A novel method of endoscopic mucosal resection using sodium hyaluronate

Endoscopic Mucosal Resection and Endoscopic Submucosal Dissection

Up to 15% of colorectal polyps are amenable for conventional polypectomy. Advanced endoscopic resection techniques are introduced for the treatment of those polyps. They provide higher en bloc resection rates compared with conventional techniques, while helping patients to avoid the complications of surgery. Note that 20 mm is considered as the largest size of a polyp that can be resected by polypectomy or endoscopic mucosal resection (EMR) in an en bloc fashion. Endoscopic submucosal dissection (ESD) is recommended for polyps larger than 20 mm. Intramucosal carcinomas and carcinomas with limited submucosal invasion can also be resected with ESD. EMR is snare resection of a polyp following submucosal injection and elevation. ESD involves several steps such as marking, submucosal injection, incision, and dissection. Bleeding and perforation are the most common complications following advanced endoscopic procedures, which can be treated with coagulation and endoscopic clipping. En bloc resection rates range from 44.5 to 63% for EMR and from 87.9 to 96% for ESD. Recurrence rates following EMR and ESD are 7.4 to 17% and 0.9 to 2%, respectively. ESD is considered enough for the treatment of invasive carcinomas in the presence of submucosal invasion less than 1000 μm, absence of lymphovascular invasion, well-moderate histological differentiation, low-grade tumor budding, and negative resection margins.

Effectiveness and safety of newly introduced endoscopic submucosal dissection in a Western center: a real-life study

OBJECTIVES

Endoscopic submucosal dissection (ESD) is a minimally invasive technique for the resection of superficial gastrointestinal lesions, providing high rates of 'en bloc' and R0 resection. East-West differences in ESD quality indicators have been reported. This study aims to assess feasibility, effectiveness, and safety of ESD for the treatment of superficial gastrointestinal (GI) lesions in a Western cohort.

METHODS

Consecutive patients undergoing ESD at one Italian endoscopic referral center from September 2018 to March 2020 were included in this prospective study. Primary outcomes were technical success, R0 resection rate, curative resection rate, and adverse events (AEs).

RESULTS

In total 111 patients (111 lesions) undergoing ESD were included. Anatomic site of the lesions was rectum in 56.8%, colon in 13.5%, stomach in 24.3%, and esophagus in 5.4% of cases, respectively. For upper GI procedures, technical success was 100%, and R0 and curative resection rates were 84.8% and 78.8%, respectively. For colorectal procedures, technical success was 98.7%, R0 and curative resection rates were 88.5% and 84.6%, respectively. Major AEs were reported in 12 cases (10.8%).

CONCLUSION

The introduction of ESD in a Tertiary Center is feasible, effective, and safe, and should be taken into consideration for the treatment of superficial GI lesions requiring 'en bloc' resection.

Endoscopic submucosal dissection of endobronchial leiomyoma with a hybrid knife in an adolescent patient: a case report

Endobronchial leiomyomas are uncommon benign tracheobronchial tumors. Bronchoscopic intervention is a safe and effective strategy for patients with contraindications for surgery or refusal to undergo surgery. Endoscopic submucosal dissection (ESD) is widely used to treat early gastrointestinal tumors. The novel hybrid knife is useful during ESD owing to functions of submucosal injections, lesion dissection and hemostasis, and makes ESD more convenient. Here, we report a case of a benign leiomyoma at the orifice of RB7 in an adolescent boy. The diagnosis was confirmed based on bronchoscopic and pathological findings. The patient was successfully treated with combined electrocautery snare and cryoresection, ESD using a hybrid knife and the wound was managed with argon plasma coagulation. The postoperative course was satisfactory, with a good general condition and no severe respiratory symptoms. This is, to our knowledge, the first reported case of ESD using a hybrid knife to treat an endobronchial leiomyoma in an adolescent patient.

Colorectal endoscopic submucosal dissection in the West: A systematic review and meta-analysis

Background and study aims The advantages of endoscopic submucosal dissection (ESD) over endoscopic mucosal resection for large colorectal neoplasms are well established; however, the technical challenges and lack of adequate training in ESD limit its widespread adoption in Western countries. Methods A literature search was performed in Medline, Embase, Web of Science, and the Cochrane Library for studies conducted in non-Asian countries evaluating the effectiveness of colorectal ESD. A random effects model was used to obtain pooled en bloc, R0 resection rates, and adverse events (AEs). Results Thirty-three studies comprising 3,958 ESD procedures met the inclusion criteria. Of the polyps, 96.7% (2,817 of 2913) were ≥ 2 cm. Pooled en bloc resection (31 studies), R0 resection (29 studies), and curative resection rates were 84.6% (95% confidence interval [CI] [83.3%-85.9%]), 75.6% (95% CI [74.1%-77.0%]), and 81.9% (95% CI [78.6%-84.9%]), respectively. Surgery for invasive cancer was performed in 4.8% (23 studies). ESD-related perforation (25 studies) was observed in 5.5% and bleeding in 4.1% (delayed bleeding 3.4%). 1.8% of patients underwent surgery for procedure-related complications. A high degree of heterogeneity was observed for en bloc resection, R0 resection, and curative resection. Heterogeneity for AEs (perforation [I 2 13%], delayed bleeding [I 2 30%], and overall bleeding [I 2 49%]) was low to moderate. Conclusions The effectiveness of colorectal ESD for large colorectal polyps and early colorectal cancers is improving in Western countries, and recent resection rates are comparable to that seen in Asia. Colorectal perforation is still observed in about 5% of ESD; however, < 2% of patients need emergency surgery for AEs.

Bulking agents in gastrointestinal endoscopy: present applications and future advances

PURPOSE OF REVIEW

Bulking agents are inert materials injected into an organ to affect the physical properties of the organ for a therapeutic purpose. Various agents have been developed to aid in the treatment of diseases like gastroesophageal reflux disease (GERD), fecal incontinence, obesity, malignancy, hemostasis, and tissue dissection. Here, we review the state of the art in bulking agents in gastrointestinal endoscopy, past failures, current limitations, and where we see the field heading in the future.

RECENT FINDINGS

Though bulking agents have been trialed for various different gastrointestinal diseases, there are currently limited uses in gastrointestinal endoscopy. Though various agents have been trialed for GERD, numerous complications and adverse events have limited its current use. However, for the treatment of fecal incontinence endoscopic bulking agent therapy is a reasonable option. Though in early stages of exploration, bulking agent therapy for enteric protection from radiotherapy may be a promising tool to improve treatment of pancreatic cancer. Bulking agents for tissue dissection have substantially improved lifting agents and complex polyp removal. Bulking agent therapy has not really been explored for endoscopic bariatric therapy or hemostasis but may be a fruitful area for exploration in the future.

