Succinylated gelatin substantially increases en bloc resection size in colonic EMR: a randomized, blinded trial in a porcine model

Submucosal injection fluid and tattoo agents

BACKGROUND AND AIMS

EMR and endoscopic submucosal dissection (ESD) are minimally invasive endoscopic techniques, developed for the removal of benign and early malignant lesions throughout the GI tract. Submucosal injection of a marking agent can help to identify lesions during surgery. Endoscopic resection frequently involves "lifting" of the lesions by injection of a substance within the submucosal space to create a cushion for safe resection. This review summarizes the current techniques and agents available for endoscopic marking and lifting of GI tract lesions.

METHODS

The MEDLINE database was searched through April 2023 for relevant articles related to the lifting and marking aspect of EMR by using key words such as "endoscopy" or "endoscopic" combined with "marking," "tattoo," and "lifting." The report was drafted, reviewed, and edited by the American Society for Gastrointestinal Endoscopy Technology Committee and approved by the Governing Board of the American Society for Gastrointestinal Endoscopy.

RESULTS

This technology review describes the techniques for endoscopic tattoo placement and submucosal lifting, along with currently available agents, safety, and costs.

CONCLUSIONS

Endoscopists performing EMR and ESD have several choices in submucosal injection materials for lifting and marking agents for tattoos. These may be commercially prepared agents or off-the-shelf materials with or without additives to facilitate visualization. A thorough understanding of the indications, techniques, properties of various agents, costs, and adverse events is necessary in choosing the appropriate materials and technique to optimize lesion resection in EMR and ESD.

Colorectal polypectomy and endoscopic mucosal resection: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2024

1:  ESGE recommends cold snare polypectomy (CSP), to include a clear margin of normal tissue (1-2 mm) surrounding the polyp, for the removal of diminutive polyps (≤ 5 mm).Strong recommendation, high quality of evidence. 2:  ESGE recommends against the use of cold biopsy forceps excision because of its high rate of incomplete resection.Strong recommendation, moderate quality of evidence. 3:  ESGE recommends CSP, to include a clear margin of normal tissue (1-2 mm) surrounding the polyp, for the removal of small polyps (6-9 mm).Strong recommendation, high quality of evidence. 4:  ESGE recommends hot snare polypectomy for the removal of nonpedunculated adenomatous polyps of 10-19 mm in size.Strong recommendation, high quality of evidence. 5:  ESGE recommends conventional (diathermy-based) endoscopic mucosal resection (EMR) for large (≥ 20 mm) nonpedunculated adenomatous polyps (LNPCPs).Strong recommendation, high quality of evidence. 6:  ESGE suggests that underwater EMR can be considered an alternative to conventional hot EMR for the treatment of adenomatous LNPCPs.Weak recommendation, moderate quality of evidence. 7:  Endoscopic submucosal dissection (ESD) may also be suggested as an alternative for removal of LNPCPs of ≥ 20 mm in selected cases and in high-volume centers.Weak recommendation, low quality evidence. 8:  ESGE recommends that, after piecemeal EMR of LNPCPs by hot snare, the resection margins should be treated by thermal ablation using snare-tip soft coagulation to prevent adenoma recurrence.Strong recommendation, high quality of evidence. 9:  ESGE recommends (piecemeal) cold snare polypectomy or cold EMR for SSLs of all sizes without suspected dysplasia.Strong recommendation, moderate quality of evidence. 10:  ESGE recommends prophylactic endoscopic clip closure of the mucosal defect after EMR of LNPCPs in the right colon to reduce to reduce the risk of delayed bleeding.Strong recommendation, high quality of evidence. 11:  ESGE recommends that en bloc resection techniques, such as en bloc EMR, ESD, endoscopic intermuscular dissection, endoscopic full-thickness resection, or surgery should be the techniques of choice in cases with suspected superficial invasive carcinoma, which otherwise cannot be removed en bloc by standard polypectomy or EMR.Strong recommendation, moderate quality of evidence.

Curriculum for training in endoscopic mucosal resection in the colon: European Society of Gastrointestinal Endoscopy (ESGE) Position Statement

Endoscopic mucosal resection (EMR) is the standard of care for the complete removal of large (≥ 10 mm) nonpedunculated colorectal polyps (LNPCPs). Increased detection of LNPCPs owing to screening colonoscopy, plus high observed rates of incomplete resection and need for surgery call for a standardized approach to training in EMR. 1 : Trainees in EMR should have achieved basic competence in diagnostic colonoscopy, < 10-mm polypectomy, pedunculated polypectomy, and common methods of gastrointestinal endoscopic hemostasis. The role of formal training courses is emphasized. Training may then commence in vivo under the direct supervision of a trainer. 2 : Endoscopy units training endoscopists in EMR should have specific processes in place to support and facilitate training. 3: A trained EMR practitioner should have mastered theoretical knowledge including how to assess an LNPCP for risk of submucosal invasion, how to interpret the potential difficulty of a particular EMR procedure, how to decide whether to remove a particular LNPCP en bloc or piecemeal, whether the risks of electrosurgical energy can be avoided for a particular LNPCP, the different devices required for EMR, management of adverse events, and interpretation of reports provided by histopathologists. 4: Trained EMR practitioners should be familiar with the patient consent process for EMR. 5: The development of endoscopic non-technical skills (ENTS) and team interaction are important for trainees in EMR. 6: Differences in recommended technique exist between EMR performed with and without electrosurgical energy. Common to both is a standardized technique based upon dynamic injection, controlled and precise snare placement, safety checks prior to the application of tissue transection (cold snare) or electrosurgical energy (hot snare), and interpretation of the post-EMR resection defect. 7: A trained EMR practitioner must be able to manage adverse events associated with EMR including intraprocedural bleeding and perforation, and post-procedural bleeding. Delayed perforation should be avoided by correct interpretation of the post-EMR defect and treatment of deep mural injury. 8: A trained EMR practitioner must be able to communicate EMR procedural findings to patients and provide them with a plan in case of adverse events after discharge and a follow-up plan. 9: A trained EMR practitioner must be able to detect and interrogate a post-endoscopic resection scar for residual or recurrent adenoma and apply treatment if necessary. 10: Prior to independent practice, a minimum of 30 EMR procedures should be performed, culminating in a trainer-guided assessment of competency using a validated assessment tool, taking account of procedural difficulty (e. g. using the SMSA polyp score). 11: Trained practitioners should log their key performance indicators (KPIs) of polypectomy during independent practice. A guide for target KPIs is provided in this document.

Design and biopharmaceutical preclinical characterisation of a new thermosensitive hydrogel for the removal of gastric polyps

BACKGROUND AND AIMS

Submucosal injection agents are widely used solutions in gastric polyp resection techniques. Currently, many different solutions are used in clinical practice, but most are not authorised for this use or are not biopharmaceutical characterised. The objective of this multidisciplinary work is to test the efficacy of a novel thermosensitive hydrogel designed specifically for this indication.

