Clinical impact of submucosal tunneling endoscopic resection for the treatment of gastric submucosal tumors originating from the muscularis propria layer (with video). Surg Endosc. 2015;29:3640-3646. [PMID: 25740640 DOI: 10.1007/s00464-015-4120-2]

Recent advances in endoscopic management of gastric neoplasms

The development and clinical application of new diagnostic endoscopic technologies such as endoscopic ultrasonography with biopsy, magnification endoscopy, and narrow-band imaging, more recently supplemented by artificial intelligence, have enabled wider recognition and detection of various gastric neoplasms including early gastric cancer (EGC) and subepithelial tumors, such as gastrointestinal stromal tumors and neuroendocrine tumors. Over the last decade, the evolution of novel advanced therapeutic endoscopic techniques, such as endoscopic mucosal resection, endoscopic submucosal dissection, endoscopic full-thickness resection, and submucosal tunneling endoscopic resection, along with the advent of a broad array of endoscopic accessories, has provided a promising and yet less invasive strategy for treating gastric neoplasms with the advantage of a reduced need for gastric surgery. Thus, the management algorithms of various gastric tumors in a defined subset of the patient population at low risk of lymph node metastasis and amenable to endoscopic resection, may require revision considering upcoming data given the high success rate of en bloc resection by experienced endoscopists. Moreover, endoscopic surveillance protocols for precancerous gastric lesions will continue to be refined by systematic reviews and meta-analyses of further research. However, the lack of familiarity with subtle endoscopic changes associated with EGC, as well as longer procedural time, evolving resection techniques and tools, a steep learning curve of such high-risk procedures, and lack of coding are issues that do not appeal to many gastroenterologists in the field. This review summarizes recent advances in the endoscopic management of gastric neoplasms, with special emphasis on diagnostic and therapeutic methods and their future prospects.

Suturing techniques with endoscopic clips and special devices after endoscopic resection

Endoscopic submucosal dissection is an established method for complete resection of large and early gastrointestinal tumors. However, methods to reduce bleeding, perforation, and other adverse events after endoscopic resection (ER) have not yet been defined. Mucosal defect closure is often performed endoscopically with a clip. Recently, reopenable clips and large-teeth clips have also been developed. The over-the-scope clip enables complete defect closure by withdrawing the endoscope once and attaching the clip. Other methods involve attaching the clip-line or a ring with an anchor to appose the edges of the mucosal defect, followed by the use of an additional clip for defect closure. Since clips are limited by their grasping force and size, other methods, such as endoloop closure, endoscopic ligation with O-ring closure, and the reopenable clip over-the-line method, have been developed. In recent years, techniques often utilized for full-thickness ER of submucosal tumors have been widely used in full-thickness defect closure. Specialized devices and techniques for defect closure have also been developed, including the curved needle and line, stitches, and an endoscopic tack and suture device. These clips and suture devices are applied for defect closure in emergency endoscopy, accidental perforations, and acute and chronic fistulas. Although endoscopic defect closure with clips has a high success rate, endoscopists need to simplify and promote endoscopic closure techniques to prevent adverse events after ER.

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.

Subepithelial tumors: How does endoscopic full-thickness resection & submucosal tunneling with endoscopic resection compare with laparoscopic endoscopic cooperative surgery?

Background and study aims  Endoscopic techniques are rapidly emerging for resection of subepithelial tumors (SETs). Submucosal tunneling for endoscopic resection (STER), endoscopic full-thickness resection (EFTR) and laparoscopic endoscopic cooperative surgery (LECS) are current alternatives to open surgery. In this study, we aimed to compare the three endoscopic techniques. Patients and methods  Consecutive patients who underwent resection of a submucosal esophageal or gastric lesion at several tertiary care centers were included in a dedicated registry over 3 years. Demographics, size and location of resected lesion, histology of specimen, length of procedure, adverse events (AEs), duration of hospital stay, and follow-up data were collected. Results  Ninety-six patients were included (47.7 % male, mean age 62): STER n = 34, EFTR n = 34, LECS n = 280. The lesions included leiomyoma, gastrointestinal stromal tumors (GISTs) and other. The mean lesion size was 28 mm (STD 16, range 20-72 mm). The majority of lesions in the EFTR and laparoscopic-assisted resection group were GISTs. There was no significant difference in clear resection margins, post-procedure complication rates, recurrence rate and total follow-up duration between the groups. However, the LECS group had a procedure time at least 30 minutes longer than STER or EFTR ( P  < 0.01). Total hospital stay for the laparoscopic-assisted resection group was also longer when compared to STER (1.5) and EFTR (1.8) ( P  < 0.01). Conclusions  STER, EFTR, and laparoscopic-assisted resection are efficacious approaches for resection of SETs with similar R0 resection rates, complication rates, and AE rates. Laparoscopic assisted resection appears more time-consuming and is associated with a longer hospital stay.

Advances in endoscopic resection: a review of endoscopic submucosal dissection (ESD), endoscopic full thickness resection (EFTR) and submucosal tunneling endoscopic resection (STER)

Subepithelial lesions are often detected incidentally in patients undergoing an endoscopy. They are common tumors of the gastrointestinal (GI) tract which can originate from different layers of the GI tract wall. These lesions can be further classified based on GI layer of origin and unique histochemical staining. While most are benign and asymptomatic, some of these lesions have malignant potential with distant metastases. However, current diagnostic modalities including endoscopy with biopsy or endoscopic ultrasound with fine needle aspiration are not always reliable. In addition, management of these lesions has historically involved surgical resection via open or laparoscopic approaches. In recent years, with advancement in endoscopic techniques and improvement in endoscopists' skills, less invasive procedures such as endoscopic submucosal dissection (ESD), endoscopic full thickness resection (EFTR) and submucosal tunneling endoscopic resection (STER) have been developed and now are being used by endoscopists worldwide. Upon reviewing the literature, multiple studies have shown the advantages of these endoscopic techniques when compared with surgical treatment. As a result, there has been a dramatic shift towards minimally invasive endoscopic procedures for the management of these subepithelial lesions. In this review article, we will discuss these endoscopic resection techniques in detail, their safety and efficacy, as well as comparison studies to other therapeutic modalities.

[Submucosal tunneling endoscopic resection for large esophageal leiomyoma: technical aspects and risk of complications]

We analyzed the technical aspects and risk of possible complications after submucosal tunneling endoscopic resection for large esophageal leiomyoma. A patient with a 4-cm non-epithelial esophageal tumor underwent STER procedure in June 2018. Surgery time was 130 min. There were no intraoperative complications. Postoperative period was complicated with mediastinitis with reactive pneumonia and pleural effusion accompanied by episodes of hyperthermia up to 38°C for 5 days. The patient was discharged in 12 days after complete resolution of pneumonia confirmed by chest X-ray. Contrast-enhanced examination after 3 postoperative days revealed no contrast agent leakage outside the esophagus. The previously applied clips were visualized. Endoscopic examination in 3 months after surgery visualized postoperative scar without signs of deformation and narrowing of the esophagus. No complaints were observed throughout 3.5-year follow-up period.

