Long-term outcomes of endoscopic resection for duodenal neuroendocrine tumors.

Duodenal neuroendocrine tumors (d-NETs) ≤ 10 mm in size, confined to the submucosal layer, without lymph node or distant metastasis, can be treated safely and effectively by endoscopic management. However, most results are based on limited data and short follow-up outcomes. Herein, we aimed to evaluate the short-term and long-term outcomes of endoscopic resection for d-NETs. We retrospectively analyzed 63 patients with 68 d-NETs who had undergone endoscopic resection at two hospitals between January 2009 and December 2021. En-bloc resection, endoscopically complete resection, and histopathologically complete resection rates were evaluated as short-term outcomes. Furthermore, long-term outcomes were analyzed in 46 patients with 50 d-NETs with a follow-up period of > 1 year. The overall en-bloc, endoscopically complete, and histopathologically complete resection rates were 92.6% (63/68), 100% (68/68), and 69.1% (47/68), respectively. Tumor size (> 5 mm) was the only predictive factor for histopathologically incomplete resection (p = 0.015). The procedure-related bleeding and perforation rates were 0% and 5.9%, respectively. No recurrences were observed in patients with histopathologically complete resection and those with histopathologically incomplete resection at a median follow-up period of 48 months (range 12-132 months). Endoscopic resection for d-NETs ≤ 10 mm in size, limited to the submucosal layer, and without lymph node or distant metastasis provides favorable long-term outcomes when endoscopically complete resection is achieved.

Clinical strategies for securing negative proximal margin in early gastric cancer.

Securing an appropriate proximal resection margin (PRM) is crucial for oncological safety in treating gastric cancer. This study investigated the clinicopathological characteristics of patients with incomplete PRM length of <2 cm in early gastric cancer. Clinicopathological data of 1,493 patients who underwent subtotal gastrectomy for early gastric cancer in 2012 to 2021 were retrospectively reviewed. Patients were divided into the PRM length of <2 cm and ≥2 cm groups based on pathological results. Univariate and multivariate analyses evaluated factors for incomplete PRM length. Factors related to patients with a relative PRM positive were also analyzed. The proportion of patients with a PRM length of <2 cm was 17.9% (267/1,493). Multivariate regression analysis revealed that age <50, preoperative endoscopic size of ≥3 cm, size discrepancy of ≥2 cm, and midbody tumor with a lesser curvature significantly contributed to the PRM length of <2 cm. Twenty-four patients had a relative PRM positive (24/1493, 1.6%). An incomplete PRM was the only risk factor for a positive relative PRM. Surgical treatment for early gastric cancer requires an accurate preoperative endoscopic tumor size and location evaluation. A more aggressive resection is recommended for patients with age <50, preoperative endoscopic size of ≥3 cm, size discrepancy of ≥2 cm, and midbody tumor with a lesser curvature.

Clinical outcomes of esophageal granular cell tumors with different endoscopic resection methods.

Esophageal granular cell tumors (GCTs), the second most common subepithelial tumors (SETs) of the esophagus, are potentially malignant with no definite management guidelines available. We retrospectively enrolled 35 patients with endoscopically resected esophageal GCTs between December 2008 and October 2021 and evaluated the clinical outcomes from the various methods performed. Several modified endoscopic mucosal resections (EMRs) were performed for treating esophageal GCTs. Clinical and endoscopic outcomes were evaluated. Mean age of patients was 55.8 ± 8.2, with majority being men (57.1%). Mean tumor size was 7.2 ± 2.6 mm, most (80.0%) were asymptomatic and present in the distal third of the esophagus (77.1%). Endoscopic characteristics predominantly included broad-based (85.7%) and whitish-to-yellowish color changes (97.1%). Endoscopic ultrasound (EUS) of 82.9% of the tumors revealed homogeneous hypoechoic SETs originating from the submucosa. The five endoscopic treatment methods used were: ligation-assisted (77.1%), conventional (8.7%), cap-assisted (5.7%), and underwater (5.7%) EMRs and ESD (2.9%). Mean procedure time was 6.6 ± 2.1 min, and no procedure-associated complications were noted. The en-bloc and complete histologic resection rates were 100% and 94.3%, respectively. No recurrences were noted during follow-up, and no significant differences in the clinical outcomes of the different methods of endoscopic resection were found. Based on tumor characteristics and therapeutic outcomes, modified EMR methods can be effective and safe. However, there were no significant differences in the clinical outcomes of the different methods of endoscopic resection.

