New endoscopic platform for endoluminal en bloc tissue resection in the gastrointestinal tract (with videos)

The Role of Specialized Instruments for Advanced Endoscopic Resections in Gastrointestinal Disease

INTRODUCTION

Advanced endoscopic therapy techniques have been developed and have created alternative treatment options to surgical therapy for several gastrointestinal diseases. This work will focus on new endoscopic tools for special indications of advanced endoscopic resections (ER), especially endoscopic submucosal dissection (ESD), which were developed in our institution. This paper aims to analyze these specialized instruments and identify their status.

METHODS

Initially, the technical process of ESD was analyzed, and the following limitations of the different endoscopic steps and the necessary manipulations were determined: the problem of traction-countertraction, the grasping force needed to pull on tissue, the instrument tip maneuverability, the limited angulation/triangulation, and the mobility of the scope and instruments. Five instruments developed by our team were used: the Endo-dissector, additional working channel system, external independent next-to-the-scope grasper, 3D overtube working station, and over-the-scope grasper. The instruments were used and applied according to their special functions in dry lab, experimental in vivo, and clinical conditions by the members of our team.

RESULTS

The Endo-dissector has a two-fold function: (1) grasping submucosal tissue with enough precision and strength to pull it off the surrounding mucosa and muscle, avoiding damage during energy application and (2) effectively dividing tissue using monopolar energy. The AWC system quickly fulfills the lack of a second working channel as needed to complete the endoscopic task on demand. The EINTS grasper can deliver a serious grasping force, which may be necessary for a traction-countertraction situation during endoscopic resection for lifting a larger specimen. The 3D overtube multifunctional platform provides surgical-like work with bimanual-operated instruments at the tip of the scope, which allows for a coordinated approach during lesion treatment. The OTSG is a grasping tool with very special features for cleaning cavities with debris.

CONCLUSIONS

The research and development of instruments with special features can solve unmet needs in advanced endoscopic procedures. The latter may help to increase indications for the endoscopic resections of gut lesions in the future.

Endoscopic mucosal resection and endoscopic submucosal dissection with an external additional working channel (EMR+ and ESD+) are equivalent to using a double-channel endoscope: a systematic evaluation in a porcine ex vivo model

BACKGROUND AND AIMS

With an external additional working channel (AWC) endoscopic mucosal resection (EMR) as well as endoscopic submucosal dissection (ESD) can be extended to techniques termed "EMR+" and "ESD+." These novel techniques are systematically compared to EMR and ESD under the use of a double-channel endoscope (DC).

METHODS

Our trial was conducted prospectively in a pre-clinical porcine animal model (EASIE-R simulator) with standardized gastric lesions measuring 3 or 4 cm.

RESULTS

EMR+ and EMR DC showed both good results for 3 cm lesions with no adverse events and an en bloc resection rate of 73.33% (EMR+) and 60.00% (EMR DC, p = 0.70). They came to their limits in 4 cm lesions with muscularis damages of 20.00% (EMR+), 13.33% (EMR DC, p ≥ 0.99) and decreasing en bloc resection rates of 60.00% (EMR+) and 46.67% (EMR DC, p = 0.72). ESD+ and ESD DC were both reliable concerning en bloc resection rates (100% in all groups) and adverse events (0.00% in 3 cm lesions, 12.50% muscularis damages in both ESD+ and ESD DC in 4 cm lesions). Resection time was slightly shorter in all groups with the AWC compared to DC although only reaching significance in 3 cm ESD lesions (p < 0.05*).

CONCLUSIONS

With the AWC, a standard endoscope can easily be transformed to double-channel functionality. We could show that EMR+ and ESD+ are non-inferior to EMR and ESD under the use of a double-channel endoscope. Consequently, the AWC presents an affordable alternative to a double-channel endoscope for both EMR and ESD.

Pilot study on a new endoscopic platform for colorectal endoscopic submucosal dissection

Background

The endoscopic submucosal dissection (ESD) is a technically demanding and time-consuming procedure, with an increased risk of adverse events compared to standard endoscopic resection techniques. The main difficulties are related to the instability of the operating field and to the loss of traction. We aimed to evaluate in a pilot trial a new endoscopic platform [tissue retractor system (TRS); ORISE, Boston scientific Co., Marlborough, MA, USA], designed to stabilize the intraluminal space, and to provide tissue retraction and counter traction.

