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

Endoscopic resection for the treatment of non-gastric gastrointestinal stromal tumors: A retrospective study from a large tertiary hospital in China

BACKGROUND AND AIMS

Few studies on endoscopic resection (ER) for the treatment of non-gastric gastrointestinal (GI) stromal tumors (GISTs) have been conducted, and most have been case reports or case series. The aim of this study was to evaluate the effectiveness and safety of ER for non-gastric GISTs.

METHODS

From January 2010 to December 2022, 329 patients who were diagnosed with GISTs underwent ER. After excluding 302 patients with gastric GISTs, we retrospectively assessed the data of 27 patients with non-gastric GISTs. The main outcome measures were en bloc resection, complete resection, residual disease, recurrence, and complications.

RESULTS

A total of 15(55.6%) females and 12(44.4%) males with a mean age of 53.8 ± 11.0 years were assessed. There were 19 (70.4%) GISTs in the esophagus, 2 (7.4%) in the duodenum, 3 (11.1%) in the colon and 3 (11.1%) in the rectum. The median tumor size was 12.0 mm (range 4.0-35.0 mm). Most of the GISTs (20, 74.1%) were very low risk, and the remaining 7(25.9%) were low risk. Both en bloc resection and complete resection were achieved in 25(92.6%) patients. Piecemeal resection mainly resulted from a larger tumor size, an irregular shape, and an extraluminal growth pattern. No residual disease or recurrence was noted during the follow-up period. The median operation time was 23 min (range 2-125 min). After excluding the operation time of EER, the operation time was prolonged to 37 min (range 12-125 min). Only one patient experienced mild abdominal pain, leading to a complication rate of 3.7%. No severe complications requiring for surgical interventions occurred.

CONCLUSION

ER was an effective and safe method for non-gastric GISTs in selected cases. GISTs of a small size and regular shape with an intraluminal growth pattern require complete resection.

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.

Advances of endoscopic and surgical management in gastrointestinal stromal tumors

As one of the most common mesenchymal malignancies in the digestive system, gastrointestinal stromal tumors (GISTs) occur throughout the alimentary tract with diversified oncological characteristics. With the advent of the tyrosine kinase inhibitor era, the treatment regimens of patients with GISTs have been revolutionized and GISTs have become the paradigm of multidisciplinary therapy. However, surgery resection remains recognized as the potentially curative management for the radical resection and provided with favorable oncological outcomes. The existing available surgery algorithms in clinical practice primarily incorporate open procedure, and endoscopic and laparoscopic surgery together with combined operation techniques. The performance of various surgery methods often refers to the consideration of risk evaluation of recurrence and metastases; the degree of disease progression; size, location, and growth pattern of tumor; general conditions of selected patients; and indications and safety profile of various techniques. In the present review, we summarize the fundamental principle of surgery of GISTs based on risk assessment as well as tumor size, location, and degree of progress with an emphasis on the indications, strengths, and limitations of current surgery techniques.

Advances in endoscopic resection techniques of small gastric tumors originating from the muscularis propria

Gastrointestinal stromal tumors are common gastrointestinal tumors typically originating from the muscularis propria layer of the stomach. Small gastric stromal tumors are usually detected incidentally during routine endoscopic examination. Although they may have malignant potentially, controversies remain regarding the need for endoscopic resection of small gastric stromal tumors originating from the muscularis propria. According to the guidelines of the European Society of Medical Oncology, all gastrointestinal stromal tumors >2 cm in size should be resected with endoscopic surveillance recommended for tumors <2 cm. Endoscopic resection including endoscopic mucosal dissection (EMD), endoscopic submucosal dissection (ESD), submucosal tunneling endoscopic resection and snare assisted endoscopic resection. However, EMD and ESD procedures may be accompanied with serious complications including perforation, bleeding, and abdominal infection. Snare-assisted endoscopic resection is an alternative approach and has the advantages of a shorter procedure time and a low rate of perforation or bleeding. This study summarizes the safety and feasibility of a novel snare-assisted endoscopic resection technique and highlights the pros and cons of the different endoscopic approaches currently used for subepithelia small gastric tumors.

