Objective To validate the efficacy of the prediction model for difficulty of peroral endoscopic myotomy (POEM) through an independent cohort. Methods A total of 617 patients with achalasia who underwent POEM at the Endoscopy Center of Zhongshan Hospital, Fudan University from January 2021 to December 2023 were included. The general data of patients were collected, and the predictive value of the prediction model for POEM difficulty in the validation cohort was estimated. The stratified analysis was undergone according to the difficulty risk scores. Results In 617 consecutive patients, technical difficulty was observed in 90 cases (14.6%). The predictive model demonstrated moderate discriminatory capacity with an area under the receiver operating characteristic curve (AUC) of 0.711 (95%CI 0.643-0.780). Patients were stratified into three risk categories according to the difficulty risk scores: low-risk (＜0.1), medium-risk (0.1-0.25), and high-risk (≥0.25). The corresponding technical difficulty rates were 7.3%, 16.9%, and 51.6%, respectively. Conclusion The prediction model for POEM difficulty built by our center shows good stability and discrimination, and has good clinical application value.

Objective To explore the feasibility, safety, and efficacy of transesophageal endoscopic surgery for mediastinal tumors. Methods A retrospective analysis was conducted on the clinical data of 17 patients who underwent transesophageal endoscopic resection for benign mediastinal tumors at the Endoscopy Center of Zhongshan Hospital, Fudan University, between January 1, 2016 and December 31, 2024. Epidemiological characteristics, surgical parameters, adverse events, and follow-up outcomes were analyzed. Results Among the 17 patients, there were 9 males and 8 females, with an average age of (42.4±14.5) years and an average tumor size of (2.6±1.6) cm. Pathological types included esophageal duplication cysts (6 cases, 35.3%), bronchogenic cysts (5 cases, 29.4%), gastroenteric cysts (3 cases, 17.6%), schwannomas (2 cases, 11.8%), and lymphangioma (1 case, 5.9%). Fourteen patients (82.4%) underwent submucosal tunneling endoscopic resection (STER), 3 patients (17.6%) underwent natural orifice transluminal endoscopic mediastinal surgery. All surgeries were successfully completed without conversion to open surgery. En bloc resection was achieved in 11 patients (64.7%), with an average operative time of (60.9±32.6) min. No intraoperative bleeding or mucosal injury occurred, and 4 patients (23.5%) experienced minor complications (pneumothorax, fever, recurrent laryngeal nerve injury), all of which resolved with conservative treatment. The average postoperative hospital stay was (3.2±1.5) days, and no recurrence was observed during the follow-up period. Conclusions Transesophageal endoscopic resection of benign mediastinal tumors is a safe, effective, and minimally invasive treatment method. Further validation of its efficacy and safety through large-scale prospective studies is warranted.

Objective To explore the short-term efficacy of endoscopic submucosal dissection (ESD) in the treatment of early carcinoma in the remnant stomach. Methods A retrospective study was conducted on 45 patients with early residual gastric cancer underwent ESD at the Endoscopy Center of Zhongshan Hospital, Fudan University from December 2014 to April 2024, with a total of 45 lesions. The patients were divided into an anastomotic group (n=15) and a non-anastomotic group (n=30) based on the location of tumor occurrence, and their clinical data, endoscopic diagnosis and treatment, and histopathological conditions were compared between the two groups. Results All 45 patients had lesions with redness and erosion. There were 9 cases of poor lifting of submucosal injection in the anastomotic group and 2 cases in the non-anastomotic group, respectively, and the difference was statistically significant (P<0.05). ESD surgery was performed on 13 lesions in the anastomotic group and 28 lesions in the non-anastomotic group, with surgery times of 80.00 (50.00, 100.00) min and 55.00 (43.75, 80.00) min, respectively. The difference in surgery time between the two groups was statistically significant (P=0.03). Among the 45 patients, ESD surgery achieved curative resection in 35 cases, including 11 cases in the anastomotic group and 24 cases in the non-anastomotic group, with no statistically significant difference. Conclusions Careful preoperative evaluation of early carcinoma in the remnant stomach is essential to prevent oversight. Lesions at anastomotic sites and suture lines present higher technical challenges for complete resection. ESD is safe and effective, with auxiliary traction technique available when necessary.