SUMMARY

Bulking agent therapy has been trialed for various gastrointestinal diseases with mixed success. There is currently a therapeutic roll in the endoscopic management of fecal incontinence and tissue dissection. A future role in the treatment of GERD, obesity, malignancy, and hemostasis seem feasible.

Knives in Third Space

Endoscopic mucosal resection (EMR) has always been done with a snare. The maximum diameter of the snare is usually 2 cm and the largest lesion that can be removed in one piece is usually maximum of 2 cm. In EMR, after the elevation of the submucosa, snares are used for the resection of the mucosal lesion; however, for endoscopic submucosal dissection (ESD), special knives are required, which have various uses in different areas of the gastrointestinal tract. ESD knives have developed and evolved over the past 30 years allowing it to be performed safely. It allows very precise cutting of the mucosa as well as dissection of the submucosal tissue planes. This review discusses some of the more commonly used knives.

Efficacy and safety of endoscopic resection techniques of large colorectal lesions: experience of a referral center in Italy

BACKGROUND

Endoscopic mucosal resection and submucosal dissection (ESD) are treatments of choice for superficial neoplastic colorectal lesions. Only a few studies have compared these techniques.

AIM

To compare the efficacy and safety of endoscopic piecemeal mucosal resection (EPMR), ESD and hybrid-endoscopic submucosal dissection (H-ESD) of large colorectal lesions in a Western endoscopic center.

METHODS

This is a retrospective analysis on a prospective medical database of consecutive colorectal superficial lesions larger than 20 mm, resected by EPMR, ESD or H-ESD collected from 2015 to 2019.

RESULTS

Two hundred twenty-nine colorectal lesions were included. All lesions were completely endoscopically resected, 65.9% by EPMR, 19.7% by ESD and 14.4% by H-ESD. Endoscopic control after the index procedure was available for 86.5% patients. Among these patients, 80% had a second follow-up colonoscopy. The overall recurrence rate was 13.2, 0 and 6.1% for EPMR, ESD and H-ESD respectively, with a significant difference between EPMR and ESD. All recurrences were endoscopically treated during follow-up procedures. Risk of complications was not significantly different between the three groups.

CONCLUSIONS

EPMR, ESD and H-ESD are effective and safe procedures. Recurrence rate in EPMR was higher but can be managed endoscopically with high success rates. EPMR is faster and technically simpler so should be considered a potential first-line therapy for colorectal superficial neoplastic lesions.

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

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

Endoscopic Submucosal Dissection in Europe: Results of 1000 Neoplastic Lesions From the German Endoscopic Submucosal Dissection Registry

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) enables the curative resection of early malignant lesions and is associated with reduced recurrence risk. Due to the lack of comprehensive ESD data in the West, the German ESD registry was set up to evaluate relevant outcomes of ESD.

METHODS

The German ESD registry is a prospective uncontrolled multicenter study. During a 35-month period, 20 centers included 1000 ESDs of neoplastic lesions. The results were evaluated in terms of en bloc, R0, curative resection rates, and recurrence rate after a 3-month and 12-month follow-up. Additionally, participating centers were grouped into low-volume (≤20 ESDs/y), middle-volume (20-50/y), and high-volume centers (>50/y). A multivariate analysis investigating risk factors for noncurative resection was performed.

RESULTS

Overall, en bloc, R0, and curative resection rates of 92.4% (95% confidence interval [CI], 0.90-0.94), 78.8% (95% CI, 0.76-0.81), and 72.3% (95% CI, 0.69-0.75) were achieved, respectively. The overall complication rate was 8.3% (95% CI, 0.067-0.102), whereas the recurrence rate after 12 months was 2.1%. High-volume centers had significantly higher en bloc, R0, curative resection rates, and recurrence rates and lower complication rates than middle- or low-volume centers. The lesion size, hybrid ESD, age, stage T1b carcinoma, and treatment outside high-volume centers were identified as risk factors for noncurative ESD.

CONCLUSION

In Germany, ESD achieves excellent en bloc resection rates but only modest curative resection rates. ESD requires a high level of expertise, and results vary significantly depending on the center's yearly case volume.

Endoscopic submucosal dissection vs endoscopic mucosal resection for colorectal polyps: A meta-analysis and meta-regression with single arm analysis

BACKGROUND

Endoscopic submucosal dissection (ESD) has shown to be effective in management of colorectal neoplasm in the Asian countries, while its implementation in Western countries where endoscopic mucosal resection (EMR) is preferred is still debatable.

AIM

To compare the surgical, histological, and oncological outcomes between ESD and EMR in the treatment of colorectal polyps, with subgroup analysis comparing the efficacy of ESD and EMR between Japan and the rest of the world.

METHODS

Embase and Medline databases were searched from inception to October 2020 in accordance with PRISMA guidelines for studies comparing en bloc, complete resection, margin involvement, resection time, need for additional surgery, complications, and recurrence rate of ESD with EMR.

RESULTS

Of 281344 colorectal polyps from 21 studies were included. When compared to EMR, the pooled analysis revealed ESD was associated with higher en bloc and complete resection rate, and lower lateral margin involvement and recurrence. ESD led to increased procedural time, need for additional surgery, and perforation risk. No significant difference in bleeding risk was found between the two groups. Meta-regression analysis suggested only right colonic polyps correlated with an increased perforation risk in ESD. Confounders including polyp size and invasion depth did not significantly influence the en bloc and complete resection rate, bleeding risk and recurrence. In subgroup analysis, Japan performed better than the rest of the world in both ESD and EMR with perforation risk of 4% and 0.0002%, respectively, as compared to perforation risk of 8% and 1%, respectively, in reports coming from rest of the world.

CONCLUSION

ESD resulted in better resection outcomes and lower recurrence compared to EMR. With appropriate training, ESD is preferred over EMR as the first-line therapy for resection of colorectal polyps, without restricting to lesions greater than 20 mm and those with high suspicion of submucosal invasion.

Injectable Thermosensitive Chitosan Solution with β-Glycerophosphate as an Optimal Submucosal Fluid Cushion for Endoscopic Submucosal Dissection

Endoscopic submucosal dissection (ESD) is a surgical procedure to remove early neoplastic lesions in the gastrointestinal tract with the critical issue of perforation. A submucosal fluid cushion, such as normal saline, is used as a cushioning agent to prevent perforation; however, its cushioning maintenance is insufficient for surgery. In this study, we introduce an injectable thermosensitive chitosan solution (CS) with β-glycerophosphate (β-GP) as a submucosal injection agent for ESD. The CS/β-GP system with optimal β-GP concentration showed drastic viscosity change near body temperature while other commercial products did not. Additionally, the injectability of the solution was similar to or greater than other commercial products. The solution with low β-GP concentration showed low cytotoxicity similar to other products. An in vivo preclinical study illustrated maintenance of the high cushioning of the thermosensitive solutions. These results indicate that a CS/β-GP system with optimal β-GP concentration might be used as a submucosal injection agent in ESD, and further studies are needed to validate the effectiveness of the solutions in vivo.

