Current Status of Endoscopic Full-Thickness Resection for Gastric Subepithelial Tumors: A Literature Review Over Two Decades.

BACKGROUND: With the development of endoscopic technology and devices, endoscopic full-thickness resection (EFTR) has been challengingly introduced for gastric subepithelial tumors (SETs). The resection and closure strategies are under investigation. This systematic review was performed to assess the current status and limitations of EFTR for gastric SETs. SUMMARY: MEDLINE was searched using the keywords "endoscopic full-thickness resection" or "gastric endoscopic full-thickness closure" AND "gastric" or "stomach" from January 2001 to July 2022. The outcome variables were the complete resection rate, major adverse event (AE) rate including delayed bleeding and delayed perforation, and closure-associated outcomes. Among 288 studies, 27 eligible studies involving 1,234 patients were included in this review. The complete resection rate was 99.7% (1,231/1,234). The major AE rate was 1.13% (14/1,234), with delayed bleeding in two (0.16%) patients, delayed perforation in one (0.08%), panperitonitis or abdominal abscess in three (0.24%), and other AEs in eight (0.64%). Surgical interventions were required intraoperatively or postoperatively in 7 patients (0.56%). Three patients underwent intraoperative conversion to surgery, due to intraoperative massive bleeding, technical difficulty of closure, and retrieval of falling tumor in the peritoneal cavity. Postoperative surgical rescues for AEs were required in four (0.32%). Subgroup analysis of AE outcomes showed no significant differences among closure techniques consisting of endoclips, purse-string suturing, and over-the-scope clips. KEY MESSAGES: This systematic review demonstrated acceptable outcomes of EFTR and closure for gastric SETs, indicating that EFTR is a promising forthcoming procedure.

Reliability of endoscopic ultrasonography and endoscopy in measurement of gastric subepithelial tumor size.

BACKGROUND: Subepithelial tumor (SET) size is important in determining the treatment plan; however, size estimation for gastric SETs has not been well investigated. We aimed to investigate which method predicts SET size most accurately by retrospectively analyzing surgically removed SETs. METHODS: From January 2015 through June 2020, patients who underwent surgical gastric SET removal at Asan Medical Center, Seoul, Korea, were enrolled. SET sizes measured by pathologists and endoscopists were retrospectively reviewed. The reliability of SET size measurement by endoscopic ultrasonography (EUS) and endoscopy was calculated using intraclass correlation coefficient (ICC), with pathologic size as the gold standard. RESULTS: Overall, EUS was highly reliable (ICC 0.86, P < 0.001), and endoscopy was moderately reliable (ICC 0.75, P < 0.001). When analyzed according to SET location, endoscopy was highly reliable in the lesser curvature's lower third (ICC 0.86, P = 0.014), middle third (ICC 0.88, P < 0.001), and upper third (ICC 0.90, P < 0.001); as well as the anterior wall's middle third (0.84, P < 0.001) and the posterior wall's upper third (ICC 0.80, P < 0.001). EUS (ICC 0.96, P = 0.005) and endoscopy (ICC 0.95, P = 0.008) both were most reliable for lower-third posterior wall lesions, whereas endoscopy was unreliable for middle-third greater curvature lesions (ICC 0.41, P = 0.05). CONCLUSIONS: Both EUS and endoscopy were reliable methods for measuring gastric SET size, and overall, EUS was more reliable than endoscopy. In terms of SET location, EUS was consistently reliable, whereas endoscopy showed variable reliability. When measuring SET size by endoscopy, additional size measurements with EUS should be considered in certain locations.

Is it enough to observe less than 2 cm sized gastric SET?

