Endoscopic submucosal dissection for large colorectal tumors using a cross-counter technique and a novel large-diameter balloon overtube

ESD with elastic ring traction is more effective and safer than conventional ESD in large proximal colon neoplastic lesions: a retrospective cohort study (with video)

BACKGROUND AND AIMS

Colorectal endoscopic submucosal resection (ESD), especially ESD in proximal colon, has always been challenging. We invented a novel elastic ring as a traction method to facilitate ESD. Our study aims to compare the safety and effectiveness of ESD with in vivo traction and conventional ESD without traction in the treatment of large proximal colon neoplastic lesions.

METHODS

This retrospective cohort study included consecutive patients with large (≥ 20 mm in their maximal diameter) proximal colon neoplastic lesions who underwent ESD with in vivo elastic ring traction or conventional ESD without traction in our endoscopy center between June 2018 and April 2022 by one experienced endoscopist.

RESULTS

The ESD with traction group has lower overall complication rate and lower perforation rate than those in the conventional ESD group (0% vs 14.71%, P = 0.021; 0% vs 11.76%, P = 0.048, respectively), and the differences are statistically significant. Although there are no significant differences in the rates of en bloc resection and R0 resection and bleeding rate, ESD with traction group still had higher en bloc resection and R0 resection rates and lower bleeding rate than conventional ESD group without traction (100% vs 94.12%, P = 0.226; 94.59% vs 85.29%, P = 0.189, 8.82% vs 2.70%, P = 0.276, respectively).

CONCLUSION

ESD with elastic ring traction is potentially more effective and safer than conventional ESD in the treatment of large proximal colon neoplastic lesions. Further large, prospective controlled studies are needed to fully evaluate this novel method.

Application of in vivo traction-assisted resection of proximal colon lesions: a case series (with video)

BACKGROUND

Endoscopic submucosal dissection (ESD) is the treatment of choice for colorectal neoplasms in Japan. ESD can completely peel off the lesion and is associated with a significantly lower recurrence rate of colorectal cancers than EMR and is widely used to treat gastrointestinal tumors. This study aimed to evaluate in vivo traction in endoscopic submucosal dissection (ESD) of proximal colon lesions.

METHODS

This retrospective study included patients with lesions in the proximal colon who received ESD treatment at Qilu Hospital of Shandong University from June 2018 to December 2020. Patients were divided into two groups according to the in vivo traction method (orthodontic ring or elastic ring) during operation. The operation time, dissection time, proportion of complete resection of lesions, and complications were compared between the two groups.

RESULTS

There were 28 patients in this study. In the orthodontic ring group (n = 10), the average lesion diameter was 2.0-2.5 cm, and the average operation and dissection times were 26.5 ± 7.47 and 21.5 ± 7.47 min, respectively. In the elastic ring group (n = 18), the average lesion diameter was 2.5-5.5 cm, and the average operation and dissection times were 27.39 ± 11.83 and 22.39 ± 11.83 min, respectively. All lesions were completely resected in a single operation, and no wound perforation and delayed bleeding occurred.

CONCLUSION

In vivo traction-assisted ESD can be used to resect proximal colon lesions in selected patients (precancerous lesions and early colon cancer limited to the mucosa or with a submucosa infiltration depth of < 1000 µm).

Effectiveness of a multi-loop traction device for colorectal endoscopic submucosal dissection performed by trainees: a pilot study

Colorectal endoscopic submucosal dissection (ESD) is a difficult procedure, and its introduction to trainees has been debated. Although the criteria for performing colorectal ESD vary among institutions, it is often allowed after gaining experience performing surgeries in animals and upper gastrointestinal ESD. This pilot study aimed to compare the treatment outcomes of ESD performed by trainees using the multi-loop traction device (MLTD group) and those of conventional ESD performed by experts (control group). It also aimed to determine whether the MLTD can be used to safely introduce colorectal ESD to trainees. We included 26 colorectal ESD patients (13 in the MLTD group and 13 in the control group) treated at our hospital from October to December 2021. There were no significant differences in the procedure time (50 min vs. 30 min), dissection speed (19.9 mm²/min vs. 28.7 mm²/min), and intraoperative perforation (0% vs. 0%) of the two groups. Furthermore, the rate of ESD self-completion in the MLTD group was 100%. Therefore, the use of the MLTD allowed the safe introduction of colorectal ESD, even among endoscopists with no experience performing colorectal ESD. Consequently, the use of the MLTD may replace animal and upper gastrointestinal ESD when introducing colorectal ESD to trainees.