Comparable long-term survival of patients with colorectal or gastric gastrointestinal stromal tumors treated with endoscopic vs. surgical resection

BACKGROUND AND AIMS

With the development of endoscopic technology, endoscopic treatment has been widely used in Gastrointestinal stromal tumors (GISTs). However, population-based studies comparing the long-term results of patients who received endoscopic treatment vs. Surgery are lacking. We used the Surveillance, Epidemiology, and End Results (SEER) database to analyze the long-term survival of colorectal or gastric GISTs who underwent primary tumor resection (endoscopic therapy or surgery) in the USA.

METHODS

Patients with colorectal or gastric GISTs were selected from the SEER database between 2010 and 2015. Kaplan-Meier analyses and log-rank tests were used to evaluate the difference in the long-term survival between the endoscopic therapy group and the surgery group. We examined the association between different treatments and survival after using the multivariate cox proportional hazards model to adjust the relevant covariates. Besides, we used Propensity score matching (PSM) to overcome the different distributions of covariates between the two groups and then further compare the survival difference.

RESULTS

In total, 2355 patients were enrolled in our study, of which 1999 (84.9%) received surgical treatment and 356 (15.1%) received endoscopic treatment. There was no significant difference in overall survival (OS) between the two groups before PSM. The median OS (73.5 months vs. 72.2 months) and 5-year OS rate (85.7% vs. 81.5%) of endoscopic therapy were similar to surgical patients (P = 0.34). The median Cancer-specific survival (CSS) and 5-year CSS rate in the endoscopic treatment group were higher than the surgical group before PSM, with 81.3 months, 97.1% versus 78.8 months, 92.7% (P = 0.011). After adjusting for other clinical factors and PSM, the long-term OS and CSS did not significantly differ between those treated surgically and treated endoscopically.

CONCLUSION

Based on the American population, we preliminarily found that the long-term OS and CSS did not differ between patients undergoing endoscopic therapy and surgery.

Submucosal Tunneling Endoscopic Resection for Submucosal Tumors in the Proximal Esophagus

BACKGROUND

Submucosal tunneling endoscopic resection (STER) is widely applied for treatment of gastrointestinal submucosal tumors (SMTs) originating from the muscularis propria layer. However, the tumor location within the proximal esophagus makes STER a challenge for the endoscopists. The aim of this study was to summarize the technique skill and evaluate the outcomes of proximal esophageal STER.

STUDY DESIGN

A total of 72 patients with SMTs in the proximal esophagus undergoing STER were included from February 2019 to March 2021. Imaging 3-dimensional reconstruction was used for patients with large SMTs. Clinicopathological, endoscopic, and follow-up data were collected and analyzed.

RESULTS

In this study, all the tumors were removed completely and no gross disease was remaining. The en bloc resection was achieved in 90.28% of patients, and the complications rate was 6.95%. Three-dimensional reconstruction was used for 30 patients (41.67%) with large SMTs (transverse diameter >2.0 cm). Based on statistical analysis, tumors with irregular shape and larger size were the significant contributors to piecemeal resection. Larger tumors increase the risk of long operation time, and irregular tumor shapes increase the risk of complications. The median hospitalization time was 4 days. All of the complications were cured by conservative treatment. A median follow-up of 12 months was available, and all patients were free from local recurrence or distant metastasis during the study period.

CONCLUSIONS

STER is an effective and safe methodology for the resection of proximal esophageal SMTs. Tumor size and shape mainly impact the piecemeal resection rate, STER-related complications, and procedural difficulty.

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.

Surgical Resection Is Still Better Than Endoscopic Resection for Patients With 2-5 cm Gastric Gastrointestinal Stromal Tumours: A Propensity Score Matching Analysis

Background

The management of 2-5 cm gastric gastrointestinal stromal tumours (GISTs) is still debated between surgeons and endoscopists. We aimed to investigate short-term and long-term outcomes between surgical resection (SR) and endoscopic resection (ER).

