Potential for expanding indications and curability criteria of endoscopic resection for early gastric cancer in elderly patients: results from a Japanese multicenter prospective cohort study.

BACKGROUND AND AIMS: Evidence for endoscopic resection (ER) in elderly patients with early gastric cancer (EGC) is limited. We assessed its clinical outcomes, and explored new indications and curability criteria. METHODS: We analyzed data from a Japanese multicenter prospective cohort study. Patients aged ≥75 years with EGC treated with ER were included. We classified "eCuraC-2 (corresponding to noncurative ER, defined in the Japanese gastric cancer treatment guidelines)" into "elderly-high (EL-H)" (>10% estimated metastatic risk) and "elderly-low (EL-L)" (≤10%). RESULTS: In total, 3,371 patients with 3,821 EGCs were included; endoscopic submucosal dissection (ESD) was the prominent treatment choice. Among them, 3,586 lesions met the guidelines' ER indications and 235 did not. The proportions of en bloc and R0 resections and perforations were 98.9%, 94.4%, and 0.8%, respectively, in EGCs within the indications. In EGCs beyond the indications, they were 99.5%, 85.4%, and 5.9%, respectively, for lesions diagnosed as ≤3 cm, and 96.0%, 64.0%, and 18.0% for those >3 cm. Curative ER ("eCuraA/B") and EL-L were observed in 83.6% and 6.2% of lesions within the indications, respectively, and in 44.2% and 16.8% of lesions <3 cm beyond the indications, respectively. The 5-year cumulative gastric cancer death rates following eCuraA/B and EL-H were 0.3% (95% CI, 0.2-0.6) and 3.5% (2.0-5.7), respectively. Following EL-L, the rate was 0.9% (0.2-3.5) even without subsequent treatment. CONCLUSIONS: Usefulness of ESD for elderly EGC patients was confirmed by their clinical outcomes. Lesions ≤3 cm and EL-L emerged as new ER indication and curability criterion, respectively.

Usefulness of third-generation narrow band imaging and texture and color enhancement imaging in improving visibility of superficial early gastric cancer: A study using color difference.

Objectives: Overlooking early gastric cancer (EGC) during endoscopy is an issue to be resolved. Image-enhanced endoscopy is expected to improve EGC detection. This study investigated the usefulness of third-generation narrow band imaging (3G-NBI) and texture and color enhancement imaging (TXI) in improving the visibility of EGC using the color difference between EGC and its surrounding gastric mucosa. Methods: In this retrospective observational study, we examined 51 superficial EGCs that underwent endoscopic submucosal dissection and were observed by all three methods: 3G-NBI, TXI, and white light imaging (WLI). The primary endpoint was to compare the color difference of each method. For each EGC, we prepared one non-magnifying image for each method so that the location and size of the lesion in each image were the same. The L*a*b* color space was used to evaluate the color values. When the color values of the cancerous lesion and its surrounding mucosa were (L*c, a*c, b*c) and (L*s, a*s, b*s), respectively, the color difference was defined to be [(L*c-L*s)2+(a*c-a*s)2+(b*c-b*s)2]1/2. Results: The median color difference was 9.2 (interquartile range, 5.3-15.7) in WLI, 13.5 (interquartile range, 9.4-19.5) in 3G-NBI, and 15.3 (interquartile range, 9.1-22.1) in TXI. Statistically, the color difference was significantly larger in 3G-NBI than in WLI (p < 0.001) and TXI compared with WLI (p < 0.001). However, there was no significant difference between 3G-NBI and TXI (p = 0.330). Conclusions: Regarding color difference, both 3G-NBI and TXI were estimated to be more useful than WLI in improving the visibility of superficial EGC.

Long-term Survival After Endoscopic Resection For Gastric Cancer: Real-world Evidence From a Multicenter Prospective Cohort.

