Endoscopic full-thickness resection and laparoscopic surgery for treatment of gastric stromal tumors

Lap-Endo cooperative surgery (LECS) in gastric GIST: updates and future advances

BACKGROUND

With advancements in the field of laparoscopic and endoscopic techniques leading to improved patient outcomes, open resection has become increasingly outdated for the treatment of gastric gastrointestinal stromal tumours (GIST). This is further superseded with the advent of laparoscopic and endoscopic cooperative surgery (LECS), an amalgamation of the two techniques to further improve results garnered while overcoming prior limitations each had individually.

METHODS

The electronic databases MEDLINE, Embase and PubMed were reviewed up to August 2021, using terms relating to LECS and gastric GIST. Relevant in-article references not returned in the searches were also considered.

RESULTS

Advancements in the field of laparoscopic and endoscopic techniques has led to improved patient outcomes, making open resection a thing of the past for gastric GIST. This has become even more apparent with the advent of LECS, coupling two cutting edge techniques to further improve results garnered while overcoming prior limitations each had individually. LECS has gained much favour by reducing surgical margins due to endoscopic visualisation without being limited to smaller tumours, allowing for better anatomical and functional preservation of prior anatomy. Furthermore, hybrid approaches have improved perioperative outcomes, with reduction in procedure time, post-procedure hospital stay and lesser complications. Additionally, subtypes of LECS such as inverted LECS, closed LECS, non-exposed endoscopic wall-inversion surgery (NEWS) and laparoscopy-assisted endoscopic full-thickness resection (LAEFR) have been developed that allows the abdominal cavity to not be exposed to tumour cells and gastric contents by extracting the lesion transorally.

CONCLUSIONS

LECS and its subtypes being a combination of two advanced techniques shows a synergistic effect that is promising. However, despite all these advantages of enhanced safety and certainty, there remains areas that require further improvement.

Comparison of efficacy and safety between endoscopic and laparoscopic resections in the treatment of gastric stromal tumors: a systematic review and meta-analysis

Background

There are still clinical controversy on the efficacy and safety of endoscopic resection (ER) and laparoscopic resection (LR) in the treatment of gastrointestinal stromal tumors (GISTs). The present study aimed to evaluate the safety and efficacy of ER in the treatment of GISTs by comparing the relative outcomes of ER to LR.

Methods

PubMed, Web of Science, Cochrane Library, and Embase were searched. Data were retrieved from January 2010 to January 2020 and subjected to a meta-analysis based on the intraoperative and postoperative outcomes of ER and LR. The intervention arm was treated by LR while the comparator arm was treated by ER. Relevant literature was selected based on the inclusion criteria, data was extracted, and quality evaluation of the included literature was carried out. The Newcastle-Ottawa Scale (NOS) was applied for assessing the quality of included studies. Heterogeneity between studies was assessed using the Cochrane χ2 test and I2 statistic, and Funnel plots and Egger's test were used to detect publication bias.

Results

The present analysis included 13 studies, comprising a total of 1,261 patients, (ER vs. LR: 543 vs. 718). The incidence rate of postoperative complications [odds ratio (OR), 0.400; P=0.001] was significantly lower in the ER group [3.3%; 95% confidence interval (CI), 0.015 to 0.055] than the LR group (8.9%; 95% CI, 0.03 to 0.17). The meta-analysis revealed that the recurrence rate following ER (1.7%; 95% CI, 0.005 to 0.033) was lower than that following LR (2.5%; 95% CI, 0.012 to 0.041). The R0 resection rate of ER (99%; 95% CI, 0.975 to 0.999) was similar to that of LR (100%; 95% CI, 0.995 to 1.000). No publication bias in this study (P>0.10), and the sensitivity analysis showed that the study was robust.

Conclusions

ER was safer and more efficient than LR in terms of all the outcomes, except the R0 resection rate. Thus, ER should be considered the treatment of choice. However, attention should be paid to the surgical margin status following ER.