Objective To compare the efficacy and tolerability of the novel bowel-cleansing agent TCIC-001 and the traditional polyethylene glycol (PEG) regimen for bowel preparation prior to colonoscopy. Methods Prospective inclusion of 62 patients who were scheduled to undergo colonoscopy at Zhongshan Hospital, Fudan University from July 2021 to July 2022. They were randomly divided into TCIC-001 group (n=31) and PEG group (n=31) using a random number table method. The TCIC-001 group took TCIC-001 orally, drinking water in stages, with a total liquid intake of 1 500 mL; the PEG group took PEG orally, taking it in 4 doses, with a total liquid intake of 3 000 mL. The primary endpoint indicator is the quality of intestinal hygiene evaluated by the Boston Bowel Preparation Scale (BBPS), the secondary endpoint indicators were medication adherence, medication duration, frequency of bowel movements, duration of bowel movements, and incidence of adverse events between two groups. Results No significant differences were observed in sex, age, or defecation frequency between the two groups. For efficacy, both groups achieved equivalent bowel cleanliness, with a “good preparation” rate of 93.55% and comparable BBPS score of each intestinal segment and total scores. For tolerability, the TCIC-001 group had a shorter medication duration compared to the PEG group ([48.8±25.9] min vs [82.8±28.4] min, P<0.001), a longer defecation duration ([288.6±74.0] min vs [236.5±74.3] min, P<0.001), and a lower incidence of first defecation before medication completion (9.68% vs 41.94%, P=0.004). Regarding safety, no significant differences were observed between the TCIC-001 group and the PEG group in incidences of chloride disturbances (0% vs 9.68%) and calcium disturbances (3.23% vs 6.45%), and no other adverse events. Conclusions TCIC-001 demonstrated comparable bowel-cleansing efficacy to PEG while significantly improving tolerability (reduced medication time and lower risk of premature defecation) and maintaining favorable safety.

Objective To evaluate the efficacy and safety of a novel gastrointestinal mucosal elevation gel in vivo porcine model. Methods Eight healthy white pigs were selected, which were uesd to bump height evaluation (n=2) and safety evaluation (n=6). The sample (alimentary canal mucosa bump gel sample) and the control sample (disposable endoscopic submucosal filler of alimentary canal) were respectively injected into the submucosa of pig gastric antrum and gastric body. In the evaluation of elevation height, the morphology, persistence, and clinical safety of mucosal elevation were observed and recorded immediately and 30 minutes after injection. In safety evaluation, endoscopic mucosal resection was performed after injection, and the mucosal protrusion shape, product efficacy, and clinical safety were observed and recorded at immediate and 7-day time points. After observation, all animals were euthanized and tissue samples were collected and excised for histopathological evaluation. Results In elevation height evaluation, sample group showed a steep elevation immediately after surgery, exhibiting a more pronounced elevation morphology compared to control group (P=0.019). Only two (25%) sites of the elevation showed slight collapse in 30 minutes after surgery, and the durability notably increased compared to control group (8 all collapsed, P＜0.001). In safety evaluation, the average trauma area of sample group was 1.77 mm², which was significantly lower than control group (2.65 mm², P＜0.001). There was no statistical difference among average injection dose per unit area, surgical time per unit area, and en bloc resection rate. Sample group showed mild ulcers and only 1 (12.5%) site of mild bleeding at immediate time point after surgery. No bleeding, perforation, ulcer or edema was observed in sample group 7 days after surgery, and no statistical difference was identified compared to control group. Histopathological evaluation found that the gastric antrum and body tissues exhibited moderate injury and mild edema at immediate time point, accompanied by mild inflammatory cellular infiltration. At 7-day time point, gastric antrum tissues demonstrated moderate injury, mild edema and mild inflammatory cellular infiltration, with 1 (12.5%) site of tissues infected, while in gastric body tissues, no bleeding was observed, whereas moderate injury and mild edema were evident, accompanied by mild inflammatory cellular infiltration and 3 (37.5%) sites of tissues infected, all of which were not statistically different from control group. Conclusion The novel gastrointestinal mucosal elevation gel exhibited steep elevation morphology, long-lasting elevation height, and favorable efficacy and safety in preclinical animal trials, showing enormous clinical application potential.