CONCLUSION

This report demonstrates the advantages of tunnel dissection ensuring organ-sparing procedure with the best functional result. However, intra- and postoperative complications are possible after STER. The risk of complications and complexity of surgery depend on transverse size (>3.5 cm), shape and localization of tumor. Larger neoplasm is accompanied by more difficult surgery and higher risk of complications. Therefore, adequate selection of patients for STER is essential.

Endoscopic Resection of Gastrointestinal Stromal Tumor: Is It Safe?

Recently, results from clinical studies of endoscopic resection of gastrointestinal stromal tumor (GIST) in the stomach are being reported. This procedure has several advantages, such as the provision of a definite diagnosis and therapeutic plan, avoidance of frequent follow-up examination, and reduction of patients’ anxiety. However, several concerns also exist such as a limited number of studies, low R0 resection rate, and relatively shorter follow-up period compared with surgical resection. Nevertheless, it is encouraging that most of the post-procedural complications have been treated with conservative management and that some of the patients did not show recurrence of the tumor during long-term follow-up. The selection of suitable cases and the experience of the endoscopists are the most important factors for successful endoscopic resection of gastric GIST. Development of novel procedures as well as collaboration with laparoscopic surgeons are currently in progress.

Submucosal tunneling endoscopic resection treatment of multiple gastrointestinal submucosal tumors

BACKGROUND AND AIM

Gastrointestinal submucosal tumors (SMTs) can be removed by submucosal tunneling endoscopic resection (STER). However, limited studies have evaluated STER for the removal of multiple upper gastrointestinal SMTs. The aim of this study was to evaluate the feasibility and outcomes of STER in the treatment of multiple upper gastrointestinal SMTs.

METHODS

From January 2011 to April 2020, the cases of patients with multiple upper gastrointestinal SMTs undergoing STER were retrospectively analyzed. Variables of clinicopathological characteristics, major adverse events (mAEs), and follow up were collected and analyzed.

RESULTS

Submucosal tunneling endoscopic resection was performed in 54 patients (48 male and 6 female patients) with 120 SMTs. Forty-four patients had two tumors, eight patients had three tumors, and two patients had four tumors. The median size of each patient was 1.8 cm (range 0.7 to 3.5 cm). Forty-five patients had tumors removed by one tunnel, and nine patients by two tunnels. The median procedure time was 50 min (range 14 to 120 min), and the mAE rate was 16.7% (9/54). No significant differences were found between patients with two tumors and those with > 2 tumors in terms of tunnel length, hospital stay, procedure time, and mAEs (all P > 0.05). In addition, patients with two tunnels had procedure time, hospital stay, and mAE rates comparable with those with one tunnel (all P > 0.05). No local recurrence or distant metastasis occurred during a median follow up of 64 months.

CONCLUSIONS

Submucosal tunneling endoscopic resection is a safe and effective technique for the resection of multiple upper gastrointestinal SMTs.

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.

A Review of Endoscopic Full-thickness Resection, Submucosal Tunneling Endoscopic Resection, and Endoscopic Submucosal Dissection for Resection of Subepithelial Lesions

Gastrointestinal subepithelial tumors (SETs) are often found while performing routine endoscopy. Recently, there has been the development of new endoscopic techniques such as endoscopic submucosal dissection, submucosal tunnel endoscopic resection, and endoscopic full-thickness resection, all minimally invasive approaches which have made it possible to resect SETs that were previously resected with surgery. This review discusses the endoscopic treatment of patients with SETs, outcomes for endoscopic treatment, procedure-related complications, and advantages and disadvantages of these endoscopic techniques.

Per-oral Endoscopic Myotomy and Other Applications of Third Space Endoscopy: Current Status and Future Perspectives

INTRODUCTION

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.

AREAS COVERED

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.

Efficacy and safety of submucosal tunneling endoscopic resection for gastric submucosal tumors: a systematic review and meta-analysis

INTRODUCTION

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.

MATERIAL AND METHODS

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.

RESULTS

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.

CONCLUSION

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

Submucosal Tunneling Endoscopic Resection

Minimally invasive endoscopic resection procedures continue to evolve, with submucosal tunneling endoscopic resection (STER) being a durable option for en bloc resection of submucosal tumors. Whether STER can be effectively used for larger (>3.5 cm) lesions remains to be seen. STER-ET is a novel approach for removal of extraluminal tumors, but data are currently limited to support its use.

Endoscopic Esophageal Submucosal Tunnel Dissection for Cystic Lesions Originating from the Muscularis Propria of the Gastric Cardia

Objective

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).

Methods

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.

Results

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.

Conclusion

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.

Current status of endoscopic submucosal tunnel dissection for treatment of superficial gastrointestinal neoplastic lesions

INTRODUCTION

With the widespread application of screening endoscopy and development of endoscopy-related instruments, more and more gastrointestinal cancers are detected in an early stage. Endoscopic resection is a preferred method for selected patients with superficial gastrointestinal neoplastic lesions, and endoscopic submucosal dissection (ESD) has become a standard method for its ability to perform en bloc resection regardless of the lesion size. ESD can be performed in a conventional or tunneling way, and the latter is termed endoscopic submucosal tunnel dissection (ESTD).

AREA COVERED

In the present review, we provided a comprehensive review on ESTD for treatment of superficial gastrointestinal neoplastic lesions. We mainly focus on technical details, safety and efficacy of ESTD for esophageal, gastric and colorectal lesions. The present review is expected to provide tips for operators who are going to perform ESTD.

EXPERT OPINION

The best indication of ESTD is large superficial esophageal neoplastic lesions (circumferential extent > 1/3 and longitudinal extent > 3 cm). Although ESTD has shown promising primary results for superficial gastric and colorectal neoplastic lesions, it is technically difficult and should be attempted only in experienced hands. Post-treatment stricture is a major concern, and preventive measures are recommended for patients with high risk of post-ESTD stricture.

Efficacy and Safety of Endoscopic Treatment for Gastrointestinal Stromal Tumors in the Upper Gastrointestinal Tract

Background/Aims:

Endoscopic treatment (ET) has been applied for decades to treat subepithelial tumors, including gastrointestinal stromal tumors (GISTs). However, the efficacy of ET remains debatable. In this study, we evaluated the efficacy and safety of ET for GISTs in the upper gastrointestinal tract.

Methods:

This retrospective single-center study included 97 patients who underwent ET. All patients were enrolled from July 2014 to July 2018. Parameters such as demographics, size, resection margin, complications, pathological features, procedure time, total cost, and follow-up were investigated and analyzed.

