Combined endoscopic mucosal resection and full-thickness resection for large colorectal polyps: a systematic review and meta-analysis.

BACKGROUND AND AIMS: Combined endoscopic mucosal resection (EMR) with endoscopic Full thickness resection (EFTR) is an emerging technique that has been developed to target colorectal polyps larger than 2 cm. We performed a systematic review and meta-analysis to evaluate this technique for the resection of large colorectal lesions. METHODS: We conducted a comprehensive search of multiple electronic databases from inception through August 2023, to identify studies that reported on hybrid FTR. A random-effects model was employed to calculate the overall pooled technical success, macroscopic complete resection, free vertical margins resection rate, adverse events, and recurrence on follow up. RESULTS: A total of 8 Study arms with 244 patients (30% women) were included in the analysis. The pooled technical success rate was 97% (95% CI 88%-100%, I2 = 79.93%). The pooled rate of macroscopic complete resection was achieved in 95% (95% CI 90%-99%, I2 = 49.98) with a free vertical margins resection rate 88% (95% CI, 78%-96%, I2 = 63.32). The overall adverse events rate was 2% (95% CI 0%-5%, I2 = 11.64) and recurrence rate of 6% (95% CI 2%-12%, I2=20.32). CONCLUSION: Combined EMR with EFTR is effective and safe for resecting large, and complex colorectal adenomas, offering a good alternative for high surgical risk patients. Regional heterogeneity was observed, indicating that outcomes may be impacted by differences in operator expertise and industry training certification across regions. Comparative studies that directly compare combined EMR with EFTR against alternative methods such as ESD and surgical resection are needed.

Endoscopic mucosal resection and endoscopic submucosal dissection with an external additional working channel (EMR+ and ESD+) are equivalent to using a double-channel endoscope: a systematic evaluation in a porcine ex vivo model.

BACKGROUND AND AIMS: With an external additional working channel (AWC) endoscopic mucosal resection (EMR) as well as endoscopic submucosal dissection (ESD) can be extended to techniques termed "EMR+" and "ESD+." These novel techniques are systematically compared to EMR and ESD under the use of a double-channel endoscope (DC). METHODS: Our trial was conducted prospectively in a pre-clinical porcine animal model (EASIE-R simulator) with standardized gastric lesions measuring 3 or 4 cm. RESULTS: EMR+ and EMR DC showed both good results for 3 cm lesions with no adverse events and an en bloc resection rate of 73.33% (EMR+) and 60.00% (EMR DC, p = 0.70). They came to their limits in 4 cm lesions with muscularis damages of 20.00% (EMR+), 13.33% (EMR DC, p ≥ 0.99) and decreasing en bloc resection rates of 60.00% (EMR+) and 46.67% (EMR DC, p = 0.72). ESD+ and ESD DC were both reliable concerning en bloc resection rates (100% in all groups) and adverse events (0.00% in 3 cm lesions, 12.50% muscularis damages in both ESD+ and ESD DC in 4 cm lesions). Resection time was slightly shorter in all groups with the AWC compared to DC although only reaching significance in 3 cm ESD lesions (p < 0.05*). CONCLUSIONS: With the AWC, a standard endoscope can easily be transformed to double-channel functionality. We could show that EMR+ and ESD+ are non-inferior to EMR and ESD under the use of a double-channel endoscope. Consequently, the AWC presents an affordable alternative to a double-channel endoscope for both EMR and ESD.

Endoscopic submucosal dissection with an additional working channel (ESD+): a novel technique to improve procedure time and safety of ESD.

