Usefulness of sodium hyaluronate solution in colorectal endoscopic mucosal resection

Hypertonic solution as an optimal submucosal injection solution for endoscopic resection of gastrointestinal mucosal lesions: Systematic review and network meta-analysis

OBJECTIVES

Based on different physicochemical properties, common submucosal injection solutions could be classified into three categories: normal saline solution (NS), hypertonic solution (HS), and viscous solution (VS). We compared the efficacy and safety of various categories of solutions in this network meta-analysis of randomized controlled trials (RCTs) to identify the optimal submucosal injection fluid.

METHODS

PubMed, Embase, Web of Science, and the Cochrane Library were searched for RCTs that compared the efficacy and safety of NS, HS, and VS during endoscopic resection for gastrointestinal (GI) mucosal lesions. Pairwise and network analyses were conducted to determine the ranking of different fluids.

RESULTS

Thirteen RCTs were included in the final analysis with 1637 patients (1639 lesions). HS outperformed NS in rates of en bloc (pooled relative risk [RR] 1.50; 95% confidence interval [CI] 1.10-1.90), overall bleeding (pooled odds ratio [OR] 0.33; 95% CI 0.10-0.88; lesions >10 mm OR 4.65 × 10-2; 95% CI 1.10 × 10-3-0.46), and intraoperative bleeding (lesions >10 mm OR 7.10 × 10-6; 95% CI 4.30 × 10-18-0.26). HS showed the highest probability of ranking first in each outcome except for the volume of injection. Although VS was superior to NS in rates of en bloc, overall, and intraoperative bleeding in the lesions >10 mm subgroup, and required less fluid in pooled analysis, it ranked last in cost of submucosal injection solution.

CONCLUSIONS

Both HS and VS were superior to NS in comparisons of efficacy and safety. Considering the better performance and potentially low cost, HS might be an optimal choice during gastrointestinal endoscopic resection, especially for colorectal endoscopic mucosal resection.

Efficacy and safety of a submucosal injection solution of sodium alginate for endoscopic resection in a porcine model

Endoscopic resection techniques require the use of submucosal injection. Normal saline and sodium hyaluronate solutions are mainly used for this purpose, but an ideal solution has not yet been developed. The aim of this study was to assess a new solution, MC-003-a novel submucosal injection solution developed with sodium alginate as the main ingredient. Normal saline, a commercial sodium hyaluronate solution (Endo-Ease), and MC-003 were examined. A total of 18 gastric submucosal cushions were created in the stomachs of six pigs. The height of mucosal elevation was measured sequentially using endoscopic sonography. After euthanizing the animals either 2 h or 5 days after the procedure, pathologic examination was performed for each injection site. Although not statistically significant over the entire study period, MC-003 showed a superior result to normal saline and an equivalent result to Endo-Ease in the submucosal cushion height and its rate of decrease. There were no adverse outcomes after injection of the three solutions and there was no pathologically identified detrimental change in the resected specimens. MC-003 creates a sufficient submucosal fluid cushion without apparent tissue damage. It can be considered as an effective submucosal injection material.

MucoUp® as a spacer in brachytherapy for uterine cervical cancer: A first-in-human experience

We first used MucoUp®, a hyaluronic acid used in endoscopic resection, as a spacer in brachytherapy. In five cervical cancer patients, MucoUp® insertion increased a 90% dose of the high-risk CTV to over 80 Gy while decreasing the dose of organs at risk. No related adverse events were observed.

Preventing Postendoscopic Mucosal Resection Bleeding of Large Nonpedunculated Colorectal Lesions

The most common major adverse event of endoscopic mucosal resection (EMR) is clinically significant post-EMR bleeding (CSPEB), with an incidence of 6%-7% in large lesions. Repeat colonoscopy, blood transfusions, or other interventions are often needed. The associated direct costs are much higher than those of an uncomplicated EMR. In this review, we discuss the aspects related to CSPEB of large nonpedunculated polyps, such as risk factors, predictive models, and prophylactic measures, and we highlight evidence for preventive treatment options and explore new methods for bleeding prophylaxis. We also provide recommendations for steps that can be taken before, during, and after EMR to minimize bleeding risk. Finally, this review proposes future directions to reduce CSPEB incidence.

