Efficacy and safety of 0.6% sodium alginate solution in endoscopic submucosal dissection for esophageal and gastric neoplastic lesion: A randomized controlled study

Easily injectable gelatin-nonanal hydrogel for endoscopic resectioning of gastrointestinal polyps

The use of submucosal injection is crucial for satisfactory submucosal elevation in the early resection of flat polyps originating from the gastrointestinal tract (GIT). Injectable hydrogels derived from natural polypeptides are attractive candidates due to their excellent biocompatibility and easy gelation properties. However, most of the reported hydrogels are not the class of catheter delivery materials due to quick gelation, high inherent viscosity, and injection clogging. This study presents a novel injectable shear-thinning hydrogel platform of small molecules (nonanal) modified gelatin polymer, which offers a promising submucosal injection for effective removal of polyps from GIT. Physicochemical characterizations of hydrogel demonstrate the suitable features as an effective submucosal injection, including shear thinning property, self-assembly, methylene blue dye encapsulation, flow behavior, stability, syringeability (18 G, 21 G, and 24 G needles) and fibrous morphology. Ex vivo investigations of developed submucosal formulation on goat intestines demonstrate the enhanced visibility of cushions and the ability to produce stable, long-lasting cushions of about 8.07 mm up to ∼60 min of submucosal injection. The rapid blood clotting behavior of hydrogel was observed in about 120 s without compromising hemocompatibility with the hemolysis of about 3.77 % only. In vitro biocompatibility of the hydrogel was also verified using the HepG2 and nHDF cells. In vivo study depicts desirable biocompatibility, a non-toxic organ profile, and optimal cushion height in mice models. Studies established the foundation of novel submucosal fluid to improve the therapeutic outcomes of early resection for gastrointestinal polyps.

Temperature-sensitive injectable chitosan-based hydrogel for endoscopic submucosal dissection

Endoscopic submucosal dissection (ESD) is an effective treatment for polyps and early gastrointestinal cancers, but requires a high level of operator skill. Injecting submucosal materials (SIM) helps create a fluid cushion between the mucosal and muscular layers, making the procedure easier and reducing associated risks. However, SIMs commonly used in current clinical practice tend to spread quickly and fail to provide long-lasting submucosal fluid cushions (SFC). Thus, there is a critical need for a material that is easy to inject while also maintaining a durable barrier. We prepared succinylated hydroxybutyl chitosan (HBC-SA) by adding succinic anhydride (SA) to hydroxybutyl chitosan (HBC). The hydrogel had excellent temperature-sensitive properties and was able to be injected via an endoscopic injection needle even after gel formation. In vitro and in vivo studies showed that it has satisfactory biocompatibility. Functional experiments showed that the submucosal lifting properties of this hydrogel were significantly better than that of normal saline (NS) and sodium hyaluronate (SH), two commonly used clinical materials. In addition, the hydrogel possessed excellent hemostatic properties. Based on these results, HBC-SA is a promising candidate for submucosal injection during ESD.

Predictors of stricture after endoscopic submucosal dissection of the esophagus and steroids application

BACKGROUND

Endoscopic submucosal dissection (ESD) is a reliable method to resect early esophageal cancer. Esophageal stricture is one of the major complications after ESD of the esophagus. Steroid prophylaxis for esophageal strictures, particularly local injection of triamcinolone acetonide (TA), is a relatively effective method to prevent esophageal strictures. However, even with steroid prophylaxis, stenosis still occurs in up to 45% of patients. Predicting the risk of stenosis formation after local TA injection would enable additional interventions in risky patients.

AIM

To identify the predictors of esophageal strictures after steroids application.

METHODS

Patients who underwent esophageal ESD and steroid prophylaxis and who were comprehensively assessed for lesion- and ESD-related factors at Southeast University Affiliated Zhongda Hospital between February 2018 and March 2023 were included in the study. The univariate and multivariate regression analyses were conducted to identify the predictors of stricture among patients undergoing steroid prophylaxis.