Method

We prospectively enrolled all consecutive patients who underwent an ESD for sigmoid/rectal lesions. The primary outcome was the rate of technical feasibility. Further technical aspects such as en-bloc and R0 resection rate, number of graspers used, circumferential incision time, TRS assemblage time, submucosal dissection time, and submucosal dissection speed were provided. Clinical outcomes (recurrence rate and adverse events) were recorded as well.

Results

In all, 10 patients (M/F 4/6, age: 70.4 ± 11.0 years old) were enrolled. Eight out of 10 lesions were located in the rectum. Average lesion size was 31.2 ± 2.7 mm, and mean lesion area was 1628.88 ± 205.3 mm². The two sigmoid lesions were removed through standard ESD, because the platform assemblage failed after several attempts. All rectal lesions were removed in an en-bloc fashion. R0 resection was achieved in 7/8 (87.5%) patients in an average procedure time of 60.5 ± 23.3 min. None of the patients developed neither intraprocedural nor postprocedural adverse events.

Conclusion

TRS-assisted ESD is a feasible option when used in the rectum, with promising result in terms of efficacy and safety outcomes. Nevertheless, our pilot study underlines few technical limitations of the present platform that need to be overcome before the system could be widely and routinely used.

Endoscopic Management of Complex Colorectal Polyps: Current Insights and Future Trends

Most colorectal cancers arise from adenomatous polyps and sessile serrated lesions. Screening colonoscopy and therapeutic polypectomy can potentially reduce colorectal cancer burden by early detection and removal of these polyps, thus decreasing colorectal cancer incidence and mortality. Most endoscopists are skilled in detecting and removing the vast majority of polyps endoscopically during a routine colonoscopy. Polyps can be considered “complex” based on size, location, morphology, underlying scar tissue, which are not amenable to removal by conventional endoscopic polypectomy techniques. They are technically more challenging to resect and carry an increased risk of complications. Most of these polyps were used to be managed by surgical intervention in the past. Rapid advancement in endoscopic resection techniques has led to a decreasing role of surgery in managing these complex polyps. These endoscopic resection techniques do require an expert in the field and advanced equipment to perform the procedure. In this review, we discuss various advanced endoscopic techniques for the management of complex polyps.

Full-Thickness Laparoendoscopic Excision for Management of Complex Colon Polyps

BACKGROUND

Benign colon polyps are increasingly being detected because of improved colonoscopic screening and early detection of masses on the adenoma-to-carcinoma pathway. Full-thickness laparoendoscopic excision is a colon-preserving technique for endoscopically unresectable polyps consisting of endoscopically guided nonanatomic wedge colectomy.

OBJECTIVE

This study aimed to evaluate the safety and success of full-thickness laparoendoscopic excision compared to segmental colectomy for complex polyps not amenable to endoscopic resection.

DESIGN

This is a retrospective case-control study.

SETTINGS

This study was conducted at a tertiary academic center.

PATIENTS

A prospectively maintained institutional database identified 22 patients with benign complex polyps managed with full-thickness laparoendoscopic excision from 2015 to 2020. These patients were compared with 22 propensity score-matched controls from the same database that underwent laparoscopic segmental colectomy.

MAIN OUTCOME MEASURES

Primary outcome was inpatient length of stay. Secondary outcomes included operative details and postoperative morbidities.

RESULTS

Full-thickness laparoendoscopic excision was successful in all patients. Patients had a median age of 64 years (41-85), and 82% were men. Final pathology revealed complete excision of benign lesions in 20 of 22 patients and adenocarcinoma in 2 of 22. For the adenocarcinomas, 1 patient underwent subsequent elective colectomy without complications, and 1 patient declined surgery. Propensity score matching was successful for age, sex, BMI, ASA score, colon location, and prior abdominal surgery. Compared with controls, cases had significantly shorter operative time (89.5 minutes (46-290) vs 122 minutes (85-200), p = 0.009), length of stay (1 day (0-17) vs 3 days (1-8), p < 0.001), and reduced blood loss (5 mL (2-15) vs 25 mL (10-150), p < 0.001). Thirty-day morbidity (9.1% vs 27.3%, p = 0.240) was not significantly different. An unplanned 30-day reoperation was performed in 1 patient for suspected small-bowel obstruction. There was 1 mortality due to decompensated cirrhosis in the treatment group.