Understanding the Role of M13 Bacteriophage Thin Films on a Metallic Nanostructure through a Standard and Dynamic Model.

The dynamic and surface manipulation of the M13 bacteriophage via the meeting application demands the creation of a pathway to design efficient applications with high selectivity and responsivity rates. Here, we report the role of the M13 bacteriophage thin film layer that is deposited on an optical nanostructure involving gold nanoparticles/SiO2/Si, as well as its influence on optical and geometrical properties. The thickness of the M13 bacteriophage layer was controlled by varying either the concentration or humidity exposure levels, and optical studies were conducted. We designed a standard and dynamic model based upon three-dimensional finite-difference time-domain (3D FDTD) simulations that distinguished the respective necessity of each model under variable conditions. As seen in the experiments, the origin of respective peak wavelength positions was addressed in detail with the help of simulations. The importance of the dynamic model was noted when humidity-based experiments were conducted. Upon introducing varied humidity levels, the dynamic model predicted changes in plasmonic properties as a function of changes in NP positioning, gap size, and effective index (this approach agreed with the experiments and simulated results). We believe that this work will provide fundamental insight into understanding and interpreting the geometrical and optical properties of the nanostructures that involve the M13 bacteriophage. By combining such significant plasmonic properties with the numerous benefits of M13 bacteriophage (like low-cost fabrication, multi-wavelength optical characteristics devised from a single structure, reproducibility, reversible characteristics, and surface modification to suit application requirements), it is possible to develop highly efficient integrated plasmonic biomaterial-based sensor nanostructures.

Clinical and endoscopic characteristics of sessile serrated lesions with dysplasia/carcinoma.

BACKGROUND/AIMS: Some sessile serrated lesions (SSLs) progress into dysplasia and colorectal cancer, however, the clinical and endoscopic characteristics of SSLs with dysplasia remain to be determined. In this study, we elucidated these characteristics in SSLs with dysplasia/carcinoma, compared with those of SSLs without dysplasia. METHODS: We retrospectively collected the clinical, endoscopic, and pathological data of 254 SSLs from 216 patients endoscopically resected between January 2009 and December 2020. RESULTS: All SSLs included 179 without dysplasia and 75 with dysplasia/carcinoma, including 55 with low-grade dysplasia, 10 with high-grade dysplasia, and 10 with submucosal cancer. In clinical characteristics, SSLs with dysplasia/carcinoma were significantly associated with advanced age, metabolic diseases, and high-risk adenomas. In endoscopic characteristics, SSLs with dysplasia/carcinoma were significantly associated with the distal colon, large size, polypoid morphology, surface-changes, no mucus cap, and narrow-band imaging international colorectal endoscopic classification (NICE) type 2/3. In the multivariate analysis, high-risk adenomas (odds ratio [OR], 2.98; p = 0.01), large size (OR, 1.18; p < 0.01), depression (OR, 11.74; p = 0.03), and NICE type 2/3 (OR, 14.97; p < 0.01) were significantly associated with SSLs with dysplasia/carcinoma. CONCLUSION: SSLs had a higher risk of dysplasia in the distal colon than in the proximal colon. SSLs with large size, depression, and adenomatous surface-patterns, as well as those in patients with high-risk adenomas, increased the risk of dysplasia/ carcinoma. This suggests that the clinical and endoscopic characteristics can aid in the diagnosis and management of SSLs with dysplasia/carcinoma.

Local Recurrence after Endoscopic Submucosal Dissection of Early Gastric Cancer.

