[Endoscopic full-thickness resection in near clinical complete response rectal cancer after neoadjuvant therapy]

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.

Biomechanical Evaluation of 2 Endoscopic Spine Surgery Methods for Treating Lumbar Disc Herniation: A Finite Element Study

OBJECTIVE

This study aimed to evaluate the effects of 2 endoscopic spine surgeries on the biomechanical properties of normal and osteoporotic spines.

METHODS

Based on computed tomography images of a healthy adult volunteer, 6 finite element models were created. After validating the normal intact model, a concentrated force of 400 N and a moment of 7.5 Nm were exerted on the upper surface of L3 to simulate 6 physiological activities of the spine. Five types of indices were used to assess the biomechanical properties of the 6 models, range of motion (ROM), maximum displacement value, intervertebral disc stress, maximum stress value, and articular protrusion stress, and by combining them with finite element stress cloud.

RESULTS

In normal and osteoporotic spines, there was no meaningful change in ROM or disc stress in the 2 surgical models for the 6 motion states. Model N1 (osteoporotic percutaneous transforaminal endoscopic discectomy model) showed a decrease in maximum displacement value of 20.28% in right lateral bending. Model M2 (unilateral biportal endoscopic model) increased maximum displacement values of 16.88% and 17.82% during left and right lateral bending, respectively. The maximum stress value of L4-5 increased by 11.72% for model M2 during left rotation. In addition, using the same surgical approach, ROM, maximum displacement values, disc stress, and maximum stress values were more significant in the osteoporotic model than in the normal model.

CONCLUSION

In both normal and osteoporotic spines, both surgical approaches were less disruptive to the physiologic structure of the spine. Furthermore, using the same endoscopic spine surgery, normal spine biomechanical properties are superior to osteoporotic spines.

Unintrusive multi-cancer detection by circulating cell-free DNA methylation sequencing (THUNDER): development and independent validation studies

BACKGROUND

Early detection of cancer offers the opportunity to identify candidates when curative treatments are achievable. The THUNDER study (THe UNintrusive Detection of EaRly-stage cancers, NCT04820868) aimed to evaluate the performance of ELSA-seq, a previously described cfDNA methylation-based technology, in the early detection and localization of six types of cancers in the colorectum, esophagus, liver, lung, ovary and pancreas.

PATIENTS AND METHODS

A customized panel of 161,984 CpG sites was constructed and validated by public and in-house (cancer: n=249; non-cancer: n=288) methylome data, respectively. The cfDNA samples from 1,693 participants (cancer: n=735; non-cancer: n=958) were retrospectively collected to train and validate two multi-cancer detection blood test models (MCDBT-1/2) for different clinical scenarios. The models were validated on a prospective and independent cohort of age-matched 1,010 participants (cancer: n=505; non-cancer: n=505). Simulation using the cancer incidence in China was applied to infer stage-shift and survival benefits to demonstrate the potential utility of the models in the real world.

RESULTS

MCDBT-1 yielded a sensitivity of 69.1% (64.8%‒73.3%), a specificity of 98.9% (97.6%‒99.7%) and tissue origin accuracy of 83.2% (78.7%‒87.1%) in the independent validation set. For early stage (I‒III) patients, the sensitivity of MCDBT-1 was 59.8% (54.4%‒65.0%). In the real-world simulation, MCDBT-1 achieved the sensitivity of 70.6% in detecting the six cancers, thus decreasing late-stage incidence by 38.7%‒46.4%, and increasing 5-year survival rate by 33.1%‒40.4%, respectively. In parallel, MCDBT-2 was generated at a slightly low specificity of 95.1% (92.8%-96.9%) but a higher sensitivity of 75.1% (71.9%-79.8%) than MCDBT-1 for populations at relatively high risk of cancers, and also had ideal performance.

CONCLUSION

In this large-scale clinical validation study, MCDBT-1/2 models showed a high sensitivity, specificity, and accuracy of predicted origin in detecting six types of cancers.

[New understanding about the concept of minimally invasive endoscopic surgery--ERBEC]

As a vital component of gastroenterology and endoscopology, minimally invasive endoscopic surgery has expanded its technology from surface to depth, from inside to outside, from intraluminal to extraluminal lesions, and from organic diseases to functional diseases. This paper summarizes the experience of minimally invasive endoscopic surgery in the recent two decades, and in combination with the current development trend, puts forward understanding about the concept of minimally invasive endoscopic surgery--ERBEC, namely elements, reservation-resection, bilateral-benefit, expansion, collaboration, in order to truly benefit patients through new methods and concepts.

