Gastric Subepithelial Tumors Research Articles

Factors Associated with Operation Time of Laparoscopic Gastric Wedge Resection for Gastric Subepithelial Tumors.

PurposeGastric subepithelial tumor (GST) is a disease entity that includes all gastric subepithelial lesions. The oncologically safe surgical technique is complete resection with adequate resection margins. Most of the studies about laparoscopic gastric wedge rsection (LGWR) in GST focus on oncologic curability or surgical effectiveness. However, studies on the factors associated with the operation time are rare. Therefore, this study was conducted to analyze and compare the factors associated with the operation time of LGWR.MethodsFrom 2010 to 2019, 145 consecutive patients undergoing LGWR were reviewed retrospectively. Clinical characteristics of GST and operation time were analyzed and compared.ResultsA total of 145 patients was enrolled and reviewed. There were 59 males (40.7%) and 86 females (59.3%) with a mean age of 53.6 years and mean body mass index (BMI) of 23.9 kg/m2. Mean tumor size was 2.9 cm and mean operation time was 66.0 minutes. In statistically, the mean operation time showed significant association with tumor size, BMI, longitudinal tumor location and tumor location between lesser and greater curvature. In multivariate analysis, tumor size, BMI and longitudinal classification of tumor location are statistically significant.ConclusionA shorter operation time is expected when there is a small tumor, low BMI and mid portion of the stomach GST. Preoperative evaluation for tumor size and body weight is important. In patients with large GST, obesity and both end stomach GST, we think that pre-operative preparation for long operation time should be considered.

Su1305 A SAFE AND COST EFFECTIVE STRATEGY FOR THE MANAGEMENT OF SMALL ASYMPTOMATIC GASTRIC SUBEPITHELIAL TUMORS: A CASE SERIES

Gastric subepithelial tumors (SETs) are relatively common incidental findings encountered on endoscopy. Current ASGE guidelines for small SETs (<2cm) arising from the second and third echolayers recommend tissue acquisition for diagnosis or endoscopic mucosal resection (EMR) for lesions that are symptomatic or increase in size over time. If tissue acquisition is non-diagnostic, it is recommended that these patients have endoscopic ultrasound (EUS) surveillance at poorly defined intervals. In addition to the cumulative risk of anesthesia and significant cost of repeated endoscopy, diagnosis may be challenging because of the low diagnostic yield of tissue acquisition methods currently available for these SETs and the limited accuracy of EUS with endosonographic imaging alone. We propose that routine EMR of asymptomatic gastric SETs <2cm arising from the second and third echolayers is a safe and more cost effective strategy for management than current surveillance recommendations. Provation was queried to identify patients undergoing EUS with a coded diagnosis of “gastric nodule” or “intramural lesion” from September 2017 through September 2019 at our institution. Inclusion criteria for analysis were gastric SETs <2cm arising from the second and third echolayers and removed with EMR. These cases were reviewed for EMR-related complications and pathology of removed specimens. Of the 96 cases identified, 13 patients with 14 distinct lesions met inclusion criteria. All lesions were removed via endoscopic cap band mucosectomy. The mean age of patients was 58.6 years with a female predominance (69.2%). The mean size of these gastric SETs was 7.4 mm. Lesions were most commonly located in the gastric antrum (64%). Pancreatic heterotopia (29%), gastric mucosa (29%), and inflammatory fibroid polyps (23%) were most the most commonly reported pathologic findings. Notably, no carcinoid or other neoplastic lesions were identified. Hemostatic clips were used in 50% of removed lesions. No procedural complications such as perforation were identified. Currently available tissue acquisition methods for small gastric SETs are not always diagnostic, obligating many patients to the EUS surveillance pathway. This results in repeated procedures with a cumulative risk of adverse events. Our results are consistent with published literature showing that asymptomatic SETs <2 cm originating from the second and third echolayers are often benign and can be safely removed by EMR. The more universal use of EMR in this context would increase diagnostic yield, reduce procedural risks, and provide substantial cost savings by eliminating the need for surveillance. As evidence mounts for the safe and efficacious use of EMR in this context, updated guidelines to include this as a viable option need to be considered.

