The increasing detection of submucosal tumors (SMTs) in the upper gastrointestinal tract (UGI) is due to the increased clinical use of endoscopy and imaging technology. Some of these SMTs have malignant potential and may cause clinical symptoms. Thus, it is recommended in clinical guidelines to consider resection of these SMTs. Endoscopic techniques have become widely used in the diagnosis and treatment of SMT in the UGI as compared with traditional surgery due to their advantages of minimally invasive, quick recovery, and economical cost. Recently, new endoscopic techniques and instruments have been continuously implemented, leading to revolutionary innovation in endoscopic treatments. However, the safety and efficacy of these innovative techniques remain unclear. Therefore, we have comprehensively summarized the various techniques used in the treatment of UGI tumors in recent years, evaluated the indications and effects of each technique, and compared their benefits and disadvantages. We hope that this review will provide a more comprehensive reference for clinical and endoscopic practitioners, and help them develop more individualized treatment plans for different patients. This will ultimately expand the patient population that can benefit from these innovative technologies.

Gastric subepithelial tumors (SETs) may harbor potential malignancy. Although it is well recognized that large SETs should be resected, the precise treatment strategy remains controversial. Compared to surgical resection, endoscopic resection (ER) has many advantages; however, ER of SETs in the cardia is challenging.

To evaluate the safety and efficacy of endoscopic full-thickness resection (EFTR) for the treatment of gastric cardia SETs.

We retrospectively reviewed data from all patients with SETs originating from the muscularis propria layer in the gastric cardia that were treated by EFTR or submucosal tunneling ER (STER) at Zhongshan Hospital Fudan University between November 2014 and May 2022. Baseline characteristics and clinical outcomes, including procedure times and complications rates, were compared between groups of patients receiving EFTR and STER.

A total of 171 tumors were successfully removed [71 (41.5%) tumors in the EFTR and 100 (58.5%) tumors in the STER group]. Gastrointestinal stromal tumors (GISTs) were the most common SET. The en bloc resection rate was 100% in the EFTR group vs 97.0% in STER group (P > 0.05). Overall, the EFTR group had a higher complete resection rate than the STER group (98.6% vs 91.0%, P < 0.05). The procedure time was also shorter in the EFTR group (44.63 ± 28.66 min vs 53.36 ± 27.34, P < 0.05). The most common major complication in both groups was electrocoagulation syndrome. There was no significant difference in total complications between the two groups (21.1% vs 22.0%, P = 0.89).

EFTR of gastric cardia SETs is a very promising method to facilitate complete resection with similar complications and reduced operative times compared to STER. In cases of suspected GISTs or an unclear diagnosis, EFTR should be recommended to ensure complete resection.

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.

Therapeutic gastrointestinal endoscopy is rapidly evolving, and this evolution is quite apparent for esophageal diseases. Minimally invasive endoluminal therapy now allows outpatient treatment of many esophageal diseases that were traditionally managed surgically. In this review article, we explore the most exciting new developments. We discuss the use of peroral endoscopic myotomy for treatment of achalasia and other related diseases, as well as the modifications that have allowed its use in treatment of Zenker diverticulum. We cover endoscopic treatment of gastroesophageal reflux disease and Barrett's esophagus. Further, we explore advanced endoscopic resection techniques.

A 69-year-old female complained of epigastric pain of 6 months' duration. Esophagogastroduodenoscopy showed a transversal submucosal tumor (SMT) in the lower esophagus. Subsequently, endoscopic ultrasonography showed a hypoechoic lesion (25 mm x 12 mm) originating from the muscularis propria layer.

The modification of NOTES (natural orifice transluminal endoscopic surgery) by mucosal safety flap has introduced us to the world of third space endoscopy (TSE). POEM (per-oral endoscopic myotomy) for achalasia cardia being its first vista, the realm expanded so that we can now remove en bloc a subepithelial/intramural tumor by POET (per-oral endoscopic tumor resection), perform G-POEM (gastric per-oral endoscopic myotomy) for refractory gastroparesis, restore esophageal continuity in complete obstruction by performing POETRE (per-oral endoscopic tunneling for the restoration of the esophagus), divide the septum in Zenker diverticulum completely with negligible risk of perforation by Z-POEM (Zenker per-oral endoscopic myotomy) and relieve constipation in Hirschsprung disease by PREM (per-rectal endoscopic myotomy). However, the real potential of TSE became evident with the introduction of POEM with fundoplication. TSE has opened the gates of the peritoneal cavity. Improved expertise and equipment will make the role of endoscopist complimentary to the surgeon with the dawn of a new field in therapeutic endoscopy.