BACKGROUND AND AIMS: The recent surge in demand for screening endoscopy has led to an increased detection of gastric subepithelial tumors (SETs). According to current guideline, SETs less than 2 cm in size are recommended for periodic surveillance. In light of recent advancement in therapeutic endoscopy in resection of small SET, we analyzed the histopathological features and the effectiveness of endoscopic resection for these small SETs. METHODS: Retrospectively study was performed on 74 patients who underwent endoscopic resection of gastric small (≤ 2 cm) upper gastrointestinal tract SETs. The outcomes including histopathology and en bloc resection were analyzed. RESULTS: The mean SET size was 11.69 ± 5.11 mm. The mean procedure time was 81.26 ± 42.53 min. Of the 74 patients, 28 patients had leiomyomas, 26 had gastrointestinal stromal tumors (GISTs), 14 had ectopic pancreas, 4 had lipomas, and 2 had neuroendocrine tumors. Among those with GIST, two patients exhibited high-risk histology. All patients underwent successful and uneventful endoscopy. CONCLUSIONS: Endoscopic resection can be recommended even for the small gastric SETs. In our study, we found that SETs with a size of less than 2 cm have significant proportion of GISTs which harbor malignant transformation potential.

Feasibility of endoscopic resection and impact of endoscopic ultrasound-based surveillance on colorectal subepithelial tumors.

BACKGROUND: Owing to the rising number of screening endoscopies and instrumental advances in endoscopic ultrasound (EUS), colorectal subepithelial tumors (SETs) are being increasingly detected. We aimed to determine the feasibility of endoscopic resection (ER) and the impact of EUS-based surveillance on colorectal SETs. METHODS: The medical records of 984 patients with incidentally detected colorectal SETs between 2010 and 2019 were retrospectively reviewed. Overall, 577 colorectal SETs underwent ER, and 71 colorectal SETs underwent serial colonoscopy for > 12 months. RESULTS: The mean tumor size (± standard deviation) of 577 colorectal SETs for which ER was performed was 7.0 ± 5.7 (median, 55; range, 1-50) mm; 475 tumors were located in the rectum and 102, in the colon. En bloc resection was achieved in 560/577 treated lesions (97.1%), and complete resection was achieved in 516/577 (89.4%). ER-related adverse events occurred in 15/577 (2.6%) patients. SETs originating from the muscularis propria showed a higher risk of ER-related adverse events and perforation than SETs arising from the mucosal or submucosal layer (odds ratio [OR] 19.786, 95% confidence interval [CI] 4.556-85.919; P = 0.002 and OR 141.250, 95% CI 11.596-1720.492; P = 0.046, respectively). Seventy-one patients were followed up after EUS without any treatment for > 12 months, during which three showed progression; eight, regression; and sixty, no changes. CONCLUSIONS: ER for colorectal SETs showed excellent efficacy and safety. Additionally, colorectal SETs without high-risk features in surveillance with colonoscopy showed an excellent prognosis.

Current status of endoscopic full-thickness resection with the full-thickness resection device.

Endoscopic full-thickness resection (EFTR) using the full-thickness resection device (FTRD) is an integral part of diagnostic and therapeutic endoscopy. Since its market launch in Europe in 2014, its safety and effectiveness have been proven in numerous studies. Adaptations in design as well as new techniques, such as hybrid EFTR, expand the spectrum of the FTRD system. The following review is intended to provide an overview of the clinical application and current evidence of EFTR with the FTRD system.

The necessarity of treatment for small gastric subepithelial tumors (1-2 cm) originating from muscularis propria: an analysis of 972 tumors.