BACKGROUND & AIMS: We aimed to clarify the long-term outcomes of endoscopic resection (ER) for early gastric cancers (EGCs) based on pathological curability in a multicenter prospective cohort study. METHODS: We analyzed the long-term outcomes of 9054 patients with 10,021 EGCs undergoing ER between July 2010 and June 2012. Primary endpoint was the 5-year overall survival (OS). The hazard ratio for all-cause mortality was calculated using the Cox proportional hazards model. We also compared the 5-year OS with the expected one calculated for the surgically resected patients with EGC. If the lower limit of the 95% confidence interval (CI) of the 5-year OS exceeded the expected 5-year OS minus a margin of 5% (threshold 5-year OS), ER was considered to be effective. Pathological curability was categorized into en bloc resection, negative margins, and negative lymphovascular invasion: differentiated-type, pT1a, ulcer negative, ≤2 cm (Category A1); differentiated-type, pT1a, ulcer negative, >2 cm or ulcer positive, ≤3 cm (Category A2); undifferentiated-type, pT1a, ulcer negative, ≤2 cm (Category A3); differentiated-type, pT1b (SM1), ≤3 cm (Category B); or noncurative resections (Category C). RESULTS: Overall, the 5-year OS was 89.0% (95% CI, 88.3%-89.6%). In a multivariate analysis, no significant differences were observed when the hazard ratio of Categories A2, A3, and B were compared with that of A1. In all the pathological curability categories, the lower limit of the 95% CI for the 5-year OS exceeded the threshold 5-year OS. CONCLUSION: ER can be recommended as a standard treatment for patients with EGCs fulfilling Category A2, A3, and B, as well as A1 (UMIN Clinical Trial Registry, UMIN000005871).

Resection depth and layer of underwater versus conventional endoscopic mucosal resection of intermediate-sized colorectal polyps: A pilot study.

Background and study aims Curability of colorectal tumors is associated with resection depth and layer in endoscopic resection. Underwater endoscopic mucosal resection (UEMR) has not undergone sufficient histopathological evaluation. We conducted a pilot study to compare the effectiveness, including resection depth and layer, of UEMR and conventional endoscopic mucosal resection (CEMR). Patients and methods This study was a single-center, retrospective study. Patients with colorectal lesions were treated by UEMR or CEMR between January 2018 and March 2020. Eligible patients were selected from included patients in a 1:1 ratio using propensity score matching. We compared the resection depth and layer and treatment results between the UEMR and CEMR groups. Results We evaluated 55 patients undergoing UEMR and 291 patients undergoing CEMR. Using propensity score matching, we analyzed 54 lesions in each group. The proportion of specimens containing submucosal tissue was 100 % in both groups. The median thickness of the submucosal tissue was significantly greater in the CEMR group than in the UEMR group [1235 µm (95 % confidence interval [CI], 1020-1530 µm) vs. 950 µm (95 % CI, 830-1090 µm), respectively]. However, vertical margins were negative in all lesions in both groups. Conclusions Our findings suggest that the median thickness of submucosal tissue in the UEMR group was about 1,000 µm. Even though the resection depth achieved with UEMR was more superficial than that achieved with CEMR, UEMR may be a treatment option, especially for colorectal lesions ≤ 20 mm in diameter without suspicious findings of submucosal deeply invasive cancer.

[Number of hospitalizations due to colonic diverticular bleeding as a predictive factor for readmission:an exploratory study].

Colonic diverticular bleeding often recurs and requires hospital readmission. This study aimed to examine the relationship between the rate of readmission and the number of hospitalizations due to colonic diverticular bleeding. We retrospectively studied 98 patients first admitted between January 2008 and July 2017 for the treatment of colonic diverticular bleeding. We investigated the subsequent number of hospitalizations due to colonic diverticular bleeding and classified the patients into 3 groups:those admitted for the first time (first group), those admitted for the second time (second group), and those admitted for the third time or later (third group). Generally, the readmission rate increased as the number of hospitalizations increased (P<0.01). The 1-year readmission rates were 11.6%, 23.2%, and 34.2% in the first, second, and third groups, respectively. The 2-year readmission rates were 15.1%, 50.1%, and 62.4% in the first, second, and third groups, respectively. The 3-year readmission rates were 21.7%, 50.1%, and 74.9% in the first, second, and third groups, respectively. Thus, the number of hospitalizations due to colonic diverticular bleeding could be a predictive factor for readmission. We also classified the patients into 2 additional groups:those who had been readmitted (readmission group) and those who had not (no readmission group). Furthermore, we examined background and therapeutic factors, and found hypovolemic shock on admission to be an independent risk factor (odds ratio 14.1). Preventive treatments for such high-risk patients should be considered.