The usefulness of a double-balloon endolumenal interventional platform for colorectal endoscopic submucosal dissection by non-expert endoscopists in a porcine model (with video)

BACKGROUND

Endoscopic submucosal dissection (ESD) is an optimal treatment for colorectal tumors; however, it is technically difficult, especially for non-experts. Therefore, a device that helps non-experts perform colorectal ESD would be beneficial. A double-balloon endolumenal interventional platform (DEIP) was recently developed to assist colorectal ESD through endoscope stabilization and traction. This study assessed the usefulness of colorectal ESD using the DEIP (DEIP-ESD) by endoscopists, including non-experts, in a living porcine model.

METHODS

Two pigs were used to perform eight DEIP-ESD and eight conventional cap-assisted ESD (C-ESD) procedures. Three experts and five non-experts each resected one lesion using DEIP-ESD and one using C-ESD. We evaluated the treatment outcomes and performed stratified analyses between the experts and non-experts.

RESULTS

Dissection speed was significantly faster in DEIP-ESD than in C-ESD (13.3 mm²/min vs 28.5 mm²/min, P = 0.002). However, the total procedure time did not differ significantly between DEIP-ESD and C-ESD. In the stratified analyses, the dissection speed of non-experts was significantly faster in DEIP-ESD than in C-ESD (10.9 mm²/min vs 25.1 mm²/min, P = 0.016), while that of experts increased in DEIP-ESD but to a lesser extent (19.1 mm²/min vs 28.8 mm²/min, P = 0.1). The total procedure time did not differ between DEIP-ESD and C-ESD for both experts and non-experts. The self-completion rate of non-experts also increased in DEIP-ESD. Moreover, the number of muscularis propria injuries induced by non-experts was fewer in DEIP-ESD than in C-ESD.

CONCLUSIONS

DEIP could facilitate colorectal ESD by improving dissection efficiency without increasing adverse events, especially when performed by non-experts.

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.

Comparison of the Effectiveness and Safety of Different Methods of Colorectal Endoscopic Submucosal Dissection: A Systematic Review and Network Meta-Analysis

BACKGROUND

Traditional endoscopic submucosal dissection (ESD) has developed different methods, such as pocket method (P-ESD), traction-assisted method (T-ESD), and hybrid method (H-ESD). In this meta-analysis, the benefits and drawbacks of different ESD methods were discussed and ranked.

STUDY DESIGN

Studies comparing different methods of colorectal ESD were searched by using PubMed, EMBASE, and Cochrane Library databases. The study was conducted for five endpoints: en bloc resection rate, R0 resection rate, operation time, dissection speed, and adverse events rate. Pairwise and network meta-analyses were performed through Rev Man 5.4 and Stata 16.0. The quality of all included studies was assessed using the Cochrane Risk of Bias Tool and the Newcastle-Ottawa Scale.

RESULTS

Twenty-six studies met the inclusion criteria, including 7 RCTs and 19 non-RCTs, with a total of 3,002 patients. The pooled analysis showed that the en bloc resection rate of H-ESD was significantly lower than that of C-ESD, P-ESD, and T-ESD (RR = 0.28, 95% CI [0.12, 0.65]; RR = 0.11, 95% CI [0.03, 0.44]; RR = 8.28, 95% CI [2.50, 27.42]). Compared with C-ESD, the operation time of H-ESD and T-ESD was significantly shorter (MD = -21.83, 95% CI [-34.76, -8.90]; MD = -23.8, 95% CI [-32.55, -15.06]). Meanwhile, the operation time of T-ESD was also significantly shorter than that of P-ESD (MD = -18.74, 95% CI [-31.93, -5.54]). The dissection speed of T-ESD was significantly faster than that of C-ESD (MD = 6.26, 95% CI [2.29, 10.23]).

