Objective:To investigate the endoscopic and pathological characteristics of metachronous early gastric cancer (EGC) after endoscopic submucosal dissection (ESD) for EGC.Methods:Data of 451 consecutive EGC patients treated with ESD at the Department of Gastroenterology, Peking University Third Hospital between 1 January, 2005 and 31 December, 2022 were retrospectively collected, of which 252 patients who met the criteria and had endoscopic follow-up ≥ 1 year were enrolled in the retrospective dynamic cohort. Multivariate Cox regression analysis was used to identify independent risk factors for metachronous EGC after ESD. Pearson's contingency coefficient was applied to analyze endoscopic correlation between the index and metachronous lesions. T-test, χ2 test, and Fisher exact test were used to compare endoscopic pathological features between index and metachronous lesions, the proportion of lesions meeting absolute ESD indication and their maximum diameters between patients undergoing annual vs bi-annual follow-up. Kaplan-Meier analysis assessed the cumulative incidence of metachronous EGC. Results:During a median follow-up of 40 months, 26 patients [10.3% (26/252)] developed metachronous EGC, with a mean interval of 43.9 months. Multivariate Cox regression identified the independent risk factors of index lesions including location in the middle third of the stomach ( HR=3.783, 95% CI: 1.300-11.011, P=0.015), in the anterior wall ( HR=3.934, 95% CI: 1.113-13.904, P=0.033), and the maximum diameter <15 mm ( HR=3.034, 95% CI: 1.074-8.571, P=0.036). Pearson's contingency coefficient showed no significant concordance between index and metachronous lesions for vertical location (C=0.375, P=0.372), horizontal location (C=0.508, P=0.434), gross morphology (C=0.287, P=0.675), or ulcer presence (C=0.194, P=0.313). Compared to index lesions, metachronous lesions were more frequently located on the posterior wall (lesser curvature/greater curvature/anterior wall/posterior wall: 11/2/1/12 VS 96/49/46/61, P=0.031), more often differentiated (differentiated/undifferentiated: 26/0 VS 214/38, P=0.032), and smaller in maximum diameter (8.08±5.99 mm VS 13.95±10.26 mm, t=4.383, P<0.001). No significant differences were observed between patients undergoing annual vs bi-annual follow-up in the proportion of metachronous lesions meeting absolute ESD indication (14/16 VS 9/9, P=0.520) or in maximum diameter (8.11±6.94 mm VS 6.67±4.35 mm, t=-0.275, P=0.535). The cumulative incidence curve of metachronous EGC plateaued after 10 years. Conclusion:Patients with EGC located in the middle third of the stomach, in the anterior wall, or of smaller diameter need intensive endoscopic surveillance after ESD. Posterior wall deserves particular attention during follow-up, with annual endoscopy recommended for at least 10 years post-ESD.

Objective:To explore and evaluate the optimization and application of case-based learning (CBL) in the reform practice for integrated curriculum of the digestive system.Methods:The 174 undergraduate students majoring in eight-year clinical medicine enrolled in 2019 at the Peking University Health Science Center were selected as research objects. CBL was used in the integration and optimization of the digestive system curriculum. These included increasing class hours, selecting disease modules, lesson preparation involving multi-disciplinary teachers, and joint teaching. Upon completion of teaching, a comprehensive evaluation of teaching effectiveness was conducted through questionnaires administrated to teachers and students, feedback from supervision experts, and scores of students. SPSS 21.0 was used for the t-test and a reliability analysis was conducted on the questionnaire results. Results:Teachers, students, and supervision experts were highly satisfied with CBL. More than 95% of teachers believed that joint teaching facilitated the sharing of diverse professional knowledge among teachers, enhanced the in-depth instruction of imaging knowledge, promoted the transformation of teaching ideas, and improved teaching ability. More than 70% of students agreed that joint teaching deepened their understanding of diseases, stimulated learning interest, and established a theoretical foundation for clinical practice. The average score of class performance was (47.60±2.41) points (a total score of 50 points). The answers of students to case-based questions in final exams were satisfactory. The average score of final evaluation was (82.24±8.82) points.Conclusions:The optimization and application of CBL in the integrated curriculum of the digestive system is highly accepted by teachers and students. This method improves the interest of learning and facilitates the establishment of overall medical thinking and clinical thinking in students.

