Endoscopic mucosal resection in the upper gastrointestinal tract

Nanocarriers for Active Ingredients of Chinese Medicine (AIFCM) Used in Gastrointestinal Cancer Therapy

Active ingredients of Chinese medicine (AIFCM) are pharmacological substances taken from traditional Chinese medicine that show promise in treating gastrointestinal cancer. Compared with traditional chemotherapeutic drugs, AIFCM have advantages such as multi-target and multi-level treatment of gastrointestinal cancer. Nanocarriers have the following advantages, better bioavailability, passive or active targeting of tumor sites and responsive release of drugs. The use of nanocarriers for delivery of AIFCM in treatment of gastrointestinal cancer, can overcome the disadvantages of some AIFCM, such as insolubility and low bioavailability. In this review, we first outline the background on gastrointestinal cancer, main curative factors and conventional therapeutic approaches. Then, the mechanisms for AIFCM in gastrointestinal cancer therapy are presented in the following four aspects: gene regulation, immune modulation, cellular pathway transduction, and alteration of intestinal flora. Thirdly, preparation of various nanocarriers and results when combining AIFCM in gastrointestinal cancer are presented. Fourth, application of novel targeted nanocarriers and responsive nanocarriers in gastrointestinal tumors is further introduced. Finally, the application of AIFCM in the treatment of gastrointestinal cancer is summarized and prospected, hoping to shed some light on the nanocarrier-bound AIFCM in the treatment of gastrointestinal cancer.

Utilization of Ultrasonic Image Characteristics Combined with Endoscopic Detection on the Basis of Artificial Intelligence Algorithm in Diagnosis of Early Upper Gastrointestinal Cancer

The aim of this study was to evaluate the diagnostic value of artificial intelligence algorithm combined with ultrasound endoscopy in early esophageal cancer and precancerous lesions by comparing the examination of conventional endoscopy and artificial intelligence algorithm combined with ultrasound endoscopy, and by comparing the real-time diagnosis of endoscopy and the ultrasonic image characteristics of artificial intelligence algorithm combined with endoscopic detection and pathological results. 120 cases were selected. According to the inclusion and exclusion criteria, 80 patients who met the criteria were selected and randomly divided into two groups: endoscopic examination combined with ultrasound imaging based on intelligent algorithm processing (cascade region-convolutional neural network (Cascade RCNN) model algorithm group) and simple use of endoscopy group (control group). This study shows that the ultrasonic image of artificial intelligence algorithm is effective, and the detection performance is better than that of endoscopic detection. The results are close to the gold standard of doctor recognition, and the detection time is greatly shortened, and the recognition time is shortened by 71 frames per second. Compared with the traditional convolutional neural network (CNN) algorithm, the accuracy and recall of image analysis and segmentation using feature pyramid network are increased. The detection rates of CNN model, Cascade RCNN model, and endoscopic detection alone in early esophageal cancer and precancerous lesions are 56.3% (45/80), 88.8% (71/80), and 44.1% (35/80), respectively. The detection rate of Cascade RCNN model and CNN model was higher than that of endoscopy alone, and the difference was statistically significant (P < 0.05). The sensitivity, specificity, positive predictive value, and negative predictive value of Cascade RCNN model were higher than those of CNN model, which was close to the gold standard for physician identification. This provided a reference basis for endoscopic ultrasound identification of early upper gastrointestinal cancer or other gastrointestinal cancers.

Novel Transgastric Endoluminal Segmental Esophagectomy and Primary Anastomosis Technique: A Hybrid Transgastric Thoracoscopic Esophagectomy for the Treatment of High Grade Dysplasia and Early Esophageal Cancer in a Porcine Ex vivo Model