CONCLUSION

P-ESD and T-ESD are probably the two best methods of colorectal ESD at present. The advantages of P-ESD are high en bloc resection rate and low incidence of adverse events. The advantages of T-ESD are rapid dissection and short operation time.

Efficacy of Current Traction Techniques for Endoscopic Submucosal Dissection

This systematic review aimed to assess the efficacy of the current approach to tissue traction during the endoscopic submucosal dissection (ESD) of superficial esophageal cancer, early gastric cancer, and colorectal neoplasms. We performed a systematic electronic literature search of articles published in PubMed and selected comparative studies to investigate the treatment outcomes of tractionassisted versus conventional ESD. Using the keywords, we retrieved 381 articles, including five eligible articles on the esophagus, 13 on the stomach, and 12 on the colorectum. A total of seven randomized controlled trials and 23 retrospective studies were identified. Clip line traction and submucosal tunneling were effective in reducing the procedural time during esophageal ESD. The efficacy of traction methods in gastric ESD varied in terms of the devices and strategies used depending on the lesion location and degree of submucosal fibrosis. Several prospective and retrospective studies utilized traction devices without the need to reinsert the colonoscope. When pocket creation is included, the traction devices and methods effectively shorten the procedural time during colorectal ESD. Although the efficacy is dependent on the organ and tumor locations, several traction techniques have been demonstrated to be efficacious in facilitating ESD by maintaining satisfactory traction during dissection.

Colorectal Endoscopic Submucosal Dissection: An Update on Best Practice

Endoscopic submucosal dissection (ESD) is a method of en-bloc resection of neoplastic colorectal lesions which is less invasive compared to surgical resection. Lesion stratification, architecture recognition and estimation of depth of invasion are crucial for patient selection. Expert endoscopists have integrated a variety of classification systems including Paris, lateral spreading tumor (LST), narrow band imaging (NBI), international colorectal endoscopic (NICE) and Japanese NBI expert team (JNET) in their day-to-day practice to enhance lesion detection accuracy. Major societies recommend ESD for LST-non granular (NG), Kudo-VI type, large depressed and protruded colonic lesions with shallow submucosal invasion. Chance of submucosal invasion enhances with increased depth as well as tumor location and size. In comparison to endoscopic mucosal resection (EMR), ESD has a lowerl recurrence rate and higher curative resection rate, making it superior for larger colonic lesions management. Major complications such as bleeding and perforation could be seen in up to 11% and 16% of patients, respectively. In major Western countries, performing ESD is challenging due to limited number of expert providers, lack of insurance coverage, and unique patient characteristics such as higher BMI and higher percentage of previously manipulated lesions.

Traction-assisted endoscopic submucosal dissection reduces procedure time and risk of serious adverse events: a systematic review and meta-analysis

BACKGROUND AND AIMS

Conventional endoscopic submucosal dissection (C-ESD) is a technically demanding procedure with prolonged procedure times and higher risk of adverse events. To overcome the procedural difficulty of ESD, several traction-assisted techniques (T-ESD) have been developed to improve visualization of the submucosa in hopes to facilitate safe and effective dissection. The aim of this study was to conduct a meta-analysis that compares short-term outcomes (30-day) of T-ESD to C-ESD.

METHODS

Clinical studies published up to April 2020 comparing the efficacy and safety of T-ESD and C-ESD were identified using electronic bibliographic searches. Both randomized controlled trials and observational studies were included. Outcomes of interests were procedure time, rates of en bloc and R0 resection, and rates of adverse events. Fixed effect and random effect model were used to calculate pooled mean difference for continuous variables and risk differences (RDs) for categorical variables.