Randomized controlled trial investigating use of submucosal injection of EverLift™ in rates of complete resection of non-pedunculated 4-9 mm polyps

INTRODUCTION

Currently, cold snare polypectomy (CSP) without submucosal injection is recommended for removing polyps < 10 mm. Use of viscous submucosal agents has not been previously evaluated in CSP. We investigate the potential role of EverLift™ (GI Supply, Pennsylvania) in CSP.

METHODS

The study is a single-center prospective randomized non-inferiority clinical trial evaluating CSP of non-pedunculated 4-9 mm polyps, with or without submucosal injection of EverLift™. Patients 18-80 years of age presenting for colonoscopy were recruited. Eligible polyps underwent block randomization to CSP with or without EverLift™. Following CSP, two biopsies were performed at the CSP site margin. The primary non-inferiority outcome was complete resection rate, defined by absence of residual polyp in the margin biopsies (non-inferiority margin -10%).

RESULTS

A total of 291 eligible polyps underwent CSP, with 142 removed using EverLift™. There was similar polyp size and distribution of pathology between the two groups. Overall, there was a low rate of positive margins with (1.4%) or without submucosal injection (2.8%), with no significant difference in complete resection (difference 1.28%, 95% CI: -2.66 to 5.42%), demonstrating non-inferiority of EverLift™ injection. Use of EverLift™ significantly increased CSP time (109.8 vs 38.8 s, p < 0.0001) and frequency of use of hemostatic clips (13.4 vs 3.6%, p = 0.002).

CONCLUSION

Submucosal injection of EverLift™ was non-inferior to CSP of 4-9 mm polyps without injection and increased time for resection as well as use of hemostatic clips to control acute bleeding. Our results suggest that polypectomy of 4-9 mm polyps can be safely performed without submucosal injection of EverLift™.

Fever and electrocoagulation syndrome after colorectal endoscopic submucosal dissection for patients with immunosuppressants and steroids

Objectives

Transient fever and electrocoagulation syndrome after colorectal endoscopic submucosal dissection (ESD) remain a challenge. The aim of this study was to assess the risk factors of post‐ESD fever and post‐ESD coagulation syndrome (PECS), focusing on the involvement of immunosuppressive drugs and steroids (IM).

Methods

This retrospective analysis included 510 patients who underwent colorectal ESD at Okayama University Hospital from 2015 to 2020. The incidence rate, clinical outcome, and factors associated with post‐ESD fever and PECS were investigated.

Results

Post‐ESD fever and PECS occurred in 63 patients (12.4%) and 43 patients (8.4%), respectively. In multivariate analysis, the American Society of Anesthesiologists Physical Status ≥3, the use of immunosuppressants or prednisolone ≥5mg (IM group), and injury to muscle layer/perforation were significantly associated with post‐ESD fever. In PECS, IM group, tumors located on the right side, treatment time ≥60 min, injury to the muscle layer, and multiple lesions were independent risk factors. Both post‐ESD fever and PECS improved conservatively in the IM group, and no serious complication was observed.

Conclusions

The use of IM was a risk factor for both post‐ESD fever and PECS. However, there were no serious complications in colorectal ESD for patients taking IM.

Comparison of sodium alginate-based and sodium hyaluronate-based submucosal injection materials based on rheological analysis

As a viscous high-performance submucosal injection material (SIM) used in endoscopic submucosal dissection (ESD), sodium alginate-based SIM (SA-SIM) was recently introduced as high-performance SIM equivalent to sodium hyaluronate-based SIM (HA-SIM) in Japan. However, a comprehensive, detailed comparison of SA and HA is yet to be performed. In this study, we precisely measured the viscoelastic properties, submucosal elevation height (SEH), and injection pressure (IP). Furthermore, we compared the outcomes of ESD using an ex vivo ESD model. There was no significant difference in SEHs between HA-SIM and SA-SIM at all post-injection times, and the IP of the SA-SIM injection was significantly higher than that of the HA-SIM injection in all conditions (P < 0.0001). The viscosity at high shear rates of SA-SIM was higher than that of HA-SIM; this result was consistent with SEH/IP measurement results. No significant difference was observed in ESD procedure time and total volume of injected SIM between HA-SIM and SA-SIM (18.1 ± 6.7 and 17.8 ± 6.0 min, P = 0.8987; 13.3 ± 5.3 and 11.6 ± 5.9 ml, P = 0.4658, respectively). Although SA-SIM was slightly more difficult to inject than HA-SIM, there was no significant difference in performance between the materials. Thus, this basic study demonstrated that SA-SIM can be used for endoscopic treatment as well as HA-SIM, and supported previous clinical research data.