[Epidemiological characteristics of imported COVID-19 cases in Tianjin]

Objective: To understand the epidemiological characteristics of imported COVID-19 cases in Tianjin, and provide references for risk assessment and control of imported COVID-19 cases. Methods: The information of imported COVID-19 cases were obtained from National Notifiable Disease Report System of China CDC. The data of imported COVID-19 cases reported from Tianjin airport and epidemiological surveys by CDCs at all levels from March 15, 2020 to August 31, 2021 were collected and analyzed by using software Excel 2010, SPSS 25.0 and R. Results: From March 15, 2020 to August 31, 2021, a total of 606 imported cases of COVID-19 were reported in Tianjin, in which 552 cases were finally included in the analysis. The male to female ratio of the cases was 1.8∶1, the age of the cases ranged from 3 to 77 years, and the cases were mainly reported in age group 20-39 years (59.8%). The areas where the imported case sojourned within 14 days included Europe (242 cases, 43.8%), Africa (139 cases, 25.2%), Americas (85 cases, 15.4%) and Asia (86 cases, 15.6%). The proportion of confirmed cases in autumn and winter was relatively high. During the study period, the proportion of infected persons found in custom entry quarantine decreased, and the proportion of persons with personal health declaration and under medical isolation observation increased. The interval between entry and diagnosis of infected persons tended to increase. Conclusion: The proportion of imported COVID-19 cases detected on the first day of entry at Tianjin airport decreased, and the interval to detect the infected persons trended to increase, to which close attention must be paid.

[Analysis on cluster cases of COVID-19 in Tianjin]

Objective: To understand the characteristics of clusters of COVID-19 cases in Tianjin, and provide epidemiological evidence for the prevention and control of COVID-19. Methods: The data of all the COVID-19 cluster cases in Tianjin, reported by 22 February 2020, were collected to analyze the characteristics of different types of the clusters. Results: A total of 115 COVID-19 cases were reported in 33 clusters in Tianjin included 28 family clusters (71 cases), 1 work place cluster (10 cases), 3 transport vehicle clusters (8 cases) and 1 public place cluster (26 cases). Family clusters were caused by the cases from the working place or public place clusters. Numbers of secondary cases of family clusters was between 1 to 7, the median number was 2. The interval from onset to diagnosis for the first case was longer than those of other cases in the familial clusters (Z=-2.406, P=0.016). The median of incubation period of the public place clusters was 2 days. The intervals from onset to diagnosis were significant different among the family, working place and public place clusters (H=8.843, P=0.012), and also significant differences in onset time among the secondary cases (H=16.607, P=0.000). Conclusions: In the surveillance of COVID-19 epidemic, special attention should be paid to places where clustering are prone to occur, and the epidemiological investigation should be carried out timely to confirm the cluster. To prevent the transmission of COVID-19, the close contacts of the patients should be transferred to an assigned observation place on time for single room isolation. The awareness of COVID-19 prevention is low in some rural areas, reflected by many mass gathering activities and delayed medical care seeking after onset. It is necessary to strengthen the health education and take control measures in early period of epidemic.

[Investigation and analysis on characteristics of a cluster of COVID-19 associated with exposure in a department store in Tianjin]

Objective: To describe the epidemiological characteristics of a cluster of COVID-19 cases reported in Baodi district of Tianjin as of 18 February, 2020, which might be associated with the exposure in a local department store, and provide suggestions for prevention and control strategy development. Methods: The basic characteristics, time and area distributions, clinical manifestations, epidemiological history and transmission mode of the COVID-19 cases associated with the department store exposure were analyzed. Results: A total of 40 COVID-19 cases were associated with the department store exposure, accounting for 75.47% of the total confirmed cases (53 cases) reported in Baodi district. The cases were mainly at the age of 60 years or older (35.00%) and farmers (40.00%). The main clinical manifestations included fever (95.00%), cough (35.00%), and diarrhea (15.00%). The proportion of confirmed severe cases was 32.50%. The incidence curve showed that the incidence peak occurred on 31 January, 2020. Among the 40 cases, 6(15.00%) were department store employees, 19 (47.50%) were customers and 15 (37.50%) were close contacts (secondary cases). The first case occurred on 21 January, 2020, this case was a department store employee who had a purchasing history at whole sale markets in other provinces and cities before the onset, and 3 employees were still on duty after symptom onsets. The median of the incubation period of customer cases was 6 days, and the median of the interval between onset and medical treatment of customer cases was 7 days. Conclusion: This was a cluster epidemic of COVID-19, which might be associated with the exposure in the department store. By now, the current prevention and control measures have achieved satisfied effects.

