Robotics for Advanced Therapeutic Colonoscopy.

Although colonoscopy was originally a diagnostic imaging procedure, it has now expanded to include an increasing range of therapeutic interventions. These procedures require precise maneuvers of instruments, execution of force, efficient transmission of force from the operator to the point of application, and sufficient dexterity in the mobilization of endoscopic surgical instruments. The conventional endoscope is not designed to support technically demanding endoscopic procedures. In case of colonoscopy, the tortuous anatomy of the colon makes inserting, moving, and orientating the endoscope difficult. Exerting excessive pressure can cause looping of the endoscope, pain to the patient, and even perforation of the colon. To mitigate the technical constraints, numerous technically enhanced systems have been developed to enable better control of instruments and precise delivery of force in the execution of surgical tasks such as apposing, grasping, traction, counter-traction, and cutting of tissues. Among the recent developments are highly dexterous robotic master and slave systems, computer-assisted or robotically enhanced conventional endoscopes, and autonomously driven locomotion devices that can effortlessly traverse the colon. Developments in endoscopic instrumentations have overcome technical barriers and opened new horizons for further advancements in therapeutic interventions. This review describes examples of some of these systems in the context of their applications to advanced therapeutic colonoscopy.

Training in endoscopic ultrasonography: An Asian perspective.

Training of endoscopic ultrasonography (EUS) in Asia faces two major challenges: (i) the ever-increasing demand for skills to handle a growing range of interventional EUS procedures; and (ii) a continual shortage of EUS training programs. As the therapeutic application of EUS continues to expand, the need to train more new endosonographers and upgrade skills of existing ones has become more critical than ever before. A formal fellowship to acquire EUS knowledge and skills in an advanced endoscopy center has always been perceived as the best way of training novices, but such opportunities remain limited in most Asian countries. To keep up with the pace of development in EUS, more short-term EUS programs have been conducted across Asia in recent years. Such programs are generally intensive and may combine didactic lectures, live-case demonstrations, and hands-on training on phantoms, or live animal models for teaching. Although not as rigorous as conventional full-time EUS fellowships, such short-term programs are not necessarily inferior in quality. With courses offered from basic to advanced levels, and at regular intervals, busy practising endoscopists have the flexibility to attend the course that best matches their individual levels of experience, learn at their own pace and acquire EUS knowledge and skills over as many courses as desired. This open-ended progressive learning model is more agile than established fixed-term learning models and is expected to adapt better to future needs.

BOB CAT: A Large-Scale Review and Delphi Consensus for Management of Barrett's Esophagus With No Dysplasia, Indefinite for, or Low-Grade Dysplasia.

OBJECTIVES: Barrett's esophagus (BE) is a common premalignant lesion for which surveillance is recommended. This strategy is limited by considerable variations in clinical practice. We conducted an international, multidisciplinary, systematic search and evidence-based review of BE and provided consensus recommendations for clinical use in patients with nondysplastic, indefinite, and low-grade dysplasia (LGD). METHODS: We defined the scope, proposed statements, and searched electronic databases, yielding 20,558 publications that were screened, selected online, and formed the evidence base. We used a Delphi consensus process, with an 80% agreement threshold, using GRADE (Grading of Recommendations Assessment, Development and Evaluation) to categorize the quality of evidence and strength of recommendations. RESULTS: In total, 80% of respondents agreed with 55 of 127 statements in the final voting rounds. Population endoscopic screening is not recommended and screening should target only very high-risk cases of males aged over 60 years with chronic uncontrolled reflux. A new international definition of BE was agreed upon. For any degree of dysplasia, at least two specialist gastrointestinal (GI) pathologists are required. Risk factors for cancer include male gender, length of BE, and central obesity. Endoscopic resection should be used for visible, nodular areas. Surveillance is not recommended for <5 years of life expectancy. Management strategies for indefinite dysplasia (IND) and LGD were identified, including a de-escalation strategy for lower-risk patients and escalation to intervention with follow-up for higher-risk patients. CONCLUSIONS: In this uniquely large consensus process in gastroenterology, we made key clinical recommendations for the escalation/de-escalation of BE in clinical practice. We made strong recommendations for the prioritization of future research.

