Submucosal tunneling endoscopic resection: An effective and safe therapy for upper gastrointestinal submucosal tumors originating from the muscularis propria layer

Advances in Third Space Endoscopy

This article offers a detailed overview of recent advancements in third space endoscopy (TSE), highlighting key procedures and their clinical applications and outcomes. Clinical TSE started as a treatment for achalasia and was named peroral endoscopic myotomy (POEM). Outcome data and comparative data of POEM with other treatments were detailed and discussed. This article also explores the indications and outcomes of other TSE procedures, such as G-POEM, Z-POEM, D-POEM, per-rectal endoscopic myotomy, and STER/POET. This article serves as a valuable resource for endoscopists looking to enhance their understanding and stay updated on these advanced TSE procedures.

Tips and Thought Processes to Overcome Difficult Situations in Third Space Endoscopy

PURPOSE OF REVIEW

Third space endoscopy (TSE) offers diverse treatment options for a variety of conditions of the gastrointestinal tract and motility disorders. Accuracy and precise dissection have helped treat complex conventional surgeries with TSE. Despite over a decade of its presence, difficult situations are routinely encountered.

RECENT FINDINGS

The first challenging situation is decision-making (before the procedure), the second is tackling procedure-induced pulmonary / insufflation-related adverse events and intra-operative complications (during the procedure), and the third is post-operative complications and morbidity (post-procedure). The performance of TSE procedures is not without risk. Patients should receive enough time to weigh their options, considering that attitudes toward risk impact decision-making. Continuous basic patient monitoring and the micro-movements of endoscopic and electrosurgical equipment is crucial to avoid accidental injury. Anaesthetists should be mindful of anticipated complications and closely monitor, diagnose, and treat them. Demanding situations need careful consideration, problem-solving, or persistence to overcome challenges. This brief review provides inputs on preventing and tackling difficult situations in TSE.

Prevention, detection and management of adverse events of third-space endoscopy

Third space endoscopy (TSE) or sub-mucosal endoscopy using a mucosal flap valve (SEMF) enables the endoscopist to operate in the deeper layers of the gastrointestinal tract or gain access to the mediastinal/peritoneal cavity for natural orifice transoral endoscopic surgery (NOTES). TSE procedures are essentially endoscopic surgical procedures with a variable learning curve. Adverse events (AEs) during TSE are specific and follow a certain pattern across the spectrum of TSE procedures. These can be broadly categorized according to either type of AE, time of presentation relative to the procedure or according to degree of severity. Three major categories of AEs encountered during TSE include insufflation related AEs, mucosal injuries (MIs) and bleeding. Other relevant AEs include infectious complications, aspiration pneumonia, post-procedural chest/abdominal pain, atelectasis, cardiac arrhythmias, pleural effusion and pulmonary embolism. Reported incidence of AEs during TSE procedures varies according to the type and complexity of procedure. Acquaintance regarding potential risk factors, technical tips and precautions, alarm signs for early recognition, assessment of degree of severity, morphological characterization of AEs and finally, expeditious selection of appropriate management strategy are crucial and imperative for successful clinical outcomes. The current review discusses the current evidence and practical guidelines for prevention, early detection and management of TSE-related AEs.

Complications related to third space endoscopic procedures

Third space endoscopy (TSE) encompasses a breadth of procedures for the treatment of a variety of GI disorders. The widespread use of per-oral endoscopic myotomy (POEM) and its diversification to include extended indications and at locations other than the oesophagus has provided an insight into the potential complications encountered. The most common adverse events associated with POEM, the epitome of TSE procedures, include insufflation related injuries, bleeding, failure of mucosal barrier, infections, pain, blown out myotomy and gastroesophageal reflux disease. The purpose of this review is to highlight the pitfalls and to identify the risk factors that may lead to adverse events, and to recommend appropriate salvage interventions in the scope of the current evidence.