RESULTS

A total of 120 patients were included in the analysis. In the oral prednisone and oral prednisone combined with local tretinoin injection groups, the stenosis rates were 44/53 (83.0%) and 56/67 (83.6%), respectively. Among them, univariate analysis showed that the lesion circumference (P = 0.01) and submucosal injection solution (P = 0.04) showed significant correlation with the risk of stenosis formation. Logistic regression analyses were then performed using predictors that were significant in the univariate analyses and combined with known predictors from previous reports, such as additional chemoradiotherapy and tumor location. We identified a lesion circumference < 5/6 (OR = 0.19; P = 0.02) and submucosal injection of sodium hyaluronate (OR = 0.15; P = 0.03) as independent predictors of on esophageal stricture formation.

CONCLUSION

Steroid prophylaxis effectively prevents stenosis. Moreover, the lesion circumference and submucosal injection of sodium hyaluronate were independent predictors of esophageal strictures. Additional interventions should be considered in high-risk patients.

Efficacy and safety of MC-003 solution for endoscopic mucosal or submucosal resection: a prospective, multicenter, randomized, triple-blinded, parallel-group, phase III study

BACKGROUND AND AIMS

The safety and efficacy of solutions for submucosal injection are critical for endoscopic resection of gastric adenomas or early gastric cancers. Although several injectable solutions have been introduced for endoscopic resection, they have some limitations. We aimed to compare the efficacy of the new sodium alginate-based solution MC-003 with that of normal saline (NS; 0.9% sodium chloride).

METHODS

In this randomized, triple-blind study, 70 patients were initially enrolled for EMR or endoscopic submucosal dissection (ESD). The main outcomes included the need for additional injections, completion of en bloc resection, and occurrence of adverse events.

RESULTS

Each group ultimately included 34 patients. Complete en bloc resections were achieved in all patients (P = 1.000). The MC-003 group had more peri-neoplasm tissue fibrosis (P = .056) and needed fewer additional injections for lesions >15 mm (P = .037), located in the distal portion of the stomach (P = .007), and during ESD procedures (P = .001). The adverse event rate was comparable in both groups.

CONCLUSIONS

MC-003 outperformed NS in reducing the need for additional injections during en bloc resection, particularly in larger lesions located in the distal portion of the stomach (where most lesions were found) during ESD procedures, without increasing the incidence of serious adverse events. MC-003 is a promising submucosal injectable solution in real-world clinical settings.

Innovative submucosal injection solution for endoscopic resection with phosphorylated pullulan: a preclinical study

BACKGROUND AND AIMS

A submucosal injection solution is used to assist in endoscopic surgery. The high viscosity of current solutions makes them difficult to inject. In the present study, we developed an extremely low-viscosity, easy-to-use submucosal injection solution using phosphorylated pullulan (PPL).

METHODS

The PPL solutions were prepared at different concentrations, and their viscosities were measured. The mucosal elevation capacity was evaluated using excised porcine stomachs. Controls included 0.4% sodium hyaluronate (SH), 0.6% sodium alginate (SA), and saline. To evaluate the practicality, the catheter injectability of 0.7% PPL was measured, and EMR and endoscopic submucosal dissection (ESD) were performed using the stomach and colorectum of live pigs. As controls, 0.4% SH and saline were used.

RESULTS

The PPL solutions were of extremely low viscosity compared to the solutions of 0.4% SH and 0.6% SA. Nevertheless, the mucosal elevation capacity of PPL solutions for up to 0.7% concentration was similar to that of 0.4% SH, and 0.7% PPL was less resistant to catheter infusion than 0.4% SH and 0.6% SA. In live pig experiments with endoscopic mucosal resection and ESD, snaring after submucosal injection of 0.7% PPL was easier than with 0.4% SH, ESD with 0.7% PPL produced less bubble formation than with 0.4% SH, and the procedure time tended to be shorter with 0.7% PPL than with 0.4% SH because of the shorter injection time.

CONCLUSIONS

The PPL solution is an innovative and easy-to-use submucosal injection solution.

Feasibility and safety of 0.6% sodium alginate in endoscopic submucosal dissection for colorectal neoplastic lesion: A pilot study

Objectives

The usefulness of 0.6% sodium alginate (SA) as a submucosal (SM) injection solution for endoscopic SM dissection (ESD) has gained attention over the past few years. However, using ESD for colorectal neoplastic lesions is not explicitly researched as yet. Thus, we conducted this study to determine the feasibility and safety of 0.6% SA solution for colorectal ESD.