LIMITATIONS

This study was limited by its single-institution retrospective design.

CONCLUSIONS

Full-thickness laparoendoscopic excision is safe and successful compared with corresponding segmental colectomy for complex polyps. Favorable postoperative outcomes, including decreased operative time, length of stay, and blood loss, make it a useful approach for managing complex polyps throughout the colon.

Current Endoscopic Resection Techniques for Gastrointestinal Lesions: Endoscopic Mucosal Resection, Submucosal Dissection, and Full-Thickness Resection

Background

Endoscopic resection of dysplastic lesions in early stages of cancer reduces mortality rates and is recommended by many national guidelines throughout the world. Snare polypectomy and endoscopic mucosal resection (EMR) are established techniques of polyp removal. The advantages of these methods are their relatively short procedure times and acceptable complication rates. The latter include delayed bleeding in 0.9% and a perforation risk of 0.4-1.3%, depending on the size and location of the resected lesion. EMR is a recent modification of endoscopic resection. A limited number of studies suggest that larger lesions can be removed en bloc with low complication rates and short procedure times. Novel techniques such as endoscopic submucosal dissection (ESD) are used to enhance en bloc resection rates for larger, flat, or sessile lesions. Endoscopic full-thickness resection (EFTR) is employed for non-lifting lesions or those not easily amenable to resection. Procedures such as ESD or EFTR are emerging standards for lesions inaccessible to EMR techniques.

Summary

Endoscopic treatment is now regarded as first-line therapy for benign lesions.

Key Message

Endoscopic resection of dysplastic lesions or early stages of cancer is recommended. A plethora of different techniques can be used dependent on the lesions.

Evaluation of improved bi-manual endoscopic resection using a customizable 3D-printed manipulator system designed for use with standard endoscopes: a feasibility study using a porcine ex-vivo model

Background and study aims  A major drawback of endoscopic en-bloc resection technique is its inability to perform bimanual tasks. Although endoscopic platforms that enable bimanual tasks are commercially available, they are neither approved for various locations nor adaptable to specific patients and indications. Methods  Based on evolution of an adaptive 3D-printable platform concept, system variants with different characteristic properties were evaluated for ESD scenarios, ex-vivo in two locations in the stomach and colorectum. Results  In total 28 ESDs were performed (7 antrum, 7 corpus in inversion, 7 cecum, 7 rectum) in a porcine ex-vivo setup. ESD was feasible in 21 cases. Investigated manipulator variants are differently well suited for performing ESD within the varying interventions scenarios. Dual-arm manipulators allowed autonomous ESD, while single-arm flexible manipulators could be used more universally due to their compact design, especially for lesions difficult to access. Pediatric scopes were too frail to guide the overtube-manipulators in extremely angled positions. Working in the rectum was impaired using long-sized manipulator arms. Conclusions  The presented endoscopic platform based on 3D-printable and customizable manipulator structures might be a promising approach for future improvement of ESD procedure. With regard to localization, especially flexible manipulators attached to standard endoscopes appear to be most promising for further application of specific and individualised manipulator systems.

Colonic endoscopic submucosal dissection using a novel robotic system (with video)

BACKGROUND AND AIMS

One of the difficulties in performing endoscopic submucosal dissection (ESD) is the lack of retraction during submucosal dissection. The development of the EndoMaster EASE System (EndoMaster Pte Ltd, Singapore) aims to enhance the safety and efficacy of ESD through 2 flexible robotic arms for tissue retraction and dissection. This is a preclinical animal study to evaluate the performance of colorectal ESD using the latest version of the EndoMaster EASE System.

METHODS

The latest version of the EndoMaster EASE System consists of an independently designed, flexible platform with a built-in endoscopic imaging system and 3 working channels, 2 for the passage of robotic arms and 1 for accessories. In this animal study, the outcome measures were operating time (from starting incision to finishing dissection), completeness of resection, procedure-related adverse events, and limitations of arm manipulation in a narrow working space as assessed by counting the frequency of blind cutting.

RESULTS

Five ESD procedures were performed in a 66.7-kg porcine model with the animal under general anesthesia. The mean operative time was 73.8 minutes, and the mean size of the specimen resected was 1340 mm². There was no perforation, although profuse bleeding was encountered during 1 robotic ESD procedure.