Multiple modalities are currently employed in the treatment of high grade dysplasia and early esophageal carcinoma. While they are the subject of ongoing investigation, surgery remains the definitive modality for oncological resection. Esophagectomy, however, is traditionally a challenging surgical procedure and carries a significant incidence of morbidity and mortality. Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are considerably less invasive alternatives to esophagectomy in the diagnosis and treatment of high grade dysplasia, early esophageal squamous cell carcinoma and adenocarcinoma. However, many early esophageal cancer patients, with favorable histology, who could benefit from endoscopic resection, are referred for formal esophagectomy due to lesion characteristics such as unfavorable lesion morphology or recurrence after previous endoscopic resection. In this study we present a novel, hybrid thoracoscopic transgastric endoluminal segmental esophagectomy with primary anastomosis for the potential treatment of high grade dysplasia and early esophageal cancer in a porcine ex vivo model as a proposed bridge between endoscopic resection and the relatively high mortality and morbidity formal esophagectomy procedure. The novel technique consists of thoracoscopic esophageal mobilization in addition to transgastric endoluminal segmental esophagectomy and anastomosis utilizing a standard circular stapler. The technique was found feasible in all experimental subjects. The minimally invasive nature of this novel procedure as well as the utility of basic surgical equipment and surgical skill is an important attribute of this method and can potentially make it a treatment option for many patients who would otherwise be referred for a formal esophagectomy.

First case of paralytic ileus after endoscopic mucosal resection of caecal polyp

Endoscopic mucosal resection (EMR) is a technique developed for the removal of sessile or flat neoplastic lesions confined to the superficial layers (mucosa and submucosa) of the gastrointestinal tract. Bleeding and perforation are well-known complications of EMR. Here we report the first case of paralytic ileus after EMR of a caecal polyp. A 66-year-old man was scheduled for elective EMR of a 3.5-cm caecal polyp under general anaesthesia after a screening colonoscopy. The procedure was performed by an expert endoscopist, and air was insufflated during the procedure because of the unavailability of CO₂. The polyp was successfully removed; the procedure duration was 81 min. After the procedure, the patient complained of abdominal pain and dyspnoea. He developed tachypnoea and tachycardia as well as oxygen desaturation with SpO₂ 84%. He was administered oxygen therapy via a non-rebreather mask, following which his oxygenation improved. His abdominal X-ray findings were consistent with ileus. Therefore, a nasogastric tube was placed, and the patient was admitted to our hospital. He was managed conservatively and underwent serial abdominal X-rays that showed improvement of the ileus. On the fourth day of admission, he was started on an oral diet; on the sixth day of admission, he was discharged with resolving ileus. Computed tomography enterography performed 1 week after discharge showed complete resolution of the ileus. Factors that may have contributed to the occurrence of ileus in our patient include the use of air during the procedure, location of the polyp (caecal), duration of the procedure, effect of electrocautery, use of general anaesthesia and possibility of aspiration pneumonitis. This case report will make endoscopists aware of the abovementioned factors while performing EMR as this procedure can lead to the complication of paralytic ileus with significant patient morbidity. Conservative treatment should be attempted first before any other intervention.

Multiband mucosectomy for advanced dysplastic lesions in the upper digestive tract

Endoscopic resection (ER) is at present an accepted treatment for superficial gastrointestinal neoplasia. ER provides similar efficacy to surgery; however, it is minimally invasive and less expensive. Endoscopic mucosal resection (EMR) is superior to biopsy for diagnosing advanced dysplasia and can change the diagnostic grade and the management. Several EMR techniques have been described that are alternatively used dependent upon the endoscopist personal experience, the anatomic conditions and the endoscopic appearance of the lesion to be resected. The literature suggests that EMR offers comparable outcomes to surgery for selected indications. EMR techniques using a cap fitted endoscope and EMR using a ligation device [multiband mucosectomy (MBM)] are the most frequently use. MBM technique does not require submucosal injection as with the endoscopic resection-cap technique, multiple resections can be performed with the same snare, pre-looping the endoscopic resection-snare in the ridge of the cap is not necessary, MBM does not require withdrawal of the endoscope between resections and up to six consecutive resections can be performed. This reduces the time and cost required for the procedure, while also reducing patient discomfort. Despite the increasing popularity of MBM, data on the safety and efficacy of this technique in upper gastrointestinal lesions with advanced dysplasia, defined as those lesions that have high-grade dysplasia or early cancer, is limited.