Reasons for Diagnostic Failure in Forty-Five Consecutive Mucosal Cutting Biopsy Examinations of Gastric Subepithelial Tumors.

Background/Aims:Mucosal cutting biopsy (MCB) is useful for the histopathological diagnosis of gastric subepithelial tumors (SETs). However, there is little information on cases in which MCB did not establish a diagnosis. In the current study, we aimed to investigate the characteristics of cases in which MCB was unsuccessful. Methods:Cases in which MCB was used to histopathologically diagnose gastric SETs at Kobe University Hospital between August 2012 and October 2018 were retrospectively reviewed. Results:Forty-five cases in which MCB was used to diagnose 43 gastric SETs in 43 patients were analyzed. The median tumor size was 20 mm (range, 8–50 mm). Pathological examinations resulted in definitive and suspected diagnoses and no diagnosis in 29 (gastrointestinal stromal tumor: n=17, leiomyoma: n=7, aberrant pancreas: n=3, others: n=2), 6, and 10 cases, respectively. Failure to expose the tumor according to retrospective examinations of endoscopic images was significantly associated with no diagnosis. Other possible explanations included a less elevated tumor, biopsy of the surrounding field instead of the tumor due to the mobility, and poor endoscope maneuverability due to the tumor being close to the cardia. Conclusions:Clear exposure of gastric SETs during MCB may improve the diagnostic rate of such examinations.

Wedge gastrectomy: Robot-assisted with a hand-sewn repair versus a laparoscopic linear stapler technique for gastric subepithelial tumors

ObjectiveMinimally invasive surgery has become common in surgical resections of gastric subepithelial tumors. An endostapler technique is simple and easy to perform when cutting the stomach. Gastrotomy using a hand-sewn repair is a new approach for identifying and removing gastric subepithelial tumors, but few studies have evaluated its efficacy. In this study, we demonstrated the safety and effectiveness of this novel technique using a robot-assisted approach. Materials and methodsA retrospective cohorts of all patients who presented with gastric subepithelial tumors and underwent robotic or laparoscopic resection at Ramathibodi Hospital from 2012 to 2018 was reviewed. Surgical outcomes and complications of the robot-assisted approach with a hand-sewn repair were analyzed and compared to those of the laparoscopic linear stapler technique. ResultsIn total, 25 patients were included in this study. Most of the subepithelial tumors were gastrointestinal stromal tumors (17 patients, 68%). Ten patients (40%) underwent a robot-assisted procedure with a hand-sewing technique, and 15 patients underwent a laparoscopic linear stapler procedure. Mean tumor size was 3.79 ± 1.35 cm in the robot-assisted procedure with a hand-sewing technique group and 3.52 ± 1.88 cm in the laparoscopic linear stapler procedure group. The former experienced a longer operative time (261 ± 54 vs 144 ± 64 minutes, p < 0.001) and a longer time to return to a normal diet (5.7 ± 2.0 vs 4.0 ± 1.4 days, p = 0.028). Neither group experienced perioperative complications or mortality. ConclusionAlthough the time to return to a normal diet and operative time were significantly longer compared to a laparoscopic procedure using a linear stapler, the robot-assisted approach using a hand-sewn repair for gastric subepithelial tumors is feasible, effective, and safe. This can be an alternative for the surgical treatment of gastric subepithelial lesions.

Long-term Outcomes of Endoscopic Resection for Gastric Subepithelial Tumors.