BACKGROUND AND AIMS: A new external additional working channel (AWC) was recently introduced by which endoscopic submucosal dissection (ESD) can be converted to a technique termed "ESD+ ". We aim to systematically evaluate this novel technique in flat gastric lesions and compare it to classical ESD. METHODS: The study was prospectively conducted in a pre-clinical ex vivo animal model (EASIE-R simulator) with porcine stomachs. Prior to intervention, we set standardized lesions measuring 3 cm or 4 cm in antegrade as well as in retrograde positions. RESULTS: Overall, 64 procedures were performed by an experienced endoscopist. Both techniques were reliable and showed en bloc resection rates of 100%. Overall, ESD+ reduced time of procedure compared to ESD (24.5 vs. 32.5 min, p = 0.025*). Particularly, ESD+ was significantly faster in retrograde lesions with a median of 22.5 vs. 34.0 min in 3 cm retrograde lesions (p = 0.002*) and 34.5 vs. 41.0 min (p = 0.011*) in 4 cm retrograde lesions. There were 0 perforations with both techniques. In ESD+ , 1 muscularis damage occurred (3.13%) compared to 6 muscularis damages with ESD (18.75%, p = 0.045*). CONCLUSIONS: By its grasp-and-mobilize technique, ESD+ allows potentially faster and safer resections of flat gastric lesions compared to conventional ESD in an ex vivo porcine model. The potential advantages of ESD+ in terms of procedure time may be particularly relevant for difficult lesions in retrograde positions.

EMR + with the AWC improves endoscopic resection speed compared to ESD: a porcine ex-vivo pilot study.

INTRODUCTION: To improve resection speed and to reach higher en bloc resection rates in lesions ≥ 2 cm, a novel grasp and snare EMR technique termed "EMR+", accomplished by an additional working channel (AWC), was developed. Its use compared to endoscopic submucosal dissection (ESD) is evaluated for the first time. MATERIAL AND METHODS: We prospectively conducted a randomized pre-clinical ex-vivo pilot study in explanted porcine stomachs for the comparison of EMR + with classical ESD of mucosal-based lesions. Prior to intervention, we set flat lesions with a standardized size of 3 × 3 cm. RESULTS: The median time of procedure was significantly shorter in the EMR + group (median 10.5 min, range 4.4-24 min) than in the ESD group (median 32 min, range 14-61.6 min, p < .0001). The rate of en bloc resection was significantly lower in the EMR + group (38 % vs. 95 %) (p < .0001). Nevertheless, an improvement in the learning curve for EMR + was achieved after the first 12 procedures, with a subsequent en bloc resection rate of 100 %. CONCLUSIONS: EMR + could improve the efficiency of mucosal resection procedures. Initial experience demonstrates a higher and satisfactory en bloc resection rate after going through the learning curve of EMR+.

Novel modified endoscopic mucosal resection of large GI lesions (> 20 mm) using an external additional working channel (AWC) may improve R0 resection rate: initial clinical experience.

BACKGROUND: En-bloc resection of large, flat dysplastic mucosal lesions of the luminal GI tract can be challenging. In order to improve the efficacy of resection for lesions ≥2 cm and to optimize R0 resection rates of lesions suspected of harboring high-grade dysplasia or early adenocarcinoma, a novel grasp and snare EMR technique utilizing a novel over the scope additional accessory channel, termed EMR Plus (EMR+), was developed. The aim of this pilot study is to describe the early safety and efficacy data from the first in human clinical cases. METHODS: A novel external over-the-scope additional working channel (AWC) (Ovesco, Tuebingen, Germany) was utilized for the EMR+ procedure, allowing a second endoscopic device to be used through the AWC while using otherwise standard endoscopic equipment. The EMR+ technique allows tissue retraction and a degree of triangulation during endoscopic resection. We performed EMR+ procedure in 6 patients between 02/2018-12/2018 for lesions in the upper and lower GI tract. RESULTS: The EMR+ technique utilizing the AWC was performed successfully in 6 resection procedures of the upper and/or lower GI tract in 6 patients in 2 endoscopy centers. All resections were performed successfully with the EMR+ technique, all achieving an R0 resection. No severe adverse events occurred in any of the procedures. CONCLUSIONS: The EMR+ technique, utilizing an additional working channel, had an acceptable safety and efficacy profile in this preliminary study demonstrating it's first use in humans. This technique may allow an additional option to providers to remove complex, large mucosal-based lesions in the GI tract using standard endoscopic equipment and a novel AWC device.

