Novel miniature transendoscopic telerobotic system for endoscopic submucosal dissection (with videos).

BACKGROUND AND AIMS: The lack of tissue traction and instrument dexterity to allow for adequate visualization and effective dissection were the main issues in performing endoscopic submucosal dissection (ESD). Robot-assisted systems may provide advantages. In this study we developed a novel transendoscopic telerobotic system and evaluated its performance in ESD. METHODS: A miniature dual-arm robotic endoscopic assistant for minimally invasive surgery (DREAMS) was developed. The DREAMS system contained the current smallest robotic ESD instruments and was compatible with the commercially available dual-channel endoscope. After the system was established, a prospective randomized controlled study was conducted to validate the performance of the DREAMS-assisted ESD in terms of efficacy, safety, and workload by comparing it with the conventional technique. RESULTS: Two robotic instruments can achieve safe collaboration and provide sufficient visualization and efficient dissection during ESD. Forty ESDs in the stomach and esophagus of 8 pigs were completed by DREAMS-assisted ESD or conventional ESD. Submucosal dissection time was comparable between the 2 techniques, but DREAMS-assisted ESD demonstrated a significantly lower muscular injury rate (15% vs 50%, P = .018) and workload scores (22.30 vs 32.45, P < .001). In the subgroup analysis of esophageal ESD, DREAMS-assisted ESD showed significantly improved submucosal dissection time (6.45 vs 16.37 minutes, P = .002), muscular injury rate (25% vs 87.5%, P = .041), and workload (21.13 vs 40.63, P = .001). CONCLUSIONS: We developed a novel transendoscopic telerobotic system, named DREAMS. The safety profile and technical feasibility of ESD were significantly improved with the assistance of the DREAMS system, especially in the narrower esophageal lumen.

Pseudo-submucosal tumor in the colon: seeing is believing

A 65-year-old woman was admitted to our hospital with complaints of lower abdominal pain. Her physical examination was unremarkable. The results of routine laboratory testing were within the normal limits. In addition, abdominal CT was normal. Colonoscopy showed a cecum submucosal tumor with a pale yellow surface. Endoscopic ultrasound revealed homogeneous hypoechoic lesions originated from submucosal layer. ESD was subsequently performed to remove the submucosal lesion. During the ESD procedure, fecal outflowed from appendix opening . Yellow fecal-like material was visible after submucosal incision. The trap electrocut surface uplift showed more fecal attachment on the lamina propria surface, and myolayer integrity after clean the fecal (Fig1c), The final pathology of the surface bulge suggested hyperplasia (Fig1d). Patients were discharged with relieved lower abdominal pain. The final diagnosis was submucosal fecalith mimicking a submucosal tumor, eventually leads to chronic appendicitis. Common causes of cecal submucosal tumor include neuroendocrine tumors, lipomas, etc. There was few report about fecalith mimicking a submucosal tumor. ERTA is currently an effective endoscopic method for treating appendicitis combined with fecalith blockage. To our knowledge, this is the first report on a case of cecum submucosal fecalith mimicking a submucosal tumor and was successfully removed using endoscopy. (AU)

A novel modified endoscopic method for treating patients with refractory gastro-esophageal disease and moderate hiatus hernia

Background and aim: endoscopic anti-reflux mucosectomy (ARMS) is effective for patients with refractory gastroesophageal reflux disease (rGERD) with small hiatus hernia. However, evidence of its applicability in patients with larger hernia sac is lacking. This study aimed to evaluate the efficiency and safety of ARMS for patients with rGERD with moderate hiatus hernia (3-5 cm) and determine the appropriate resection range. Methods: thirty-six patients with rGERD with moderate hiatus hernia were enrolled. They were divided into 2/3 and 3/4 circumferential mucosal resection groups. The patients received modified ARMS. The gastroesophageal reflux disease questionnaire (GERD-Q) and DeMeester scores, endoscopy, 24-h pH monitoring results and lower esophageal sphincter (LES) resting pressure were compared pre- and post-procedure. Therapeutic effects and complications of the two mucosal resection ranges were analyzed. Results: thirty-six patients were enrolled in this study, all of whom had undergone ARMS surgery with at least six-month follow-up. In the 2/3 circumferential mucosal resection group, the GERD-Q score, acid exposure time (AET) and DeMeester score improved significantly compared with those before surgery (p < 0.001). In the 3/4 circumferential mucosal resection group, the GERD-Q score, AET and DeMeeter score worsened after six months (p < 0.001), but there was no difference between the two groups (p > 0.05). In both groups, there was no significant improvement in the ratio of esophagitis grade C/D and LES resting pressure after treatment compared with the baseline values (p > 0.05), and no postoperative bleeding or perforation was observed. The incidence of postoperative esophageal stenosis in the 2/3 circumferential mucosal resection group was lower than that in the 3/4 circumferential mucosal resection group (p = 0.041). (AU)

Use of a novel endoscopic overtube with bilateral tool channels for endoscopic resection of experimental lesions and repair of intestinal defects in the right colon: preclinical trial.