Methods

This study included 67 and 215 patients between 2010 and 2020 who underwent ER and SR, respectively. After propensity score matching, the clinical outcomes were compared. Individual patient information that requires special instructions is also summarized.

Results

After matching, the operation time (P=0.005) and postoperative hospital stay (P=0.005) were significantly longer in the SR group than in the ER group. However, there were no significant differences in blood loss (P=0.741), resection margin (P=1.000) or time to liquid diet (P=0.055). Statistical differences were also seen in en bloc resection (P<0.001) and adverse events (P=0.027). The recurrence rate did not differ significantly between the two techniques, and the mitotic index and ulceration were identified as independent prognostic factors of progression-free survival.

Conclusions

ER might be comparable to SR for the treatment of 2-3 cm gastric GISTs. SR is still considered the standard treatment for 3-5 cm gastric GISTs, while the intraoperative and postoperative information of ER should be recorded in detail and closely evaluated. Surgical resection is recommended if the tumour has a high mitotic index or mucosal ulceration.

Video assisted thoracoscopy or laparoscopy for enucleation of esophageal leiomyoma: A seven-year single center experience of 75 cases

OBJECTIVE

Leiomyoma is the most common benign tumor of the esophagus. Extra mucosal enucleation is the standard treatment. Herein we evaluated the feasibility and the outcomes of Minimally Invasive Surgery (MIS) using video-assisted thoracoscopic (VATS) or laparoscopic surgery (VALS) for esophageal leiomyoma enucleation.

SUBJECTS AND METHODS

Retrospective study of patients who were treated via VATS or VALS for esophageal leiomyoma enucleation in "Hanoi Viet Duc Hospital" from 2010 to 2017 by the same operator. The operative approach, tumor size, complications and outcomes after surgery were recorded.

RESULTS

Seventy-five patients were included. Mean age was 41.9 (range 20-68) years. The male/female sex ratio was 2.1:1. Fifty-five patients had clinical symptoms (73.3%). Tumors were identified in the upper third (12%), middle third (51%), and lower third (37%) of the esophagus. Mean tumor size was 3.7 (range 2-11) cm. VALS enucleation was performed in 23 patients who had leiomyoma located near the cardia (gastroesophageal junction or abdominal esophagus). The remaining 52 patients underwent right (n=42) or left VATS (n=10). Five patients (6.7%) sustained esophageal mucosa injury during dissection, repaired by MIS without late morbidity. A mini-incision (2 mini-laparotomies and 1 thoracotomy) was required in three patients (4%) due to large tumor size or mucosal injury. The mean operative time was 105min in VATS and 174min in VALS. No major perioperative surgical or medical complications were reported. The mean duration of hospital stay was 7.2 (range 5-12) days.

CONCLUSIONS

MIS enucleation of esophageal leiomyoma is technically safe and associated with a high therapeutic success rate with low medico-surgical morbidity. VATS could be applied for almost all esophageal leiomyoma tumors; however, the VALS approach was preferred for tumors located near the gastroesophageal junction in order to create an anti-reflux valve after enucleation.

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.

Comparison of endoscopic versus laparoscopic resection for gastric gastrointestinal stromal tumors: A preliminary meta-analysis

BACKGROUND AND AIM

For localized disease, complete surgical resection is regarded as the "gold standard" therapeutic modality. With the rapid development of endoscopic techniques, endoscopic resection (ESR) has been confirmed as an efficient and safe alternative for the treatment of gastrointestinal stromal tumors (GISTs) in the stomach. Nevertheless, the management of gastric GISTs remains poorly defined. The purpose of this study is to evaluate the security and effectiveness of ESR with laparoscopic resection (LAR) for gastric GISTs.

METHODS

A literature search of online databases was conducted to identify relevant comparative studies of ESR and LAR procedures for gastric GISTs published before April 10, 2020. The cumulative data analysis was also performed utilizing the software STATA.