Comparable long‑term survival outcomes of endoscopic treatment versus surgical treatment for gastrointestinal stromal tumors with a diameter of 5-10 cm

Currently, endoscopic treatment for small gastrointestinal stromal tumors (GIST) has been widely accepted. However, for tumors larger than 5 cm, endoscopic treatment has not been recognized by national guidelines as the standard therapy due to concerns about safety and adverse tumor outcomes. Therefore, this study compares the long-term survival outcomes of endoscopic treatment and surgical treatment for GIST in the range of 5-10 cm. We selected patients with GIST from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2015. Kaplan-Meier analysis and the log-rank test were employed to compare the long-term survival outcomes between endoscopic treatment and surgical treatment. A multivariate Cox proportional hazards model was used for analysis to identify risk factors influencing patient prognosis. To balance baseline data, we performed 1:1 propensity score matching (PSM). A total of 1223 GIST patients were included, with 144 patients (11.8%) received endoscopic treatment and 1079 patients (88.2%) received surgical treatment. Before PSM, there was no significant difference in the long-term survival rates between the two groups [5-year OS (86.5% vs. 83.5%, P = 0.42), 10-year OS (70.4% vs. 66.7%, P = 0.42)]. After adjusting for covariates, we found that the overall survival (HR = 1.26, 95% CI 0.89-1.77, P = 0.19) and cancer-specific survival (HR = 1.69, 95% CI 0.99-2.89, P = 0.053) risks were comparable between the endoscopic treatment group and the surgical treatment group. In the analysis after PSM, there was no significant difference between the endoscopic treatment group and the surgical treatment group. Our study found that for GIST patients with tumor sizes between 5 and 10 cm, the long-term OS and CSS outcomes were similar between the endoscopic treatment group and the surgical treatment group.

A Large Esophageal Leiomyoma: Thoraco-Laparoscopic Enucleation or Esophagectomy and Reconstruction?

BACKGROUND Esophageal leiomyoma is a rare condition, with an estimated incidence rate of 0.4% of all esophageal neoplasms. These tumors are typically small, rarely more than 5 cm. The treatment depends on symptoms and the size and location of the tumor, with enucleation as the standard treatment of esophageal leiomyomas. Esophagectomy is performed only in very few cases, such as when the tumor is too large, there are multiple leiomyomas, there is a horseshoe shape or circumference, or the tumor is inextricably adhering to the esophageal mucosa. In such complex cases, it is often difficult to perform enucleation. However, with the risks of esophagectomy and intra-thoracic anastomosis, namely reflux, stenosis, leakage, abscess, and infection, attempting to perform enucleation for these cases should still be considered. CASE REPORT We reported a case of a large, multi-lobed, circumferential esophageal thoracoabdominal leiomyoma with successfully performed enucleation and esophageal preservation. A Dor fundoplication and Witzel jejunostomy tube were also performed. Follow-up 3 months postoperatively showed no appearance of reflux or dysphagia. The postoperative esophagogram visualized no obstruction or leakage. Histopathological results gave us concrete evidence of a leiomyoma: elongated cells with eosinophilic cytoplasm and rhomboid nuclei with uniform size. CONCLUSIONS The thoraco-laparoscopic enucleation approach is the method that should be considered first in the treatment of large, multi-lobed, circumferential esophageal leiomyomas, before contemplating esophagectomy and reconstruction.

Electrosurgical unit in GI endoscopy: the proper settings for practice

INTRODUCTION

Electrosurgical unit (ESU) is integral to the endoscopy unit. The proper knowledge of the Mode with setting is essential for good therapeutic outcomes and the safety of the patients.

AREAS COVERED

ESU generates high-frequency electric current, which could perform cutting and coagulation for various therapeutic interventions. We review the proper settings for common endoscopic interventions like hemostasis, polypectomy, sphincterotomy, and advanced procedures like endoscopic ultrasound-guided cysto-gastrostomy, bile duct drainage, and endoscopic Ampullectomy. We review the various waveforms of ESU in practice in endoscopy, including special conditions like patients with pacemakers.

EXPERT OPINION

Knowledge of the waveforms' duty cycle and crest factor is necessary. A high-duty cycle and lower crest factor lead to a good cutting effect on the tissue. Endocut is the most commonly used Mode in ESU in endoscopic practices like sphincterotomy and polypectomy. Endocut I mode (effect 1-2, duration 3, interval 3) is used for endoscopic sphincterotomy, while Forced Coag mode (Effect 2, 60 W) controls post-sphincterotomy bleeding. Endocut Q mode (Effect 2-3, duration 1, interval 3) is used for cutting the polyp, while Forced Coag mode (Effect 2, 60 W) is used before cutting for pre-coagulation of the stalk.