CONCLUSIONS

The current preclinical study confirmed the feasibility of performing colorectal ESD using the latest version of the EndoMaster EASE System. The system was also tested for the ability to manage adverse events including bleeding and perforation. This study provided important preclinical experience for clinical trial.

"Unresectable" polyp management utilizing advanced endoscopic techniques results in high rate of colon preservation

PURPOSE

"Endoscopically unresectable" benign polyps identified during screening colonoscopy are often referred for segmental colectomy. Application of advanced endoscopic techniques can increase endoscopic polyp resection, sparing patients the morbidity of colectomy. This retrospective case-control study aimed to evaluate the success of colon preserving resection of "endoscopically unresectable" benign polyps using advanced endoscopic techniques including endoscopic mucosal resection, endoscopic submucosal dissection, endoluminal surgical intervention, full-thickness laparo-endoscopic excision, and combined endo-laparoscopic resection.

METHODS

A prospectively maintained institutional database identified 95 patients referred for "endoscopically unresectable" benign polyps from 2015 to 2018. Cases were compared to 190 propensity score matched controls from the same database undergoing elective laparoscopic colectomy for other reasons. Primary outcome was rate of complete endoscopic polyp removal. Secondary outcomes included length of stay, unplanned 30-day readmission and reoperation, 30-day mortality, and post-procedural complications.

RESULTS

Advanced endoscopic techniques achieved complete polyp removal without colectomy in 66 patients (70%). Failure was most commonly associated with previously attempted endoscopic resection and occult malignancy. Compared with matched colectomy controls, endoscopic polyp resection resulted in significantly shorter hospital length of stay (1.13 ± 2.41 vs 3.89 ± 4.57 days; p < 0.001), lower unplanned 30-day readmission (1.1% vs 7.7%; p < 0.05), and fewer postoperative complications (4.2% vs 33.9%; p < 0.001). Unplanned 30-day reoperation (2.1% vs 4.4%; p = 0.34) and 30-day mortality (0% vs 0.6%; p = 0.75) trended lower.

CONCLUSIONS

Endoscopic resection of complex polyps can be highly successful, and it is associated with favorable outcomes and decreased morbidity when compared with segmental colon resection. Attempting colon preservation using these techniques is warranted.

Double-clip traction could be superior to the pocket-creation method with cylindrical cap for colonic ESD: a randomized study in an ex vivo model

INTRODUCTION

In Western countries, debates between ESD vs piece-meal EMR as the best treatment for large colorectal adenomas persist regarding the difficulty of ESD the colon, and the safety and relatively good results of piece-meal endoscopic mucosal resection (EMR). Pocket-creation method (PCM) and double-clip countertraction (DCT) are two strategies recently published to facilitate ESD in this challenging situation.

METHOD

This is a randomized animal study to compare PCM and DCT strategies for colonic ESD on ex vivo models (bovine colon) performed by 3 operators novice in ESD. Hybridknife type T was used to inject normal saline tinted with a small amount of blue dye in all procedures. Randomization was stratified according to the use of gravity assist. Primary endpoint was the difference in resection speed between PCM and DCT strategies.

RESULTS

Resection speed was significantly higher in the DCT group than in the PCM group (56.3 vs. 31.6 mm²/min, p = 0.01). Technical success rate, defined as en bloc resection in under 60 min, was significantly better in the DCT group than in the PCM group (100% vs. 84.4%, p = 0.024), perforation rate was lower (0% vs. 18.8%, p = 0.012), and difficulty score was better (2.4 vs. 6.2, p < 0.0001) as was procedure duration (24.2 vs. 40.2 min, p < 0.0001).

CONCLUSION

DCT was superior to PCM for ESD in our validated bovine colon model. This strategy is inexpensive, easy to use and adaptive. It might facilitate the widespread use of colonic ESD in Western countries and change Western ideas regarding the use of colonic ESD compared with piece-meal EMR for large benign lesions.