METHODS

A mixture design of various components (Pluronic®, hyaluronic acid and sodium alginate) was carried out to select the combination with optimal properties for this use. Three final thermosensitive hydrogels were selected on which biopharmaceutical characterisation was performed and stability and biocompatibility were analysed. Efficacy in maintaining elevation was tested ex vivo on pig mucosa and in vivo in pigs RESULTS: The mixture design allowed selection of the ideal combinations of agents for the characteristics sought. The thermosensitive hydrogels studied showed high values of hardness and viscosity at 37 °C, maintaining good syringeability. One of them demonstrated superiority in maintaining polyp elevation in the ex vivo assay and non-inferiority in the in vivo assay.

CONCLUSION

The thermosensitive hydrogel specifically designed for this use is promising both for its biopharmaceutical characteristics and for its demonstrated efficacy. This study lays the foundation for evaluating the hydrogel in humans.

Interventional gastroenterology in oncology

Cancer is one of the foremost health problems worldwide and is among the leading causes of death in the United States. Gastrointestinal tract cancers account for almost one third of the cancer-related mortality globally, making it one of the deadliest groups of cancers. Early diagnosis and prompt management are key to preventing cancer-related morbidity and mortality. With advancements in technology and endoscopic techniques, endoscopy has become the core in diagnosis and management of gastrointestinal tract cancers. In this extensive review, the authors discuss the role endoscopy plays in early detection, diagnosis, and management of esophageal, gastric, colorectal, pancreatic, ampullary, biliary tract, and small intestinal cancers.

Histopathological effects of electrosurgical interventions in an in vivo porcine model of colonic endoscopic mucosal resection

OBJECTIVE

Endoscopic mucosal resection (EMR) in the colon has been widely adopted, but there is limited data on the histopathological effects of the differing electrosurgical currents (ESCs) used. We used an in vivo porcine model to compare the tissue effects of ESCs for snare resection and adjuvant margin ablation techniques.

DESIGN

Standardised EMR was performed by a single endoscopist in 12 pigs. Two intersecting 15 mm snare resections were performed. Resections were randomised 1:1 using either a microprocessor-controlled current (MCC) or low-power coagulating current (LPCC). The lateral margins of each defect were treated with either argon plasma coagulation (APC) or snare tip soft coagulation (STSC). Colons were surgically removed at 72 hours. Two specialist pathologists blinded to the intervention assessed the specimens.

RESULTS

88 defects were analysed (median 7 per pig, median defect size 29×17 mm). For snare ESC effects, 156 tissue sections were assessed. LPCC was comparable to MCC for deep involvement of the colon wall. For margin ablation, 172 tissue sections were assessed. APC was comparable to STSC for deep involvement of the colon wall. Islands of preserved mucosa at the coagulated margin were more likely with APC compared with STSC (16% vs 5%, p=0.010).

CONCLUSION

For snare resection, MCC and LPCC did not produce significantly different tissue effects. The submucosal injectate may protect the underlying tissue, and technique may more strongly dictate the depth and extent of final injury. For margin ablation, APC was less uniform and complete compared with STSC.

Applicability of Monocyte Activation Test for Pyrogen Detection in Succinylated Gelatin Injection

Background::

Pyrogens are fever-inducing substances and pyrogen detection is mandatory in parenteral pharmaceuticals. Succinylated Gelatin Injection (SGI) is a biopharmaceutical product, containing multi-component, and it is administered parenterally.

Objective:

The study aimed to assess pyrogen in SGI and to evaluate the feasibility of the Monocyte Activation Test (MAT) for pyrogen detection in a multi-component pharmaceutical product.

Method:

In the present study, the Bacterial Endotoxin Test (BET) and the Monocyte Activation Test (MAT) were employed to assess pyrogen in SGI. The MAT method was developed on the basis of the HL-60/IL-6 assay. HL-60 cells were incubated with lipopolysaccharide (LPS) standards and sample solutions. The endotoxin produced by the incubation, interleukin-6 (IL-6), was measured by ELISA. The MAT method was validated and main parameters were investigated. Finally, the pyrogenicity of SGIs from two different enterprises was determined by the developed MAT method.

Results:

The BET failed in the test for interfering factors and the MAT was proved suitable for the pyrogen detection of SGI. All the products examined showed negative results in the pyrogen detection test.

Conclusion:

The MAT method is feasible in pyrogen detection of SGI. It can be applied in pyrogen detection for quality and safety control of multi-component biological products.

Efficacy and Safety of a Novel Submucosal Injection Solution for Resection of Gastrointestinal Lesions

Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are minimally invasive and efficient techniques for the removal of gastrointestinal (GI) mucosal polyps. In both techniques, submucosal injection solutions are necessary for complete effectiveness and safety during the intervention to be obtained. The main objective of this study was to evaluate the efficacy and safety of a new sterile submucosal injection solution for EMR/ESD used within a clinical protocol in patients with intestinal polyps. We carried out a prospective study between 2016 and 2017 with patients who attended the Endoscopy Consultation—Digestive Department of Primary Hospital. Patients were selected for EMR/ESD after the application of clinical protocols. Thirty-six patients were selected (≥ 66 years with comorbidities and risk factors). Lesions were located mainly in the colon. Our solution presented an intestinal lift ≥ 60 min in EMR/ESD and a high expansion of tissue, optimum viscosity, and subsequent complete resorption. The genes S100A9 and TP53 presented an expression increase in the distal regions. TP53 and PCNA were the only genes whose expression was increased in polyp specimens vs. the surrounding tissue at the mRNA level. In EMR/ESD, our solution presented a prolonged effect at the intestinal level during all times of the intervention. Thus, our solution seems be an effective and safe alternative in cases of flat lesions in both techniques.

Novel Polymeric Formulation for Removal of Gastrointestinal Polyps by Digestive Endoscopy

Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are two techniques used in the resection of gastrointestinal mucosal polyps. The aim of this work is the development and evaluation of an innovative polymeric solution containing sodium carboxymethylcellulose and hyaluronic acid. For this purpose, several mixtures of these two main components, as well as other components such as fructose, citric acid, and zinc, are evaluated in terms of physicochemical and microbiological properties, rheological behavior, extensibility, syringeability, and stability at different storage conditions. Furthermore, the potential production of mucosal elevation and duration is also studied by an ex vivo model using porcine stomach and colon. Results show that the developed polymeric solutions possess optimal values of pH, from 4.58 to 6.63, for their use in the gastrointestinal tract. The formulations exhibit both Newtonian and pseudoplastic behaviors with different viscosity values as a function of their composition. All formulations exhibit high stability properties and no bacterial or fungal growth is detected. MCS01 and MCS05 are the polymeric solutions with the best syringeability results. In this line, MCS05 is the formulation that provides the highest, 2.20 ± 0.18 cm and 1.40 ± 0.11 cm, and longest-lasting, for more than 120 min, elevation effect on porcine submucosal stomach and colon tissues, respectively. Thus, it can be concluded that polymeric solution MCS05 might be considered as a promising tool for use in human EMR and ESD.