BACKGROUND AND OBJECTIVES: Up till now, there are still controversies about the specific indication of endoscopic resection for small gastric subepithelial tumors (gSETs) originating from muscularis propria. We aimed to investigate the safety of endoscopic resection and postoperative pathology analysis. METHOD: The patients with primary small gSETs originating from muscularis propria, treated by endoscopic resection in the endoscopic center of Shengjing Hospital between January, 2011 and September, 2019 were enrolled. The complete resection rate, adverse events and clinicopathological features were recorded. RESULT: A total of 936 patients with 972 gastric SETs ≤ 2 cm originating from muscularis propria were included in our study. All the lesions were successfully treated by endoscopic resection. Nearly half of lesions were proved to be gastrointestinal stromal tumor (GIST) [n = 411 (42.3%)] according to postoperative pathology. All the objects were further subdivided into 2 groups, ≤ 1 cm, > 1 and ≤ 2 cm gSETs. The risk of gastric GIST of intermediate/high risk in the group (> 1 and ≤ 2 cm gSETs) is 8.41 times as that of gastric GIST in the group (the size of gastric ≤ 1 cm gSETs) (P < 0.05). CONCLUSION: Endoscopic resection is a safe and effective treatment for small gSETs. gSETs (1-2 cm) is more risky than gSETs (≤ 1 cm) and should be resected. This should be evaluated by further studies.

Tissue diagnosis necessary for small endoscopic ultrasound-suspected gastric gastrointestinal stromal tumors 2 cm or less in size: A prospective study focusing on the endoscopic incisional biopsy.

BACKGROUND AND AIM: The small endoscopic ultrasound (EUS)-suspected gastric gastrointestinal stromal tumors (GISTs), gastric subepithelial tumors at the muscularis propria layer on EUS, are detected frequently. Bite-on-bite forceps biopsy and EUS-guided tissue sampling yield variable results. This study aimed to analyze clinicopathologic features of the small EUS-suspected gastric GISTs 2 cm or less in size and to evaluate the efficacy and safety of the endoscopic incisional biopsy (EIB) for these small tumors. METHODS: This prospective study investigated 70 patients with small EUS-suspected gastric GISTs 2 cm or less in size in two stages. Firstly, 30 patients were recruited for the efficacy and safety evaluation of the EIB. Secondly, 40 patients were randomly assigned to receive either EIB or the bite-on-bite biopsy for comparison of the diagnostic yield, procedure time, and adverse event rate. RESULTS: Combining two study stages, leiomyoma (74%) was diagnosed histologically to outnumber GIST (26%) with a diagnostic rate of 94% for patients receiving EIB. KIT exon 11 mutations (50%) and PDGFRA exon 12 mutations (16%) were detected in the small gastric GISTs. In the direct comparison, the diagnostic yield of EIB and the bite-on-bite biopsy was 85% and 50%, respectively (P = 0.018). There was no statistically significant difference of the mean procedure time or adverse event rate between these two groups. CONCLUSIONS: Leiomyoma is more common than expected among these small tumors. Tissue diagnosis with an effective and safe sampling technique, such as EIB, is necessary for making further clinical decisions.

Diagnostic performance of endoscopic ultrasonography-guided fine-needle biopsy in upper gastrointestinal subepithelial tumors measuring 2-5 cm in size.

BACKGROUND: Subepithelial tumors (SETs) in the upper gastrointestinal (GI) tract are frequently discovered during upper endoscopy, and their management is determined based on size and histopathological diagnosis. We aimed to evaluate the diagnostic performance of endoscopic ultrasonography-guided fine-needle biopsy (EUS-FNB) in upper GI SETs of 2-5 cm in size. METHODS: We included 63 patients who underwent EUS-FNB for upper GI SETs of 2-5 cm in size between January 2013 and February 2020. The diagnostic yield of EUS-FNB, ability of EUS-FNB in discriminating malignant from non-malignant lesions, and histopathological concordance between EUS-FNB specimens and resected specimens were evaluated. RESULTS: Successful acquisition of macroscopic tissue cores was possible in all 63 cases, and the diagnostic yield of EUS-FNB was 92.1% (58/63). The sensitivity, specificity, and accuracy of EUS-FNB in discriminating malignant from non-malignant lesions were 100% (95% confidence interval [CI] 85.3-100%), 87.8% (95% CI 79.9-87.8%), and 92.1% (95% CI 81.8-92.1%), respectively. Of the 26 SETs that were endoscopically or surgically resected after EUS-FNB, the histopathological concordance rate between the EUS-FNB specimens and resected specimens was 100% (24/24), except in two cases of inadequate results with EUS-FNB specimens. CONCLUSION: EUS-FNB provides high diagnostic yield and high capability in discriminating malignant from non-malignant lesions in upper GI SETs of 2-5 cm in size.