A Comparative Study on Aqueous Chitosan Solution and Various Submucosal Injection Fluids Using a Three-Dimensional Sensor

Background/Aims

Chitosan, a natural polymer widely used in the biomaterials field, has been proposed as a potential submucosal injection solution. The purpose of this study was to compare the performance and efficacy of aqueous chitosan solution and commercialized submucosal injection fluids using a three-dimensional sensor and to evaluate the efficacy of the measured parameters.

Methods

Normal saline (0.9% NaCl), as a control, Eleview^® (Poloxamer 188), Blue Eye^TM (0.4% hyaluronic acid), and aqueous chitosan solution (2.0%) were injected into the submucosa of porcine stomachs ex vivo. The mucosal elevation height, elevated surface area, and angle of the tangent of the submucosal fluid cushion were measured using a three-dimensional sensor. The rates of change for each variable were calculated, and the correlation between parameters was analyzed. Tissue specimens were stained with hematoxylin and eosin.

Results

All variables exhibited the highest values under chitosan injection. The mucosal elevation height rate of change differed significantly between normal saline and chitosan solution (p=0.024). The elevated surface area rates of change for normal saline and Eleview^® were significantly different from those for TS-905 and chitosan solution (p=0.006 and p=0.009, respectively). Further, height, area, and angle showed a positive correlation (p<0.001). A histological examination revealed an even distribution of aqueous chitosan within the submucosa without tissue damage.

Conclusions

Aqueous chitosan was superior to normal saline and Eleview^® and was noninferior to TS-905. A three-dimensional sensor and the measured parameters were effective and useful for evaluating the performance of submucosal fluids.

Differences between two sodium hyaluronate-based submucosal injection materials currently used in Japan based on viscosity analysis

In Japan, two 0.4% sodium hyaluronate (HA)-based submucosal injection materials (SIMs) are currently used in endoscopic submucosal dissection (ESD): MucoUp (HA-Mc) and Ksmart (HA-Ks). HA-Mc and HA-Ks have the same concentration and are, thus, construed by most endoscopists to have no difference. Nevertheless, visual observation conveys the impression that HA-Ks have a higher viscosity than HA-Mc, suggesting that HA-Ks performs better than HA-Mc. This study aimed to examine the differences between HA-Mc and HA-Ks. HA-Ks exhibited higher viscosity due to greater weight-average molecular weight compared with HA-Mc. HA-Ks had significantly greater submucosal elevation height (SEH) than HA-Mc; the SEH of HA-Ks-80% (80% dilution of HA-Ks) was the same as that of HA-Mc. The ESD procedure time was significantly shorter with HA-Ks than with HA-Mc (15.2 ± 4.1 vs. 19.5 ± 5.9; P = 0.049). The total injection volume for HA-Ks was significantly lower than that for HA-Mc (10.8 ± 3.6 vs. 14.4 ± 4.6; P = 0.045). However, no significant difference in these items was observed between HA-Mc and HA-Ks-80%. HA-Mc and HA-Ks were considered to be almost the same. Nonetheless, HA-Ks exhibited higher viscosity and SIM performance than HA-Mc. HA-Ks-80% had almost the same performance as HA-Mc. Thus, understanding SIM performance and characteristics requires a focus on the viscosity of SIMs.

An innovative next-generation endoscopic submucosal injection material with a 2-step injection system (with video)

BACKGROUND AND AIMS

Next-generation submucosal injection materials (SIMs) with higher performance and flexibility than the current SIMs (eg, 0.4% sodium hyaluronate solution [HA]) are expected to improve the outcomes of endoscopic submucosal dissection (ESD) but are difficult to develop. We developed a next-generation SIM by devising a 2-solution-type SIM comprising 2.0% calcium chloride solution (Ca) and 0.4% sodium alginate solution (SA) and evaluated its performance.

METHODS

Viscoelasticity, submucosal elevation height, and injection pressure of HA, SA, and the next-generation SIM were measured. Outcomes of ESDs on pseudo-lesions in ex vivo porcine stomach/colon models were compared.

RESULTS

The dramatic increase in SA viscoelasticity with the addition of Ca facilitated the formation of highly viscous submucosal cushions that can be controlled by endoscopists. The submucosal elevation height of the next-generation SIM was significantly higher than that of HA or SA with the same injection pressure. The ESD procedure time using the next-generation SIM was significantly shorter than that using HA or SA (14.2 ± 6.1 vs 29.2 ± 9.1 minutes, P = .0004, or 14.2 ± 6.1 vs 29.1 ± 5.9 minutes, P <.0001). Furthermore, the total injection volume for the next-generation SIM was considerably lower than that for HA or SA (7.0 ± 0.9 vs 17.2 ± 3.4 mL, P <.0001, or 7.0 ± 0.9 vs 16.2 ± 2.9 mL, P <.0001).

CONCLUSIONS

We developed an ideal next-generation SIM that achieved high performance and high flexibility in ex vivo models. Our findings warrant further investigations in a patient population.

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.

Evaluation of Eleview® Bioadhesive Properties and Cushion-Forming Ability

Submucosal injection is generally required for both endoscopic-mucosal resection (EMR) and submucosal dissection (ESD). SIC-8000 (Eleview®) is a new liquid composition in the form of a microemulsion for submucosal injection, approved by the Food and Drug Administration (FDA) 510(k) and Conformité Européene (CE) marked, containing a biocompatible polymer as a cushioning agent. The aim of this study was to evaluate Eleview®’s performance in terms of bioadhesive properties and cushion-forming ability. The bioadhesion was evaluated by measuring the interaction between Eleview® and the extracellular matrix (the main component of the submucosal layer) using the texture analyzer. To better comprehend the mechanism of action of Eleview® after submucosal injection, force of detachment and adhesion work were measured for the following formulations: Eleview®, Eleview® without poloxamer (functional polymer), poloxamer solution alone, normal saline, and MucoUp® (competing product on the Japanese market). The results obtained show the interaction between Eleview® and the extracellular matrix, highlighting the stronger bioadhesive properties of Eleview® compared with Eleview® without poloxamer, poloxamer solution alone, as well as normal saline and MucoUp®. The ability of Eleview® to form a consistent and long-lasting cushion in situ, once injected into the submucosal layer, was tested ex vivo on a porcine stomach. The results obtained show a better permanence in situ for the product compared with normal saline injection and to MucoUp® (t-test, p < 0.05).