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.

Endoscopic clipping for gastrointestinal bleeding: emergency and prophylactic indications

Endoscopic clipping has become a common practice among endoscopists. Several models are available, most frequently being introduced via the working channel of the endoscope (through-the-scope); however, larger clips can also be mounted onto the distal tip of the endoscope (over-the-scope). The main indications for endoclip placement include providing effective mechanical hemostasis for bleeding lesions and allowing endoscopic closure of gastrointestinal perforations. Endoclips can also be used prophylactically after endoscopic resection; however, this practice is still controversial. This review discusses the main indications for endoscopic clipping in the esophagus, stomach, duodenum and colon to manage acute bleeding lesions, and the criteria to be used in the prevention of delayed post-polypectomy bleeding.

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.

Novel technique for endoscopic en bloc resection (EMR+) - Evaluation in a porcine model

BACKGROUND

Endoscopic en bloc resection of larger polyps is relevant because risk of advanced neoplasia or malignancy correlates with tumor size. Recurrence rates after piecemeal endoscopic mucosal resection (EMR) are high and endoscopic submucosal dissection (ESD) is associated with higher complication rates in the western world.

AIM

To develop a modified endoscopic en bloc resection technique using an external additional working channel and novel agent for submucosal injection.

METHODS

EMR+ was considered as modified grasp and snare technique. For simultaneous use of a grasping and cutting device a novel additional working channel was used (AWC^®, Ovesco Endoscopy, Tübingen, Germany). AWC^® is installed on the outer surface of the endoscope, covered with a plastic sleeve and designed for single use. For submucosal injection a new agent consisting of poloxamers was used (LiftUp^®, Ovesco Endoscopy, Tübingen, Germany). The agent is liquid at room temperature and forms a stable and permanent gel cushion after injection. Safety of LiftUp^® has been shown in a pre-clinical study in domestic pigs. LiftUp^® is commercially not yet available but approval is expected in early 2019. EMR+ was first developed ex vivo (explanted pig stomach) and subsequently evaluated in vivo (stomach, porcine model, 3 domestic pigs). Main outcome measurements were: Procedure time, macroscopic en bloc resection and adverse events.

RESULTS

Concept of EMR+ was first developed ex vivo (explanted pig stomach). Ex vivo, 22 resections were performed after technique was established. Median procedure time (measured from begin of injection to extraction of resection specimen) was 7 min (range 5-11, SD 1.68) and median size of resection specimens was 30 mm × 26 mm × 11 mm ex vivo. Subsequently 13 resections were performed in vivo (stomach, porcine model, 3 domestic pigs). In vivo, median procedure time (measured from begin of injection to extraction of resection specimen) was 5 min (range 3-12, SD 2.72) and median size of resection specimens was 35 mm × 35 mm × 11 mm. In vivo, resection was macroscopic complete in 92.3%, major adverse events were not observed. In one case (7.7%) minor periprocedural bleeding was observed and managed by coagulation.

CONCLUSION

EMR+ appeared to be effective and safe and was easy and fast to perform in the porcine model. EMR+ needs to be further evaluated clinically in comparative trials.

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.

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.

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.