Gastric subepithelial tumor: long-term natural history and risk factors for progression.

BACKGROUND: Subepithelial tumors are often detected incidentally during upper gastrointestinal endoscopy. However, their natural history and clinical management have yet to be clearly established. The aim of this study was to evaluate the natural history and risk factors for progression of gastric SETs. METHODS: The study retrospectively reviewed the medical records of patients who were diagnosed with gastric SET using upper gastrointestinal endoscopy between January 2005 and December 2017. Tumor progression was defined by a ≥ 25% increase in diameter. RESULTS: Among 3237 patients, 1859 underwent serial upper gastrointestinal endoscopy for more than six months. Endoscopic ultrasonography was further performed in 733 (39.43%) patients. Resection was performed in 73 (3.93%) patients. Tumor progressed in 138 (7.42%) patients over a mean follow-up period of 59.41 months (range, 5-215 months). In progressed tumors, the mean initial size was 15.01 mm (range, 2-50 mm) and the mean size increment was 12.86 mm (range, 3-50 mm). Large initial tumor size (OR: 1.03, 95% CI: 1.01-1.05), surface ulcer or erosion (OR: 2.47, 95% CI: 1.21-5.06), lobulated shape (OR: 3.76, 95% CI: 2.00-7.06), and middle-third location (OR: 1.65, 95% CI: 1.08-2.52) were significant risk factors for tumor progression. Large SETs had higher rates of progression and tended to grow faster than smaller tumors (r = 0.44, p < 0.001). CONCLUSIONS: The majority of gastric SETs did not increase in size during the long-term follow-up. Serial endoscopy may be sufficient as a follow-up tool for small SETs with intact overlying mucosa without lobulated shape.

Peroral endoscopic tumor resection (POET) with preserved mucosa technique for management of upper gastrointestinal tract subepithelial tumors.

BACKGROUND: Third space endoscopy technique facilitates therapeutic endoscopy in subepithelial space. This study aimed to investigate peroral endoscopic tumor resection (POET) with preserved mucosa technique for upper gastrointestinal tract subepithelial tumors (UGI-SETs) removal. METHODS: Between February 2011 and December 2019, consecutive patients with SETs of esophagus and stomach who underwent POET for enlarging size during follow-up, malignant endoscopic ultrasound features or by patient's request were enrolled. Demographic, endoscopic and pathological data were analyzed retrospectively. RESULTS: Totally 18 esophageal (mean ± SD age, 55.23 ± 4.15 year-old, 38.89% female) and 30 gastric (52.65 ± 2.43 year-old, 53.33% female) SETs in 47 patients (one with both esophageal and gastric lesions) were resected. The mean (± SD) endoscopic/pathological tumor size, procedure time, en-bloc/complete resection rate, and hospital stays of esophageal and gastric SET patients were 12.36 (± 7.89)/11.86 (± 5.67) and 12.57 (± 6.25)/12.35 (± 5.73) mm, 14.86 (± 6.15) and 38.21 (± 15.29) minutes, 88.89%/94.44% and 86.77%/93.30%, and 4.14 (± 0.21) and 4.17 (± 0.20) days, respectively. The overall complication rate was 18.75%, including 6 self-limited fever and 3 pneumoperitoneum relieved by needle puncture. There was no mortality or recurrence reported with mean follow-up period of 23.74 (± 4.12) months. CONCLUSIONS: POET is a safe and efficient third space endoscopic resection technique for removal of UGI-SETs less than 20 mm. Long term data are warranted to validate these results.

Clinical outcomes of cap-assisted endoscopic resection for small rectal subepithelial tumors.