Therapeutic Effects of 4 Surgical Approaches for Small Gastrointestinal Stromal Tumors: A Network Meta-analysis

This study aims to systematically evaluate the efficacy of endoscopic resection (ER), laparoscopic resection (LR), laparoscopic endoscopic cooperative surgery (LECS), and open surgery (OpS) for gastrointestinal stromal tumors with small diameters (≤5 cm). Relevant studies were collected through Pubmed, Cochrane Library, and Embase databases. Operative time, hospital stays, time to liquid diet, intraoperative bleeding, and complications were used as outcome indicators for meta-analysis. Twenty-four retrospective cohort studies with 2406 participants were analyzed. LR and OpS groups had longer operating time than the ER group. ER, LECS, and LR groups had decreased lengths of hospital stay than the OpS group. Moreover, patients in LR and LECS groups had fewer complications than those in the OpS group. Endoscopic operation for small gastrointestinal stromal tumors contributes to shortened lengths of surgery and hospital stay. This reduces intraoperative blood loss and promotes gastroenteric functional recovery without increasing the risk of complications or tumor recurrence.

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.

Comparison of endoscopic full-thickness resection and cap-assisted endoscopic full-thickness resection in the treatment of small (≤1.5 cm) gastric GI stromal tumors

BACKGROUND AND AIMS

With the increasing incidence of small GI stromal tumors (GISTs), endoscopic full-thickness resection (EFTR) and cap-assisted EFTR (EFTR-C) have been suggested as 2 effective resection methods. We aimed to compare the outcomes of EFTR and EFTR-C for the treatment of small (≤1.5 cm) gastric GISTs.

METHODS

This retrospective study included 67 patients who underwent EFTR and 46 patients who underwent EFTR-C at Nanjing Drum Tower Hospital. Clinicopathologic features, adverse events (AEs), and outcomes were compared between the 2 groups. Univariate and multivariate linear and logistic regressions were used to analyze the effects of the procedure on the therapeutic outcomes of patients and adjusted for covariates in the multivariate analysis.

RESULTS

The tumor size in the EFTR group tended to be larger (P = .005). The resection time in the EFTR-C group was shorter than that in the EFTR group (38.3 ± 20.7 minutes vs 15.0 ± 11.8 minutes, P < .001), which retained statistical significance with adjustment for the covariates (adjusted mean difference, 22.2; 95% confidence interval, 15.0-29.4; P < .001). The R0 resection rate of the EFTR group was 94.0% and of the EFTR-C group 97.8% (P = .355). The EFTR-C group was superior to the EFTR group in terms of perioperative therapeutic outcomes, AEs, and postoperative recovery. No recurrence occurred in the EFTR and EFTR-C groups.

CONCLUSIONS

EFTR-C was found to be the preferable technique for small (≤1.5 cm) gastric GISTs with shorter operation times, lower AEs, faster postoperative recovery, and shorter hospitalization times as compared with EFTR.

Comparison Among Endoscopic, Laparoscopic, and Open Resection for Relatively Small Gastric Gastrointestinal Stromal Tumors (<5 cm): A Bayesian Network Meta-Analysis

Background

Endoscopic resection (ESR) is a novel minimally invasive procedure for superficial tumors. Its safety, efficiency, and outcome for gastric gastrointestinal stromal tumors (gGISTs) less than 5 cm remains unclear compared to laparoscopic resection (LAR) and open resection (ONR). The current network meta-analysis aimed to review and analyze the available evidence of this question.

Methods

PubMed, Embase, Cochrane Library, and Web of Science databases were searched to identify eligible studies published up to July 6, 2020. The perioperative and long-term oncological outcomes among ESR, LAR, and ONR for gGIST (<5 cm) were estimated through the Bayesian network meta-analysis with a random-effect model.