Endoscopic Treatment of Early-Stage Esophageal Cancer.

PURPOSE OF REVIEW: Esophageal cancer is a leading cause of global cancer-related mortality. Here, we discuss the major endoscopic treatment modalities for management of early esophageal cancer (EEC). RECENT FINDINGS: Advances in endoscopic imaging and therapy have shifted the paradigm of managing early esophageal cancers. Though esophagectomy remains the preferred management for advanced cancers, guidelines now recommend endoscopic resection followed by ablative therapy for early (Tis and T1a) cancers. Available data suggests endoscopic treatment is comparable to surgery with regard to overall and cancer-specific survival with lower procedural morbidity and mortality. Endoscopic modalities are emerging as frontline treatment options for patients with early esophageal cancers. Accurate clinical staging with assessment of disease extent, tumor grade, and risk of nodal metastases is crucial when determining eligibility for endoscopic management of EEC. High-quality routine surveillance endoscopy is critical in patients who have undergone resection and/or ablation.

High incidence of metachronous advanced adenoma and cancer after endoscopic resection of colon polyps ≥20 mm in size.

BACKGROUND AND AIM: There are limited studies on incidence rates of metachronous neoplastic lesions after resecting large colorectal polyps. In the present study, we analyzed metachronous lesions after endoscopic resection of colorectal polyps ≥20 mm in size. METHODS: We retrospectively analyzed consecutive patients who underwent endoscopic resection of polyps from 2006 to 2013 at two affiliated hospitals. All patients underwent at least two total colonoscopies before follow up to ensure minimal missed polyps. Only patients who had follow-up colonoscopy annually after resection were recruited. We separated patients according to size of polyp resected; there were 239 patients in the ≥20-mm group and 330 patients in the <20-mm group. Clinical characteristics and cumulative rates of metachronous advanced adenoma and cancer in both groups were analyzed. Advanced adenoma was defined as a neoplastic lesion ≥10 mm in size and adenoma with a villous component. RESULTS: Cumulative rate of development of metachronous advanced adenoma and cancer in the ≥20-mm group was significantly higher than in the <20-mm group (22.9% vs. 9.5%, P < 0.001) at 36 months. There was also more development of small polyps 5-9 mm in the ≥20-mm group than in the <20-mm group (45.2% vs. 28.8%, P < 0.001). With respect to metachronous lesions, there were more right-sided colonic lesions in the ≥20-mm group than in the <20-mm group (78.8% vs. 50.0%, P = 0.015). CONCLUSION: High incidence rates of development of metachronous neoplastic lesions were detected after resection of colorectal polyps ≥20 mm in size.

Endoluminal loco-regional resection by TEM after R1 endoscopic removal or recurrence of rectal tumors.

PURPOSE: The aim of this study is to evaluate the safety and efficacy of endoluminal loco-regional resection (ELRR) by transanal endoscopic microsurgery (TEM) after R1 endoscopic resection or local recurrence of early rectal cancer after operative endoscopy. MATERIAL AND METHODS: Twenty patients with early rectal cancer were enrolled, including patients with incomplete endoscopic resection, or complete endoscopic resection of a tumor with unfavorable prognostic factors (group A, ten patients), and local recurrence after endoscopic removal (group B, ten patients). At admission, histology after endoscopic polypectomy was: TisR1(4), T1R0G3(1), T1R1(5) in group A, and TisR0(8), T1R0(2) in group B. All patients underwent ELRR by TEM with nucleotide-guided mesorectal excision (NGME). RESULTS: Mean operative time was 150 minutes. Complications occurred in two patients (10%). Definitive histology was: moderate dysplasia(4), pT0N0(3), pTisN0(5), pT1N0(6), pT2N0(2). Mean number of lymph-nodes was 3.1. Mean follow-up was 79.5 months. All patients are alive and disease-free. CONCLUSIONS: ELRR by TEM after R1 endoscopic resection of early rectal cancer or for local recurrence after operative endoscopy is safe and effective. It may be considered as a diagnostic procedure, as well as a curative treatment option, instead of a more invasive TME.