Colorectal endoscopic mucosal resection (EMR)

Colonoscopy has the benefit of detecting and treating precancerous adenomatous polyps and thus reduces mortality associated with CRC. Screening colonoscopy is the keystone for prevention of colorectal cancer. Over the last 20 years there has been increased in the management of large colorectal polyps from surgery to endoscopic removal techniques which is less invasive. Traditionally surgical resection was the treatment of choice for many years for larger polyps but colectomy poses significant morbidity of 14-46% and mortality of up to 7%. There are several advantages of endoscopic resection technique over surgery; it is less invasive, less expensive, has rapid recovery, and preserves the normal gut functions. In addition patient satisfaction and efficacy of EMR is higher with minor complications. Thus, this has facilitated the development of advanced resection technique for the treatment of large colorectal polyps called as endoscopic mucosal resection (EMR).

Normal saline solution versus other viscous solutions for submucosal injection during endoscopic mucosal resection: a systematic review and meta-analysis

BACKGROUND AND AIMS

EMR is being increasingly practiced for the removal of large colorectal polyps. A variety of solutions such as normal saline solution (NS) and other viscous and hypertonic solutions (VS) have been used as submucosal injections for EMR. A systematic review and meta-analysis is presented comparing the efficacy and adverse events of EMR performed using NS versus VS.

METHODS

Two independent reviewers conducted a search of all databases for human, randomized controlled trials that compared NS with VS for EMR of colorectal polyps. Data on complete en bloc resection, presence of residual lesions, and adverse events were extracted using a standardized protocol. Pooled odds ratio (OR) estimates along with 95% confidence intervals (CI) were calculated using fixed effect or random effects models.

RESULTS

Five prospective, randomized controlled trials (504 patients) met the inclusion criteria. The mean polyp sizes were 20.84 mm with NS and 21.44 mm with VS. On pooled analysis, a significant increase in en bloc resection (OR, 1.91; 95% CI, 1.11-3.29; P = .02; I² = 0%) and decrease in residual lesions (OR, 0.54; 95% CI, 0.32-0.91; P = .02; I² = 0%) were noted in VS compared with NS. There was no significant difference in the rate of overall adverse events between the 2 groups.

CONCLUSIONS

Use of VS during EMR leads to higher rates of en bloc resection and lower rates of residual lesions compared with NS, without any significant difference in adverse events. Endoscopists could consider using VS for EMR of large colorectal polyps and NS for smaller polyps because there is no significant difference in the outcomes with lesions <2 cm.

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.

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.

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.

Endoscopic mucosal resection

EMR has become an established therapeutic option for premalignant and early-stage GI malignancies, particularly in the esophagus and colon. EMR can also aid in the diagnosis and therapy of subepithelial lesions localized to the muscularis mucosa or submucosa. Several dedicated EMR devices are available to facilitate these procedures. Adverse event rates, particularly bleeding and perforation, are higher after EMR relative to other basic endoscopic interventions but lower than adverse event rates for ESD. Endoscopists performing EMR should be knowledgeable and skilled in managing potential adverse events resulting from EMR.

Non-polypoid colorectal neoplasms: Classification, therapy and follow-up

In the last years, an increasing interest has been raised on non-polypoid colorectal tumors (NPT) and in particular on large flat neoplastic lesions beyond 10 mm tending to grow laterally, called laterally spreading tumors (LST). LSTs and large sessile polyps have a greater frequency of high-grade dysplasia and local invasiveness as compared to pedunculated lesions of the same size and usually represent a technical challenge for the endoscopist in terms of either diagnosis and resection. According to the Paris classification, NPTs are distinguished in slightly elevated (0-IIa, less than 2.5 mm), flat (0-IIb) or slightly depressed (0-IIc). NPTs are usually flat or slightly elevated and tend to spread laterally while in case of depressed lesions, cell proliferation growth progresses in depth in the colonic wall, thus leading to an increased risk of submucosal invasion (SMI) even for smaller neoplasms. NPTs may be frequently missed by inexperienced endoscopists, thus a careful training and precise assessment of all suspected mucosal areas should be performed. Chromoendoscopy or, if possible, narrow-band imaging technique should be considered for the estimation of SMI risk of NPTs, and the characterization of pit pattern and vascular pattern may be useful to predict the risk of SMI and, therefore, to guide the therapeutic decision. Lesions suitable to endoscopic resection are those confined to the mucosa (or superficial layer of submucosa in selected cases) whereas deeper invasion makes endoscopic therapy infeasible. Endoscopic mucosal resection (EMR, piecemeal for LSTs > 20 mm, en bloc for smaller neoplasms) remains the first-line therapy for NPTs, whereas endoscopic submucosal dissection in high-volume centers or surgery should be considered for large LSTs for which en bloc resection is mandatory and cannot be achieved by means of EMR. After piecemeal EMR, follow-up colonoscopy should be performed at 3 mo to assess resection completeness. In case of en bloc resection, surveillance colonoscopy should be scheduled at 3 years for adenomatous lesions ≥ 1 cm, or in presence of villous features or high-grade dysplasia patients (regardless of the size), while less intensive surveillance (colonoscopy at 5-10 years) is needed in case of single (or two) NPT < 1 cm presenting tubular features or low-grade dysplasia at histology.