Results:

Our study achieved 100% en bloc resection and 77.4% (72/93) R0 resection. The most common location was the fundus with a mean tumor size of 2.1±1.4 cm. The mean age, procedure time, hospital stay, and cost were 59.7±11.3 years, 64.7±35.2 minutes, 6.8 days, and 5,337 dollars, respectively. According to National Institutes of Health classification, 63 (64.9%), 26 (26.8%), 5 (5.2%), and 3 (3.1%) patients belonged to the very low, low, intermediate, and high risk classification, respectively. Immunohistochemistry results showed a 100% positive rate of CD34, DOG-1, CD117, and Ki67. A mean follow-up of 21.3±13.0 months showed no recurrence or metastasis.

Conclusions:

ET is effective and safe for curative removal of GISTs in the upper gastrointestinal tract, and it can be a treatment of choice for patients with no metastasis.

Submucosal tunneling endoscopic resection for large symptomatic submucosal tumors of the esophagus: A clinical analysis of 24 cases

BACKGROUND/AIMS

Studies evaluating submucosal tunneling endoscopic resection (STER) for the treatment of upper gastrointestinal submucosal tumors (SMTs) have recently increased. However, the efficacy and safety of STER for the treatment of large symptomatic SMTs in the esophagus have not been well investigated. The aim of the present study was to evaluate the efficacy and safety of STER for the treatment of large symptomatic SMTs in the esophagus.

METHODS

A total of 24 patients with large symptomatic SMTs in the esophagus who underwent STER in our hospitals between January 2015 and May 2018 were included in the study. The tumors were confirmed to be of muscularis propria layer origin. Treatment outcomes, complications, and follow-up results were retrospectively analyzed.

RESULTS

All 24 lesions were resected en bloc with STER. The mean maximum transverse diameter of the lesions was 4.7 (3.5-6.5) cm. The mean maximum longitudinal diameter of the lesions was 2.1 (1.5-3.0) cm. The mean duration from mucosal incision to complete mucosal closure was 65 (50-115) min. Postoperative pathological diagnosis confirmed 18 cases with leiomyomas, 4 cases with stromal tumors, and 2 cases with schwannomas. There were no major complications. There were no residual lesions or disease recurrence during follow-up.

CONCLUSION

STER is safe and effective for the treatment of large symptomatic SMTs of muscularis propria layer origin in the esophagus.

Submucosal Tunneling Endoscopic Resection for Gastric Submucosal Tumors: a Comparison Between Cardia and Non-cardia Location

BACKGROUND AND PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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 of gastric gastrointestinal stromal tumor: a Japanese case series

Background:

Gastrointestinal stromal tumors (GISTs) are potentially malignant and are indicated for resection. The standard treatment for resectable GISTs is surgery, although endoscopic resection has been reported outside Japan. This study retrospectively analyzed the results of endoscopic resection of GISTs in Japan.

Method:

We identified patients with GISTs treated only by endoscopic resection in our institute between January 2016 and December 2018, and analyzed their clinical and pathological characteristics.

Results:

During the study period, 8 GISTs were resected only by endoscopy: 7 were located in the upper third of the stomach and 1 in the middle. All were intraluminal growth type. Median (range) tumor diameter was 20 (10-35) mm. All tumors were resected en bloc with a median (range) operation time of 67.5 (50-166) min. Complete perforation occurred in 5 cases, but the serosa remained in 2 and the outer layer of the muscularis propria remained in 1. The defect was endoscopically closed with clip-and-endoloop purse-string suturing (n=3), simple endoclipping (n=2), or over-the-scope clipping (n=2), and 1 did not require closure because the outer longitudinal muscle was preserved. Oral feeding was commenced on postoperative day (POD) 3 (median; range 2-4), and the patient was discharged on POD 6 (median; range 4-11). No serious adverse event developed after the procedures.

Conclusion:

Endoscopic resection for selected cases of small intraluminal GISTs is feasible, making it a viable alternative treatment option to laparoscopic surgery.

Snare combined with endoscopic clips in endoscopic resection of gastric submucosal tumor: a method of tumor traction

Background and study aims  Mucosal traction as a supportive technique is very useful for endoscopists during endoscopy. For gastric submucosal tumor (SMT), our team explored a method of pulling the SMT with a snare combined with endoclips (PSMT-SE). This study preliminarily explored its feasibility to assist resection of gastric SMT. Patients and methods  Operation-related data from patients who underwent gastric SMT removal assisted by PSMT-SE at the Gastrointestinal Endoscopy Center of Guangzhou Nanfang Hospital, China between January 2017 and October 2018 were retrospectively collected: tumor size and location, origin of tumor, total operation time, en bloc resection rate, intraoperative and postoperative complications. Results  Forty-two gastric SMTs in 41 patients were included in this study. Fifteen tumors were located in the gastric fundus, 11 in the gastric body, two in the gastric angle, 10 in the gastric antrum, and four in the greater curvature of the gastric fundus and the body junction. Further, 11 tumors originated from the submucosa and 31 originated from the muscularis propria. Endoscopic submucosal dissection and endoscopic full-thickness resection assisted by PSMT-SE were performed to resect 30 and 12 tumors, respectively. PSMT-SE could effectively expose the surgical field. Median diameter of resected tumors was 2.0 (0.7) cm, the total operation time was 45.5 (27.0) min, and the en bloc resection rate was 100 %. No intraoperative or postoperative complications were observed. Conclusion  PSMT-SE is a potentially useful method for assisting resection of gastric SMT with tumor traction. Further prospective studies with large sample sizes are warranted.

ASGE guideline for endoscopic full-thickness resection and submucosal tunnel endoscopic resection

With the development of reliable endoscopic closure techniques and tools, endoscopic full-thickness resection (EFTR) is emerging as a therapeutic option for the treatment of subepithelial tumors and epithelial neoplasia with significant fibrosis. EFTR may be categorized as "exposed" and "nonexposed." In exposed EFTR, the full-thickness resection is undertaken with a tunneled or nontunneled technique, with subsequent closure of the defect. In nonexposed EFTR, a secure serosa-to-serosa apposition is achieved before full-thickness resection of the isolated lesion. This document reviews current techniques and devices used for EFTR and reviews clinical applications and outcomes.

Comparison Between Submucosal Tunneling Endoscopic Resection (STER) and Other Resection Modules for Esophageal Muscularis Propria Tumors: A Retrospective Study

Background

Surgery has been considered to be the primary approach for resection of esophageal muscularis propria tumors. With the development of endoscopic technology, new techniques such as endoscopic submucosal dissection (ESD) and submucosal tunneling endoscopic resection (STER) have emerged for resecting these lesions. Previous studies have demonstrated that STER might be an intriguing alternative. This study aimed to evaluate the clinical value of STER by comparing it to other resecting modules.

Material/Methods

Clinical outcome and data were retrospectively collected from patients with esophageal muscularis propria tumors who underwent resection either endoscopically or thoracoscopically. The clinical data were statistically analyzed.