RESULTS

Twenty-three studies with 2574 patients were included in this meta-analysis, with a total of 2582 lesions (1292 T-ESD and 1290 C-ESD). Pooled estimates of T-ESD showed shorter procedure times (weighted mean difference = -20.35 min, 95% CI -27.51 to -13.19, p < 0.001), higher R0 resection rates (RD 0.04, 95% CI 0.01-0.06, p = 0.004) and lower perforation rates (RD -0.03, 95% CI -0.04 to -0.01, p =  < 0.0001). No significant differences were seen in en bloc rates and bleeding risk between the two groups.

CONCLUSIONS

Traction-assisted ESD results in shorter procedure time, improved R0 resection rates and lower risk of perforation as compared to conventional ESD.

Review on colorectal endoscopic submucosal dissection focusing on the technical aspect

BACKGROUND

Endoscopic submucosal dissection (ESD) enables removal of broad-based colorectal polyps or lateral spreading tumors with a higher rate of en bloc resection and a lower risk of local recurrence. However, it is technically demanding. Over the past 20 years, various equipment and innovative techniques have been developed to reduce the difficulty of ESD. The information in the literature is scattered. Our aim is to provide a comprehensive review on the setup and technical aspects of colorectal ESD.

METHODS

We searched the PubMed database and systemically reviewed all original and review articles related to colorectal ESD. Further manual search according to reference lists of identified articles were done. The selected articles were categorized and reviewed. Original figures were created to help readers understand some of the ESD techniques.

RESULTS

A total of 216 articles were identified, in which 25 of them were review articles and 191 of them were original articles. They were categorized and reviewed. An in-depth appraisal of the setting, equipment, and technical aspects of colorectal ESD was performed.

CONCLUSIONS

Although ESD is a technically demanding procedure that requires expert endoscopic skills, it can be mastered. With good peri-procedural preparation, sufficient knowledge of the equipment, and thorough understanding of the useful endoscopic tricks and maneuvers, colorectal ESD can be performed smoothly and safely.

Methods that Assist Traction during Endoscopic Submucosal Dissection of Superficial Gastrointestinal Cancers: A Systematic Literature Review

Endoscopic submucosal dissection (ESD) is a well-established method for the treatment of early-stage gastrointestinal neoplasms. Adequate submucosal exposure is one of the most significant factors related to an effective and safe dissection. The aim of this systematic review was to evaluate the effcacy and safety of various methods that assist traction during ESD of precancerous and earlystage neoplastic lesions of the gastrointestinal tract. We performed an electronic search of the MEDLINE and the Cochrane Controlled Trials Register databases for relevant studies published up to May 2019. Trials exclusively recruiting patients undergoing ESD for superficial gastrointestinal cancer were considered eligible for inclusion. Thirty-three articles including 3,134 patients met the inclusion criteria. The studies evaluated different approaches for widening the endoscopic view, including magnetic anchor-guided ESD (3 studies), use of a second endoscope (5 studies), clip-involving technique (21 studies), and miscellaneous methods (4 studies). Among them, only 6 were randomized controlled trials evaluating different approaches. Overall, the implementation of methods that assist traction during ESD significantly improved the operating time and R0 resection rate and decreased the rate of complications (bleeding and perforation). Interventions that assist traction seem effcacious in improving tissue traction, thus facilitating ESD performance.

Short-term outcomes of traction-assisted versus conventional endoscopic submucosal dissection for superficial gastrointestinal neoplasms: a systematic review and meta-analysis of randomized controlled studies

Background

In recent years, some traction-assisted approaches have been introduced to facilitate endoscopic submucosal dissection (ESD) procedures by reducing the procedure time and risks related to the procedure. However, the relative advantages of traction-assisted endoscopic submucosal dissection (T-ESD) are still being debated. This study aimed to assess the efficacy of T-ESD for the treatment of superficial gastrointestinal neoplasms.

Methods

We searched MEDLINE, Embase, and Cochrane library up to March 31, 2019 for randomized controlled trials (RCTs) comparing T-ESD and conventional endoscopic submucosal dissection (C-ESD) for superficial gastrointestinal neoplasms. The main endpoints are en bloc resection, complete resection, procedure time, perforation, and delayed bleeding. Pooled risk ratio (RR), Peto odds ratio (OR), and mean difference (MD) were calculated to compare T-ESD and C-ESD. This study is registered with PROSPERO, number CRD42018108135.

