Gastric endoscopic submucosal dissection assisted by a new traction method: the clip-band technique. A feasibility study in a porcine model (with video)

Is there a best choice of equipment for colorectal endoscopic submucosal dissection?

INTRODUCTION

Endoscopic submucosal dissection (ESD) is a widely used technique to remove early neoplastic lesions. It was primarily used in the initial days to treat gastric lesions, but recently, the horizon of this endoscopic procedure has expanded, which has allowed us to manage other technically more complex locations, such as the colorectum.

AREAS COVERED

There has been an exponential growth regarding the wide range of devices available in the market for performing colorectal ESD. As a result, the aim of this review is to highlight the indication of this endoscopic technique, which device is best suited for which indication, as well as future trajectories in this field.

EXPERT OPINION

Although some devices have proven to be more advantageous than others in this area, very often the choice is still subjective, which is commonly attributed to individual preferences and experience. However, an accurate knowledge of the available tools and their functioning, with their pros and cons, is fundamental for any endoscopist venturing into the field of third space endoscopy. In this way, one can choose which device best suits a particular situation, along with simultaneously having the wealth of knowledge related to therapeutic armamentarium at our disposal in the endoscopy suite.

Indications for Dental Floss Clip Traction During Gastric Endoscopic Submucosal Dissection by Less-Experienced Endoscopists

PURPOSE

Dental floss clip (DFC) traction-assisted endoscopic submucosal dissection (ESD) is widely performed owing to its simplicity. This study aimed to clarify the appropriate indications for the DFC traction method in early gastric cancer when ESD is performed by less-experienced endoscopists.

METHODS AND METHODS

We retrospectively analyzed 1,014 consecutive patients who had undergone gastric ESD performed by less-experienced endoscopists between January 2015 and December 2020. Gastric ESD was performed without DFC in all cases before December 2017 [DFC (-) group, 376 cases], and ESD was performed with DFC in all cases after January 2018 [DFC (+) group, 436 cases]. The procedure time and rates of en bloc resection, complete resection, and adverse events of the groups were compared.

RESULTS

The procedure time did not differ significantly between the 2 groups. However, when comparing lesions >20 mm, the procedure time in the DFC (+) group was significantly shorter than that in the DFC (-) group (95±46 vs. 75±31, P<0.01). The procedure time for lesions located in the greater curvature of the upper or middle stomach and lesions >20 mm located in the lesser curvature side of the stomach in the DFC (+) group was significantly shorter than that in the DFC (-) group.

CONCLUSIONS

The indications for DFC during gastric ESD by less-experienced endoscopists include lesions located in the greater curvature of the upper or middle stomach, and lesions >20 mm located in the lesser curvature of the stomach.

East versus West: Comparisons and Implications in Adaptation to Practice

Endoscopic submucosal dissection (ESD) is the preferred strategy for the resection of large superficial neoplasia throughout the gastrointestinal tract in Asian countries. The transition of ESD to the West has been slower because of various regional and training differences. Nonetheless, over the past couple of decades, the steady growth of ESD mentors in the West and the introduction of viable training pathways and dedicated devices and accessories have led to the increasing adoption of ESD and other third space endoscopic procedures.

Outcomes of Endoscopic Submucosal Dissection in Duodenal Neuroendocrine Tumors

BACKGROUND AND AIM

Endoscopic resection is recommended for small duodenal neuroendocrine tumors DNETs. However, there is limited data on the outcomes of endoscopic submucosal dissection (ESD) in DNETs. In this study, we aimed to evaluate the outcomes of ESD in DNETs.

METHODS

Data of consecutive patients who underwent ESD for DNETs from January 2018 to December 2019 were analyzed, retrospectively. All the cases of ESD were performed with or without traction using rubber band and two endoclips. En-bloc resection, complete endoscopic resection (C-ER), complete pathological resection (C-PR), adverse events, and recurrence were evaluated.

RESULTS

Twenty patients (19 males, 57.50 ± 9.32 years) underwent ESD for DNETs. DNETs measured ≤ 10 mm (7), 10-15 mm (12), and > 15 mm (1). ESD was performed with and without traction in 10 cases each. Mean operating time was 61 ± 17.38 min. En-bloc resection, C-ER, and C-PR were recorded in 90%, 95%, and 75%, respectively. Vertical margins were positive in five patients. Adverse events included perforations in 4 (20%) cases and major bleeding in one case. There was no recurrence at a mean follow-up of 17.20 ± 7.37 months.

CONCLUSION

ESD is feasible and effective for the management of DNETs. However, caution is advised due to a high risk of adverse events and pathologically incomplete resection.

Effectiveness of S-O Clip-Assisted Colorectal Endoscopic Submucosal Dissection

This study aimed to assess the utility of the S-O clip during colorectal endoscopic submucosal dissection (ESD). We conducted a retrospective study on 185 patients who underwent colorectal ESD from January 2015 to January 2020. The patients were divided into two groups: before and after the introduction of the S-O clip. Forty-two patients underwent conventional ESD (CO group) and 29 patients underwent ESD using the S-O clip (SO group). We compared the surgery duration, dissection speed, en bloc resection rate, and complication rate between both groups. Compared with the CO group, the SO group had a significantly shorter surgery duration (70.7 ± 37.9 min vs. 51.2 ± 18.6 min; p = 0.017), a significantly higher dissection speed (15.1 ± 9.0 min vs. 26.3 ± 13.8 min; p < 0.001), a significantly higher en bloc resection rate (80.9% vs. 98.8%; p ≤ 0.001), and a significantly lower perforation rate (4.3% vs. 1.3%). In the right colon, the surgery duration was significantly shorter and the dissection speed was significantly higher in the SO group than in the CO group. Moreover, the rate of en bloc resection improved significantly in the right colon. S-O clip-assisted ESD reduces the procedure time and improves the treatment effects, especially in the right colon.

Is it time for Cold-Endoscopic Submucosal Dissection? A feasibility study in an esophageal and colorectal live porcine model

Background and study aims  Use of cold endoscopic resection has increased due to excellent results with it and the ability to avoid electrosurgery related complications. The aim of this study was to evaluate the feasibility and safety of cold-endoscopic submucosal dissection (C-ESD) in an in vivo porcine model. Patients and methods  C-ESD with circumferential incision and submucosal dissection with a predominantly cold technique was tested in the esophagus and colorectum. Incision and dissection were attempted with a cold technique with a biopsy forceps and an endoscopic Maryland dissector. Large vessels were pre-coagulated with the latter device. Different traction methods were applied. Results  Twelve dissections were performed: four esophageal, four colonic, and four rectal. Tunnel and pocket methods were applied successfully. Full C-ESD was possible in the colorectum. In the esophagus, an initial incision had to be done with electrocautery. No major bleeding occurred. Two perforations occurred in the colon, one was endoscopically treated. Conclusions  Full C-ESD is feasible in the colorectum, whereas a small hot incision is needed in the esophagus. However, in 50 % of the colonic cases, there were perforations caused by the biopsy forceps making the circumferential incision. Therefore, potential benefits of endoscopic resection without cautery would warrant futures studies in humans initially in esophagus and rectal locations.