Results

A total of 137 patients were enrolled. They were divided into 3 groups: a STER group (27 patients), an ESD group (42 patients), and a thoracoscopic enucleation (TE) group (68 patients). There were no significant differences among the 3 groups in gender, age, pathological type of tumors, or major adverse events (P>0.05). However, the STER group had the shortest duration of hospitalization and the lowest cost (P<0.05). Furthermore, the STER group was superior in operation time and the location of tumors to the TE group. Moreover, STER outperformed ESD in the resection of large tumors (P<0.05). Although STER had the lowest en bloc resection rate, no recurrence or metastasis was noted during a mean follow-up of 22.14 months (range 3 to 60 months).

Conclusions

STER is a feasible, safe, and effective approach for the resection of esophageal muscularis propria tumors ≤40 mm. We recommend STER as a potent alternative for these tumors.

Endoscopic full thickness resection versus submucosal tunneling endoscopic resection for removal of submucosal tumors: a review article

Submucosal tumors (SMT) are protuberant lesions with intact mucosa that have a wide differential. These lesions may be removed by standard polypectomy, endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), or surgically. However, in lesions that arise from the muscularis propria, full thickness resection is recommended. This can be completed using either endoscopic full thickness resection (EFTR) or submucosal tunneling endoscopic resection (STER). EFTR can be accomplished by completing a full thickness resection followed by defect closure or by securing gastrointestinal wall patency before resection. STER is an option that first creates a mucosal dissection proximal to the lesion to allow a submucosal tunnel to be created. Using this tunnel, the lesion may be resected. When comparing STER to EFTR, there was no significant difference when evaluating tumor size, operation time, rate of complications, or en bloc resection rate. However, suture time, amount of clips used, and overall hospital stay were decreased in STER. With these differences, EFTR may be more efficacious in certain parts of the gastrointestinal tract where a submucosal tunnel is harder to accomplish.

Endoscopic resection for subepithelial lesions-pure endoscopic full-thickness resection and submucosal tunneling endoscopic 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.

Current Status of Endoscopic Resection of Gastric Subepithelial Tumors

Most gastrointestinal (GI) subepithelial tumors (SETs) are identified incidentally during endoscopic examination and are located in the stomach. Some SETs are malignant or have the potential to become malignant. Tumors originating from deeper layers, such as the muscularis propria or serosa, are not easy to diagnose and resect. Current guidelines recommend yearly endoscopic surveillance of SETs smaller than 2 cm. This recommendation may not be cost-effective in managing GI SETs. Endoscopic resection results not only in obtaining sufficient tissue for pathological diagnosis but also in resection and curing the tumor. Many different endoscopic methods for resection of GI SETs have been published in the literature. To avoid confusion, we have divided these methods into standard endoscopic submucosal dissection, modified endoscopic submucosal dissection, submucosal tunneling endoscopic resection, and nonexposed and exposed endoscopic full-thickness resection. These procedures offer less invasive approaches than surgery for resection of GI SETs and may be the most cost-effective in taking care of patients with GI SETs.

2007-2019: a "Third"-Space Odyssey in the Endoscopic Management of Gastrointestinal Tract Diseases

PURPOSE OF REVIEW

The main scope of this review article is to introduce readers to the innovative field of third-space endoscopy and offer a closer look at its history, milestones, and procedure spectrum while discussing ongoing and future challenges arising from its increasing adoption worldwide.

RECENT FINDINGS

Over the past few years, third-space endoscopy has been utilized in various diagnostic and interventional procedures performed throughout the gastrointestinal tract: obliteration of Zenker's diverticulum, myotomy for achalasia, gastroparesis or Hirschsprung's disease, biopsy or removal of subepithelial tumors, stricture management, post-per-oral endoscopic myotomy endoscopic fundoplication, and mediastino-, thoraco-, and peritoneoscopy. Third-space endoscopic interventions have revolutionized the management of esophageal motility disorders, gastroparesis, and gastrointestinal tract subepithelial tumors. Despite the high efficacy and safety of such interventions, some common (e.g., the high level of necessary endoscopic skill) and unique for each procedure (e.g., post-procedure gastroesophageal reflux or poor outcomes in patient subgroups) challenges still remain. Through a dedicated endoscopic training, a rigorous pre-procedure patient evaluation and selection, and the application of modified or new techniques, challenges can be overcome thus establishing existing procedures and paving the way for additional breakthroughs in the field of third-space endoscopy.

The retrospective comparison between submucosal tunneling endoscopic resection and endoscopic submucosal excavation for managing esophageal submucosal tumors originating from the muscularis propria layer

BACKGROUND

Submucosal tunneling endoscopic resection (STER) and endoscopic submucosal excavation (ESE) were recently introduced to cure submucosal tumors (SMTs) originating from the muscularis propria (MP) layer. This study aimed to compare clinical performance and safety of STER and ESE in treating esophageal SMTs originating from the MP layer.

METHODS

From January 2011 to December 2017, retrospective data collection and follow-up were applied for all STER or ESE cases with esophageal SMTs originating from the MP layer in our endoscopy center, including clinical characteristics, procedure success, efficacy, and adverse events. Subgroup analysis was further done based on tumor size and origin.

RESULTS

90 STER and 77 ESE were enrolled in this study. There were no significant difference for  patient characteristics, procedure performance, and complications for ESE and STER intervention (P > 0.05). STER was faster than ESE (3.90 mm²/min vs 2.82 mm²/min, P < 0.05). For large tumors (≥ 20 mm), both techniques had the similar performance (P > 0.05), while STER led to the shorter hospitalization (4.0d vs 7.0d, P < 0.05) and lower postoperative complication (16.3% vs 45.5%, P < 0.05). For small tumors (< 20 mm), STER achieved faster operation (STER vs ESE, 2.57 mm²/min vs 1.83 mm²/min, P < 0.05). Regardless of tumor origin, there were no significant difference for both techniques, but STER resulted in short hospitalization for SMTs from the deep MP layer (STER vs ESE, 5.0d vs 7.0d, P < 0.05). During the follow-up, 2 residual and 4 recurrence occurred in the STER group, as well as 1 residual and 2 recurrence in the ESE group.

CONCLUSIONS

Both STER and ESE were effective for treating esophageal SMTs originating from the MP layer. STER might be better due to its faster operation, less complications, and shorter hospitalization.