Successful outcomes of a new combined solution of hyaluronic acid, chondroitin sulfate and poloxamer 407 for submucosal injection: animal survival study

Background and study aims  Endoscopic resection requires use of submucosal injection. This study was conducted to assess efficacy and impact on early healing of hyaluronic acid combined with chondroitin sulfate and poloxamer 407 (Ziverel) when used as a solution for submucosal injection. Materials and methods  Prospective and comparative study of gastric endoscopic mucosal resection (EMR) with three groups of two Yorkshire pigs. Six submucosal cushions were created in each animal by injecting 2 mL of Ziverel (Group 1) or succinylated gelatin (SG) (Group 2), enabling 12 EMR in each group. Submucosal cushions were created with Ziverel in Group 3, without resection. Electrosurgery unit settings were the same in all cases. EMR defects and injection sites were marked with clips. The animals were sacrificed 7 days later. EMR specimen size and duration of procedure were recorded. EMR specimens and EMR scars and injection sites were evaluated by a blinded pathologist. Results  We successfully performed 24 EMR (15 en-bloc and 9 piecemeal, without differences between groups 1 and 2). Mean EMR specimen dimensions were significantly larger in Group 1 (median 19 mm, range 6 - 40 vs 16.6 mm, range 5‑25; P  = 0.019), without changing the electrocautery unit settings. Blinded histopathologist assessment of EMR specimens showed less fibrosis in the submucosa and a trend to fewer cautery artifacts with Ziverel and did not identify any significant differences in early healing of resection sites. Conclusion  The combination of Ziverel enables EMR and does not negatively affect early healing.

Endoscopic detection and resection of dysplasia in inflammatory bowel disease-techniques with videos

BACKGROUND

Patients with ulcerative colitis and Crohn's colitis have an increased risk of developing dysplasia and colorectal cancer as compared to the general population; surveillance colonoscopy is recommended in this patient population.

METHODS

This review of the published literature aimed to assess the published evidence.

RESULTS

Detection of dysplasia requires examination of mucosa with targeted biopsies of the visible lesions as well as random biopsies to detect invisible lesions. Newer endoscopic techniques, in particular chromoendoscopy, increase the yield of identifying dysplastic lesions. The surveillance for Colorectal Endoscopic Neoplasia Detection and Management in Inflammatory Bowel Disease Patients International Consensus (SCENIC) guidelines recommends that colonoscopy using chromoendoscopy is the optimal endoscopic surveillance strategy to detect dysplasia. Once dysplastic lesions are discovered on surveillance endoscopic examination, careful and meticulous descriptions of lesions is mandatory to aid in further decision making. Management of dysplastic lesions in inflammatory bowel disease patients depends on endoscopic (morphological) and histologic findings and patient characteristics such as age, general condition of the patient, and patient preferences. Endoscopic mucosal resection, endoscopic submucosal dissection, and surgery are different therapeutic options for colonic dysplastic lesions detected in the setting of inflammatory bowel disease.

CONCLUSIONS

In this review, we discuss the various techniques for endoscopic resection of dysplasia in patients with inflammatory bowel disease. Further research is required to determine the optimal approach to diagnosis and management of dysplasia in patients with inflammatory bowel disease.

A novel submucosal injection solution for endoscopic resection of large colorectal lesions: a randomized, double-blind trial

BACKGROUND AND AIMS

SIC-8000 (Eleview) is a new U.S. Food and Drug Administration (FDA)-approved solution for submucosal injection developed to provide a long-lasting cushion to facilitate endoscopic resection maneuvers. Our aim was to compare the efficacy and safety of SIC-8000 with those of saline solution, when performing EMR of large colorectal lesions.

METHODS

In a randomized double-blind trial, patients undergoing EMR for colorectal non-pedunculated lesions ≥20 mm were randomized in a 1:1 ratio between SIC-8000 and saline solution as control solution in 5 tertiary centers. Endoscopists and patients were blinded to the type of submucosal solution used. Total volume to complete EMR and per lesion size and time of resection were primary endpoints; the Sydney Resection Quotient (SRQ), as well as other EMR outcomes, and the rate of adverse events were secondary endpoints. A 30-day telephone follow-up was performed. An alpha level <0.05 was considered as statistically significant.

RESULTS

Of the 327 patients screened, 226 (mean age, 66 ± 10 years; males, 56%) were enrolled in the study and randomized between the 2 submucosal agents. Of these, 211 patients (mean size of the lesions 33 ± 13 mm; Paris class Is, 36%; proximal colon, 74%) were entered in the final analysis (SIC-8000, 102; saline solution, 109). EMR was complete in all cases. The total volume needed for EMR was significantly less in the SIC-8000 arm compared with saline group (16.1 ± 9.8 mL vs 31.6 ± 32.0 mL; P < .001). This corresponded to an average volume per lesion size of 0.5 ± 0.3 mL/mm and 0.9 ± 0.6 mL/mm with SIC-8000 and saline solution, respectively (P < .001). The mean time to completely resect the lesion tended to be lower with SIC-8000 than with saline solution (19.1 ± 16.8 minutes vs 29.7 ± 68.9 minutes; P = .1). The SRQ was significantly higher with SIC-8000 compared with saline solution (10.3 ± 8.1 vs 8.0 ± 5.7; P = .04) with a trend for a lower number of resected pieces (5.7 ± 6.0 vs 6.5 ± 5.04; P = .052) and a higher rate of en bloc resections (19/102, 18.6% vs 12/111, 11.0%; P = .1). The rate of adverse events was similar between the 2 arms (SIC-8000, 18.6%; saline solution, 17%), and none of the serious adverse events (SIC-8000, 8.8%; saline solution, 10.7%) were related to the study treatment.

CONCLUSIONS

In a double-blind, randomized clinical trial, a new FDA-approved agent for sub-mucosal injection appeared to be a more effective and equally safe submucosal agent for EMR injection than saline solution. (Clinical trial registration number: NCT02654418.).

Efficacy and safety of SIC-8000 (Eleview®) for submucosal injection for endoscopic mucosal resection and endoscopic submucosal dissection in an in vivo porcine model

BACKGROUND

Submucosal injection is generally required for both endoscopic-mucosal resection (EMR) and submucosal dissection (ESD). SIC-8000 (Eleview™) is a new FDA 510(k) cleared and CE marked liquid composition for submucosal injection, containing a biocompatible polymer as a cushioning agent.

AIMS

The aim of this randomized study was to compare Eleview with saline solution when performing upper- and lower-GI EMR/ESD in a porcine model.

METHODS

EMR/ESD procedures were performed in a total of 10 white domestic pigs comparing Eleview vs. NaCl 0.9% containing methylene blue at 0.001% (control solution) as submucosal solution to be injected. Animals were randomized between EMR (22 procedures) and ESD (22 procedures) and between upper- (8 animals) and lower-(2 animals) GI procedures. All procedures were performed aiming for a resection size of 1 cm × 1 cm for EMR and 2 cm × 2 cm for ESD. Volume of injected fluid, number of injections, time of resection, technical success, en-bloc resection, and adverse events were collected. Endoscopic surveillance was conducted each week for 4 weeks after the EMR/ESD, including biopsies on the margins of resection sites at week-1 of follow-up. After four weeks, pigs were sacrificed and necropsy performed.