Results

Fifteen studies with 1,631 patients were included. ESR was associated with a shorter operative time [mean difference, MD: -36; 95% confidence interval, CI (-55, -16)], a higher rate of positive margin [odds ratio, OR: 5.1 × 10¹⁰, 95% CI (33, 2.5 × 10³²)], and less costs [MD: -1 × 10⁴, 95% CI (-1.6 × 10⁴, -4.4 × 10³)] but similar time to resume flatus [MD: 0.52, 95% CI (-0.16, 1.1)] and diet [MD: -3.5, 95% CI (-5.6, -1.6)] compared to LAR. A higher rate of total complications [OR: 11, 95% CI (1.2, 140)] was observed in patients who received ESR compared to patients who received LAR. After excluding perforation from the total complication category, the difference of complication between ESR and LAR disappeared [OR: 0.87, 95% CI (0.22, 2.3)]. The recurrence rate [OR: 1.3, 95% CI (0.40, 4.5)] and disease-free survival [hazard ratio: 1.26, 95% CI (0.60, 2.63)] showed no significant difference between ESR and LAR. ESR was associated with better or equivalent perioperative and long-term outcomes compared to ONR, except for positive margin. A subgroup analysis (<2 and 2–5 cm) showed no significantly different results among these three procedures either.

Conclusion

ESR was shown to be a safe and efficient alternative procedure to both LAR and ONR for gGISTs less than 2 cm and within 2–5 cm, respectively, without worsening the oncologic outcomes. However, preoperative assessment of tumor site is of importance for the determination of procedures regarding the increased incidence of a positive margin related to ESR.

DOG1 expression is common in human tumors: A tissue microarray study on more than 15,000 tissue samples

DOG1 (Discovered on GIST1) is a voltage-gated calcium-activated chloride and bicarbonate channel that is highly expressed in interstitial cells of Cajal and in gastrointestinal stromal tumors (GIST) derived from Cajal cells. To systematically determine in what tumor entities and normal tissue types DOG1 may be further expressed, a tissue microarray (TMA) containing 15,965 samples from 121 different tumor types and subtypes as well as 608 samples of 76 different normal tissue types was analyzed by immunohistochemistry. DOG1 immunostaining was found in 67 tumor types including GIST (95.7%), esophageal squamous cell carcinoma (31.9%), pancreatic ductal adenocarcinoma (33.6%), adenocarcinoma of the Papilla Vateri (20%), squamous cell carcinoma of the vulva (15.8%) and the oral cavity (15.3%), mucinous ovarian cancer (15.3%), esophageal adenocarcinoma (12.5%), endometrioid endometrial cancer (12.1%), neuroendocrine carcinoma of the colon (11.1%) and diffuse gastric adenocarcinoma (11%). Low level-DOG1 immunostaining was seen in 17 additional tumor entities. DOG1 expression was unrelated to histopathological parameters of tumor aggressiveness and/or patient prognosis in cancers of the breast (n = 1002), urinary bladder (975), ovary (469), endometrium (173), stomach (233), and thyroid gland (512). High DOG1 expression was linked to estrogen receptor expression in breast cancer (p < 0.0001) and absence of HPV infection in squamous cell carcinomas (p = 0.0008). In conclusion, our data identify several tumor entities that can show DOG1 expression levels at similar levels as in GIST. Although DOG1 is tightly linked to a diagnosis of GIST in spindle cell tumors, the differential diagnosis is much broader in DOG1 positive epithelioid neoplasms.

What About Gastric Schwannoma? A Review Article

PURPOSE

Gastric schwannomas (GSs) are rare mesenchymal neoplasms of the gastrointestinal tract. Diagnosis is often achieved postoperatively, based on pathology reports of retrieved specimens. The aim of the present study is to follow up all patients with gastric schwannoma (Gs) undergoing endoscopic, partial, or more extended surgery and to evaluate the appearance of local or distant recurrence.