Methods

In this single-center, retrospective pilot study, a total of 100 cases treated with ESD using 0.6% SA as a SM injection solution for colorectal neoplasia at our institute were retrospectively reviewed to clarify the clinical feasibility and safety of 0.6% SA. The primary endpoint was to evaluate the complication rate, and the secondary endpoint was to determine the procedure time and the amount of solution used.

Results

Intraoperative perforation was observed in 1 case (1.0%), 2 cases (2.0%) presented with postprocedural hemorrhage, and no lethal adverse events were observed. The median ESD procedure times were 39.5 min (10-150), and the amount of solution used was less than 20 mL in 67 cases (67.0%). En-bloc resection could be achieved in 97 cases (97.0%). Although six cases underwent subsequent surgery due to the deep SM invasion (>1000 μm), there were no cases with nodal involvement, confirmed through histopathological evaluation.

Conclusions

Our findings indicate that 0.6% SA can potentially ensure safe and secure ESD for colorectal neoplasia.

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.

Randomized controlled trial of new hemostatic material "sodium calcium alginate" in a preclinical model

BACKGROUND

The demand for nonbiological hemostatic materials has increased in surgical practice; however, few have sufficient hemostatic efficacy. This study investigated whether optimizing the composition of sodium calcium alginate, which forms a stable gel, improves hemostatic efficacy.

METHODS

The sodium calcium alginate was changed for each composition, including powder size, calcium substitution rate, molecular weight, and mannuronic/guluronic acid ratio. The hemostasis in liver punch-out injury and bleeding was evaluated using swine. For the study, sodium calcium alginate with different compositions was randomly applied to bleeding sites. Previous hemostatic materials, including cellulose and sodium alginate, were used as a control. We investigated hemostasis at 2 and 5 minutes after application.

RESULTS

Each powder size (53-150 μm, 150-250 μm, 53-250 μm) had a similar hemostatic effect. However, the hemostatic rate was significantly higher in sodium calcium alginate than in previous hemostatic materials (P value < .01). A 74.1% calcium substitution rate had the highest hemostasis at 2 and 5 minutes after application (2 minutes: 100%, 5 minutes: 95.2%). Regarding molecular weight, the hemostatic rate was significantly higher in 333,000 than in 50,000 (2 minutes: 95% vs 70%, 5 minutes: 95% vs 70%, P = .038). Moreover, a 1.9 mannuronic/guluronic acid ratio had the highest hemostasis compared with the 0.4 mannuronic/guluronic acid ratio (2 minutes: 58.8% vs 11.8%, 5 minutes: 58.8% vs 0%, P = .033) CONCLUSION: The composition of sodium calcium alginate with a high hemostatic effect was optimized. This new hemostatic material demonstrated potential usefulness for bleeding during surgery.

Novel endoscopic management of gastroenterological anastomosis leakage by injecting gel-forming solutions: an experimental animal study

BACKGROUND

Anastomotic leakage (AL) after gastrointestinal surgery remains a challenging complication that requires surgical or non-surgical treatment. Although various therapeutic endoscopic techniques are available, no definitive interventions exist. We developed a therapeutic endoscopic submucosal injection method using novel gel-forming mixed solutions to close AL and evaluated the elasticity of the developed hydrogel. The safety and efficacy of the injection method were explored in porcine AL models.

METHODS

We developed a novel gel-forming solution, and the formed gel lasted approximately one week within the gastrointestinal wall. An indentation test evaluated the elasticity of the novel hydrogel. After the confirmation of AL on porcine anterior gastric walls, sodium alginate was endoscopically injected into the submucosal layer around the leakage site circularly, followed by a calcium lactate/chitosan-based solution. After that, the outcomes data were collected, and histopathological effectiveness was evaluated.

RESULTS

The increased sodium alginate elasticity with the addition of calcium lactate/chitosan-based solution facilitated long-lasting gel formation. Four pigs with AL underwent this intervention consecutively. Each endoscopic injection was completed in less than 5 min. No significant complications were observed for 3 weeks after the intervention. All AL sites were macroscopically healed. Histopathologic findings at 3 weeks showed that the wall defect was filled with collagen fibers that had grown around the site of the muscle layer tear. No tissue necrosis was observed.

CONCLUSION

This preclinical study demonstrated that the therapeutic injection method for gastroenterological AL using gel-forming solutions could be an alternative endoscopic treatment, especially in patients with severe conditions or comorbidities. The optimal target of this treatment is small size and early AL without poor blood flow or intense hypertrophic scar lesions.