BACKGROUND: Endoscopic tumor resection and intestinal defect repair are technically challenging leading to invasive surgery and colectomy performed for resection of benign polyps. In this study, we evaluated the use of an endoscopic overtube with bilateral tool channels for these procedures. METHODS: Using a fresh porcine colorectum in a 3D ex vivo model, 3 cm lesions at the posterior wall of the transverse colon were removed by two different techniques: standard endoscopic submucosal dissection (ESD) technique (STD, n = 12) and ESD using the overtube with an endoscopic snare and grasper through the bilateral channels (OT, n = 12). Procedure times and the number of muscular injuries were evaluated. Using the same model, 5-10 mm full-thickness perforations within a 3 cm mucosal defect at the posterior wall of the transverse colon were closed by two different techniques: standard endoscopic closure technique (STD, n = 12) and endoscopic closure using the overtube with two graspers (OT, n = 12). The outcomes measured included bursting pressure and the number of endoscopic clips used for closure. RESULTS: Endoscopic resection of lesions was performed by the OT group in a significantly shorter total procedure time (STD vs. OT = median 38.9 min vs. 17.3, p < 0.001) and with fewer muscular injuries (median 0 vs. 2, p = 0.002), compared with the STD group. After repair of intestinal defects, the OT group showed higher median bursting pressures (STD vs. OT = 11.2 mmHg vs. 57.1, p = 0.008) despite using fewer clips (median 13 vs. 10, p < 0.001). CONCLUSION: This study demonstrates a novel traction technique with an endoscopic overtube using multiple instruments to remove lesions and repair intestinal defects in the colon more effectively. This endoscopic platform could provide a safe alternative to invasive surgical treatment.

Lowering the setting value of the esophageal endoscopic submucosal dissection device enabled tissue damage control in vitro porcine model.

One of the complications of esophageal endoscopic submucosal dissection (ESD) is postoperative stricture formation. Stenosis formation is associated with inflammation and fibrosis in the healing process. We hypothesized that the degree of thermal damage caused by the device is related to stricture formation. We aimed to reveal the relationship between thermal damage and setting value of the device. We energized a resected porcine esophagus using the ESD device (Flush Knife 1.5). We performed 10 energization points for 1 s, 3 s, and 5 s at four setting values of the device. We measured the amount of current flowing to the conducted points and the temperature and evaluated the effects of thermal damage pathologically. As results, the mean highest temperatures for 1 s were I (SWIFT Effect3 Wat20): 61.19 °C, II (SWIFT Effect3 Wat30): 77.28 °C, III (SWIFT Effect4 Wat20): 94.50 °C, and IV (SWIFT Effect4 Wat30): 94.29 °C. The mean heat denaturation areas were I: 0.84 mm2, II: 1.00 mm2, III: 1.91 mm2, and IV: 1.54 mm2. The mean highest temperature and mean heat denaturation area were significantly correlated (P < 0.001). In conclusion, Low-current ESD can suppress the actual temperature and thermal damage in the ESD wound.

Endoscopic instruments and techniques in endoscopic submucosal dissection for early gastric cancer.

Introduction: Endoscopic submucosal dissection (ESD) is a less invasive local treatment for early gastric cancer (EGC).Areas covered: Japanese guidelines have recently expanded the endoscopic treatment indications for EGC. ESD is sometimes performed for lesions with a relative indication that has not previously been considered for ESD. ESD procedures are technically difficult, especially for larger and more invasive lesions. Complete resection and accurate histological assessment of EGC lesions are essential to evaluate endoscopic curability. Various endoscopic instruments, including three types of endoscopic knives and specific hemostatic forceps, have been developed, and endoscopic techniques, including the traction method, have been modified to simplify the procedure.Expert opinion: An insulated-tip knife with large tissue contact allows us to perform faster incisions, while a needle-type knife with minimal tissue contact allows us to perform precise incisions. Furthermore, a scissor-type knife with grasping tissues allows us to perform more secure incision. The traction method enables the operator to proceed with submucosal dissection procedures. In cases with small lesions, snaring can be used, as well as knife dissection. Understanding the features of each endoscopic instrument and technique is essential because appropriate selection and usage contribute to successful and safe ESD procedures.