This review intends to comprehensively discuss the various aspects of POEM for achalasia studied so far followed by a brief discussion about other applications of TSE and the future perspectives in this exciting field.

submucosal tunneling endoscopic resection (STER) can be an effective treatment for submucosal tumors (SMTs) in the esophagus and cardia. However, STER may be more difficult to perform in the stomach than in the esophagus due to special anatomical and physiological features. The feasibility of STER to remove gastric STMs has not been systematically investigated. Therefore, this meta-analysis aimed to evaluate the safety and efficacy of STER for gastric SMTs.

a comprehensive literature search of the Medline, Embase, PubMed, and Cochrane Library databases was conducted. Complete resection and en-bloc resection rates were considered as the primary outcome measures. The secondary outcome measure was the pooled estimate of complications.

nine studies including 301 patients with 305 lesions were finally included. The pooled estimate of en-bloc resections was 95.1 % (95 % CI: 88.9-97.9 %), Cochran's Q-test, p = 0.151, and the weighted pooled rate (WPR) for complete resection was 97.9 % (95 % CI: 93.6-99.3 %), Cochran's Q-test, p = 0.778. In addition, the pooled estimate of gas-related complications was 8.7 % (95 % CI: 4.6-15.9 %), Cochran's Q-test, p = 0.057. The pooled estimate for mucosal laceration was 4.2 % (95 % CI: 2.2-7.9 %), Cochran's Q-test, p = 0.572. The pooled estimate for delayed bleeding was 2.1 % (95 % CI: 0.9-4.8 %), Cochran's Q-test, p = 0.985. The pooled estimate of inflammation-related complications was 8.6 % (95 % CI: 5.2-13.9 %), Cochran's Q-test, p = 0.308.

STER is an effective and safe technique for removing gastric SMTs with low complications, and complications, when encountered, can be treated conservatively.

To analyze the types and properties of cystic lesions originating from the muscularis propria of the gastric cardia (CLMPGC), explore the growth pattern and anatomical characteristics, and evaluate the safety, feasibility, and clinical efficacy of endoscopic esophageal submucosal tunnel dissection (ESTD).

From September 2013 to July 2018, we treated 6 patients with CLMPGC whom we had diagnosed using endoscopy, endoscopic ultrasound (EUS), and Computed Tomography (CT) before the operations. ESTD was the best option for treatment for all these patients. Postoperative observation and follow-ups were performed, and the operational, clinical data, and treatment results are analyzed.

The mean age of the patients was 50.67 ± 11.59 years (male : female = 1 : 1). The only clinical manifestations the patients exhibited were upper abdominal discomfort. The diameter of the masses was 2.05 ± 0.73 (1.1-3.0) cm. The duration of the ESTD operation was 93.5 (82-256) mins, and the length of hospital stay was 7.50 ± 1.38 days. Postoperative pathology showed 4 cases of an epithelioid cyst, and 2 cases of mucocele with xanthogranuloma. There were no complications, such as hemorrhage, pneumothorax, and pleural effusion during and after the operation. No recurrence during the follow-ups was observed.

The CLMPGC were mainly mucocele and epidermoid cyst, in an expansive growth pattern, and these lesions had no distinct borders with the muscularis propria. The muscularis propria formed a complete wall of the lesion. There was no direct blood supply to the lesions from big blood vessels. Endoscopic esophageal submucosal tunnel dissection was a safe, feasible, and effective treatment for CLMPGC.

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.

Submucosal tunneling techniques have expanded the horizon of therapeutic endoscopy. One such procedure, submucosal tunneling endoscopic resection (STER), enables the endoscopic removal of gastrointestinal (GI) sub-epithelial tumors. In this study, we aimed to evaluate the safety and efficacy of STER in patients with sub-epithelial lesions localized to the upper GI tract.

Consecutive subjects with a sub-epithelial lesion of ≥ 1 cm size in the upper GI tract were enrolled in the study. STER was performed using the standard technique in an endoscopy suite. A modified technique (double-opening STER) was used in cases with difficult en bloc resection of the tumor. Outcome measures included technical success, en bloc resection rates, adverse events, and recurrence.