When to puncture, when not to puncture: Submucosal tumors

Subepithelial masses of the gastrointestinal (GI) tract are a frequent source of referral for endosonographic evaluation. Subepithelial tumors most often appear as protuberances in the GI tract with normal overlying mucosa. When there is a need to obtain a sample of the mass for diagnosis, endoscopic ultrasound (EUS) - guided fine-needle aspiration (FNA) is superior to other studies and should be the first choice to investigate any subepithelial lesion. When the decision is made to perform EUS-guided FNA several technical factors must be considered. The type and size of the needle chosen can affect diagnostic accuracy, adequacy of sample size and number of passes needed. The use of a stylet or suction and a fanning or standard technique during EUS-guided FNA are other factors that must be considered. Another method proposed to improve the efficacy of EUS-guided FNA is having an on-site cytopathologist or cytotechnician. Large or well-differentiated tumors may be more difficult to diagnose by standard EUS-FNA and the use of a biopsy needle can be used to acquire a histopathology sample. This can allow preservation of tissue architecture and cellularity of the lesion and may lead to a more definitive diagnosis. Alternatives to FNA such as taking bite-on-bite samples and endoscopic submucosal resection (ESMR) have been studied. Comparison of these two techniques found that ESMR has a significantly higher diagnostic yield. Most complications associated with EUS-FNA such as perforation, infection and pancreatitis are rare and the severity and incidence of these adverse events is not known. Controversy exists as to the optimal method in which to perform EUS-FNA and larger prospective trials are needed.

Approach to rectal cancer surgery

Rectal cancer is a distinct subset of colorectal cancer where specialized disease-specific management of the primary tumor is required. There have been significant developments in rectal cancer surgery at all stages of disease in particular the introduction of local excision strategies for preinvasive and early cancers, standardized total mesorectal excision for resectable cancers incorporating preoperative short- or long-course chemoradiation to the multimodality sequencing of treatment. Laparoscopic surgery is also increasingly being adopted as the standard rectal cancer surgery approach following expertise of colorectal surgeons in minimally invasive surgery gained from laparoscopic colon resections. In locally advanced and metastatic disease, combining chemoradiation with radical surgery may achieve total eradication of disease and disease control in the pelvis. Evidence for resection of metastases to the liver and lung have been extensively reported in the literature. The role of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for peritoneal metastases is showing promise in achieving locoregional control of peritoneal dissemination. This paper summarizes the recent developments in approaches to rectal cancer surgery at all these time points of the disease natural history.

Programmed cell death 4 nuclear loss and miR-21 or activated Akt overexpression in esophageal squamous cell carcinogenesis

The programmed cell death 4 (PDCD4) tumor suppressor is down-regulated in several malignancies, and the (subcellular) expression of its protein product is modulated by both oncomiR miR-21 and protein kinase B (Akt). PDCD4 and activated Akt (phosphorylated Akt [pAkt]) expression were assessed immunohistochemically in 53 tissue samples obtained from 25 endoscopic esophageal mucosal resections performed for squamous intraepithelial neoplasia (IEN) or squamous intramucosal carcinoma (IM-SSC). In total, 33 IEN (low-grade = 15; high-grade = 15) and 20 IM-SSC specimens were considered; 50 additional tissue samples of histologically proven normal esophageal mucosa were considered as normal controls. To further validate the results achieved, miR-21 expression (as assessed by quantitative real-time polymerase chain reaction and in situ hybridization) was tested in another series of 15 normal esophageal tissue samples, 15 high-grade IEN, and 15 IM-SCCs. Normal suprabasal squamous epithelial layers consistently featured strong PDCD4 nuclear immunostaining, which was significantly lower (P < 0.001) in IEN (both low-and high-grade) and in IM-SSC. Conversely, pAkt and miR-21 expression was significantly up-regulated in the whole spectrum of preneoplastic/neoplastic lesions considered. PDCD4 down-regulation, as assessed by immunohistochemistry, is a reliable biomarker of early-stage squamous cell esophageal neoplasia, providing additional information in the histological assessment of these lesions.