Efficacy and safety of submucosal tunneling endoscopic resection for upper gastrointestinal submucosal tumors with more than 1-year' follow-up: a systematic review and meta-analysis

Objectives: Submucosal tunneling endoscopic resection (STER) is a novel therapeutic approach for upper gastrointestinal submucosal tumors (SMTs) especially for tumors originating from the muscularis propria layer. Presently, several studies have reported the efficacy and safety of STER for SMTs. Therefore, we conducted this study to review the clinical outcomes of STER with more than 1-year' follow-up duration. Materials and methods: Medline, Embase and Cochrane databases were searched on November 2018 to identify studies reporting STER for SMTs. Weighted pooled rates were calculated for en bloc resection, complete resection and adverse event (AE). Risk ratios (RR) were calculated and pooled to compare STER with thoracoscopic enucleation (TE). Results: A total of 701 patients with 728 lesions from 12 original studies were review. Pooled WPR for en bloc resection of STER was 86.3% (95% CI: 74.5-93.1%), (I²=82.5). Pooled WPR for complete resection of STER was 97.7% (95% CI: 92.8-99.3%), (I²=77.6). WPR for AE was 18.3% (95% CI: 9.7-31.6%), (I²=90.6%). Two studies with 292 patients compared the performance of STER with TE. Pooled RR for en bloc resection was 1.02 (95% CI: 0.95-1.09). Pooled RR for complete resection was 1.0 (95% CI: 0.98-1.03). Pooled RR for AE was 0.82 (95% CI: 0.33-2.05). Conclusions: Our study showed that STER has relatively long-term efficacy for treating upper gastrointestinal SMTs, and the incidence of AE was not low for STER, but all of them can be managed conservatively.

Feasibility and safety of third-space endoscopic full-thickness resection in ex vivo and in vivo porcine models

Background and study aims  Endoscopic full-thickness resection (EFTR) involves several technical issues that need to be addressed. We devised a novel technique termed third-space EFTR and investigated its feasibility and safety in animal models. Methods  Third-space EFTR was performed in three isolated porcine stomachs (ex vivo) and four live pigs (in vivo, 1-week survival). The technique involved a circumferential mucosal incision, submucosal tunnelling on the proximal side, endoscopic suturing of the surrounding mucosa, a circumferential seromuscular incision in the submucosal tunnel, transoral retrieval and entry site closure of the tunnel. The technical outcomes were investigated. Results  In the ex vivo study, the procedure was successfully completed with R0 resection. In the in vivo study, the procedure was completed in all pigs; however, R0 resection failed in one pig owing to snaring resection. All pigs survived without severe adverse events. Conclusions  Our findings indicate that third-space EFTR is feasible and safe. This technique may be useful as a minimally invasive endoscopic option for reliable treatment of small gastric submucosal tumours.

Consensus on the digestive endoscopic tunnel technique

With the digestive endoscopic tunnel technique (DETT), many diseases that previously would have been treated by surgery are now endoscopically curable by establishing a submucosal tunnel between the mucosa and muscularis propria (MP). Through the tunnel, endoscopic diagnosis or treatment is performed for lesions in the mucosa, in the MP, and even outside the gastrointestinal (GI) tract. At present, the tunnel technique application range covers the following: (1) Treatment of lesions originating from the mucosal layer, e.g., endoscopic submucosal tunnel dissection for oesophageal large or circular early-stage cancer or precancerosis; (2) treatment of lesions from the MP layer, per-oral endoscopic myotomy, submucosal tunnelling endoscopic resection, etc.; and (3) diagnosis and treatment of lesions outside the GI tract, such as resection of lymph nodes and benign tumour excision in the mediastinum or abdominal cavity. With the increasing number of DETTs performed worldwide, endoscopic tunnel therapeutics, which is based on DETT, has been gradually developed and optimized. However, there is not yet an expert consensus on DETT to regulate its indications, contraindications, surgical procedure, and postoperative treatment. The International DETT Alliance signed up this consensus to standardize the procedures of DETT. In this consensus, we describe the definition, mechanism, and significance of DETT, prevention of infection and concepts of DETT-associated complications, methods to establish a submucosal tunnel, and application of DETT for lesions in the mucosa, in the MP and outside the GI tract (indications and contraindications, procedures, pre- and postoperative treatments, effectiveness, complications and treatments, and a comparison between DETT and other operations).

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

AIM

To evaluate the effectiveness and safety of submucosal tunneling endoscopic resection (STER) and compare its outcomes in esophageal and cardial submucosal tumors (SMTs) of the muscularis propria (MP) layer.

METHODS

From May 2012 to November 2017, 173 consecutive patients with upper gastrointestinal (GI) SMTs of the MP layer underwent STER. Overall, 165 patients were included, and 8 were excluded. The baseline characteristics of the patients and SMTs were recorded. The en bloc resection rate, complete resection rate, residual rate, and recurrence rate were calculated to evaluate the effectiveness of STER, and the complication rate was recorded to evaluate its safety. Effectiveness and safety outcomes were compared between esophageal and cardial SMTs.

RESULTS

One hundred and twelve men and 53 women with a mean age of 46.9 ± 10.8 years were included. The mean tumor size was 22.6 ± 13.6 mm. Eleven SMTs were located in the upper esophagus (6.7%), 49 in the middle esophagus (29.7%), 46 in the lower esophagus (27.9%), and 59 in the cardia (35.7%). Irregular lesions accounted for 48.5% of all lesions. STER achieved an en bloc resection rate of 78.7% (128/165) for GI SMTs with an overall complication rate of 21.2% (35/165). All complications resolved without intervention or were treated conservatively without the need for surgery. The en bloc resection rates of esophageal and cardial SMTs were 81.1% (86/106) and 72.1% (42/59), respectively (P = 0.142), and the complication rates were 19.8% (21/106) and 23.7% (14/59), respectively, (P = 0.555). The most common complications for esophageal SMTs were gas-related complications and fever, while mucosal injury was the most common for cardial SMTs.

CONCLUSION

STER is an effective and safe therapy for GI SMTs of the MP layer. Its effectiveness and safety are comparable between SMTs of the esophagus and cardia.

Clinical Overview of GIST and Its Latest Management by Endoscopic Resection in Upper GI: A Literature Review

Aims

To review the clinical presentation, diagnosis, assessment of risk of malignancy, and recent advances in management (mainly focusing on the role of endoscopic resection) of gastrointestinal stromal tumors (GISTs) in upper GI.

Method

We searched Embase, Web of science, and PubMed databases from 1993 to 2018 by using the following keywords: “gastrointestinal stromal tumors,” “GIST,” “treatment,” and “diagnosis.” Additional papers were searched manually from references of the related articles.

Findings

The improvement of endoscopic techniques in treating upper gastrointestinal subepithelial tumors especially gastrointestinal tumors has reduced the need for invasive surgery in patients unfit for surgery. Many studies have concluded that modified endoscopic treatments are effective and safe. These treatments permit minimal tissue resection, better dissection control, and high rates of en bloc resection with an acceptable rate of complications.

A comparison of submucosal tunneling endoscopic resection and endoscopic full-thickness resection for gastric fundus submucosal tumors

AIM

Both submucosal tunneling endoscopic resection (STER) and endoscopic full-thickness resection (EFTR) are effective methods for gastric fundus submucosal tumors (SMTs). However, there is little data that compares the two methods. The aim of this study was to compare the safety and efficacy of STER and EFTR for the treatment of SMTs in the gastric fundus.