Prophylactic clipping after endoscopic mucosal resection of large nonpedunculated colorectal lesions: A meta-analysis.

BACKGROUND AND AIM: It is not clear whether prophylactic clipping after endoscopic mucosal resection (EMR) of large nonpedunculated colorectal lesions (LNPCLs) prevents delayed bleeding (DB). We aimed to conduct a meta-analysis to clarify the efficacy of prophylactic clipping in prevention of DB following EMR of LNPCLs. METHODS: We searched PubMed, EMBASE, Web of Science, ScienceDirect, Cochrane Library databases, and ClinicalTrials.gov for studies that compared clipping versus (vs) nonclipping in prevention of DB following EMR of LNPCLs. Pooled odds ratio (OR) was determined using a random effects model. The pooled ORs of DB, perforation, and post-polypectomy syndrome in the clipping group compared with the nonclipping group comprised the outcomes. Subgroup analyses based on study design, polyp location, and completeness of wound closure were performed. RESULTS: Five studies with a total of 3112 LNPCLs were extracted. Prophylactic clipping reduced the risk of DB compared with nonclipping (3.3% vs 6.2%, OR: 0.494, P = 0.002) following EMR of LNPCLs. In subgroup analysis, prophylactic clipping reduced DB of LNPCLs at proximal location (3.8% vs 9.8%, P = 0.029), but not of them at distal location (P = 0.830). Complete wound closure showed superior efficacy to prevent DB compared with partial closure (2.0% vs 5.4%, P = 0.004). No benefit of clipping for preventing perforation or post-polypectomy syndrome was observed (P = 0.301 and 0.988, respectively). CONCLUSIONS: Prophylactic clipping can reduce DB following EMR of LNPCLs at proximal location. Besides, complete wound closure showed superior efficacy to prevent DB compared with partial closure. Further cost analyses should be conducted to implement the most cost-effective strategies.

Snare Tip Is an Alternative Tool for Colorectal Endoscopic Submucosal Dissection.

BACKGROUND: Colorectal endoscopic submucosal dissection is typically performed by specialized knife, such as a dual knife. However, it is not covered by Taiwan's National Health Insurance. In the literature review, using a traditional snare tip for endoscopic submucosal dissection has been reported for stomach lesions only. OBJECTIVE: The purpose of this study was to evaluate the outcomes of colorectal endoscopic submucosal dissection using a snare tip. DESIGN: We retrospectively reviewed the clinical using of a snare tip compared with a dual knife for colorectal endoscopic submucosal dissection. Postoperative short- and long-term outcomes were investigated after the procedure. SETTINGS: This study was conducted at a single tertiary care institution. PATIENTS: Patients who could not afford the expense of a specialized knife were included. MAIN OUTCOME MEASURES: Dissection time, dissection speed, and perioperative complications were used for short-term outcome measurement. Recurrence-free rate was used for long-term outcome measurement. RESULTS: Twenty-one lesions were in the snare tip group and 57 lesions in the dual knife group. The outcomes, including rate of en bloc resection, complication, local recurrence, and recurrence-free interval, between the 2 groups were similar. The mean resected specimen diameter in the dual knife group is larger than the snare tip group (p = 0.041). The dissection time of the snare tip group was shorter than the dual knife group (p = 0.025). However, the dissection speed was significantly slower in the snare tip group than in the dual knife group (p = 0.008). LIMITATIONS: This study was a retrospective and single doctor chart review in nature with a limited patient number. CONCLUSIONS: The snare tip is an alternative tool for colorectal endoscopic submucosal dissection in a selected population without the support of specialized knives, such as the dual knife. Although the dissection speed is slower using a snare tip, it is still a recommended technique for developing country or low-income patients.

Clinical utility of the pocket-creation method with a traction device for colorectal endoscopic submucosal dissection.

