BACKGROUND: The majority of esophageal subepithelial lesions originating from the muscularis propria (SEL-MPs) are benign in nature, although a subset may exhibit malignant characteristics. Conventional endoscopic resection techniques are time-consuming and lack efficacy for small SEL-MPs.
OBJECTIVE: To evaluate the efficacy and safety of ligation-assisted endoscopic submucosal resection (ESMR-L) following unroofing technique for small esophageal SEL-MPs.
METHODS: From January 2021 to September 2023, 17 patients diagnosed with esophageal SEL-MPs underwent ESMR-L following unroofing technique at the endoscopy center of Shenzhen People\'s Hospital. Details of clinicopathological characteristics and clinical outcomes were collected and analyzed.
RESULTS: The mean age of the patients was 50.12 ± 12.65 years. The mean size of the tumors was 7.47 ± 2.83 mm and all cases achieved en bloc resection successfully. The average operation time was 12.2 minutes without any complications. Histopathology identified 2 Lesions (11.8%) as gastrointestinal stromal tumors at very low risk, 12 Lesions (70.6%) as leiomyoma and 3 Lesions (17.6%) as smooth muscle proliferation. No recurrence was found during the mean follow-up duration of 14.18 ± 9.62 months.
CONCLUSIONS: ESMR-L following roofing technique is an effective and safe technique for management of esophageal SEL-MPs smaller than 20 mm, but it cannot ensure en bloc resection and may require further treatment.

UNASSIGNED: Pre-operative prediction of postoperative nausea and vomiting (PONV) is primarily based on the patient\'s medical history. The predictive value of gastric morphological parameters observed on ultrasonography has not been comprehensively assessed.
UNASSIGNED: A prospective observational study was conducted to evaluate the pre-operative ultrasonographic measurement of gastric morphology for predicting PONV. The gastric antrum of the participants was assessed using ultrasound before anesthesia, and the occurrence of PONV in the first 6 hours and during the 6-24 hours after surgery was reported. The main indicators included the thickness of the muscularis propria (TMP) and the cross-sectional area of the inner side of the muscularis propria (CSA-ISMP). These were recorded and analyzed. Logistic regression analysis was applied to identify factors for PONV.
UNASSIGNED: A total of 72 patients scheduled for elective gynecological laparoscopic surgery were investigated in the study. The pre-operative CSA-ISMP of patients with PONV in the first 6 hours was significantly greater than that of those without PONV (2.765 ± 0.865 cm² vs 2.349 ± 0.881 cm², P=0.0308), with an area under the curve of 0.648 (95% CI, 0.518 to 0.778, P=0.031). Conversely, the pre-operative TMP of patients with PONV during the 6-24 hours was significantly smaller than that of those without PONV (1.530 ± 0.473 mm vs 2.038 ± 0.707 mm, P=0.0021), with an area under the curve of 0.722 (95% CI, 0.602 to 0.842, P=0.003). Logistic regression analysis confirmed that CSA-ISMP was an independent risk factor for PONV in the first 6 hours (OR=2.986, P=0.038), and TMP was an independent protective factor for PONV during the 6-24 hours after surgery (OR=0.115, P=0.006).
UNASSIGNED: Patients with a larger pre-operative CSA-ISMP or a thinner TMP are prone to develop PONV in the first 6 hours or during the 6-24 hours after surgery, respectively.
UNASSIGNED: http://www.chictr.org.cn (ChiCTR2100055068).

