Molecular phylogeny of Hesperiidae (Lepidoptera) with an emphasis on Asian and African genera.

Despite considerable research efforts in recent years, the deeper phylogenetic relationships among skipper butterflies (Hesperiidae) remain unresolved. This is primarily because of limited sampling, especially within Asian and African lineages. In this study, we consolidated previous data and extensively sampled Asian and African taxa to elucidate the phylogenetic relationships within Hesperiidae. The molecular dataset comprised sequences from two mitochondrial and two nuclear gene regions from 563 species that represented 353 genera. Our analyses revealed seven subfamilies within Hesperiidae: Coeliadinae, Euschemoninae, Eudaminae, Pyrginae, Heteropterinae, Trapezitinae, and Hesperiinae. The systematics of most tribes and genera aligned with those of prior studies. However, notable differences were observed in several tribes and genera. Overall, the position of taxa assigned to incertae sedis in Hesperiinae is largely clarified in this study. Our results strongly support the monophyly of the tribe Tagiadini (Pyrginae), and the systematics of some genera are clarified with comprehensive discussion. We recognize 15 tribes within the subfamily Hesperiinae. Of these, nine tribes are discussed in detail: Aeromachini, Astictopterini, Erionotini, Unkanini (new status), Ancistroidini, Ismini (confirmed status), Plastingini (new status), Gretnini (confirmed status), and Eetionini (confirmed status). We propose four subtribes within Astictopterini: Hypoleucina subtrib.n., Aclerosina, Cupithina, and Astictopterina. Furthermore, we describe a new genus (Hyarotoidesgen.n.) and reinstate two genera (Zeareinst.stat. and Separeinst.stat.) as valid. Additionally, we propose several new combinations: Zea mythecacomb.n.,Sepa bononiacomb.n. & reinst.stat., and Sepa umbrosacomb.n. This study, with extensive sampling of Asian and African taxa, greatly enhances the understanding of the knowledge of the skipper tree of life.

Cold snare defect protrusion and incomplete polyp resection after forced cold snare polypectomy: a prospective observational study.

BACKGROUND: Cold snare defect protrusions (CSDPs) that occur after cold snare polypectomy (CSP) are considered indicators of incomplete polyp resection (IPR). We have sometimes experienced difficulty resecting polyps with snaring alone; in such cases, a forcible pull on the snare by the endoscopist is necessary. We call this procedure "forced CSP (FCSP)." However, no previous studies have evaluated this procedure. METHODS: This was a prospective observational study. From November 2020 to June 2021, the frequency, safety, and validity of FCSP were evaluated at our hospital. We distinguished CSP with snaring alone performed by the assistant as conventional CSP, and CSP requiring a forcible pull on the snare by the endoscopist as FCSP. RESULTS: Of 1315 polyps removed, 105 underwent FCSP (8%). The perforation rate was 0% in both groups. The rate of CSDP after the procedure was 96.2% (101/105) with FCSP and 6.4% (77/1210) with conventional CSP (P<0.001). The rate of IPR was 12.5% (13/104) with FCSP and 6.2% (75/1208) with conventional CSP (P=0.02). Multivariable analysis identified polyps located in the cecum (risk ratio [RR], 1.13; 95%CI 1.050-1.179; P=0.003) and polyps ≥6mm in diameter (RR, 2.37; 95%CI 2.146-2.542; P<0.001) as independent risk factors for FCSP. CONCLUSIONS: FCSP was performed on 105 polyps (8%) in this study. FCSP may be associated with the occurrence of CSDP and IPR. Further studies are necessary to confirm our results.

Efficacy of endoscopic submucosal resection with a ligation device for small rectal neuroendocrine tumor: study protocol of a multicenter open-label randomized control trial (BANDIT trial).