Results

A total of 7 RCTs with 1007 patients were included in this meta-analysis. There were no significant differences between the T-ESD and C-ESD groups in the pooled estimate of en bloc resection, complete resection, and delayed bleeding (RR = 1.00, 95% CI 0.99, 1.01, I² = 0%, P = 0.66; RR = 1.00, 95% CI 0.98, 1.03, I² = 0%, P = 0.81; OR = 0.95, 95% CI 0.48, 1.86, I² = 19%, P = 0.87,respectively). The pooled estimate indicated that the procedure time was significantly shorter in the T-ESD group (MD = − 16.19, 95% CI − 29.24, − 3.13, I² = 87%, P = 0.02) than in the C-ESD group. Compared to C-ESD, T-ESD was associated with lower incidence of perforation (OR = 0.32, 95% CI 0.11, 0.91, I² = 0%, P = 0.03).

Conclusions

T-ESD is a safe and effective treatment option with a low perforation rate and shorter procedure time than C-ESD for superficial gastrointestinal neoplasms. Future multi-center (including European populations), randomized controlled trials of larger sample size and long-term outcomes of T-ESD are required.

Management of colorectal laterally spreading tumors: a systematic review and meta-analysis

Objective and study aims  To evaluate the efficacy and safety of different endoscopic resection techniques for laterally spreading colorectal tumors (LST). Methods  Relevant studies were identified in three electronic databases (PubMed, ISI and Cochrane Central Register). We considered all clinical studies in which colorectal LST were treated with endoscopic resection (endoscopic mucosal resection [EMR] and/or endoscopic submucosal dissection [ESD]) and/or transanal minimally invasive surgery (TEMS). Rates of en-bloc/piecemeal resection, complete endoscopic resection, R0 resection, curative resection, adverse events (AEs) or recurrence, were extracted. Study quality was assessed with the Newcastle-Ottawa Scale and a meta-analysis was performed using a random-effects model. Results  Forty-nine studies were included. Complete resection was similar between techniques (EMR 99.5 % [95 % CI 98.6 %-100 %] vs. ESD 97.9 % [95 % CI 96.1 - 99.2 %]), being curative in 1685/1895 (13 studies, pooled curative resection 90 %, 95 % CI 86.6 - 92.9 %, I ²  = 79 %) with non-significantly higher curative resection rates with ESD (93.6 %, 95 % CI 91.3 - 95.5 %, vs. 84 % 95 % CI 78.1 - 89.3 % with EMR). ESD was also associated with a significantly higher perforation risk (pooled incidence 5.9 %, 95 % CI 4.3 - 7.9 %, vs. EMR 1.2 %, 95 % CI 0.5 - 2.3 %) while bleeding was significantly more frequent with EMR (9.6 %, 95 % CI 6.5 - 13.2 %; vs. ESD 2.8 %, 95 % CI 1.9 - 4.0 %). Procedure-related mortality was 0.1 %. Recurrence occurred in 5.5 %, more often with EMR (12.6 %, 95 % CI 9.1 - 16.6 % vs. ESD 1.1 %, 95 % CI 0.3 - 2.5 %), with most amenable to successful endoscopic treatment (87.7 %, 95 % CI 81.1 - 93.1 %). Surgery was limited to 2.7 % of the lesions, 0.5 % due to AEs. No data of TEMS were available for LST. Conclusions  EMR and ESD are both effective and safe and are associated with a very low risk of procedure related mortality.

Efficacy of traction-assisted colorectal endoscopic submucosal dissection using a clip-and-thread technique: A prospective randomized study

BACKGROUND AND AIM

Colorectal endoscopic submucosal dissection (ESD) remains challenging because of technical difficulties, long procedure time, and high risk of adverse events. To facilitate colorectal ESD, we developed traction-assisted colorectal ESD using a clip and thread (TAC-ESD) and conducted a randomized controlled trial to evaluate its efficacy.