Transoral surgery for superficial head and neck cancer: National Multi-Center Survey in Japan.

Head and neck cancers, especially in hypopharynx and oropharynx, are often detected at advanced stage with poor prognosis. Narrow band imaging enables detection of superficial cancers and transoral surgery is performed with curative intent. However, pathological evaluation and real-world safety and clinical outcomes have not been clearly understood. The aim of this nationwide multicenter study was to investigate the safety and efficacy of transoral surgery for superficial head and neck cancer. We collected the patients with superficial head and neck squamous cell carcinoma who were treated by transoral surgery from 27 hospitals in Japan. Central pathology review was undertaken on all of the resected specimens. The primary objective was effectiveness of transoral surgery, and the secondary objective was safety including incidence and severity of adverse events. Among the 568 patients, a total of 662 lesions were primarily treated by 575 sessions of transoral surgery. The median tumor diameter was 12 mm (range 1-75) endoscopically. Among the lesions, 57.4% were diagnosed as squamous cell carcinoma in situ. The median procedure time was 48 minutes (range 2-357). Adverse events occurred in 12.7%. Life-threatening complications occurred in 0.5%, but there were no treatment-related deaths. During a median follow-up period of 46.1 months (range 1-113), the 3-year overall survival rate, relapse-free survival rate, cause-specific survival rate, and larynx-preservation survival rate were 88.1%, 84.4%, 99.6%, and 87.5%, respectively. Transoral surgery for superficial head and neck cancer offers effective minimally invasive treatment. Clinical trials registry number: UMIN000008276.

White globe appearance is an endoscopic predictive factor for synchronous multiple gastric cancer.

BACKGROUND: White globe appearance (WGA) is a small white lesion with a globular shape identified during magnifying endoscopy with narrow-band imaging. However, the association between WGA and synchronous multiple gastric cancer (SMGC) remains unclear. METHODS: Consecutive patients who underwent endoscopic submucosal dissection for gastric cancer (GC) between July 2013 and April 2015 at our institution were eligible for this study. We excluded patients with a history of gastric tumor or gastrectomy. Patients who had more than 2 GCs in their postoperative pathological evaluation were classified as SMGC-positive, and patients who had at least 1 WGA-positive GC were classified as WGA-positive patients. The primary outcome was a comparison of the prevalence of WGA in patients classified as SMGC-positive and SMGC-negative. Univariate and multivariate analyses were performed using the following variables: WGA, age, sex, atrophy, and Helicobacter pylori (H. pylori) status. RESULTS: There were 26 and 181 patients classified as SMGC-positive and SMGC-negative, respectively. Univariate analysis revealed that WGA-positive classification (50% vs. 23%, P=0.008) and male sex (88% vs. 66%, P=0.02) were significant factors associated with SMGC classification, while age ≥65 years (81% vs. 81%, P>0.99), severe atrophy (46% vs. 46%, P>0.99), and H. pylori positivity (69% vs. 65%, P=0.8) were not. In the multivariate analysis, only WGA-positive classification (odds ratio 2.78, 95% confidence interval 1.16-6.67; P=0.02) was a significant independent risk factor for SMGC. CONCLUSIONS: Our exploratory study showed the possibility of WGA as a predictive factor for SMGC. In cases of WGA-positive gastric cancer, careful examination might be needed to diagnose SMGC.

Effectiveness of planned surveillance for detecting second primary head and neck cancers after endoscopic resection of esophageal squamous cell carcinoma.

