, respectively; 5.8±2.1 vs. 9.0±3.4, respectively); HbA1c (5.7±0.8 vs. 9.7±1.2, respectively; 9.1±1.9 vs. 5.9±0.9, respectively) were significantly lower at 1 year after surgery (all P<0.05). However, the % TWL (26.5%±6.0% vs. 25.6%±4.4%, t=0.663, P=0.510) and % EWL (109.1%±38.2% vs. 109.4%±40.3%, t=-0.026, P=0.026), rate of complete remission of diabetes at 1 year (80.0% [24/30] vs. 82.4% [28/34], χ 2=0.058, P=0.810] did not differ significantly between the two groups (all P>0.05). Conclusions:Although SG+RYDJB surgery compared with RYGB is more difficult to perform, it can achieve similar weight loss and remission of diabetes and is associated with a lower incidence of anemia because of the preservation of the pylorus.

Objective:To compare the 1-year effects of Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy with Roux-en-Y duodenal bypass (SG+RYDJB) on weight loss, remission of diabetes, and postoperative complications in patients with obesity and type 2 diabetes.Methods:A single-center retrospective cohort study was conducted at the First Affiliated Hospital of Nanjing Medical University from January 2020 to December 2020. Sixty-four patients with type 2 diabetes and body mass index (BMI) of 27.5-40.0 kg/m 2 were included in this study and divided into the RYGB group ( n=34) and the SG+RYDJB group ( n=30). In both procedures, the biliopancreatic branch was measured 100 cm distal to the Treitz ligament, and the food branch was measured 100 cm distal to the gastric or duodenojejunal anastomosis. Patients were followed up by telephone or WeChat, a free messaging and calling app at 1, 3, 6, and 12 months postoperatively to determine their weight loss and remission of diabetes. The primary outcomes were the weight loss and reduction in blood glucose concentrations at 1 year after surgery and postoperative complications. Other postoperative changes, including body weight, BMI, percentage of total weight loss (%TWL), percentage of excess weight loss (%EWL), glycated hemoglobin A1c (HbA1c), and fasting blood glucose at 1 year after surgery were also assessed. Results:There were no significant differences in baseline data between the two groups (all P>0.05). No conversion to open surgery or death occurred in either group. Operation time was longer in the SG+RYDJB than the RYGB group (137.8±22.1 minutes vs. 80.0±24.9 minutes, t=9.779, P<0.001) and the incidence of perioperative complications was higher in the SG+RYDJB than the RYGB group (20% [6/30] vs. 2.9% [1/34], χ 2=4.761, P=0.029). However, the postoperative hospital stay was similar between the two groups [3.0 (3.0, 4.3) days vs. 3.0 (4.0, 6.0) days, U=641.500, P=0.071]. Perioperative complications comprised small gastric pouch anastomotic leakage in one patient in the RYGB group and leakage (three patients) and bleeding (two patients with gastrointestinal bleeding and one with trocar site bleeding) in the SG+RYDJB group. Long-term complications were as follows. The incidence of anemia was significantly higher in the RYGB than the SG+RYDJB group (26.5% [9/34] vs. 3.3% [1/30], χ 2=6.472, P=0.011). However, there were no significant differences in incidences of postoperative reflux, dumping syndrome, alopecia, diarrhea, constipation or foul-smelling flatus between the two groups (all P>0.05). Compared with 1 year before surgery, the body weights and fasting plasma glucose concentrations of patients in the SG+RYDJB and RYGB group (72.4±10.6 kg vs. 98.5±14.2 kg, respectively; 68.2±10.0 kg vs. 91.9±14.8 kg, respectively), BMI (25.2±2.9 kg/m 2 vs. 34.3±4.2 kg/m 2, respectively; 24.3±2.4 kg/m 2 vs. 32.7±3.7 kg/m 2, respectively) (5.5±1.6 vs. 10.6±3.3, respectively; 5.8±2.1 vs. 9.0±3.4, respectively); HbA1c (5.7±0.8 vs. 9.7±1.2, respectively; 9.1±1.9 vs. 5.9±0.9, respectively) were significantly lower at 1 year after surgery (all P<0.05). However, the % TWL (26.5%±6.0% vs. 25.6%±4.4%, t=0.663, P=0.510) and % EWL (109.1%±38.2% vs. 109.4%±40.3%, t=-0.026, P=0.026), rate of complete remission of diabetes at 1 year (80.0% [24/30] vs. 82.4% [28/34], χ 2=0.058, P=0.810] did not differ significantly between the two groups (all P>0.05). Conclusions:Although SG+RYDJB surgery compared with RYGB is more difficult to perform, it can achieve similar weight loss and remission of diabetes and is associated with a lower incidence of anemia because of the preservation of the pylorus.

