High-pressure jet injection of viscous solutions for endoscopic submucosal dissection: a study on ex vivo pig stomachs

Endoscopic submucosal dissection: How to be more efficient?

Endoscopic submucosal dissection (ESD) allows an "en bloc" resection with safety margins (R0 resection) regardless of the size of the lesion. However, while R0 brings a real benefit for the patient, it is not considered sufficient by many experts to justify the technical difficulties and the longer procedure time compared to piecemeal mucosectomy. The aims of this review are to provide several technical and strategical tips to help you save time and become comfortable during ESD procedures. ESD is divided into several intertwined phases: injection, incision, access to the submucosae, and submucosal dissection itself. During injection there are some mistakes that should not be made: a superficial injection, or on the contrary, a too deep injection. A good needle and good injection technique are mandatory. Some techniques, such as repeated injection or prolonged lifting solution, can help maintain the lift. After this step, mucosal incision can be made, taking care to have a good margin to allow an R0 resection. Starting the mucosal incision from a small point allows calibration of the depth of the incision and then obtaining a nice incision. Trimming is also very important to widen submucosal access. Then comes the submucosal dissection itself. Strategies such as the tunnel strategy or the pocket creation method can help to facilitate dissection, but more importantly, traction systems have become unavoidable, especially in the stomach and colon. Most common complications are bleeding and perforation, and they usually can be managed endoscopically.

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

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

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.

Sclerotherapy needle injections can expand the subserosal and muscularis propria layers and cause a stable mucosal lift in ESD/EMR patients

Background

A mucosal lift is needed for ESD and EMR. Most lifts are made via sclerotherapy needle injection. The firm push needed to penetrate the mucosa often leaves the needle tip in the deep wall. The needle is next withdrawn and fluid injected until a sharp lift (due to submucosal expansion) begins to form; the needle is then held steady and the injection finished. The initial injection may result in a subtle deep lift that resolves quickly. It was the authors’ belief that only submucosal expansion could lead to a stable mucosal lift. A colonic ESD case in which a polyp was inadvertently resected via needle knife in an expanded subserosal plane led to a questioning of this position. This study’s purpose was to determine if stable deep wall mucosal lifts can be generated via bowel wall injection.

Methods

Transmucosal and intramural injections into bovine large bowel were carried out. Stable lifts and lift cross sections were made and examined grossly and histologically to determine the location of the lift fluid. Clinical ESD videos were also reviewed.

Results

Over 200 intact and cross-sectioned lifts were assessed. Gross inspection revealed two types of lifts (superficial and deep), whereas cross sections and histologic analyses revealed examples of stable expansion of the submucosal, muscularis propria, and subserosal layers post injection. Clinical “deep” lifts were also found. Superficial lifts are more focal and taller, whereas deep wall lifts are broader and less prominent.

Conclusion

Stable deep wall mucosal lifts occur and are likely due to the deep starting point of the needle post insertion. If ESD/EMR are attempted with a deep lift, the chances of failure or perforation are high. Lifts must be carefully scrutinized before starting ESD/EMR. Other means of lift establishment should be evaluated and considered.

Electronic supplementary material

The online version of this article (10.1007/s00464-018-6521-5) contains supplementary material, which is available to authorized users.

Utility and performance characteristics of a novel submucosal injection agent (EleviewTM) for endoscopic mucosal resection and endoscopic submucosal dissection

Background

Submucosal injection of a lifting agent is a critical step in endoscopic mucosal resection (EMR), and endoscopic submucosal dissection (ESD). Literature suggests superiority of other viscous solutions over normal saline (NS), but research to determine the ideal submucosal injection is still ongoing. In this prospective cohort study, we evaluated the utility and performance characteristics of a novel submucosal injection agent (Eleview^TM) for EMR and ESD.

Methods

Twelve consecutive patients referred for EMR/ESD to a tertiary referral center with experienced large polyp expert were prospectively enrolled. Ten patients with large colon polyps (mean age 66.3 years), and one patient each with esophageal and gastric lesions were included. Eleview^TM was injected as submucosal lifting agent, and EMR/ESD performed. Main outcome measurements included the duration of submucosal elevation, volume and number of injections required to maintain cushion, and complications.

Results

Single injection of 3-5 cc of Eleview^TM outlasted the duration of EMR. However, mean duration of cushion achieved during longer procedures (ESD) was 12.5 min, requiring several additional injections. R0 resection was achieved in 10/12 patients. One patient had minor bleeding which was managed intra-operatively.

Conclusions

Eleview^TM was successful in achieving long duration of submucosal elevation, allowing safe and efficient performance of EMR as a single injection, but needed repeated injections during longer ESD procedures. Prospective controlled trials are required to compare its performance to other available viscous submucosal solutions.

Experimental gastric endoscopic submucosal dissection: training in a porcine model

Background

Endoscopic submucosal dissection (ESD) requires special skills and a long procedure time for a quality-controlled procedure. A universal training system remains to be established. Hands-on courses in animal models before advancing to the human colon appear to be essential, especially in Europe. The learning curve is a prerequisite in ESD, in order to improve technical outcomes and decrease the rate of procedural adverse events.