Endoscopic submucosal dissection (ESD) is considered the treatment of choice for early gastric cancer (EGC) with a negligible risk of lymph node metastasis. Locally recurrent lesions on artificial ulcer scars are difficult to manage. Predicting the risk of local recurrence after ESD is important to manage and prevent the event. We aimed to elucidate the risk factors associated with local recurrence after ESD of EGC. Between November 2008 and February 2016, consecutive patients (n = 641; mean age, 69.3 ± 9.5 years; men, 77.2%) with EGC who underwent ESD at a single tertiary referral hospital were retrospectively analyzed to evaluate the incidence and factors associated with local recurrence. Local recurrence was defined as the development of neoplastic lesions at or adjacent to the site of the post-ESD scar. En bloc and complete resection rates were 97.8% and 93.6%, respectively. The local recurrence rate after ESD was 3.1%. The mean follow-up period after ESD was 50.7 ± 32.5 months. One case of gastric cancer-related death (0.15%) was noted, wherein the patient had refused additive surgical resection after ESD for EGC with lymphatic and deep submucosal invasion. Lesion size ≥15 mm, incomplete histologic resection, undifferentiated adenocarcinoma, scar, and the absence of erythema of the surface were associated with a higher risk of local recurrence. Predicting local recurrence during regular endoscopic surveillance after ESD is important, especially in patients with a larger lesion size (≥15 mm), incomplete histologic resection, surface changes of scars, and no erythema of the surface.

Application of the Falciform Ligament Patch for the Prevention of Duodenal Stump Leakage After Gastrectomy: Technical Report on a Case Series.

Background: Duodenal stump leakage (DSL) is a serious complication after gastrectomy. In this study, we developed a novel prevention technique using a falciform ligament patch (FLP) to prevent DSL among high-risk patients after gastrectomy. Materials and Methods: From January 2019 to July 2021, 14 patients who were judged to be at high risk for DSL during preoperative examinations or surgery were included in this retrospective study, and the FLP was applied to the duodenal stump. The falciform ligament was separated from the liver after duodenal transection during gastrectomy; the end part was used to cover the duodenal stump and was fixed using nonabsorbable polypropylene sutures. Results: In total, 14 patients who underwent FLP had one or two risk factors that were identified: 5 patients, gastric cancer duodenal invasion; 4 patients, gastric outlet obstruction (GOO); 1 patient, cancer involving the distal resection margin; 1 patient, duodenal gastrointestinal stromal tumor involving the distal resection margin; 1 patient, gastric cancer duodenal invasion and GOO; and 2 patients, cancer involving the distal resection margin and GOO. FLP construction was successful, and no patient developed complications of DSL. The average hospital stay was 11.9 days, and the patients were discharged without any morbidities after surgery. Conclusions: Therefore, the FLP can be used to prevent DSL among high-risk patients after gastrectomy.

Efficacy and safety of one-step knife compared to conventional insulated-tip knife for endoscopic submucosal dissection: a preliminary study with prospective data collection and retrospective review.

BACKGROUND: Endoscopic submucosal dissection (ESD) is not as tiresome as gastrectomy, but it is a time-consuming procedure. One-step knife (OSK) is a novel knife that combines a knife for ESD and an injection needle into one sheath. In this study, we aimed to compare the insulated tip type of OSK and conventional knife (CK) in terms of procedure time and complication rate. METHODS: Medical records of patients with ESD using CK between February and September 2020 were retrospectively reviewed. Subsequently, data from patients who underwent ESD using OSK by September 2021 were prospectively collected. Total procedure time, procedure time by location and complication rate in the OSK and CK group were compared. RESULTS: In the study period, a total of 203 patients (OSK, 102 patients; CK, 101 patients) were analyzed. On multivariate analysis, using CK, body location, resection size ≥ 40 mm, and submucosal fibrosis were associated with longer procedure time. The total procedure time was statistically significantly reduced in the OSK group (median 11 vs. 17 min, p < 0.01). The procedure time for each location was more reduced in the body (median 14 vs. 19 min p < 0.01) than the antrum (median 10 vs. 14 min, p = 0.01) in the OSK group. There was no significant difference in post-ESD bleeding and perforation in the two groups (3.9 vs. 3.9%, p = 0.99 and 1.0 vs. 2.0%, p = 0.56). CONCLUSIONS: OSK significantly reduced the total procedure time of ESD. OSK could be an effective and safe knife for gastric ESD, especially for body lesions.