BACKGROUND: Endoscopic resection is widely accepted as a local treatment for rectal neuroendocrine tumors sized ≤ 10 mm. However, there is no consensus on the best method for the endoscopic resection of rectal neuroendocrine tumors. As a simplified endoscopic procedure, endoscopic submucosal resection with a ligation device (ESMR-L) indicates a histologically complete resection rate comparable to that of endoscopic submucosal dissection (ESD). We hypothesized that ESMR-L than ESD would be preferred for rectal neuroendocrine tumors. Hence, this trial aimed to verify whether ESMR-L is non-inferior to ESD in terms of histologically complete resection rate. METHODS: This is a prospective, open-label, multicenter, non-inferiority, randomized controlled trial of two parallel groups, conducted at the Shizuoka Cancer Center and 31 other institutions in Japan. Patients with a lesion endoscopically diagnosed as a rectal neuroendocrine tumor ≤ 10 mm are eligible for inclusion. A total of 266 patients will be recruited and randomized to undergo either ESD or ESMR-L. The primary endpoint is the rate of en bloc resection with histologically tumor-free margins (R0 resection). Secondary endpoints include en bloc resection rate, procedure time, adverse events, hospitalization days, total devices and agents cost, adverse event rate between groups with and without resection site closure, outcomes between expert and non-expert endoscopists, and factors associated with R0 resection failure. The sample size is determined based on the assumption that the R0 resection rate will be 95.2% in the ESD group and 95.3% in the ESMR-L group, with a non-inferiority margin of 8%. With a one-sided significance level of 0.05 and a power of 80%, 226 participants are required. Assuming a dropout rate of 15%, 266 patients will be included in this study. DISCUSSION: This is the first multicenter randomized controlled trial comparing ESD and ESMR-L for the R0 resection of rectal neuroendocrine tumors ≤ 10 mm. This will provide valuable information for standardizing endoscopic resection methods for rectal neuroendocrine tumors. TRIAL REGISTRATION: Japan Registry of Clinical Trials, jRCTs042210124. Registered on Jan 6, 2022.

Feasibility and Safety of Endoscopic Control for Patients with Serrated Polyposis Syndrome.

INTRODUCTION: Despite advances in endoscopic treatment, patients with serrated polyposis syndrome (SPS) occasionally require surgery due to numerous or unresectable polyps, recurrence, and treatment-related adverse events. METHODS: We retrospectively evaluated 43 patients with SPS undergoing diagnosis and treatment at Omori Red Cross Hospital from 2011 to 2022. Resection of all polyps ≥3 mm in size was planned during the clearing phase; endoscopic control was defined as complete, endoscopic polyp removal. During the surveillance phase, patients underwent annual colonoscopy and resection of newly detected polyps ≥3 mm in size. RESULTS: Thirty-eight patients (88%) achieved endoscopic control, two (5%) required surgery after endoscopic treatment because of colorectal cancer (CRC), and three (7%) have not yet achieved endoscopic control and are planning treatment. Endoscopic control was achieved with a median of four colonoscopies at 8 months. Ten polyps (median value) were resected per patient during the clearing phase. Three polyps ≥50 mm in size, six located in the appendiceal orifice, and seven with severe fibrosis could be resected by endoscopic submucosal dissection (ESD). All patients underwent treatment with a combination of cold snare polypectomy (CSP), endoscopic mucosal resection/hot polypectomy, and/or ESD. No case required surgery due to difficulty with endoscopic treatment. Delayed bleeding was observed in 2 cases (0.3%). Twenty-one patients underwent colonoscopies during the surveillance phase. Fifty-three polyps were resected using CSP; no CRC, sessile serrated lesions with dysplasia, or advanced adenoma were detected. CONCLUSION: SPS can be effectively, efficiently, and safely controlled with appropriate endoscopic management.

Effectiveness of Strategy-Focused Training in Colorectal Endoscopic Submucosal Dissection: A Retrospective Observational Study.

BACKGROUND: Colorectal ESD, an advanced minimally invasive treatment, presents technical challenges, with globally varying training methods. We analyzed the learning curve of ESD training, emphasizing preoperative strategies, notably gravity traction, to guide ESD instructors and trainee programs. METHOD: This retrospective study included 881 cases guided by an experienced supervisor. Six trainees received "strategy-focused" instruction. To evaluate the number of ESD experiences in steps, the following phases were classified based on ESD experiences of each trainees: Phase 0 (0-50 ESD), Phase 1 (51-100 ESD), Phase 2 (101-150 ESD), and Phase 3 (151-200 ESD). Lesion background, outcomes, and safety were compared across phases. Factors contributing to technical difficulty in early (Phase 0 and 1) and late phases (Phase 2 and 3) were identified, along with the utility of traction ESD with device assistance. RESULT: Treatment outcomes were favorable, with 99.8% and 94.7% en bloc resection and curative resection rates, respectively. Approximately 90% self-completion rate could be achieved after experiencing about 50 cases (92.7% in Phase 1), signifying proficiency growth despite increased case difficulty. In early phases, factors such as left-sided colon, LST-NG morphology, and severe fibrosis pose challenges. In late phases, LST-NG morphology, mild and severe fibrosis remained significant. Traction-assisted ESD, utilized in 3% of cases, comprised planned (1.1%) and rescue (1.9%) methods. Planned traction aided specific lesions, while rescue traction was common in the right colon. CONCLUSION: "Strategy-focused" ESD training consistently yields successful outcomes, effectively adapting to varying difficulty factors in different proficient stages.