The COVID-19 pandemic caused by the novel SARS-CoV-2 virus has caused havoc across the entire world. Even though several COVID-19 vaccines are currently in distribution worldwide, with others in the pipeline, treatment modalities lag behind. Accordingly, researchers have been working hard to understand the nature of the virus, its mutant strains, and the pathogenesis of the disease in order to uncover possible drug targets and effective therapeutic agents. As the research continues, we now know the genome structure, epidemiological and clinical features, and pathogenic mechanism of SARS-CoV-2. Here, we summarized the potential therapeutic targets involved in the life cycle of the virus. On the basis of these targets, small-molecule prophylactic and therapeutic agents have been or are being developed for prevention and treatment of SARS-CoV-2 infection.

Objective:To investigate the bleeding characteristic and influencing factors after bariatric surgery.Methods:The retrospective case-control study was conducted. The clinical data of 3 371 patients with obesity who underwent bariatric surgery in the First Affiliated Hospital of Nanjing Medical University from May 2010 to August 2021 were collected. There were 903 males and 2 468 females, aged 31(16?65)years. Observation indicators: (1) occurrence, diagnosis and treatment of bleeding after bariatric surgery; (2) analysis of influencing factors for bleeding after bariatric surgery. (3) Follow-up. Follow-up was conducted through outpatient examinations, telephone interview or WeChat to detect total weight loss rate, resolution of hypertension and remission of type 2 diabetes of the patients with bleeding after bariatric surgery. The follow-up was up to August 2021. Measurement data with normal distribution were represented as Mean± SD. Measurement data with skewed distribution were represented as M(range). Count data were represented as absolute numbers or percentages, and comparison between groups was analyzed by the chi-square test. Ordinal data were analzyed by the non-parametric rank sum test. Univariate analysis was conducted using the corresponding statistical methods based on data type. The binary Logistic regression was used for multivariate analysis. Results:(1) Occurrence, diagnosis and treatment of bleeding after bariatric surgery. There were 27 of 3 371 patients diagnosed with postoperative bleeding, including 13 males and 14 females. There were 18 cases of abdominal bleeding and 9 cases of gastrointestinal bleeding. Among the 27 patients with postoperative bleeding, 8 cases were diagnosed with bleeding on the day after operation, 13 cases were diagnosed on the first day after operation, 4 casess were diagnosed on the second day, and 2 cases were diagnosed on the third day or later. Among the 27 patients with postoperative bleeding, 24 cases had tachycardia as the main clinical manifestation, 11 patients had abnormal abdominal drainage with the drainage volume as 300(range, 100?600)mL, 6 cases had hematocheziain with the volume as 500(range, 120?1 000)mL, 5 cases were manifested as hypotension, 3 cases had hematemesis with the volume as 300(range, 50?800)mL, 2 cases had a significant decrease in hemoglobin on the first day after operation. One patient may have multiple clinical manifestations. Among the 27 patients with postoperative bleeding, 6 cases with abdominal bleeding received emergency laparotomy due to continuous increase of abdominal drainage or hemorrhagic shock, of which one patient died of heart failure after emergency reoperation. The time between primary and secondary operation was 13.5(range, 2.0?45.0)hours, and the volume of blood accumulation was 1 000(range, 600?7 000)mL. The bleeding sites were