OBJECTIVE: To assess the effectiveness and safety of cap-assisted endoscopic resection and the usefulness of endoscopic ultrasonography (EUS) for managing small rectal subepithelial tumors (SETs). PATIENTS AND METHODS: Patients with small rectal SETs≤10mm in diameter were enrolled in this study at our hospital from October 2014 to December 2017. First, EUS was performed to evaluate the lesions. Then, cap-assisted endoscopic resection was performed by suctioning the SET into a transparent cap, ligating with a metal snare and then resecting the tumor. The wound was closed using endoclips if necessary. RESULTS: Forty patients were enrolled in the study. EUS showed lesions originating from muscularis mucosa or submucosa with an average diameter of 5.4×3.1mm. The en bloc resection rate was 85.0% obtained by cap-assisted endoscopic resection, with a mean total procedure time of 17.6min. No immediate perforation happened. Immediate bleeding occurred in five patients; all cases were managed successfully by endoscopy. No delayed bleeding was observed. Pathology examination showed that 70.0% of the lesions were neuroendocrine tumors (G1). One case of recurrence was seen in follow-up; it was managed successfully by endoscopic submucosal dissection. There was no tumor recurrence in a median follow-up period of 41 months in the remaining 39 patients. CONCLUSIONS: Most small rectal SETs arising from the muscularis mucosa or submucosa are neuroendocrine tumors and require proper treatment. Cap-assisted endoscopic resection is simple, effective and safe for resecting such lesions, and EUS is useful for case screening.

Endoscopic full-thickness resection of gastric subepithelial tumors with the gFTRD-system: a prospective pilot study (RESET trial).

BACKGROUND: Gastric subepithelial tumors (SET) are rare and usually benign. However, up to 13% are malignant. Histology after conventional biopsy often is inconclusive. Surveillance endoscopies are the consequence in the majority of gastric SET cases. For SET arising from deeper layers endoscopic resection (ER) with the standard techniques is difficult and associated with the risk of perforation. The RESET trial further evaluates feasibility, efficacy and safety of clip-assisted endoscopic full-thickness resection (EFTR) for gastric SET using the novel gastric full-thickness-resection device (gFTRD). MATERIALS AND METHODS: The RESET trial was initiated in March 2017 (NCT03096236) and designed as prospective observational multicenter pilot trial. Gastric SET up to 15 mm were included. Primary endpoint was technical success (complete enbloc resection). Secondary endpoints were R0 resection, full-thickness resection, adverse events and recurrency at 3-months follow-up. For resection we used the gFTRD (Ovesco Endoscopy, Tübingen, Germany). RESULTS: 29 patients underwent gastric EFTR. Histology prior EFTR after conventional biopsy could define histological tumor type in only 31.2%. Primary endpoint was reached in 89.7%. Histology of the full-thickness-resection specimen could define histological tumor type in 100%. 76% of all SET could be resected histologically complete (R0) and a full-thickness-resection specimen could be obtained in 65.5%. In 31% periprocedural minor bleeding was observed and managed endoscopically. Follow-up was available in 79.3% (OTSC detachment in 78.3%, OTSC in position in 21.7%). No signs of residual or recurrent tumors were observed after 3 months. CONCLUSION: EFTR of gastric SET with gFTRD is feasible and safe. EFTR allows a definite histological diagnosis (including sufficient risk stratification in case of GIST or NET) in contrast to conventional biopsy. R0-resection is possible in most cases and might obviate the need for further surveillance endoscopies for selected patients.

Snare-assisted endoscopic resection of gastric subepithelial tumors originating from the muscularis propria layer: a multicenter study.