Objective:To explore and evaluate the optimization and application of case-based learning (CBL) in the reform practice for integrated curriculum of the digestive system.Methods:The 174 undergraduate students majoring in eight-year clinical medicine enrolled in 2019 at the Peking University Health Science Center were selected as research objects. CBL was used in the integration and optimization of the digestive system curriculum. These included increasing class hours, selecting disease modules, lesson preparation involving multi-disciplinary teachers, and joint teaching. Upon completion of teaching, a comprehensive evaluation of teaching effectiveness was conducted through questionnaires administrated to teachers and students, feedback from supervision experts, and scores of students. SPSS 21.0 was used for the t-test and a reliability analysis was conducted on the questionnaire results. Results:Teachers, students, and supervision experts were highly satisfied with CBL. More than 95% of teachers believed that joint teaching facilitated the sharing of diverse professional knowledge among teachers, enhanced the in-depth instruction of imaging knowledge, promoted the transformation of teaching ideas, and improved teaching ability. More than 70% of students agreed that joint teaching deepened their understanding of diseases, stimulated learning interest, and established a theoretical foundation for clinical practice. The average score of class performance was (47.60±2.41) points (a total score of 50 points). The answers of students to case-based questions in final exams were satisfactory. The average score of final evaluation was (82.24±8.82) points.Conclusions:The optimization and application of CBL in the integrated curriculum of the digestive system is highly accepted by teachers and students. This method improves the interest of learning and facilitates the establishment of overall medical thinking and clinical thinking in students.

Objective:To investigate the endoscopic and pathological characteristics of metachronous early gastric cancer (EGC) after endoscopic submucosal dissection (ESD) for EGC.Methods:Data of 451 consecutive EGC patients treated with ESD at the Department of Gastroenterology, Peking University Third Hospital between 1 January, 2005 and 31 December, 2022 were retrospectively collected, of which 252 patients who met the criteria and had endoscopic follow-up ≥ 1 year were enrolled in the retrospective dynamic cohort. Multivariate Cox regression analysis was used to identify independent risk factors for metachronous EGC after ESD. Pearson's contingency coefficient was applied to analyze endoscopic correlation between the index and metachronous lesions. T-test, χ2 test, and Fisher exact test were used to compare endoscopic pathological features between index and metachronous lesions, the proportion of lesions meeting absolute ESD indication and their maximum diameters between patients undergoing annual vs bi-annual follow-up. Kaplan-Meier analysis assessed the cumulative incidence of metachronous EGC. Results:During a median follow-up of 40 months, 26 patients [10.3% (26/252)] developed metachronous EGC, with a mean interval of 43.9 months. Multivariate Cox regression identified the independent risk factors of index lesions including location in the middle third of the stomach ( HR=3.783, 95% CI: 1.300-11.011, P=0.015), in the anterior wall ( HR=3.934, 95% CI: 1.113-13.904, P=0.033), and the maximum diameter <15 mm ( HR=3.034, 95% CI: 1.074-8.571, P=0.036). Pearson's contingency coefficient showed no significant concordance between index and metachronous lesions for vertical location (C=0.375, P=0.372), horizontal location (C=0.508, P=0.434), gross morphology (C=0.287, P=0.675), or ulcer presence (C=0.194, P=0.313). Compared to index lesions, metachronous lesions were more frequently located on the posterior wall (lesser curvature/greater curvature/anterior wall/posterior wall: 11/2/1/12 VS 96/49/46/61, P=0.031), more often differentiated (differentiated/undifferentiated: 26/0 VS 214/38, P=0.032), and smaller in maximum diameter (8.08±5.99 mm VS 13.95±10.26 mm, t=4.383, P<0.001). No significant differences were observed between patients undergoing annual vs bi-annual follow-up in the proportion of metachronous lesions meeting absolute ESD indication (14/16 VS 9/9, P=0.520) or in maximum diameter (8.11±6.94 mm VS 6.67±4.35 mm, t=-0.275, P=0.535). The cumulative incidence curve of metachronous EGC plateaued after 10 years. Conclusion:Patients with EGC located in the middle third of the stomach, in the anterior wall, or of smaller diameter need intensive endoscopic surveillance after ESD. Posterior wall deserves particular attention during follow-up, with annual endoscopy recommended for at least 10 years post-ESD.