METHODS

Patients with superficial colorectal neoplasms (SCN) ≥20 mm were enrolled and randomly assigned to the conventional-ESD group or to the TAC-ESD group. SCN ≤50 mm were treated by two intermediates, and SCN >50 mm were treated by two experts. Primary endpoint was procedure time. Secondary endpoints were TAC-ESD success rate (sustained application of the clip and thread until the end of the procedure), self-completion rate by the intermediates, and adverse events.

RESULTS

Altogether, 42 SCN were analyzed in each ESD group (conventional and TAC). Procedure time (median [range]) for the TAC-ESD group was significantly shorter than that for the conventional-ESD group (40 [11-86] min vs 70 [30-180] min, respectively; P < 0.0001). Success rate of TAC-ESD was 95% (40/42). The intermediates' self-completion rate was significantly higher for the TAC-ESD group than for the conventional-ESD group (100% [39/39] vs 90% [36/40], respectively; P = 0.04). Adverse events included one intraoperative perforation in the conventional-ESD group and one delayed perforation in the TAC-ESD group.

CONCLUSION

Traction-assisted colorectal endoscopic submucosal dissection reduced the procedure time and increased the self-completion rate by the intermediates (UMIN000018612).

Recent Development of Techniques and Devices in Colorectal Endoscopic Submucosal Dissection

Colorectal endoscopic submucosal dissection (ESD) is now a well-established endoscopic treatment for early-stage colorectal neoplasms, especially in Asian countries, including Japan. Despite the spread of colorectal ESD, there are still situations in which achieving successful submucosal dissection is difficult. Various novel techniques and devices have been developed to overcome these difficulties, and past reports have shown that some of these strategies can be applied to colorectal ESD. We review several recent developments in the field. The techniques reviewed include the pocket creation method and traction methods and the devices reviewed include the overtube with balloon and electrosurgical knives with water-jet function. These improved techniques and devices can facilitate safer, more reliable ESDs and expand its applicability and acceptability all over the world.

Efficacy of hybrid endoscopic submucosal dissection (ESD) as a rescue treatment in difficult colorectal ESD cases

BACKGROUND AND AIM

Endoscopic submucosal dissection (ESD), which provides a higher en bloc resection rate than conventional endoscopic mucosal resection (EMR), is considered to be a useful treatment option for large colorectal tumors. However, colorectal ESD is not widely used because of its technical difficulty, risk of complications and time required. To overcome these drawbacks, a simpler modified technique, ESD with snaring (hybrid ESD), has been developed. The aim of the present study was to retrospectively compare the safety and efficacy of hybrid ESD and conventional ESD for colorectal tumors.

METHODS

Between September 2008 and June 2016, ESD was carried out on 137 lesions and hybrid ESD on 27 lesions. All hybrid ESD cases were carried out as a rescue treatment in difficult ESD cases. We retrospectively investigated procedure time, and the rates of en bloc resection, perforation, bleeding, and local recurrence.

RESULTS

In the hybrid ESD group, procedure time was shorter compared with the ESD group (108 ± 59.5 min vs 122 ± 72.2 min), but the en bloc resection rate was lower (66.7% vs 94.2%). However, there were no significant differences in procedure time, or in rates of en bloc resection, perforation and bleeding between the two groups. Local recurrence did not develop in any of our cases.

CONCLUSIONS

Hybrid ESD as a rescue treatment in difficult ESD cases may be less effective for en bloc resection of large colorectal tumors. Indication for hybrid ESD may be limited to scheduled treatment from the outset and emergency cases with patients who present unstable vital signs during ESD.

Traction-assisted colonic endoscopic submucosal dissection using clip and line: a feasibility study

BACKGROUND AND STUDY AIMS

Colonic endoscopic submucosal dissection (ESD) is a challenging procedure because it is often difficult to maintain good visualization of the submucosal layer. To facilitate colonic ESD, we designed a novel traction method, namely traction-assisted colonic ESD using clip and line (TAC), and investigated its feasibility.

PATIENTS AND METHODS

We retrospectively analyzed 23 patients with large colonic superficial lesions who had undergone TAC. The main outcome was the procedural success rate of TAC, which we defined as successful, sustained application of clip and line to the lesion until the end of the procedure.