Utility of a new reusable clip device for endoscopic treatment.

BACKGROUND AND AIM: Existing reusable endoscopic clip devices have some problems regarding opening the device and precise control of clip application. The aim of the present study was to evaluate reusable clip devices for endoscopic treatment. METHODS: Ability to close a large defect and grip force were evaluated using ex-vivo porcine colon. We assessed clip loading and opening in a non-clinical setting and describe the resulting learning curve. To evaluate clinical utility, data for clip application in 72 post-endoscopic mucosal resection (EMR) defects in 40 patients were retrospectively analyzed. RESULTS: There was no difference in the ability to close a 20-mm full-thickness defect and the grip force comparing the new clip device (ZEOCLIP®) and a previously used reusable clip device (EZClip®). Although the time to load the ZEOCLIP was almost same as the EZClip, the time to open the ZEOCLIP was significantly shorter than the EZClip (P < 0.001). Opening width of the ZEOCLIP was significantly wider than the EZClip (P < 0.05). We successfully accomplished closure of post-EMR defects by clip application in 72 lesions using ZEOCLIP. Reopening/repositioning and restoring it to the working channel were more frequently carried out in a non-easy location than in an easy location (11/35 [31%] vs 4/37 [11%], P = 0.030; and 21/35 [60%] vs 1/37 [3%], P < 0.001, respectively). CONCLUSIONS: ZEOCLIP is more quickly and easily opened to its maximum width compared with EZClip, and is feasible for clip application after EMR.

JGES guidelines for colorectal endoscopic submucosal dissection/endoscopic mucosal resection.

Colorectal endoscopic submucosal dissection (ESD) has become common in recent years. Suitable lesions for endoscopic treatment include not only early colorectal carcinomas but also many types of precarcinomatous adenomas. It is important to establish practical guidelines in which the preoperative diagnosis of colorectal neoplasia and the selection of endoscopic treatment procedures are properly outlined, and to ensure that the actual endoscopic treatment is useful and safe in general hospitals when carried out in accordance with the guidelines. In cooperation with the Japanese Society for Cancer of the Colon and Rectum, the Japanese Society of Coloproctology, and the Japanese Society of Gastroenterology, the Japan Gastroenterological Endoscopy Society has recently compiled a set of colorectal ESD/endoscopic mucosal resection (EMR) guidelines using evidence-based methods. The guidelines focus on the diagnostic and therapeutic strategies and caveat before, during, and after ESD/EMR and, in this regard, exclude the specific procedures, types and proper use of instruments, devices, and drugs. Although eight areas, ranging from indication to pathology, were originally planned for inclusion in these guidelines, evidence was scarce in each area. Therefore, grades of recommendation were determined largely through expert consensus in these areas.

Polysaccharide hemostatic system for hemostasis management in colorectal endoscopic mucosal resection.

BACKGROUND: A new polysaccharide hemostatic system (EndoClot(TM) ) was recently developed for bleeding control in gastrointestinal tract endoscopy; however, its efficacy and safety is not yet well established in colorectal endoscopic mucosal resection (EMR). The aim of the present study was to observe the bleeding control effect after EMR in the colorectum. PATIENTS AND METHODS: EndoClot(TM) was applied immediately to mucosal defects after resection whether or not there was post-resection bleeding. Bleeding was monitored post-procedurally by clinical findings including positive stool occult blood test and by second-look endoscopy. Hemostasis, rebleeding rates and treatment-related complications were observed. RESULTS: In total, 82 patients were enrolled, totaling 181 lesions. Among them, 20 lesions in 18 cases showed bleeding immediately after the procedure. Among them, two lesions were treated by combined hot biopsy forceps, and complete hemostasis was achieved in all cases without surgery. It took 1.1 min (0.4-2.1) tocarry out hemostasis treatment. Rebleeding with positive stool test and colonoscopy recurred in three of 18 patients with immediate post-procedural bleeding. In patients without immediate post-procedural bleeding, three patients were confirmed with delayed bleeding. No major adverse events of treatment or procedure-related serious adverse events were reported during a 30-day follow up. Colonoscopy was done in selected patients at 30 days and full recovery of mucosal defect was achieved in all cases. CONCLUSION: Polysaccharide hemostatic system effectively achieves hemostasis in controlling and preventing EMR-related bleeding with the advantage of simple application; thus it might be a useful alternative in treating bleeding endoscopically.