Submucosal injection solution for endoscopic resection in gastrointestinal tract: a traditional and network meta-analysis

Objective. To explore and define the current optimal submucosal injection solution used in ESD and EMR for gastrointestinal tract neoplasms in terms of clinical outcomes and other aspects. Methods. PubMed, Cochrane Library, Embase, and clinical trials register center were searched with terms of “endoscopic resection” and “submucosal injection solution” to identify relevant randomized controlled trials (RCTs). Both direct comparison using traditional meta-analysis method and indirect comparison using network meta-analysis method were performed. Results. A total of 11 RCTs with 1152 patients were included. Meta-analysis showed that, compared with normal saline, other submucosal injection solutions induced a significant increase in terms of en bloc resection rate (I² = 0%, OR = 2.11, 95% CI (1.36, 3.26), and P = 0.008) and complete resection rate (I² = 0%, OR = 2.14, 95% CI (1.41, 3.24), and P = 0.0003); and there was no significant difference in the incidence of total complications (I² = 0%, OR = 0.87, 95% CI (0.59, 1.29), and P = 0.49). Conclusions. Other newly developed submucosal injection solutions significantly increased en bloc resection rate and complete resection rate and decreased bleeding rate and finical cost of endoscopic resection in gastrointestinal tract, while current evidence did not find the difference between them, which need to be explored by further studies.

Successful endoscopic strategies for difficult polypectomy

PURPOSE OF REVIEW

Standard endoscopic polypectomy is a powerful technique to remove most polyps found in the gastrointestinal tract. However, a small percentage of polyps can be classified as difficult, based on size, location, and/or configuration. Traditionally, these difficult polyps were referred for surgical segmental colectomy. Recently, with advancements in endoscopic techniques and accessories, a majority of these difficult polyps are now able to be completely resected using entirely endoscopic techniques.

RECENT FINDINGS

Endoscopic techniques and accessories have been evolving during recent years, including increased dissemination of techniques of endoscopic submucosal dissection to the western hemisphere. In addition to refinement of endoscopic techniques, there has been increased interest in developing improved endoscopic accessories, including novel submucosal injectate with auto-dissecting properties, to improve safety and efficiency of endoscopic resection of difficult polyps.

SUMMARY

This article will review currently available techniques and strategies for successful endoscopic resection for difficult polyps.

Endoscopic resection for gastrointestinal neuroendocrine tumors

Gastrointestinal (GI) and neuroendocrine tumors (NETs) can be treated by mini-invasive endoscopic resection when localized in the superficial layers of the bowel wall and their size is <20 mm. Endoscopic diagnosis of NETs is usually incidental or suspected after clinical, laboratory or imaging findings. Endoscopic mucosal resection is the most commonly used technique for NET removal, endoscopic submucosal dissection is indicated in selected cases, while papillectomy is feasible for ampullary lesions. Histopathologic assessment of the resection margin (circumferential and deep) is important for staging. Incidence of endoscopic mucosal resection-/endoscopic submucosal dissection-related complications for removal of GI NETs are similar to those reported for other GI lesions. Endoscopic follow-up is based on histopathologic characteristics of the resected NETs and its site. NETs >20 mm in size, with penetration of the muscle layer and/or serosa are at high risk for metastases and surgical approach is recommended when feasible.