RESULTS

Overall, 22 EMR and 22 ESD were performed in 10 live pigs. The average total volume needed for EMR and ESD was statistically significantly lower with Eleview as compared with control solution for both of the techniques (EMR: 5.6 ± 3.4 ml vs. 11.5 ± 6.7 ml; p = 0.02; ESD: 19.0 ± 10.0 ml vs. 36.3 ± 16.9 ml; p = 0.02). The rate of adverse events was statistically significantly lower in the Eleview than in the control group (2/26, 7.7% vs. 6/18, 33.3%; p = 0.03), but most of them were minor. No difference between Eleview and control solution was found in the rate of technical success (EMR: 11/13, 84.6% vs. 7/9, 77.8%; p = 0.7; ESD: 13/13, 100% vs. 9/9, 100%; p = 1), en-bloc resection (EMR: 6/13, 46.2% vs. NaCl: 5/9, 55.6%; p = 0.06; ESD: 12/13, 92.3% vs. 8/9, 88.9%; p = 0.8), and time of resection (EMR: 9.1 ± 7.75 min vs. 9.4 ± 9.6 min; p = NS; ESD: 38.4 ± 17.2 min vs. 40.2 ± 19.1 min; p = NS). At endoscopic follow up and necropsy, no difference in the process of healing of post-endoscopic ulcer and in the histological inflammation at the site of resection was shown between the two groups.

CONCLUSIONS

The new submucosal injection composition Eleview appeared to be an effective alternative to saline solution for submucosal injection for EMR/ESD, resulting in a substantial reduction of the volume administered to achieve an adequate lifting. No signs of adverse local or distant tissue reaction to Eleview were found at long-term follow up.

Standard needle versus needleless injection modality: animal study on different fluids for submucosal elevation

BACKGROUND AND AIMS

Submucosal injection is currently used in GI endoscopy to reduce resection risks and to perform submucosal dissection; it is usually performed via an injection needle or a needleless device. The aim of the study was to compare 2 submucosal injection modalities (needle-assisted vs needleless) by using substances with different viscosities.

METHODS

Needle and needleless injections were compared by assessing the efficacy of tissue elevation with 5 different substances in an ex vivo porcine model. The height of the submucosal elevation was measured 0(t0), 10(t1), and 30 minutes after injection (t2). Viscosity of the solution was also measured.

RESULTS

For both stomach and rectum, at t0, t1, and t2 no difference in the height of the elevation was found between the needle and needleless technique, irrespective of the substance. Tissue elevation in the stomach was similar between the 2 techniques at t0 (9.9 ± 1.58 vs 9.4 ± 1.3 mm, P = .3), t1 (7.2 ± 1.56 vs 6.9 ± 1.4 mm, P =. 26), and t2 (6 ± 1.6 vs 5.5 ± 1.3 mm, P = .18). No difference was found in the rectum at t1 and t2, whereas a slightly higher elevation with the needle-assisted technique was observed at t0 (t0: 12.4 ± 1.3 vs 11.2 ± 1.6 mm, P = .003; t1: 8.7 ± 1.3 vs 8.3 ± 1.5 mm; P = .32; t2: 7.0 ± 1.4 vs 7.2 ± .76 mm; P = .75). When comparing the substances with normal saline solution, more viscous solutions showed a significantly higher elevation at t0, t1, and t2 irrespective of the injection modalities and the location.

CONCLUSIONS

No differences were found in the height of submucosal injection or in the persistence of such elevation when comparing needleless with needle-assisted injection, with the only minor exception of the initial elevation in the rectum, which does not appear to be clinically relevant. Viscous solutions resulted in higher and more persistent elevations as compared with normal saline solution.

Standardisation of polypectomy technique

There are several approaches to polypectomy for sessile polyps <20 mm and for pedunculated polyps. Recent evidence is leading towards standardisation of polypectomy technique. Key recent polypectomy developments include: 1. Use of cold snare polypectomy (CSP) for sessile polyps <10 mm; 2. Use of hot snare polypectomy (HSP) following submucosal injection for sessile polyps sized 10-19 mm; 3. Piecemeal cold snare polypectomy (PCSP), with or without prior submucosal injection, for select sessile polyps sized 10-19 mm, where the potential risk for an adverse event is increased (e.g. polyps in the caecum or ascending colon, or patients with increased risk of post-polypectomy bleeding), and where the risk of submucosal invasion is low; 4. Avoidance of hot biopsy forceps (HBF); 5. Limiting the use of cold biopsy forceps (CBF) to the smallest of diminutive polyps, where CSP is not feasible; 6. Mechanical haemostasis prior to polypectomy for large pedunculated polyps with head ≥20 mm or stalk ≥10 mm.

Extended endoscopic mucosal resection does not reduce recurrence compared with standard endoscopic mucosal resection of large laterally spreading colorectal lesions

BACKGROUND AND AIMS

Effective interventions to prevent residual and/or recurrent adenoma (RRA) after EMR of large sessile and laterally spreading colorectal lesions (LSL) are yet to be determined. RRA may occur due to inconspicuous adenoma at the EMR margin. We aimed to determine the efficacy and safety of extended EMR (X-EMR) compared with standard EMR (S-EMR).

METHODS

A single-center post hoc analysis of LSL ≥20 mm referred for treatment was performed. S-EMR was the standard sequential inject and resect method including a 1-mm to 2-mm margin of normal mucosa around the lesion. With X-EMR, at least a 5-mm margin of normal mucosa was excised. Patient and lesion characteristics and procedural outcomes were recorded. The primary endpoint was RRA at first surveillance colonoscopy at 4 months.

RESULTS

Between January 2009 and May 2011, 471 lesions (mean size, 37.9 mm) in 424 patients were resected by S-EMR, and between January 2012 and December 2013, 448 lesions (mean size, 39.1 mm) in 396 patients were resected by X-EMR. Resection was successful in 92.3% and 92.6% of referred lesions in the S-EMR and X-EMR groups, respectively (P = .978). X-EMR was independently associated with a higher risk of intraprocedural bleeding (IPB) (odds ratio, 3.1; 95% confidence interval [CI], 2.0-5.0; P < .001) but not other adverse events. RRA was present in 39 of 333 patients (11.7%) and 30 of 296 patients (10.1%) in the S-EMR and X-EMR groups, respectively (P = .15). X-EMR was not related to recurrence (hazard ratio, 0.8; 95% CI, 0.5-1.3; P = .399).

CONCLUSIONS

X-EMR does not reduce RRA and increases the risk of IPB compared with S-EMR. Alternative methods for the prevention of RRA are required.

Prediction of Clinically Significant Bleeding Following Wide-Field Endoscopic Resection of Large Sessile and Laterally Spreading Colorectal Lesions: A Clinical Risk Score

OBJECTIVES

Clinically significant bleeding (CSPEB) is the most frequent adverse event following wide-field endoscopic mucosal resection (WF-EMR) of large sessile and laterally spreading colorectal lesions (LSL). There is limited knowledge regarding accurate prediction of CSPEB. We aimed to derive a score to predict the risk of CSPEB.

METHODS

Data on patient and lesion characteristics and outcomes from WF-EMRs of LSL ≥20 mm at 8 referral hospitals were analyzed. The cohort was divided at random into equal sized training and test groups. Independent predictors of CSPEB in the training cohort were identified by multiple logistic regression analysis and used to develop a risk score. The performance of this score was assessed in the independent test cohort.