METHODS

Clinical data was retrospectively collected from patients with gastric fundus SMTs who underwent STER or EFTR at our hospital from April 2011 to May 2016. Epidemiological data (gender, age), tumor size, procedure-related parameters, complications, postoperative hospital stay, cost and follow-up data were compared.

RESULTS

A total of 43 patients were enrolled: 15 underwent STER and the remaining 28 cases underwent EFTR. There were no significant differences between the two groups with regard to gender, age, tumor size, en bloc resection rate, operation time, pathohistological results and cost (p > 0.05). However, patients who underwent EFTR had a longer suture time, required a larger number of clips for closure and a prolonged postoperative hospital stay (p < 0.05). No recurrence was noted in either the STER or the EFTR group during a mean follow-up of 12.1 and 22.8 months, respectively.

CONCLUSIONS

The treatment efficacy of STER and EFTR for the treatment of gastric fundus SMTs was comparable. However, STER has some advantages over EFTR in terms of suture time, the number of clips required for closure and postoperative hospital stay.

Submucosal Tunneling Endoscopic Resection for Large and Irregular Submucosal Tumors Originating from Muscularis Propria Layer in Upper Gastrointestinal Tract

BACKGROUND

The majority of submucosal tumors (SMTs) are benign. However, large SMTs with irregular outer shapes are proved to harbor a higher risk for malignancy. Submucosal tunneling endoscopic resection (STER) has emerged as a feasible technique for resecting SMTs.

OBJECTIVE

To evaluate the safety and efficacy of STER for large and irregular SMTs with a diameter no <35 mm originating from the muscularis propria layer, and to share the technical skills of STER for complete and en bloc resection.

PATIENTS AND METHODS

We retrospectively reported 10 cases in which the new technique of STER was performed to remove large and irregular SMTs with a diameter no <35 mm of upper gastrointestinal tract in our hospital between April 2014 and April 2017.

RESULTS

All 10 (100%) patients underwent STER successfully, with a mean operation time of 156 minutes. Among the 10 SMTs, 3 (30%) were located in the esophagus, 7 (70%) were in the cardia. All the SMTs had a maximum diameter no <35 mm, ranging from 35 to 100 mm. The mean size was 57.2 mm. En bloc resection was achieved in 8 (80%) of the tumors. Only two (20%) of the SMTs were resected into more than one piece. Complication occurred in 1 (10%) of the patients as a representation of pneumothorax. No recurrence was noted during a median follow-up of 15 months.

CONCLUSION

In this retrospective study, STER may be an effective and safe technique resecting large and irregular SMTs with a diameter no >40 mm in transverse diameter and no >100 mm in longitudinal diameter.

Endoscopic Submucosal Tunnel Dissection for Upper Gastrointestinal Submucosal Tumors Originating from the Muscularis Propria Layer: A Single-Center Study

Background/Aims

In recent years, endoscopic submucosal tunnel dissection (ESTD) has gained popularity worldwide. The aim of this study was to evaluate the safety and efficacy of ESTD in treating upper gastrointestinal submucosal tumors (SMTs) in a large-volume endoscopic center.

Methods

Patients with SMTs were enrolled in this study between January 2012 and January 2015. Demographic data, clinical data, and treatment outcome were collected and analyzed.

Results

Seventy SMTs originating from the muscularis propria (MP) layer were identified in 69 patients. All patients successfully underwent the ESTD procedure. The mean procedure time was 49.0±29.5 minutes, and the mean tumor size was 18.7±7.2 mm. Among all lesions, the majority (70.0%) were located in the esophagus, 12.9% in the cardia, and 17.1% in the stomach. Complete resection was achieved in 67 lesions (95.7%). Perforation occurred in three patients (4.3%), who were treated by endoclips. Pneumothorax occurred in two patients (2.9%) and was successfully managed by thoracic drainage. During a median follow-up of 18.1 months, patients were free of local recurrence or distant metastasis.

Conclusions

Our results demonstrated the feasibility and safety of ESTD in treating upper gastrointestinal SMTs originating from the MP layer. Large-scale comparative studies with other treatment methods should be conducted in the future.

Endoscopic Full Thickness Resection

Recent advances in minimally invasive endoscopic approaches have pushed the boundaries of well-established resection techniques for therapeutic and diagnostic applications. Endoscopic full thickness resection techniques are a key development in the management of challenging epithelial and subepithelial lesions that are not amenable to conventional endoscopic resection methods and previously required a surgical approach. Endoscopic full thickness biopsy represents a paradigm shift in tissue acquisition and will enhance our understanding of the pathophysiology, and guide therapy, of gastrointestinal neuromuscular diseases, as well as other inflammatory and neoplastic conditions. This review highlights current tools and techniques available for endoscopic full thickness resection and biopsy, as well as outcomes from such interventions.

Endoscopic Submucosal Tunnel Dissection for Large Gastric Neoplastic Lesions: A Case-Matched Controlled Study

Aim

To evaluate the efficacy and safety of endoscopic submucosal tunnel dissection (ESTD) for resection of large superficial gastric lesions (SGLs).

Methods

The clinicopathological records of patients performed with ESTD or endoscopic submucosal dissection (ESD) for SGLs between January 2012 and January 2014 were retrospectively reviewed. 7 cases undergoing ESTD were enrolled to form the ESTD group. The cases were individually matched at a 1 : 1 ratio to other patients performed with ESD according to lesion location, ulcer or scar findings, resected specimen area, operation time and operators, and the matched cases constituting the ESD group. The treatment outcomes were compared between the two groups.

Results

The mean specimen size was 46 mm. 10 lesions were located in the cardia and 4 lesions in the lesser curvature of the lower gastric body. En bloc resection was achieved for all lesions. The mean ESTD resection time was 69 minutes as against 87.7 minutes for the ESD (P = 0.01). The mean resection speed was faster for ESTD than for ESD (18.86 mm²/min versus 13.76 mm²/min, P = 0.03). There were no significant differences regarding the safety and curability during the endoscopic follow-up (mean 27 months).

Conclusions

ESTD is effective and safe for the removal of SGLs and appears to be an optimal option for patients with large SGLs at suitable sites.

Short- and Long-Term Outcomes of Endoscope-Assisted Laparoscopic Wedge Resection for Gastric Submucosal Tumors Adjacent to Esophagogastric Junction

BACKGROUND

Laparoscopic wedge resection (LWR) is used to treat gastric submucosal tumors (SMTs). However, LWR can injure the cardia if tumors are near the esophagogastric junction (EGJ), resulting in gastric stenosis. This study's purpose was to summarize our experience with endoscope-assisted LWR for gastric SMTs within 3 cm of the EGJ and to verify the procedure's feasibility and safety.