[Analysis of selective endoscopy results during the epidemic of coronavirus disease 2019 (COVID-19)]

Objective: To explore the necessity and safety of selective endoscopy to detect gastrointestinal (GI) malignancy during the outbreak of coronavirus disease 2019 (COVID-19). Methods: A retrospective cohort study was carried out to analyze the clinical data of selective endoscopy performed at the Endoscopic Center, Zhongshan Hospital of Fudan University from February 20 to March 6, 2020. Clinical data included epidemiological questionnaire, chief complaints, endoscopic findings and biopsy pathology results, etc. All medical staff had blood test for IgM/IgG antibodies of COVID-19. Patients and their families were followed up by phone to determine whether they were infected with COVID-19. Meanwhile, the clinical data of selective endoscopy during the same period from February 20 to March 6, 2019 were collected as the control group to compare the overall results of endoscopy examinations during the epidemic and the detection rate of GI malignancy. Results: A total of 911 patients underwent endoscopy in the epidemic period group, and a total of 5746 cases in the control group, which was 6.3 times over the epidemic period group. In the epidemic period group, 544 cases received gastroscopy and 367 cases received colonoscopy, while 3433 cases received gastroscopy and 2313 cases received colonoscopy in the control group, which were both 6.3 times of epidemic period group. Gastroscopy revealed that 39 patients (7.2%) were diagnosed with upper GI malignancies in the epidemic period group and 77 patients (2.2%) in the control group with significant difference (χ(2)=40.243, P<0.001). The detection rate of gastric cancer in these two groups was 3.3% (n=18) and 1.7% (n=59) respectively with significant difference (χ(2)=6.254,P=0.012). The detection rate of esophageal cancer was 3.7% (n=20) and 0.5% (n=18) respectively with significant difference (χ(2)=49.303,P<0.001). Colonoscopy revealed that colorectal cancer was found in 32 cases (8.7%) of the epidemic period group and 88 cases (3.8%) of the control group with significant difference (χ(2)=17.888, P<0.001). During the epidemic period, no infection of medical staff was found through the blood test of IgM/IgG antibodies on COVID-19. No patient and family members were infected with COVID-19 by phone follow-up. Conclusion: Compared with the same period in 2019, the number of selective endoscopy decreases sharply during the epidemic period, while the detection rate of various GI malignant tumors increases significantly, which indicates that patients with high-risk symptoms of GI malignancies should still receive endoscopy as soon as possible. Provided strict adherence to the epidemic prevention standards formulated by the state and professional societies, it is necessary to carry out clinical diagnosis and treatment as soon as possible.

[A novel and simplified closure method for defect closure after endoscopic full-thickness resection of gastric submucosal tumors: short-term outcomes of "Shao-Mai" closure method]

Objective: To evaluate the feasibility and short-term efficacy of a novel and simplified closure method developed by our team for the defect closure after endoscopic full-thickness resection (EFTR) for gastric submucosal tumors (SMT) in the gastric wall. Methods: A prospective single-arm clinical study was used. Inclusion criteria: (1) the lesion was located in the fundus or the greater curvature of the stomach, and was confirmed to originate from the muscularis propria layer; (2) the diameter of the tumor was ≤3.5 cm, and the tumor had no extensive adhesion to the peritoneal tissues and organs in extraperitoneal cavity; (3) the tumor had no malignant features under ultrasound endoscopy; (4) the patient agreed to participate in the study; (5) patients with severe complications were excluded. Based on the above criteria, 20 patients with gastric SMT at the Endoscopy Center of Zhongshan Hospital of Fudan University from January 2015 to March 2018 were enrolled in this study, including 5 males and 15 females with mean age of 61.1 (38 to 70) years. Grasping forceps-assisted endo-loop snare ligation device which is called "Shao-Mai" method was used to close the defect site. All the patients underwent EFTR and "Shao-Mai" method to perform defect closure. After successful tumor resection by EFTR, an endo-loop was anchored onto the edge of the gastric defect with grasping forceps assistance and closed tightly. The observation indicators included tumor size, en bloc resection, operation time, postoperative complications and hospital stay. The follow-up indicators included tumor residual, local recurrence, and metachronous lesions. Results: All the 20 lesions were located in the muscularis propria with a size of 0.5-3.5 (mean 1.4) cm. Three of them were located in the greater curvature of the mid-upper gastric body, 17 were located in the fundus. The endoscopic "Shao-Mai" closure was successfully performed after EFTR in all the 20 cases. Endoscope was used uniquely through the entire process, without laparoscopic assistance. The operative time was 20-100 (mean 43.8) minutes, while the "Shao-Mai" closure procedure took a range of 3-30 (mean 10.1) minutes. The en bloc resection rate was 100%. The pathological diagnosis included 17 gastrointestinal stromal tumors and 3 leiomyomas. No major complications occurred during or after surgery. All the patients were discharged 1-11 (mean 3.1) days after operation. The wounds of all the cases were healed completely six months after operation and only scar was observed without ulcer. No residual lesion, tumor recurrence or metastasis, leakage or fistula of digestive tract were found during the follow-up period of 15-54 (median 41) months. Conclusion: The endoscopic "Shao-Mai" closure method is a simplified novel way, which is feasible, effective, and safe for closing the gastric defect after EFTR.