A large and pedunculated inflammatory pseudotumor with pseudosarcomatous change of the cecum mimicking a malignant polyp: a case report and literature review.

Inflammatory pseudotumor (IPT) is a rare benign tumor of unknown etiology that can occur in almost any organ system. It has neoplastic features such as local recurrence, invasive growth, and vascular invasion, leading to the possibility of malignant sarcomatous changes. The clinical presentations of colonic IPT may include abdominal pain, anemia, a palpable mass, and intestinal obstruction. A few cases of colonic IPT have been reported, but colonic IPT with pedunculated morphology is very rare. Furthermore, since it can mimic malignant polyps, understanding the endoscopic findings of colonic IPT is important for proper treatment. Herein, we present a case of colonic IPT with pseudosarcomatous changes, presenting as a large polyp, mimicking a malignant polyp in the cecum, along with a literature review.

Esophageal Stricture after Endoscopic Drainage of Esophageal Abscess as a Complication of Acute Phlegmonous Esophagitis: A Case Report.

Esophageal abscess caused by acute phlegmonous esophagitis is rare but life-threatening. Rapid abscess drainage is an important part of the treatment, and endoscope-assisted intra-luminal abscess drainage is frequently performed. Although endoscopic drainage is less invasive than surgery, it has the potential to cause esophageal stricture as a complication. We present a rare case of esophageal stricture as a complication of intra-luminal drainage and evaluate a method to minimize the incidence of esophageal stricture complications.

Efficacy of combination colonoscopy using modified cap-assisted and water-exchange colonoscopy with prone position for detection of colorectal adenomas.

The efficacy of cap-assisted and water-exchange colonoscopy, individually or in combination for adenoma detection is well documented. Moreover, prone positioning colonoscopy may also improve adenoma detection by decreasing loop formation. However, the efficacy of triple-combination colonoscopy using the above methods for adenoma detection is unclear. This study aimed to compare the effectiveness of combining modified cap-assisted and water-exchange colonoscopy with prone position (CWP) and conventional colonoscopy (CC) for adenoma detection. A total of 746 patients who underwent either CWP or CC, performed by 2 board-certified gastroenterologists between December 2019 and March 2020, were investigated retrospectively. Cap-assisted colonoscopy was modified using hooking and dragging maneuver. We evaluated the polyp detection rate (PDR), adenoma detection rate (ADR), and the mean number of adenomas detected per procedure (MAP). There was no significant difference in sex, age, the indication of colonoscopy and quality of bowel preparation between the 2 groups. PDR, ADR, and proximal colon MAP were significantly higher in the CWP group than in the CC group (PDR: 84.9% vs 59.8%, P < .01; ADR: 70.1%, vs 49.2%, P < .01; proximal colon MAP: 1.24 vs 0.55, P < .01). CWP is more effective than CC for PDR, ADR, and proximal colon MAP. Although it may facilitate adenoma detection, further studies assessing the synergistic or complementary effects of combining these methods are needed.

Combination conventional endoscopy and endoscopic ultrasound can differentiate between esophageal granular cell tumors and leiomyomas.

Esophageal leiomyomas and granular cell tumors (GCTs) are the 2 most common subepithelial tumors found in the esophagus. We attempted to differentiate the 2 tumors using endoscopic findings and endoscopic ultrasound (EUS) features. Between December 2008 and June 2021, a total of 38 esophageal GCTs and 11 esophageal leiomyomas originating from the muscularis mucosa were selected. Clinical characteristics and endoscopic features were retrospectively reviewed. Although esophageal GCTs are mainly located in the lower third of the esophagus (81.6%), esophageal leiomyomas are mainly located in the upper third of the esophagus (45.5%). Broad-based (84.2%, P = .002) and whitish-to-yellowish color changes (97.4%, P < .001) are significant endoscopic features of esophageal GCTs. The echogenicity of esophageal leiomyoma was similar to that of proper muscle echogenicity. However, the echogenicity of esophageal GCTs was hyperechoic compared to that of the proper muscle layer (90.0% vs 9.1%, respectively, P < .001). EUS revealed a clearer hyperechoic epithelial lining in the esophageal leiomyoma than in esophageal GCTs (100% vs 26.7%, respectively, P < .001). The 5 endoscopic factors (location of the lower third, broad base, whitish-to-yellowish color, hyper-echogenic, and unclear demarcated hyperechoic epithelial line) were counted to differentiate esophageal GCTs from esophageal leiomyomas. Tumors with 3 or more endoscopic factors were all esophageal GCTs. The characteristic endoscopic and EUS features of esophageal GCTs were broad-based, whitish-to-yellowish colored subepithelial tumors located in the lower third of the esophagus and hyperechoic tumor with an unclear demarcated hyperechoic epithelial line. A combination of these features can predict esophageal GCTs before endoscopic resection.

