Stabilization of ERK-Phosphorylated METTL3 by USP5 Increases m6A Methylation.

N6-methyladenosine (m6A) is the most abundant mRNA modification and is installed by the METTL3-METTL14-WTAP methyltransferase complex. Although the importance of m6A methylation in mRNA metabolism has been well documented recently, regulation of the m6A machinery remains obscure. Through a genome-wide CRISPR screen, we identify the ERK pathway and USP5 as positive regulators of the m6A deposition. We find that ERK phosphorylates METTL3 at S43/S50/S525 and WTAP at S306/S341, followed by deubiquitination by USP5, resulting in stabilization of the m6A methyltransferase complex. Lack of METTL3/WTAP phosphorylation reduces decay of m6A-labeled pluripotent factor transcripts and traps mouse embryonic stem cells in the pluripotent state. The same phosphorylation can also be found in ERK-activated human cancer cells and contribute to tumorigenesis. Our study reveals an unrecognized function of ERK in regulating m6A methylation.

YTHDF2/m6 A/NF-κB axis controls anti-tumor immunity by regulating intratumoral Tregs.

N6 -methyladenosine (m6 A) in messenger RNA (mRNA) regulates immune cells in homeostasis and in response to infection and inflammation. The function of the m6 A reader YTHDF2 in the tumor microenvironment (TME) in these contexts has not been explored. We discovered that the loss of YTHDF2 in regulatory T (Treg) cells reduces tumor growth in mice. Deletion of Ythdf2 in Tregs does not affect peripheral immune homeostasis but leads to increased apoptosis and impaired suppressive function of Treg cells in the TME. Elevated tumor necrosis factor (TNF) signaling in the TME promotes YTHDF2 expression, which in turn regulates NF-κB signaling by accelerating the degradation of m6 A-modified transcripts that encode NF-κB-negative regulators. This TME-specific regulation of Treg by YTHDF2 points to YTHDF2 as a potential target for anti-cancer immunotherapy, where intratumoral Treg cells can be targeted to enhance anti-tumor immune response while avoiding Treg cells in the periphery to minimize undesired inflammations.

Transcriptome-wide Mapping of Internal N7-Methylguanosine Methylome in Mammalian mRNA.

N7-methylguanosine (m7G) is a positively charged, essential modification at the 5' cap of eukaryotic mRNA, regulating mRNA export, translation, and splicing. m7G also occurs internally within tRNA and rRNA, but its existence and distribution within eukaryotic mRNA remain to be investigated. Here, we show the presence of internal m7G sites within mammalian mRNA. We then performed transcriptome-wide profiling of internal m7G methylome using m7G-MeRIP sequencing (MeRIP-seq). To map this modification at base resolution, we developed a chemical-assisted sequencing approach that selectively converts internal m7G sites into abasic sites, inducing misincorporation at these sites during reverse transcription. This base-resolution m7G-seq enabled transcriptome-wide mapping of m7G in human tRNA and mRNA, revealing distribution features of the internal m7G methylome in human cells. We also identified METTL1 as a methyltransferase that installs a subset of m7G within mRNA and showed that internal m7G methylation could affect mRNA translation.

Superagers Resist Typical Age-Related White Matter Structural Changes.

Superagers are elderly individuals with the memory ability of people 30 years younger and provide evidence that age-related cognitive decline is not inevitable. In a sample of 64 superagers (mean age, 81.9; 59% women) and 55 typical older adults (mean age, 82.4; 64% women) from the Vallecas Project, we studied, cross-sectionally and longitudinally over 5 years with yearly follow-ups, the global cerebral white matter status as well as region-specific white matter microstructure assessment derived from diffusivity measures. Superagers and typical older adults showed no difference in global white matter health (total white matter volume, Fazekas score, and lesions volume) cross-sectionally or longitudinally. However, analyses of diffusion parameters revealed the better white matter microstructure in superagers than in typical older adults. Cross-sectional differences showed higher fractional anisotropy (FA) in superagers mostly in frontal fibers and lower mean diffusivity (MD) in most white matter tracts, expressed as an anteroposterior gradient with greater group differences in anterior tracts. FA decrease over time is slower in superagers than in typical older adults in all white matter tracts assessed, which is mirrored by MD increases over time being slower in superagers than in typical older adults in all white matter tracts except for the corticospinal tract, the uncinate fasciculus, and the forceps minor. The better preservation of white matter microstructure in superagers relative to typical older adults supports resistance to age-related brain structural changes as a mechanism underpinning the remarkable memory capacity of superagers, while their regional aging pattern is in line with the last-in-first-out hypothesis.

Rescue Therapy for Failed Mechanical Thrombectomy in Acute Ischemic Stroke: A Pooled Analysis of the Society of Vascular and Interventional Neurology Registry.