Endoscopic mucosal resection of a rectal malakoplakia in a healthy adult.

Malakoplakia in the gastrointestinal tract is rare in healthy young people without underlying disease. Sufficient tissue is required for accurate diagnosis. We describe a malakoplakia that developed in a healthy young woman and was treated by endoscopic mucosal resection (EMR). A 40-year-old woman with a history of taking oral contraceptives until one year earlier was referred to our hospital with anal bleeding and constipation. A colonoscopy carried out at our another hospital 18 months earlier disclosed no abnormal findings. Colonoscopy at presentation revealed a yellowish-white tumor, 5 mm in diameter, in the rectum. The lesion was slightly protruded and had a smooth flat surface, without erosion or ulceration. EMR was carried out for a definitive diagnosis. Histopathological examination showed that the tumor contained granular histiocytes, positive for CD68 and negative forcytokeratin (AE1/AE3). Several histiocytes contained intracytoplasmic round bodies (Michaelis-Gutmann bodies), which reacted positively with periodic acid-Schiff and calcium (Von Kossa) stains. Intracytoplasmic Escherichia coli (von Hansemann bodies) were identified by Giemsa staining. Based on these results, the tumor in the rectum was diagnosed as a malakoplakia. Following EMR, the patient did not receive further treatment for malakoplakia because she had no symptoms associated with malakoplakia. She has been well for more than 9 months, with no symptoms of disease. Awareness of colorectal malakoplakia is important in patients taking steroids, including oral contraceptives.

Endoscopic resection yields reliable outcomes for small rectal neuroendocrine tumors.

BACKGROUND AND AIM: We analyzed the characteristics of gastrointestinal neuroendocrine tumors and examined the outcomes and safety of modalities in rectal neuroendocrine tumors. METHODS: Between 2007 and 2011, a total of 91 patients with gastrointestinal neuroendocrine tumors were retrospectively reviewed in terms of the characteristics of tumors. RESULTS: Sixty-six patients had rectal neuroendocrine tumors and underwent endoscopic mucosal resection (EMR, n = 29), endoscopic submucosal dissection (ESD, n = 23), or transanal endoscopic microsurgery (TEM, n = 14). The complete resection rate was higher in the ESD group (82.7%) and in the TEM group (100%) compared to the EMR group (65.5%) (P < 0.046). The complication rate was higher in the ESD group (47.8%) than in the EMR group (18.5%) (P = 0.003). No local tumor recurrence was observed in all patients, regardless of the procedure, during the median follow-up period of 21.5 ± 13.5 months. CONCLUSIONS: ESD achieved a higher complete resection rate than EMR and comparable to TEM. Tumor recurrence was not observed in the endoscopic resection and TEM groups, regardless of the completeness of resection. Small neuroendocrine tumors of the gastrointestinal tract can be managed reliably with both endoscopic resection and TEM.

Delayed perforation: a hazardous complication of endoscopic resection for non-ampullary duodenal neoplasm.