Underwater endoscopic mucosal resection of upper gastrointestinal subepithelial tumors: A case series pilot study (with video).

INTRODUCTION: Underwater endoscopic mucosal resection (UW-EMR) has been recently introduced as an effective technique for rectal third layer subepithelial tumors. Therefore, we aimed to assess the safety, efficacy, and procedure time of UW-EMR for upper gastrointestinal subepithelial tumors (SETs) originating from the deep mucosal and/or submucosal layers. METHODS: Between August 2018 to July 2022, a total of 17 SETs (7 duodenal SETs, 6 gastric SETs, and 4 esophageal SETs) were included in this study. On endoscopic ultrasound examinations, the tumors were found to be embedded in the submucosa without muscularis propria invasion. All SETs were resected successfully using UW-EMR. The characteristics of the tumors and their R0 resection rate, adverse event rate, and recurrence rate were evaluated retrospectively. RESULTS: The mean tumor size was 0.9 cm (range, 0.3-1.5 cm). En bloc resection and complete resection rates were 100%, respectively. The patients showed no complications such as perforation or bleeding. Histologic assessments of the resected tumors revealed 9 neuroendocrine tumors (7 on the duodenum, 2 on the stomach), 2 gastric cystica profunda, 1 gastric follicular lymphoma, 1 gastric fibromyxoma, 3 esophageal granular cell tumors, and 1 esophageal adenoid cystic carcinoma. The mean procedural time was 3.2 min (range, 1.3-8.7 minutes). The overall en bloc and complete resection rates were 100%, respectively. No recurrence was observed during the follow-up period. CONCLUSION: UW-EMR is a safe and effective treatment for upper gastrointestinal SETs embedded in the submucosal layer. Further studies are needed to compare other endoscopic resection techniques.

Clinical outcomes of gastroduodenal neuroendocrine tumors according to their WHO grade: A single-institutional retrospective analysis.

The management of gastroduodenal neuroendocrine tumor (NET) has been controversial between radical surgical resection and local excision including endoscopic resection. A gastroduodenal NET grade (G), measured by their mitotic rate and Ki67 proliferation index, is important to predict prognosis. In this study, we aimed to compare the clinical outcomes of gastroduodenal NET according to grades in order to identify poor prognostic factors of gastroduodenal NETs. Fifty-four gastroduodenal NETs diagnosed between December 2008 and December 2020 in a tertiary referral hospital were retrospectively reviewed. The clinical outcomes of gastroduodenal NETs, according to tumor grades and factors associated with NET G2-3, were analyzed. A total of 52 gastroduodenal NET patients was enrolled. The mean follow-up period was 56.2 ± 40.1 months. The mean size of gastric and duodenal NET was 7.9 ± 11.0 mm and 9.8 ± 7.6 mm, respectively. During the study period, 72.7% (16/22) of gastric NETs and 83.3% (25/30) of duodenal NETS were G1. All G1 gastroduodenal NETs showed no lymph node or distant metastasis during the study periods. All G3 gastroduodenal NETs showed metastasis (one lymph node metastasis and 3 hepatic metastases). Among metastatic NETs, the smallest tumor size was a 13 mm gastric G3 NET. Factors associated with G2-3 NETs were larger tumor size, mucosal ulceration, proper muscle or deeper invasion, and lymphovascular invasion. A small-sized gastroduodenal NET confined to submucosa without surface ulceration may be suitable for endoscopic resection. After local resection of a gastroduodenal NET (G1) without lymphovascular and muscle proper invasion, follow-up examination without radical surgical resection can be recommended. G3 NETs may be treated by radical surgical resection, regardless of tumor size.