RESULTS

Over 80 months to June 2015, 2,128 patients with 2,424 LSL were referred for WF-EMR. Two thousand and twelve patients were eligible for analysis. There were 135 cases of CSPEB (6.7%). In the training cohort of 1,006 patients, the independent predictors of CSPEB were lesion size >30 mm (odds ratio (OR) 2.5), proximal colonic location (OR 2.3), presence of a major comorbidity (OR 1.5), and epinephrine in injection solution (OR 0.57). The derived risk score comprised lesion size >30 mm (2 points), proximal colon (2 points), presence of major comorbidity (1 point), and absence of epinephrine use (1 point). The probabilities of CSPEB for scores of 0, 1, 2, 3, 4, and ≥5 in the training cohort were 1.5, 2.0, 5.6, 7.8, 9.1, and 17.5% and were 0.9, 6.7, 4.9, 6.2, 9.0, and 15.7% in the test cohort. The probabilities of CSPEB in those with low (score 0-1), medium (score 2-4), and elevated (score 5-6) risk levels were 1.7, 7.1, and 17.5% in the training cohort and 3.4, 6.2, and 15.7% in the test cohort.

CONCLUSIONS

Patients at elevated risk of CSPEB can be identified using four readily available variables. This knowledge may improve the management of those undergoing WF-EMR and assist in designing studies evaluating CSPEB.

Endoscopic mucosal resection and endoscopic submucosal dissection of large colonic polyps

Almost all large and complex colorectal polyps can now be resected endoscopically. Piecemeal endoscopic mucosal resection (PEMR) is an established technique with fairly low complication risk and good short-term and medium-term outcomes. Several modifications to the basic injection and snare technique have been developed contributing to safer and more complete resections. Delayed bleeding requiring reintervention is the most troublesome complication in 2-7% of patients, particularly in those with comorbidities and large, right-sided polyps. Endoscopic submucosal dissection (ESD) has become popular in Japan and has theoretical advantages over PEMR in providing a complete, en bloc excision for accurate histological staging and reduced local recurrence. These advantages come at the cost of a more complex, expensive and time-consuming procedure with a higher risk of perforation, particularly early in the procedure learning curve. These factors have contributed to the slow adoption of ESD in the West and the challenge to develop new devices and endoscopic platforms that will make ESD easier and safer. Currently, ESD indications are limited to large rectal lesions, in which procedural complications are easily managed, and for colorectal polyps with a high risk of containing tiny foci of early submucosally invasive cancer, whereby ESD may be curative compared with PEMR.

Solutions for submucosal injection in endoscopic resection: a systematic review and meta-analysis

BACKGROUND AND AIMS

Submucosal injection is standard practice in endoscopic mucosal resection of gastrointestinal lesions. Several solutions are used. Our aim was to systematically review their efficacy and safety.

PATIENTS AND METHODS

We performed a systematic review and meta-analysis using a random effects model of randomized controlled trials (RCTs) from MEDLINE. Studies in animal models were qualitatively assessed for efficacy and safety.

RESULTS

In total, 54 studies were qualitatively assessed. Eleven RCTs were analyzed, two of which were on endoscopic submucosal dissection (ESD). The quantitative synthesis included nine RCTs on endoscopic mucosal resection (EMR), comprising 792 subjects and 793 lesions. Mean lesion size was 20.9 mm (range 8.5 - 46 mm). A total of 209 lesions were randomized to sodium hyaluronate (SH) vs normal saline (NS), 72 to 50 % dextrose (D50) vs NS, 82 to D50 vs SH, 43 to succinylated gelatin, 25 to hydroxyethyl starch and 36 to fibrinogen. In total, 385 were randomized to NS as controls. NS and SH are the best studied solutions and seem to be equally effective in achieving complete resection (OR 1.09; 95 %CI 0.82, 1.45). No solution was proven to be superior in complete resection rate, post-polypectomy bleeding or coagulation syndrome/perforation incidence. Many solutions have been tested in animal studies and most seem more effective for mucosal elevation than NS.

CONCLUSIONS

There are several solutions in clinical use and many more under research, but most are poorly studied. SH seems to be clinically equivalent to NS. There are no significant differences in post-polypectomy complications. Larger RCTs are needed to determine any small differences that may exist between solutions.

British Society of Gastroenterology/Association of Coloproctologists of Great Britain and Ireland guidelines for the management of large non-pedunculated colorectal polyps

These guidelines provide an evidence-based framework for the management of patients with large non-pedunculated colorectal polyps (LNPCPs), in addition to identifying key performance indicators (KPIs) that permit the audit of quality outcomes. These are areas not previously covered by British Society of Gastroenterology (BSG) Guidelines.A National Institute of Health and Care Excellence (NICE) compliant BSG guideline development process was used throughout and the Appraisal of Guidelines for Research and Evaluation (AGREE II) tool was used to structure the guideline development process. A systematic review of literature was conducted for English language articles up to May 2014 concerning the assessment and management of LNPCPs. Quality of evaluated studies was assessed using the Scottish Intercollegiate Guidelines Network (SIGN) Methodology Checklist System. Proposed recommendation statements were evaluated by each member of the Guideline Development Group (GDG) on a scale from 1 (strongly agree) to 5 (strongly disagree) with >80% agreement required for consensus to be reached. Where consensus was not reached a modified Delphi process was used to re-evaluate and modify proposed statements until consensus was reached or the statement discarded. A round table meeting was subsequently held to finalise recommendations and to evaluate the strength of evidence discussed. The GRADE tool was used to assess the strength of evidence and strength of recommendation for finalised statements.KPIs, a training framework and potential research questions for the management of LNPCPs were also developed. It is hoped that these guidelines will improve the assessment and management of LNPCPs.

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.

Polidocanol injection decreases the bleeding rate after colon polypectomy: a propensity score analysis

BACKGROUND

EMR is the standard of care for the resection of large polyps.

OBJECTIVE

To compare the efficacy and safety profile of submucosal polidocanol injection with epinephrine-saline solution injection for colon polypectomy with a diathermic snare.

DESIGN

After 1-to-1 propensity score caliper matching, comparison of submucosal epinephrine injection was performed with polidocanol injection.

SETTING

Endoscopic suite at the University of Foggia between 2005 and 2014.

PATIENTS

Of 711 patients who underwent endoscopic resection of colon sessile polyps 20 mm or larger, 612 were analyzed after matching.

INTERVENTIONS

Submucosal epinephrine injection in 306 patients and polidocanol injection in 306 patients.

MAIN OUTCOME MEASUREMENTS

Univariate and multivariate logistic regression models aimed at identifying independent predictors of postpolypectomy bleeding (PPB).

RESULTS

The 2 groups presented similar baseline clinical parameters and lesion characteristics. All patients had a single polyp 20 mm or larger; the median size was 32 mm (interquartile range [IQR], 25-38) in the polidocanol group and 32 (IQR, 24-38) in the epinephrine group (P=.7). Polidocanol was more effective in preventing both immediate and delayed PPB (P<.001 and P=.003, respectively), and its efficacy was confirmed in almost all of the subgroups, regardless of polyp size and histology. Postprocedure perforation was observed in 2 patients (0.3%), both in the epinephrine group (P=.49). The 2 groups did not differ in the number of snare resections of lesions or the procedure duration (P=.24 and .6, respectively).

LIMITATIONS

Absence of randomization.