Endoscopic submucosal dissection: an update on tools and accessories

Endoscopic submucosal dissection (ESD) is a minimally invasive therapeutic procedure to remove larger polyps or early non-metastatic lesions. It has long been used in Asia, but is now fast growing in popularity in the West. There are multiple challenges faced by ESD practitioners. While the practice of ESD in gastric lesions is relatively well established, the oesophagus with its narrow lumen and challenging workspace, and the colon with its tortuous course and folds are more challenging frontiers. The nature of performing a procedure endoscopically means that conventional methods offer no mechanism for providing counter-traction while performing dissection, impeding visibility and increasing the rate of complications. There are a multitude of tools available to those performing ESD for the different stages of the procedure. This article reviews the accessories currently used in regular ESD practice including the knives used to cut and dissect lesions, the cap and hood devices used to improve visibility and safety, injection fluids to lift the submucosal plane, haemostatic devices, generators, and finally, emerging traction apparatus. There is some evidence behind the use of these tools, however, ESD remains the domain of a small number of practitioners and the practice relies heavily on expert experience. Evolution of the ESD toolbox will make the procedure more accessible to more endoscopists, which in turn will drive the development of a more substantial evidence base to evaluate efficacy and safety of the multitude of tools.

EndoClot®SIS Polysaccharide Injection as a Submucosal Fluid Cushion for Endoscopic Mucosal Therapies: Results of Ex Vivo and In Vivo Studies

BACKGROUND

There are many studies on submucosal injection materials, but their clinical use is restricted for various reasons. The objective of this study was to compare the feasibility and safety of injected EndoClot^®SIS polysaccharide as a submucosal injection material (SFC) in ESD in the pig stomach to that of injected sigMAVisc™ or Eleview™.

METHODS

Four pig stomachs were used for the ex vivo study. Eighteen pigs were used for the in vivo study. In the ex vivo study, four injections were made in the gastric submucosa to induce submucosal uplift and extend its duration. Tissue change was observed. The in vivo study was performed in 2 steps. First, 3 injections were made in the esophageal mucosa to induce submucosal uplift and extend its duration. Histological change was observed. Second, ESD was performed in the stomach by injecting EndoClot^®SIS polysaccharide, sigMAVisc™, or Eleview™ (each, n = 6) as an SFC. The effects of these agents on wound healing were examined. We evaluated the efficacy and safety of endoscopic surgery after EndoClot^®SIS polysaccharide injection.

RESULTS

EndoClot^®SIS polysaccharide produced a longer-lasting elevation with clearer margins than was achieved by sigMAVisc™, Eleview™, or 0.9% NaCl and thereby enabled precise ESD without complications, such as bleeding and perforation. No obvious histopathological damage was observed at the injection site on endoscopy and histology.

CONCLUSION

Submucosally injected EndoClot^®SIS polysaccharide increased the effective separation of the mucosa and submucosa and reduced surgical complications. Hence, EndoClot^®SIS polysaccharide injection is a safe and effective submucosal injection material.

Efficacy and safety of endoscopic submucosal dissection for non-ampullary duodenal polyps: A systematic review and meta-analysis

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) is commonly used to treat early-stage digestive cancer because it results in a higher frequency of en-bloc resection and a lower frequency of local recurrence. However, the efficacy and safety of duodenal ESD remain unclear. Therefore, present study is aimed at evaluating clinical outcomes of duodenal ESD.

METHODS

To evaluate the efficacy and safety of duodenal ESD, electronic databases (MEDLINE, CENTRAL and EMBASE) were searched by two independent reviewers. The authors were contacted for additional information. A meta-analysis was performed to evaluate the efficacy and safety of duodenal ESD.

RESULTS

A total of 7 studies (203 patients) were included in the quantitative synthesis analysis. The pooled proportions of the frequencies of en-bloc resection, need for surgical intervention, bleeding, intraoperative perforation and delayed perforation were 87%, 4%, 2%, 15% and 2%, respectively. The quality of evidence regarding on surgical intervention outcomes was rated as moderate, whereas that of en-bloc resection was rated as low because of its marked inconsistency.

CONCLUSIONS

Duodenal ESD produced acceptable outcomes in terms of the en-bloc R0 resection, but the incidence of procedure-related adverse events is high (PROSPERO register, CRD42017057110).

Endoscopic submucosal dissection with a novel high viscosity injection solution (LiftUp) in an ex vivo model: a prospective randomized study

Introduction  Endoscopic submucosal dissection (ESD) is increasingly being used in the western world. Submucosal injectates are an essential tool for the ESD procedure. In this study, we evaluated a novel copolymer injectate (LiftUp, Ovesco, Tübingen Germany) in an established ESD model (EASIE-R) in comparison to existing submucosal injectables. Materials and methods  We conducted a prospective, randomized ex vivo study performing ESD with three injectates: LiftUp, hydroxyethyl starch (HAES 6 %) and normal saline solution (NaCl 0.9 %). A total of 60 artificial lesions, each 3 × 3 cm in size, were resected in an ex vivo porcine model, utilizing one of the three studied injectates (n = 20 ESDs per injectate). Study parameters were: en bloc resection rate, perforation rate, lifting property, time of injection, injectate volume, general ESD procedure time, and overall procedure time. Results  All 60 lesions were successfully resected using the standard ESD technique. LiftUp had no procedure related perforations, one perforation occurred in the HAES group, and two perforations in the NaCl group ( P  > 0.05). Furthermore, adequate lifting was achieved in 16/20 (80 %) using LiftUp, 6/20 (30 %) in the HAES group and 6/20 (30 %) in the NaCl group ( P  < 0.0002). En bloc resection was achieved in 19 (95 %) with LiftUp, in 20 (100 %) with HAES, and in 16 (80 %) with NaCl. General ESD procedure time and overall procedure time were not different among the three groups. Conclusion  LiftUp appears to be a safe alternative to established fluids for ESD. It had a significantly improved lifting effect and required significantly less injected volume compared to well-established lifting solutions.

A New Ex Vivo Model for the Evaluation of Endoscopic Submucosal Injection Material Performance

Increasing the performance of submucosal injection materials (SIMs) is important for endoscopic therapy of early gastrointestinal cancer. It is essential to establish an ex vivo model that can evaluate SIM performance accurately, for developing high-performance SIMs. In our previous study, we developed a new ex vivo model that can be used to evaluate the performance of various SIMs in detail by applying constant tension to the specimen's ends. We also confirmed that the proposed new ex vivo model allows accurate submucosal elevation height (SEH) measurement under uniform conditions and detailed comparisons of the performances of various types of SIMs. Here, we describe the new ex vivo model and explain the detailed setup methodology of this model. Since all parts of the new model were easy to obtain, the setup of the new model could be completed quickly. SEH of various SIMs could be measured more accurately by using the new model. The critical factor that determines SIM performance can be identified using the new model. SIM development speed will drastically increase after the factor has been identified.