RESULTS

The procedural success rate of TAC was 87 % (20/23). In all three unsuccessful cases, the lesions were in the proximal colon and the procedure times over 100 minutes. The overall mean procedure time was 61 min (95 % confidence interval, 18 - 172 min). We achieved en bloc resections of all lesions. There were no perforations or fatal adverse events.

CONCLUSIONS

TAC is feasible and safe for colonic ESD and may improve the ease of performing this procedure.

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.

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.

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.

Lessons from imperfect endoscopic submucosal dissection of rectal tumor

Endoscopic mucosal resection (EMR) is a standard endoscopic treatment for gastrointestinal tumors, but resections done in a piecemeal fashion are difficult to diagnose pathologically as curative resections, and the local recurrence rate is relatively high. Recently, endoscopic submucosal dissection (ESD) for colorectal tumors, which provides a higher complete resection rate than conventional EMR, has rapidly come into widespread use in Japan. However, colorectal ESD is still technically difficult and has complications such as perforation, and the procedure time is longer than that of conventional EMR. We report herein a case in which a rectal tumor was resected with an inappropriate specimen due to imperfect ESD. This lesion had severe fibrosis in the submucosal layer because the lesion had been injected with a solution for EMR in another hospital, which resulted in non-lifting signs, and had been subjected to many biopsies. During the ESD in our hospital, the submucosal layer was not clearly identified, and a small injury was caused in the specimen. A precise diagnosis based on histopathological findings could not be made because of the inappropriate specimen. Thus, expertise in both the diagnostic and the therapeutic aspects is required before treating large colorectal tumors.

Warning for unprincipled colorectal endoscopic submucosal dissection: accurate diagnosis and reasonable treatment strategy

Piecemeal endoscopic mucosal resection (EMR) is generally indicated for laterally spreading tumors (LST) >2 cm in diameter. However, the segmentation of adenomatous parts does not affect the histopathological diagnosis and completeness of cure. Thus, possible indications for piecemeal EMR are both adenomatous homogenous-type granular-type LST (LST-G) and LST-G as carcinoma in adenoma without segmentalizing the carcinomatous part. Diagnosis of the pit pattern using magnifying endoscopy is essential for determining the correct treatment and setting segmentation borders. In contrast, endoscopic submucosal dissection (ESD) is indicated for lesions requiring endoscopic en bloc excision, as it is difficult to use the snare technique for en bloc excisions such as in non-granular-type LST (LST-NG), especially for the pseudodepressed type, tumors with a type VI pit pattern, shallow invasive submucosal carcinoma, largedepressed tumors and large elevated lesions, which are often malignant (e.g. nodular mixed-type LST-G). Other lesions, such as intramucosal tumor accompanied by submucosal fibrosis, induced by biopsy or peristalsis of the lesion; sporadic localized tumors that occur due to chronic inflammation, including ulcerative colitis; and local residual early carcinoma after endoscopic treatment, are also indications for ESD. In clinical practice, an efficient endoscopic treatment with segregation of ESD from piecemeal EMR should be carried out after a comprehensive evaluation of the completeness of cure, safety, clinical simplicity, and cost-benefit, based on an accurate preoperative diagnosis.

Counter traction makes endoscopic submucosal dissection easier

Poor counter traction and poor field of vision make endoscopic submucosal dissection (ESD) difficult. Good counter traction allows dissections to be performed more quickly and safely. Position change, which utilizes gravity, is the simplest method to create a clear field of vision. It is useful especially for esophageal and colon ESD. The second easiest method is clip with line method. Counter traction made by clip with line accomplishes the creation of a clear field of vision and suitable counter traction thereby making ESD more efficient and safe. The author published this method in 2002. The name ESD was not established in those days; the name cutting endoscopic mucosal resection (EMR) or EMR with hook knife was used. The other traction methods such as external grasping forceps, internal traction, double channel scope, and double scopes method are introduced in this paper. A good strategy for creating counter traction makes ESD easier.