Peroral esophageal myotomy for esophageal motility disorders

The concept of third space endoscopy first described in 2007, was adapted and performed in humans in 2010 by Inoue et al. in a group of patients with esophageal achalasia (EA). Since then, esophageal endoscopic myotomy (E-POEM), has been performed in more than 10,000 patients worldwide up to now. Safety and efficacy have been confirmed at early, mid and long-term evaluations, in different gastrointestinal diseases including achalasia, refractory gastroparesis, and other esophageal motility disorders (EMD). Nowadays, this treatment has shown to be not only an excellent option, but also with its excellent outcomes, the first option in certain clinical scenarios such as type III achalasia. Thus, the minimal invasive nature of POEM gives us multiple advantages compared with the classical treatments that includes pneumatic dilation (PD) and laparoscopic Heller myotomy (LHM), including not only clinical aspects but also economical. High resolution manometry (HRM) has substantially redefined the actual approach of esophageal motility disorders with the major changes in instrumental use, diagnostic algorithms, and therapeutics. The previous Chicago's classification V 3.0 clearly improved our knowledge about pathophysiology of spastic esophageal motor disorders, however, with its recent update (Chicago V 4.0), multiple changes in diagnosis and treatment are expected. In the present article, we aimed to review and analyze the most important aspects about the results of E-POEM in the management of EMD according to the view of the new Chicago's classification V 4.0.

Submucosal Tunneling Techniques for Tumor Resection

The concept of third space endoscopy is based on the principle that the deeper layers of the gastrointestinal tract can be accessed by tunneling in the submucosal space and maintaining the integrity of the overlying mucosa. The mucosal flap safety valve enabled endoscopists to use submucosal space securely. The era of third space endoscopy started with peroral endoscopic myotomy for treatment of achalasia and has expanded to treat various other gastrointestinal disorders, such as mucosal lesions, submucosal tumors, extraluminal tumors, and refractory gastroparesis, Zenker diverticulum, and restoration of the completely obstructed esophageal lumen. Third space endoscopy rapidly emerged as a minimally invasive alternative to conventional surgery. Many studies discovered that this technique is safe and effective with excellent outcomes. Our review focused on the indications, techniques, clinical management, and adverse events of submucosal tunneling techniques for tumor resection.

Updates in the Field of Submucosal Endoscopy

Submucosal endoscopy (third-space endoscopy) can be defined as an endoscopic procedure performed in the submucosal space. This procedure is novel and has been utilized for delivery to the submucosal space in a variety of gastrointestinal diseases, such as a tumor, achalasia, gastroparesis, and subepithelial tumors. The main submucosal endoscopy includes peroral endoscopic myotomy, gastric peroral endoscopic myotomy, Zenker peroral endoscopic myotomy, submucosal tunneling for endoscopic resection, and endoscopic submucosal tunnel dissection. Submucosal endoscopy has been used as a viable alternative to surgical techniques because it is minimally invasive in the treatment and diagnosis of gastrointestinal diseases and disorders. However, there is limited evidence to prove this. This article reviews the current applications and evidence regarding submucosal endoscopy while exploring the possible future clinical applications in this field. As our understanding of these procedures improves, the future of submucosal endoscopy could be promising in the fields of diagnostic and therapeutic endoscopy.

Risk stratification in patients with upper gastrointestinal submucosal tumors undergoing submucosal tunnel endoscopic resection

Background

A substantial heterogeneity exists in patients with upper gastrointestinal submucosal tumors (SMTs). This study aimed to identify predictors of long procedure time (≥60 min), occurrence of procedure-related complications, and long hospital stay (≥6 days) in patients with SMTs undergoing submucosal tunnel endoscopic resection (STER) and stratify risk based on the predictors.

Methods

Sixty-six consecutive patients with upper gastrointestinal SMTs undergoing STER between January 2013 and December 2018 were retrospectively included. Binary logistic regression models were developed to identify predictors of outcomes. Receiver operating characteristic (ROC) curves were constructed to evaluate the discrimination of tumor size.

Results

Complete resection and en bloc resection of tumor were achieved in 66 (100%) and 64 patients (97%), respectively. Twenty-seven patients (41%) had a long procedure time, 10 (15%) developed STER-related complications, and 17 (26%) had a long hospital stay. On multivariable analysis, tumor size was an independent predictor of long procedure time (OR 1.37, 95% CI 1.13-1.67; p = 0.001), occurrence of complications (OR 1.06, 95% CI 1.01-1.10; p = 0.012), and long hospital stay (OR 1.05, 95% CI 1.01-1.09; p = 0.035). ROC curves identified a tumor of size 25 mm as the best cutoff; those who had a tumor above this value had a 76-fold risk of long procedure time, 8.56-fold risk of occurrence of complications, and 6.35-fold risk of long hospital stay.