Internal traction method using a spring-and-loop with clip (S-O clip) allows countertraction in gastric endoscopic submucosal dissection

BACKGROUND

Insufficient countertraction and poor field of vision make endoscopic submucosal dissection (ESD) difficult. Internal traction method using a spring-and-loop with clip (SLC) allows sufficient traction in any direction and good field of vision. However, the attachment procedure is difficult and interference with the endoscope can occur in the retroflexed endoscopic position. We have developed a new use of SLC that simplifies the attachment procedure, eliminating interference with the endoscope. The aim of this study was to investigate the efficacy of SLC for gastric ESD.

METHODS

We retrospectively recruited 140 patients with gastric neoplasms who underwent ESD between November 2015 and October 2018 at our department. Among them, 51 patients treated using SLC-assisted ESD (SLC-ESD) and 89 patients treated using conventional ESD (C-ESD) were compared. Propensity score matching was performed to compensate for the differences in age, sex, lesion location, lesion position, specimen size, and ulcer findings. The primary outcome was ESD procedure time.

RESULTS

Propensity score matching generated 51 matched pairs. The procedure time in the SLC-ESD group was significantly shorter than that in the C-ESD group (median [interquartile], 40.0 [27.0-81.5] minutes versus 69.0 [46.5-113.5] minutes, P = 0.008). The mean SLC attachment time was 2.08 min. There were no significant differences in complete en bloc resection rate between SLC-ESD and C-ESD groups (100% versus 96.1%, P = 0.495). There were not perforation cases in either group.

CONCLUSIONS

SLC may offer an efficient method for gastric ESD, with a short attachment procedure time.

EMR/ESD: Techniques, Complications, and Evidence

PURPOSE OF REVIEW

To discuss endoscopic resection techniques of early gastrointestinal malignancy. The review will focus on the indications and outcomes of endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD).

RECENT FINDINGS

EMR is indicated for upper GI lesions less than 20 mm provided they can be easily lifted and have a low risk of submucosal invasion (SMI). ESD should be considered for esophageal and gastric lesions that are bulky, show intramucosal carcinoma, or have a risk of superficial submucosal invasion. With regard to colonic polyps, EMR is acceptable for the removal of large colonic polyps using a piecemeal technique. ESD can be reserved for rectal neuroendocrine tumors, fibrotic polyps, or polyps harboring early malignancy. In selected cases, particularly in lesions less than 2 cm in size, EMR can be safe and effective. For larger lesions or lesions with submucosal invasion, ESD is effective and curative. Choosing the best approach can be tailored for each patient depending on lesion size, pathology, and availability of local expertise.

High proficiency of colonic endoscopic submucosal dissection in Europe thanks to countertraction strategy using a double clip and rubber band

Background and study aims  ESD in the colon is more challenging technically than in other locations. Here, we report the first comparative case series of colon ESD using a systematic countertraction strategy using two clips and a rubber band. Patients and methods  Retrospective comparative study of classic versus countertraction colon ESD performed in colon ESD cases collected prospectively at Lyon Edouard Herriot Hospital and Limoges University Hospital from January 2016 until December 2017. Results  The study included 192 cases (control = 76, countertraction = 116). Countertraction using the double clip and rubber band technique versus the control group resulted in a significant decrease in the procedure time (94.7 vs . 117 min; P  = 0.004) and significant increases in procedure speed (28.2 vs . 16.7 mm ² /min; P  < 0.0001), en bloc resection rate (95.7 % vs . 76.3 %, P  < 0.0001), and R0 resection rate (78.5 % vs . 64.5 %, P  = 0.04). At an individual operator point of view, results varied between operators but the double clip countertraction strategy significantly increased the en bloc resection rate, R0 resection rate, and speed of dissection for each of the 4 operators. Conclusion  Systematic countertraction using a double clip and rubber band facilitates colon ESD. This strategy should become the standard for colon ESD.

Robot-assisted endoscopic submucosal dissection versus conventional ESD for colorectal lesions: outcomes of a randomized pilot study in endoscopists without prior ESD experience (with video)

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) is becoming the preferred method for certain early GI malignancies; however, very few U.S. physicians have adopted this technique. This is in part because of the technically challenging nature of the procedure and the long learning curve. Several endoscopic robots are under development to address these complexities.

METHODS

This is a randomized, controlled, pilot study comparing conventional ESD versus robotic-assisted ESD (RESD) in an ex vivo bovine colon model. Five endoscopists without prior ESD or RESD experience were randomized into 2 groups (group 1, RESD after ESD; group 2, RESD before ESD). A standard template was used to create colonic lesions. The primary outcome was completeness of en bloc resection. Secondary outcomes included differences in procedure time, perforation rate, muscle injury rate, and National Aeronautical and Space Administration Task Load Index (NASA-TLX) to assess physical and mental workload.

RESULTS

Five endoscopists each performed 4 tissue resections (2 RESD and 2 ESD), for a total of 20 procedures. Complete en bloc resection was achieved in all RESD and in 50% of ESD (P < .0001). The perforation rate was higher in the ESD group (60% vs 30%, P = .18). Total procedure time (34.1 vs 88.6 min, P = .001) and dissection time (27.8 vs 79.4 minutes, P = .002) were lower for RESD. The NASA-TLX also revealed better results for RESD (28.4 vs 47.4, P = .01).

CONCLUSIONS

RESD appears to be more effective in obtaining en bloc resection with shorter procedure times and a lower perforation rate compared with conventional ESD as performed by ESD novices. RESD is also associated with lower physical and mental workloads.

Snare combined with endoclips in endoscopic submucosal dissection with mucosal traction for gastroesophageal neoplasia

BACKGROUND AND AIM

Mucosal traction as a "second hand" in endoscopic submucosal dissection (ESD) is very helpful for ESD operators. The efficacy of using a snare combined with endoclips to assist in ESD (SC-ESD) was evaluated whether it could achieve peroral external traction (PET) and peroral internal traction (PIT) and real-time adjustment of mucosal traction position. This study aimed to preliminarily evaluate its feasibility.

METHODS

A snare was fixed using endoclips to the incised mucosal flap that was intended for dissection. Subsequently, the snare was adjusted to achieve mucosal traction. This study included 54 gastroesophageal neoplasias in 54 consecutive patients who underwent SC-ESD. The operative and clinical data were retrospectively collected.