Identification of the critical viscoelastic factor in the performance of submucosal injection materials

High-performance submucosal injection materials (SIMs) contribute to the success of endoscopic therapy for early-stage gastrointestinal neoplasms. This study aimed to identify the most important factor (viscoelastic parameter) that determines SIM performance and the ease of injection. To determine the ideal viscoelastic parameters of SIMs, submucosal elevation heights (SEHs) and the ease of submucosal injection [characterized by injection pressures (IPs)] were evaluated using a newly developed ex vivo model, in which a constant tension was applied to the studied specimen. The strongest positive correlation was observed between the loss modulus determined at an oscillation frequency of 0.1 rad/s and SEH (correlation coefficient > 0.9) and between the loss modulus at 10 rad/s and IP (correlation coefficient > 0.9). SIMs with high loss moduli (0.1 rad/s) also contributed to maintenance of the submucosal elevation. Moreover, the SEHs of pseudoplastic fluid SIMs (whose loss moduli increased slightly with increasing angular frequency) were greater than those of Newtonian fluid SIMs (whose loss modulus increased drastically with increasing angular frequency). In this study, the ideal viscoelastic SIM parameters were clarified. The loss modulus (0.1 rad/s) was the most important viscoelastic factor affecting SIM performance. Additionally, the development of pseudoplastic fluid SIMs may lead to the creation of next-generation SIMs, with a performance superior to that of sodium hyaluronate, which is currently used widely in endoscopic treatments.

A multicenter retrospective study of endoscopic submucosal tunnel dissection for large lesser gastric curvature superficial neoplasms

BACKGROUND AND AIM

Endoscopic submucosal tunnel dissection (ESTD) has been used for dissection of esophageal and gastric lesions. However, outcomes of ESTD for large lesions in the lesser gastric curvature had not been acknowledged because previous reports had the limitations of being single-center studies. We aimed to clarify the outcomes of ESTD for large lesser gastric curvature superficial neoplasms and provide our experience to accelerate its application.

METHODS

Between July 2014 and July 2016, 87 patients with early cancer in the lesser gastric curvature treated at six Chinese institutions were enrolled. Our primary outcome was dissection speed. Moreover, both efficacy and safety clinical data were collected and analyzed retrospectively.

RESULTS

All of the 87 patients were found to successfully undergo ESTD or ESD. Of these, 32 underwent ESTD and 55 underwent endoscopic submucosal dissection (ESD). The ESTD group had a higher dissection speed (18.0 mm²/min vs. 7.8 mm²/min, p < 0.01) and was associated with higher en bloc resection rate (100% vs. 87.3%, p = 0.035) and curative resection rate (100% vs. 85.5%, p = 0.024) compared with the ESD group. No perforation or muscular injury occurred in the ESTD group and its intraprocedural bleeding rate was lower (59.4% vs. 100%, p < 0.01) than that of the ESD group.

CONCLUSIONS

In this multicenter retrospective study, outcomes of ESTD were excellent with a higher dissection speed and radical curative rate compared with ESD.

Optimal injection solution for endoscopic submucosal dissection: A randomized controlled trial of Western solutions in a porcine model

BACKGROUND AND AIM

When carrying out endoscopic submucosal dissection (ESD), procedural safety increases with greater tissue elevation and efficiency increases with longer-lasting submucosal cushion. Fluids specifically developed for ESD in Asia are not commercially available in the West, leaving endoscopists to use a variety of injectable fluids off-label. To determine the optimal fluid available in the West, we compared commonly used fluids for Western ESD.

METHODS

All phases were carried out in an ex vivo porcine stomach model. Phase 1 compared tissue elevation and duration of submucosal cushions produced by various standard volumes of various injectable solutions used for ESD. The two best-performing solutions used off-label were tested head-to-head in ESD in Phase 2. Phase 3 compared the best solution from Phase 2 to Eleview^® , currently the only submucosal injection fluid approved in the USA. In Phases 2 and 3, five ESD were carried out with each solution. The solutions were randomized and the endoscopist blinded to the solution.

RESULTS

The best-performing solutions in Phase 1 were 0.4% hyaluronic acid, 6% hydroxyethyl starch (HES), and Eleview^® . Phase 2 compared 6% HES and hydroxypropyl methylcellulose (HPMC), showing that ESD with 6% HES was easier (P = 0.007), faster (P = 0.041) and required less injection volume (P = 0.003). In Phase 3, resection speed, ease of ESD and total volume per area resected were comparable between 6% HES and Eleview^® .

CONCLUSIONS

Of the submucosal injection fluids currently available in the West, Eleview^® and 6% HES are the best-performing solutions for ESD in a porcine model.

Development of Mucoadhesive Chitosan Derivatives for Use as Submucosal Injections

Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) have been used for surgical treatment of early gastric cancer. These endoscopic techniques require proper submucosal injections beneath the tumor to provide a sufficiently high submucosal fluid cushion (SFC) to facilitate clean dissection and resection of the tumor. Until now, the submucosal injection materials developed for endoscopic techniques such as EMR and ESD of tumors have been composed of macromolecules, proteins, or polysaccharides. We have been investigating the use of chitosan, a product that is obtained by the alkaline deacetylation of chitin, the second-most abundant natural polysaccharide. Specifically, we have been studying a photocrosslinked chitosan hydrogel (PCH) and solubilized chitosan derivatives for use as novel submucosal injections for endoscopic techniques. Notably, chitosan derivatives with lactose moieties linked to the amino groups of its glucosamine units can specifically interact with acidic mucopolysaccharides and mucins in submucosa without the need for the incorporation of harmful photoreactive groups nor potentially mutagenic ultraviolet irradiation.

Development of a new ex vivo model for evaluation of endoscopic submucosal injection materials performance

BACKGROUND AND AIMS

Development of high-performance submucosal injection materials (SIMs) contribute to the advancement of endoscopic therapy for early-stage gastrointestinal neoplasms. This study aimed to develop a new ex vivo model that mimics the human gastrointestinal tract to evaluate the performance (the height and duration of the submucosal elevation) of various SIMs in detail.

METHODS

A new ex vivo model that applies a constant tension to the tested specimen (the porcine gastric specimen) was developed. SIMs were injected into the submucosa at the center or edge of the tested specimen, and submucosal elevation heights (SEHs) were measured over time.

RESULTS

The average value and standard deviation of SEH determined using the conventional model (the tested specimen was fixed with pins) were higher than those obtained using the new model, which showed that the new model could precisely measure the SEH of a given SIM. In addition, the performance (SEH) of SIMs decreased with increasing tension applied to the specimen, suggesting that the performance of SIMs deteriorates with the over-expansion of the gastrointestinal tract. The submucosal elevation formed at the specimen edge disappeared faster than that formed at the specimen's center.

CONCLUSIONS

The proposed new ex vivo model allows accurate SEH measurement under uniform conditions and detailed comparison of the performances of various types of SIMs and can contribute to the development of high-performance materials.