Differences in Factors Predicting Lymph Node Metastasis Between pT1 Rectal Cancer and pT1 Colon Cancer: A Retrospective Study.

BACKGROUND: Studies have demonstrated conflicting results regarding factors that predict lymph node metastasis (LNM) in pT1 colorectal cancers. We hypothesized that these discrepancies could be related to different factors predicting LNM between rectal and colon cancer. This study aimed to compare predicting factors for LNM between pT1 rectal and colon cancer. METHODS: This retrospective study evaluated a prospectively maintained database that included 380 patients with pT1 colorectal cancer from January 2010 to December 2020. Patients were grouped according to whether they had rectal or colon cancer, with or without LNM, and factors predicting LNM were analyzed. RESULTS: In pT1 rectal cancer, LNM was associated with deeper submucosal (SM) invasion (P = .024) and a higher proportion of poorly differentiated tumors (P = .006). In pT1 colon cancer, LNM was associated with a higher proportion of moderately/poorly differentiated tumors (P = .002) and lymphatic invasion (P = .004). In the multivariate analysis for rectal cancer, depth of SM invasion (≥3000 µm) was an independent predictive factor for LNM (95% confidence interval [CI], 1.48-27.94; P = .013), whereas for colon cancer, moderately/poorly differentiated tumors (95% CI, 1.38-8.13; P = .008) and lymphatic invasion (95% CI, 1.44-11.78; P = .008) were independent predictive factors for LNM. DISCUSSION: There were distinct differences in the factors predicting LNM between pT1 rectal cancer and colon cancer. These results suggest the necessity in differentiating between rectal and colon cancer when performing studies on LNM in pT1 colorectal cancer.

A 3-year follow-up study of uncut Roux-en-Y reconstruction: clinical results and outcomes.

BACKGROUND: The goal of this study was to identify the clinical outcomes of uncut Roux-en-Y reconstruction in patients who underwent totally laparoscopic distal gastrectomy (TLDG) over 3-year follow-up. METHODS: From January 2016 to December 2017, 269 patients who underwent TLDG were enrolled in the study and analyzed retrospectively. They were classified into two groups according to the reconstruction method: uncut Roux-en-Y reconstruction (uncut RY) (n = 154) and Billroth II with Braun anastomosis (B-II/Braun) (n = 115). Postoperative endoscopic findings (residual food, bile reflux, gastritis, and esophagitis) and nutritional status (body weight, serum hemoglobin, total protein, and albumin levels) were assessed every 6 months for 3 years. RESULTS: Residual food was less frequent in the uncut RY group in the 6th month after TLDG (p = 0.022), but there were no differences between the two groups for the rest of the study period. The incidence of bile reflux and gastritis was low in the uncut RY group during all postoperative periods (all p < 0.001). In the B-II/Braun group, the frequency of reflux esophagitis was high in the 30th and 36th months after TLDG (both p < 0.001), and there were no differences between the two groups during the preceding periods. No significant differences were found with respect to nutritional status, such as body weight, serum hemoglobin, total protein, and albumin levels during all postoperative periods. CONCLUSIONS: Three-year follow-up outcomes showed that uncut RY can effectively reduce the incidence of bile reflux and gastritis in the remnant stomach compared to B-II/Braun after TLDG.

[Diagnosis and Treatment of Eosinophilic Esophagitis].

Eosinophilic esophagitis (EoE) is a chronic, immune/antigen-mediated esophageal disease characterized by symptoms of esophageal dysfunction and eosinophil-predominant inflammation. The diagnostic criteria for EoE have changed with our growing knowledge over the past two decades. Esophageal eosinophilia, which responds histologically to a proton pump inhibitor (PPI) is not a distinct disease but a subset of EoE. An endoscopic scoring system that relies on the assessment of exudates, rings, edema, furrows, and strictures is a useful tool for assessing endoscopic severity. PPIs are regarded as safe and effective first-line treatments for EoE. Oral topical corticosteroids or dietary therapy are also options for first-line treatment. Endoscopic dilation is effective for relieving the dysphagia symptoms of a patient with an esophageal stricture.