Conclusion

Patients with a tumor size ≥25 mm had longer procedure time, higher risk of STER-related complications, and longer hospital stay; therefore, they should be classified as a high-risk group.

Efficacy and Safety Analysis of Submucosal Tunnel Endoscopic Resection for Submucosal Masses in Esophageal Muscularis Propria

Objective

To analyze the efficacy and safety of submucosal tunnel endoscopic resection (STER) for the treatment of submucosal masses in esophageal muscularis propria.

Method

A total of 272 patients with submucosal masses in esophageal muscularis propria diagnosed and treated in our hospital from February 2019 to January 2022 were randomly selected for the study and then were randomly divided into the STER group (n = 136) and the endoscopic mucosal dissection (ESD) group (n = 136) according to the random number table method. Patients in the STER and ESD groups were treated with STER and ESD, respectively. The clinical data of patients from the two groups were collected and compared. The clinical effects and the changes of surgery-related indexes of patients after ESD and STER treatment were observed. The safety of ESD and STER was compared. The factors influencing the efficacy of STER treatment for submucosal masses in esophageal muscularis propria were analyzed.

Result

There were significant differences between the STER group and the ESD group in terms of tumor size, lesion level, adhesion and surgical approaches (P < 0.05). The effective rates of ESD treatment and STER treatment were 98.53% and 88.97%, respectively. Meanwhile, the effective rates of STER treatment were significantly higher than those in the control group (P < 0.05). In addition, the patients in the STER group had longer operation time, less blood loss, and shorter hospital stay compared with those in the ESD group (P < 0.05). Adverse reactions occurred during ESD treatment and STER treatment included delayed bleeding, adhesion, perforation, and pleural effusion with the total incidence of adverse reactions of 4.41% and 13.97%, respectively. The adverse reactions in STER group were prominently less than these in the ESD group (P < 0.05). Logistic multivariate regression analysis showed that independent risk factors, including tumor size, lesion level, adhesion, and surgical approaches, affected the efficacy of STER in the treatment of submucosal masses in esophageal muscularis propria (P < 0.05).

Conclusion

STER is an effective method for the treatment of submucosal masses in esophageal muscularis propria, which can exhibit a good effect with faster postoperative recovery and higher safety, thereby being worthy of clinical application and promotion. Tumor size, lesion level, adhesion, and surgical approaches are all related factors affecting the effect of STER treatment.

A scoring system to support surgical decision-making for cardial submucosal tumors

Background and study aims  Submucosal tunneling endoscopic resection (STER) and non-tunneling techniques are two alternative options for the treatment of cardial submucosal tumors (SMTs). We aimed to establish a regression model and develop a simple scoring system (Zhongshan Tunnel Score) to help clinicians make surgical decisions for cardial submucosal tumors. Patients and methods  A total of 246 patients who suffered cardial SMTs and received endoscopic resection were included in this study. All of them were randomized into either the training cohort (n = 147) or the internal validation cohort (n = 99). Then, the scoring system was proposed based on multivariate logistic regression analysis in the training cohort and assessed in the validation cohort. Results  Of 246 patients, 97 were treated with STER and the others with non-tunneling endoscopic resection. In the training stage, four factors were weighted with points based on the β coefficient from the regression model, including irregular morphology (-2 points), ulcer (2 points), the direction of the gastroscope (-2 points for forward direction and 1 point for reverse direction), and originating from the muscularis propria (-2 points). The patients were categorized into low-score (< -4), medium-score (-4 to -3) and high-score (> -3) groups, and those with low scores were more likely to be treated with STER. Our score model performed satisfying discriminatory power in internal validation (Area under the receiver-operator characteristic curve, 0.829; 95 % confidence interval, 0.694-0.964) and goodness-of-fit in the Hosmer-Lemeshow test ( P  = .4721). Conclusions  This scoring system could provide clinicians the references for making decisions about the treatment of cardial submucosal tumors.