Endoscopic ultrasonography-guided diagnosis of subepithelial tumors

Subepithelial lesions are frequently discovered during routine endoscopic examinations. These lesions represent a wide spectrum of heterogeneous benign to malignant conditions. Most of these lesions are asymptomatic. There is no consensus regarding how to manage these lesions. Over the last 2 decades, the approach to these lesions has significantly improved owing to the introduction of endoscopic ultrasonography, fine-needle aspiration, immunohistochemical staining methods, and different treatment options. This article discusses the nature of subepithelial lesions, focusing on the most recent developments that use endoscopic ultrasonography to diagnose and manage these lesions.

Gastric cancer surgery: an American perspective on the current options and standards

Gastric cancer is prevalent globally, particularly in Asian countries such as Japan and Korea. While the prevalence of gastric cancer is not nearly as high in the United States (U.S.) as in Asia, the treatment armamentarium differs widely between regions. The role of surgery for gastric cancer in the U.S. has changed drastically over the last decade. While the natural history of gastric cancer seen in the U.S. markedly differs from that seen in Asia, the U.S. experience with endoscopic and minimally invasive techniques is beginning to parallel those seen in Japan and Korea. Minimally invasive surgery has truly come into the forefront of our surgical armamentarium, and its role, along with robotic and endoscopic approaches, remains to be defined as standard of care. At present, minimally invasive approaches appear to offer oncologically equivalent outcomes compared with standard open gastrectomy when performed by experienced surgeons. Extended lymphadenectomy does not appear to offer benefit with improved survival in our patient population, although sufficient lymph node sampling is imperative for adequate staging. Despite aggressive approaches to surgical resection for cure, the U.S. population tends to present with more advanced disease and have a worse prognosis than our Asian counterparts. Palliation with resection and possibly stent placement should be offered for improved quality of life in late-stage disease.

Biopsy forceps polypectomy for diminutive polypoid lesions of the upper gastrointestinal tract: an analysis of 56 cases

AIM: To evaluate the efficacy and safety of biopsy forceps polypectomy in the management of diminutive polypoid lesions of the upper gastrointestinal tract.

METHODS: The gastroscopic data for 91 cases of upper gastrointestinal polypoid lesions which were removed by biopsy forceps polypectomy (diameter ≤ 0.5 cm) or by high frequency electric resection (diameter ≤ 2.0 cm) at our hospital from 2000 to 2009 were retrospectively reviewed to compare the rates of complications and recurrence between the two groups of patients.

RESULTS: Of 56 patients undergoing biopsy forceps polypectomy, 48 had single polypoid lesion and 8 had multiple lesions. Of 35 patients undergoing high frequency electric resection, 23 had single polypoid lesion and 12 had multiple lesions. No upper gastrointestinal bleeding, perforation or other complications occurred in all cases. At six-month follow-up, a case of relapse occurred in the site of previous lesion in each group, and there was no significant difference in the recurrence rate between the two groups (1.5% vs 1.9%, P < 0.05).

CONCLUSION: There were no significant differences in therapy effectiveness and complications between biopsy forceps polypectomy and high frequency electric resection in the removal of diminutive polypoid lesions of the upper gastrointestinal tract.

Feasibility of salvage endoscopic mucosal resection by using a cap for remnant rectal carcinoids after primary EMR

BACKGROUND

Secondary endoscopic treatment for remnant lesions of rectal carcinoid tumors after primary EMR or polypectomy is technically difficult because of fibrosis of residual tissues. EMR by using a cap (EMR-C), a method to resect the submucosal layer by suction by using a transparent cap, may be feasible as a salvage treatment.

OBJECTIVE

To assess the feasibility of salvage EMR-C.

DESIGN

Retrospective analysis.

SETTING

Tertiary academic health care system.

PATIENTS

Thirty-one patients who were referred for salvage treatment of a failed en bloc excision of rectal carcinoid tumors after primary EMR or polypectomy between January 2007 and December 2009.

INTERVENTIONS

Salvage EMR-C for remnant carcinoid tumors in the rectum.