Endoscopic resection of gastric gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors in the gastrointestinal tract, and about 60% of them are found in the stomach. With the widespread application of endoscopy and endoscopic ultrasonography (EUS), more and more gastric GISTs are being found in an early stage (with a relative small diameter and no metastasis), giving the chance of complete resection. Endoscopic resection such as endoscopic band ligation (EBL), endoscopic submucosal dissection (ESD), endoscopic submucosal excavation (ESE), endoscopic full-thickness resection (EFTR) and submucosal tunneling endoscopic resection (STER), is a minimally invasive method compared with the conventional surgical approaches (open or laparoscopic), and has been demonstrated to be safe and effective for treating gastric GISTs. This review summarizes the recent advances on endoscopic resection of gastric GISTs, aiming to provide a rational management strategy for gastric GISTs.

Colorectal endoscopic submucosal dissection (ESD)

Endoscopic submucosal dissection (ESD) is an interventional procedure for en-bloc resection of gastrointestinal lesions. ESD is a challenging and can involve a reasonable degree of risk, therefore case selection is of crucial importance, especially in the colo-rectum. This procedure should be mainly used for dissection of lesions when there is a high suspicion of superficial malignant invasion; several classifications have been proposed in order to better identify lesions suitable for ESD. However, case selection is still an issue, since only about 8-10% of dissected lesions are superficially invading cancer and most of cases involve benign or massively invading cancer. In addition, significant differences have been reported between Asian and Western countries in regard to main outcomes, and therefore measures should be adopted as soon as possible to reduce this discrepancy.

Clinical outcomes after endoscopic submucosal dissection for colorectal neoplasia: a systematic review and meta-analysis

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) is an endoscopic resection technique for lesions suspicious of superficial malignancy. It is performed using an ESD knife on its own (standard technique) or by the sequential use of a knife and a snare (hybrid technique). The experience with these techniques is different in Asian and non-Asian countries. We performed a systematic review and meta-analysis of available evidence on colorectal ESD.

METHODS

Electronic databases were searched up to August 2016 for studies evaluating R0, en bloc resection, and adverse event rates of both techniques for the treatment of colorectal lesions. Proportions were pooled by a random effects model.

RESULTS

Ninety-seven studies (71 performed in Asia) evaluated the standard technique and 12 studies (7 in Asia) the hybrid technique. The R0 resection rate of the standard technique was 82.9%, and it was significantly lower in non-Asian versus Asian countries: 71.3% versus 85.6%. The en bloc resection rate was 91% and was significantly lower in non-Asian versus Asian countries (81.2% vs 93%, respectively). Surgery was needed in 1.1% of the ESD-related adverse events, with a significant difference between non-Asian and Asian countries (3.1% vs 0.8%). The R0 and en bloc resection rates with the hybrid technique were significantly lower than those achieved with the standard technique: 60.6% and 68.4%, respectively, with similar adverse event rates.

CONCLUSIONS

In non-Asian countries the standard ESD technique is still failing to achieve acceptable levels of performance. The hybrid technique showed low R0 resection rates and should not be considered as an adequate alternative to the standard technique.

In situ gelation properties of a collagen-genipin sol with a potential for the treatment of gastrointestinal ulcers

We investigated the potential of collagen-genipin sols as biomaterials for treating artificial ulcers following endoscopic submucosal dissection. Collagen sol viscosity increased with condensation, allowing retention on tilted ulcers before gelation and resulting in collagen gel deposition on whole ulcers. The 1.44% collagen sols containing genipin as a crosslinker retained sol fluidity at 23°C for >20 min, facilitating endoscopic use. Collagen sols formed gel depositions on artificial ulcers in response to body temperature, and high temperature responsiveness of gelation because of increased neutral phosphate buffer concentration allowed for thick gel deposition on tilted ulcers. Finally, histological observations showed infiltration of gels into submucosal layers. Taken together, the present data show that genipin-induced crosslinking significantly improves the mechanical properties of collagen gels even at low genipin concentrations of 0.2-1 mM, warranting the use of in situ gelling collagen-genipin sols for endoscopic treatments of gastrointestinal ulcers.

A laser-induced pulsed water jet for layer-selective submucosal dissection of the esophagus

Background and aims: Conventional water jet devices have been used for injecting fluid to lift up lesions during endoscopic submucosal dissection or endoscopic mucosal resection procedures. However, these devices cannot dissect the submucosal layer effectively. Here we aim to elucidate the dissection capability of a laser-induced pulsed water jet and to clarify the mechanism of dissection with layer selectivity. Materials (Subjects) and methods: Pulsed water jets were ejected from a stainless nozzle by accelerating saline using the energy of a pulsed holmium: yttrium-aluminum-garnet laser. The impact force (strength) of the jet was evaluated using a force meter. Injection of the pulsed jet into the submucosal layer was documented by high-speed imaging. The physical properties of the swine esophagus were evaluated by measuring the breaking strength. Submucosal dissection of the swine esophagus was performed and the resection bed was evaluated histologically. Results: Submucosal dissection of the esophagus was accomplished at an impact force of 1.11-1.47 N/pulse (laser energy: 1.1-1.5 J/pulse; standoff distance: 60 mm). Histological specimens showed clear dissection at the submucosal layer without thermal injury. The mean static breaking strength of the submucosa (0.11 ± 0.04 MPa) was significantly lower than that of the mucosa (1.32 ± 0.18 MPa), and propria muscle (1.45 ± 0.16 MPa). Conclusions: The pulsed water jet device showed potential for achieving selective submucosal dissection. It could achieve mucosal, submucosal, and muscle layer selectivity owing to the varied breaking strengths.

Endoluminal Instrumentation Is Changing Gastrointestinal Surgery

Advances in endoluminal instrumentation and technology are enabling endoscopists to perform increasingly sophisticated procedures. Indications for these procedures are likely to expand as outcomes studies show they are efficacious and cost-effective. This article highlights several recent advances in endoluminal suturing, dissecting, and ligating and discusses the impact of these advances on the practice of gastrointestinal surgery. Endoluminal suturing offers select patients with gastroesophageal reflux disease a safe and effective alternative to laparoscopic surgery. Devices designed for endoluminal hemostasis and endoscopic mucosal resection can be used effectively for a broader range of applications and are already being used to perform transluminal surgery in animal models; human trials are forthcoming. Gastrointestinal surgeons should support efforts to critically evaluate endoluminal techniques because they have an opportunity to improve care. Surgical residents planning careers in gastrointestinal surgery need to understand endoscopic techniques and consider their training opportunities.

Gastric endoscopic submucosal dissection using sodium carboxymethylcellulose as a new injection substance

AIM

To investigate the feasibility of endoscopic submucosal dissection (ESD) using sodium carboxymethylcellulose (SCMC) for gastric cancer.