Modified submucosal tunneling endoscopic resection for postcricoid esophageal subepithelial tumor

Video 1Technique of submucosal tunneling and endoscopic resection for a postcricoid subepithelial esophageal tumor. After surface marking and submucosal elevation, the mucosa was incised. The subepithelial tumor was dissected from the mucosal aspect and enucleated from the muscle layer. En bloc resection was achieved with an intact capsule. The mucosal incision was closed with endoclips.

rh-ES and Chemotherapy in Advanced Gastrointestinal Cancer in China: A Meta-analysis

BACKGROUND

The purpose of this study was to evaluate the efficacy and safety of recombinant human endostatin (rh-ES) combined with chemotherapy in advanced gastrointestinal tumors in China.

METHODS

A literature search was performed in PubMed, Medline, Springer, Elsevier Science Direct, Weipu, Wanfang, and China National Knowledge Infrastructure (CNKI), with the last report through September 2019. The included research was scored using a modified Jadad scale, and a meta-analysis was performed using RevMan 5.3 software.

RESULTS

Twenty articles including 905 participants (experimental group [rh-ES combined with chemotherapy] 459; control group [chemotherapy alone] 446) were considered. The total effective rate for the experimental group in advanced gastrointestinal tumors was higher than that of the control group (P<0.05). No significant difference in adverse reactions was seen between the two groups (P>0.05).

CONCLUSIONS

The short-term efficacy of rh-ES combined with chemotherapy for advanced gastrointestinal tumors was better, with fewer adverse reactions.

Endoscopic resection of esophageal and gastric submucosal tumors from the muscularis propria layer: submucosal tunneling endoscopic resection versus endoscopic submucosal excavation: A systematic review and meta-analysis

BACKGROUND

Submucosal tunneling endoscopic resection (STER) and endoscopic submucosal excavation (ESE) are less-invasive therapeutic alternatives to surgical resection for the removal of esophageal or gastric submucosal tumors (SMTs). This study aimed to comparing STER versus ESE for the resection of esophageal and gastric SMTs from the muscularis propria.

METHODS

This systematic review and meta-analysis was reported in accordance with PRISMA guidelines through December 2020. Pooled outcome measures included complete resection, en bloc resection, bleeding, perforation, adverse events, recurrence, procedure duration, and length of hospital stay. Risk ratio (RR) and mean difference (MD) was calculated as well as Peto time-to-event analyses to determine recurrence rate.

RESULTS

Five retrospective cohort studies (n = 269 STER versus n = 319 ESE) were included. There was no difference in rates of complete resection [RR: 1.01 (95% CI 0.94, 1.07)], en bloc resection [RR: 0.95 (95% CI 0.84, 1.08)], recurrence [OR: 1.18 (95% CI 0.33, 4.16)], and total adverse events [RR: 1.33 (95% CI 0.78, 2.27)]. Specific adverse events including rates of perforation [RR: 0.57 (95% CI 0.12, 2.74)] and bleeding [RR: 1.21 (95% CI 0.30, 4.88)] were not different between STER and ESE. There was a statistical difference when evaluating procedure time, with the STER group presenting significantly larger values [MD: 24.62 min (95% CI 20.04, 29.20)].

CONCLUSION

STER and ESE were associated with similar efficacy and safety; however, ESE was associated with a significantly decreased time to complete the procedure.

Recent advances in third space or intramural endoscopy

Third space endoscopy or intramural endoscopy is based on the principle that the deeper layers of the gastrointestinal tract can be accessed by tunneling in the submucosal space and maintaining the integrity of the overlying mucosa. The era of third space endoscopy started with peroral endoscopic myotomy (POEM) for treatment of achalasia and has expanded to treat various other gastrointestinal disorders. The technique is also currently used for treatment of refractory gastroparesis, Zenker’s diverticulum (ZD), resection of subepithelial tumors and early cancers of the gastrointestinal tract and Hirschsprung’s disease (HD). These procedures are rapidly emerging as minimally invasive alternatives to conventional surgery. They are safe and effective with excellent outcomes. This review focuses on the evolution and current applications of third space endoscopy in various gastrointestinal disorders. Key points: (1) Third space or intramural endoscopy initially started with the POEM procedure for treatment of achalasia; (2) Advancements in procedural techniques have expanded its application to treat other gastrointestinal disorders such as refractory gastroparesis, ZD, HD, resection of subepithelial tumors and early gastrointestinal cancers; (3) These procedures are highly effective with excellent outcomes and low complication rates; and (4) Third space endoscopic procedures are rapidly emerging as minimally invasive alternatives to conventional surgery.