A total of 104 patients with sub-epithelial tumors were evaluated for STER. Of them, 44 subjects (mean age 44.68 ± 12.82, 52.3% males) underwent standard STER. Majority (31, 70.4%) of the lesions were located in the esophagus and cardia. Technical success and en bloc removal of the tumor were achieved in 97.7% and 88.4% of cases, respectively. There was no major adverse event. Minor adverse events were recorded in 7 (15.9%) cases. Majority (31, 70.4%) of the tumors originated from muscularis propria, followed by submucosa (8, 18.2%) and muscularis mucosa (5, 11.4%). The most common histological diagnosis was leiomyoma (59.1%) followed by GI stromal tumors (20.4%). At a mean follow up of 12.36 ± 7.63 months, there was no incidence of tumor recurrence in en bloc as well as piecemeal resection groups.

STER is a safe and efficacious procedure for sub-epithelial tumors in the upper GI tract. Novel strategies need to be developed to ensure en bloc removal of large lesions.

Submucosal tunneling endoscopic resection (STER) was initially used to remove submucosal tumors (SMTs) located at the esophagus and cardia; only few researchers have reported the feasibility of STER for gastric SMTs beyond cardia due to the technical difficulty, and little is known about the comparison of STER for cardia and non-cardia gastric SMTs. The purpose was to compare the feasibility and efficacy of STER for cardia and non-cardia gastric SMTs, as well as to explore the risk factors for failure of en bloc resection.

We retrospectively collected the clinical data about patients with gastric SMTs who received STER at our hospital from June 2012 to June 2018. Demographics, tumor size, procedure-related parameters, complications, hospital stay, and follow-up data were compared between cardia and non-cardia SMTs. And multivariate analyses were conducted to look for the risk factors for failure of en bloc resection.

A total of 46 SMTs were removed, and 25 of them were located at cardia, while the other 21 at non-cardia position. There was no significant difference between the two groups in terms of gender, age, tumor size, en bloc resection rate, operation time, complications, and hospital stay (p > 0.05). No recurrence was noticed in all the cases. Multivariate analyses revealed that irregular shape was an independent risk factor for failure of en bloc resection.

STER is feasible for both cardia and non-cardia gastric SMTs, and the efficacy between cardia and non-cardia location is comparable. Irregular shape was an independent risk factor for failure of en bloc resection.

Endoscopic full-thickness resection (EFTR) and submucosal tunneling endoscopic resection (STER) are the frontier of therapeutic endoscopic. These two methods rely on the skillset and equipment of endoscopic submucosal dissection (ESD) while going beyond the boundaries of the gastrointestinal lumen. They are both representatives of natural orifice transluminal endoscopic surgery, with STER being a direct off-shoot of peroral endoscopic myotomy (POEM). Both techniques are designed for the removal of gastrointestinal tumors originating from the muscularis propria but tend to be used in different organs and come with respective challenges. In this review we will go over the history, indication, technique and literature of these two techniques.

Endoscopic submucosal tunneling has evolved to allow endoscopic resection of subepithelial tumors of gastrointestinal tract without full-thickness perforation. This study aimed to investigate safety and efficacy of submucosal tunnel resection for these tumors.

Patients with subepithelial tumors (SET) located in esophagus, gastric cardia, lesser curvature, and antrum were recruited. The size of tumor was limited to < 40 mm. The procedures were performed under general anesthesia. A mucosal entrance was created 2 cm proximal to the SET after submucosal injection. Submucosal tunnel was then extended and the tumor was dissected and mobilized with intact overlying mucosa. After complete dissection, the tumors would be retrieved per orally and mucosal entrance closed by endoclips.

From June 2012 to December 2016, 51 patients with subepithelial tumors received POET. 39 patients had SET in stomach, 11 located in esophagus, and 1 in duodenum. The mean operative time was 90.46 ± 46.49 min, while the mean size of the tumors was 20.71 ± 14.05 mm. The POET was converted to endoscopic full-thickness resection (EFTR) in three patients with gastric subepithelial tumors located at greater curvature. The overall complication rate was 4.0%, and there was no bleeding, mucosal dehiscence, or leakage. The time to resume diet was 1.7 days, while the average hospital stay was 3.2 ± 1.0 days. The mean follow-up period was 19 ± 16 months, and only 1 patient developed recurrence of leiomyoma.

Per oral endoscopic tumor resection is safe and effective treatment for esophageal and gastric SET located at cardia, lesser curvature, and antrum. Currently, POET for treatment of upper GI SET is limited by the size and location of the tumor.