ESD and Pit Pattern Diagnosis: Lessons from a Japanese Endoscopist Working in the United States

Endoscopic submucosal dissection (ESD) was developed in 2000s to overcome the limitations of endoscopic mucosal resection (EMR), especially to accomplish en-bloc resection, and it has been accepted worldwide in the past decades. Many ESD devices and diagnosis modalities are currently available, which include pit pattern and narrow band imaging (NBI) diagnoses to evaluate the depth of the tumor preoperatively with sensitivities of 70 to 90%. Depending on the Japanese colorectal guideline, the intramucosal cancer and shallow invasion of the submucosal layer are the main good indications of ESD; however, the ESD practices between Japan and Western countries still vary, including pathologic definition of cancer, tumor/node/metastasis classification, and handling of ESD specimen. In the United States, despite the large demand for treatment of colorectal neoplasm, pit pattern and magnified NBI diagnoses are not widely accepted yet, and piecemeal EMR is still the major method in most of the institutions. Moreover, the specific guideline of ESD is also not available yet. More new technologies are being developed other than conventional ESD methods in Eastern and Western countries, and ESD is now expected to change in the next generation. It is recommended that not only gastroenterologists but also colorectal surgeons have appropriate knowledge of colorectal lesions and their management to ensure current treatments is applied to patients.

Devices and techniques for endoscopic treatment of residual and fibrotic colorectal polyps (with videos)

BACKGROUND AND AIMS

Residual neoplasia after macroscopically complete EMR of large colon polyps has been reported in 10% to 32% of resections. Often, residual polyps at the site of prior polypectomy are fibrotic and nonlifting, making additional resection challenging.

METHODS

This document reviews devices and methods for the endoscopic treatment of fibrotic and/or residual polyps. In addition, techniques reported to reduce the incidence of residual neoplasia after endoscopic resection are discussed.

RESULTS

Descriptions of technologies and available outcomes data are summarized for argon plasma coagulation ablation, snare-tip coagulation, avulsion techniques, grasp-and-snare technique, EndoRotor endoscopic resection system, endoscopic full-thickness resection device, and salvage endoscopic submucosal dissection.

CONCLUSIONS

Several technologies and techniques discussed in this document may aid in the prevention and/or resection of fibrotic and nonlifting polyps.

Endoscopic submucosal dissection with an additional working channel (ESD+): a novel technique to improve procedure time and safety of ESD

Background and aims

A new external additional working channel (AWC) was recently introduced by which endoscopic submucosal dissection (ESD) can be converted to a technique termed “ESD+ ”. We aim to systematically evaluate this novel technique in flat gastric lesions and compare it to classical ESD.

Methods

The study was prospectively conducted in a pre-clinical ex vivo animal model (EASIE-R simulator) with porcine stomachs. Prior to intervention, we set standardized lesions measuring 3 cm or 4 cm in antegrade as well as in retrograde positions.

Results

Overall, 64 procedures were performed by an experienced endoscopist. Both techniques were reliable and showed en bloc resection rates of 100%. Overall, ESD+ reduced time of procedure compared to ESD (24.5 vs. 32.5 min, p = 0.025*). Particularly, ESD+ was significantly faster in retrograde lesions with a median of 22.5 vs. 34.0 min in 3 cm retrograde lesions (p = 0.002*) and 34.5 vs. 41.0 min (p = 0.011*) in 4 cm retrograde lesions. There were 0 perforations with both techniques. In ESD+ , 1 muscularis damage occurred (3.13%) compared to 6 muscularis damages with ESD (18.75%, p = 0.045*).

Conclusions

By its grasp-and-mobilize technique, ESD+ allows potentially faster and safer resections of flat gastric lesions compared to conventional ESD in an ex vivo porcine model. The potential advantages of ESD+ in terms of procedure time may be particularly relevant for difficult lesions in retrograde positions.

Electronic supplementary material

The online version of this article (10.1007/s00464-020-07808-w) contains supplementary material, which is available to authorized users.

Future of Endoscopy: Brief review of current and future endoscopic resection techniques for colorectal lesions

Endoscopic treatment of colorectal lesions has seen major developments in the last decade. It is now considered curative for intramucosal and superficial submucosal cancers. Endoscopic Mucosal Resection in expert hands has very good outcomes with low complication rates but recurrence and inadequate treatment of early cancers remain an issue. This has led to a technical evolution that can lead to one piece resection of neoplasia. This includes a range of techniques from knife assisted snare resection (KAR), endoscopic submucosal dissection (ESD) to full thickness resections. This article reviews all the resection techniques and the evidence base behind them.

EMR + with the AWC improves endoscopic resection speed compared to ESD: a porcine ex-vivo pilot study

INTRODUCTION

To improve resection speed and to reach higher en bloc resection rates in lesions ≥ 2 cm, a novel grasp and snare EMR technique termed "EMR+", accomplished by an additional working channel (AWC), was developed. Its use compared to endoscopic submucosal dissection (ESD) is evaluated for the first time.

