Submucosal tunneling endoscopic resection using methylene-blue guidance for cardial subepithelial tumors originating from the muscularis propria layer

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.

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.

Clinical outcomes of endoscopic resection for the treatment of gastric gastrointestinal stromal tumors originating from the muscularis propria: a 7-year experience from a large tertiary center in China

BACKGROUND AND AIMS

Few studies have evaluated the value of endoscopic resection (ER) for the treatment of gastric gastrointestinal (GI) stromal tumors (GISTs) originating from the muscularis propria (MP) in a large population, and no studies have evaluated risk factors for piecemeal resection. This study aimed to evaluate the efficacy and safety of ER for gastric GISTs in a real-world setting and to explore factors associated with piecemeal resection.

METHODS

From January 2013 to December 2019, 185 patients with gastric GISTs originating from the MP were assessed. Clinicopathological and endoscopic data were collected and analyzed. Baseline characteristics of the en bloc resection and piecemeal resection groups were compared to evaluate predictive factors for piecemeal resection.

RESULTS

There were 71 males and 114 females with a mean age of 57.0 ± 9.7 years. The mean size of GISTs was 15 mm (range 4-65 mm). A total of 123 were very low risk, 52 were low risk, and ten were moderate risk. In this study, 103 GISTs were treated with endoscopic submucosal excavation (ESE), 68 GISTs were treated with endoscopic full-thickness resection (EFR), and 14 GISTs were treated with submucosal tunneling ER (STER). Either en bloc resection or complete resection was achieved in 160 (86.5%) patients. No recurrence was noted during follow-up. Only five patients experienced minor complications, with a complication rate of 2.7%. Multivariate analysis demonstrated that size (odds ratio [OR] 1.060, 95% confidence interval [CI] 1.004-1.118; P = 0.035) and shape (OR 5.434, 95% CI 1.638-18.027; P = 0.006) were independent predictors of piecemeal resection.

CONCLUSION

ER was effective and safe for the treatment of gastric GISTs originating from the MP. Piecemeal resection did not seem to affect the efficacy of ER, and no recurrence was noted during follow-up. Large size and irregular shape are risk factors related to piecemeal resection of ER.

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.

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.

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.

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 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.

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.

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).

Treatment of cardial submucosal tumors originating from the muscularis propria layer: submucosal tunneling endoscopic resection versus endoscopic submucosal excavation

BACKGROUND AND AIMS

Submucosal tunneling endoscopic resection (STER) is increasingly used for the treatment of submucosal tumors (SMTs) originating from the muscularis propria layer; however, endoscopic submucosal excavation (ESE) is still performed in many hospitals for its low-skill and experience requirements. This study aimed to compare STER with ESE for cardial SMTs.

METHODS

From March 2013 to February 2017, patients with cardial SMTs undergoing STER (n = 47) and ESE (n = 40) were retrospectively assessed. Clinicopathological, endoscopic, and complication data were compared between STER and ESE groups.

RESULTS

The 87 enrolled patients included 31 females and 56 males, aged 48.2 ± 9.8 years. Mean tumor size was 22.0 mm (range 5.0-80.0 mm) as evaluated by pathology. Demographic and lesion features were similar in both groups. Despite similar hospital stay duration and cost, ESE was superior to STER with reduced operation time (34 vs. 46 min, P = 0.013) and less clips required (3 vs. 5, P = 0.000). En bloc resection rates, complete resection rates, hospital stay duration, cost, complications, and hemoglobin levels were similar in both groups. Irregular-shaped SMTs were more likely to achieve piecemeal resection in both STER and ESE groups (all P < 0.05). Meanwhile, the piecemeal resection rate was significantly higher for larger tumors in the STER group.

CONCLUSION

Compared with ESE, STER does not show overt advantages for cardial SMTs. However, ESE is superior to STER for reduced operation time. Irregular tumor shape seems to be a risk factor for piecemeal resection in both STER and ESE.

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 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.