BACKGROUND: Perforation is a major complication of endoscopic resection for gastrointestinal neoplasms. However, little is known about delayed perforation after endoscopic resection for non-ampullary duodenal neoplasm. The aim of the present study was to investigate the clinical features of delayed perforation after endoscopic resection for non-ampullary duodenal neoplasm. PATIENTS AND METHODS: This was a retrospective cohort study conducted in a referral cancer center. A total of 63 patients (41 with adenomas and 22 with carcinomas) underwent endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) from January 1993 to December 2011. Incidence, outcome, and factors associated with occurrence of delayed perforation were investigated. RESULTS: Delayed perforation occurred in four patients (6.3%). All lesions were located distal to Vater's ampulla. Three of four delayed perforations occurred within 36 h after endoscopic resection. All patients developed retroperitonitis, and two also had retroperitoneal abscesses. Although three patients were cured with conservative management, a long hospital stay was required (28-, 80-, and 81-day hospital stay, respectively). One patient required emergency surgery as a result of panperitonitis. There was, fortunately, no mortality in this series. The significant predictors of delayed perforation were location (distal to Vater's ampulla, P = 0.007) and resection method (ESD and piecemeal EMR, P = 0.003). CONCLUSION: Endoscopic resection for non-ampullary duodenal neoplasms has a possible risk of morbid complication i.e. delayed perforation, especially in patients with lesions located on the side distal from the ampulla and who are treated with piecemeal EMR or ESD.

Diagnostic algorithm of magnifying endoscopy with narrow band imaging for superficial non-ampullary duodenal epithelial tumors.

BACKGROUND AND AIM: A novel diagnostic algorithm for magnifying endoscopy with narrow band imaging (ME-NBI) for superficial non-ampullary duodenal epithelial tumors (SNADET) is needed because of diagnostic difficulties. METHODS: In the present study, ME-NBI images taken prior to endoscopic treatment were retrospectively analyzed to investigate the relationship between ME-NBI findings and pathological findings. Lesions displaying a single surface pattern were classified as monotype, and those displaying multiple surface patterns as mixed type. Surface pattern was classified as preserved, micrified, or absent. In addition, vascular pattern was classified as absent, network, intrastructural vascular (ISV), or unclassified. RESULTS: According to the revised Vienna classification, 100% (23/23) of mixed-type lesions were category 4/5 tumors, whereas approximately 50% (10/23) of monotype lesions were category 3 tumors. In the monotype lesions, the probability of category 4/5 tumor was 100% (2/2) in lesions with an unclassified vascular pattern, 64.3% (9/14) in lesions with an ISV pattern, 33.3% (1/3) in lesions with an absent pattern, and 25.0% (1/4) in lesions with a network pattern. CONCLUSION: These findings suggest the possibility of developing an effective diagnostic algorithm for ME-NBI for SNADET by determining their surface pattern and vascular pattern.

Therapeutic outcomes of endoscopic resection for superficial non-ampullary duodenal tumor.

BACKGROUND AND AIM: Endoscopic resection (ER) is widely used as a minimally invasive therapy to remove superficial non-ampullary duodenal tumor (SNADT). However, the indication criteria have not yet been clearly determined. At our institute, ER is done only for SNADT measuring ≤ 20 mm. We report our findings on the therapeutic outcomes of ER of SNADT. METHODS: We carried out ER in 47 patients with SNADT. Indication criteria for ER included a lesion suspected as high-grade dysplasia or mucosal cancer and measuring ≤ 20 mm. The ER methods used to carry out en bloc resection were endoscopic mucosal resection (EMR: 17 lesions) or endoscopic submucosal dissection (ESD: 30 lesions). We then analyzed the therapeutic outcomes between them. RESULTS: There were no significant differences between the EMR and ESD groups with regard to age, sex, location of the lesion, and histology. The most frequent gross types resected by EMR and ESD were 0-IIa and 0-IIc, respectively (P=0.004). Median procedure time was significantly longer in ESD than in EMR, 79.5 and 9 min, respectively (P<0.001). R0 resection was achieved in 10 cases by EMR (59%) and in 27 cases by ESD (90%) (P=0.017). No complications occurred in cases that underwent EMR, but immediate and delayed perforations occurred in three patients who underwent ESD, although this difference was not statistically significant (P=0.467). CONCLUSION: Using our indication criteria, which limited lesion size to ≤ 20 mm, satisfactory therapeutic outcomes of ER of SNADT were obtained.