BACKGROUND AND AIM: Although successful endoscopic resection of gastric subepithelial tumors (SETs) originating from the muscularis propria (MP) layer has been frequently reported, it requires a relatively complicated technique and has a high perforation rate. In this retrospective study, we evaluated the efficacy and safety of the snare-assisted endoscopic resection (SAER) method which is performed using a snare and insulated-tip (IT) knife via a single-channel endoscope to reduce the perforation rate. METHODS: In this study, fifty-six patients with gastric SETs originating from the MP layer treated by the SAER method at three institutions between July 2017 and December 2017 were reviewed. The procedure involved multiple steps as shown in Fig. 2. Data were obtained on demographics, SET features, histopathological diagnoses, procedure time, en bloc resection rate, R0 resection (negative margins) status, and adverse events. RESULTS: Endoscopic resection was successfully performed in all patients. The median overall procedure time was 43.5 min (range 26-106 min). The mean size of resected specimens was 19.73 mm (range 10-33 mm). The overall rate of en bloc resection was 96.4% (54/56). In addition, the perforation rate was 7.1% (4/56), and defects in the stomach wall were very small and easily closed using metallic clips. No postprocedural bleeding occurred in any case. CONCLUSIONS: The SAER method is an effective, safe, less costly technique for the removal of some gastric SETs originating from the MP layer with an appropriate size.

Impact of endoscopic ultrasound-guided fine-needle biopsy on the diagnosis of subepithelial tumors: A propensity score-matching analysis.

BACKGROUND AND AIM: Immunohistological evaluations are essential for diagnosing subepithelial tumors (SET). However, endoscopic ultrasound-guided sampling using fine-needle aspiration (FNA) needles is limited in its ability to procure core tissue for immunostaining. Fine-needle biopsy (FNB) needles may mitigate this limitation. The present study aimed to examine the efficacy of FNB needles for procuring samples that enable the diagnosis of SET. METHODS: One hundred sixty patients were included in the study and separated into those whose samples were obtained using FNB needles (FNB group) and those whose samples were procured using FNA needles (FNA group). Groups were compared regarding the conclusive diagnosis rate and unwarranted resection rate. Propensity score matching was introduced to reduce selection bias. RESULTS: Rates at which conclusive diagnoses were reached through adequate immunohistological evaluations were 82% and 60% in the FNB and FNA groups, respectively; this difference was significant (P = 0.013). Unwarranted resection rate was significantly lower in the FNB group (2%) than in the FNA group (14%; P = 0.032). Multivariate analyses showed that lesions ≤20 mm were a significant risk factor for lower conclusive diagnosis rates following the use of FNB needles (P = 0.017). CONCLUSIONS: Fine-needle biopsy needles can be useful for obtaining samples that facilitate the diagnosis of SET and for avoiding unwarranted resections. However, FNB needles may be less advantageous for small SET.

Feasibility of a 20-gauge ProCore needle in EUS-guided subepithelial tumor sampling: a prospective multicenter study.

BACKGROUND: Endoscopic ultrasonography-guided fine-needle biopsy (EUS-FNB) may facilitate tissue acquisition for a definitive diagnosis of gastrointestinal subepithelial tumors (SETs). This study aimed to determine the diagnostic yield of EUS-FNB using a novel 20-gauge ProCore needle with a coiled sheath in tissue sampling of gastrointestinal SETs. METHODS: Between July 2016 and February 2017, 39 patients with gastrointestinal SETs were prospectively recruited from six university hospitals in Korea. Hypoechoic SETs ≥2 cm in size and originating from the submucosal and/or muscularis propria layer under EUS were eligible. This study was registered on ClinicalTrials.gov (NCT02884154). RESULTS: A total of 36 patients were included in the final analyses. EUS-FNB was diagnostic in 88.9% of SETs. Tissue adequacy was judged as optimal in 97.2% of FNB specimens according to on-site visual evaluation by endosonographers, and in 88.9% of specimens according to pathologists. A macroscopically optimal core sample was obtained with two needle passes in 94.4% of cases. Technical failure rate was encountered in two cases (5.6%) after two needle passes. There were two cases (5.6%) of bleeding, which was managed endoscopically. CONCLUSIONS: EUS-FNB using a 20-gauge ProCore needle is a technically feasible and effective modality for histopathologic diagnosis of gastrointestinal SETs, providing adequate core samples with fewer needle passes; ClinicalTrials.gov number, NCT02884154.