Hybrid and Conventional Endoscopic Submucosal Dissection for Early Gastric Neoplasms: A Multi-Center Randomized Controlled Trial

BACKGROUND & AIMS

Hybrid endoscopic submucosal dissection (H-ESD), which incorporates endoscopic submucosal dissection (ESD) with endoscopic mucosal resection, has been developed to make ESD technically easier. This study aimed to determine if H-ESD is superior to conventional ESD (C-ESD) for small early gastric neoplasms (EGNs).

METHODS

We conducted a multi-center, prospective, open-label, randomized controlled trial to compare the treatment outcomes of H-ESD and C-ESD (Hybrid-G Trial). Patients with differentiated type intramucosal EGN ≤20 mm in diameter and without ulceration were randomly assigned (1:1) to groups that underwent H-ESD or C-ESD. A single multi-functional snare, SOUTEN (ST1850-20, Kaneka, Medix, Tokyo, Japan), was used for H-ESD. The primary outcome was procedure time. Secondary outcomes included mucosal incision time, time and speed of submucosal dissection, curability, and endoscopic procedural adverse events.

RESULTS

A total of 39 and 40 patients underwent H-ESD and C-ESD, respectively. The procedure time of H-ESD was significantly shorter than that of C-ESD (33.16 min vs 62.46 min; H-ESD/C-ESD ratio: 0.53; 95% confidence interval, 0.41-0.69; P < .0001). There was no significant difference in mucosal incision time between the 2 groups; the time and speed of submucosal dissection of H-ESD were significantly shorter than those of C-ESD. No difference was observed between the 2 groups in other outcomes.

CONCLUSIONS

H-ESD has significantly shorter procedure time than C-ESD, with high and comparable curability and safety for both H-ESD and C-ESD. H-ESD can be a good option for the endoscopic treatment of small EGNs. (UMIN Clinical Trials Registry, Numbers: UMIN000041244).

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.

Injectable shear-thinning sodium alginate hydrogels with sustained submucosal lift for endoscopic submucosal dissection

Endoscopic submucosal dissection (ESD) is one of the most effective approaches for the minimally invasive treatment of early gastrointestinal cancers. Submucosal injections help safely and successfully remove lesions during ESD by elevating the mucosa and separating the submucosal muscle layer. Herein, we report dynamic injectable sodium alginate hydrogels (ISAHs) with shear-thinning for ESD surgery, which were easily fabricated by the sulfhydryl group of GSH-modified sodium alginate (SA-GSH) reacting with the aldehyde group of oxidized sodium alginate (OSA) at room temperature. ISAHs have advantageous self-healing abilities and antioxidant activity. Additionally, according to an in vitro test on porcine colorectal submucosal lifting, the submucosal elevation heights created by ISAHs were 13 % -18 % greater than those created by commercial ESD solutions (0.4 w/v% sodium hyaluronate). These properties and biocompatibility were confirmed in vitro and in vivo experiments. ISAHs will hopefully become a novel submucosal injectable hydrogel to assist ESD surgery.

Preparation and ex vivo investigation of an injectable microparticulate formulation for gastrointestinal mucosa polyp resection

Endoscopic submucosal dissection (ESD) and endoscopic submucosal resection (EMR) are non-invasive endoscopic techniques. They allow an early excised gastrointestinal (GI) mucosal precancerous lessions. For their application is necessary use of a submucosal injection that lift area to excise. The main objective of this study was the preparation of microparticulate-based fluid for injection in the GI submucosa. Alginate microparticles (MPs) were developed by the solvent displacement technique and characterized by particle size, surface electrical properties, swelling, degradation, rheology, adhesion and leakage, syringeablity and stability. Furthermore, their potential to form a submucosal cushion was assayed in porcine stomach mucosa and porcine colon mucosa. Results showed MPs sizes below 160 μm, negative surface charge around -50 mV at pH=6, high rates of swelling and good adhesion. The microparticulate-based fluid exhibited pseudoplastic behavior following the Ostwald-de Waele rheological model. A brief force is sufficient for its injection through a syringe. Finally, formulations were able to provide a submucosa elevation of 1.70 cm for more than 90 min and 120 min in the porcine stomach and colon, respectively.