METHODS

A PubMed, Cochrane, and Embase systematic review of the literature has been performed. Original papers, review articles, and case reports published between 1988 and 2019 were considered eligible. All the studies who met the inclusion criteria were analyzed. Statistical analysis of data has been performed using GraphPad Prism 7 software.

RESULTS

Three hundred twenty-eight articles were found, and a total of 102 were included and analyzed in depth. Fifty-three papers reported the follow-up information, ranging from 1 to 417 months across different studies. Among them, 31 patients underwent endoscopic removal of the gastric lesions; 140 patients underwent local surgery, including wedge resection or partial gastrectomy; and 148 patients underwent subtotal or total gastrectomy. The median follow-up was of 27-38-33 months, respectively. No recurrence or distant metastasis was detected in the endoscopy group. Among local surgery group, liver metastasis was reported in one case; in extended surgery group, one patient died for multiple liver metastases.

CONCLUSIONS

Local or more extended surgery involved a larger cohort of patients and reported satisfactory long-term results compared with endoscopy group. Surgery in absence of a definite preoperative diagnosis is considered the gold standard treatment for resectable Gs.

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.

Direct endoscopic full-thickness resection for submucosal tumors with an intraluminal growth pattern originating from the muscularis propria layer in the gastric fundus

Background and aims

Endoscopic full-thickness resection (EFTR) is difficult to perform in a retroflexed fashion in the gastric fundus. The present study aims at exploring whether direct EFTR can be a simple, effective and safe procedure to treat intraluminal-growth submucosal tumors originating from the muscularis propria.

Methods

The patients with intraluminal-growth submucosal tumors originating from the muscularis propria in gastric fundus treated by direct EFTR between 01 January 2017 and 01 September 2018 were retrospectively reviewed. In addition, we analyzed the patients with intraluminal-growth submucosal tumors originating from the muscularis propria in gastric fundus treated by traditional EFTR. The differences in tumor resection time, cost-effectiveness, and complication rate were evaluated.

Results

Forty patients were enrolled in the present study, 20 patients of which were in the direct EFTR group and 20 patients of which were in the traditional EFTR group. En-bloc resections of gastric tumors were successfully performed in all 40 cases. There was no significant difference in the average tumor size of the two groups (24.3 ± 2.9 mm in direct EFTR group verus 24.0 ± 2.6 mm in the traditional group, p = 0.731), but significant difference existed in the operative time between two groups (35.0 ± 8.2 min in direct EFTR group verus 130.6 ± 51.9 min in the traditional group, p<0.05). No complications, such as postoperative bleeding and perforation, occurred in any groups.

Conclusions

Direct EFTR is a safe, simple and cost-effective procedure for SMTs with an intraluminal growth pattern originating from the muscularis propria layer in the gastric fundus.

Endoscopic submucosal excavation and endoscopic full-thickness resection for gastric schwannoma: five-year experience from a large tertiary center in China

BACKGROUND AND AIMS

Endoscopic resection (ER) is an effective and safe method for gastric submucosal tumors, mostly composed of gastrointestinal stromal tumors and leiomyomas. The role of ER in gastric schwannoma (GS) has rarely been described. Our aim was to evaluate the efficacy and safety of ER for GS.

METHODS

This is a retrospective study in consecutive patients who underwent ER for GS from March 2013 to October 2018 at our center. Clinicopathological, endoscopic, and follow-up data were collected and analyzed.

RESULTS

A total of 16 consecutive patients (9 females, 56.3%) were included, with a mean age of 50.4 years (range 25-75 years). The mean tumor size was 22.9 ± 15.1 mm (range 10-55 mm). Thirteen tumors (81.3%) were located in the middle third of the stomach and 12 tumors (75%) grew with intraluminal pattern. Endoscopic submucosal excavation (ESE) was performed in 7 patients while endoscopic full-thickness resection (EFTR) was done in 9 patients. R0 resection was achieved in 14 patients (87.5%). The mean operative time was 91.6 ± 52.8 min (range 36-203 min) and the mean postoperative length of hospital stays was 8.3 ± 2.7 days (range 6-13 days). No adverse events were encountered except for fevers in 2 patients. No patients required surgical resection or intervention. During long-term follow-up of mean 21.8 months (range 6-62 months), no residue, recurrence, or metastasis was observed.