identified in 5 patients during reoperation, including 2 cases of staple line bleeding after sleeve gastrectomy, 1 case of lesser sac bleeding after Roux-en-Y gastric bypass, 1 case of short gastric vessel bleeding and 1 case of trocar site bleeding. One patient had no obvious active bleeding during reoperation. The remaining 12 cases of abdominal bleeding and 9 cases of gastrointestinal bleeding were treated by conservative therapy. The duration of bleeding lasted for (2.1±0.7)days. (2) Analysis of influencing factors for bleeding after bariatric surgery. Results of univariate analysis showed that gender, hypertension, type 2 diabetes, surgical type were the related factors that affected the bleeding after bariatric surgery ( χ2=6.33, 42.16, 4.49, 14.09, P<0.05). Results of multivariate analysis indicated that surgical type was a independent factor affecting postoperative bleeding in patients undergoing bariatric surgery ( odds ratio=1.69, 95% confidence interval as 1.18?2.41, P<0.05). (3) Follow-up. All the 27 patients were followed up for 16(1?62)months. Eighteen patients reached or exceeded the 12 months follow-up time point. The 1-year total weight loss rate was 36%±12%, the resolution proportion of hypertension was 8/11, and the complete remission proportion of type 2 diabetes was 6/7. Six patients reached or exceeded the 36 months follow-up time point. The 3-year total weight loss rate was 35%±12%, the resolution proportion of hypertension was 4/5, and the complete remission proportion of type 2 diabetes was 1/1. Conclusions:The incidence of post-operative bleeding after bariatric surgery is low. Tachycardia, abnormal abdominal drainage and hypotension have sentinel functions. Surgical type is a independent factor affecting bleeding after bariatric surgery.

Objective:To evaluate the improvement of papilledema and visual acuities in patients with idiopathic intracranial hypertension (IIH) after venous sinus stenting.Methods:The clinical data of 8 IIH patients who met the inclusion criteria underwent venous sinus stenting between January 2013 and December 2016 at Department of Neurosurgery, Tianjin Huanhu Hospital were analyzed retrospectively. There were 6 females and 3 males,aged (32.9±14.4)years (range:19 to 57 years).The thickness of the retinal nerve fiber layer (RNFL) was measured by optical coherence tomography. Fundus,visual acuity and visual field examination were performed before and after operation. If pressure gradient ≥10 mmHg(1 mmHg=0.133 kPa) across the venous stenosis was indicated by intraoperative pressure measurement,the patient would be treated with venous sinus stenting. Intracranial pressure was measured by lumbar puncture 3 to 7 days after operation. RNFL thickness and eye examination were detected 6 months after surgery. CT venogram was used to observe the sinus venous conditions. Paired t test was used to compare the data before and after surgery. Results:All the 8 patients underwent venous sinus stenting successfully. The mean pressure gradient across the venous stenosis was reduced from (24±9.2) mmHg to (2.6±2.0) mmHg ( t=8.02, P<0.01). Intracranial pressure decreased from preoperative (41.4±12.7) cmH 2O(1 cmH 2O=0.098 kPa) to postoperative (12.9±3.3) cmH 2O ( t=7.08, P<0.01). The RNFL thickness decreased from (275.3±68.3)μm to (131.4±31.8)μm( t=5.80, P<0.05) 6 months after surgery and the baseline visual acuity was improved from( M( Q R))0.24 (0.25) to 0.65 (0.23)( Z=-2.52, P<0.05).Papilledema was significantly improved in 6 patients,and no significant change in 2 patients. CT venogram indicated adjacent stent restenosis in 1 patient. Conclusion:Venous sinus stenting can effectively improve papilledema and visual acuity caused by IIH.