The Management of Direct Oral Anticoagulants for Colorectal Endoscopic Submucosal Dissection: A Multicenter Observational Study.

BACKGROUND: There is a lack of reports on the use of direct oral anticoagulants (DOACs) during colorectal endoscopic submucosal dissection (ESD). AIMS: We aimed to assess whether the use of DOACs is associated with a higher incidence of delayed bleeding (DB) after ESD. METHODS: A total of 4175 colorectal neoplasms in 3515 patients were dissected at our hospitals during study period. We included 3909 lesions in the final analysis. The lesions were divided into two groups: the no-AT group (3668 neoplasms) and the DOAC group (241 neoplasms). We also compared the DOAC withdrawal group (154 neoplasms) and the DOAC continuation group (87 neoplasms). RESULTS: Among the 3909 lesions, DB occurred in a total of 90 cases (2.3%). The rate of DB was 2.2% (82/3668), and 3.3% (8/241), respectively. There were no significant differences in the rate of DB between the no-AT group and the DOAC group. In the DOAC group, there were no significant differences in the rate of DB between the withdrawal group (5.2%, 8/154) and the continuation group (0%, 0/87). The multivariable analysis identified the location of the lesion in the rectum (odds ratio [OR], 4.04; 95% confidence interval [CI], 2.614-6.242; p < 0.001) and lesions ≥ 30 mm in diameter (OR, 4.14; 95% CI, 2.349-7.34; p < 0.001) as independent risk factors for DB. CONCLUSIONS: Our findings suggest that DOAC use has no significant important on the rate of DB. Prospective studies are warranted to determine whether treatment with DOACs should be interrupted prior to colorectal ESD.

Molecular phylogeny, historical biogeography, and classification of Pseudocoladenia butterflies (Lepidoptera: Hesperiidae).

The range of the butterfly genus Pseudocoladenia includes several biodiversity hotspots, such as the Himalayas, mountains of southwestern China, and Sundaland. However, the taxonomic status of some of its species/subspecies remain controversial, and no previous phylogenetic or biogeographic analyses have been conducted. Herein, we determined the systematic relationships and biogeographic history of this genus by reconstructing its phylogeny based on six genes and 69 specimens as representatives of all known species/subspecies. Two species delimitation methods (Bayes Poisson Tree Processes and Bayesian Phylogenetics and Phylogeography) were also employed to assess the status of each taxon. Based on these results and morphological evidence, we identified 12 species and three subspecies in the genus and subsequently classified these into three species groups: P. fatih, P. dea, and P. dan. Five taxa, P. sadakoe (Sonan and Mitono, 1936) stat. nov., P. celebica (Fruhstorfer, 1909) stat. nov., P. fulvescens (Elwes and Edwarda, 1897) stat. nov., P. eacus (Latreille, 1823) stat. nov., and P. fabia (Evans, 1949) stat. nov. were all recognized as independent species. Additionally, two taxa, P. eacus sumatrana (Fruhstorfer, 1909) comb. nov. and P. eacus dhyana (Fruhstorfer, 1909) comb. nov., were placed under P. eacus (Latreille, 1823) stat. nov. as subspecies. Another new species distributed in N. Yunnan, Pseudocoladenia yunnana Fan, Cao & Hou sp. nov., was discovered and described. Divergence time and ancestral range estimation indicated that the most recent common ancestor of Pseudocoladenia was distributed in the Himalayas-Hengduan Mountain region and Indochina and diverged approximately 14.00 Ma. Continuous and episodic dispersal, vicariance, and extinction were used to determine the current geographic distribution of the genus. The P. fatih group had a prominently disjunct distribution between the Himalaya-Hengduan Mountain and Taiwan. Meanwhile, the P. dan group was first derived in Indochina and subsequently dispersed into the southeastern Asian archipelagoes. This study provides a reference for the evolutionary route of transoceanic distributed species in Asia and elaborates on the causes of biodiversity.