CONCLUSION

The submucosal injection of polidocanol for colon EMR is effective and significantly lowers the PPB rate.

Prophylactic endoscopic coagulation to prevent bleeding after wide-field endoscopic mucosal resection of large sessile colon polyps

BACKGROUND & AIMS

Clinically significant postendoscopic mucosal resection bleeding (CSPEB) is the most frequent significant complication of wide-field endoscopic mucosal resection (WF-EMR) of advanced mucosal neoplasia (sessile or laterally spreading colorectal lesions > 20 mm). CSPEB requires resource-intensive management and there is no strategy for preventing it. We investigated whether prophylactic endoscopic coagulation (PEC) reduces the incidence of CSPEB.

METHODS

We performed a prospective randomized controlled trial of 347 patients (mean age, 67.1 y; 55.3% with proximal colonic lesions) undergoing WF-EMR for advanced mucosal neoplasia at 3 Australian tertiary referral centers. Patients were assigned randomly (1:1) to groups receiving PEC (n = 172) or no additional therapy (n = 175, controls). PEC was performed with coagulating forceps, applying low-power coagulation to nonbleeding vessels in the resection defect. CSPEB was defined as bleeding requiring admission to the hospital. The primary end point was the proportion of CSPEB.

RESULTS

Patients in each group were similar at baseline. CSPEB occurred in 9 patients receiving PEC (5.2%) and 14 controls (8.0%; P = .30). CSPEB was associated significantly with proximal colonic location on multivariate analysis (odds ratio, 3.08; P = .03). Compared with the proximal colon, there was a significantly greater number (3.8 vs 2.1; P = .002) and mean size (0.5-1 vs 0.3-0.5 mm; P = .04) of visible vessels in the distal colon.

CONCLUSIONS

PEC does not significantly decrease the incidence of CSPEB after WF-EMR. There were significantly more and larger vessels in the WF-EMR mucosal defect of distal colonic lesions, yet CSPEB was more frequent with proximal colonic lesions. ClinicalTrials.gov NCT01368731.

Long-term adenoma recurrence following wide-field endoscopic mucosal resection (WF-EMR) for advanced colonic mucosal neoplasia is infrequent: results and risk factors in 1000 cases from the Australian Colonic EMR (ACE) study

OBJECTIVE

Wide-field endoscopic mucosal resection (WF-EMR) is an alternative to surgery for treatment of advanced colonic mucosal neoplasia up to 120 mm in size, but has been criticised for its potentially high recurrence rates. We aimed to quantify recurrence at 4 months (early) and 16 months (late) following successful WF-EMR and identify its risk factors and clinical significance.

DESIGN

Ongoing multicentre, prospective, intention-to-treat analysis of sessile or laterally spreading colonic lesions ≥20 mm in size referred for WF-EMR to seven academic endoscopy units. Surveillance colonoscopy (SC) was performed 4 months (SC1) and 16 months (SC2) after WF-EMR, with photographic documentation and biopsy of the scar.

RESULTS

1134 consecutive patients were enrolled when 1000 successful EMRs were achieved, of whom 799 have undergone SC1. 670 were normal. Early recurrent/residual adenoma was present in 128 (16.0%, 95% CI 13.6% to 18.7%). One case was unknown. The recurrent/residual adenoma was diminutive in 71.7% of cases. On multivariable analysis, risk factors were lesion size >40 mm, use of argon plasma coagulation and intraprocedural bleeding. Of 670 with normal SC1, 426 have undergone SC2, with late recurrence present in 17 cases (4.0%, 95% CI 2.4% to 6.2%). Overall, recurrent/residual adenoma was successfully treated endoscopically in 135 of 145 cases (93.1%, 95% CI 88.1% to 96.4%). If the initial EMR was deemed successful and did not contain submucosal invasion requiring surgery, 98.1% (95% CI 96.6% to 99.0%) were adenoma-free and had avoided surgery at 16 months following EMR.

CONCLUSIONS

Following colonic WF-EMR, early recurrent/residual adenoma occurs in 16%, and is usually unifocal and diminutive. Risk factors were identified. Late recurrence occurs in 4%. Overall, recurrence was managed endoscopically in 93% of cases. Recurrence is not a significant clinical problem following WF-EMR, as with strict colonoscopic surveillance, it can be managed endoscopically with high success rates.

TRIAL REGISTRATION NUMBER

NCT01368289.

Endoscopic management of nonpolypoid colorectal lesions in colonic IBD

Much of the flat or biopsy-only detected dysplasia in inflammatory bowel disease (IBD) that had historically warranted a colectomy can now be shown to be circumscribed lesions with dye-spray or advanced endoscopic imaging. These lesions are therefore amenable to endoscopic excision with close endoscopic follow-up, though are technically very challenging. This review discusses preresection assessment of nonpolypoid or flat (Paris 0-II) lesions in colitis; lifting with colloids or hyaluronate; endoscopic mucosal resection (EMR) with spiral or flat ribbon snares; or simplified, hybrid, and full endoscopic submucosal dissection (ESD); as well as mucosal ablation. Close follow-up postresection is mandatory.

Colonoscopic polypectomy: current techniques and controversies

Colonoscopic polypectomy is fundamental to effective colonoscopy. Through its impact on the polyp-cancer sequence, colonoscopic polypectomy reduces colorectal cancer incidence and mortality. Because it eliminates electrosurgical risk, cold snaring has emerged as the preferred technique for most small and all diminutive polyps. Few clinical trial data are available on the effectiveness and safety of specific techniques. Polypectomy technique seems highly variable between endoscopists, with some techniques more effective than others are. Further research is needed to investigate operator variation in polypectomy outcomes and establish an evidence base for best practice.

Colon polypectomy: a review of routine and advanced techniques

The value of performing comprehensive screening colonoscopy with complete colon polypectomy is widely accepted. Colon cancer is a significant cause of worldwide mortality and prospective studies have proven that colonoscopic polypectomy reduces both the incidence and mortality related to this disease. Over the past few decades the array of instruments and techniques have greatly expanded to assist with the safe endoscopic removal of colon polyps. This article will review the published literature regarding efficacy and safety of standard polypectomy techniques such as snare polypectomy, electrocautery, and endoscopic mucosal resection along with newer techniques such as endoscopic submucosal dissection and combined laparoscopic techniques.

Multicenter study of endoscopic mucosal resection using 0.13% hyaluronic acid solution of colorectal polyps less than 20 mm in size

PURPOSE

Endoscopic mucosal resection (EMR) of colorectal polyps should be curative and safe. This study aimed to determine the efficacy and safety of colorectal EMR using 0.13% hyaluronic acid (HA) solution.

METHODS

This was a single-armed multicenter prospective open trial conducted at 11 Japanese institutions. Lesion characteristics and various measures of clinical outcome, including en bloc resection, histopathologically complete resection, and postoperative bleeding were analyzed for 624 consecutive patients who underwent EMR of colorectal polyps at ≤20 mm in size from August 2010 to September 2011.