Objective:To evaluate the improvement of papilledema and visual acuities in patients with idiopathic intracranial hypertension (IIH) after venous sinus stenting.Methods:The clinical data of 8 IIH patients who met the inclusion criteria underwent venous sinus stenting between January 2013 and December 2016 at Department of Neurosurgery, Tianjin Huanhu Hospital were analyzed retrospectively. There were 6 females and 3 males,aged (32.9±14.4)years (range:19 to 57 years).The thickness of the retinal nerve fiber layer (RNFL) was measured by optical coherence tomography. Fundus,visual acuity and visual field examination were performed before and after operation. If pressure gradient ≥10 mmHg(1 mmHg=0.133 kPa) across the venous stenosis was indicated by intraoperative pressure measurement,the patient would be treated with venous sinus stenting. Intracranial pressure was measured by lumbar puncture 3 to 7 days after operation. RNFL thickness and eye examination were detected 6 months after surgery. CT venogram was used to observe the sinus venous conditions. Paired t test was used to compare the data before and after surgery. Results:All the 8 patients underwent venous sinus stenting successfully. The mean pressure gradient across the venous stenosis was reduced from (24±9.2) mmHg to (2.6±2.0) mmHg ( t=8.02, P<0.01). Intracranial pressure decreased from preoperative (41.4±12.7) cmH 2O(1 cmH 2O=0.098 kPa) to postoperative (12.9±3.3) cmH 2O ( t=7.08, P<0.01). The RNFL thickness decreased from (275.3±68.3)μm to (131.4±31.8)μm( t=5.80, P<0.05) 6 months after surgery and the baseline visual acuity was improved from( M( Q R))0.24 (0.25) to 0.65 (0.23)( Z=-2.52, P<0.05).Papilledema was significantly improved in 6 patients,and no significant change in 2 patients. CT venogram indicated adjacent stent restenosis in 1 patient. Conclusion:Venous sinus stenting can effectively improve papilledema and visual acuity caused by IIH.

Bariatric and metabolic surgery has become the clinical hot topic of the treatment of metabolic syndromes including obesity and diabetes mellitus, but how to choose the appropriate surgical procedure remains the difficult problem in clinical practice. Clinical guidelines of American Society for Metabolic and Bariatric Surgery(ASMBS)(version 2013) introduced the procedures of bariatric and metabolic surgery mainly including biliopancreatic diversion with duodenal switch(BPD-DS), laparoscopic adjustable gastric banding (LAGB), laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic sleeve gastrectomy(LSG). To choose the appropriate bariatric and metabolic procedure, the surgeons should firstly understand the indications and the contraindications of each procedure. Procedure choice should also consider personal condition (body mass index, comorbidities and severity of diabetes), family and socioeconomic status (postoperative follow-up attendance, understanding of potential surgical risk of gastrectomy and patient's will), family and disease history (patients with high risk of gastric cancer should avoid LRYGB; patients with gastroesophageal reflux disease should avoid LSG) and associated personal factors of surgeons. With the practice of bariatric and metabolic surgery, the defects, especially long-term complications, of different procedures were found. For example, LRYGB resulted in higher incidence of postoperative anemia and marginal ulcer, high risk of gastric cancer as well as the requirement of vitamin supplementation and regular follow-up. Though LSG has lower surgical risk, its efficacy of diabetes mellitus remission and long-term weight loss are inferior to the LRYGB. These results pose challenges to the surgeons to balance the benefits and risks of the bariatric procedures. A lot of factors can affect the choice of bariatric and metabolic procedure. Surgeons should choose the procedure according to patient's condition with the consideration of the choice of patients. The bariatric and metabolic surgery not only manages the diabetes mellitus and weight loss, but also results in the reconstruction of gastrointestinal tract and side effect. Postoperative surgical complications and nutritional deficiency should also be considered. Thereby, individualized bariatric procedure with the full consideration of each related factors is the ultimate objective of bariatric and metabolic surgery.
Anemia ; epidemiology ; Bariatric Surgery ; adverse effects ; methods ; statistics & numerical data ; Biliopancreatic Diversion ; adverse effects ; methods ; statistics & numerical data ; Body Mass Index ; Comorbidity ; Contraindications ; Diabetes Mellitus ; surgery ; Disease Management ; Gastrectomy ; adverse effects ; methods ; statistics & numerical data ; Gastric Bypass ; adverse effects ; methods ; statistics & numerical data ; Gastroesophageal Reflux ; Gastroplasty ; methods ; mortality ; statistics & numerical data ; Humans ; Informed Consent ; Laparoscopy ; adverse effects ; methods ; statistics & numerical data ; Long Term Adverse Effects ; epidemiology ; Malnutrition ; epidemiology ; Obesity ; surgery ; Patient Acuity ; Patient Care Planning ; Patient Compliance ; Postgastrectomy Syndromes ; epidemiology ; Postoperative Complications ; epidemiology ; Risk Assessment ; methods ; Risk Factors ; Stomach Neoplasms ; epidemiology ; Treatment Outcome ; Weight Loss