Effectiveness of switching endoscopists for repeat surveillance colonoscopy: a retrospective study.

BACKGROUND: Surveillance colonoscopy decreases colorectal cancer mortality; however, lesions are occasionally missed. Although an appropriate surveillance interval is indicated, variations may occur in the methods used, such as scope manipulation or observation. Therefore, individual endoscopists may miss certain areas. This study aimed to verify the effectiveness of performing repeat colonoscopies with a different endoscopist from the initial procedure. METHODS: We retrospectively reviewed a database of 8093 consecutive colonoscopies performed in the Omori Red Cross Hospital from January 1st 2018 to June 30th 2021. Data from repeat total colonoscopies performed within three months were collected to assess missed lesions. The patients were divided into two groups according to whether the two examinations were performed by different endoscopists (group D) or the same endoscopist (group S). The primary outcome in both groups was the missed lesion detection rate (MLDR). RESULTS: Overall, 205 eligible patients were analyzed. In total, 102 and 103 patients were enrolled in groups D and S, respectively. The MLDR was significantly higher in group D (61.8% vs. 31.1%, P < 0.0001). Multivariate logistic regression analysis for the detection of missed lesions identified performance by the different endoscopists (odds ratio, 3.38; 95% CI, 1.81-6.30), and sufficient withdrawal time (> 6 min) (odds ratio, 3.10; 95% CI, 1.12-8.61) as significant variables. CONCLUSIONS: Overall, our study showed a significant improvement in the detection of missed lesions when performed by different endoscopists. When performing repeat colonoscopy, it is desirable that a different endoscopist perform the second colonoscopy. TRIAL REGISTRATION: This study was approved by the Institutional Review Board of the Omori Red Cross Hospital on November 28, 2022 (approval number:22-43).

Endoscopic resection for gastric submucosal tumors: Japanese multicenter retrospective study.

OBJECTIVES: Limited information is available on the efficacy and safety of endoscopic resection (ER) of gastric submucosal tumors (SMTs) in Japanese endoscopic practice where ER for gastric tumors is extremely popular. METHODS: We conducted this study to elucidate the current scenario of ER for gastric SMTs in Japanese endoscopic practice. Patients (from 12 institutions) with gastric SMTs who underwent ER were enrolled from the first case until August 2020. RESULTS: We enrolled 117 patients with 118 lesions. The number of patients who underwent ER increased over the years. The mean endoscopic tumor size was 20 ± 7.2 (8-40) mm. The growth type was primarily intraluminal (90%). The mean resection and wound closure times were 58 ± 38 (range, 12-254) min and 31 ± 41 (range, 3-330) min, respectively. Complete ER was achieved for 117 (99%) lesions. Full-thickness resection rate was 44%; however, only 12 (10%) patients required abdominal paracentesis for decompression. Endoscopic treatments were completed in 115 (97%) lesions, while three lesions required conversions to laparoscopic surgery due to luminal collapse, uncontrolled bleeding, and difficulty in defect closure. Gastrointestinal stromal tumors were the most common pathology (74%). No recurrence was observed during the mean follow-up period of 4.3 ± 2.9 years. The 5-year overall survival rate was 98.9% (95% confidence interval 97.8-100%). CONCLUSION: Performance of ER for gastric SMTs is increasing in Japan. The technique seems feasible in Japanese endoscopic practice, warranting further validation in a prospective study.

Out of Asia: Intercontinental dispersals after the Eocene-Oligocene transition shaped the zoogeography of Limenitidinae butterflies (Lepidoptera: Nymphalidae).