METHODS

During October 2011 through April 2013, 98 lesions from 98 patients who underwent ESD using SCMC (ESD-SCMC) for early gastric cancer were enrolled in this study.　Two endoscopists, who had each performed fewer than 30 ESD procedures (less-experienced ESD physicians), performed ESD-SCMC under the supervision of two experts.　The primary outcome was the en bloc resection rate.　Secondary outcomes included the complete resection rate, the procedural time, the bleeding rate after SCMC injection, and complications.　Patient characteristics, time necessary for hemostasis after SCMC injection, rate of treatment completion by less-experienced ESD physicians alone, and the effects of SCMC during ESD and on resected specimens were also evaluated.

RESULTS

The en bloc resection rate was 100%.　Among these resections, 87.8% of the cases were completed by a less-experienced ESD physician alone.　The complete resection rate was 98.0%.　The mean total procedural time was 75.4 min.　The mean incidence of intraoperative bleeding following SCMC local injection was 1.7 times.　No bleeding was observed after SCMC injection in 29.6% of cases (29/98).　Five complications occurred: one case of microperforation (1.0%) and four cases of postoperative bleeding (4.0%).　SCMC remained in the submucosa.　The submucosa was readily manipulated when the deep submucosa was dissected, even after placing the specimen on a slide.

CONCLUSION

ESD-SCMC is feasible for the resection of early gastric cancer.

The Evolution of "New Notes," Origins, and Future Directions

The transformation of the submucosa into a working space provided a paradigm shift for endolumenal endoscopic intervention. The submucosal space can provide an undermining access to the removal of overlying mucosal disease. This space can also provide a protective mucosal barrier accommodating interventions into the deep layers of the gut wall and body cavities, such as the abdomen and mediastinum.

What is the best therapeutic strategy for colonoscopy of colorectal neoplasia? Future perspectives from the East

Development and improvement of endoscopic techniques and devices have changed the treatment of colorectal tumors over the last decade. For the treatment of diminutive polyps, the cold snare technique of the West is becoming a promising treatment in the East because of its short procedure time and low rate of delayed bleeding by eliminating the delayed effect of electrocautery. Rather than using piecemeal endoscopic mucosal resection or surgical resection for the treatment of large superficial tumors, the technique of the East of endoscopic submucosal dissection (ESD) achieves a high success rate of en bloc R0 resection, enabling detailed pathological evaluation with less invasive treatment. This procedure should also be useful in the West where large colorectal tumors are more frequent than in the East. Regarding outcomes, however, in the literature, the definition of 'curative resection' remains somewhat inconsistent and long-term outcomes of patients with deep submucosal and/or lymphovascular invasion in the en bloc specimen have not yet been determined. Large prospective, as well as retrospective, studies of these patients are warranted. When colorectal ESD is difficult because of size or location, the pocket-creation method and/or double-balloon-assisted technique may be useful. In the East, high-quality magnified chromoendoscopy is widely available, and endoscopists try to identify focal submucosal invasion. In the West, a systematic evaluation of surveillance for the prevention of colorectal cancer has been done and is highly refined. The East and West have much to learn from each other.

High incidence of metachronous advanced adenoma and cancer after endoscopic resection of colon polyps ≥20 mm in size

BACKGROUND AND AIM

There are limited studies on incidence rates of metachronous neoplastic lesions after resecting large colorectal polyps. In the present study, we analyzed metachronous lesions after endoscopic resection of colorectal polyps ≥20 mm in size.

METHODS

We retrospectively analyzed consecutive patients who underwent endoscopic resection of polyps from 2006 to 2013 at two affiliated hospitals. All patients underwent at least two total colonoscopies before follow up to ensure minimal missed polyps. Only patients who had follow-up colonoscopy annually after resection were recruited. We separated patients according to size of polyp resected; there were 239 patients in the ≥20-mm group and 330 patients in the <20-mm group. Clinical characteristics and cumulative rates of metachronous advanced adenoma and cancer in both groups were analyzed. Advanced adenoma was defined as a neoplastic lesion ≥10 mm in size and adenoma with a villous component.

RESULTS

Cumulative rate of development of metachronous advanced adenoma and cancer in the ≥20-mm group was significantly higher than in the <20-mm group (22.9% vs. 9.5%, P < 0.001) at 36 months. There was also more development of small polyps 5-9 mm in the ≥20-mm group than in the <20-mm group (45.2% vs. 28.8%, P < 0.001). With respect to metachronous lesions, there were more right-sided colonic lesions in the ≥20-mm group than in the <20-mm group (78.8% vs. 50.0%, P = 0.015).

CONCLUSION

High incidence rates of development of metachronous neoplastic lesions were detected after resection of colorectal polyps ≥20 mm in size.

Use of water jet instruments in gastrointestinal endoscopy

In recent years, water jet instruments have been used in the field of gastrointestinal endoscopy, mainly in two clinical situations: Investigation and treatment under endoscopic view. Injecting water jet into the gastrointestinal lumen is helpful for maintaining a clear endoscopic view, washing away blood or mucous in the lumen or on the surface of the tip of the endoscope. This contributes to reducing time and discomfort of examination. Water jet technology is an alternative method for dissecting soft tissue; this method does not harm the small vessels or cause mechanical or thermal damage. However, its use in clinical settings has been limited to the transmucosal injection of water into the submucosal layer that elevates the mucosa to prepare for endoscopic mucosal resection or endoscopic submucosal dissection, instead of tissue dissection, which may occur because of the continuous water jet. A preclinical study has been conducted using a pulsed water jet system as an alternative method for submucosal dissection by reducing intraoperative water consumption and maintenance of dissection capability. This review introduces recent studies pertaining to using a water jet in gastrointestinal endoscopy and discusses future prospects.

IMPROVED EXPERIMENTAL MODEL TO EVALUATE SUBMUCOSAL INJECTION SOLUTIONS FOR ENDOSCOPIC SUBMUCOSAL DISSECTION

Background :

Endoscopic submucosal dissection carries an increased risk of bleeding and perforation. The creation of a long lasting submucosal cushion is essential for the safe and complete removal of the lesion. There is not a suitable experimental model for evaluation of the durability of the cushioning effect of different solutions.

Aim :

To describe an improved experimental model to evaluate submucosal injection solutions.

Methods :

A total of four domestic pigs were employed to evaluate two different submucosal fluid solutions in the gastric submucosa. After midline laparotomy, the anterior gastric wall was incised from the gastric body to the antrum and its mucosal surface was exposed by flipping inside out the incised gastric wall. Two different solutions (10% mannitol and normal saline) were injected in the submucosa of the anterior wall of the distal gastric body. All submucosal cushions were injected until they reach the same size, standardized as 1.0 cm in height and 2.0 cm in diameter. A caliper and a ruler were employed to guarantee accuracy of the measurements.