Comparisons of outcomes between ProKnife injection endoscopic submucosal dissection and conventional endoscopic submucosal dissection for large gastric lesions in ex vivo porcine model study: A randomized controlled trial

Objective

To compare treatment outcomes between injection endoscopic submucosal dissection using ProKnife (P‐ESD) and conventional ESD (C‐ESD) for gastric lesions.

Methods

In this randomized controlled trial, we compared treatment outcomes of P‐ESD and C‐ESD for simulated gastric lesions ≥3 cm in resected porcine stomachs. Predictive factors associated with ESD difficulties were investigated using logistic regression analysis.

Results

Seventy lesions were screened; however, two lesions were excluded. A total of 12 endoscopists performed 68 ESDs: 34 P‐ESDs and 34 C‐ESDs. The ESD procedure time of P‐ESD (36.3 [28.4–46.8] min) was significantly shorter than that of C‐ESD (46 [36.4–64.6] min; p = 0.0014). The technical success rates did not differ between the P‐ESD and C‐ESD groups (en bloc resection rate, 100% in both groups; complete resection rate, 94.1% and 85.3%, respectively; p = 0.23). The number of injections during P‐ESD (7.5 [6–10] times) was significantly higher than during C‐ESD (4 [3–5] times; p < 0.001), but the total volume of injected solution during P‐ESD (20 [16–26.3] ml) was significantly smaller than during C‐ESD (27.5 [20–31.5] ml; p = 0.0019). In multivariate analysis, less ESD experience (odds ratio [OR], 3.9) and selection of C‐ESD as the ESD method (OR, 3.8) were independent predictive factors associated with ESD difficulties.

Conclusions

Compared with C‐ESD, P‐ESD had a shorter procedure time but also allowed for notable technical success and safety.

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.

Efficacy of Sodium Carboxymethylcellulose Compared to Sodium Hyaluronate as Submucosal Injectant for Gastric Endoscopic Submucosal Dissection: A Randomized Controlled Trial

INTRODUCTION

Sodium hyaluronate (SH) is a useful submucosal injectant for gastric endoscopic submucosal dissection (ESD). On the other hand, sodium carboxymethylcellulose (SCMC), which has high viscosity, has also been applied clinically. We evaluated the efficacy of SCMC compared to that of SH in gastric ESD.

METHODS

A prospective randomized controlled trial was conducted to assess the efficacy of 1.0% SCMC as the injectant (SCMC group) compared to 0.4% SH (SH group) for ESD of gastric neoplasms. The primary end point was the procedure time of ESD. Secondary end points were treatment outcomes such as en bloc and R0 resection rates, number of hemostases, amount of injectant, ease of treatment (visual analog scale, 1-10 points), adverse events, and rate of ulcer healing 8 weeks after ESD.

RESULTS

A total of 60 patients were enrolled between October 2014 and October 2018, and 30 patients were allocated in each group. The procedure time (mean ± SD, minutes) was not significantly different between the SCMC (74.7 ± 54.5) and SH groups (67.1 ± 41.4) (p = 0.547). Furthermore, there were no differences between the 2 groups in terms of en bloc and R0 resection rates, number of hemostases, amount of injectant, ease of treatment, and rate of ulcer healing. No serious adverse events were observed in either group.

CONCLUSION

SCMC was comparable to SH in terms of procedure time, treatment outcome, and ease and safety of treatment in gastric ESD. Further studies are needed to demonstrate the differences between the 2 injectants.

Off-label use of 0.4 % sodium hyaluronate teardrops: a safe and effective solution for submucosal injection in gastric endoscopic submucosal dissection