RESULTS

Peroral external tractions were performed for 22 esophageal neoplasias, and PETs and PITs were performed for 32 gastric neoplasias. The median (interquartile range) sizes of lesions were 4.3 (2.5) and 4.2 (2.1) cm, operation times were 73.4 (43.8) and 60.0 (45.2) min, and submucosal dissection times were 27.0 (32.0) and 31.0 (34.5) min in the esophagus and stomach, respectively. Mucosal traction position could be effectively adjusted by fixing the snare to the incised mucosal flap intended for dissection during SC-ESD. All lesions in the esophagus and stomach were completely resected, with R0 resection rates of 100%. Besides postoperative bleeding in a patient with gastric neoplasia, no intraoperative and postoperative perforations occurred.

CONCLUSIONS

SC-ESD seems to be feasible for resecting gastroesophageal neoplasia, and two types of mucosal tractions (PET and PIT) could be effectively achieved during SC-ESD. Further prospective comparative study with a large sample is warranted.

An internal magnet traction device reduces procedure time for endoscopic submucosal dissection by expert and non-expert endoscopists: ex vivo study in a porcine colorectal model (with video)

BACKGROUND

Efficacy of an internal magnet traction device (MTD) for gastric endoscopic submucosal dissection (ESD) by an expert endoscopist has been reported. We hypothesized that use of the MTD would enhance the performance of colorectal ESD in a non-expert endoscopist in ESD compared to the conventional technique. Primary aim of this study was to compare procedure times between conventional ESD (C-ESD) and MTD-assisted ESD (MTD-ESD) by expert and non-expert endoscopists in ESD. Secondary aims included rate of en bloc resection, iatrogenic injury, visualization score of the submucosal layer, and endoscopist satisfaction score.

METHODS

A total of 56 lesions were created in an ex vivo porcine colorectum. Two endoscopists completed C-ESD (n = 28) and MTD-ESD (n = 28). Lesions measured 3 cm in diameter and were located on either the anterior or posterior colorectal wall. The MTD consisted of a small neodymium magnet and nylon monofilament attached to a through-the-scope clip. The first MTD was deployed on the opposing colorectal wall of the target lesion and a second MTD was then deployed directly onto the distal margin of the lesion.

RESULTS

Total procedure time for MTD-ESD was significantly shorter than C-ESD for both expert (median: 15.8 vs. 19.3 min, p < 0.05) and non-expert (median: 21.3 vs. 33.9 min, p < 0.001) endoscopists. All lesions were resected en bloc. There was no iatrogenic muscularis propria injury in the MTD-ESD group. For both the expert and non-expert, scores for MTD-ESD were significantly higher for submucosal layer visualization (p < 0.05) and endoscopist satisfaction (p < 0.001) compared to C-ESD.

CONCLUSIONS

Use of the MTD significantly reduced procedure time for both expert and non-expert endoscopists performing ESD. Improving the efficiency, safety, and satisfaction of ESD with such a device particularly for non-expert endoscopists is appealing and could potentially minimize the complexity and duration of the procedure allowing for more widespread use of the technique.

Endoscopic submucosal dissection in management of colorectal tumors near or involving a diverticulum: a retrospective case series

Background and study aims  Surgery is the standard treatment for colon tumors associated with diverticulum. U se of endoscopic submucosal dissection (ESD) to treat such tumors is controversial. The aim of this study was to assess the safety and feasibility of ESD in treating superficial colorectal tumors situated near or involving diverticulum. Patients and methods  Consecutive patients from two referral centers who had colorectal tumors near or involving diverticulum treated by ESD were retrospectively studied. Clinicopathological characteristics and clinical outcomes were analyzed. Results  Of the 12 patients studied, six had tumors near diverticulum and six had tumors involving diverticulum. The overall en-bloc R0 resection rate, median tumor size and procedure time were 67 %, 26.5 mm (range, 15 - 80 mm) and 110 minutes (range, 50 - 220 minutes), respectively. For tumors near diverticulum group, the en-bloc R0 resection rate was 100 % and no adverse events (AEs) or residual/recurrent tumors were observed. In contrast, for intradiverticular tumors group, the en-bloc R0 resection rate was low at 33 %, and one AE (perforation) was observed. The diverticula were ≥ 6 mm in diameter in the patients with incomplete resection. However, all but one diverticulum was unrecognized before ESD. Two residual tumors were detected at the 12-month surveillance and one required surgery. Conclusions  This case series indicates that ESD is safe and feasible for treating colorectal tumors near a diverticulum and might be feasible for tumors involving a diverticulum smaller than 6 mm. Selection for smaller diverticulum size may contribute to higher en-bloc R0 resection rates.

Suture pulley countertraction method reduces procedure time and technical demand of endoscopic submucosal dissection among novice endoscopists learning endoscopic submucosal dissection: a prospective randomized ex vivo study

BACKGROUND AND AIMS

The lack of reliable countertraction in endoscopic submucosal dissection (ESD) contributes to its technical demand and increased procedure time. We aimed to prospectively evaluate the efficacy of the suture pulley countertraction method in endoscopists new to both suturing and ESD.

METHODS

Two 30-mm circular lesions were created in an ex vivo porcine stomach model. Endoscopists considered novices for both endoscopic suturing and ESD were randomized to either traditional or suture pulley ESD first and performed ESD using each technique. Procedure time was recorded including time of circumferential incision, suture pulley placement, and submucosal dissection. After completion of each ESD, participants graded the difficulty of the procedure using the National Aeronautical and Space Administration (NASA) Task Load Index.

RESULTS

Thirteen participants (8 fellows, 5 attendings) completed the study using both methods. Mean total procedure time was shorter using suture pulley ESD compared with traditional ESD (26.7 ± 7.3 vs 59.4 ± 20.4 minutes, P < .001). The suture pulley required a mean 6.2 ± 2.1 minutes to place. Submucosal dissection time was shorter using suture pulley ESD compared with traditional ESD (8.4 ± 2.9 vs 47.2 ± 16.3 minutes, P < .001). All 7 individual indices and total score on the NASA Task Load Index were significantly improved using the suture pulley ESD method (P < .001).

CONCLUSIONS

The suture pulley countertraction method significantly decreases procedure time and technical demand of ESD among endoscopists at all skill levels who are new to ESD. The results of this study have potential implications for ESD training in the United States.

Usefulness of the clip-flap method of endoscopic submucosal dissection: A randomized controlled trial

AIM

To prospectively investigate the efficacy and safety of clip-flap assisted endoscopic submucosal dissection (ESD) for gastric tumors.

METHODS

From May 2015 to October 2016, we enrolled 104 patients with gastric cancer or adenoma scheduled for ESD at Shiga University of Medical Science Hospital. We randomized patients into two subgroups using the minimization method based on location of the tumor (upper, middle or lower third of the stomach), tumor size (< 20 mm or > 20 mm) and ulcer status: ESD using an endoclip (the clip-flap group) and ESD without an endoclip (the conventional group). Therapeutic efficacy (procedure time) and safety (complication: Gastrointestinal bleeding and perforation) were assessed.