BACKGROUND: Colorectal endoscopic submucosal dissection (ESD) is technically demanding while ensuring safety, especially in cases with fibrosis and/or poor maneuverability. To overcome such difficulties, we developed a novel method called the pocket-creation method with a traction device (PCM with TD). We then evaluated the effectiveness and safety of PCM with TD in colorectal ESD compared to other conventional methods. METHODS: In total, 324 colorectal lesions treated with ESD from July 2018 to June 2019 were included. The following three treatment strategies were used: conventional ESD (CE), CE with TD, and PCM with TD. Patient backgrounds and treatment outcomes were retrospectively compared and analyzed. RESULTS: As ESD methods, CE, CE with TD, and PCM with TD account for 58% (187/324), 24% (78/324), and 18% (59/324), respectively. No significant difference was observed among the three groups in en bloc and R0 resection rates or adverse events. The rate of lesions with fibrosis and poor maneuverability was significantly higher in the PCM with TD group (CE group vs CE with TD group vs PCM with TD group: fibrosis, 24% vs 47% vs 64%, p < 0.001; poor maneuverability, 5.3% vs 13% vs 20%, p = 0.002). Dissection speed was significantly higher in the PCM with TD than in the CE with TD group (p = 0.003). CONCLUSIONS: PCM with TD can achieve a stable en bloc resection rate and R0 dissection rate without adverse events even in the hands of trainees, irrespective of the size and location of the lesion, presence of fibrosis, and under poor maneuverability conditions.

Evaluation of transanal minimally invasive surgery for submucosal rectal resection in cadaveric canine specimens.

OBJECTIVE: To evaluate the feasibility of transanal minimally invasive surgery (TAMIS) for submucosal rectal resection in large breed dogs. STUDY DESIGN: Cadaveric study. SAMPLE POPULATION: Canine cadavers (n = 6) weighing between 37.5 and 60 kg. METHODS: Dogs were positioned in sternal recumbency. After rectal cleansing, a transanal access platform was placed in the rectum, and a pneumorectum was established. An area of ventral rectal wall approximately 2 × 2 cm was resected in a submucosal plane by using laparoscopic instruments and submitted for histopathological evaluation. The rectal wall defect was closed with a single-layer continuous suture pattern with barbed suture. Postoperatively, the rectum was removed en bloc and evaluated for suture or surgical penetration of the serosal surface. RESULTS: Submucosal rectal resection was successfully completed by using TAMIS in all dogs. The median length of resected specimens after fixation was 24.5 mm (range 9.8-26.5). In two of six dogs, suture was macroscopically visible on the serosal surface, but no dogs had evidence of iatrogenic full-thickness surgical penetration of the rectum. The median distance from the aborad extent of the suture closure line to the anocutaneous junction was 35 mm (range, 35-105). CONCLUSION: Submucosal resection of the canine rectal wall was feasible in large breed dogs by using TAMIS. No evidence of full-thickness penetration of the rectal wall was seen in these cadaveric specimens. CLINICAL SIGNIFICANCE: Transanal minimally invasive surgery may provide an alternative minimally invasive approach for resection for benign adenomatous rectal polyps in large breed dogs that might otherwise require a rectal pull-through.

Novel modified endoscopic mucosal resection of large GI lesions (> 20 mm) using an external additional working channel (AWC) may improve R0 resection rate: initial clinical experience.

BACKGROUND: En-bloc resection of large, flat dysplastic mucosal lesions of the luminal GI tract can be challenging. In order to improve the efficacy of resection for lesions ≥2 cm and to optimize R0 resection rates of lesions suspected of harboring high-grade dysplasia or early adenocarcinoma, a novel grasp and snare EMR technique utilizing a novel over the scope additional accessory channel, termed EMR Plus (EMR+), was developed. The aim of this pilot study is to describe the early safety and efficacy data from the first in human clinical cases. METHODS: A novel external over-the-scope additional working channel (AWC) (Ovesco, Tuebingen, Germany) was utilized for the EMR+ procedure, allowing a second endoscopic device to be used through the AWC while using otherwise standard endoscopic equipment. The EMR+ technique allows tissue retraction and a degree of triangulation during endoscopic resection. We performed EMR+ procedure in 6 patients between 02/2018-12/2018 for lesions in the upper and lower GI tract. RESULTS: The EMR+ technique utilizing the AWC was performed successfully in 6 resection procedures of the upper and/or lower GI tract in 6 patients in 2 endoscopy centers. All resections were performed successfully with the EMR+ technique, all achieving an R0 resection. No severe adverse events occurred in any of the procedures. CONCLUSIONS: The EMR+ technique, utilizing an additional working channel, had an acceptable safety and efficacy profile in this preliminary study demonstrating it's first use in humans. This technique may allow an additional option to providers to remove complex, large mucosal-based lesions in the GI tract using standard endoscopic equipment and a novel AWC device.