BACKGROUND: Second primary head and neck cancers after endoscopic resection of esophageal squamous cell carcinoma adversely affect patients' outcomes and the quality of life; however, an adequate surveillance schedule remains unclear. METHODS: We analyzed 330 patients with early esophageal squamous cell carcinoma who underwent endoscopic resection and were registered in the multicenter cohort study to evaluate adequate surveillance for detection of second primary head and neck cancers. Gastrointestinal endoscopists examined the head and neck regions after 3-6 months of endoscopic resection for esophageal squamous cell carcinoma and subsequently every 6 months. An otolaryngologist also examined the head and neck regions at the time of endoscopic resection for esophageal squamous cell carcinoma and at 12 months intervals thereafter. RESULTS: During the median follow-up period of 49.4 months (1.3-81.2 months), 33 second primary head and neck cancers were newly detected in 20 patients (6%). The tumor site was as follows: 22 lesions in the hypopharynx, eight lesions in the oropharynx, two lesions in larynx and one lesion in the oral cavity. The 2-year cumulative incidence rate of second primary head and neck cancers was 3.7%. Among them, 17 patients with 29 lesions were treated by transoral surgery. One patient with two synchronous lesions was treated by radiotherapy. Two lesions in two patients were not detected after biopsy. All patients were cured with preserved laryngeal function. CONCLUSIONS: Surveillance by gastrointestinal endoscopy every 6 months and surveillance by an otolaryngologist every 12 months could detect second primary head and neck cancers at an early stage, thereby facilitating minimally invasive treatment.

Long-term outcome of endoscopic resection for intramucosal esophageal squamous cell cancer: a secondary analysis of the Japan Esophageal Cohort study.

BACKGROUND: Prospectively collected long-term data of patients undergoing endoscopic resection for superficial esophageal squamous cell carcinoma (ESCC) are limited. The aim of this study was to determine the prospectively collected long-term outcomes of endoscopic resection for ESCC as a secondary analysis of the Japan Esophageal Cohort (JEC) study. METHODS: Patients who underwent endoscopic resection of intramucosal ESCC at 16 institutions between September 2005 and May 2010 were enrolled in the JEC study. All patients underwent endoscopic examination with iodine staining at 3 and 6 months after resection, and every 6 months thereafter. We investigated clinical courses after endoscopic resection, survival rates, and cumulative incidence of metachronous ESCC. RESULTS: 330 patients (mean age 67.0 years) with 396 lesions (mean size 20.4 mm) were included in the analysis. Lesions were diagnosed as high-grade intraepithelial neoplasia in 17.4 % and as squamous cell carcinoma in 82.6 % (limited to epithelium in 28.4 %, to lamina propria in 55.4 %, and to muscularis mucosa in 16.2 %). En bloc resection was achieved in 291 (73.5 %). The median follow-up period was 49.4 months. Local recurrences occurred in 13 patients (3.9 %) and were treated by endoscopic procedures. Lymph node metastasis occurred in two patients (0.6 %) after endoscopic resection. The 5-year overall, disease-specific, and metastasis-free survival rates were 95.1 %, 99.1 %, and 94.6 %, respectively. The 5-year cumulative incidence rate of metachronous ESCC was 25.7 %. CONCLUSIONS: Our study demonstrated that endoscopic resection is an effective treatment for intramucosal ESCC, with favorable long-term outcomes.

Association between the findings of metachronous secondary primary malignancies and the number of Lugol-voiding lesions.