Most members of the nymphalid subfamily Limenitidinae are distributed in tropical regions of Africa, Asia, and the Americas. Previous studies have inferred their higher-level phylogeny and found that Southeast Asia seems to be the center of origin, with numerous dispersal events to other continents. However, the complete biogeographic history of Limenitidinae butterflies is still largely unknown. We sampled 181 taxa from 164 species and used a metagenomic method to obtain 40 genes (mitogenomes and three nuclear ribosomal loci) for inferring the historical biogeography of the group. We find that Limenitidinae originated in eastern Asia during the early Eocene (ca. 52 Ma) and started to diversify and disperse into Africa before the end of Eocene. Intercontinental exchanges between Africa and eastern Asia continued in the early Miocene: Asian Adoliadini and Asian endemic taxa Bhagadatta had African origins in the Oligocene, whereas African Neptini dispersed in the opposite direction from Asia in the early Miocene. In addition, ancestors of the tribes Limenitidini and Adoliadini dispersed into the Neotropics and Australasia multiple times during the early-to-middle Miocene. Eastern Asia is the center of origin of the tribe Limenitidini, with several taxa disjunctly distributed in eastern Asia and the Americas. Our work provides a robust phylogenetic hypothesis of relationships in the tribe Limenitidini and suggests that the alala-species group of Adelpha should be placed in the genus Limenitis. Renamed taxa comb. nov. based on our findings are listed in the text.

Evaluation of cold snare polypectomy for small pedunculated (Ip) polyps with thin stalks: a prospective clinical feasibility study.

BACKGROUND: Although the use of cold snare polypectomy (CSP) has spread rapidly, no prospective studies evaluating the safety of CSP for pedunculated (Ip) polyps have been carried out. AIM: We performed this study to provide an accurate evaluation of the safety of CSP for Ip polyps. METHODS: This is a prospective study (UMIN000035687). From January 2019 to February 2021, the safety of CSP for use on Ip polyps <10 mm with thin stalks was evaluated at our hospital. The primary outcome measure was the incidence of bleeding (delayed post-polypectomy bleeding (DPPB) and immediate bleeding). RESULTS: During the study period, 89 consecutive patients (including 92 colonoscopies and 114 polyps) were prospectively enrolled. The en-bloc resection rate was 100%. The rate of DPPB after CSP was 0%, however, DPPB after conversion to HSP occurred in 1 case (33.3% (1/3)). The rate of immediate bleeding during CSP was 28.9% (33/114). Polyps with diameters ≥6 mm (OR (95% CI): 2.77 (1.041-7.376); p = .041) were extracted as independent risk factors for immediate bleeding during CSP for Ip polyps. In all, 104 (91.2%) polyps were low-grade adenomas, and the percentage of cases with negative pathological margins was 96.5% (110/114). CONCLUSIONS: CSP for Ip polyps was safe and had good outcomes. We believe that Ip polyps could be included as an indication for CSP, and that CSP may become the next step in the 'cold revolution.' To confirm our results and verify CSP's inclusion in future guidelines, prospective, randomized studies are necessary.

The feasibility and safety of endoscopic submucosal dissection of gastric lesions larger than 5 cm.

BACKGROUND: As the indications for endoscopic submucosal dissection (ESD) for early gastric cancer have been revised, diagnostic ESD has increased. However, despite the technical difficulty of ESD for large lesions, the degree to which curative resection can be achieved has not been clarified. This study investigated the feasibility and safety of ESD for gastric lesions larger than 5 cm. METHODS: This retrospective multicenter study included 3474 gastric lesions treated by ESD from April 2012 to December 2021. We compared clinicopathological characteristics and treatment outcomes between lesions ≥ 5 cm and lesions < 5 cm. RESULTS: There were 128 lesions in the ≥ 5 cm group and 3282 lesions in the < 5 cm group. In the ≥ 5 cm group, upper location and fibrosis during ESD were more common, with a lower rate of 0-IIc type. Both en bloc resection rate and R0 resection rate were comparable, but there was a difference in curative resection rate (65.6% in the ≥ 5 cm group and 91.5% in the < 5 cm group). The frequency of adverse events (post-ESD bleeding, perforation, or stenosis) was almost similar, but delayed perforation was significantly more common (1.6% in the ≥ 5 cm group vs. 0.1% in the < 5 cm group). CONCLUSIONS: About two-thirds of curative resections were obtained with ESD for early gastric lesions larger than 5 cm, but delayed complications should be noted (Number: UMIN000047725).

Effects of colorectal endoscopic submucosal dissection on postoperative abdominal symptoms: a prospective observational study.

