Efficacy of submucosal injection of different solutions inclusive blood components on mucosa elevation for endoscopic resection

Easily Injectable, Organic Solvent-Free Self-Assembled Hydrogel Platform for Endoscope Mediated Gastrointestinal Polypectomy

Endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (ESR) are used to eliminate tiny, flat lesions in the gastrointestinal tract (GIT). A substantial submucosal cushion is required for effective dissection. Commonly used saline and hypertonic dextrose injections disperse quickly and do not offer significant elevation, whereas polymers such as gelatin and alginate are challenging to inject. In this study, a novel amphiphilic polyglycerol stearate-based hydrogel (PGSH) platform is demonstrated which could be administered via an endoscopic catheter to help create a stable submucosal elevation. PGSH is easy to inject across different needle gauges, shear-thinning, and forms a long-lasting submucosal cushion during ESD. This hydrogel can encapsulate hydrophilic drugs such as streptomycin, allowing controlled enzymatic and nonenzymatic release. Ex-vivo experiments on goat's GIT demonstrate that PGSH is smoothly injectable without clogging the catheter's needle, achieving the necessary submucosal elevation. Furthermore, ex-vivo blood studies demonstrate immediate clotting behavior while maintaining hemocompatibility. In-vivo, investigations in mice show that the hydrogel forms a biocompatible cushion of suitable height with a nontoxic organ profile that does not overexpress inflammatory cytokines. ESD studies in the porcine model suggest that PGSH has the potential to significantly improve treatment outcomes in the early endoscopic removal of gastrointestinal polyps.

Removal of GIT lesions and the role of impedance of the injection solution-an innovative approach to known methods

In this work, for the first time, the specific impedances of various injection solutions as well as the surface and tissue impedance after injection of these solutions were analyzed and compared regarding the radio-frequency surgical cutting process. The impedances of 0.9% NaCl, 4% gelatine, 6% hydroxyethyl starch, 10% glycerol/5% fructose, 10% glucose, 5% and 20% albumin, blood, and blood plasma as well as aqua destillata have been tested in vitro. Even if EMR and ESD are routinely used in clinical practice, there is so far no easy, fast, and safe method to remove larger lesions en bloc. We show that the impedance of the injected solution shows to be a crucial factor for safe removal, especially of larger lesions (Ø > 20 mm) and more importantly in accordance with the requirements of oncology and pathology. KEY MESSAGES: Impedance is playing a crucial factor in the radio-frequency (RF)-surgery. With a higher Impedance there will be less current necessary to reach the aimed voltage. Injection solution Aqua destillata and 10% Glucose, show significantly higher Impedances. Higher impedances lead to less surgical related complications. Minor changes in existing method to improve patent safety.

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.

Evaluation of Eleview® Bioadhesive Properties and Cushion-Forming Ability

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

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

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

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.

A feasibility study of a thermally sensitive elastin-like polypeptide for submucosal injection application in endoscopic resection in 3 animal models

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) can successfully resect large lesions en bloc by using a submucosal injection solution, but the cost of currently available submucosal injection solutions is not satisfactory. The authors' aim was to evaluate the feasibility and effectiveness of a thermally sensitive elastin-like polypeptide (ELP) used as submucosal injection solution in ESD.

METHODS

We conducted an ex vivo study to determine the optimal concentration of ELPs in rabbits, an in vivo study to evaluate the effectiveness of mucosal elevation in rats, and a large animal study to confirm the feasibility of preclinical application by using conventional clinical procedure in pigs.

RESULTS

ELP (500 μM) was proved to be the optimal injectable submucosal injection solution and elevated mucosa more efficiently than any control. The same concentration of ELP exhibited an equivalent effectiveness of mucosal elevation, the retention of the elevation, and minimal bleeding with sodium hyaluronate. The ESD procedure time with 500 μM ELP in a preclinical study with pigs was significantly shorter than with any other concentration of ELP and normal saline solution.

CONCLUSIONS

Use of ELP as submucosal injection solution was feasible, with higher and longer-lasting elevation and fewer adverse events.

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.

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

Background

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

Method

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

Results

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

Conclusion

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

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

BACKGROUND

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

OBJECTIVE

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

DESIGN

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

SETTING

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

PATIENTS

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

INTERVENTIONS

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

MAIN OUTCOME MEASUREMENTS

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

RESULTS

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

LIMITATIONS

Absence of randomization.