This study was designed to evaluate the relation between dysplastic squamous epithelium in the esophageal mucosa and the development of metachronous secondary primary malignancies (mSPM) other than esophagus after endoscopic resection (ER) in patients with early esophageal squamous cell carcinoma (SCC). We studied 330 patients with early esophageal SCC who underwent ER as a post hoc analysis of a prospective multicenter cohort study (UMIN Clinical Trials Registry ID UMIN000001676). Lugol-voiding lesions (LVL) were graded into 3 categories (A = no lesion; B = 1 to 9 lesions; C ≥ 10 lesions). The following variables were studied: (i) the incidences of mSPM other than esophagus; (ii) the standardized incidence ratios (SIRs) of mSPM; (iii) the cumulative incidence and total number of mSPM other than esophagus; and (iv) predictors of mSPM other than esophagus on analysis with a multivariate Cox proportional-hazards model. After a median follow-up of 46.6 months, mSPM other than esophagus was diagnosed in a total of 73 patients (90 lesions). Among the 106 patients in group C, 37 patients had mSPM (51 lesions), including head and neck cancer in 14 patients (24 lesions) and gastric cancer in 12 patients (16 lesions). The SIR of mSPM was 3.61 in this study subjects. An increase in the LVL grade (A to B to C) was associated with a progressive increase in the cumulative incidence rate of mSPM other than esophagus (P = 0.017 for A vs. C, P = 0.023 for B vs. C). An increase in the LVL grade (A to B to C) was also associated with a progressive increase in the total number of mSPM other than esophagus per 100 person-years (primary events, relative risk [RR] = 1.66 and 3.24 for grades B and C, respectively, vs. A, P = 0.002 for trend; all events, RR = 1.81 and 4.66 for grades B and C, respectively, vs. A, P < 0.0001 for trend). LVL grade C was a strong predictor of mSPM other than esophagus (RR = 3.41 for A vs. C). LVL grade may be a useful predictor of the risk of mSPM other than esophagus after ER in patients with early esophageal SCC.

Optimal number of endoscopic biopsies for diagnosis of early gastric cancer.

Background and study aims No recommendations are available for optimal number of endoscopic biopsies for early gastric cancer (GC), and whether detection of early GC is improved by increasing the number of biopsy is unclear. We therefore evaluated the relationship between number of biopsies and diagnostic accuracy. Materials and methods We retrospectively evaluated 858 early GCs (623 from endoscopic submucosal dissection and 235 surgical specimens), which we classified as obtained after one, two, or three or more biopsies. We assessed diagnostic accuracy by number of biopsies, and in subgroups by tumor diameter, gross type, and surface color. Results Almost half the lesions were obtained after one biopsy each, 30 % after two biopsies, and 20 % after three or more biopsies. Although diagnostic accuracy increased with biopsy number, it was significantly greater for the two-biopsy group than the one-biopsy group, (92.5 % vs. 83.9 %, P  = 0.0009), but did not significantly differ between the two- and three or more-biopsy groups. This finding was seen when tumors were evaluated by size, but not by elevated type and surface color, for which more biopsies did not improve diagnostic accuracy. Multivariate analysis demonstrated that two or more biopsies was the independent significant factors for diagnostic accuracy. Conclusions Two biopsies are the optimal number required to diagnose early GC.

Clinical outcomes of the "resect and discard" strategy using magnifying narrow-band imaging for small (< 10 mm) colorectal polyps.

Background and study aim The "resect and discard" strategy is a new paradigm for the management of small colorectal polyps that reduces the cost and effort related to pathological diagnosis after polypectomy. This retrospective study aimed to clarify the clinical outcome of the "resect and discard" strategy for small colorectal polyps. Patients and methods The clinical records were reviewed from 501 consecutive patients who underwent the "resect and discard" strategy for colorectal polyps smaller than 10 mm at our hospital between January 2008 and December 2010. All colorectal lesions were evaluated onsite under magnifying narrow-band imaging after careful conventional white-light imaging. In cases of low grade adenoma predicted with high confidence, colonoscopists selected the "resect and discard" option without formal histopathology. The mid-term outcomes were evaluated to validate the curability of the "resect and discard" strategy. Results The present study included 501 consecutive patients with 816 lesions. The mid-term outcomes were examined for 476 (95 %) patients who received follow-up for at least 1 year after undergoing the "resect and discard" strategy. The median observation period was 83 months (range 12 - 117 months). No patient died from colorectal cancer related to the procedure, resulting in a disease-specific survival rate of 100 %. There were no local and/or distant recurrences detected during follow-up. Conclusions The "resect and discard" strategy for small colorectal polyps under strict preoperative diagnosis achieves excellent mid-term outcome.