Endoscopic full-thickness resection of gastric and duodenal subepithelial lesions using a new, flat-based over-the-scope clip.

BACKGROUND: Surgical resection of upper gastrointestinal (GI) subepithelial tumors (SETs) is associated with significant morbidity and mortality. A new over-the-scope (OTS) clip can be used for endoscopic full-thickness resection (eFTR). We aimed to prospectively evaluate feasibility and safety of upper GI eFTR with a new, flat-based OTS clip. METHODS: Consecutive patients with a gastric or duodenal SET < 20 mm were prospectively included. After identification of the lesion, the clip was placed and lesions were resected. Patients were followed for 1 month to assess severe adverse events (SAEs); 3-6 months after eFTR, endoscopy was performed. RESULTS: eFTR was performed on 13 lesions in 12 patients: 7 gastric and 6 duodenal SETs. Technical success was achieved in 11 cases (85%). In all 11 cases, R0-resection was achieved. In all 6 duodenal cases and in one gastric case, FTR was achieved (64%). One SAE (pain) was observed after eFTR of a gastric SET. After eFTR of duodenal SETs, several SAEs were observed: perforation (n = 1), microperforation (n = 3), and hemorrhage (n = 1). During follow-up endoscopy, the clip was no longer in situ in most patients (7 of 10; 70%). CONCLUSIONS: eFTR with this new flat-based OTS clip is feasible and effective. Although gastric eFTR was safe, eFTR in the duodenum was complicated by (micro)perforation in several patients. Therefore, the design of the clip or the technique of resection needs further refinement to improve safety of resection of SET in thin-walled areas such as the duodenum before being applied in clinical practice. Dutch trial register: NTR5023.

Endoscopic full-thickness resection for gastrointestinal submucosal tumors.

Endoscopic full-thickness resection (EFTR) is a "changing-concept" endoscopic resection technique, which safely allows resecting deep submucosal tumors (SMTs) in the gastrointestinal (GI) wall. It's a highly promising endoscopic procedure that allows full-thickness excision of a small piece of the complete GI wall by using only a flexible endoscope. EFTR is a meeting point between surgery and endoscopy and probably the onset of many prospective combined minimally invasive therapeutic techniques that science will explore. In this review, use of the EFTR technique for gastrointestinal SMTs is highlighted, focusing on some technical aspects, indications, contraindications and outcomes.

Direct endoscopic biopsy for subepithelial tumor larger than 20 mm after removal of overlying mucosa.

OBJECTIVE: An accurate diagnosis of a subepithelial tumor (SET) using endoscopic ultrasound (EUS) without tissue acquisition is difficult. Treatment plan for a SET may be influenced by endoscopic tissue diagnosis. We aimed to clarify the clinical outcomes of direct endoscopic biopsy for SET after removal of the overlying mucosa. METHODS: We evaluated the medical records of 15 patients. All patients underwent direct endoscopic biopsy for a SET larger than 20 mm (involving proper muscle layer) after removal of the overlying mucosa. The rate of achieving an accurate diagnosis and the treatment decision after the procedure were evaluated. RESULTS: The patients' mean age was 55.1 ± 14.7 years. The patient population predominantly comprised men (9/15, 60%). The mean tumor size was 24.3 ± 7.8 mm. The mean biopsy number was 3.5 ± 1.7. No major complications occurred with the procedure. The mean procedure time was 15 ± 7.4 min. An accurate diagnosis was achieved in 93.3% of patients (14/15). The main pathological diagnoses after direct endoscopic SET biopsy were leiomyoma (33.3%, 5/15) and ectopic pancreas (33.3%, 5/15) followed by gastrointestinal stromal tumor (GIST) (13.3%, 2/15) and schwannoma (13.3%, 2/15). The treatment plan was influenced by the result of biopsy in 80% of patients (9/15), and unnecessary surgical resection was avoided. CONCLUSIONS: Direct endoscopic SET biopsy after removal of the overlying mucosa using an endoscopic conventional snare was a useful diagnostic tool with high diagnostic accuracy and low risk of complications.