Objective To explore the feasibility and safety of submucosal tunneling endoscopic resection(STER)for the treatment of giant(long diameter≥3.5 cm)symptomatic submucosal tumors(SMT)originating from the esophageal and cardiac muscularis propria layer.Methods A retrospective analysis was conducted on patients with giant symptomatic SMT of the esophagus and cardia treated with STER at the Endoscopy Center of Zhongshan Hospital,Fudan University from January 2017 to January 2020.Clinical characteristics and follow-up data of patients were collected.The efficacy of STER was evaluated by complete resection rate,recurrence rate,and residual rate.The safety of the procedure was assessed by the occurrence of procedure-related complications.Results A total of 111 patients with SMT were included,including 65 males and 46 females,with an average age of(43.2±11.6)years old.Among them,11 patients(9.9％)presented with typical symptoms.Leiomyomas accounted for 105 cases,gastrointestinal stromal tumors for 2 cases,and schwannoma for 4 cases.The median long diameter of the tumors was 5 cm,and the median short diameter was 3 cm.The median operation time was 70 minutes,and the median time of hospital stay was 3 days.The success rate of STER was 100％,with a complete resection rate of 73.9％.Intraoperative mucosal injury was observed in 18 cases(16.2％),postoperative complications occurred in 16 cases(14.4％),including severe pneumothorax/pleural effusion requiring drainage in 10 cases(9.0％),delayed bleeding in 1 case(0.9％),moderate or severe fever in 4 cases(3.6％),and infection in tunnel in 1 case(0.9％).Follow-up at 1-18 months showed no tumor residue,recurrence,esophageal stenosis,diverticula or other long-term complications.Conclusions STER is a safe and effective treatment for giant symptomatic SMT of the esophagus and cardia.

Objective:To investigate the safety and feasibility of endoscopic full-thickness resection (EFTR) in the treatment of near-clinical complete response (near-cCR) rectal cancer after neoadjuvant therapy.Methods:A 74-year-old female patient with cT3N0M0 stage rectal adenocarcinoma who refused radical surgery for rectal cancer underwent neoadjuvant chemoradiotherapy (5 cycles of CapeOx chemotherapy and concurrent radiotherapy for 25 sessions) after multidisciplinary team discussion. One month after completing neoadjuvant treatment, reassessment including digital rectal examination, colonoscopy, and pelvic enhanced magnetic resonance imaging suggested near-cCR. Despite this, the patient requested rectal-preserving therapy. Subsequently, EFTR was performed five weeks after completion of neoadjuvant treatment. Postoperatively, supportive care including fasting, antimicrobial therapy, and nutritional support was provided. The patient started a liquid diet on the 6th day postoperatively and was discharged on the 13th day.Results:Pathological analysis revealed tubular adenoma with low-grade epithelial dysplasia, with negative margins and negative involvement of the base. During one-year follow-up, there were no signs of local regrowth or distant metastasis, and satisfactory anal function was observed.Conclusion:EFTR is safe and feasible in patients with near-cCR rectal cancer after neoadjuvant therapy. This approach should be considered after thorough evaluation of the patient's condition.