RESULTS

En bloc resection was performed in all patients. Four patients had delayed bleeding (3.8%) and two had perforation (1.9%). No significant differences in en bloc resection rate (conventional group: 100%, clip flap group: 100%), curative endoscopic resection rate (conventional group: 90.9%, clip flap group: 89.8%, P = 0.85), procedure time (conventional group: 70.8 ± 46.2 min, clip flap group: 74.7 ± 53.3 min, P = 0.69), area of resected specimen (conventional group: 884.6 ± 792.1 mm², clip flap group: 1006.4 ± 1004.8 mm², P = 0.49), delayed bleeding rate (conventional group: 5.5%, clip flap group: 2.0%, P = 0.49), or perforation rate (conventional group: 1.8%, clip flap group: 2.0%, P = 0.93) were found between the two groups. Less-experienced endoscopists did not show any differences in procedure time between the two groups.

CONCLUSION

For patients with early-stage gastric tumors, the clip-flap method has no advantage in efficacy or safety compared with the conventional method.

Water-pocket endoscopic submucosal dissection for superficial gastric neoplasms (with video)

BACKGROUND AND AIMS

During endoscopic submucosal dissection (ESD), a clear view is essential for precise dissection of the appropriate submucosal layer. Some advantages have been reported for underwater techniques of endoscopic resection in comparison with the gas insufflation method. We have developed a new ESD method with the creation of a local water pocket (WP) that provides a clear view in the dissection field. Therefore, we aimed to investigate the feasibility and safety of WP-ESD for superficial gastric neoplasms.

METHODS

We prospectively recruited 50 patients with gastric neoplasms (early gastric cancer or gastric adenomas) between April 2017 and December 2017. Among them, 48 patients were treated with the WP-ESD technique. The patients undergoing WP-ESD were compared with 48 patients treated with standard ESD (S-ESD) who were selected by propensity score matching. The primary outcome was the ESD procedure time.

RESULTS

Total procedure time was significantly shorter in the WP-ESD group than in the S-ESD group (median [interquartile range], 27.5 [19-45] minutes vs 41 [29.8-69] minutes; P < .001). Similarly, the dissection speed was significantly greater in the WP-ESD group than in the S-ESD group (median [interquartile range], 22.5 [16.8-35.3] mm²/min vs 17.3 [12.7-22.1] mm²/min; P < .001). The rates of complete en bloc resection in the WP-ESD group and the S-ESD group were 97.9% and 95.8%, respectively (P > .99). There were no perforations in either group.

CONCLUSION

WP-ESD was associated with a shorter procedure time than S-ESD. WP-ESD may provide an alternative method for resection of superficial gastric neoplasms. (Clinical trial registration number: UMIN 000030266.).

Antigravity ESD - double-balloon-assisted underwater with traction hybrid technique

BACKGROUND AND STUDY AIMS

 Complex colorectal polyps or those positioned in difficult anatomic locations are an endoscopic therapeutic challenge. Underwater endoscopic submucosal dissection (UESD) is a potential technical solution to facilitate efficient polyp removal. In addition, endoscopic tissue retraction has been confined to limited methods of varying efficacy and complexity. The aim of this study was to evaluate the efficiency of a unique UESD technique for removing complex polyps using double-balloon-assisted retraction (R).

MATERIALS AND METHODS

 Using fresh ex-vivo porcine rectum, 4-cm polyps were created using electrosurgery and positioned at "6 o'clock" within an established ESD model. Six resections were performed in each group. Underwater techniques were facilitated using a novel double-balloon platform (Dilumen, Lumendi, Westport, Connecticut, United States).

RESULTS

 UESD-R had a significantly shorter total procedural time than cap-assisted ESD and UESD alone (24 vs. 58 vs. 56 mins). UESD-R produced a dissection time on average of 5 minutes, attributed to the retraction provided. There was also a subjective significant reduction in electrosurgical smoke with the underwater techniques contributing to improved visualization.

CONCLUSIONS

 Here we report the first ex-vivo experience of a unique double-balloon endoscopic platform optimized for UESD with tissue traction capability. UESD-R removed complex lesions in significantly shorter time than conventional means. The combined benefits of UESD and retraction appeared to be additive when tackling complex polyps and should be studied further.

Endoscopic Submucosal Tunnel Dissection for Large Gastric Neoplastic Lesions: A Case-Matched Controlled Study

Aim

To evaluate the efficacy and safety of endoscopic submucosal tunnel dissection (ESTD) for resection of large superficial gastric lesions (SGLs).

Methods

The clinicopathological records of patients performed with ESTD or endoscopic submucosal dissection (ESD) for SGLs between January 2012 and January 2014 were retrospectively reviewed. 7 cases undergoing ESTD were enrolled to form the ESTD group. The cases were individually matched at a 1 : 1 ratio to other patients performed with ESD according to lesion location, ulcer or scar findings, resected specimen area, operation time and operators, and the matched cases constituting the ESD group. The treatment outcomes were compared between the two groups.

Results

The mean specimen size was 46 mm. 10 lesions were located in the cardia and 4 lesions in the lesser curvature of the lower gastric body. En bloc resection was achieved for all lesions. The mean ESTD resection time was 69 minutes as against 87.7 minutes for the ESD (P = 0.01). The mean resection speed was faster for ESTD than for ESD (18.86 mm²/min versus 13.76 mm²/min, P = 0.03). There were no significant differences regarding the safety and curability during the endoscopic follow-up (mean 27 months).

Conclusions

ESTD is effective and safe for the removal of SGLs and appears to be an optimal option for patients with large SGLs at suitable sites.

Endoscopic submucosal tunnel dissection using a novel bracing basket: An animal feasibility study

The aim of this study was to evaluate the feasibility of a novel bracing basket for Endoscopic submucosal tunnel dissection (ESTD), which was developed for improved effectiveness and ease of use. This was a prospective randomized, comparative, experimental animal study carried out at a single center. The primary aim was to evaluate the efficacy of ESTD with a novel bracing basket, compared with conventional ESTD. The secondary aims were to assess the quality control of the procedures and adverse events. Twenty procedures (6 esophageal and 14 gastric) were performed in four pigs. All resections were completed as en bloc resections. The technical success rate was 100% for both techniques (bracing basket-assisted ESTD vs. conventional ESTD). The procedure times were similar, but the cutting speed was quicker with bracing basket-assisted ESTD in gastric (antrum:23.3 ± 2.2 mm²/min vs. 15.2 ± 3.2 mm²/min, body: 26.1 ± 1.3 mm²/min vs. 18.4 ± 2.0 mm²/min, p < 0.05). There was one bleeding in the bracing basket-assisted ESTD group and one perforation in the conventional ESTD group. Compared with conventional ESTD, the use of this basket has potential advantages. Comparison studies with larger gastric or colorectal lesions treated with conventional ESTD are needed.