The purpose of the current study was to analyze the safety and efficacy of endoscopic resection for gastric subepithelial tumors (SETs) using long-term patient outcome data. A retrospective analysis of 73 consecutive patients with gastric SETs was performed from June 2014 to December 2016. The treatment methods included submucosal dissection, submucosal excavation or endoscopic full-thickness resection (EFTR). In addition to epidemiological data (sex and age), tumor size, surgical parameters, length of stay, complications, costs, and endoscopic, clinicopathologic, and follow-up data were analyzed to compare treatments. The complete resection rate was 97.3% (71/73). Three patients experienced complications (4.1%), including 2 with delayed perforation and 1 with perioperative infection. The median postoperative feeding time was 3 days, and the median postoperative hospital stay was 5 days. The median follow-up period was 19 months, with no patient death or tumor recurrence. Among the 38 patients with gastrointestinal stromal tumors, the complete resection rate was 97.4% (37/38). The complete resection and complication rates between the endoscopic submucosal excavation (ESE) group and the EFTR group were not statistically significant. There was no recurrence or metastasis detected among either group; however, the ESE group had earlier postoperative feeding, a shorter postoperative hospital stay, and less hospitalization expenses. Endoscopic resection for gastric SETs (<3 cm) is safe and feasible concerning medium-term and long-term effects. Compared with the EFTR group, the ESE group had earlier postoperative feeding, a shorter postoperative hospital stay, and less hospitalization expenses. Even so, gastric SETs with malignant potential are at risk of recurrence. Larger prospective multicenter studies are warranted.

A new endoscopic submucosal resection -ligation technique for gastric tumors.

Although most subepithelial lesions are benign, the malignant forms could present as serious life-threating cancers. Their accurate diagnosis depends on complete surgical resection. Different endoscopic methods have been recommended for the resection. Recently, the EMR has been considered as a safe and effective technique, while various revised EMR techniques have been introduced. In this study, a new version of EMR has been evaluated in two patients. Two middle-aged cases with gastric subepithelial tumors were admitted to Taleghani gastrointestinal department. The polyps were resected via our new Endoscopic Mucosal Resection (EMR) technique. In this technique, the needle knife was used for un-roofing the mucosal surface. Then, the polyps were resected with hot snares. The hemoclips were applied for ligation too. We found no early or delayed complications. Furthermore, the microscopic margins of the lesions were free. Our study represented a safe and cost-beneficial technique for subepithelial lesions and no complications was found and the margins were free. However, further investigations are required for confirming the validity of this new EMR technique.

Multiparametric MRI and 18F-FDG PET features for differentiating gastrointestinal stromal tumors from benign gastric subepithelial lesions.

To investigate whether multiparametric magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose positron emission tomography (PET) can be helpful in differentiating gastrointestinal stromal tumors (GISTs) from non-GISTs and high-risk GISTs from low-risk GISTs. This retrospective study included 56 patients with pathologically confirmed GISTs (n = 39), leiomyoma (n = 8), schwannoma (n = 5), heterotopic pancreas (n = 3), and glomus tumor (n = 1) who underwent MRI and/or PET examinations. Two radiologists reviewed MRI regarding location, shape, contour, growth pattern, margin, signal intensity (SI) on T1- (T1WI) and T2-weighted images (T2WI), degree and pattern of enhancement, hemorrhage, and necrosis. Mean apparent diffusion coefficient (ADC) and maximum standardized uptake value (SUVmax) were measured. Imaging features were compared among non-GISTs, low-risk GISTs, and high-risk GISTs using uni- and multivariate statistical analyses. Size, longitudinal location, shape, contour, growth pattern, SI on T1- and T2WI, enhancement pattern, hemorrhage, necrosis, ADC, and SUVmax were significantly different among non-GISTs, low-risk GISTs, and high-risk GISTs (p < 0.05). On multivariate analysis, SI on T2WI (hazard ratio [HR], 66.0; p = 0.002) was the only independent variable for differentiating GISTs from non-GISTs whereas enhancement pattern (HR, 56.0; p = 0.041), ADC (HR, 0.997; p = 0.01), and SUVmax (HR, 2.08; p = 0.027) were significant features for differentiating between high-risk and low-risk GISTs. Several qualitative and quantitative MRI and PET features including ADC and SUVmax values are significantly different among non-GISTs, low-risk GISTs, and high-risk GISTs. Multiparametric information obtained from MRI with or without PET can be useful for differentiation of gastric subepithelial tumors as well as for determining patients' management and prognosis. • Several qualitative MRI features are helpful in distinguishing gastrointestinal stromal tumors (GISTs) from non-GISTs as well as high-risk GISTs from low-risk GISTs. • Apparent diffusion coefficient value on diffusion-weighted imaging can be useful in distinguishing GISTs from non-GISTs as well as high-risk GISTs from low-risk GISTs. • PET has the potential to distinguish between high-risk and low-risk GISTs.