CONCLUSIONS

ER is effective and safe for patients with GS with favorable long-term outcomes.

Comparison between laparoscopic and endoscopic resections for gastric submucosal tumors

BACKGROUND/AIMS

Open resection/laparoscopic resection (LR) is the traditional treatment of gastric submucosal tumor (G-SMT). The endoscopic resection (ER) technology provides good results for G-SMT treatment but lacks sufficient evidence-based evidence. This retrospective study aimed to compare the clinical efficacy of ER [endoscopic submucosal dissection (ESD), endoscopic submucosal excavation (ESE), and endoscopic full-thickness resection (EFR)] and LR [laparoscopic wedge resection (LWR) and laparoscopic subtotal gastrectomy (LSG)] for G-SMT.

PATIENTS AND METHODS

From January 2013 to January 2017, data of patients with G-SMT with tumor diameter <5 cm were collected from the database of The Affiliated Hospital of Qingdao University and classified based on surgical methods. Demographics, tumor characteristics, surgical outcomes, complications and tumor recurrence were recorded and compared.

RESULTS

Overall, 275 patients with G-SMT were enrolled: 152 underwent ER (ESD, n = 65; ESE, n = 23; EFR, n = 61) and 123 underwent LR (LWR, n = 93; LSG, n = 30). Age, sex, R0 resection rate, tumor location, type, recurrence and complications were not statistically significant (P > 0.05). The ER group had a significantly higher percentage of intraluminal tumor (94.1% vs 62.4%) and smaller tumor size (1.8 ± 0.8 vs 3.4 ± 1.2 cm) than the LR group. The ER group had less muscular tumors than the LR group (54.6% vs 70.7%). The ER group had no serosal tumor. The ER group had shorter hospitalization time, postoperative hospital stay and diet recovery time. The LR group had shorter operation time, less cost and less blood loss.

CONCLUSION

ER and LR are safe and effective treatments for SMT. For small intraluminally growing SMT, ER is better than LR.

Clinical evaluation of endoscopic resection for treatment of large gastric stromal tumors

BACKGROUND

Gastric stromal tumor is a digestive tract mesenchymal tumor with malignant potential, and endoscopic techniques have been widely used in the treatment of gastric stromal tumors, but there is still controversy over their use for large gastric stromal tumors (≥ 3 cm).

AIM

To evaluate the clinical long-term efficacy and safety of endoscopic resection for large (≥ 3 cm) gastric stromal tumors.

METHODS

All patients who underwent endoscopic resection or surgery at our hospital from 2012 to 2017 for pathologically confirmed gastric stromal tumor with a maximum diameter of ≥ 3 cm were collected. The clinical data, histopathologic characteristics of the tumors, and long-term outcomes were recorded.

RESULTS

A total of 261 patients were included, including 37 patients in the endoscopy group and 224 patients in the surgical group. In the endoscopy group, the maximum tumor diameter was 3-8 cm; the male: Female ratio was 21/16; 34 cases had low-risk tumors, 3 had intermediate-risk, and 0 had high-risk; the mean follow-up time was 30.29 ± 19.67 mo, no patient was lost to follow-up, and no patient received chemotherapy after operation; two patients with recurrence had low-risk stromal tumors, and neither had complete resection under endoscopy. In the surgical group, the maximum tumor diameter was 3-22 cm; the male: Female ratio was 121/103; 103 cases had low-risk tumors, 75 had intermediate-risk, and 46 had high-risk; the average follow-up time was 38.83 ± 21.50 mo, 53 patients were lost to follow-up, and 8 patients had recurrence after operation (6 cases had high-risk tumors, 1 had intermediate-risk, and 1 had low-risk). The average tumor volume of the endoscopy group was 26.67 ± 26.22 cm³ (3.75-120), all of which were less than 125 cm³. The average volume of the surgical group was 273.03 ± 609.74 cm³ (7-4114). Among all patients with a tumor volume < 125 cm³, 7 with high-risk stromal tumors in the surgical group (37.625 cm³ to 115.2 cm³) accounted for 3.8% (7/183); of those with a tumor volume < 125 cm³, high-risk patients accounted for 50% (39/78). We found that 57.1% (12/22) of patients with high-risk stromal tumors also had endoscopic surface ulcer bleeding and tumor liquefaction on ultrasound or abdominal computed tomography; the ratio of tumors positive for both in high-risk stromal tumors with a volume < 125 cm³ was 60% (3/5).