Magnetic anchor guidance for endoscopic submucosal dissection and other endoscopic procedures

Endoscopic submucosal dissection (ESD) is a well-established, minimally invasive treatment for superficial neoplasms of the gastrointestinal tract. The universal adoption of ESD has been limited by its slow learning curve, long procedure times, and high risk of complications. One technical challenge is the lack of a second hand that can provide traction, as in conventional surgery. Reliable tissue retraction that exposes the submucosal plane of dissection would allow for safer and more efficient dissection. Magnetic anchor guided endoscopic submucosal dissection (MAG-ESD) has potential benefits compared to other current traction methods. MAG-ESD offers dynamic tissue retraction independent of the endoscope mimicking a surgeon’s “second hand”. Two types of magnets can be used: electromagnets and permanent magnets. In this article we review the MAG-ESD technology, published work and studies of magnets in ESD. We also review the use of magnetic anchor guidance systems in natural orifice transluminal endoscopic surgery and the idea of magnetic non-contact retraction using surface ferromagentization. We discuss the current limitations, the future potential of MAG-ESD and the developments needed for adoption of this technology.

Esophageal Endoscopic Submucosal Dissection Assisted by an Overtube with a Traction Forceps: An Animal Study

Esophageal endoscopic submucosal dissection (ESD) is technically difficult. To make it safer, we developed a novel method using overtube with a traction forceps (OTF) for countertraction during submucosal dissection. We conducted an ex vivo animal study and compared the clinical outcomes between OTF-ESD and conventional method (C-ESD). A total of 32 esophageal ESD procedures were performed by four beginner and expert endoscopists. After circumferential mucosal incision for the target lesion, structured as the isolated pig esophagus 3 cm long, either C-ESD or OTF-ESD was randomly selected for submucosal dissection. All the ESD procedures were completed as en bloc resections, while perforation only occurred in a beginner's C-ESD procedure. The dissection time for OTF-ESD was significantly shorter than that for C-ESD for both the beginner and expert endoscopists (22.8 ± 8.3 min versus 7.8 ± 4.5 min, P < 0.001, and 11.3 ± 4.4 min versus 5.9 ± 2.5 min, P = 0.01, resp.). The frequency and volume of the submucosal injections were significantly smaller for OTF-ESD than for C-ESD (1.3 ± 0.6 times versus 2.9 ± 1.5 times, P < 0.001, and 5.3 ± 2.8 mL versus 15.6 ± 7.3 mL, P < 0.001, resp.). Histologically, muscular injury was more common among the C-ESD procedures (80% versus 13%, P = 0.009). Our results indicated that the OTF-ESD technique is useful for the safe and easy completion of esophageal ESD.

Recent traction methods for endoscopic submucosal dissection

Endoscopic mucosal resection (EMR) is problematic with regard to en bloc and curable resection rates. Advancements in endoscopic techniques have enabled novel endoscopic approaches such as endoscopic submucosal dissection (ESD), which has overcome some EMR problems, and has become the standard treatment for gastrointestinal tumors. However, ESD is technically difficult. Procedure time is longer and complications such as intraoperative perforation and bleeding occur more frequently than in EMR. Recently various traction methods have been introduced to facilitate ESD procedures, such as clip with line, external forceps, clip and snare, internal traction, double scope, and magnetic anchor. Each method must be used appropriately according to the anatomical characteristics. In this review we discuss recently proposed traction methods for ESD based on the characteristics of various anatomical sites.

Endoscopic submucosal tunnel dissection for large superficial esophageal squamous cell neoplasms

Endoscopic submucosal dissection (ESD) is a well-established treatment for superficial esophageal squamous cell neoplasms (SESCNs) with no risk of lymphatic metastasis. However, for large SESCNs, especially when exceeding two-thirds of the esophageal circumference, conventional ESD is time-consuming and has an increased risk of adverse events. Based on the submucosal tunnel conception, endoscopic submucosal tunnel dissection (ESTD) was first introduced by us to remove large SESCNs, with excellent results. Studies from different centers also reported favorable results. Compared with conventional ESD, ESTD has a more rapid dissection speed and R0 resection rate. Currently in China, ESTD for large SESCNs is an important part of the digestive endoscopic tunnel technique, as is peroral endoscopic myotomy for achalasia and submucosal tunnel endoscopic resection for submucosal tumors of the muscularis propria. However, not all patients with SESCNs are candidates for ESTD, and postoperative esophageal strictures should also be taken into consideration, especially for lesions with a circumference greater than three-quarters. In this article, we describe our experience, review the literature of ESTD, and provide detailed information on indications, standard procedures, outcomes, and complications of ESTD.

Efficacy of endoscopic submucosal dissection with dental floss clip traction for gastric epithelial neoplasia: a pilot study (with video)

BACKGROUND

Providing appropriate tension to the lesion and securing a stable view of the submucosal layer is important for accomplishing successful endoscopic submucosal dissection (ESD) in gastric cancer. Dental floss clip traction (DFC), a new traction method, is proposed to reduce the difficulty of ESD. The objective of this pilot study was to investigate the efficacy of DFC for gastric ESD.

METHODS

From August to November 2014, a total of 95 patients with 104 gastric epithelial neoplasms underwent DFC-ESD (DFC group). Historical controls treated by conventional ESD (control group) were individually matched to cases at a 1:1 ratio by lesion location, ulcer findings, resected specimen size, and the proficiency of the operator (trainee/expert). The outcomes of the procedure in the two groups were then compared.

RESULTS

The mean ± SD procedure time was 43 ± 24 min in the DFC group and 52 ± 30 min in the control group (P < 0.01). Fewer lesions in the DFC group needed >80 min compared with the control group (3-vs-16 cases, P = 0.01). There were no significant differences in adverse events between the groups. Perforation and delayed bleeding occurred in one and four lesions, respectively, in the DFC group, and three and nine in the control group. En bloc resection was achieved in all cases. No significant differences were found regarding curability of ESD between the groups.

CONCLUSIONS

DFC effectively reduced ESD procedure time without increasing adverse events. DFC is helpful for rapid, safe ESD.

Colorectal endoscopic submucosal dissection: Recent technical advances for safe and successful procedures

Endoscopic submucosal dissection (ESD) is very useful in en bloc resection of large superficial colorectal tumors but is a technically difficult procedure because the colonic wall is thin and endoscopic maneuverability is poor because of colonic flexure and extensibility. A high risk of perforation has been reported in colorectal ESD. To prevent complications such as perforation and unexpected bleeding, it is crucial to ensure good visualization of the submucosal layer by creating a mucosal flap, which is an exfoliated mucosa for inserting the tip of the endoscope under it. The creation of a mucosal flap is often technically difficult; however, various types of equipment, appropriate strategy, and novel procedures including our clip-flap method, appear to facilitate mucosal flap creation, improving the safety and success rate of ESD. Favorable treatment outcomes with colorectal ESD have already been reported in many advanced institutions, and appropriate understanding of techniques and development of training systems are required for world-wide standardization of colorectal ESD. Here, we describe recent technical advances for safe and successful colorectal ESD.