Background & Objective: Assessment of muscularis propria invasion is a crucial step in the management of urothelial carcinoma since it necessitates aggressive treatment. The diagnosis of muscle invasion is a challenging process for pathologists. Artificial intelligence is developing rapidly and being implemented in various fields of pathology. The purpose of this study was to develop an algorithm for the detection of muscularis propria invasion in urothelial carcinoma. Methods: The Training cohort consisted of 925 images from 50 specimens of urothelial carcinoma. Ninety-seven images from 10 new specimens were used as a validation cohort. Clinical validation used 127 whole specimens with a total of 617 slides. The algorithm determined areas where tumor and muscularis propria events were in nearest proximity, and presented these areas to the pathologist. Results: Analytical evaluation showed a sensitivity of 72% for muscularis propria and 65% for tumor, and a specificity of 46% and 77% for muscularis propria and tumor detection, respectively. The incorporation of the spatial proximity factor between muscularis propria and tumor in the clinical validation significantly improved the detection of muscularis propria invasion, as the algorithm managed to identify all except for one case with muscle invasive bladder cancer in the clinical validation cohort. The case missed by the algorithm was nested urothelial carcinoma, a rare subtype with unusual morphologic features. The pathologist managed to identify muscle invasion based on the images provided by the algorithm in a short time, with an average of approximately 5 s. Conclusion: The algorithm we developed may greatly aid in accurate identification of muscularis propria invasion by imitating the thought process of the pathologist.

Detrusor muscle (DM) in the resected specimen of patients with pT1 bladder cancer (BCa) is a quality-of-care criteria. We aimed to assess whether obtaining adequate DM is dependent on surgeon\'s experience, whether is a surrogate for resection quality, and whether the degree of DM thickness is related to postoperative outcomes in en bloc resection for bladder tumors (ERBT).
We retrospectively analyzed the records of 106 pT1 high-grade BCa patients who underwent ERBT at several institutions. All specimens were reviewed by a single pathologist who assessed the presence or absence of DM and its thickness measured by a micrometer, when present. Early recurrence, defined as pathologically confirmed BCa on repeat resection or tumor recurrence at the first follow-up cystoscopy (within 3 months), was the endpoint reflective of the resection quality.
Of 106 patients, DM was detected in 99 (93%), and the median DM thickness was 1.8 mm. Large tumor size (>30 mm) was associated with adequate DM sampling (>1.8mm) (odds ratio [OR]: 6.10, 95% confidence intervals [CIs]: 2.08-17.9, P = 0.001), while surgeon\'s experience was not. DM presence and DM thickness were both not associated with early recurrence, while positive surgical margin was an independent prognosticator for early recurrence (OR: 3.38, 95% CI: 1.12-10.2, P = 0.031). Excessive DM sampling (>2.1 mm) was associated with prolonged urethral catheterization (OR: 28.8, 95% CI: 3.36-248, P = 0.002).
In ERBT, surgeon\'s experience seems irrelevant to obtain DM. Resection quality relies on surgical margin status, not the degree of DM. Obtaining excessive DM incurs adverse events/unnecessary medical care.

BACKGROUND: Endoscopic resection (ER) is a proven treatment for gastric gastrointestinal stromal tumors (gGISTs). We aimed to assess the learning curve (LC) associated with ER for gGISTs and identify determinants.
METHODS: We conducted an analysis of 289 patients who underwent the ER of gGISTs by an experienced endoscopist. To characterize the LC, we employed cumulative sum analysis of the duration of surgery. The participants were divided into an early phase (cases 1-50) and a later phase (case 51-289), which were compared. Furthermore, we identified risk factors for the conversion from endoscopic to laparoscopic resection (LR).
RESULTS: The durations of surgery and hospitalization were shorter, and there were fewer complications and fasting days in the later phase. The conversion rates to LR were 6.0% and 2.5% in the early and later phases, respectively. The tumor diameter (≥3.0 cm) and invasion beyond the muscularis propria were significant risk factors for conversion to LR (odds ratio 17.92, 95% confidence interval 2.66-120.87; and 58.03, 6.40-525.84; respectively).
CONCLUSIONS: The LC for ER of gGISTs lasts for approximately 50 cases. In addition, tumors ≥3.0 cm in diameter and those that invade beyond the muscularis propria are more likely to require conversion to LR.