Methods

In the experimental research center of ELPEN Pharmaceuticals, 18 European endoscopists, inexperienced at ESD, performed gastric ESDs in porcine models. The course lasted two days and was conducted under the supervision of experts.

Results

A total of 72 of 76 ESDs were completed en bloc (94.7%). The procedural time and cutting speed differed significantly between the first and second day: 48±4.4 vs. 43±4.8 min (P=0.0045), and 1.38±0.20 vs. 1.63±0.23 cm²/min (P=0.0033), respectively. The complications were not significantly different between the two groups: five (13.88%) vs. four (11%) episodes of bleeding (P>0.05). The perforation rate was similar, at two episodes per day (5.55%). We documented an acceptable rate of en bloc resections and complications.

Conclusion

ESD demands a new level of endoscopic skills in Europe. A formal sequential training program, using porcine models, may benefit countries with a low volume of cases.

Waterjet submucosal dissection of porcine esophagus with the HybridKnife and ERBEJET 2 system: a pilot study

Background and study aims Esophageal endoscopic submucosal dissection (ESD) is technically difficult because of narrow working spaces and ease of perforation due to the lack of serosa. HybridKnife is a recently developed ESD device that is combined with the high pressure waterjet ERBEJET 2 system to lift mucosa. We hypothesized that this waterjet could make submucosal dissection safer and studied this in porcine esophagus. Materials and methods Water pressures of 30 - 70 bar were tested to determine the appropriate pressure for waterjet ESD with HybridKnife (WJ-ESD) in one pig. WJ-ESD safety and completion were compared with those of conventional ESD using DualKnife (C-ESD) as a reference. Each of three virtual esophageal lesions in two pigs were resected alternatively using both methods from the lower to upper esophagus. For WJ-ESD, the submucosa, apart from hard fibrous tissues, was dissected using water pressure alone. Results Using 50 bar of water pressure resulted in the best balance between proper dissection and view-disturbing water backflow. The dissection speeds for the lower, middle, and upper esophagus were 0.2, 0.9, and 0.2 cm²/min in 50 bar WJ-ESD and 1.1, 0.5, and 1.0 cm²/min in C-ESD, respectively. Minor bleeding was frequent in WJ-ESD, but was easily stopped by electrocoagulation with the same needle. No perforation was observed in either procedure. Thermal damage to dissected tissues appeared mild, and the extent of muscle injury was lower for WJ-ESD (4, 6, and 8 %) compared with C-ESD (14, 16, and 7 %). Conclusions WJ-ESD could be completed safely for porcine esophagus with less damage to the muscle layer compared with C-ESD.

A local structured training program with live pigs allows performing ESD along the gastrointestinal tract with results close to those of Japanese experts

BACKGROUND AND AIMS

The high specific skill needed by ESD limit its widespread use in Europe and animal training is recommended in Europe to improve the results of ESD that are far from Japanese at present. We create a local training program using live pigs as models, along with our human cases, to provide continuous exposure to the technique.

METHODS

Between February 2013 and December 2015, two young operators performed 55 pig gastric ESDs in parallel with 62 human cases for large superficial cancerous lesions. The number and training dates of pig cases were adapted to those of the human cases to achieve continuous exposure to ESD cases.

RESULTS

The en bloc, R0, and curative resection rates were 100%, 85.5% (53/62), and 77.5% (48/62), respectively with no recurrence observed during the one year follow up. There was no statistically significant difference in terms of the R0 or curative resection rates among ESDs performed during 2013-2015 (R0: 80% vs. 86.6% vs. 86.4%; Curative: 80% vs. 86.6% vs. 73%).

CONCLUSION

A local structured training program using live pig models was used to train endoscopists for ESD in humans with high safety and efficiency, similar to results published by Japanese experts.

Endoscopic submucosal dissection with the Nestis® jet injector system with a bifunctional catheter: first prospective clinical trial (NCT: 2012-A00272-41)

BACKGROUND

The Enki-2 water jet system (Nestis SAS^®, Lyon, France) with dual injection and dissection capability significantly reduced ESD procedure time and perforation rates in animal studies. The study aim was to evaluate its efficacy and safety in patients with superficial neoplastic lesions.

METHODS

A prospective study including 18 patients with esophageal, gastric and rectal superficial neoplasms treated by ESD using Enki-2 was designed.

RESULTS

Eighteen lesions (6 esophageal, 3 gastric, 9 rectal, mean diameter 43.5 mm) in 17 patients (10 men, mean age 65.9) were included. The mean procedure time was 65.6 min. One patient needed clipping for an incomplete muscle tear during procedure; there were neither delayed bleedings nor perforation. The "en bloc" resection rate was 100 %, the R0 resection rate was 88.9 % (16/18 lesions), and the curative resection rate was 77.8 %. The 3-month disease-free rate was 92.3 % (12/13 patients, 13/14 lesions, 1 patient lost to follow-up). The 12-month disease-free rate was 69.2 % (9/13 patients, 10/14 lesions, 4 patients lost to follow-up).