CONCLUSION

Endoscopic treatment is safe for 95.5% of patients with gastric stromal tumors with a tumor diameter ≥ 3 cm and a volume of < 125 cm³ without endoscopic surface ulcer bleeding or CT liquefaction.

Endoscopic full-thickness resection for gastric gastrointestinal stromal tumor originating from the muscularis propria

SUMMARY OBJECTIVE: This study retrospectively reviewed 46 cases of gastric gastrointestinal stromal tumors treated by endoluminal endoscopic full-thickness resection (EFR) microsurgery in our gastrointestinal endoscopy center. We aimed to evaluate the EFR for the treatment of gastric gastrointestinal stromal tumors originating from the muscularis propria. METHODS: A total of 46 patients with gastric gastrointestinal stromal tumors originated from the muscularis propria layer from January 2012 to June 2015 were treated with EFR. The patients were followed up with gastroscope and computed tomography (CT) for evaluation of therapeutic effect and safety. RESULTS: EFR was successfully accomplished to remove all tumors in 46 patients. The mean procedure time was 82.5±39.8min (56-188min). Except in 3 leiomyomas, pathological examination confirmed gastrointestinal stromal tumor (GIST) in 43 cases. None of the patients had occurred bleeding, peritonitis and other complications after EFR. Thereafter, all patients were followed up with gastro-scope after 1, 6,12 months. CONCLUSIONS: EFR is effective and safe for patients with gastric gastrointestinal stromal tumors originated from muscularis propria layer and has the advantage of less invasive treatment and higher tumor resection rate. It should be considered for further application.

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.

Evolving role of the endoscopist in management of gastrointestinal neuroendocrine tumors

Neuroendocrine tumors (NETs) are uncommon gastrointestinal neoplasms but have been increasingly recognized over the past few decades. Luminal NETs originate from the submucosa of the gastrointestinal tract and careful endoscopic exam is a key for accurate diagnosis. Despite their reputation as indolent tumors with a good prognosis, some NETs may have aggressive features with associated poor long-term survival. Management of NETs requires full understanding of tumor size, depth of invasion, local lymphadenopathy status, and location within the gastrointestinal tract. Staging with endoscopic ultrasound or cross-sectional imaging is important for determining whether endoscopic treatment is feasible. In general, small superficial NETs can be managed by endoscopic mucosal resection and endoscopic submucosal dissection (ESD). In contrast, NETs larger than 2 cm are almost universally treated with surgical resection with lymphadenectomy. For those tumors between 11-20 mm in size, careful evaluation can identify which NETs may be managed with endoscopic resection. The increasing adoption of ESD may improve the results of endoscopic resection for luminal NETs. However, enthusiasm for endoscopic resection must be tempered with respect for the more definitive curative results afforded by surgical treatment with more advanced lesions.