[Multi-center empirical study of virtual gastroscopy simulator in the examination of clinical practice skills of specialist physicians]

Objective: To study the role of virtual gastroscopy simulator in the examination of clinical practice skills of gastrointestinal specialists. Methods: A multi-center empirical study was carried out. In June 2018, ninety participants from three tertiary care teaching hospitals in China, including Zhongshan Hospital of Fudan University, Shanghai Tongji Hospital and Xiangya Hospital of Central South University, took part in the examination. Participants were selected as follows: 30 specialists without any experience of gastroscopy exams, 30 with basic knowledge (gastroscopy exams <500 cases) and 30 with good skill (gastroscopy exams ≥500 cases). These 90 students participated in this empirical study after theoretical study and simulator training. Among them, 50 (55.6%) were undergraduates, 25 (27.8%) masters, and 15 (16.7%) doctors; 42 (46.7%) were residents, 39 (43.3%) attending physicians, and 9 (10.0%) deputy chief physicians. The assessment was divided into two parts. The first part was to use the simulator (GI mentor II) for ballooning within 10 minutes, with a total score of 40 points. The second part was a complete gastroscopy exam on the simulator, including preparation before gastroscopy exam, gastroscopy exam, post - exam management and related knowledge quiz. The difficulty and discrimination of the assessment plan were evaluated by the extreme grouping method parameters (difficulty P definition: <0.3 was difficult, 0.3 to 0.7 was medium, ≥0.7 was easy; discrimination degree D definition: <0 was poor, 0 to 0.2 was medium, ≥0.2 was good), and by comparing the virtual gastroscopy assessment scores of different experience, academic, and professional title groups. The score analysis of the student group was expressed using the mastering rate (the average score divided by the total score). The data of the normal distribution was represented by (mean±SD) (range), and the data of the nonnormal distribution was represented by M (P25, P75). Kruskal-Wallis non-parametric test was used for comparison between groups. Results: The total score of 90 students was (82.9±10.9) (55.8 to 99.0), and the mastering rate was 82.9%. The overall difficulty of the first and the second parts were 0.78 and 0.76, respectively, and the difficulty level was easy. The overall discrimination of the first and the second parts were 0.70 and 0.67, respectively, and the discrimination was good. The stratified analysis was performed according to the professional title. The median score was 83.2 (75.5, 89.0) in the residents, 82.5 (71.7, 93.6) in the attending physicians, and 93.5 (88.5, 99.0) in the deputy chief physicians, and the difference was statistically significant (H=6.213, P=0.045). According to the stratification analysis of academic qualifications, the median score was 81.7 (73.0, 87.5) in participants with undergraduate degree, 91.0 (79.0, 95.0) in those with master degree and 88.0 (81.7, 93.5) in those with doctor degree, whose difference was statistically significant (H=9.233, P=0.010). The stratified analysis of the second part showed that the median scores of the "operational process" part of the low, medium and high basis group were 33.0 (30.5, 36.5), 34.0 (32.0, 36.0) and 37.0 (35.0, 37.5), respectively, whose difference was statistically significant (H=7.603, P=0.022). The median scores of the "operational process" section of the resident, attending physician, and deputy chief physician were 33.0 (30.5, 35.0) points, 36.0 (34.0, 37.5) points and 37.0 (37.0, 37.5) points, respectively, whose difference was statistically significant (H=18.563, P=0.001). Conclusions: The virtual gastroscopy simulator can reflect the true level of gastroscopy exam skills of the students. The examination questions are moderately difficult, and there is a good discrimination of the exam.

[Endoscopic minimally invasive treatment--from inside the lumen to outside the lumen, from the superficial layer to the deep layer]

Since the introduction of endoscopic submucosal dissection (ESD) in China in 2006, endoscopic minimally invasive treatment has experienced a booming development for more than 10 years, and its indications are gradually being expanded from inside the lumen to outside the lumen, from the superficial layer to the deep layer, from organic diseases to functional diseases. This article summaries the development of endoscopic minimally invasive resection in the past 10 years, from the perspective of mucosa, submucosa, muscularis, serosal and even extraluminal lesions, respectively, to introduce the role of endoscopic minimally invasive treatment. For mucosal lesions, ESD has become a first-line treatment for early gastric cancer; endoscopic treatment of colorectal lesions is still controversial in Europe and the United States, but is gradually being accepted. For submucosal tumors(SMT), the Expert Consensus for Endoscopic Diagnosis and Treatment of Submucosal Tumors in China (version 2018) was published in 2018, and the principles and related technical rules for gastrointestinal SMT have been highlighted. For serosal and even extraluminal lesions, natural orifice transluminal endoscopic surgery (NOTES) and tunnel endoscopic surgery, mainly including endoscopic myotomy (POEM) and endoscopic transmucosal tunneling tumor resection (STER), showed potential for development in preliminary studies, and showed good results in cholecystectomy, appendectomy, achalasia, gastroparesis and even extra-gastrointestinal tumor resection. This article describes the various endoscopic treatment techniques, and looks into their application prospects and future challenges.