Results :

All four animal experiments were completed. All submucosal cushions had the exact same size measured with caliper and a ruler. By using the mannitol solution, the mean duration of the submucosal cushion was longer than the saline solution: 20 and 22 min (mean, 21 min) vs 5 and 6 min (mean, 5.5 min)

Conclusions :

This experimental model is simple and evaluate the duration, size, and effect of the submucosal cushion, making it more reliable than other models that employ resected porcine stomachs or endoscopic images in live porcine models.

Usefulness of Ready-to-Use 0.4% Sodium Hyaluronate (Endo-Ease) in the Endoscopic Resection of Gastrointestinal Neoplasms

BACKGROUND/AIMS

Commercially available sodium hyaluronate solutions are usually too thick to inject through catheters and need dilution with normal saline (NS) before use, which increases the risk of contamination. We evaluated the usefulness of ready-to-use 0.4% sodium hyaluronate, Endo-Ease (EE; UNIMED Pharm. Inc., Seoul, Korea).

METHODS

We performed a prospective multicenter randomized study from May 2011 to September 2012. Patients requiring endoscopic resection (ER) for gastric or colorectal neoplasm at two referral hospitals were enrolled.

RESULTS

One hundred fifty-four patients (72 with a gastric neoplasm and 82 with a colorectal neoplasm) were included in intention-to-treat analysis. Thirty-seven gastric neoplasms and 43 colorectal neoplasms were enrolled in the EE group. The usefulness rate was significantly higher in the EE group than in the NS group (89.2% vs. 60.0% for gastric neoplasms and 95.3% vs. 67.7% for colorectal neoplasms, p<0.001). In the EE group, the ease of mucosal resection was significantly higher than in the NS group (p<0.001). The injected volume was smaller in the EE group than in the NS group (p<0.05).

CONCLUSIONS

The use of EE reduced the need for additional injections and improved the ease of ER. A submucosal injection of EE is useful for the ER of both gastric and colorectal neoplasms.

Endoscopic mucosal resection for middle and large colorectal polyps with a double-loop snare

BACKGROUND/AIMS

This study aimed to analyze the endoscopic mucosal resection (EMR) with a novel uniquely shaped, double-loop snare (Dualoop, Medico's Hirata Inc., Tokyo, Japan) for colorectal polyps.

METHODS

This was a clinical trial conducted in two referral centers, Kyoto Prefectural University of Medicine and National Cancer Center Hospital in Japan. First, the firmness of various snares including 'Dualoop' was experimentally analyzed with a pressure gauge. Five hundred and eighty nine consecutive polyps that underwent EMR with 'Dualoop' were compared to 339 polyps with the standard round snare. Lesion characteristics, en bloc resection, and complications were analyzed.

RESULTS

'Dualoop' had the most firmness among the various snares. The average tumor size was 9.3 mm (5-30), and en bloc resection was achieved in 95.4%. The rate of en bloc resection for middle polyps 15-19 mm in diameter was significantly higher with the 'Dualoop' than that with the round snare (97.9 vs. 80.0%, p < 0.05). The rate of en bloc resection was 64.7% for large polyps ≥20 mm in diameter using 'Dualoop'. Higher age, larger tumor size, and superficial polyps were associated with the failure of en bloc resection.

CONCLUSION

EMR with 'Dualoop' was effective for resecting both middle and large polyps en-bloc.

Improved Techniques for Endoscopic Mucosal Resection (EMR) in Colorectal Adenoma

Background

Endoscopic therapy of colorectal adenomas and early cancers is a standard method. Besides oncological criteria, the method is limited by polyp location, size, and texture.

Method

Based on the current literature, technical modifications and developments in endoscopic mucosal resection are described.

Results

Numerous approaches exist to improve the conditions of resection, including optimisation of mucosal elevation and modification of techniques, tools, and devices.

Conclusion

Endoscopic therapy of sessile and flat colorectal polyps remains a challenge. Some of the presented modifications can help to address this challenge.

Preoperative classification of submucosal fibrosis in colorectal laterally spreading tumors by endoscopic ultrasonography

BACKGROUND AND STUDY AIMS

Although endoscopic submucosal dissection (ESD) is an established therapy for colon neoplasms including laterally spreading tumors (LSTs), its application to advanced fibrotic lesions is very difficult owing to the thin walls of the large intestine. We examined the ability of preoperative endoscopic ultrasonography (EUS) to predict lesion fibrosis in patients undergoing colorectal ESD.

PATIENTS AND METHODS

From 2009 to 2013, 58 LSTs were evaluated retrospectively with EUS and treated using colorectal ESD. The degree of submucosal fibrosis was determined during ESD and classified as F0 (no fibrosis), F1 (mild fibrosis), or F2 (severe fibrosis).

RESULTS

The sensitivity and specificity of fibrosis prediction by preoperative EUS of all cases were 77.8 % and 57.1 %, respectively. However, there was a high accuracy (97.2 %, 35/36) for only the 36 LSTs with clear and visible images. In one case, EUS diagnosed no fibrosis but significant fibrosis was found during ESD, the result of colon cancer invasion into the submucosa.

CONCLUSIONS

Preoperative EUS before colorectal ESD successfully predicted the degree of fibrosis in a number of cases.

Improving complete EMR of colorectal neoplasia: a randomized trial comparing snares and injectate in the resection of large sessile colon polyps

BACKGROUND

There are few randomized studies examining efficacy of snares and agents in EMR.

OBJECTIVE

To compare the use of a combined needle and snare unit with injectate versus a spiral wire and injectate (primary); saline solution versus hydroxypropyl methylcellulose (secondary).

DESIGN

Prospective, randomized, factorial, single center.

SETTING

Tertiary-care academic medical center.

PATIENTS

A total of 140 patients with large (>15 mm), sessile, colorectal polyps.

INTERVENTIONS

Polyps randomized to either 1 of 2 snare types and 1 of 2 injectates.

MAIN OUTCOME MEASUREMENTS

Primary-the Sydney resection quotient (SRQ), defined as the size of the polyp divided by the number of pieces resected and the amount of tissue per snare attempt. Secondary-procedure time, adverse events, residual neoplasia at follow-up.

RESULTS

The SRQ was higher with the combined unit (median 13.8 mm vs 7.1 mm; P = .019); additionally, procedure time was less (median 6 vs 11 minutes; P < .001). Resection was considered complete after the EMR in 62% (42/68) with the combined needle and snare unit versus 51% (37/72; P = .22) with the spiral wire. Rates of adverse events were similar. Residual neoplasia was found at follow-up in 22% (10/46) with the combined needle and snare unit versus 21% (10/48; P = .89) with the spiral wire. There was no evidence of differences in outcomes by lifting agent.

LIMITATIONS

The SRQ is only a surrogate marker.

CONCLUSION

This study provides evidence that the integrated needle-snare may be superior to the snare alone for the removal of large, flat polyps. Additionally, the type of injectate appears to have no impact on outcome.