Gastric Schwannoma: A Tumor Must Be Included in Differential Diagnoses of Gastric Submucosal Tumors

Gastric schwannoma (GS) is a rare neoplasm of the stomach. It accounts for 0.2% of all gastric tumors and is mostly benign, slow-growing, and asymptomatic. Due to its rarity, GS is not widely recognized by clinicians, and the precise differential diagnosis between GS and other gastric submucosal tumors remains difficult preoperatively. The present study reports a case of GS misdiagnosed as gastrointestinal stromal tumor and reviews the clinical, imaging, and pathological features, treatment, and follow-up of 221 patients with GS previously reported in the English literature. Although GS is rare, the case reported in the current study highlights the importance of including GS in differential diagnoses of gastric submucosal tumors. Furthermore, the findings of the review suggest that although many cases are asymptomatic, the most common symptoms are abdominal pain or discomfort, not gastrointestinal bleeding, and malignant GSs present with clinical symptoms more commonly. Although large-sample multicenter studies on the efficacy, safety, and oncological outcomes of minimally invasive techniques are required, the findings presented herein may be helpful for clinicians when diagnosing or treating GS.

Comparison between submucosal tunneling endoscopic resection and endoscopic full-thickness resection for gastric stromal tumors originating from the muscularis propria layer

BACKGROUND

Both submucosal tunneling endoscopic resection (STER) and endoscopic full-thickness resection (EFTR) are effective method for treating gastric gastrointestinal stromal tumors (GISTs); however, little is known about the comparison between STER and EFTR. The aim of the study was to compare the safety and efficacy of STER and EFTR for treating gastric GIST.

METHODS

We retrospectively collected the clinical data about patients with gastric GISTs who received STER or EFTR at our hospital from April 2011 to June 2016. Epidemiological data (gender, age), tumor size, procedure-related parameters, complications, length of stay, cost and follow-up data were compared between STER and EFTR.

RESULTS

A total of 52 patients were enrolled, and 20 of them received STER, while the other 32 cases received EFTR. There was no significant difference between the two groups in terms of gender, age, concomitant diseases, tumor size, en bloc resection rate, operation time, complications, pathohistological grade of GIST, hospital stay and cost (P > 0.05). However, patients who received EFTR had a longer suture time and needed more clips to close the gastric-wall defect (STER vs EFTR, 291.5 ± 68.7 vs 380.6 ± 96.9s and 6.0 ± 1.2 vs 7.6 ± 1.6, P < 0.05). No recurrence was noted in the STER and EFTR groups during a mean follow-up of 10.9 and 23.8 months, respectively.

CONCLUSIONS

The treatment efficacy between STER and EFTR for treating gastric GISTs was comparable, and a large-scale, randomized study is necessary for a more confirmed conclusion.

Endoscopic full thickness resection for gastric tumors originating from muscularis propria

AIM: To do systematic review of current literature for endoscopic full thickness resection (EFTR) technique for gastric tumors originating from muscularis propria.

METHODS: An extensive English literature search was done till December 2015; using PubMed and Google scholar to identify the peer reviewed original and review articles using keywords-EFTR, gastric tumor, muscularis propria. Human only studies were included. The references of pertinent studies were manually searched to identify additional relevant studies. The indications, procedural details, success rates, clinical outcomes, complications and limitations were considered. For the purpose of review, data from individual studies was combined to calculate mean. No other statistical test was applied.

RESULTS: A total of 9 original articles were identified. Four articles were from same institute and the time frames of these studies were overlapping. To avoid duplication of data, only the study with patients over the longest time interval was included and other three were excluded. In total six studies were included in the final review. In our systematic review, the mean success rate for EFTR of gastric tumors originating from muscularis propria was 96.8%. The mean procedure time varied from a minimum of 37 min to a maximum of 105 min. There was no reported mortality from the technique itself. The most common histological diagnosis was gastrointestinal stromal tumors and leiomyoma. Gastric wall defect closure by either metallic clips or over the scope clip (OTSC) had similar outcomes although experience with OTSC was limited to smaller lesions (< 3 cm).

CONCLUSION: EFTR is a minimally invasive technique to resect gastric submucosal tumors originating from muscularis propria with a high success rate and low complication rate.