Diagnosis of Gastric Subepithelial Tumors Using Endoscopic Ultrasonography or Abdominopelvic Computed Tomography: Which is Better?

Diagnosis of Gastric Subepithelial Tumors Using Endoscopic Ultrasonography or Abdominopelvic Computed Tomography: Which is Better?

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

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. 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. Endoscopic resection was successfully performed in all patients. The median overall procedure time was 43.5min (range 26-106min). The mean size of resected specimens was 19.73mm (range 10-33mm). 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. 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.

A novel technique for removing large gastric subepithelial tumors with ESD method in the subcardia region.

Previously, patients with tumors larger than 4 cm in sub-cardia region usually received open gastrectomy. Due to its anatomic features, the cardia is often considered as a contraindicated area for endoscopic resection. Herein, we report a novel technique of endoscopic submucosal dissection (ESD) which facilitates the removal of gastric subepithelial tumors (SMTs) larger than 4 cm in the subcardia and fundus region. This is a retrospective case series of patients with SMTs larger than 4 cm in the subcardia and fundus regions who received the novel procedure of ESD between October 2015 and October 2016. The novel procedure of ESD involved a median linear incision of the mucosa being made in the central area of the tumor, followed by the submucosal dissection. The residual defect was finally closed using titanium endoclips. The endoscopical outcomes, histopathological findings as well as other complications were assessed. Eight patients fulfilled the entry criteria. The mean lesion size was 45.6±7.5 mm (range: 40.0–65.0 mm), and the mean operating time was 83±13 min (range: 60–100 min). The en bloc resection rate was 100%. Although perforations occurred in 5 out of 8 patients, they were successfully closed with endoclips. The median length of inpatient hospital stay was 6 days (range: 5–8 days). No patients needed further gastrectomy. The median follow-up was 36 months and none of the patients developed local recurrence or distant metastasis. The advanced procedure of ESD is feasible and safe for tumors more than 4 cm in the subcardia region. It could be applied as a novel technique for treating patient without surgical interventions.

Utility of EUS elastography in the diagnosis of gastric subepithelial tumors: a pilot study (with video)

EUS elastography is a real-time imaging technique that analyzes tissue elasticity. The aim of this study was to investigate the applicability of quantitative EUS elastography in the differential diagnosis of gastric subepithelial tumors (SETs). We prospectively registered 41 consecutive patients with gastric SETs and measured their strain ratios with EUS elastography. The strain ratios of gastric SETs were compared with the histopathologic diagnosis. Thirty-one patients (mean age, 51.4 ± 12.6 years) were included in the analysis. The mean size of the SETs was 2.3 ± 0.7 cm. Lipomas had the lowest strain ratio of 1.6 (1.1-2.0), followed by leiomyomas 6.0 (2.0-29.0), ectopic pancreas 11.8 (1.7-29.3), gastrointestinal stromal tumors (GISTs) 51.1 (29.0-67.0), and schwannomas 62.0. With a cut-off value of 22.7, EUS elastography could differentiate GISTs from leiomyomas with sensitivity and specificity of 100% and 94.1%, respectively (P= .001; 95% confidence interval, 0.979-1.000). EUS elastography could be a promising diagnostic adjunct for the assessment of gastric SETs, especially in differentiating GISTs from leiomyomas.

Laparoscopic Treatment of Gastric Subepithelial Tumor: Finding Ways to Manage with Shorter Hospitalization Days.