RESULTS

En bloc and complete resection were achieved in 93.3 and 78.3% of 624 lesions. The median EMR procedure time was 2.1 ± 1.5 min. The rates of postoperative bleeding and perforation were 1.1 and 0%. The rate of en bloc resection was higher for polyps at 5-10 mm than for polyps at 11-20 mm (95.1 vs. 85.1%; P < 0.001) and was higher for protruding polyps than for superficial polyps (94.5 vs. 87.1%; P < 0.05). The rate of en bloc resection was also higher for polyps in the left-side colon than for those in the right-side colon or rectum (96.7 vs. 91.6 vs. 90.8%; P < 0.05). Multivariate analysis showed that polyp at 11-20 mm in size and location not on the left-side colon was significantly independent risk factors for failure of en bloc resection.

CONCLUSION

EMR using 0.13% HA of colorectal polyps less than 20 mm in size had high rates of en bloc and complete resection and few complications.

A novel gel provides durable submucosal cushion for endoscopic mucosal resection and endoscopic submucosal dissection

BACKGROUND

Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) have transformed the ability to endoscopically remove superficial lesions throughout the gastrointestinal tract. The purpose of this study was to determine the properties and safety of a novel gel designed for the purpose of submucosal injection for EMR and ESD.

METHODS

Upper endoscopy was performed in six Yorkshire pigs with 5-8 submucosal injections of varying amounts of Cook Medical (Bloomington, IN) gel were delivered in the stomach of each animal. A submucosal bleb of 1-2 ml normal saline was created followed by subsequent injection of 1-5 ml of the gel. Four animals were immediately euthanized and necropsy was performed after gel delivery and in two pigs; repeat endoscopy was performed after 4 weeks followed by necropsy.

RESULTS

Thirty-nine submucosal injections were performed in six pigs. Every injection resulted in adequate mucosal lifting with a shoulder and defined margin and no cases of gel extravasation. Twenty-seven injections were performed in four pigs followed by immediate necropsy. The submucosal cushion was still present at the time of organ extraction without evidence of perforation, bleeding or tissue damage. Unroofing of the mucosal layer demonstrated a clean submucosal tissue dissection without bleeding or tissue damage. Twelve submucosal injections were performed in two pigs, and repeat endoscopy at 4 weeks demonstrated persistent submucosal cushion without evidence of mucosal ischemia or ulceration. Necropsy demonstrated no evidence of perforation, bleeding, or gel extravasation. Unroofing the mucosa confirmed a clean submucosal dissection. The injectate did not result in mesenteric fibroinflammatory reaction, tissue damage, or adhesion formation after 4 weeks.

CONCLUSIONS

The gel appears to be a safe injectate that provides a submucosal cushion with a duration that is longer than other available injectates for EMR and ESD. The clean submucosal dissection may decrease the length of these procedures while minimizing complications.

Carbon dioxide insufflation reduces number of postprocedure admissions after endoscopic resection of large colonic lesions: a prospective cohort study

BACKGROUND

Endoscopic resection (ER) for large colonic lesions is a safe and effective outpatient treatment. Postprocedural pain creates concern for perforation and often results in postprocedure admission (PPA). Carbon dioxide (CO(2)) insufflation has been shown to reduce pain scores after routine colonoscopy, but an influence on more critical outcomes such as PPA has not been shown.

OBJECTIVE

To assess the outcomes of patients undergoing ER for large colonic lesions, comparing those having air versus those having CO(2) insufflation.

DESIGN

Prospective, observational, cohort study.

SETTING

Academic, high-volume, tertiary-care referral center.

PATIENTS

Consecutive patients referred for ER of sessile colorectal polyps ≥20 mm.

INTERVENTION

ER with air or CO(2).

MAIN OUTCOME MEASUREMENTS

Rates of PPA, technical outcomes, complication rates.

RESULTS

ER was performed on 575 lesions ≥20 mm, 228 with CO(2) insufflation. Mean lesion size was 36.5 mm. Lesion and patient characteristics were similar in both groups. The use of CO(2) was associated with a 62% decrease in the PPA rate from 8.9% to 3.4% (P = .01). This was mainly because of an 82% decrease in PPA for pain from 5.7% to 1.0% (P = .006). There were no significant difference in the rates of complications. Multiple logistical regression was performed. The adjusted odds ratio (OR) of PPA (OR 0.39; 95% confidence interval [CI], 0.16-0.95; P = .04) and PPA for pain (OR 0.18; 95% CI, 0.04-0.78; P = .02) in the CO(2) group remained significant.

LIMITATIONS

Single center, nonrandomized study.

CONCLUSION

CO(2) insufflation significantly reduces PPA after ER of large colonic lesions, primarily because of reduced PPA for pain. CO(2) insufflation should be routinely used during ER of large colonic lesions.

Wide field endoscopic resection for advanced colonic mucosal neoplasia: current status and future directions

Most colonic adenomas are ≤ 10 mm and are routinely treated by colonoscopic polypectomy with long-term health benefits. Nonpolypoid lesions ≥ 20 mm, whether sessile or flat and laterally spreading, are forms of advanced mucosal neoplasia that cannot be managed by conventional polypectomy and are often referred for surgery. However, the majority of these lesions when carefully assessed are found to be noninvasive and can be safely and effectively treated by advanced endoscopic techniques including endoscopic mucosal resection or endoscopic submucosal dissection with resultant cost, morbidity, and mortality benefits. Lesion assessment is a critical component. Enhanced imaging methods provide the opportunity for accurate pathological characterization, informing treatment decisions, without the need for previous histologic confirmation. Techniques of advanced endoscopic resection are still in evolution and further improvements, including hybrid techniques, bringing less technically challenging and shorter procedures with superior safety can be reasonably expected in the next decade. Safety is a fundamental consideration. Methods of early recognition of complications, risk stratification, and management pathways are being developed and refined. Standardization, validation, and adoption of these technological developments will improve endoscopic interpretation and therapy and in combination with an increased understanding of adenoma molecular biology, will result in a progressively more individualized lesion-specific endoscopic approach. The future of advanced endoscopic resection in the colon is promising, and the next few years should see the boundaries of endoscopic resection expand well beyond the limits of what we know today.

Endoscopic mucosal resection with 0.13% hyaluronic acid solution for colorectal polyps less than 20 mm: a randomized controlled trial

BACKGROUND AND AIM

Adequate mucosal elevation by submucosal injection is important for definitive en bloc resection and prevention of perforation during endoscopic mucosal resection (EMR). The objective of this study is to determine the efficacy of 0.13% hyaluronic acid (HA) solution for high and sustained mucosal elevation during colorectal EMR.

METHODS

The study was a prospective randomized controlled trial; a total of 196 patients with colon polyps of < 20 mm diameter were enrolled and randomized in a 1:1 ratio to undergo EMR using either 0.13% HA or normal saline (NS). The primary outcome of the study was histopathologically confirmed complete resection. The secondary outcomes such as maintenance of high mucosal elevation and development of complications were also evaluated. Moreover, the relationship between complete resection and the experience of the endoscopist (veteran vs less experienced) was analyzed.

RESULTS

Compete resection was achieved in 74 of 93 polyps (79.5%) in the 0.13% HA group and 63 of 96 polyps (65.6%) in the NS group (P < 0.05). High mucosal elevation was maintained in 83.9% of procedures in the 0.13% HA group and 54.1% in the NS group (P < 0.01). The frequency of complete resection achieved by less-experienced endoscopists was higher in the 0.13% HA group (79.3%) than in the NS group (62.1%; P < 0.05).