METHODS

Data from 91 consecutive patients with gastric SMTs within 3 cm of the EGJ who underwent endoscope-assisted LWR at our hospital from 2007 to 2017 were obtained from a prospectively maintained database. The clinicopathological results, perioperative data, and long-term follow-up data were analyzed.

RESULTS

All patients successfully underwent endoscope-assisted LWR. The mean distance from tumor to EGJ was 2.43 ± 0.80 cm. Eighty-two patients underwent laparoscopic exogastric wedge resection (LEWR) and nine underwent laparoscopic transgastric wedge resection (LTWR). Mean operative time was 112.4 ± 48.8 min; mean blood loss was 36.8 ± 53.5 ml. Mean time to first flatus was 2.04 ± 0.68 days. Mean time to liquid intake was 2.53 ± 0.85 days. Mean postoperative hospital stay was 4.97 ± 1.80 days. Three patients (3.3%) had postoperative complications, all Clavien-Dindo grade I. The mean maximum tumor diameter was 3.00 ± 1.96 cm (range 0.5-10). LTWR was used more often than LEWR for SMTs in the posterior wall, those with intraluminal growth, and those closer to the EGJ. The mean follow-up time was 36.86 ± 29.73 months (range 3-126). There was no stenosis of EGJ or tumor recurrence. Sixteen patients (17.6%) complained of upper gastrointestinal symptoms during the follow-up, which were all relieved by usage of acid suppressive medications.

CONCLUSIONS

Endoscope-assisted LWR is safe, feasible, and effective for gastric SMTs near the EGJ. LTWR is preferable to LEWR for gastric SMTs in the posterior wall, those with intraluminal growth, and those closer to the EGJ.

Expanding Role of Third Space Endoscopy in the Management of Esophageal Diseases

OPINION STATEMENT: "Third space" endoscopy, also commonly referred as submucosal endoscopy, is founded on the principle that the deeper layers of the gastrointestinal (GI) tract can be accessed by tunneling in the submucosal space without compromising the integrity of the overlying mucosa. Peroral endoscopic myotomy (POEM), endoscopic submucosal dissection (ESD), and submucosal tunneling endoscopic resection (STER) are innovative techniques within the field of third space endoscopy in the management of esophageal disorders. POEM has become an accepted minimally invasive therapy for achalasia and related motility disorders with excellent short-term results, with early studies yielding similar efficacy to surgical myotomy and increased durability when compared to pneumatic balloon dilation (PBD). Data are needed to establish long-term outcomes with POEM, with particular interest on the incidence of gastroesophageal reflux, which appears to be higher than initially anticipated. ESD, a mature endoscopic resection technique in Asia, has recently gained traction in the West as a viable option for the management of early Barrett's esophagus (BE) neoplasia. Compared to standard endoscopic mucosal resection (EMR), ESD allows the en bloc resection of lesions irrespective of size, which may facilitate histological interpretation and reduce recurrence rates. Large prospective randomized controlled trials are needed to validate the efficacy and safety of this technique and to further define its role in the endoscopic armamentarium in early BE neoplasia. STER is an attractive technique that theoretically permits the resection of subepithelial esophageal tumors (SETs) arising from the deeper GI layers. Initial studies from highly experienced endoscopic centers support its technical feasibility and safety, although these results should be interpreted with caution due to variability arising from small numbers and heterogeneity among studies. Overall, third space endoscopy is an expanding field within endoscopic therapeutics for the treatment of esophageal diseases. While initial results have been very promising, large prospective studies, long-term data, and structured training programs with the establishment of competency parameters are needed before third space endoscopy can be advocated outside of highly specialized centers.

Endoscopic Treatment of Subepithelial Tumors

Gastrointestinal subepithelial tumors (SETs) are generally found during endoscopy and their incidence has gradually increased. Although the indications for the endoscopic treatment of patients with SETs remain to be established, the feasibility and safety of endoscopic dissection, including the advantages of this method compared with surgical treatment, have been validated in many studies. The development of endoscopic techniques, such as endoscopic submucosal dissection, endoscopic enucleation, endoscopic excavation, endoscopic submucosal tunnel dissection, submucosal tunnel endoscopic resection, and endoscopic full-thickness resection has enabled the removal of SETs while reducing the occurrence of complications. Here, we discuss the endoscopic treatment of patients with SETs, outcomes for endoscopic treatment, and procedure-related complications. We also consider the advantages and disadvantages of the various endoscopic techniques.

Endoscopic resection of gastric gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors in the gastrointestinal tract, and about 60% of them are found in the stomach. With the widespread application of endoscopy and endoscopic ultrasonography (EUS), more and more gastric GISTs are being found in an early stage (with a relative small diameter and no metastasis), giving the chance of complete resection. Endoscopic resection such as endoscopic band ligation (EBL), endoscopic submucosal dissection (ESD), endoscopic submucosal excavation (ESE), endoscopic full-thickness resection (EFTR) and submucosal tunneling endoscopic resection (STER), is a minimally invasive method compared with the conventional surgical approaches (open or laparoscopic), and has been demonstrated to be safe and effective for treating gastric GISTs. This review summarizes the recent advances on endoscopic resection of gastric GISTs, aiming to provide a rational management strategy for gastric GISTs.

Submucosal Tunneling Endoscopic Resection for the Treatment of Gastrointestinal Submucosal Tumors Originating from the Muscularis Propria Layer

Surgical resection and endoscopic resection comprise two alternative options for the treatment of submucosal tumors (SMTs) originating from the muscularis propria (MP) layer. Endoscopic resection is minimally invasive compared with surgical resection. Conventional non-tunneling techniques, such as endoscopic submucosal dissection (ESD), endoscopic submucosal excavation (ESE), and endoscopic full-thickness resection (EFR) have been demonstrated to be safe and effective. However, these techniques fail to maintain the integrity of the mucosa and induce high risk of perforation, infection, and postoperative strictures. Submucosal tunneling endoscopic resection (STER) is a novel surgical technique that can maintain the integrity of the mucosa by establishing a tunnel between the submucosal and the MP layers. STER has been proven to be effective and safe for the treatment of SMTs. Currently, STER has become a standard treatment for gastrointestinal (GI) SMTs originating from the MP layer, notably in China. In the present review, we describe the indications, procedures, postoperative care, efficacy and safety outcomes, and future perspectives of STER for GI SMTs originating from the MP layer.