UNASSIGNED: The fundus of the stomach is a challenging region for endoscopic resection of gastrointestinal stromal tumors (GISTs), especially in the anterior wall of the fornix at the side of the greater curvature. This study aimed to introduce the Forward-Return Way (FRW) technique in gastric fundus operations and provide evidence of its advantages. The FRW technique allows the gastroscope to access the stomach fornix without entering the gastric antrum after passing through the gastric cardia. Using FRW, the gastroscope body makes a forward return along the wall of the posterior wall of the upper gastric body and the wall of the greater curvature.
UNASSIGNED: The clinical data of patients with stromal tumors in muscularis propria at the gastric fundus (STMF) at the Fourth Hospital of China Medical University between May 2020- March 2021 were reviewed. The novel FRW technique was used in the procedures, and the beneficial effects, suitability, applicable lesion site, and success rates of FRW were analyzed.
UNASSIGNED: A total of 10 cases were reviewed, and the FRW technique was successfully performed in 7 cases (70%). The gastroscope\'s tip reached the area just below the gastric cardia, allowing endoscopists to successfully access all angles and sites of the stomach\'s fundus in all seven patients. The lesion was easily accessed, and the gastroscope was stable with good left-right and forward-backwards movements.
UNASSIGNED: The FRW technique significantly facilitates the resection of the GISTs by aligning the endoscopy body movement direction with the observation direction. Gastrointestinal Stromal Tumor; forward-return of gastroscopy along the gastric body wall; muscularis propria; gastric fundus.

We compared endoscopic \"calabash\" ligation and resection (ECLR) and endoscopic submucosal excision (ESE) in treating endophytic gastric stromal tumors (GSTs) ≤15 mm in diameter originating from the muscularis propria.
We performed a retrospective study and included patients who visited our hospital for removal of small endophytic GSTs (diameter ≤ 15 mm) confirmed by postoperative pathological reports between February 2019 and December 2020. Patients were assigned to the study (received ECLR) or control (accepted ESE) groups, and their medical records were reviewed. Age, sex, GST size, resection outcomes, procedure measurements, lengths of hospital stays, medical expenses, intraoperative and postoperative complications, and follow-up outcomes were documented and compared between the two groups. Propensity score matching was used to avoid retrospective biases.
A total of 277 patients were included in the analysis, with 135 in the study group and 142 in the control group. After propensity score matching, 119 cases in each group were finally included in the study. Compared to the control group, the study group had significantly shorter procedure durations and lengths of hospital stays, as well as reduced medical expenses. Compared to the control group, the study group also had significantly lower incidence rates of intraoperative stomach perforation, postoperative intraperitoneal infection, and postoperative electrocoagulation syndrome, as well as a lower intensity of postoperative pain. There were no significant differences in the other measurements between the two groups.
ECLR is an effective and safe procedure for treating patients with endophytic GSTs ≤15 mm in diameter originating from the muscularis propria.

OBJECTIVE: Models for predicting perforation during endoscopic resection (ER) of gastric submucosal tumors (SMTs) originating from the muscularis propria (MP) are rare. Therefore, this study was conducted to determine important parameters in endoscopic ultrasonography (EUS) images to predict perforation and to build predictive models.
METHODS: Consecutive patients with gastric SMTs originating from the MP who received ER from May 1, 2013 to January 15, 2021 were retrospectively reviewed. They were classified into case and control groups based on the presence of perforation. Logistic multivariate analysis was used to identify potential variables and build predictive models (models 1 and 2: with and without information on tumor pathology, respectively).
RESULTS: In total, 199 EUS procedures (194 patients) were finally chosen, with 99 procedures in the case group and 100 in the control group. The ratio of the inner distance to the outer distance (I/O ratio) was significantly larger in the case group than in the control group (median ratio, 2.20 vs. 1.53; P<0.001). Multivariate analysis showed that age (odds ratio [OR], 1.036 in model 1; OR, 1.046 in model 2), the I/O ratio (OR, 2.731 in model 1; OR, 2.372 in model 2), and the pathology of the tumors (OR, 10.977 for gastrointestinal stromal tumors; OR, 15.051 for others in model 1) were risk factors for perforation. The two models to predict perforation had areas under the curve of 0.836 (model 1) and 0.755 (model 2).
CONCLUSIONS: EUS was useful in predicting perforation in ER for gastric SMTs originating from the MP. Two predictive models were developed.