BACKGROUND: Endoscopic submucosal dissection (ESD) is an effective procedure to resect large superficial gastrointestinal neoplasms. In gastric ESD, several studies showed the relationship between postoperative abdominal symptoms and endoscopic treatment. However, the influence of colorectal ESD on abdominal symptoms after treatment is still unknown. To the best of our knowledge, this is the first prospective multicenter study performed to investigate the impact of colorectal ESD on postoperative abdominal symptoms. This study aimed to clarify the association between change of abdominal symptoms and ESD. METHODS: This study was a prospective multicenter observational trial that enrolled 141 out of 171 patients who underwent colorectal ESD and answered the Gastrointestinal Symptom Rating Scale (GSRS) questionnaire from March 2015 to August 2019. We evaluated abdominal symptoms in the patients using the GSRS questionnaire before ESD and a few weeks after ESD. RESULTS: Comparing the GSRS before and after ESD, overall scores changed from 1.58 ± 0.58 to 1.48 ± 0.48, and the five subscales (reflux syndrome, abdominal pain, indigestion syndrome, diarrhea syndrome, and constipation syndrome) were slightly improved. Overall scores, indigestion syndrome, and constipation syndrome were statistically significantly different before and after ESD (P < 0.05). CONCLUSIONS: In GSRS, a score of ≥ 3 is often treated as a clinically significant symptom. Therefore, our findings indicated that there was no clinically significant difference. For this reason, colorectal ESD does not affect postoperative abdominal symptoms and is considered a minimally invasive treatment. The analysis of the impact of colon ESD on gastrointestinal symptoms UMIN000016914.

The feasibility of endoscopic submucosal dissection for colorectal lesions larger than 10 cm.

BACKGROUND: Although endoscopic submucosal dissection (ESD) enables en bloc removal of colorectal neoplasms, its effectiveness for larger lesions (≥ 10 cm in diameter) is undetermined. We aimed to investigate the feasibility and safety of ESD for colorectal lesions ≥ 10 cm wide. METHODS: This retrospective study included 3591 consecutive colorectal lesions managed with ESD from June 2012 through December 2020. Clinicopathological characteristics and treatment outcomes were compared between lesions ≥ 10 cm wide and lesions 5-10 cm wide. RESULTS: There were 50 patients in the ≥ 10 cm group and 270 patients in the 5-10 cm group. Among patients in the ≥ 10 cm group, lesions were most often in the rectum (50.0%), and the laterally spreading tumor-granular nodular mixed type (LST-G-M) was most prevalent (41/50, 82%). Although patients in the ≥ 10 cm group a longer mean ESD procedure time (186.0 vs. 94.4 min, p < 0.001), the dissection speed was significantly higher in this group (0.50 vs. 0.41 cm2/min, p = 0.003). The en bloc and curative resection rates were comparable between the ≥ 10 cm and 5-10 cm groups (100% vs. 99.6% and 86.0% vs. 88.5%, respectively). Although the stenosis rate was higher in the ≥ 10 cm group (4% vs. 0%), the delayed bleeding and perforation rates were similar between the two groups. CONCLUSIONS: ESD for colorectal lesions ≥ 10 cm wide is feasible and curative, even though it is associated with higher technical difficulty and longer procedure times compared with ESD for smaller lesions (Number: UMIN 000044313).

Evaluation of colorectal endoscopic submucosal dissection using a multifunctional snare: a prospective clinical feasibility study (with videos).

BACKGROUND AND AIMS: The number of colorectal endoscopic submucosal dissections (ESDs) for early colorectal cancer is expected to increase in the future; therefore, cost reduction is a clinically important issue. The SOUTEN snare (Kaneka Medics, Tokyo, Japan) is a novel multifunctional snare developed for hybrid ESD at a low price. If ESD can be performed safely using the SOUTEN snare, the same therapeutic effect can be obtained as with conventional ESD at a lower cost. The aim of this prospective, pilot, clinical feasibility study was to evaluate the safety and efficacy of ESD using the SOUTEN snare (SOUTEN-ESD). METHODS: From October 2018 to January 2019, 119 consecutive patients (121 ESD procedures, 137 colorectal neoplasms) were prospectively enrolled and treated by SOUTEN-ESD at NTT Medical Center Tokyo and Omori Red Cross Hospital. The outcomes of SOUTEN-ESD were evaluated. RESULTS: Among 137 neoplasms, SOUTEN-ESD was completed in all cases. No cases required conversion to hybrid ESD or to a dedicated ESD device. The mean procedure time was 26.1 ± 14.3 minutes. Both the en-bloc resection rate and R0 resection rate were 100%. The rate of perforation was 0%, the rate of delayed bleeding was 2.2%, and the rate of post-ESD coagulation syndrome was 2.9%. CONCLUSIONS: SOUTEN-ESD was safe and had good outcomes. Although further studies are required to examine indications for SOUTEN-ESD and confirm the results of this study, effective ESD with this novel knife is feasible. The SOUTEN snare is a realistic option for colorectal ESD. (Clinical trial registration number: UMIN 000034299.).