PurposeThe standard treatment for gastric subepithelial tumor (SET) is surgical resection, which is primarily performed via laparoscopy. The aims of this study were firstly to evaluate factors influencing morbidity and hospitalization after treatment of gastric SET, and secondly, to figure out the factors how to make shorter hospitalization with equal safety.MethodsWe retrospectively enrolled 229 consecutive patients who underwent laparoscopic gastric wedge resection (LGWR) for gastric SET between August 2003 and December 2015. Patients were divided into two groups: the 3 days or less hospitalization group (N=82, group A) and the greater than 3 days hospitalization group (N=147, group B).ResultsMedian tumor size was 3.0 cm (range, 0.2~13.0 cm) and mean postoperative hospitalization was 4.27±2.15 days. There were 6 complications (2.6%), with no cases of mortality. In group A, tumors were smaller (3.0±1.1 cm vs. 3.6±1.9 cm, p<0.01) and more likely to be located on the greater curvature (28% vs. 15%, p<0.01) compared with group B. The tumor growth pattern (exophytic tumor: 72% in group A vs. 65% in group B, p=0.25) was not different between the two groups. Multivariate analysis showed that tumor size larger than 5 cm and posterior wall tumor location were risk factors for longer hospital stay.ConclusionWe could reduce the hospitalization of patients with gastric SET less than 5cm sized and located on other than the posterior wall within 3days. Those patients could be a candidate for day surgery.

Efficacy of Endoscopic Ultrasound-Guided Fine-Needle Biopsy in Gastric Subepithelial Tumors Located in the Cardia.

In cases of subepithelial tumors (SETs) located in the cardiac area, a preoperative histologic diagnosis might be helpful in determining the requirement of surgery. To investigate the efficacy of endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) in gastric SETs located in the cardia. The data of 107 patients who underwent EUS-FNB, from 2012 to 2017, for tissue sampling of gastric SETs located in the cardia were collected. The clinicopathological data, EUS-related parameters, and surgical outcomes were retrospectively reviewed. The EUS-FNB results were diagnostic in 86.9% (93/107) and nondiagnostic in 13.1% (14/107) of the patients. Immunostaining of the FNB specimens led to the diagnosis of gastrointestinal stromal tumor (GIST) in 25 SETs (23.4%), leiomyoma in 62 SETs (57.9%), heterotopic pancreas in 3 SETs (2.8%), and schwannoma in 2 SETs (1.9%). In the multivariate analysis, patients with GISTs showed significantly more inhomogeneous echogenicity [odds ratio (OR), 8.867], more cystic foci (OR, 26.98), and older age (OR, 1.087). In 26 patients who underwent surgical resection, the agreement between EUS-FNB and surgical pathological findings was 100% with respect to the diagnosis of GISTs (n = 20) and leiomyoma (n = 7). Among these cases, the proportion of high-risk GISTs was 20.0% (4/20), and no leiomyosarcoma was detected. Although a majority of the subepithelial lesions in the cardia of the stomach are benign, 20% of the cases diagnosed with GIST have a high malignant potential. Preoperative EUS-FNB might be a useful tool for decision-making regarding the ultimate management and outcomes of these lesions.

Comparison of the Diagnostic Ability of Endoscopic Ultrasonography and Abdominopelvic Computed Tomography in the Diagnosis of Gastric Subepithelial Tumors.

Background/AimsEndoscopic ultrasonography (EUS) is the most efficient imaging modality for gastric subepithelial tumors (SETs). However, abdominopelvic computed tomography (APCT) has other advantages in evaluating the characteristics, local extension, or invasion of SETs to adjacent organs. This study aimed to compare the diagnostic ability of EUS and APCT based on surgical histopathology results. MethodsWe retrospectively reviewed data from 53 patients who underwent both EUS and APCT before laparoscopic wedge resection for gastric SETs from January 2010 to December 2017 at a single institution. On the basis of histopathology results, we assessed the diagnostic ability of the 2 tests. ResultsThe overall accuracy of EUS and APCT was 64.2% and 50.9%, respectively. In particular, the accuracy of EUS vs. APCT for the diagnosis of gastrointestinal stromal tumors (GISTs), leiomyomas, and ectopic pancreas was 83.9% vs. 74.2%, 37.5% vs. 0.0%, and 57.1% vs. 14.3%, respectively. Most of the incorrect diagnoses with EUS involved hypoechoic lesions originating in the fourth echolayer, with the most common misdiagnosed lesions being GISTs mistaken for leiomyomas and vice versa. ConclusionsAPCT showed a lower overall accuracy than EUS; however, APCT remains a useful modality for malignant/potentially malignant gastric SETs.