Feasibility of full-thickness gastric resection using master and slave transluminal endoscopic robot and closure by Overstitch: a preclinical study.

BACKGROUND: Gastric submucosal tumors are often treated by laparoscopic wedge resection. This study aimed to examine the feasibility of gastric full-thickness resection through a totally endoscopic approach using the master and slave transluminal endoscopic robot (MASTER), and closure of the luminal defect with an endoscopic suturing device. METHODS: The operation was performed in two live porcine models under general anesthesia. First, the anterior wall of the stomach was slung to the abdominal wall using a percutaneous suturing device. An imaginary 5-cm lesion was marked using a needle knife. After the initial mucosal incision was made using an IT knife, the MASTER was introduced through a long overtube. A circumferential mucosal incision was completed with the MASTER to expose the muscularis propria which was grasped and incised to the serosal layer by electrocautery applied through the hook of the MASTER. The full-thickness resection of the gastric wall was completed with retraction using the grasper and dissection using the hook. While the defect was being created, the luminal space was maintained with traction of the percutaneous sutures. The defect was closed with suture plication using an Apollo Overstitch device. RESULTS: Two full-thickness gastric resections were performed in two nonsurvival porcine models (body weight = 30 and 35 kg, respectively) using the MASTER. The total procedure time was 56 min for the first model and 70 min for the second model. The luminal view was maintained during the whole procedure, and there was no damage to surrounding organs throughout the whole procedure. The gastric defects were closed successfully using Overstitch, with satisfactory gastric distension and no gas leakage afterward. CONCLUSION: The current experiment demonstrated the feasibility and safety of a totally endoscopic approach for the treatment of gastric submucosal tumors: full-thickness resection with the MASTER and successful closure of the defect using Overstitch.

Current status on the diagnosis and evaluation of pancreatic tumor in Asia with particular emphasis on the role of endoscopic ultrasound.

In Asia, the incidence of pancreatic cancer in some countries has been increasing. Owing to most cases being diagnosed late, prognosis for pancreatic cancer remains dismal. It is clear that the future for pancreatic cancer lies in early detection. While the possible presence of pancreatic masses is often first raised by non-invasive abdominal imaging, such as computerized tomography and magnetic resonance imaging, smaller lesions and locoregional lymph node metastases are often not detectable by these means. Endoscopic ultrasonography (EUS) offers a higher sensitivity (93-100%) for detection of small potentially curable pancreatic masses than other existing imaging modalities. It is also recommended for the evaluation of portal vein confluence, portal vein, celiac axis, and superior mesentric artery origin, and exclusion of resectability. Due to the closer proximity of EUS to the target structure, and lower rate of needle tract seeding, EUS-guided fine-needle aspiration of pancreatic mass is considered the most suitable tissue acquisition technique. Lastly, EUS also enables the performance of endoscopic interventions. Its performance can be further enhanced with newer techniques, including contrast-enhanced ultrasound and elastrography. It is anticipated that in the near future, molecular technologies may make it possible to detect microscopic amounts of cancer in tissue or blood, predict relapse and survival after therapy, as well as determine optimal therapy.

Factors determining diagnostic yield of endoscopic ultrasound guided fine-needle aspiration for pancreatic cystic lesions: a multicentre Asian study.