East Meets West-A Novel Steerable Grasper to Facilitate Gastric Endoscopic Submucosal Dissection (ESD): Randomized Comparative Study in a Porcine Model

BACKGROUND

Endoscopic submucosal dissection (ESD) is challenging because of the limited ability of conventional endoscopic tools to achieve adequate traction. We have recently used a novel steerable grasper (SG; ANUBIS grasper, Karl Storz, Tüttlingen, Germany) with intuitive manipulating handles to lift up the mucosa. The aim of this study is to evaluate the efficacy of the assistance of the SG in a porcine acute model.

MATERIALS AND METHODS

A total of 36 gastric ESDs were performed in 12 swine (3 ESDs/pig), at the antrum, greater curvature of the gastric body, and cardia. Pigs were randomly assigned to the SG group (n = 6) or to the control group (n = 6). ESD steps included the following: scoring the area, submucosal injection, and precut and submucosal dissection with or without SG assistance. Outcomes measured were as follows: dissection time, dissection speed, size of specimen, completeness of dissection (all marks included in the specimen), en bloc dissection, and complications.

RESULTS

Overall mean dissection time was 18.6 ± 7.56 versus 29 ± 18.14 minutes (P = .032), and mean dissection speed was 94.74 ± 39.74 mm(2)/min versus 65.41 ± 39.5 mm(2)/min (P = .033) in the SG and control groups, respectively. Mean size of the specimen was 1451.4 ± 549.2 mm(2) in the SG group and 1615.3 ± 605.9 in the control group. Complete and en bloc dissections were achieved in all cases. One deep muscular injury occurred in the control group (gastric body).

CONCLUSION

The ANUBIS grasper is a user-friendly, effective, and safe tool to achieve adequate traction and exposure of the ESD plane in the pig model.

The feasibility of using simulated targets in the stomachs of live pigs for full endoscopic submucosal dissection training

Background/Aims

In endoscopic submucosal dissection (ESD) training, only a flat target lesion can usually be simulated in the normal mucosa. This study aimed to evaluate the feasibility of simulated targets in the stomachs of live pigs for complete training.

Methods

Six trained endoscopists with hands-on experience with ex vivo, isolated pig stomachs were enrolled in this pilot study. An endoscopic banding device was used to create a polyp that was snared, leaving an ulcerated lesion. This simulated target model was used to perform ESD in pigs. The en bloc resection rate, procedure time, complications, quality of resection, and participants’ opinions on the simulated targets were compared with the conventional model.

Results

En bloc resections were achieved in all six simulated targets and six conventional models. The mean size of the resected specimens was 32.2 mm (range, 20 to 39 mm) in the simulated target group and 23.5 mm (range, 11 to 40 mm) in the conventional group. The target model had a high quality of resection and had a high satisfaction rate for margin identification and correct peripheral marking.

Conclusions

Good identification of the lesion and ease of periphery marking in the target model may improve resection quality.

Facilitating endoscopic submucosal dissection: the suture-pulley method significantly improves procedure time and minimizes technical difficulty compared with conventional technique: an ex vivo study (with video)

BACKGROUND

The lack of countertraction in endoscopic submucosal dissection (ESD) results in increased technical demand and procedure time. Although the suture-pulley method for countertraction has been reported, its effectiveness compared with the traditional ESD technique remains unclear.

OBJECTIVE

To objectively analyze efficacy of countertraction using the suture-pulley method for ESD.

DESIGN

Prospective ex vivo animal study.

SETTING

Animal laboratory.

INTERVENTIONS

Twenty simulated gastric lesions were created in porcine stomachs by using a standard circular template 30 mm in diameter. In the control arm (n = 10), ESD was performed by using the standard technique. In the suture-pulley arm (N = 10), a circumferential incision was made, and an endoscopic suturing device was used to place the suture pulley.

MAIN OUTCOME MEASUREMENTS

The primary outcome of this study was total procedure time.

RESULTS

The median total procedure time with the suture-pulley method was significantly shorter than the traditional ESD technique (median, 25% to 75%, interquartile range [IQR]: 531 seconds [474.3-549.3 seconds] vs 845 seconds [656.3-1547.5 seconds], P < .001). The median time (IQR) for suture-pulley placement was 160.5 seconds (150.0-168.8 seconds). Although there was a significantly longer procedure time for proximal versus middle/lower stomach lesions with traditional ESD (median, 1601 seconds; IQR, 1547.5-1708.8 seconds vs median, 663 seconds; IQR, 627.5-681.8 seconds; P = .01), there was no significant difference in procedure time for lesions of various locations when using the suture-pulley method. Compared with traditional ESD, the suture-pulley method was less demanding in all categories evaluated by the NASA Task Load Index.

LIMITATIONS

Ex vivo study.

CONCLUSIONS

The suture-pulley method facilitates direct visualization of the submucosal layer during ESD and significantly reduces procedure time and technical difficulty. In addition, the benefit of the suture-pulley method was seen for both simple and more complicated ESDs.

A novel magnetic countertraction device for endoscopic submucosal dissection significantly reduces procedure time and minimizes technical difficulty

BACKGROUND AND STUDY AIMS

In endoscopic submucosal dissection (ESD), effective countertraction may overcome the current drawbacks of longer procedure times and increased technical demands. The objective of this study was to compare the efficacy of ESD using a novel magnetic countertraction device with that of the traditional technique.

METHODS

Each ESD was performed on simulated gastric lesions of 30 mm diameter created at five different locations. In total, 10 ESDs were performed using this novel device and 10 were performed by the standard technique.

RESULTS

The magnetic countertraction device allowed directional tissue manipulation and exposure of the submucosal space. The total procedure time was 605 ± 303.7 seconds in the countertraction group vs. 1082 ± 515.9 seconds in the control group (P = 0.021).

CONCLUSIONS

This study demonstrated that using a novel magnetic countertraction device during ESD is technically feasible and enables the operator to dynamically manipulate countertraction such that the submucosal layer is visualized directly. Use of this device significantly reduced procedure time compared with conventional ESD techniques.

Colorectal endoscopic submucosal dissection: Technical advantages compared to endoscopic mucosal resection and minimally invasive surgery

BACKGROUND AND AIM

In recent years, the effectiveness of colorectal endoscopic submucosal dissection (ESD) has been increasingly reported. Herein, we highlight the most recent developments and technical advantages of colorectal ESD compared to EMR and minimally invasive surgery.