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

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). The RESET trial was initiated in March 2017 (NCT03096236) and designed as prospective observational multicenter pilot trial. Gastric SET up to 15mm 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). 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 3months. 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.

Video Comment on Ming-Ming Zhang et al.

Ming-Ming Zhang et al. Endoscopic ultrasound-guided needle-based confocal laser endomicroscopy for diagnosis of gastric subepithelial tumors: a pilot study

Continuing Medical Education Questions: May 2019.

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Current Status of Endoscopic Resection of Gastric Subepithelial Tumors.

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

Per oral endoscopic tumor (POET) resection for treatment of upper gastrointestinal subepithelial tumors.

Endoscopic submucosal tunneling has evolved to allow endoscopic resection of subepithelial tumors of gastrointestinal tract without full-thickness perforation. This study aimed to investigate safety and efficacy of submucosal tunnel resection for these tumors. Patients with subepithelial tumors (SET) located in esophagus, gastric cardia, lesser curvature, and antrum were recruited. The size of tumor was limited to < 40mm. The procedures were performed under general anesthesia. A mucosal entrance was created 2cm proximal to the SET after submucosal injection. Submucosal tunnel was then extended and the tumor was dissected and mobilized with intact overlying mucosa. After complete dissection, the tumors would be retrieved per orally and mucosal entrance closed by endoclips. From June 2012 to December 2016, 51 patients with subepithelial tumors received POET. 39 patients had SET in stomach, 11 located in esophagus, and 1 in duodenum. The mean operative time was 90.46 ± 46.49min, while the mean size of the tumors was 20.71 ± 14.05mm. The POET was converted to endoscopic full-thickness resection (EFTR) in three patients with gastric subepithelial tumors located at greater curvature. The overall complication rate was 4.0%, and there was no bleeding, mucosal dehiscence, or leakage. The time to resume diet was 1.7days, while the average hospital stay was 3.2 ± 1.0days. The mean follow-up period was 19 ± 16months, and only 1 patient developed recurrence of leiomyoma. Per oral endoscopic tumor resection is safe and effective treatment for esophageal and gastric SET located at cardia, lesser curvature, and antrum. Currently, POET for treatment of upper GI SET is limited by the size and location of the tumor.

Gastric sub-epithelial tumors: identification of gastrointestinal stromal tumors using CT with a practical scoring method.

To determine CT features that can identify gastrointestinal stromal tumors (GISTs) among gastric sub-epithelial tumors (SETs) and to explore a practical scoring method. Sixty-four patients with gastric SETs (51 GISTs and 13 non-GISTs) from hospital I were included for primary analyses, and 92 (67 GISTs and 25 non-GISTs) from hospital II constituted a validation cohort. Pre-operative CT images were reviewed for imaging features: lesion location, growth pattern, lesion margin, enhancement pattern, dynamic pattern, attenuation at each phasic images and presence of necrosis, superficial ulcer, calcification, and peri-lesion enlarged lymph node (LN). Clinical and CT features were compared between the two groups (GISTs versus non-GISTs) and a GIST-risk scoring method was developed; then, its performance for identifying GISTs was tested in the validation cohort. Seven clinical and CT features were significantly suggestive of GISTs rather than non-GISTs: older age (> 49years), non-cardial location, irregular margin, lower attenuation on unenhanced images (≤ 43 HU), heterogeneous enhancement, necrosis, and absence of enlarged LN (p < 0.05). At validation step, the established scoring method with cut-off score dichotomized into ≥ 4 versus < 4 for identifying GISTs revealed an AUC of 0.97 with an accuracy of 92%, a sensitivity of 100% and a negative predictive value (NPV) of 100%. Gastric GISTs have special CT and clinical features that differ from non-GISTs. With a simple and practical scoring method based on the significant features, GISTs can be accurately differentiated from non-GISTs.