Background and study aims  Submucosal (SM) injection is a critical step in endoscopic submucosal dissection (ESD). In Japan, use of viscous solutions such as sodium hyaluronate are recommended; the commercially product available is MucoUp (Seikagaku Co. and Boston Scientific Japan Co., Japan). Nevertheless, MucoUp is expensive and unavailable in many Western countries. For the past 8 years, we have been using low-cost sterile teardrops solution composed of 0.4 % sodium hyaluronate (Adaptis Fresh, Legrand Laboratory, Brazil). This solution is readily available in drugstores with a cost of approximately US$ 10.00 for each 10-cc bottle. The aim of this study was to present the clinical outcome with off-label sodium hyaluronate use for SM injection in gastric ESD. Patients and methods  A single-center retrospective study of collected data investigating consecutive patients that underwent gastric ESD between 2012 and 2019. ESD was performed using 0.4 % sodium hyaluronate teardrop for SM injection and Flush Knife BT 2.5 (Fujifilm Co., Japan). The following data were analyzed: clinical-pathological features, en-bloc, R0 and curative resection rate, procedure duration, adverse events, and clinical outcome. Results  ESD was performed with sodium hyaluronate for submucosal injection in 78 patients. The en-bloc resection rate and R0 resection rate were 96.1 % and 92.3 %, respectively. The curative resection rate for epithelial lesions was 83.8 %. Adverse events occurred in 5 cases (6.3 %): delayed bleeding (3.8 %, 3 cases) and perforation (2.5 %, 2 cases); all managed successfully by clipping and thermal coagulation. The mean volume of sodium hyaluronate solution used per patient was 10 cc (SD: ± 8 cc). During follow-up (mean: 17 months; SD: ± 14.5 months), two patients developed metachronous lesions (2.5 %). Conclusions  Off-label use of teardrops with 0.4 % sodium hyaluronate for submucosal injection was demonstrated to be safe and able to provide an effective submucosal cushion that facilitates SM dissection in gastric ESD procedures.

Viscosity and degradation controlled injectable hydrogel for esophageal endoscopic submucosal dissection

Endoscopic submucosal dissection (ESD) is a common procedure to treat early and precancerous gastrointestinal lesions. Via submucosal injection, a liquid cushion is created to lift and separate the lesion and malignant part from the muscular layer where the formed indispensable space is convenient for endoscopic incision. Saline is a most common submucosal injection liquid, but the formed liquid pad lasts only a short time, and thus repeated injections increase the potential risk of adverse events. Hydrogels with high osmotic pressure and high viscosity are used as an alternate; however, with some drawbacks such as tissue damage, excessive injection resistance, and high cost. Here, we reported a nature derived hydrogel of gelatin-oxidized alginate (G-OALG). Based on the rheological analysis and compare to commercial endoscopic mucosal resection (EMR) solution (0.25% hyaluronic acid, HA), a designed G-OALG hydrogel of desired concentration and composition showed higher performances in controllable gelation and injectability, higher viscosity and more stable structures. The G-OALG gel also showed lower propulsion resistance than 0.25% HA in the injection force assessment under standard endoscopic instruments, which eased the surgical operation. In addition, the G-OALG hydrogel showed good in vivo degradability biocompatibility. By comparing the results acquired via ESD to normal saline, the G-OALG shows great histocompatibility and excellent endoscopic injectability, and enables create a longer-lasting submucosal cushion. All the features have been confirmed in the living both pig and rat models. The G-OALG could be a promising submucosal injection agent for esophageal ESD.

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Injectable gel with controlled viscosity.

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Injectable gel with controlled degradation.

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Making esophageal submucosal liquid cushion.

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Potential treatment for early esophageal cancer.

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Big animal in-situ imaging.

Management following endoscopic resection in elderly patients with early-stage upper gastrointestinal neoplasia

With the ongoing increase in the aging population in Japan, the number of elderly patients among the total population with upper gastrointestinal (GI) neoplasia has also been increasing. As elderly patients present unique age-related variations in their physical condition, the therapeutic approach for upper GI neoplasia should be differentiated between elderly and nonelderly patients. According to the existing guidelines, additional treatment is the standard therapy in patients who undergo endoscopic resection (ER) with a possible risk of lymph node metastasis (LNM) for upper GI neoplasia. However, due to the relatively low rate of LNM, applying additional treatment in all elderly patients may be excessive. Although additional treatment has the advantage of reducing cancer-specific mortality, its disadvantages include deteriorated quality of life, complications, and mortality in surgery. In patients with early gastric cancer, we propose treatment decisions be made using a risk-scoring system for LNM and upon considering the physical condition of the patient after ER with curability C-2. In those with superficial esophageal squamous cell carcinoma with a possible risk of LNM after ER, selective chemoradiotherapy may be a less-invasive treatment option, although the present standard treatment is esophagectomy. When considering the treatment decision, achieving a "cure" of the tumor has been regarded as critical. However, as the main cause of mortality in elderly patients with ER for upper GI neoplasia is noncancer-related death, both achieving a "cure" and also a good level of "care" is important in the management of elderly patients.

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.

Endoscopic submucosal dissection: an update on tools and accessories

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