[Hemorrhage-prevention value of second-look endoscopy after endoscopic submucosal dissection for early gastric cancer: a meta-analysis]

Objective: To use the meta-analysis in evaluating the hemorrhage-prevention value of second-look endoscopy after endoscopic submucosal dissection (ESD) for early gastric cancer. Methods: A literature search was conducted to identify all relevant studies comparing second-look endoscopy and non-second-look endoscopy after gastric ESD. The Medline/PubMed, Ovid, Elsevier ScienceDirect, EBSCO, CNKI and VIP databases were searched systematically. Literature inclusion criteria: (1) all the patients were diagnosed as early gastric cancer receiving ESD; (2) end point of the study included postoperative bleeding rate of ESD. Exclusion criteria: (1) papers of repeated research, review, comment, guideline, etc; (2) non-control study. Meta-analysis method was used to calculate a pooled odds ratio (OR) for developing post-ESD bleeding. Results: The meta-analysis showed that post-ESD bleeding was observed in 40 of 1287 patients (3.1%) without second-look endoscopy and in 40 of 968 patients (4.1%) with second- look endoscopy (OR=1.25, 95% CI: 0.79-1.98), with no significant difference between these two groups. Subgroup analysis on research method still indicated no significant difference of post-ESD bleeding between RCT group (OR=1.45,95%CI: 0.79-2.65) and non-RCT group (OR=1.02, 95%CI: 0.50-2.08) (all P>0.05). Conclusion: Based on meta analysis, second-look endoscopy can not reduce the rate of postoperative bleeding of ESD. Therefore, routine second-look endoscopy after gastric ESD may not be necessary to prevent delayed postoperative bleeding of ESD.

[The animal models using live pigs in the application and development of endoscopic submucosal dissection training]

Endoscopic submucosal dissection (ESD) is the gold standard technique for performing en bloc resection of large superficial tumors in the upper and lower gastrointestinal tract. It has not started in China until early 2006, when it was introduced at Endoscopy Center of Zhongshan Hospital. However, ESD is technically more difficult and can result in more complications, limiting its development in China. At present, reports about ESD training system in China are still not available. Therefore, our center continuously explored and gradually established structured training courses relied on the live pig model. Between 2009 and 2013, we held 23 hands-on ESD training workshops with 550 endoscopists. Questionnaires were distributed via e-mail, and there were 460 participants performing ESD in a step-up approach on the live pigs. More than one half of trainees could perform ESD with en bloc resection in the imaginary "lesion" of colon and stomach, and there were higher rates of hemorrhage and perforation occurring in colorectal ESD as compared to gastric ESD. After graduating from our hands-on workshop, up to over 90% of participants started ESD practice in their home hospitals. It was mostly provided by high-grade hospitals (IIIA) which played a major role as tertiary referral centers, covering almost all provinces and major cities in China. The training on live pig model revealed to be safe and effective as a prior step to its application in humans. It may enable novice endoscopists to acquire ESD skills and start performing ESD as soon as possible. The role of adequate training is of course to influence the spread of this technique and promote ESD development around China.

[Application value of dual channel dual curved endoscope in the endoscopic submucosal dissection for gastric angle mucosal lesions]

Objective: To evaluate the clinical value of dual channel dual curved endoscope in the endoscopic submucosal dissection (ESD) for gastric angle mucosal lesions. Methods: A descriptive cohort study was carried out. Clinicopathological data of 20 cases with gastric angle mucosal lesions undergoing ESD by dual channel dual curved endoscope in our center from October 2016 to August 2018 were collected and analyzed retrospectively. Inclusion criteria: (1) the lesion was located in the gastric angle confirmed by gastroscopy before ESD. (2) CT examination showed no distant metastasis. (3) pathological biopsy confirmed precancerous lesion or early cancerous lesion without submucosal invasion. (4) the whole operation was performed by the same endoscopist with ESD experience of about 2000 cases. Patients with previous ESD history of gastric angle and other serious diseases were excluded. The dual channel dual curved endoscopy (Olympus, GIF-2TQ260M) and other conventional endoscopic surgical instruments were used in all the cases. Complete tumor resection rate, pathological results, intraoperative and postoperative complications, operation time and hospitalization time were observed. Follow - up parameters included residual tumor, local recurrence and heterogeneous lesion. Results: Of 20 patients, 14 were male and 6 were female with an average of 55.6 years (range, 37 to 75). All the tumors located in gastric angle. Specimen size ranged from 1.2 to 5.5 (average 2.9) cm. Operation time ranged from 50 to 120 (average 85.8) minutes. Hospital stay ranged from 3 to 7 (average 5.1) days. The en bloc excision was performed successfully in all 20 cases. There was no perforation or bleeding during or after operation. Pathological results showed curative or nearly curative resection stage in all the cases. No tumor residual or recurrence was found during follow-up for 8 to 30 (average 18.5) months. Conclusion: Dual channel dual curved endoscope can provide good vision and easy control in removing the lesion completely and avoiding complications during the ESD procedure in gastric angle mucosal lesions with good long-term efficacy.