MAIN OUTCOME MEASUREMENTS

Rate of complete resection, complications, length of procedure, and recurrence rate.

RESULTS

The mean age of the patients was 52.0±11.8 years (range 30-78 years). The mean tumor size was 8.9±3.2 mm (range 5.0-13.0 mm). The mean procedure time was 9.1±3.7 minutes, and clear resection margins were pathologically confirmed in all 31 patients. The most common complication of salvage EMR-C was bleeding (7 patients, 22.6%), which was successfully treated by hemoclipping in all cases. The 1-year follow-up colonoscopy and CT results for all patients were negative for recurrence.

LIMITATIONS

Retrospective design and limited cases at a single center.

CONCLUSIONS

EMR-C is a feasible salvage therapeutic option for failed en bloc excision after primary endoscopic treatment of rectal carcinoid tumors.

Clinical significance of the discrepancy between preoperative and postoperative diagnoses in gastric cancer patients

BACKGROUND

Discrepancies between pre- and postoperative diagnoses can lead to dilemma for operative management adequacy.

PATIENTS AND METHODS

A total of 2,910 patients with gastric adenocarcinoma underwent curative surgery at the Samsung Medical Center between 2001 and 2003. Patients were divided into four groups: early gastric cancer (EGC)-EGC group that consisted of subjects who were diagnosed as having EGC pre- and postoperatively, advanced gastric cancer (AGC)-EGC group, EGC-AGC group, and AGC-AGC group. Clinicopathologic features and survival rates of groups were analyzed retrospectively.

RESULTS

Of the 2,910 patients, 1,491 (51.2%) patients were included in the EGC-EGC group, 132 (4.5%) in the AGC-EGC group, 120 (4.1%) in the EGC-AGC group, and 1,167 (40.1%) in the AGC-AGC group. The EGC-AGC group showed higher proportions of the followings than the EGC-EGC group: upper-third and middle-third tumor localizations, a tumor size from 2 to 5 cm, undifferentiated adenocarcinoma, Lauren's diffuse type, endolymphatic invasion, vascular invasion, and perineural invasion. Five-year survival rates were dependent on the final pathologic stages, not on the preoperative stages. Multivariate analysis revealed that age and American Joint Committee of Cancer stage were independent prognostic factors of patient survival.

CONCLUSION

A decision regarding minimally invasive treatment for EGC must be made having considered tumor location, size, and cellular differentiation, because of the possibility of an incorrect preoperative diagnosis.

Transoral endoscopic inner layer esophagectomy: management of high-grade dysplasia and superficial cancer with organ preservation

INTRODUCTION

Limitations of endoscopic therapies for Barrett's esophagus and superficial cancer include a compromised histological assessment, the need for surveillance, subsequent procedures, and stricture formation. Circumferential en bloc resection of the mucosa-submucosa complex followed by deployment of a biologic scaffold onto the remaining muscularis propria may address these concerns. The objective of this study was to determine technical feasibility of transoral resection of the esophageal lining.

MATERIALS AND METHODS

Transoral endoscopic inner layer esophagectomy was performed in ten swine. Endpoints included procedure duration, hemorrhage, number of perforations, and adequacy of resection length and depth.

RESULTS

Procedures were successfully completed in all animals without perioperative mortality. Procedure times averaged 179 min (range 125-320). No perforations were found, and a mean of 1.7 (0-4) interventions for hemorrhage was required. Complete longitudinal resection was achieved in nine of ten animals. Resection depth included all mucosal layers in 100% of tissue sections, the submucosal layers, SM1 in 100%, and SM2 in 96%. A portion of SM3 was adherent to the muscularis propria in 70%.

CONCLUSION

Transoral endoscopic resection of the inner esophageal layers was feasible and reproducible. This technique may facilitate a single-step definitive treatment and staging tool for early neoplastic lesions, obviating the need for esophagectomy.