Effectiveness of clip-and-snare method using pre-looping technique for gastric endoscopic submucosal dissection.

AIM: To evaluate efficacy and safety of clip-and-snare method using pre-looping technique (CSM-PLT) for gastric endoscopic submucosal dissection (ESD). METHODS: In the CSM-PLT method, a clip attached to the lesion side was strangulated with a snare, followed by application of an appropriate tension to the lesion independent of an endoscope. Twenty consecutive lesions were resected by ESD using CSM-PLT (CSM-PLT group) and compared with a control group, including 20 lesions that were resected by conventional ESD. The control group was matched based on the size and location of the lesion, presence of pathologic fibrosis, and experience of endoscopists. Total procedure time of ESD, proportion of en bloc resection, and complications were analyzed. RESULTS: The total procedure time for the CSM-PLT group was significantly shorter than that for the control group (38.5 min vs 59.5 min, P = 0.023); all lesions were resected en bloc by ESD. There was no significant difference in complications between the two groups. Moreover, there was no complication in the CSM-PLT group. In one large lesion (size: 74 mm) that underwent extensive CSM-PLT during ESD, we used an additional CSM-PLT on another edge of the lesion after achieving submucosal resection to the maximum extent possible during initial CSM-PLT. In two lesions, the snare came off the lesion together with the clip after a sudden pull; nevertheless, ESD was successful in all lesions. CONCLUSION: CSM-PLT was an effective and safe method for gastric ESD.

Importance of colonoscopy in patients undergoing endoscopic resection for superficial esophageal squamous cell carcinoma.

BACKGROUND: The aim of the study was to clarify the frequency of colorectal neoplasm (CRN) complicating superficial esophageal squamous cell carcinoma (ESCC) and the need for colonoscopy. METHODS: We retrospectively reviewed 101 patients who had undergone initial endoscopic resection (ER) for superficial ESCC. Control group participants were age- and sex-matched asymptomatic subjects screened at our hospital over the same period of time. Advanced adenoma was defined as an adenoma ≥10 mm, with villous features, or high-grade dysplasia. Advanced CRN referred to advanced adenoma or cancer. We measured the incidence of advanced CRN in superficial ESCC and controls, and we compared the characteristics of superficial ESCC patients with and without advanced CRN. RESULTS: In the superficial ESCC group, advanced CRNs were found in 17 patients (16.8%). A history of smoking alone was found to be a significant risk factor of advanced CRN [odds ratio 6.02 (95% CI 1.30-27.8), P=0.005]. CONCLUSION: The frequency of synchronous advanced CRN is high in superficial ESCC patients subjected to ER. Colonoscopy should be highly considered for most patients who undergo ER for superficial ESCC with a history of smoking, and is recommended even in superficial ESCC patients.

Recent traction methods for endoscopic submucosal dissection.

Endoscopic mucosal resection (EMR) is problematic with regard to en bloc and curable resection rates. Advancements in endoscopic techniques have enabled novel endoscopic approaches such as endoscopic submucosal dissection (ESD), which has overcome some EMR problems, and has become the standard treatment for gastrointestinal tumors. However, ESD is technically difficult. Procedure time is longer and complications such as intraoperative perforation and bleeding occur more frequently than in EMR. Recently various traction methods have been introduced to facilitate ESD procedures, such as clip with line, external forceps, clip and snare, internal traction, double scope, and magnetic anchor. Each method must be used appropriately according to the anatomical characteristics. In this review we discuss recently proposed traction methods for ESD based on the characteristics of various anatomical sites.

White globe appearance is a novel specific endoscopic marker for gastric cancer: A prospective study.