Colorectal endoscopic submucosal dissection: Technical advantages compared to endoscopic mucosal resection and minimally invasive surgery.

BACKGROUND AND AIM: In recent years, the effectiveness of colorectal endoscopic submucosal dissection (ESD) has been increasingly reported. Herein, we highlight the most recent developments and technical advantages of colorectal ESD compared to EMR and minimally invasive surgery. METHODS: All candidate lesions for ESD were confirmed as being intramucosal tumors by colonoscopy. Presently, the indications for colorectal ESD approved by the Japanese government's medical insurance system are early colorectal cancers with a maximum tumor size of 2-5 cm; however, many early cancers >5 cm have been treated by ESD in referral centers. RESULTS: The primary advantage of ESD compared to endoscopic mucosal resection (EMR) is a higher en-bloc resection rate for large colonic tumors that had previously been treated by surgery. ESD has several advantages compared to other therapeutic modalities, such as being a safer technique and providing better quality of life. For rectal cancer treatment, a longer procedure time is required for laparoscopic assisted colectomy, whereas trans-anal resection and trans-anal endoscopic microsurgery are more invasive than ESD with a significantly higher recurrence rate. Accordingly, ESD is the preferred choice for early colorectal cancers when there is no risk of lymph-node metastasis. CONCLUSION: ESD is an effective procedure for treating non-invasive non-polypoid colorectal tumors. These tumors may be difficult to resect en bloc by conventional EMR. The use of ESD results in a higher en-bloc resection rate and is less invasive than surgery.

Treatment outcomes of endoscopic resection for nonampullary duodenal neuroendocrine tumors.

Background: The incidence rate of duodenal neuroendocrine tumors has been increasing in recent years. Endoscopic resection [ER; endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD)] is recommended for nonampullary duodenal neuroendocrine tumors (NAD-NETs) ≤10 mm in diameter that are confined to the submucosal layer and without lymph node or distant metastasis. However, the efficacy and safety of and indications for EMR/ESD remain unclear. Methods: Between November 2011 and April 2021, 12 NAD-NETs in 12 patients who underwent either EMR or ESD were analyzed retrospectively. The rates of en bloc resection, complete resection, pathologic complete resection, margin involvement, lymphovascular invasion, perineural invasion, complications and prognosis were determined during follow-up (median observation period 53.0 months). Results: EMR was performed for two tumors, and ESD was performed for ten tumors. En bloc resection was performed for both tumors (100%) in the EMR group, and complete resection was achieved in one case (50%). Pathological complete resection was achieved in one case (50%), while in the ESD group, these three rates were 90% (9/10), 80% (8/10), and 80% (8/10), respectively. Intraoperative perforation occurred in one patient (10%) during ESD treatment, with no intraoperative or delayed bleeding in either group. Recurrence and distant metastasis were not observed during the mean follow-up period of 53.0 months (range, 18-131 months). Conclusions: For NAD-NETs that measure ≤10 mm in size, are confined to the submucosal layer and have neither suspicious lymph nodes nor distant metastasis, ER (EMR and ESD) may be a safe, effective, and feasible endoscopic technique for removing them.

Analysis of risk factors for postoperative bleeding and polyp recurrence in adolescents with gastric polyps treated with endoscopic mucosal resection: a retrospective cohort study.