METHODS

All candidate lesions for ESD were confirmed as being intramucosal tumors by colonoscopy. Presently, the indications for colorectal ESD approved by the Japanese government's medical insurance system are early colorectal cancers with a maximum tumor size of 2-5 cm; however, many early cancers >5 cm have been treated by ESD in referral centers.

RESULTS

The primary advantage of ESD compared to endoscopic mucosal resection (EMR) is a higher en-bloc resection rate for large colonic tumors that had previously been treated by surgery. ESD has several advantages compared to other therapeutic modalities, such as being a safer technique and providing better quality of life. For rectal cancer treatment, a longer procedure time is required for laparoscopic assisted colectomy, whereas trans-anal resection and trans-anal endoscopic microsurgery are more invasive than ESD with a significantly higher recurrence rate. Accordingly, ESD is the preferred choice for early colorectal cancers when there is no risk of lymph-node metastasis.

CONCLUSION

ESD is an effective procedure for treating non-invasive non-polypoid colorectal tumors. These tumors may be difficult to resect en bloc by conventional EMR. The use of ESD results in a higher en-bloc resection rate and is less invasive than surgery.

Gastric endoscopic submucosal dissection: From animal model to patient

AIM: To assess whether the use of porcine models is useful for learning endoscopic submucosal dissection (ESD), thus contributing to its subsequent application in human patients.

METHODS: This study/learning process was carried out in 3 phases: Phase I: Ex vivo animal; Phase II: In vivo animal; Phase III: Humans. One endoscopist performed 30 gastric ESDs in porcine models, and later 5 gastric ESDs in 5 patients. The ESD was done following the method practiced at the National Cancer Center in Tokyo, Japan. Technical aspects, size, time and speed of ESD, as well as complications were registered. In patients, their clinical, endoscopic and histologic evolution was additionally added.

RESULTS: Thirty en bloc ESDs were carried out in animal models. The mean ± SD size of the pieces was of 28.4 ± 1.2 mm, and the time of ESD was 41.7 ± 2.4 min. The time of ESD in the first 15 procedures was 43.0 ± 3.0 min whereas in the next 15 procedures, the time was 40.3 ± 3.9 min, P = 0.588. The speed in the first 15 ESDs was 1.25 ± 0.11 cm²/min vs 2.12 ± 0.36 cm²/min in the remaining 15, P = 0.028. There were no complications. In patients, 5 lesions were resected en bloc. The size of the pieces was 25.2 ± 5.1 mm and the time was 85.0 ± 25.6 min. Endoscopic and histological controls did not show evidence of residual neoplastic tissue.

CONCLUSION: A sequential ESD training program of a unique endoscopist, based on the practice in porcine models, contributed to learning ESD for its subsequent application in humans, yielding good results in efficacy and safety.

Debates on colorectal endoscopic submucosal dissection - traction for effective dissection: gravity is enough

Colorectal endoscopic submucosal dissection (ESD) still remains a technically difficult procedure. The maintenance of tissue tension and good submucosal exposure during dissection is one of the most important factors for an effective and safe dissection. Although various traction methods have been developed, traction by gravity is one of the most useful method for colorectal ESD. Traction using adjunctive devices can thus be reserved for extremely difficult cases or for endoscopists in their learning periods for colorectal ESD.

Endoscopic submucosal dissection with a novel traction method using a steerable grasper: a feasibility study in a porcine model

INTRODUCTION

Endoscopic submucosal dissection (ESD) is a technically challenging procedure in which complications and operative times depend on the operator's expertise as well as on the location and size of the lesion. Good visualization of the submucosal dissection plane is essential to perform a safe and effective ESD.

OBJECTIVES

To evaluate the feasibility, efficacy, and safety of a novel traction method using an over-the-scope steerable grasper to improve the exposure of the dissection plane during gastric ESD.

RESULTS

A total of 24 ESDs were performed without any complications in various locations of porcine stomachs, including antrum, gastric body, and cardia. En bloc complete resections were achieved in all cases. The mean specimen size was 44.92 ± 8.30 mm, mean total procedure time was 29.17 ± 11.27 minutes, and mean dissection time was 15.08 ± 7.21 minutes. The optimal dissection plane could be obtained by controlling the grasper in all cases.

CONCLUSIONS

Technical feasibility, efficacy, and safety of the over-the-scope steerable grasper technique were demonstrated in order to provide dynamic and controlled traction during ESD at different locations of porcine stomachs.

Endoluminal surgical triangulation: overcoming challenges of colonic endoscopic submucosal dissections using a novel flexible endoscopic surgical platform: feasibility study in a porcine model

BACKGROUND

Colonic endoscopic submucosal dissection (ESD) is challenging as a result of the limited ability of conventional endoscopic instruments to achieve traction and exposure. The aim of this study was to evaluate the feasibility of colonic ESD in a porcine model using a novel endoscopic surgical platform, the Anubiscope (Karl Storz, Tüttlingen, Germany), equipped with two working channels for surgical instruments with four degrees of freedom offering surgical triangulation.

METHODS

Nine ESDs were performed by a surgeon without any ESD experience in three swine, at 25, 15, and 10 cm above the anal verge with the Anubiscope. Sixteen ESDs were performed by an experienced endoscopist in five swine using conventional endoscopic instruments. Major ESD steps included the following for both groups: scoring the area, submucosal injection of glycerol, precut, and submucosal dissection. Outcomes measured were as follows: dissection time and speed, specimen size, en bloc dissection, and complications.

RESULTS

No perforations occurred in the Anubis group, while there were eight perforations (50 %) in the conventional group (p = 0.02). Complete and en bloc dissections were achieved in all cases in the Anubis group. Mean dissection time for completed cases was statistically significantly shorter in the Anubis group (32.3 ± 16.1 vs. 55.87 ± 7.66 min; p = 0.0019). Mean specimen size was higher in the conventional group (1321 ± 230 vs. 927.77 ± 229.96 mm(2); p = 0.003), but mean dissection speed was similar (35.95 ± 18.93 vs. 23.98 ± 5.02 mm(2)/min in the Anubis and conventional groups, respectively; p = 0.1).

CONCLUSIONS

Colonic ESDs were feasible in pig models with the Anubiscope. This surgical endoscopic platform is promising for endoluminal surgical procedures such as ESD, as it is user-friendly, effective, and safe.

Development and clinical usability of a new traction device "medical ring" for endoscopic submucosal dissection of early gastric cancer

Background

Although various traction devices exist for endoscopic submucosal dissection (ESD), the effects of the material used in the devices on the human body has not been considered. Moreover, there has been no report on a device that facilitates dissection both on the oral and anal side of the lesion. We made a traction device that has no deleterious effects on the body and is noninvasive, easy to use, and enables a bilateral approach in ESD. We report the process of its creation and a prospective evaluation of its usage in actual ESD procedures.