Gastric oncology: an update

PURPOSE OF REVIEW

As the field of endoscopy progresses, new tools and techniques continue to be developed for gastroenterology in general and gastrointestinal oncology in particular. Some of these include enhancements in diagnostic optics such as chromoendoscopy, magnification endoscopy, and confocal laser endomicroscopy. Others include advanced therapeutics such as endoscopic mucosal resection and endoscopic submucosal dissection. In this review, we will update the reader on these latest of technologies, their benefits and risks, as well as their role in evaluating, staging, and treating gastric neoplasms, especially gastric adenocarcinoma, gastrointestinal stromal tumors, and primary gastric lymphoma.

RECENT FINDINGS

Noteworthy studies in this review indicate that in properly selected patients with gastric adenocarcinoma, endoscopic submucosal dissection is a viable alternative to gastric resection with 100% 5-year survival rates; in patients with metastatic gastrointestinal stromal tumors, imatinib can provide effective treatment with reasonable outcome; and in patients with low grade mucosa-associated lymphoid tissue lymphoma, eradication therapy with antibiotics is curative with a very low recurrence rate.

SUMMARY

The advances discussed in this review have significantly improved the care we can offer our patients in gastric oncology. With continued advancement in the field, it will be crucial to continue to study outcomes and safety of these techniques and to develop structured training for those looking to perform these procedures.

Treatment of Barrett's esophagus with high-grade dysplasia

The incidence of esophageal adenocarcinoma is increasing in the USA, now accounting for at least 4% of US cancer-related deaths. Barrett's esophagus is the main risk factor for the development of esophageal adenocarcinoma. The annual incidence of development of adenocarcinoma in Barrett's esophagus is approximately 0.5% per year, representing at least a 30-40-fold increase in risk from the general population. High-grade dysplasia is known to be the most important risk factor for progression to adenocarcinoma. Traditionally, esophagectomy has been the standard treatment for Barrett's esophagus with high-grade dysplasia. This practice is supported by studies revealing unexpected adenocarcinoma in 29-50% of esophageal resection specimens for high-grade dysplasia. In addition, esophagectomy employed prior to tumor invasion of the muscularis mucosa results in 5-year survival rates in excess of 80%. Although esophagectomy can result in improved survival rates for early-stage cancer, it is accompanied by significant morbidity and mortality. Recently, more accurate methods of surveillance and advances in endoscopic therapies have allowed scientists and clinicians to develop treatment strategies with lower morbidity for high-grade dysplasia. Early data suggests that carefully selected patients with high-grade dysplasia can be managed safely with endoscopic therapy, with outcomes comparable to surgery, but with less morbidity. This is an especially attractive approach for patients that either cannot tolerate or decline surgical esophagectomy. For patients that are surgical candidates, high-volume centers have demonstrated improved morbidity and mortality rates for esophagectomy. The addition of laparoscopic esophagectomy adds a less invasive surgical resection to the treatment armanentarium. Esophagectomy will remain the gold-standard treatment of Barrett's esophagus with high-grade dysplasia until clinical research validates the role of endoscopic therapies. Current treatment strategies for Barrett's esophagus with high-grade dysplasia will be reviewed.

Effects of anatomical position on esophageal transit time: A biomagnetic diagnostic technique

AIM: To study the esophageal transit time (ETT) and compare its mean value among three anatomical inclinations of the body; and to analyze the correlation of ETT to body mass index (BMI).

METHODS: A biomagnetic technique was implemented to perform this study: (1) The transit time of a magnetic marker (MM) through the esophagus was measured using two fluxgate sensors placed over the chest of 14 healthy subjects; (2) the ETT was assessed in three anatomical positions (at upright, fowler, and supine positions; 90º, 45º and 0º, respectively).

RESULTS: ANOVA and Tuckey post-hoc tests demonstrated significant differences between ETT mean of the different positions. The ETT means were 5.2 ± 1.1 s, 6.1 ± 1.5 s, and 23.6 ± 9.2 s for 90º, 45º and 0º, respectively. Pearson correlation results were r = -0.716 and P < 0.001 by subjects’ anatomical position, and r = -0.024 and P > 0.05 according the subject’s BMI.

CONCLUSION: We demonstrated that using this biomagnetic technique, it is possible to measure the ETT and the effects of the anatomical position on the ETT.