Rates of Incomplete Resection of 1- to 20-mm Colorectal Polyps: A Systematic Review and Meta-Analysis.

BACKGROUND & AIMS: Incomplete resection of neoplastic colorectal polyps can result in postcolonoscopy colorectal cancer. We performed a systematic review and meta-analysis to determine the incomplete resection rate (IRR) of colorectal polyps and associated factors. METHODS: We searched MEDLINE, EMBASE, EBM Reviews, and CINAHL to identify full-text articles that reported IRRs of polyps 1 to 20 mm, published until March 2019. Exclusion criteria were studies of inflammatory bowel disease cohorts, referrals for difficult polypectomy, polyp sizes larger than 20 mm, and endoscopic submucosal resection and/or dissection as polypectomy approaches. IRRs were calculated based on findings from biopsies taken at polypectomy sites or assessments of margins of resected polyps. The primary outcome was IRR for snare removal of polyps 1 to 20 mm. Secondary outcomes included IRR for polyps 1 to 10 mm and 10 to 20 mm, IRR for hot and cold snare removal of polyps 1 to 10 mm and 10 to 20 mm, IRR of snare removal with or without submucosal injection, and IRR for forceps and cold snare removal of polyps 1 to 5 mm. RESULTS: We identified 6148 reports and used 32 studies, with a total of 9282 polyps, in our quantitative analysis. The IRR for snare removal of polyps 1 to 20 mm was 13.8% (95% confidence interval [CI] 10.3-17.3; 13 studies, 5128 polypectomies). IRRs were 15.9% for snare removal of polyps 1 to 10 mm (95% CI 9.6-22.1; 9 studies, 2531 polypectomies) and 20.8% for snare removal of polyps 10 to 20 mm (95% CI 12.9-28.8; 6 studies, 412 polypectomies). The IRR for hot snare removal of polyps 1 to 10 mm was 14.2% (95% CI 5.2-23.2) vs 17.3% for cold snare polypectomy (95% CI 14.3‒20.3). The IRR for forceps removal of polyps 1 to 5 mm was 9.9% (95% CI 7.1-13.0) vs 4.4% for snare polypectomy (95% CI 2.9-6.1). CONCLUSIONS: In a systematic review and meta-analysis, we found that colorectal polyps 1 to 20 mm are frequently incompletely resected, and that risk increases for polyps 10 mm or larger. There is no difference in IRRs of cold vs hot snares for polyps 1 to 10 mm. Snare polypectomy should be used over forceps for polyps 1 to 5 mm.

Comparison among different techniques for en-bloc resection of rectal lesions: transanal endoscopic surgery vs. endoscopic submucosal dissection vs. full-thickness resection device with Over-The-Scope Clip® System.

BACKGROUND: The aim of our retrospective study is to compare the efficacy and indications of transanal endoscopic microsurgery (TEM), endoscopic submucosal dissection (ESD), and endoscopic full-thickness resection device (FTRD) with Over-The-Scope Clip (OTSC®) System for en-bloc resection of rectal lesions. METHODS: This study collected 76 cases of rectal neoplasms from a single hospital institution. Primary endpoints were complete en-bloc resection, intraprocedural adverse events, R0 en-bloc resection and an early discharge of the patient. Secondary endpoints included procedure-related adverse events. RESULTS: Mean tumor sizes were statistically significant smaller among patients treated with FTRD rather than TEM and ESD. TEO and FTRD treated patients experienced a higher en-bloc resection rate, with a shorter procedure time and hospital stay. No significant difference concerning the R0 resection was found. TEO and FTRD recorded lower perforation rates as compared to ESD, whereas no difference emerged concerning the bleeding rate and the post-polypectomy syndrome rate. CONCLUSIONS: Our study showed that each technique has specific features, so that each one offers advantages and disadvantages. Nevertheless, all of them ensure high en-bloc resection rates, whereas no difference exists for R0 resection rate. TEO provides the possibility to remove low rectal large lesions as compared to ESD and FTRD.

Robotic endoscopy. A review of the literature.

Purpose To present new endoscopic robotic devices in the context of minimally invasive procedures with high precision and automation. Methods Review of the literature by December 2018 on robotic endoscopy. Results We present the studies and investments for robotic implementation and flexible endoscopy evolution. We divided them into forceps manipulation platforms, active endoscopy and endoscopic capsule. They try to improve forceps handling and stability and to promote active movement. Conclusion The implementation and propagation of robotic models depend on doing what the endoscopist is unable to. The new devices are moving forward in this direction.