Endoscopic resection for duodenal subepithelial tumors: a single-center experience.

BACKGROUND: Subepithelial tumors (SETs) in the gastrointestinal tract are often incidentally found during endoscopic examinations. Although the utility and safety of endoscopic resection (ER) of SETs in the esophagus and stomach have been described, data about the ER of duodenal SETs remain scant. Therefore, we aimed to investigate the clinical outcomes associated with the ER of duodenal SETs and to assess possible predictive factors for incomplete resection. METHODS: We conducted a retrospective observational study of 62 patients (64 lesions) that underwent ER of duodenal SETs between June 2005 and December 2015 at the Pusan National University Hospital. The therapeutic outcomes from ER and procedure-related complications were analyzed. RESULTS: Endoscopic mucosal resection (EMR) was performed in 38 tumors, EMR with a ligation device (EMR-L) in 18 and endoscopic submucosal dissection (ESD) in 8. The overall en bloc resection and complete ER rates were 96.9 % (62/64) and 100 % (64/64), respectively. The complete pathologic resection rate was 76.6 % (49/64). Multivariate logistic regression analyses determined that the macroscopic type (Yamada type I or II; odds ratio [OR] 6.460, 95 % confidence interval [CI] 1.569-37.458, p = 0.027) and the treatment method (ESD; OR 7.178, 95 % CI 1.291-39.323, p = 0.024) were independently associated with incomplete pathologic resection. The procedure-related bleeding and perforation rates were 6.3 % and 4.7 %, respectively. No recurrences were observed in patients who had undergone complete ER at a median follow-up period of 20 months (range 6-112 months). CONCLUSION: ER is an effective, safe, and feasible treatment for duodenal SETs, especially when the SET is located in the deep mucosal layer and/or the submucosal layer.

Safety and efficacy of endoscopic submucosal dissection of large (≥3 cm) subepithelial tumors located in the cardia.

BACKGROUND: Upper gastrointestinal subepithelial tumors (SETs) may harbor potential malignancy. Although it is well recognized that large SETs should be resected, the treatment strategy remains controversial. Compared to surgical resection, endoscopic resection has many advantages such as less invasive, shorter hospital stay, lower costs, and better quality of life. However, Endoscopic resection of large SETs in the cardia is challenging. The purpose of this study was to evaluate the safety and efficacy of endoscopic submucosal dissection (ESD) in the treatment of such SETs. METHODS: A total of 41 patients with large SETs (≥3 cm in diameter) located in the cardia were involved in the study. All patients underwent ESD. Data on therapeutic outcomes and follow-up were collected, for analysis of risk factors of complication rates. RESULTS: The average tumor size was 4.7 ± 1.7 cm. The average procedure time was 69.3 ± 32.7 min and the average postoperative hospital stay was 3.5 ± 1.1 days. A total of 41 tumors were removed successfully, in which 35 were leiomyomas, three were gastrointestinal stromal tumors, two were lipomas, and one was gastritis cystica profunda. The en bloc resection rate was 90.2%, and was significantly higher for tumors with a round or oval shape (100%) than for those with an irregular shape (75.0%) (P < 0.05). Five patients experienced complications (12.2%), all of which were managed conservatively. The complication rates were significantly higher in patients with a tumor originating from the deep muscularis propria layer and demonstrating a trans-cardia growth pattern. No residual or tumor recurrence was observed and no stricture occurred during the follow-up period (average, 26.7 ± 18.4 months). CONCLUSIONS: ESD is safe and effective to curatively remove most large SETs in the cardia, and may serve as an accurate histopathology measurement to direct future therapy.