CONCLUSIONS

ESD with Enki-2 water jet system is effective and safe for superficial neoplastic digestive lesions.

High pressure jet injection of viscous solutions for endoscopic submucosal dissection (ESD): first clinical experience

BACKGROUND

Long lasting elevation is a key factor during endoscopic submucosal dissection (ESD) and can be obtained by water jet injection of saline solution or by viscous macromolecular solutions. In a previous animal study, we assessed the Nestis Enki II system to combine jet injection and viscous solutions. In the present work, we used this combination in humans in different sites of the digestive tract.

METHODS

We retrospectively report all of the consecutive ESD procedures performed with jet injection of viscous solutions in four centers. Information was collected about the lesion, the procedure, the histological result, and the outcomes for the patient.

RESULTS

In total, 45 resections were completed by six operators: five experts and one beginner with only one previous experience in human ESD. Lesions were located in the esophagus (10), the stomach (11), the duodenum (1), the colon (1) and the rectum (22). Average maximal lesion diameter was 4.8 cm (SD 2.4, range 2 - 11 cm), average lesion surface area was 19.8 cm(2) (SD 17.7, range 2.2 - 72 cm(2)), and average duration of procedure was 79.9 min (SD 50.3 min, range 19 - 225 min). ESD could be conducted while the endoscope was retroflexed at its maximum in 26 cases. Four adverse events were observed: two diminutive perforations and two delayed bleeding occurrences treated conservatively. The R0 resection rate was 91.1 %. The catheter was obstructed in six occurrences of bleeding.

CONCLUSION

Endoscopic submucosal dissection using high pressure injection of viscous macromolecular solutions is safe and effective in different parts of the digestive tract. It does not impede working with the endoscope in the maximal retroflexed position.

New isolated bovine colon model dedicated to colonic ESD hands-on training: development and first evaluation

INTRODUCTION

ESD is the reference method to achieve en bloc resections for large digestive lesions. Nevertheless, it is a difficult and risky technique. Animal models exist to teach the initial skills, particularly in Japan, where pigs' stomachs are dedicated models to gastric ESD. In Europe, we have to develop different strategies of teaching with dedicated colon models. A pig colon is a good model but thinner and narrower than a human's. In this present work, we evaluated a bovine colon model to perform rectal ESD in retroflexion.

METHODS

First, we prepared six bowels to precise the preparation protocol. Then, two endoscopists unexperienced in ESD performed 64 procedures on eight models. Learning curves and factors of variation were studied.

RESULTS

A precise protocol to prepare the colon was defined. The two students achieved en bloc resection in 89.1 % of cases with a rate of 6.2 % of perforations. A large heterogeneity appeared between the speed and the success rate depending mainly on the age of the animal bowel. Using calf colons, the failure rates were higher (p = 0.002) and the speed was lower (p < 0.001) than for adult bovine ones. A learning curve appeared with, respectively, 0.49 and 0.59 cm(2)/min throughout the study. No significant difference appeared between measured and calculated specimen areas.

DISCUSSION

Bovine colon is a new model to teach ESD in colorectal conditions. The bovine age is important to homogenize the model. A learning curve existed with a time procedure decreasing throughout the study. Further studies are needed to evaluate the precise learning curve with more students.

CONCLUSION

A bovine colon model is a suitable model to teach colorectal ESD. Nevertheless, an adult bovine colon model is more homogeneous than a calf one.

[Aseptic process validation and stability study of an injectable preparation of fructose (5%)-glycerol (10%) as part of a hospital clinical research program on endoscopic curative treatment for early epithelial neoplastic lesions of the gastrointestinal tract]

INTRODUCTION

As part of a hospital clinical research program on endoscopic curative treatment for early epithelial neoplastic lesions of the gastrointestinal tract, a new hospital sterile and non-pyrogenic preparation of fructose (5%)-glycerol (10%) was realized. Under pharmaceutical legislation, the provision of this hospital preparation involves of aseptic process validation and achieve a stability study.

MATERIALS AND METHODS

After the aseptic process validation with Mediafill Test, the preparation was made under aseptic conditions associated with a sterilizing filtration according to the good practices preparation. Prepared flexible bags (100mL of solution) were stored for one year in a climatic chamber (25±2°C). To assess stability, the physicochemical controls (fructose concentration, glycerol concentration, hydroxy-methyl-5 furfural [5-HMF] concentration, sodium concentration, pH measure, osmolality and sub-visible particles count) and microbiological (bioburden, bacterial endotoxin and sterility) were performed at regular intervals for one year.

RESULTS

Neither significant decrease of fructose concentration, glycerol concentration and sodium concentration nor pH, 5-HMF, osmolality variations out of specifications were observed for one year. The sub-visible particles count, the bacterial endotoxin and sterility were in accordance with the European pharmacopoeia attesting limpidity, apyrogenicity and sterility of this injectable preparation.

DISCUSSION AND CONCLUSION

The hospital preparation was stable over one year at 25±2°C, ensuring safe administration in humans within the framework of this clinical research.