RESULTS

In total, 10 studies involving 1165 patients met the inclusion criteria for analysis (651 for ESR and 514 for LAR). From the results of meta-analysis, patients who underwent ESR experienced decreased operative time (P = 0.000), less intraoperative blood loss (P = 0.002), earlier time to diet (P = 0.000), shorter hospital stay (P = 0.000), and lower total charges (P = 0.000) compared with LAR. Moreover, there were no significant differences between these two approaches concerning tumor rupture, conversion rate to other procedure, complete resection rate, postoperative complication rate, recurrence rate, and disease-free survival.

CONCLUSIONS

Endoscopic resection, as an effective alternative treatment strategy with satisfactory outcomes, is acceptable for selective patients with gastric GISTs compared with LAR. Further well-designed randomized controlled trials with large samples are warranted to corroborate our observations.

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.

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.

Outcomes of submucosal tunneling endoscopic resection in upper gastrointestinal sub-epithelial tumors

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Submucosal Tunneling Endoscopic Resection 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.

Resection of early esophageal neoplasms: The pendulum swings from surgical to endoscopic management

Esophageal cancer is a highly lethal disease and is the sixth leading cause of cancer related mortality in the world. The standard treatment is esophagectomy which is associated with significant morbidity and mortality. This led to development of minimally invasive, organ sparing endoscopic therapies which have comparable outcomes to esophagectomy in early cancer. These include endoscopic mucosal resection and endoscopic submucosal dissection. In early squamous cell cancer, endoscopic submucosal dissection is preferred as it is associated with cause specific 5-year survival rates of 100% for M1 and M2 tumors and 85% for M3 and SM1 tumors and low recurrence rates. In early adenocarcinoma, endoscopic resection of visible abnormalities is followed by ablation of the remaining flat Barrett’s mucosa to prevent recurrences. Radiofrequency ablation is the most widely used ablation modality with others being cryotherapy and argon plasma coagulation. Focal endoscopic mucosal resection followed by radiofrequency ablation leads to eradication of neoplasia in 93.4% of patients and eradication of intestinal metaplasia in 73.1% of patients. Innovative techniques such as submucosal tunneling with endoscopic resection are developed for management of submucosal tumors of the esophagus. This review includes a discussion of various endoscopic techniques and their clinical outcomes in early squamous cell cancer, adenocarcinoma and submucosal tumors. An overview of comparison between esophagectomy and endoscopic therapy are also presented.

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.

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.

Surgery for duodenal gastrointestinal stromal tumor: A systematic review and meta-analysis of pancreaticoduodenectomy versus local resection

The purpose of this study is to assess the clinical outcomes and prognostic factors for survival of patients with duodenal gastrointestinal stromal tumors (GIST) who underwent pancreaticoduodenectomy (PD) or local resection (LR). PubMed database was searched for relevant studies. A meta-analysis was performed with Review Manager 5.3 software. Twenty-seven observational studies involving 1103 patients were included in the review. The overall morbidity and 30-day mortality was 27% and 0.5% respectively. The median (range) 5-year overall survival (OS) and disease-free survival (DFS) rates were 87% (60-100%) and 71% (44-100%) respectively. In meta-analyses, factors associated with shorter DFS included male sex, mitotic index >5/50 high-power fields, high risk, tumor size >5 cm, and the PD procedure. Factors associated with shorter OS included mitotic index >5/50 high-power fields and tumor size >5 cm. Patients in PD group had a higher incidence of mitotic index >5/50 HPF, a higher incidence of high-risk classification, a higher incidence of tumors in the second portion of the duodenum, a larger tumor size, a longer duration of operation, more intraoperative blood loss, a greater blood transfusion requirement, a higher morbidity rate, a longer hospital stay, and an increased recurrence rate than those in LR group. In conclusion, the current literature review demonstrates that the postoperative prognosis of duodenal GIST is promising and mainly affected by tumor factors. The choice of the surgical approach should depend on the anatomical location and tumor size.

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.

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.