Methods

This study is prospective case control study. Thirty-seven patients for whom the device would be used were consecutively and prospectively enrolled (device used group). Control subjects in whom the device would not be used and who had lesions matched for size and location with those of the device used group were randomly selected (device not used group). Both groups were classified into three subgroups according to treatment difficulty: group A: easy; group B: intermediate; and group C: difficult. The dissection time per cm² in each group was examined.

Results

Dissection times in the device not used group/device used group were as follows: group A, 5.8/2.1 min/cm² (p < 0.01); group B, 6.1/3.8 min/cm² (p < 0.05); and group C, 7.9/3.6 min/cm² (p < 0.01), respectively.

Conclusions

The newly developed medical ring was shown to be feasible and safe and allowed excellent visualization through suitable tension and facilitated rapid gastric ESD.

Electronic supplementary material

The online version of this article (doi:10.1007/s00464-013-2887-6) contains supplementary material, which is available to authorized users.

Colorectal endoscopic submucosal dissection: is it suitable in western countries?

Endoscopic submucosal dissection (ESD) represents a significant advance in therapeutic endoscopy with the major advantage being the ability to achieve a higher en bloc resection rate for early stage lesions. Western endoscopists infrequently perform colorectal ESD (CR-ESD) because of the greater technical difficulty involved, longer procedure times, and increased risk of perforation. Specialized training and sufficient clinical experience are necessary to successfully perform ESDs, but a systematic education and training program has still not been established in Japan or elsewhere in the world. Experts generally acknowledge that the stomach is the first organ in which endoscopists should begin performing ESDs. The incidence and detection rates for early stage gastric cancer are significantly higher in Japan than in western countries, so Japanese endoscopists have a greater opportunity to perform gastric ESDs than their western counterparts. It is logical to ask, therefore, whether CR-ESD can be effectively applied in western countries. Based on a review of the relevant literature and our practical perspective, we have focused on the progress made in performing CR-ESD, its indications, training methods, and learning curve. Use of animal gastric and colon models is strongly recommended along with accumulating the necessary experience from the rectum to the colon on a step-by-step basis. It is reasonable to assume that an increasing number of CR-ESDs will be performed by western endoscopists in the foreseeable future given the continuing development of new techniques, and the refinement of instruments and other technologically advanced devices together with the creation of even more effective submucosal injection agents.

Ex vivo and in vivo models for endoscopic submucosal dissection training

Endoscopic submucosal dissection is a technically challenging but highly effective technique for the treatment of well selected early neoplasms in the digestive tract. Although it is frequently performed in East Asian countries, the Western world has not adopted this technique yet, probably due in part to the difficulty to learn it. Ex vivo and in vivo animal models are invaluable tools to overcome at least the beginning of the learning curve, although the initial step is the acquisition of basic knowledge about early diagnosis of neoplasias, and observing real procedures in expert centers. The practical issues, advantages, and disadvantages of the ex vivo and in vivo models are discussed.

Endoscopic submucosal dissection--current success and future directions

More than 10 years have passed since endoscopic submucosal dissection (ESD) was first developed in Japan. ESD enables en bloc complete resection of superficial gastrointestinal neoplasms regardless of the size and location of the lesions. With improvements in techniques and devices, excellent therapeutic results have been achieved despite the inherent technical difficulties of this procedure. ESD aiming for curative treatment can be performed for gastrointestinal neoplasms without risk of lymph node metastasis. Accurate histopathologic examination of the resected specimen is required to determine the risk of lymph node metastasis, for which en bloc resection is beneficial. Owing to the high success rate of en bloc complete resection and accurate histopathologic examination, tumour recurrence rates after ESD are reported to be very low in Japan. Excellent results of ESD in a large number of cases have also been reported from other Asian countries such as South Korea, Taiwan and China. Although scepticism exists among Western clinicians regarding the application of ESD, it is developing slowly and reports indicate promising results in some European countries. With further development of technologies, such as endoscopic robotics, ESD could become the worldwide treatment of choice for early gastrointestinal neoplasms.

Supportive techniques and devices for endoscopic submucosal dissection of gastric cancer

The indications for endoscopic treatment have expanded in recent years, and relatively intestinal-type mucosal stomach carcinomas with a low potential for metastasis are now often resected en bloc by endoscopic submucosal dissection (ESD), even if they measure over 20 mm in size. However, ESD requires complex maneuvers, which entails a long operation time, and is often accompanied by complications such as bleeding and perforation. Many technical developments have been implemented to overcome these complications. The scope, cutting device, hemostasis device, and other supportive devices have been improved. However, even with these innovations, ESD remains a potentially complex procedure. One of the major difficulties is poor visualization of the submucosal layer resulting from the poor countertraction afforded during submucosal dissection. Recently, countertraction devices have been developed. In this paper, we introduce countertraction techniques and devices mainly for gastric cancer.

Colorectal endoscopic submucosal dissection in Japan and Western countries

Various studies by Japanese endoscopists have demonstrated that colorectal endoscopic submucosal dissection (ESD) can overcome technical limitations of the endoscopic mucosal resection (EMR) technique such as piecemeal resection for flat lesions larger than 20 mm, resection of lesions involving the dentate line or the ileocecal valve and lesions with the non-lifting sign, and achieve higher en bloc resection rate. However, it is infrequently performed in Western countries in comparison with Japan, despite the advantages explained above. There are some differences between Japan and Western countries in environments and clinical settings for performing ESD in the colorectum. Endoscopists who perform colorectal ESD around the world are considering that refinements in ESD techniques, devices and training will be necessary to further reduce a higher risk of complications and longer procedure times before adoption of ESD can be recommended on a widespread international scale.

[Endoscopic submucosal dissection: only for expert endoscopists?]

Endoscopic submucosal dissection (ESD) can be applied to early gastrointestinal cancers. This technique was developed to achieve radical curative resection and to reduce unnecessary surgical interventions. ESD was designed in eastern countries and is not widely used in the West. Although ESD represents a major therapeutic advance in endoscopy and is performed with curative intent, the complication rate (hemorrhage, perforation) is higher than reported in other techniques, requiring from endoscopists the acquirement of technical skill and experience through a structured and progressive training program to reduce the morbidity associated with this technique and increase its potential benefits. Although there is substantial published evidence on the applications and results of ESD, there are few publications on training in this technique and a standardized training program is lacking. The current article aims to describe the various proposals for training, as well as the basic principles of the technique, its indications, and the results obtained, since theoretical knowledge that would guide endoscopists during the clinical application of ESD is advisable before training begins. Training in an endoscopic technique has a little value without knowledge of the technique's aims, the situations in which it should be applied, and the results that can be expected.