Objective:To analyze the clinical features of gastritis cystica profunda (GCP) and investigate the risk factors associated with its coexistence with gastric cancer.Methods:Data of 149 patients with pathologically confirmed GCP at Zhongshan Hospital of Fudan University between January 2015 and March 2022 were retrospectively analyzed for basic information, clinical data, lesion manifestations and pathological results, of which 106 were pathologically confirmed GCP after endoscopic resection and 43 others were pathologically confirmed GCP after surgical procedures. Among 149 patients, 56 were in the simple GCP group, and 93 in the GCP combined with gastric cancer group.Results:In the simple GCP group of 56 patients, 62.5% (35/56) were male and the mean age was 58.8 years. The predominant site of involvement was in the upper gastric segment (cardia and fundus) (51.8%,29/56), with manifestations primarily of the polypoid bulge type (41.1%,23/56) and submucosal bulge type (35.7%,20/56). Clinical symptoms were mostly atypical. In the group where GCP was combined with gastric cancer (93 cases), males accounted for 90.3% (84/93), the median age was 66.9 years, the upper gastric segment was predominantly affected (75.3%, 70/93), with differentiated cancer being the most common histological type (91.4%, 85/93). For 76 cases of early gastric cancer combined with GCP, mucosal lesions were the main presentation (73.7%, 56/76) with atypical clinical symptoms. Furthermore, in 17 cases of progressive gastric cancer combined with GCP, the manifestations were mainly bulging ulcers (88.2%, 15/17), and most of them were referred to the doctor because of abdominal pain and black stools (100.0%, 17/17). Binary logistic regression analysis showed that being male ( P=0.004, OR=4.411, 95% CI: 1.621-12.002), age ( P=0.001, OR=1.085, 95% CI: 1.036-1.136) and endoscopic manifestations of mucosal lesions ( P<0.001, OR=5.080, 95% CI: 2.162-11.939) were risk factors for GCP combined with gastric cancer, but involvement of the upper gastric segment was not related to combination with gastric cancer ( P=0.430, OR=0.707, 95% CI: 0.299-1.672). Among 106 patients with endoscopic resection, 57 cases of early gastric cancer combined with GCP had a median lesion length of 2.50 cm; 49 cases of GCP alone had a median lesion length of 1.20 cm, with significant difference ( Z=-5.503, P<0.001). All upper gastric GCP combined with early gastric cancer in endoscopically treated patients were cancers of the cardia, most of which were superficial elevation with the concave type (0-Ⅱa+Ⅱc) (44.7%, 21/47). 75.4% (43/57) patients with gastric cancer combined with GCP were graded as curative resection (eCuraA) after endoscopic surgery , and none of those who had additional surgery after endoscopic surgery had lymph node metastasis. There were 8 cases with history of gastric surgery, 7 of esophageal cancer, and 10 of multiple neoplastic gastric lesions in the 149 patients with GCP. Conclusion:GCP often occurs in the upper gastric region and is not inherently associated with the presence of gastric cancer. However, when coexisting with gastric cancer, it tends to affect elderly men, present with mucosal lesions of a differentiated histological type, and may be accompanied by esophageal or other gastric cancers. Notably, GCP is frequently identified as para-cancerous lesion, and endoscopic treatment emerges as a safe and effective approach, characterized by a high rate of curative endoscopic resections and a low incidence of lymphatic metastases.

Gastrointestinal tumors are a serious and threatening public health concern.Endoscopic minimally invasive treatment is an im-portant way to achieve early diagnosis and treatment of gastrointestinal tumors.Here,we summarize the history and current status of en-doscopic minimally invasive resection of early-stage gastrointestinal tumors,and explain the application of the new ERBEC concepts of endo-scopic minimally invasive surgery for the treatment of gastrointestinal tumors,which include elements,reservation-resection,bilateral-bene-fit,expansion,and collaboration.We also discuss the future direction of endoscopic minimally invasive resection for gastrointestinal tumors.