CONCLUSIONS

Endoscopic mucosal resection using 0.13% HA to colon polyps of less than 20 mm diameter is more effective than NS for complete resection and maintenance of mucosal elevation.

Beyond the snare: technically accessible large en bloc colonic resection in the West: an animal study

BACKGROUND

Endoscopic submucosal dissection (ESD) and circumferential submucosal incision endoscopic mucosal resection (CSI-EMR) are techniques for en bloc excision of large sessile colonic lesions. Our aims were to compare the efficacy, safety and learning curve of colonic hybrid knife (HK) ESD versus CSI-EMR for en bloc excision of 50 mm diameter hemi-circumferential artificial lesions in a porcine model.

PATIENTS AND METHODS

Two separate 50 mm diameter areas of normal recto-sigmoid mucosa were marked out in each of ten pigs. One was excised with HK-ESD using succinylated gelatin (SG) submucosal injection. The other was isolated with CSI with the Insulated Tip Knife 2 followed by SG submucosal injection then EMR with a large snare. Euthanasia and colectomy was performed at 72 h followed by blinded histopathology assessment.

RESULTS

En bloc excision rates were: HK-ESD 100% versus CSI-EMR 20% (P = 0.008). The mean number of resections per lesion was HK-ESD 1 versus CSI-EMR 3 (P = 0.001). The mean dimensions of the largest specimen per technique were HK-ESD 63 × 54 mm versus CSI-EMR 49 × 41 mm (P = 0.005). Procedure duration mean was HK-ESD 54 min versus CSI-EMR 22 min (P < 0.001). When procedure duration was adjusted for the size of the resected en bloc specimen, a statistically significant and accelerated learning effect was noted for HK-ESD (r = -0.83, P = 0.003). There were no perforations and no significant bleeding.

CONCLUSIONS

HK-ESD with SG submucosal injection is superior to CSI-EMR for en bloc excision of 50 mm diameter lesions in a porcine model. The technique is rapidly learnt. This novel approach may lower the barrier to colonic ESD for Western endoscopists.

Endoscopic colorectal imaging and therapy

PURPOSE OF REVIEW

Colorectal cancer screening and prevention is a pivotal element in every gastroenterologist practice. Recent advances in imaging technology and treatment opened the field for endoscopic management of large flat colorectal polyps and early cancer.

RECENT FINDINGS

High-definition white light colonoscopy allowed for better characterization of colon polyps, particularly flat lesions. Chromoendoscopy facilitated the identification of colon polyps as well as better endoscopic polyp characterization, with strong correlation with final pathological diagnosis, opening the field of 'virtual' biopsy. One particular technology, confocal endomicroscopy can magnify an image approximately 1000 times resembling optical microscopy with very good correlation with histology. Endoscopic mucosal resection has gained great acceptance to manage flat colorectal polyps with the two major complications being bleeding and perforation, both now under 5% in experienced hands. Endoscopic submucosal resection was developed to increase en-bloc resection (less residual disease) of a flat colorectal lesion but one has to accept a higher perforation rate around 10%.

SUMMARY

Current technology allows for better polyp identification and characterization, which can be managed endoscopically.

The target sign: an endoscopic marker for the resection of the muscularis propria and potential perforation during colonic endoscopic mucosal resection

BACKGROUND

EMR of large sessile polyps and laterally spreading tumors (LSTs) of the colon is safe and cost-effective. Perforation remains a feared and well-recognized complication; however, endoscopic detection is often absent, and most commonly, diagnosis is delayed and depends on clinical signs and/or radiology findings. To date, an endoscopic sign to identify muscularis propria (MP) resection and potential perforation has not been described.

OBJECTIVE

To describe an endoscopic sign for prompt recognition of EMR-related MP resection.

DESIGN

Prospective analysis.

SETTINGS

Tertiary referral academic gastroenterology unit.

PATIENTS

Patients with the target sign were identified prospectively in 2 large prospective studies of EMR for colonic LSTs 20 mm or larger.

INTERVENTION

A standardized EMR approach was used. MP defects were closed endoscopically with clips.

MAIN OUTCOME MEASUREMENTS

The presence or absence of the target sign in the polypectomy specimen and its influence on subsequent endoscopic management of polypectomy complications.

RESULTS

A total of 445 patients with LSTs or sessile polyps 20 mm or larger (mean size 33 mm, range 20-85 mm) were prospectively enrolled in 2 studies. Ten patients (mean age 70.3 years, range 48-83 years, 50% male) with target lesions and histologically confirmed MP resection were identified prospectively at the time of EMR, with 3 having full-thickness resection. All cases were identified intraprocedurally by a target sign on the underside of the specimen and a mirror target evident in the mucosal defect. All patients were treated endoscopically with 1 to 5 endoscopic clips. None required operative management. Thirteen inpatient days were required to treat the 10 patients (mean 1.3 days).

LIMITATIONS

Nonrandomized study.

CONCLUSIONS

Careful analysis of the post-EMR specimen and resection defect may reveal a target sign, an easily recognized and reliable marker of either partial- or full-thickness MP resection and potential perforation. Prompt recognition of this sign facilitates endoscopic management.

A randomized, double-blind trial of succinylated gelatin submucosal injection for endoscopic resection of large sessile polyps of the colon

OBJECTIVES

Succinylated gelatin (SG) is an inexpensive, safe, colloidal solution. It was superior to normal saline (NS) in a porcine colon endoscopic resection (ER) model. Our aim was to compare the efficacy, efficiency, and safety of ER with SG vs. NS.

METHODS

A randomized double-blind trial of submucosal injection with SG vs. NS was conducted for patients undergoing colonoscopy and ER for sessile lesions ≥20 mm in size at an Australian academic hospital endoscopy unit. The primary end point was the "Sydney Resection Quotient" (SRQ), defined as "lesion size in mm divided by the number of pieces to resect." This allows a comparison of technical outcomes for lesions of various sizes. A large lesion removed in fewer pieces gives a greater value.

RESULTS

Eighty patients (45 men, mean age 69) with lesions sized 20-100 mm were randomized. A total of 41 SG subjects were well matched to 39 NS subjects, with median (interquartile range) lesion size 40 mm (25-45) vs. 35 mm (30-50), respectively (P=0.382). Complete single-session lesion excision was 90% in both groups. There were no adverse events attributable to SG. The SRQ (median (interquartile range)) was SG 10.0 (7.5-20.0) vs. NS 5.9 (4.4-11.7), P=0.004. Other end points (median (interquartile range)) included fewer resections per lesion in the SG group: 3.0 (1.0-6.0) vs. NS 5.5 (3.0-10.0), P=0.028; fewer injections per lesion with SG: 2.0 (1.0-3.0) vs. NS 3.0 (2.0-11.0), P=0.002; lower injection volume: 14.5 ml (8.5-23.0) vs. NS 20.0 ml (16.0-46.0), P=0.009; and shorter procedure duration with SG: 12.0 min (8.0-28.0) vs. NS 24.5 min (15.0-36.0), P=0.006.

CONCLUSIONS

SG significantly improves SRQ by almost halving the number of resections for piecemeal ER. SG also safely halves procedure duration.