BACKGROUND AND AIM: The purpose of this study was to determine (1) the diagnostic yield for endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) in patients with pancreatic cystic lesions, (2) additional value of EUS-FNA over EUS alone in the diagnosis of pancreatic cysts, and (3) diagnostic sensitivity and specificity of EUS and EUS-FNA in the subset of patients where histopathology of surgical specimens were available. METHODS: All patients who underwent EUS examination for the evaluation of pancreatic cystic lesions in six Asian centres were included in the study. RESULTS: Of 298 patients with pancreatic cysts who underwent EUS, 132 (44.3 %) underwent FNA. In the entire cohort, pseudocysts and intraductal papillary mucinous neoplasm (IPMN) were the predominant cystic lesions. The cytologic yield of EUS-FNA was 47 %. On univariate analysis, factors associated with higher cytologic yield included vascular involvement on EUS, presence of solid cystic component, and increased number of needle passes during EUS-FNA. On multivariate analysis, presence of solid cystic components and increased number of needle passes during EUS-FNA were associated with higher diagnostic yield of EUS-FNA. For pancreatic cysts with a solid component, the diagnostic yield of EUS-FNA increased significantly from 44 % with one pass to 78 % with more than one pass (p = 0.016). In the absence of a solid component, the diagnostic yield was 29 % with one pass and was not significantly different from the diagnostic yield of 50 % with more than one pass, p = 0.081. CONCLUSION: The cytologic yield of EUS-FNA was 47 %. When a solid component was present in the cyst, doing more than one pass during EUS-FNA increased its diagnostic yield.

Robot-assisted endoscopic submucosal dissection is effective in treating patients with early-stage gastric neoplasia.

BACKGROUND & AIMS: Endoscopic submucosal dissection (ESD) is a new technique for endoscopic resection of early-stage gastrointestinal cancers. Though ESD achieves high rate of en bloc resection, it is technically difficult to master. The development of a novel robotic endoscopic system that has 2 arms attached to an ordinary endoscope-Master and Slave Transluminal Endoscopic Robot (MASTER)-has improved the performance of complex endoluminal procedures. We evaluated the efficacy of MASTER-assisted ESD in treatment of patients with early-stage gastric neoplasia. METHODS: We performed a multicenter prospective study of 5 patients with early-stage gastric neoplasia, limited to the mucosa. After markings and circumferential mucosal incision, all submucosal dissections were performed using the MASTER system. We measured baseline demographics, tumor characteristics, and perioperative and clinical outcomes. RESULTS: All patients underwent successful MASTER-assisted ESD. The mean submucosal dissection time was 18.6 minutes (median, 16 minutes; range, 3-50 minutes). No perioperative complications were encountered. Three patients were discharged from the hospital within 12 hours and 2 on the third day after the procedures. Two patients were found to have intramucosal adenocarcinoma, 1 had high-grade dysplasia, 1 had low-grade dysplasia, and 1 had a hyperplastic polyp. The resection margins were clear of tumors in all 5 patients. No complications were observed at the 30-day follow-up examination. Follow-up endoscopic examinations revealed that none of the patients had residual or recurrent tumors. CONCLUSIONS: A flexible endoscopy robotic system can be used to perform ESD and effectively treat patients with early gastric neoplasia.

Current status of Barrett's esophagus research in Asia.

In Western countries, the epidemiology of esophageal cancer has changed considerably over the past decades with a rise in the ratio of adenocarcinoma to squamous cell carcinoma. Although the prevalence of gastroesophageal reflux is increasing in Asia, the prevalences of Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) have remained low in most Asian countries. The Asian Barrett's Consortium recently conducted a review of published studies on BE from Asia to assess the current status of BE research in Asia, and to recommend potential areas for future BE research in the region. Differences in study design, enrolled population, and endoscopic biopsy protocols used have led to substantial variability in the reported BE prevalence (0.06% to 19.9%) across Asia. In particular, some Japanese studies used diagnostic criteria that differed considerably from what was used in most Asian studies. As in Western countries, increased age, male sex, tobacco smoking, reflux symptoms, and erosive esophagitis have been found to be risk factors for BE in several case-control studies from Asia. The Prague C and M criteria, developed to provide better interobserver reliability in diagnosis and grading of BE, are currently under extensive evaluation in the Asian population. There is a need for standardized protocols for endoscopic and histopathologic diagnosis before initiating collaborative projects to identify etiologic determinants of BE and its ensuing malignant transformation. At present, data regarding the management and long-term outcome of BE are extremely limited in Asia. More studies of BE in this geographic area are warranted.