Interpreting small biopsy specimens or fine-needle aspirations of gastrointestinal tract (GI) smooth muscle lesions may be challenging when the differential diagnosis includes leiomyoma vs muscularis propria (MP). We evaluated the utility of S100 staining in distinguishing GI leiomyomas from MP.
A search was conducted in our laboratory information system for cases of leiomyomas arising within the GI tract (2004-2021). Site-matched controls containing MP were selected (2018-2020). Five high-power fields (hpf) were counted on S100 immunohistochemical stains by two pathologists in the resections and by three different blinded pathologists in the biopsy specimens and analyzed.
The median S100 count was 2.5/5 hpf in leiomyoma resection cases (n = 38), which was significantly lower than the median count of 548/5 hpf in MP (n = 19) with a P value of <.0001. The median S100 count in biopsy specimens (n = 16) was 1.2/5 hpf and within the expected range of 1 to 104/5 hpf (minimum-maximum value) established by the leiomyoma resections. S100 counts in the normal MP were significantly higher than those observed in leiomyomas (P < .001).
S100 staining can aid in distinguishing a leiomyoma from MP in the GI tract, which is especially helpful when evaluating cases with limited sampling.

BACKGROUND: Endoscopic resection approaches, including endoscopic submucosal dissection (ESD), submucosal tunneling endoscopic resection (STER) and endoscopic full-thickness resection (EFTR), have been widely used for the treatment of submucosal tumors (SMTs) located in the upper gastrointestinal tract. However, compared to SMTs located in the esophagus or stomach, endoscopic resection of SMTs from the esophagogastric junction (EGJ) is much more difficult because of the sharp angle and narrow lumen of the EGJ. SMTs originating from the muscularis propria (MP) in the EGJ, especially those that grow extraluminally and adhere closely to the serosa, make endoscopic resection even more difficult.
OBJECTIVE: To investigate the predictors of difficult endoscopic resection for SMTs from the MP layer at the EGJ.
METHODS: A total of 90 patients with SMTs from the MP layer at the EGJ were included in the present study. The difficulty of endoscopic resection was defined as a long procedure time, failure of en bloc resection and intraoperative bleeding. Clinicopathological, endoscopic and follow-up data were collected and analyzed. Statistical analysis of independent risks for piecemeal resection, long operative time, and intraoperative bleeding were assessed using univariate and multivariate analyses.
RESULTS: According to the location and growth pattern of the tumor, 44 patients underwent STER, 14 patients underwent EFTR, and the remaining 32 patients received a standard ESD procedure. The tumor size was 20.0 mm (range 5.0-100.0 mm). Fourty-seven out of 90 lesions (52.2%) were regularly shaped. The overall en bloc resection rate was 84.4%. The operation time was 43 min (range 16-126 min). The intraoperative bleeding rate was 18.9%. There were no adverse events that required therapeutic intervention during or after the procedures. The surgical approach had no significant correlation with en bloc resection, long operative time or intraoperative bleeding. Large tumor size (≥ 30 mm) and irregular tumor shape were independent predictors for piecemeal resection (OR: 7.346, P = 0.032 and OR: 18.004, P = 0.029, respectively), long operative time (≥ 60 min) (OR: 47.330, P = 0.000 and OR: 6.863, P = 0.034, respectively) and intraoperative bleeding (OR: 20.631, P = 0.002 and OR: 19.020, P = 0.021, respectively).
CONCLUSIONS: Endoscopic resection is an effective treatment for SMTs in the MP layer at the EGJ. Tumors with large size and irregular shape were independent predictors for difficult endoscopic resection.