Endoscopic submucosal dissection of large pedunculated polyps with wide stalks: a retrospective multicenter study.

BACKGROUND: Endoscopic resection of large pedunculated colorectal polyps is technically difficult, especially when the polyp is large and has such a thick stalk that it is either too difficult or impossible to resect prophylactically by a conventional snare. Here, we evaluated the feasibility of ESD for large pedunculated polyps with wide stalks. METHODS: 29 patients with large pedunculated polyps that were not resectable by polypectomy or endoscopic mucosal resection were enrolled in the study. RESULTS: En bloc resection was achieved in 28/29 polyps. One suspended case was due to severe fibrosis with muscle retraction signs. The mean diameter of the 29 polyp heads was 39.7 (standard deviation 6.9) mm. Submucosal fibrosis was present in 16 polyps (9 mild; 7 severe). The stalks of severely fibrotic polyps were significantly thicker than those of polyps with no or mild fibrosis. The curative resection rate was 85.7 % without severe complications. CONCLUSIONS: ESD is feasible for the removal of large pedunculated polyps with wide stalks when conventional snare resection is difficult or impossible.

Impact of obesity in colorectal endoscopic submucosal dissection: single-center retrospective cohort study.

BACKGROUND: When performing colorectal endoscopic submucosal dissection (ESD) in obese patients, technically difficult cases are sometimes experienced because of difficulty with the insertion of the colonoscope, poor scope maneuverability, or an abundance of fat tissue in the submucosal layer. Since the association between obesity and colorectal ESD has not been investigated, we evaluated the clinical impact of obesity in patients who underwent colorectal ESD. METHODS: We retrospectively reviewed 535 patients who underwent colorectal ESD between April 2012 and February 2019. Patients were divided into three groups based on their body mass index (BMI): a control group (BMI < 25 kg/m2), an overweight group (25 kg/m2 ≤ BMI < 30 kg/m2), and an obese group (BMI ≥ 30 kg/m2), and the short-term clinical outcomes were analyzed to assess the safety and difficulty of colorectal ESD. RESULTS: No significant difference in the procedure times, en bloc resection rates, pathological diagnoses, or complications were seen among the groups. While the amount of sedative per body weight was significantly lower in the group with a higher BMI (flunitrazepam: 1.75 × 10-2 [1.27 × 10-2-2.34 × 10-2] mg/kg vs. 1.48 × 10-2 [1.08 × 10-2-2.03 × 10-2] mg/kg vs. 1.16 × 10-2 [0.98 × 10-2-1.54 × 10-2] mg/kg, P < 0.001; pethidine: 0.63 [0.55-0.72] mg/kg vs. 0.50 [0.46-0.56] mg/kg vs. 0.39 [0.32-0.45] mg/kg, P < 0.001), a reduction in percutaneous arterial oxygen saturation occurred significantly more frequently in the group with a higher BMI (123 [30.2%] vs. 43 [43.9%] vs. 10 [55.6%], P = 0.005). When the procedures were performed by trainees, the number of cases that required a procedure time of longer than 90 min was significantly larger in the group with a higher BMI (27 [10.8%] vs. 14 [21.9%] vs. 3 [25.0%], P = 0.033). CONCLUSIONS: This study showed that colorectal ESD could be performed safely and effectively in obese patients. However, ESD in obese patients requires attention, particularly to changes in respiratory conditions.

Recurrence of gastric cancer caused by implantation of tumor cells after curative endoscopic submucosal dissection.