MATERIAL AND METHODS

We prospectively conducted a randomized pre-clinical ex-vivo pilot study in explanted porcine stomachs for the comparison of EMR + with classical ESD of mucosal-based lesions. Prior to intervention, we set flat lesions with a standardized size of 3 × 3 cm.

RESULTS

The median time of procedure was significantly shorter in the EMR + group (median 10.5 min, range 4.4-24 min) than in the ESD group (median 32 min, range 14-61.6 min, p < .0001). The rate of en bloc resection was significantly lower in the EMR + group (38 % vs. 95 %) (p < .0001). Nevertheless, an improvement in the learning curve for EMR + was achieved after the first 12 procedures, with a subsequent en bloc resection rate of 100 %.

CONCLUSIONS

EMR + could improve the efficiency of mucosal resection procedures. Initial experience demonstrates a higher and satisfactory en bloc resection rate after going through the learning curve of EMR+.

Improved endoscopic resection of large flat lesions and early cancers using an external additional working channel (AWC): a case series

Background  En-bloc resection of large, flat lesions or early stages of cancer is challenging. No bimanual tasks are possible using standard endoscopes. Dual-channel endoscopes are not available everywhere and have a small distance between the channels. Patients and methods  A new external additional working channel (AWC) (Ovesco, Tuebingen, Germany) was designed and developed potentially enabling bimanual tasks. Fixed to the tip of a standard gastroscope or pediatric colonoscope, a second endoscopic tool can be inserted through the AWC and used for tissue retraction during endoscopic resection. Results  In the upper and lower gastrointestinal tract, endoscopic mucosal resection (EMR) with a modified grasp-and-snare technique and endoscopic submucosal dissection (ESD) were performed successfully using the AWC in eight patients. Complications were acute arterial bleeding post-EMR in two cases treated by endoscopic clipping. Conclusions  We conclude that a newly developed external additional working channel (AWC) enables endoscopic resection of large lesions in the upper and lower gastrointestinal tract. Potential benefits are its suitability for EMR and ESD, no need for a dual-channel endoscope and an adjustable distance of working channels.

Efficacy and safety of an internal magnet traction device for endoscopic submucosal dissection: ex vivo study in a porcine model (with video)

BACKGROUND

Appropriate traction allows for safer and easier endoscopic submucosal dissection (ESD). The aim of this study was to evaluate the efficacy and safety of an internal magnet traction device (MTD) for ESD in an ex vivo porcine model.

METHODS

The MTD consisted of a small neodymium magnet and a suture attached to a through-the-scope clip. A circumferential mucosal incision was completed around a 30-mm diameter template that served as the target lesion. The first MTD was deployed at the proximal edge of the lesion. A second MTD was deployed on the wall opposite the lesion. With both magnets connected, this created traction or lifting of the target lesion towards the opposing wall during submucosal dissection. Primary endpoint was comparison of submucosal dissection times between conventional ESD (C-ESD) and MTD-assisted ESD (MTD-ESD).

RESULTS

Twenty lesions along the anterior wall, posterior wall and greater curvature were resected using either C-ESD or MTD-ESD. The submucosal dissection time in MTD-ESD was significantly shorter than C-ESD (median: 6.4 [interquartile range {IQR} 4.6-8.7] min vs. 14.4 min [IQR 11.8-18.0], p < 0.05). There was a significant difference between MTD-ESD and C-ESD in total procedure times for lesions on the posterior gastric wall and greater curvature (median: 23.0 min [IQR 21.1-24.5] vs. 29.2 min [IQR 24.8-33.2], p < 0.05) with no difference for lesions on the anterior gastric wall (median: 18.8 min [IQR 15.5-20.5] vs. 17.1 min [IQR 13.1-20.0], p = 0.5). The number of muscularis propria injuries per lesion was significantly lower in MTD-ESD than C-ESD (median: 0 [IQR 0-0] vs. 1 [IQR 0-2], p < 0.05).

CONCLUSIONS

MTD for ESD is effective and safe when compared to C-ESD. This approach significantly reduced submucosal dissection times with less injury to the muscularis propria. Furthermore, MTD-ESD was particularly beneficial for more challenging gastric lesions located on the posterior wall and greater curvature.