Background: The incidence of gastric polyps in adolescents has been increasing every year in recent years. Endoscopic mucosal resection (EMR) is one of the most common treatments for adults, but there are few reports on the association between EMR of gastric polyps and the occurrence of bleeding and recurrence after the procedure in adolescents. This study sought to analyze the independent risk factors for postoperative bleeding and polyp recurrence after EMR to provide a reference for reducing the occurrence of postoperative complications. Methods: We retrospectively analyzed the data of 579 adolescent patients who developed gastric polyps from June 2016 to June 2021. Postoperative follow-up was conducted for 1 year by telephone, e-mail, and outpatient review. The general characteristics of the study population were compiled using a general information questionnaire designed by the investigators. The relationship between the patients' clinical characteristics and postoperative bleeding or recurrence was analyzed using the chi-square test. A binary logistic regression analysis was conducted to analyze the independent risk factors for the occurrence of postoperative bleeding and polyp recurrence in patients. Results: The results of the binary logistic regression analysis showed that being female [odds ratio (OR) =0.306, P=0.009], polyps >1 cm in diameter (OR =2.557, P=0.029), polyps in gastric sinus (OR =3.889, P=0.032), sessile lesions (OR =0.398, P=0.036), the need for additional intraoperative sedation (OR =3.469, P=0.005), concurrent diverticulum (OR =3.570, P=0.004), and intraoperative bleeding (OR =4.855, P=0.001) were independent risk factors for postoperative bleeding. We also found that polyps >1 cm in diameter (OR =2.134, P=0.003), multiple polyps (OR =2.117, P=0.005), adenomatous polyps (OR =2.684, P=0.041), combined Helicobacter pylori infection (OR =2.036, P=0.009), the occurrence of postoperative gastrointestinal reflux (OR =1.998, P=0.015), and an operative time ≥40 min (OR =2.021, P=0.010) were independent risk factors for the recurrence of polyps. Conclusions: There is still a high probability of postoperative bleeding and polyp recurrence after EMR in adolescents with gastric polyps. Clinicians should pay close attention to the clinical features of polyps, such as polyp size, number, morphology, and pathological type, to identify the related risk factors as early as possible and reduce the probability of postoperative bleeding and polyp recurrence in patients.

Predictive factors of lymphatic metastasis and evaluation of the Japanese treatment guidelines for endoscopic resection of early gastric cancer in a high-volume center in Perú.

Purpose: This study aimed to identify the predictive factors of lymph node metastasis (LNM) in patients with early gastric cancer (EGC) and to evaluate the applicability of the Japanese treatment guidelines for endoscopic resection in the western population. Methods: Five hundred-one patients with pathological diagnoses of EGC were included. Univariate and multivariate analyses were conducted to identify the predictive factors of LNM. EGC patients were distributed according to the indications for endoscopic resection of the Eastern guidelines. The incidence of LNM was evaluated in each group. Results: From 501 patients with EGC, 96 (19.2%) presented LNM. In 279 patients with tumors with submucosal infiltration (T1b), 83 (30%) patients had LNM. Among 219 patients who presented tumors > 3 cm, 63 (29%) patients had LNM. Thirty-one percent of patients with ulcerated tumors presented LMN (33 out of 105). In 76 patients and 24 patients with lymphovascular and perineural invasion, the percentage of LMN was 84% and 87%, respectively. In the multivariate analysis, a tumor diameter >3 cm, submucosal invasion, lymphovascular, and perineural invasion were independent predictors of LMN in EGC. No patient with differentiated, non-ulcerated mucosal tumors presented LNM regardless of tumor size. Three of 17 patients (18%) with differentiated, ulcerated mucosal tumors and ≤ 3 cm presented LNM. No LNM was evidenced in patients with undifferentiated mucosal tumors and ≤ 2 cm. Conclusions: The presence of LNM in Western EGC patients was independently related to larger tumors (>3 cm), submucosal invasion, lymphovascular and perineural invasion. The Japanese absolute indications for EMR are safe in the Western population. Likewise, Western patients with differentiated, non-ulcerated mucosal tumors, and larger than 2 cm are susceptible to endoscopic resection. Patients with undifferentiated mucosal tumors smaller than 2 cm presented encouraging results and ESD could be recommended only for selected cases.