Objective:To analyze the effects of the primary location of colorectal cancer on the surgical outcome of liver metastases.Methods:A cross-sectional study was conducted on 178 patients with liver metastases from colorectal cancer admitted to Binzhou Central Hospital from January 2012 to January 2022. According to whether the patients had recurrence after surgery, they were divided into a recurrence group ( n = 88) and a control group ( n = 90). The general and clinical data were compared between the two groups. Logistic multivariate analysis of the factors with statistical significance was further performed to identify the risk factors of postoperative recurrence of liver metastases from colorectal cancer after surgery. The correlation between the primary location of colorectal cancer and each risk factor was analyzed. The recurrence of colorectal cancer was compared anong patients with different primary locations of colorectal cancer at 12 months after surgery. Results:Primary location at the right colon [55.68% (49/88), lymph node metastasis [92.05% (81/88)], D-dimer ≥ 180 μ g/L, albumin < 29 g/L, ineffective/no neoadjuvant chemotherapy [43.18% (33/38)], and high-risk clinical risk score [53.41% (47/88)] were risk factors for postoperative recurrence of liver metastases from colorectal cancer after surgery ( P = 0.024, 0.019, 0.001, 0.028, < 0.001, 0.001). The primary location of colorectal cancer was positively correlated with lymph node metastasis, D-dimer, and clinical risk score ( P = 0.043, 0.046, 0.030), and negatively correlated with albumin and the efficacy of neoadjuvant chemotherapy ( P = 0.004, 0.033). In 178 patients, the recurrence rate of liver metastases from colorectal cancer at 3 months [53.57% (15/70)], 6 months [55.17% (32/70)], and 12 months [55.68% (49/70)] was significantly higher in the right colon compared with the left colon [32.14% (9/40), 24.14% (14/40), 26.14% (23/40) and the rectum [14.29% (4/68), 20.69% (12/68), 18.18% (16/68)] ( χ2= 4.73, 7.85, 6.27, all P < 0.05). Conclusion:Right colon, lymph node metastasis, D-dimer, albumin, neoadjuvant chemotherapy efficacy, and clinical risk score are the risk factors for postoperative recurrence of liver metastases from colorectal cancer. Patients with the primary location at the right colon have a higher postoperative recurrence rate.

Objective:To investigate the classification of main pancreatic duct and treatment strategy after linear stapler closure of pancreatic neck in laparoscopic pancreaticoduodenectomy (LPD).Methods:The records of 51 consecutive patients with LPD who were treated by linear staple closure technique of pancreatic neck from February to December 2022 from Binzhou Second People′s Hospital, Shijingshan Campus, Beijing Chaoyang Hospital, Capital Medical University, Rizhao Hepatobiliary-Pancreatic-Splenic Surgery Research Institute, Chaoyang Central Hospital, Shandong Juxian People′s Hospital, Weihai Municipal Hospital, Binzhou Central Hospital, and Affiliated Hospital of Chifeng University were retrospectively reviewed. According to the visibility, position and diameter of the main pancreatic duct at the stump of the pancreas, the type of main pancreatic duct was divided into type I, type Ⅱ, type Ⅲa and type Ⅲb. The number of cases in each main pancreatic duct classification and the corresponding treatment strategies were examined.Results:A total of 51 cases of LPD were successfully completed. Of these patients, the males comprised 56.9%(29/51), and females comprised 43.1%(22/51), with age ranging from 31 to 88 years old. The type of the main pancreatic duct at the stump of the pancreas included 7 cases (13.7%) of type Ⅰ, 39 cases (76.5%) of type Ⅱ, 2 cases (3.9%) of type Ⅲa, and 3 cases (5.9%) of type Ⅲb. Corresponding treatment strategies were adopted according to different main pancreatic duct types, the main pancreatic duct was successfully found, and a support drainage tube was inserted.Conclusion:After linear stapler closure of pancreatic neck, corresponding treatment strategies should be adopted according to the classification of the main pancreatic duct, which would help to improve the success rate of finding the main pancreatic duct and placing a support drainage tube.