Introduction of endoscopic submucosal dissection in the West

Endoscopic submucosal dissection (ESD) is well established in Asia as a modality for selected advanced lesions of both the upper and lower gastrointestinal tract, but ESD has not attained the same niche in the West due to a variety of reasons. These include competition from traditional surgery, minimally invasive surgery and endoscopic mucosal resection. Other obstacles to ESD introduction in the West include time commitment for learning and doing procedures, a steep learning curve, special equipment, lack of mentors, cost issues, interdisciplinary conflicts, concern regarding complications and lack of support from institutions and interfacing departments. There are intrinsic differences in pathology prevalence (e.g., early gastric cancer) between the two regions that are less conducive for ESD implementation in the West. We will elaborate on these issues and suggest measures as well as a protocol to overcome these obstacles and hopefully allow introduction of ESD as a tenable option for appropriate patients.

Recent advances in the management of large and complex colonic polyps

The endoscopic management of large colonic polyps is a rapidly changing field. Rapid evolution in endoscopic techniques and skills has resulted in diminishing the role of surgery in the management of larger and complex polyps. This is resulting in organ preservation for many who otherwise would have undergone surgery. However, it also poses new challenges. This article reviews these new advances and the developments which are overcoming these difficulties.

Robot assisted tumor resection devices

INTRODUCTION

In Japan, colorectal endoscopic submucosal dissection (ESD) is being conducted safely and effectively as shown by the increased number of the cases, however, it is still regarded as a complicated and challenging procedure. Therefore, piecemeal endoscopic mucosal resection (p-EMR) is still regarded as an appropriate treatment, rather than ESD for large colorectal tumors, especially in Western countries. Areas covered: There are several factors those are responsible for colorectal ESD difficulty. Firstly, there is no adequate traction or counter-traction in colorectal ESD. Secondly, it is challenging to handle the colonoscope in a redundant and narrow colonic lumen. Thirdly, the risk of perforation is estimated to be relatively higher compared to the stomach or esophagus Expert commentary: To overcome these difficulties, various traction and counter-traction methods have been reported and finally, the new concept of the Master and Slave Transluminal Endoscopic Robot (MASTER) has been developed and is soon to be available for clinical use. The authors have reviewed the history of colorectal ESD and MASTER in this paper.

Endoscopic mucosal resection and endoscopic submucosal dissection: technique and new directions

PURPOSE OF REVIEW

Most of small tumours in gastrointestinal tract are easily removed by endoscopic mucosal resection (EMR). However, EMR are sometimes not reliable to ensure the complete resection for large tumours. Although endoscopic submucosal dissection (ESD) was developed, it had a higher risk for complications such as perforation and bleeding. The techniques and clinical outcomes of EMR and ESD are reviewed.

RECENT FINDINGS

ESD is more effective for early gastric and oesophageal cancer with higher en-bloc resection rate and lower local recurrence in comparison to EMR. Several studies report favourable long-term outcomes of ESD. ESD has become a standard technique in Japan and other East Asian countries. Piecemeal resection using EMR technique is widely accepted for colorectal large adenomas and results in good clinical outcomes in most patients. However, apparent cancerous lesions need endoscopic en-bloc resection by ESD.

SUMMARY

Further development of the technique, devices and training systems will promote worldwide standardization of ESD.

Management of early colonic neoplasia: where are we now and where are we heading?

There have been considerable advances in the endoscopic treatment of colorectal neoplasia. The development of endoscopic submucosal dissection and full thickness resection techniques is changing the way benign disease and early cancers are managed. This article reviews the evidence behind these new techniques and discusses where this field is likely to move in the future. Areas covered: A PubMed literature review of resection techniques for colonic neoplasia was performed. The clinical and cost effectiveness of endoscopic mucosal resection (EMR) is examined. The development of endoscopic submucosal dissection (ESD) and knife assisted resection is described and issues around training reviewed. Efficacy is compared to both EMR and transanal endoscopic microsurgery. The future is considered, including full thickness resection techniques and robotic endoscopy. Expert commentary: The perceived barriers to ESD are falling, and views that such techniques are only possible in Japan are disappearing. The key barriers to uptake will be training, and the development of educational programmes should be seen as a priority. The debate between TEMS and ESD will continue, but ESD is more flexible and cheaper. This will become less significant as the number of endoscopists trained in ESD grows and some TEMS surgeons may shift across towards ESD.