Current status of submucosal tunneling endoscopic resection for gastrointestinal submucosal tumors originating from the muscularis propria layer

Gastrointestinal submucosal tumors (SMTs) have been increasingly identified via the use of endoscopic ultrasonography, and removal is often recommended for SMTs that are >2 cm in diameter or symptomatic. Submucosal tunneling endoscopic resection (STER), also known as submucosal endoscopic tumor resection, endoscopic submucosal tunnel dissection or tunneling endoscopic muscularis dissection, is a novel endoscopic technique for treating gastrointestinal SMTs originating from the muscularis propria layer, and has been demonstrated to be effective in the removal of SMTs with a decreased rate of recurrence by clinical studies. STER may be performed for patients with esophageal or cardia SMTs, and its application has expanded beyond these types of SMTs due to modifications to the technique. The present study reviewed the applications, procedure, efficacy and complications associated with STER.

Factors affecting the effectiveness and safety of submucosal tunneling endoscopic resection for esophageal submucosal tumors originating from the muscularis propria layer

BACKGROUND AND AIMS

Submucosal tunneling endoscopic resection (STER) has been proved to be effective and safe for esophageal submucosal tumors (SMTs) originating from the muscularis propria (MP) layer. This study was aimed to further evaluate the effectiveness, safety, and influencing factors especially the types of mucosal incision of STER in a larger population.

METHODS

A total of 89 patients undergoing STER with esophageal SMTs were retrospectively enrolled in this study from May 2012 to November 2016. Clinicopathological, endoscopic, and adverse events (AEs) data were collected and analyzed. Different incision methods were compared to evaluate the optimum incision method.

RESULTS

There were 27 females and 62 males with mean age of 46.5 ± 10.3 years. The medium size of the tumors was 16.0 mm (ranging 10.0-60.0 mm). Inverted T incisions were made in 29 (32.6%) patients, transverse incisions in 12 (13.5%) while longitudinal incisions in 48 (53.9%). En bloc resection was achieved in 70 (78.7%) patients. The residual rate was 1.1% (1/89), and no recurrence was noted even after piecemeal resection. The rate of AEs was 21.3% (19/89), and all of the AEs were cured without intervention or treated conservatively without the need for surgery. The en bloc resection rate was comparable among the three incision groups (P = 0.868); however, the incidence of AEs in the inverted T incision was lower than that in the longitudinal incision (P = 0.003). Fewer clips were used in the inverted T incision group than in the transverse incision group (P = 0.003).

CONCLUSIONS

Although STER failed to achieve en bloc resection in 21.3% patients, it was still an effective therapy owing to low residual rate and no recurrence rate after piecemeal resection. STER was safe with no severe AEs; however, minor AEs were common. Inverted T incision seems to be the optimum entry point.

A modified endoscopic method for resection of gastric submucosal tumor

BACKGROUND AND OBJECTIVE

Endoscopic mucosa-sparing lateral dissection (EMSLD) was developed by our group, and is used to remove gastric submucosal tumor (SMT). This study aims to evaluate the feasibility and safety of this method.

METHODS

This retrospective study included 25 patients who underwent EMSLDs at an endoscopy center as a national key unit in china from October 2015 to July 2016. The main data collected were the size of the gastric SMT, its location and origin, en bloc resection rate, operating time, intraoperative and postoperative complications, hospitalization expense, hospital days, and follow-up after hospital discharge.

RESULTS

The mean (SD) size of the gastric SMTs was 18.3 (5.9) mm; 96% (24/25) of the tumors originated in the muscularis propria; and 64% (16/25) and 28% (7/25) were located in the gastric fundus and gastric body, respectively. The rate of en bloc resection was 96% (24/25), and the rate of intraoperative perforations due to endoscopic full-thickness resection was 48% (12/25). All wounds and perforations were effectively closed using endoscopic clips combined with the retained mucosa. The mean operative time was 74.2 (38.0) min. Delayed bleeding and perforation were not observed.

CONCLUSION

Endoscopic mucosa-sparing lateral dissection is safe and feasible for the removal of gastric SMTs. The wound can be effectively closed using the retained mucosa and endoscopic clips, even if perforation has occurred. EMSLD provides an alternative to the resection of gastric SMTs, especially for tumors with a risk of intraoperative perforation.

Endoscopic submucosal tunnel dissection of upper gastrointestinal submucosal tumors: A comparative study of hook knife vs hybrid knife

AIM

To compare the efficacy and safety of a hook knife (HO) with a hybrid knife (HK) during endoscopic submucosal tunnel dissection (ESTD) procedure.

METHODS

Between August 2012 and December 2015, the ESTD procedure was performed for 83 upper GI submucosal lesions, which originated from the muscularis propria layer identified by upper endoscopy and endoscopic ultrasonography. Of these, 34 lesions were treated by a HO, whereas 49 lesions were treated by a HK. Data regarding age, gender, presenting symptoms, tumor location and size, procedure time, complications, en bloc resection rate and others were analyzed and compared between the two groups.

RESULTS

There were no significant differences in the age, gender, presenting symptoms and tumor location between the two groups. ESTD was successfully completed in all the patients, and no case was converted to laparoscopy. The mean procedure time was significantly shorter in the HK group than in the HO group (41.3 ± 20.3 min vs 57.2 ± 28.0 min, P = 0.004). The mean frequency of device exchange was 1.4 ± 0.6 in the HK group and significantly less than 3.3 ± 0.6 in the HO group (P < 0.001). The differences in tumor size and histopathological diagnoses were not significant between the two groups (P = 0.813, P = 0.363, respectively). Both groups had an equal en bloc resection rate and complete resection rate. Additionally, the complication rate was similar between the two groups (P = 0.901). During the follow-up, no recurrence occurred in either group.

CONCLUSION

We demonstrate for the first time that HO and HK do not differ in efficacy or safety, but HK reduces the frequency of device exchange and procedure time.

Submucosal tunneling endoscopic resection of upper gastrointestinal tract tumors arising from muscularis propria

The management of incidentally discovered small upper gastrointestinal (GI) tract submucosal tumors (SMT) remains debatable. In this review, we summarize the evolving experience with submucosal tunneling endoscopic resection (STER) of upper GI SMTs originating from the muscularis propria. From 16 original studies, we reviewed a total of 703 patients with 736 lesions. Of these, 436 were located in the esophagus, 146 in the esophagogastric junction (EGJ) and 154 in the stomach. The composite complete resection rate (CRR) for STER of upper GI tumors arising from the muscularis propria layer was 99.8% (445/446). The composite CRR for STER of esophageal, EGJ and gastric SMTs arising from the muscularis propria layer was 100% (208/208),100% (78/78)and 100% (115/115), respectively. The composite en bloc resection rate (EBRR) for STER of upper GI tumors arising from the muscularis propria layer was 94.6% (679/718). The composite EBRR for STER of esophageal, EGJ and gastric SMTs arising from the muscularis propria layer was 98.6% (205/208), 96.2% (75/78) and 97.9% (95/97), respectively. Tumor recurrence rate was 0%. The reported complication rate for STER was high but the majority responded to conservative management. STER is a minimally invasive and efficacious alternative to surgery, especially for patients with small tumors (<3 cm). Careful selection of candidates remains crucial for excluding potentially malignant tumors.