Objective:To study the use of primary continuous single-layer pancreaticojejunostomy after linear stapler closure of pancreatic neck in pancreaticoduodenectomy (PD).Methods:The clinical data of 21 patients who were treated with primary continuous single-layer pancreaticojejunostomy after linear stapler closure of pancreatic neck in PD at Beijing Chaoyang Hospital Affiliated, West Campus, Capital Medical University, Rizhao Hepatobiliary-pancreatic-splenic Surgery Research Institute, Binzhou Second People’s Hospital, Chaoyang Central Hospital from February 2022 to May 2022 were retrospectively analyzed. There were 12 males and 9 females, with ages ranging from 31.0 to 82.0 years (median age 63.0 years). The success rates of linear stapling at pancreatic neck, time of pancreaticojejunostomy, postoperative complications, pancreatic fistula risk score, and length of hospital stay were studied.Results:Among the 21 patients, there were 3 patients who underwent open PD and 18 patients who underwent laparoscopic PD. Primary continuous single-layer pancreaticojejunostomy after linear stapler closure of pancreatic neck was successfully carried out in all these patients. The success rate was 100.0%. The success rate of finding pancreatic ducts at the pancreatic stumps and inserting an drainage tube was 100.0%(21/21). In the 3 patients who underwent open PD, the operation time were 230.0, 245.0 and 250.0 minutes respectively. The time for completing pancreaticojejunostomy were 12.0, 13.0 and 12.0 minutes respectively. The estimated blood loss were 300.0, 450.0 and 600.0 ml respectively. The length of hospital stay were 14.0, 15.0 and 21.0 days. In the 18 patients who underwent laparoscopic PD, the operation time was (295.9±14.5) min, the time for constructing pancreaticojejunostomy was (22.3±1.5) min, the blood loss was (180.0±40.0) ml, the length of hospital stay ranging from 8.0 to 16.0 days (median 10.5 days). Among all the 21 patients, the pancreatic fistula risk score was (4.7±1.5). Postoperative acute pancreatitis occurred in 3 patients (14.3%), delayed gastric emptying occurred in 4 patients (19.0%), and all of them recovered after conservative treatment. There was no postoperative bleeding, nosocomial infection, grade B and C postoperative pancreatic fistula or perioperative death.Conclusion:The continuous single-layer pancreaticojejunostomy after linear stapler closure of the pancreatic neck was safe, reliable, simple and technically easy. It has the potential to prevent clinical postoperative pancreatic fistula and pancreaticojejunostomy bleeding. It is worth to popularize this surgical procedure.

Objective:To investigate the significance of MLH1 protein expression and MLH1 gene methylation rate between metastatic solid pseudopapillary tumor of pancreas (SPT) and non-metastatic SPT, and to explore the correlation between MLH1 gene methylation and SPT metastasis.Methods:Twelve metastatic SPT patients admitted to Peking University People's Hospital, Rizhao Central Hospital and Chaoyang Central Hospital of Liaoning Province from January 2009 to May 2022 were studied retrospectively, including 3 males and 9 females, with a median age of 47 years old, ranging from 21 to 73 years old. Thirty non-metastatic SPT patients with clear diagnosis, clear medical history and complete follow-up data from pathological database of Peking University People's Hospital from January 2009 to May 2017 were selected as the control group, including 12 males and 18 females, with a median age of 42 years old, ranging from 34 to 69 years old. Clinical data such as gender, age and pathological data were collected. Immunohistochemical expression of MLH1 protein and methylation of MLH1 gene were detected by pathological paraffins.Results:There was no significant difference in general data between the two groups (all P>0.05). Among the 12 metastatic SPT patients, 4 cases metastasized to liver, 2 to spleen, 2 to lung, 2 to lymph nodes, 1 to mediastinum, and 1 to sacrum. Compared with the non-metastatic tissue, the MLH1 protein deletion in metastatic pancreatic lesions (metastatic SPT-P) and metastatic lesions (metastatic SPT-M) were increased [both 33.3%(4/12)], and the difference was statistically significant (both Chi square=5.00, both P=0.041). Compared with 0 (0/30) MLH1 gene methylation rate in non-metastatic SPT tissues, the methylation rate of MLH1 gene in metastatic SPT-M and metastatic SPT-P tissues [both 30% (3/10)] were higher, with statistical significance (both Chi square=0.96, both P=0.032). Conclusion:Compared with non-metastatic SPT, the loss rate of MLH1 protein expression and MLH1 gene methylation are increased in metastatic SPT. MLH1 methylation may occur before metastasis, which can be used as a predictor of SPT metastasis.