[Application of dental floss traction-assisted endoscopic submucosa dissection to rectal neuroendocrine neoplasm]

Objective: To evaluate the safety and efficacy of dental floss traction-assisted endoscopic submucosal dissection (DFS-ESD) for rectal neuroendocrine neoplasm (NEN). Methods: A retrospective cohort study was performed. Clinical data of rectal NEN patients undergoing ESD at Endoscopy Center of Zhongshan Hospital, Fudan University from January 2016 to December 2017 were retrospectively analyzed. Inclusion criteria: 1) age of 18 to 80 years old; 2) maximal diameter of lesions <1.5 cm; 3) tumor locating in the submucosa without invasion into the muscularis propria; 4) no enlarged lymph nodes around bowel and in abdominal cavity; 5) ESD requested actively by patients. A total of 37 patients were enrolled, including 23 male and 14 female cases with mean age of (56.0±11.3) years. All the lesions were single tumor of stage T1, and the mean size was 0.8±0.2(0.5-1.2) cm. Postoperative pathology revealed all samples as neuroendocrine tumors (NET). Seventeen patients received DFS-ESD treatment (DFS-ESD group) and 20 patient received conventional ESD treatment (conventional ESD group). In DFS-ESD group, after the mucosa was partly incised along the marker dots, the endoscopy was extracted, and the dental floss was tied to one arm of the metallic clip. When the endoscope was reinserted, the hemoclip was attached onto the incised mucosa; another hemoclip was attached onto normal mucosa opposite to the lesion in the same way. The submucosa was clearly exposed with the traction of dental floss and the resection could proceed. The conventional ESD group received the traditional ESD operation procedure. The operation time, modified operation time (remaining time after excluding the assembly time of dental floss traction in DFS-ESD group), en bloc resection rate, R0 resection rate, morbidity of operative complication, recurrence and metastasis were compared between two groups. Results: The average tumor size was (0.8±0.2) cm in DFS-ESD group and (0.7±0.2) cm in conventional ESD group (t=0.425, P=0.673). According to postoperative pathological grading of rectal neuroendocrine neoplasm, 13 were G1 and 4 were G2 in DFS-ESD group, while 17 cases were G1 and 3 cases were G2 in conventional ESD group without significant difference (P=0.680). There were no significant differences in baseline data between in the two groups (all P>0.05). All the basal resection margins were negative, the en bloc resection rate was 100% and the R0 resection rate was 100%. Pathological results showed tumor tissue close to the burning margin in 5 cases of conventional ESD group and in 2 cases of DFS-ESD group (P=0.416). The operation time was (17.9±6.6) minutes in conventional ESD group and (14.7±3.3) minutes in DFS-ESD group (t=1.776, P=0.084). The modified operation time of DFS-ESD group was (11.9±2.8) minutes, which was significantly shorter than (17.9±6.6) minutes in conventional ESD group (t=3.425, P=0.002). The hospital stay was (2.3±0.6) days and (2.0±0.5) days in conventional ESD group and DFS-ESD group, respectively, without significant difference (t=1.436, P=0.160). No patient was transferred to surgery, and no delayed bleeding or perforation occurred in either group. There was no recurrence or primary tumor-related death, and all the patients recovered well during a follow-up period of 14(1-24) months. Conclusion: Dental floss traction-assisted ESD for rectal neuroendocrine neoplasm can simplify operation and ensure negative basal margin.

[DNA methylation modification of BRMS1 in triple-negative breast cancer and its correlation with tumor metastasis]

Objective: To investigate the effect of methylation status of breast cancer metastasis suppressor gene 1 (BRMS1) on the expression of breast cancer and the biological behavior of cancer cells in triple-negative breast cancer (TNBC). Methods: The expression of BRMS1 in TNBC tissues and corresponding non-malignant tissues and its relationship with clinicopathological parameters were detected by immunohistochemistry. The mRNA and protein expression of BRMS1 in normal breast epithelial cells and TNBC cells were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting. The methylation specific polymerase chain reaction (MSP) was used to detect the methylation status of BRMS1 in each cell. These cells were treated with demethylated preparations (5-Aza-dC) to re-activate BRMS1 expression. Using tumor cell invasion assay to detect influence of BRMS1 demethylation on the invasion capacity of cancer cells. The data were statistically analyzed. Results: The positive expression rate of BRMS1 protein in TNBC tissues was significantly lower than that in corresponding non-malignant tissues (χ(2)= 6.635, P<0.05). The mRNA expression level of BRMS1 in patients with lymph node metastasis was significantly lower than those with no lymph node metastasis (P=0.018). The down-regulation of BRMS1 expression was related to the methylation of DNA promoter, which was statistically significant (χ(2)=14.68, P<0.05). The mRNA and protein expression of BRMS1 was also correlated with tumor size and TNM staging (P=0.000-0.003). After using 5-Aza-dC, the number of cells with invasive capacity was significantly lower than those of the control group (t=3.262-10.72, P<0.05). Conclusions: The decrease of BRMS1 expression in TNBC cells is related to the methylation of DNA. Demethylation can inhibit the invasion of breast cancer cells.