CONCLUSION

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

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.

Developments in flexible endoscopic surgery: a review

Flexible endoscopy is increasingly developing into a therapeutic instead of a purely diagnostic discipline. Improved visualization makes early lesions easily detectable and allows us to decide ad hoc on the required treatment. Deep enteroscopy allows the exploration of even the small bowel - for long a "white spot" for gastrointestinal endoscopy - and to perform direct treatment. Endoscopic submucosal dissection is a considerable step forward in oncologically correct endoscopic treatment of (early) malignant lesions. Though still technically challenging, it is increasingly facilitated by new manipulation techniques and tools that are being steadily optimized. Closure of wall defects and hemostasis could be improved significantly. Even the anatomy beyond the gastrointestinal wall is being explored by the therapeutic use of endoluminal ultrasound. Endosonographic-guided surgery is not only a suitable fallback solution if conventional endoscopic retrograde cholangiopancreatography fails, but even makes necrosectomy procedures, abscess drainage, and neurolysis feasible for the endoscopist. Newly developed endoscopic approaches aim at formerly distinctive surgical domains like gastroesophageal reflux disease, appendicitis, and cholecystitis. Combined endoscopic/laparoscopic interventional techniques could become the harbingers of natural orifice transluminal endoscopic surgery, whereas pure natural orifice transluminal endoscopic surgery is currently still in its beginnings.

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

BACKGROUND

Long-lasting lifting is a key factor during endoscopic submucosal dissection (ESD) and can be obtained by water-jet injection of saline solution or by injection of viscous macromolecular solutions. Combination of the jet injection and the macromolecular viscous solutions has never been used yet. We assessed the ability of a new water-jet system to inject viscous solutions in direct viewing and in retroflexion. We compared jet injection of saline solution and hyaluronate 0.5 % to perform ESD on ex vivo pig stomachs in order to evaluate the benefits of macromolecular solutions when injected by a jet-injector system.

METHODS

This is a prospective comparative study in pig stomachs. Using the jet injector, four viscous solutions were tested: hydroxyethyl starch, glycerol mix, hyaluronate sodic (0.5 %), and poloxamer mix. Ten ESDs larger than 25 mm (five in direct viewing and five in retroflexion) and one larger than 10 cm were performed with each solution. ESD with hyaluronate jet injection was then compared with ESD with saline jet injection by performing 50 ESDs in each group. A single, minimally-experienced operator conducted all the procedures.

RESULTS

All 145 resections were complete, including all marking points with two perforations. Eleven jet ESDs per solution were conducted without any injection issue. In the second part of the study, when compared with saline, significant benefit of hyaluronate was observed on dissection speed (0.80 vs. 1.08 cm(2)/min, p < 0.001).

CONCLUSION

This is the first report on a jet-injector system allowing injection of macromolecular viscous solutions even with retroflexed endoscope. Jet injection of macromolecular solutions can speed up dissection in comparison with saline, and should now be tested on humans.

Non-exposed endoscopic wall-inversion surgery as a novel partial gastrectomy technique

In gastric full-thickness resection employing both endoscopy and laparoscopy, intraabdominal contamination or even possibly tumor seeding is unavoidable as a result of iatrogenic perforation and the resultant spread of gastric juice. To minimize contamination and resected tissue volume, we developed a new technique without perforation termed non-exposed endoscopic wall-inversion surgery (NEWS), and present here the preliminary results. In a clinical observation cohort study, NEWS was attempted in six patients with gastric SMT to investigate the procedure, mortality, and morbidity. NEWS consists of several steps: marking around a tumor on the mucosal as well as the serosal surface, submucosal injection of sodium hyaluronate with indigo carmine dye, circumferential seromuscular dissection with suture closure under laparoscopy, and circumferential mucosubmucosal incision under gastric endoscopy. The resected specimen is then retrieved perorally. Perforation occurred as a result of misidentification and technical inadequacy in the first three patients. After modification of the devices, the entire procedure was successfully achieved in the latter three. There were no complications in any of our six cases. NEWS allows en bloc full-thickness resection, theoretically avoiding contamination and tumor dissemination into the peritoneal cavity.

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.