BACKGROUND AND AIM: White globe appearance (WGA) is a small white lesion with a globular shape that can be identified by magnifying endoscopy with narrow-band imaging (M-NBI). WGA was recently reported as a novel endoscopic marker that can differentiate between gastric cancer (GC) and low-grade adenoma. However, the usefulness of WGA for differentiating GC from non-cancerous lesions (NC), including those of gastritis, is unknown. METHODS: To compare the prevalence of WGA in GC and NC, we carried out a prospective study of 994 patients undergoing gastroscopy. All patients were examined for target lesions that were suspected to be GC. When a target lesion was detected, the presence or absence of WGA in the lesion was evaluated using M-NBI, and all target lesions were biopsied or resected for histopathological diagnosis. Primary endpoint was a comparison of WGA prevalence in GC and NC. Secondary endpoints included WGA diagnostic performance for diagnosing GC. RESULTS: A total of 188 target lesions from 156 patients were analyzed for WGA, and histopathological diagnoses included 70 cases of GC and 118 cases of NC. WGA prevalence in GC and NC was 21.4% (15/70) and 2.5% (3/118), respectively (P < 0.001). WGA diagnostic accuracy, sensitivity, and specificity for detecting GC were 69.1%, 21.4%, and 97.5%, respectively. CONCLUSIONS: WGA prevalence in GC is significantly higher than that in NC. Because WGA is highly specific for GC, the presence of WGA is useful to diagnose GC.

Residual Tensile Property of Plain Woven Jute Fiber/Poly(Lactic Acid) Green Composites during Thermal Cycling.

This study investigated the residual tensile properties of plain woven jute fiber reinforced poly(lactic acid) (PLA) during thermal cycling. Temperature ranges of thermal cycling tests were 35-45 °C and 35-55 °C. The maximum number of cycles was 10³ cycles. The quasi-static tensile tests of jute fiber, PLA, and composite were conducted after thermal cycling tests. Thermal mechanical analyses of jute fiber and PLA were conducted after thermal cycling tests. Results led to the following conclusions. For temperatures of 35-45 °C, tensile strength of composite at 10³ cycles decreased 10% compared to that of composite at 0 cycles. For temperatures of 35-55 °C, tensile strength and Young's modulus of composite at 10³ cycles decreased 15% and 10%, respectively, compared to that of composite at 0 cycles. Tensile properties and the coefficient of linear expansion of PLA and jute fiber remained almost unchanged after thermal cycling tests. From observation of a fracture surface, the length of fiber pull out in the fracture surface of composite at 10³ cycles was longer than that of composite at 0 cycles. Therefore, tensile properties of the composite during thermal cycling were decreased, probably because of the decrease of interfacial adhesion between the fiber and resin.

Preoperative endoscopic diagnosis of superficial non-ampullary duodenal epithelial tumors, including magnifying endoscopy.

Superficial non-ampullary duodenal epithelial tumor (SNADET) is defined as a sporadic tumor that is confined to the mucosa or submucosa that does not arise from Vater's papilla, and it includes adenoma and adenocarcinoma. Recent developments in endoscopic technology, such as high-resolution endoscopy and image-enhanced endoscopy, may increase the chances of detecting SNADET lesions. However, because SNADET is rare, little is known about its preoperative endoscopic diagnosis. The use of endoscopic resection for SNADET, which has no risk of metastasis, is increasing, but the incidence of complications, such as perforation, is significantly higher than in any other part of the digestive tract. A preoperative diagnosis is required to distinguish between lesions that should be followed up and those that require treatment. Retrospective studies have revealed certain endoscopic findings that suggest malignancy. In recent years, several new imaging modalities have been developed and explored for real-time diagnosis of these lesion types. Establishing an endoscopic diagnostic tool to differentiate between adenoma and adenocarcinoma in SNADET lesions is required to select the most appropriate treatment. This review describes the current state of knowledge about preoperative endoscopic diagnosis of SNADETs, such as duodenal adenoma and duodenal adenocarcinoma. Newer endoscopic techniques, including magnifying endoscopy, may help to guide these diagnostics, but their additional advantages remain unclear, and further studies are required to clarify these issues.