Is endoscopic sphincterotomy plus large-balloon dilation a better option than endoscopic large-balloon dilation alone in removal of large bile duct stones? A retrospective comparison study

BACKGROUND

Several comparison studies have demonstrated that endoscopic sphincterotomy (EST) combined with large-balloon dilation (LBD) may be a better option than EST alone to manage large bile duct stones. However, limited data were available to compare this combination method with LBD alone in removal of large bile duct stones.

OBJECTIVE

To compare EST plus LBD and LBD alone for the management of large bile duct stones, and analyze the outcomes of each method.

PATIENTS AND METHODS

Sixty-one patients were included in the EST plus LBD group, and 48 patients were included in the LBD alone group retrospectively. The therapeutic success, clinical characteristics, procedure-related parameters and adverse events were compared.

RESULTS

Compared with EST plus LBD, LBD alone was more frequently performed in patients with potential bleeding diathesis or anatomical changes (P = 0.021). The procedure time from successful cannulating to complete stone removal was shorter in the LBD alone group significantly (21.5 vs. 17.3 min, P = 0.041). The EST plus LBD group and the LBD alone group had similar outcomes in terms of overall complete stone removal (90.2% vs. 91.7%, P = 1.000) and complete stone removal without the need for mechanical lithotripsy (78.7% vs. 83.3%, P = 0.542). Massive bleeding occurred in one patient of the EST plus LBD group, and successfully coagulated. Postoperative pancreatitis did not differ significantly between the EST plus LBD group and the LBD alone group (4.9% vs. 6.3%; P = 1.000).

CONCLUSION

Endoscopic sphincterotomy combined with LBD offers no significant advantage over LBD alone for the removal of large bile duct stones. LBD can simplify the procedure compared with EST plus LBD in terms of shorten the procedure time.

Submucosal tunneling endoscopic resection for upper gastrointestinal multiple submucosal tumors originating from the muscular propria layer: a feasibility study

BACKGROUND AND AIMS

In recent years, submucosal tunneling endoscopic resection (STER) was applied more and more often for single gastrointestinal (GI) submucosal tumor (SMT). However, little is known about this technique for treating multiple SMTs in GI tract. In the present study, we investigated the feasibility and outcome of STER for upper GI multiple SMTs originating from the muscularis propria (MP) layer.

PATIENTS AND METHODS

A feasibility study was carried out including a consecutive cohort of 23 patients with multiple SMTs from MP layer in esophagus, cardia, and upper corpus who were treated by STER from June 2011 to June 2014. Clinicopathological, demographic, and endoscopic data were collected and analyzed.

RESULTS

All of the 49 SMTs were resected completely by STER technique. Furthermore, only one tunnel was built for multiple SMTs of each patient in this study. En bloc resection was achieved in all 49 tumors. The median size of all the resected tumors was 1.5 cm (range 0.8-3.5 cm). The pathological results showed that all the tumors were leiomyoma, and the margins of the resected specimens were negative. The median procedure time was 40 min (range: 20-75 min). Gas-related complications were of the main complications, the rates of subcutaneous emphysema and pneumomediastinum, pneumothorax, and pneumoperitoneum were 13.0%, 8.7% and 4.3%. Another common complication was thoracic effusion that occurred in 2 cases (8.7%), among which only 1 case (4.3%) with low-grade fever got the drainage. Delayed bleeding, esophageal fistula or hematocele, and infection in tunnel were not detected after the operation there were no treatment-related deaths. The median hospital stay was 4 days (range, 2-9 days). No residual or recurrent lesion was found during the follow-up period (median 18, ranging 3-36 months).

CONCLUSION

Submucosal tunneling endoscopic resection is a safe and efficient technique for treating multiple esophageal SMTs originating from MP layer, which can avoid patients suffering repeated resections.

Peroral endoscopic remyotomy for failed Heller myotomy: a prospective single-center study

BACKGROUND AND STUDY AIMS

Recurrence/persistence of symptoms occurs in approximately 20 % of patients after Heller myotomy for achalasia. Controversy exists regarding the therapy for patients in whom Heller myotomy has failed. The aim of the current study was to evaluate the efficacy and feasibility of peroral endoscopic myotomy (POEM), a new endoscopic myotomy technique, for patients with failed Heller myotomy.