[Endoscopic diagnosis, treatment, and follow-up of polyps of the upper gastrointestinal tract]

Polyps occur significantly less frequently in the upper gastrointestinal tract compared to the lower gastrointestinal tract. They are usually incidental findings at esophagogastroduodenoscopy. A distinction is made between epithelial lesions and subepithelial tumors. Endoscopic screening is not recommended in Germany (exception: hereditary risk groups). Polyps are sometimes symptomatic, generally in the case of advanced tumor size. In this case, or in the case of potential for malignant transformation, resection is necessary and can usually be performed endoscopically. Surgical resections are rarely necessary. Epithelial lesions are removed by means of endoscopic mucosal resection (EMR). For subepithelial tumors, advanced procedures such as endoscopic submucosal dissection (ESD), submucosal tunneling endoscopic resection (STER), or endoscopic full-thickness resection are available. These procedures should primarily be performed at centers with appropriate expertise. Endoscopic follow-up is primarily determined by the tumor entity and the resection status.

Submucosal Tunnel Endoscopic Resection of Gastric Lesion Before Obesity Surgery: a Case Series

BACKGROUND

Submucosal tumors (SMTs) of the gastrointestinal tract are a rare pathological entity comprising a wide variety of neoplastic and non-neoplastic lesions. Even if most SMTs are benign tumors (e.g., leiomyomas), a smaller portion may have a malignant potential (e.g., gastrointestinal stromal tumor (GIST)). Preoperative diagnosis of SMT in bariatric patients may arise challenging clinical dilemmas. Long-term surveillance may be difficult after bariatric surgery. Moreover, according to SMT location, its presence may interfere with planned surgery. Submucosal tunneling endoscopic resection (STER) has emerged as an effective approach for minimally invasive en bloc excision of SMTs. This is the first case series of STER for SMTs before bariatric surgery.

METHODS

Seven female patients underwent STER for removal of SMTs before bariatric surgery. All lesions were incidentally diagnosed at preoperative endoscopy. STER procedural steps comprised mucosal incision, submucosal tunneling, lesion enucleation, and closure of mucosal defect.

RESULTS

En bloc removal of SMT was achieved in all cases. Mean procedural time was of 45 min (SD 18.6). No adverse event occurred. Mean size of the lesions was 20.6 mm (SD 5.8). Histological diagnoses were 5 leyomiomas, 1 lipoma, and 1 low grade GIST. Bariatric procedure was performed after a mean period of 4.1 months (SD 1.6) from endoscopic resection.

CONCLUSION

STER is a safe and effective treatment for the management of SMT even in bariatric patients awaiting surgery. Preoperative endoscopic resection of SMTs has the advantages of reducing the need for surveillance and removing lesions that could interfere with planned surgery. STER did not altered accomplishment of bariatric procedures.

Third Space Endoscopy: Lessons Learnt From a Decade of Submucosal Endoscopy

The field of third space endoscopy (TSE), also called submucosal endoscopy using a mucosal flap valve, allows secure access to the submucosal and deeper layers of the gastrointestinal tract without the risk of a full-thickness perforation. Since the first description of per-oral endoscopic myotomy (POEM) for the treatment of achalasia cardia 10 years ago, this field has expanded rapidly. Several new procedures, submucosal tunneling endoscopic resection, gastric-POEM, Zenker POEM, per-rectal endoscopic myotomy, diverticular POEM, and recanalization for complete esophageal obstruction (per-oral endoscopic tunneling for restoration of the esophagus), have been performed. All TSE procedures employ a similar technique-after a mucosal incision, a submucosal tunnel is created, a myotomy is performed, or a subepithelial tumor is resected distal to the site of mucosal incision, after which the mucosal incision is closed. Potential indications for TSE include resection of subepithelial tumors in the esophagus, gastroesophageal junction, or stomach; refractory gastroparesis; Zenker diverticulum; Hirschsprung disease or other forms of megacolon; and recanalization for complete esophageal obstruction. Data are currently available for POEM, submucosal tunneling endoscopic resection, and gastric-POEM, although mainly in the form of retrospective studies, and randomized trials and long-term follow-up data are limited. Submucosal endoscopy has an excellent safety profile with very few intraoperative adverse events, the majority being related to insufflation, although bleeding, perforation, and sepsis have been reported. TSE procedures require special training and have demonstrated a learning curve.