A 93-year-old female underwent curative endoscopic submucosal dissection (ESD) for intramucosal gastric cancer (70 mm in diameter) in the antrum. The lesion showed an irregularly villous structure covered with mucus. En bloc resection was performed. The large resected specimen induced a longitudinal laceration on the right wall of the esophagogastric junction (EGJ) during retrieval. Unavoidably, we segmented the specimen in the stomach to facilitate retrieval. Histopathological evaluation of the specimen revealed well-to-moderately differentiated tubular and papillary adenocarcinoma. A new elevated lesion (15 mm in diameter) was found at the gastric side of the EGJ laceration scar 6 months after the first ESD, necessitating a second resection with ESD. Endoscopic, histopathological, and immunohistochemical features of the new lesion resembled those of the antral lesion. We assessed the new lesion as a recurrence of cancer caused by implantation of tumor cells in the mucosal laceration after ESD.We experienced recurrence caused by implantation of tumor cells in a mucosal laceration after curative gastric ESD. Endoscopist should be aware of the risk of implantation after gastric ESD.

Efficacy of sedation with dexmedetomidine plus propofol during esophageal endoscopic submucosal dissection.

BACKGROUND AND AIM: During endoscopic submucosal dissection for superficial esophageal cancer, patient body movement can sometimes occur, which may cause discontinuation of the procedure. Propofol and dexmedetomidine have recently been found to be useful sedatives for endoscopic submucosal dissection. This study investigated whether sedation using propofol plus dexmedetomidine can suppress the patient's body movements during esophageal endoscopic submucosal dissection and compared this combination with sedation using propofol alone. METHODS: This was a prospective double-blind randomized controlled trial. Patients with superficial esophageal cancers who underwent esophageal endoscopic submucosal dissection at Yokohama City University Hospital were prospectively enrolled and were randomly assigned to the propofol and the propofol plus dexmedetomidine groups. The primary endpoint was the incidence of restlessness. The secondary endpoints were the satisfaction score, maintenance dose of propofol, and number of rescue propofol injections. RESULTS: Sixty-six patients (propofol group: n = 33; combination group: n = 33) were included. The combination group had a significantly lower incidence of restlessness than the propofol group (3.0% vs 27.3%, P = 0.02). In the combination group, the satisfaction scores of the endoscopists were significantly higher, the maintenance dose of propofol was significantly lower, and the number of rescue propofol injections was lower than those in the propofol group (3.0% vs 18.2%, P < 0.001). Although the incidence of bradycardia was significantly higher in the combination group (30.3% vs 3.0%, P < 0.01), no serious adverse effects occurred. CONCLUSION: The propofol plus dexmedetomidine combination provided excellent sedation that effectively suppressed the patient's body movements during esophageal endoscopic submucosal dissection.

A new classification for the diagnosis of superficial non-ampullary duodenal epithelial tumors using endocytoscopy: A prospective study.

BACKGROUND AND AIM: Although the frequency of endoscopic diagnosis of superficial non-ampullary duodenal epithelial tumors (SNADETs) has been increasing in recent years, no criteria for the endoscopic diagnosis of these tumors have been established yet. The aim of this study was to assess the usefulness of endocytoscopy for diagnosis SNADETs and to establish new criteria. METHODS: This prospective study was conducted at the NTT Medical Center Tokyo from May 2019 to July 2020, and a total of 100 consecutive SNADETs were enrolled. All the endocytoscopic images of the lesions and surrounding normal mucosa were classified into three groups according to the degree of structural atypia and the nuclear morphology and size. The endocytoscopic diagnoses using endocytoscopic classification was compared with the final histopathological diagnoses. RESULTS: Data of 93 patients with 98 lesions were included in the analysis. The preoperative diagnosis by endocytoscopy coincided with the final histopathological diagnosis in 85 (86.7%) of 98 SNADETs. In addition, the sensitivity and specificity for VCL 4/5 were 87.7% and 85.4%, respectively. In contrast, the accuracy, sensitivity, and specificity of preoperative diagnosis by biopsy were 64.3%, 50.9%, and 82.9%, respectively. Preoperative diagnosis by endocytoscopy showed significantly superior accuracy and sensitivity as compared with preoperative biopsy diagnosis (P < 0.001, respectively). CONCLUSIONS: This new classification (endocytoscopic classification) allows prediction of the tumor histopathology in real time, during endocytoscopy without biopsy, and is expected to be of help in determining the appropriate therapeutic strategies for individual cases of SNADETs. (Clinical trial registration number: UMIN000038643.).