PATIENTS AND METHODS

A total of 12 patients with recurrence/persistence of symptoms after Heller myotomy, as diagnosed by established methods and an Eckardt score of ≥ 4, were prospectively included. The primary outcome was symptom relief during follow-up, defined as an Eckardt score of ≤ 3. Secondary outcomes were procedure-related adverse events, lower esophageal sphincter (LES) pressure on manometry, reflux symptoms, and medication use before and after POEM.

RESULTS

All 12 patients underwent successful POEM after a mean of 11.9 years (range 2 - 38 years) from the time of the primary Heller myotomy. No serious complications related to POEM were encountered. During a mean follow-up period of 10.4 months (range 5 - 14 months), treatment success was achieved in 11/12 patients (91.7 %; mean score pre- vs. post-treatment 9.2 vs. 1.3; P < 0.001). Mean LES pressure was 29.4 mmHg pre-treatment and 13.5 mmHg post-treatment (P < 0.001). One patient developed mild reflux symptoms and required intermittent medication with proton pump inhibitors.

CONCLUSIONS

POEM seems to be a promising new treatment for failed Heller myotomy resulting in short-term symptom relief in > 90 % of cases. Previous Heller myotomy may make subsequent endoscopic remyotomy more challenging, but does not prevent successful POEM.

Correlated electrons step by step: itinerant-to-localized transition of fe impurities in free-electron metal hosts

High-resolution photoemission spectroscopy and ab initio calculations have been employed to analyze the onset and progression of d-sp hybridization in Fe impurities deposited on alkali metal films. The interplay between delocalization, mediated by the free-electron environment, and Coulomb interaction among d electrons gives rise to complex electronic configurations. The multiplet structure of a single Fe atom evolves and gradually dissolves into a quasiparticle peak near the Fermi level with increasing host electron density. The effective multiorbital impurity problem within the exact diagonalization scheme describes the whole range of hybridizations.

One-dimensional 3d electronic bands of monatomic Cu chains

The electronic structure of an array of monatomic Cu chains grown on the Pt(997) surface has been examined by angle-resolved photoemission. The monatomic wires exhibit properties associated with 3d electron confinement in one dimension. Along the wire direction, the 3d bands states display a dispersive character, with periodicity in reciprocal space defined by the wire array geometry. These observations are compared and analyzed with ab initio calculations based on the full-potential linearized augmented plane-wave method.

Simultaneous improvement for four quality traits of Zhenshan 97, an elite parent of hybrid rice, by molecular marker-assisted selection

"Zhenshan 97" is the female parent of a number of widely used hybrids for rice production in China. However, this line is of poor quality because of a high amylose content (AC), a hard gel consistency (GC) and a low gelatinization temperature (GT), together with a chalky endosperm. It had been determined that the three traits for cooking and eating quality, AC, GC and GT, are controlled by the Waxy locus and/or the tightly linked genomic region. In this study we improved the eating and cooking quality of Zhenshan 97 by introgressing the Waxy gene region from Minghui 63 (wx-MH), a restorer line, that has medium AC, soft GC and high GT. The wx-MH fragment was transferred to Zhenshan 97B by three backcrosses and one selfing, then from Zhenshan 97B to Zhenshan 97A by a cross and a backcross. Molecular marker-assisted selection was applied in the series to select for individuals carrying wx-MH, to identify recombination between the Waxy and flanking markers, and also to recover the genetic background of the recurrent parent. According to the marker genotypes, the improved versions of Zhenshan 97B and Zhenshan 97A, or Zhenshan 97B(wx-MH) and Zhenshan 97A(wx-MH), were the same as the originals except for the Waxy region of less than 6.1 cM in length. The selected lines and their hybrids with Minghui 63, or Shanyou 63(wx-MH), showed a reduced AC and an increased GC and GT, coupled with a reduced grain opacity. Field examinations of agronomic performance revealed that Zhenshan 97B(wx-MH) and Shanyou 63(wx-MH) were essentially the same as the originals except for a significant decrease in grain weight. The simultaneous improvement of AC, GA, GT and opacity, indicated that the Waxy region had major effects on the four quality traits. The improved versions of Zhenshan 97 A and B should be immediately useful in hybrid rice production.

[Improvement of transformation frequency of rice mediated by Agrobacterium]

The factors influencing the frequency of rice transformation mediated by Agrobacterium have been investigated by using 16 commercially important indica and japonica rice cultivars or lines. The main results were as following: For most rice CC medium was the best for both callus initiation and subculture. With supplement of 2.5-5 mg/L ABA the quality of calli can be improved. The concentration of selective agent for Indica rice callus was lower than that for japonica rice callus. Agrobacterium tumefaciens strain EHA105 was more efficient than LBA4404 and AGL1 for rice transformation. The inhibitive effect of cefotaxime to Agrobacterium was better than that of carbenicillin. The partial desiccation treatment after co-cultivation was beneficial to inhibit the growth of Agrobacterium and increase transformation efficiency. A stable and efficient Agrobacterium-mediated transformation system has been established in ten different rice cultivars and fertile transgenic plants have been obtained.