Objective:To explore the perivenous blocking management strategy for portal vein-superior mesenteric vein (PSMV) resection and reconstruction and its effect on postoperative complications in patients undergoing pancreaticoduodenectomy (PD).Methods:The data of 137 patients with pancreatic cancer treated with PD in Beijing Chaoyang Hospital Affiliated to Capital Medical University, Chaoyang Central Hospital, the Second Hospital of Chaoyang, Rizhao Central Hospital, the Second People's Hospital of Binzhou from January 2010 to December 2020 were collected. There were 83 males and 54 females with an average age of 61.8 years. There were 42 patients in the reconstruction group and 95 patients in the control group. The main intraoperative indexes and postoperative complications were compared between the two groups with the aim to review our experience in PSMV resection and reconstruction by using the perivenous blocking management strategy.Results:PD was successfully completed in 137 patients in the reconstruction group, the PSMV blocking time was 15-120 min, with a median of 30 min. The operation time 380 (330, 465) min, intraoperative blood loss 725 (500, 1000) ml, and postoperative hospital stay 21.0 (16.0, 28.0) d in the reconstruction group were significantly higher than those of control group [305 (280, 340) min, 400 (300, 500) ml and 18.0 (14.0, 24.5) d] (all P<0.05). The reoperation rate and perioperative mortality were 4.8% (2/42) and 2.4% (1/42) in the reconstruction group, while 2.1% (2/95) and 1.0% (1/95) in the control group, respectively. There was no significant difference between the two groups (both P>0.05). The incidence of pancreatic fistula, peritoneal effusion and infection, pulmonary infection of the reconstruction group was significantly higher than those of the control group ( P<0.05). There was no significant difference in the incidence of postoperative bleeding, delayed gastric emptying, biliary fistula, incision infection, reoperation between the two groups ( P>0.05). Conclusions:PSMV resection and reconstruction significantly increased the incidences of complication after PD, including pancreatic fistula, peritoneal effusion/infection and pulmonary infection. The perivenous blocking management strategy significantly promoted smooth postoperative recovery and effectively reduced morbidity rates of postoperative bleeding and mortality after PSMV resection and reconstruction in PD.

Objective:To study the impact of Roux-en-Y reconstruction with isolated pancreatic drainage (RYR) on delayed gastric emptying (DGE) after pancreaticoduodenectomy (PD).Methods:The data of 203 patients who underwent PD at 5 clinical centers from January 2014 to June 2020 were collected. According to the method of reconstruction of the digestive tract, the patients were divided into the RYR group ( n=88) and the conventional loop reconstruction (CLR) group ( n=115). The incidence and severity of DGE were compared between groups. The risk factors of clinically relevant DGE (CR-DGE) after PD were analysed by univariate and multivariate analyses. Results:Of 203 patients, there were 124 males and 79 females, aged (61.6±10.2) years. The overall incidence of DEG was 27.6% (56/203). The incidence of CR-DGE in the RYR group was significantly lower than that in the CLR group [13.6%(12/88) vs 26.1%(30/115), P=0.030]. Patient age of more than 65 years ( OR=2.966, 95% CI: 1.162-8.842, P=0.024), clinically relevant pancreatic fistula ( OR=3.041, 95% CI: 1.122-8.238, P=0.029), ascites and abdominal infection ( OR=10.000, 95% CI: 2.552-39.184, P=0.001), and CLR ( OR=3.206, 95% CI: 1.162-8.842, P=0.024) were identified as independent risk factors for CR-DGE. The duration of hospitalization and hospital expenditure of patients were significantly increased in the CR-DGE group ( P<0.05). Conclusions:Patients over 65 years with clinically relevant pancreatic fistula, with ascites or abdominal infection after operation, had a higher evidence of CR-DGE. Roux-en-Y reconstruction with isolated pancreatic could helped to decrease the incidence of CR-DGE after PD.