OBJECTIVE: We aimed to evaluate the association between rescue therapy (RT) and functional outcomes compared to medical management (MM) in patients presenting after failed mechanical thrombectomy (MT). METHODS: This cross-sectional study utilized prospectively collected and maintained data from the Society of Vascular and Interventional Neurology Registry, spanning from 2011 to 2021. The cohort comprised patients with large vessel occlusions (LVOs) with failed MT. The primary outcome was the shift in the degree of disability, as gauged by the modified Rankin Scale (mRS) at 90 days. Additional outcomes included functional independence (90-day mRS score of 0-2), symptomatic intracranial hemorrhage (sICH), and 90-day mortality. RESULTS: Of a total of 7,018 patients, 958 presented failed MT and were included in the analysis. The RT group comprised 407 (42.4%) patients, and the MM group consisted of 551 (57.5%) patients. After adjusting for confounders, the RT group showed a favorable shift in the overall 90-day mRS distribution (adjusted common odds ratio = 1.79, 95% confidence interval [CI] = 1.32-2.45, p < 0.001) and higher rates of functional independence (RT: 28.8% vs MM: 15.7%, adjusted odds ratio [aOR] = 1.93, 95% CI = 1.21-3.07, p = 0.005) compared to the MM group. RT also showed lower rates of sICH (RT: 3.8% vs MM: 9.1%, aOR = 0.52, 95% CI = 0.28-0.97, p = 0.039) and 90-day mortality (RT: 33.4% vs MM: 45.5%, aOR = 0.61, 95% CI = 0.42-0.89, p = 0.009). INTERPRETATION: Our findings advocate for the utilization of RT as a potential treatment strategy for cases of LVO resistant to first-line MT techniques. Prospective studies are warranted to validate these observations and optimize the endovascular approach for failed MT patients. ANN NEUROL 2024.

Brain and cognitive changes in patients with long COVID compared with infection-recovered control subjects.

Between 2.5 and 28% of people infected with SARS-CoV-2 suffer Long COVID or persistence of symptoms for months after acute illness. Many symptoms are neurological, but the brain changes underlying the neuropsychological impairments remain unclear. This study aimed to provide a detailed description of the cognitive profile, the pattern of brain alterations in Long COVID and the potential association between them. To address these objectives, 83 patients with persistent neurological symptoms after COVID-19 were recruited, and 22 now healthy controls chosen because they had suffered COVID-19 but did not experience persistent neurological symptoms. Patients and controls were matched for age, sex and educational level. All participants were assessed by clinical interview, comprehensive standardized neuropsychological tests and structural MRI. The mean global cognitive function of patients with Long COVID assessed by ACE III screening test (Overall Cognitive level - OCLz= -0.39± 0.12) was significantly below the infection recovered-controls (OCLz= +0.32± 0.16, p< 0.01). We observed that 48% of patients with Long COVID had episodic memory deficit, with 27% also impaired overall cognitive function, especially attention, working memory, processing speed and verbal fluency. The MRI examination included grey matter morphometry and whole brain structural connectivity analysis. Compared to infection recovered controls, patients had thinner cortex in a specific cluster centred on the left posterior superior temporal gyrus. In addition, lower fractional anisotropy (FA) and higher radial diffusivity (RD) were observed in widespread areas of the patients' cerebral white matter relative to these controls. Correlations between cognitive status and brain abnormalities revealed a relationship between altered connectivity of white matter regions and impairments of episodic memory, overall cognitive function, attention and verbal fluency. This study shows that patients with neurological Long COVID suffer brain changes, especially in several white matter areas, and these are associated with impairments of specific cognitive functions.

Hydrogen-Stabilized ScYNdGd Medium-Entropy Alloy for Hydrogen Storage.

The research on the functional properties of medium- and high-entropy alloys (MEAs and HEAs) has been in the spotlight recently. Many significant discoveries have been made lately in hydrogen-based economy-related research where these alloys may be utilized in all of its key sectors: water electrolysis, hydrogen storage, and fuel cell applications. Despite the rapid development of MEAs and HEAs with the ability to reversibly absorb hydrogen, the research is limited to transition-metal-based alloys that crystallize in body-centered cubic solid solution or Laves phase structures. To date, no study has been devoted to the hydrogenation of rare-earth-element (REE)-based MEAs or HEAs, as well as to the alloys crystallizing in face-centered-cubic (FCC) or hexagonal-close-packed structures. Here, we elucidate the formation and hydrogen storage properties of REE-based ScYNdGd MEA. More specifically, we present the astounding stabilization of the single-phase FCC structure induced by the hydrogen absorption process. Moreover, the measured unprecedented high storage capacity of 2.5 H/M has been observed after hydrogenation conducted under mild conditions that proceeded without any phase transformation in the material. The studied MEA can be facilely activated, even after a long passivation time. The results of complementary measurements showed that the hydrogen desorption process proceeds in two steps. In the first, hydrogen is released from octahedral interstitial sites at relatively low temperatures. In the second, high-temperature process, it is associated with the desorption of hydrogen atoms stored in tetrahedral sites. The presented results may impact future research of a novel group of REE-based MEAs and HEAs with adaptable hydrogen storage properties and a broad scope of possible applications.

Scavenging Reactive Lipids to Prevent Oxidative Injury.

Oxidative injury due to elevated levels of reactive oxygen species is implicated in cardiovascular diseases, Alzheimer's disease, lung and liver diseases, and many cancers. Antioxidant therapies have generally been ineffective at treating these diseases, potentially due to ineffective doses but also due to interference with critical host defense and signaling processes. Therefore, alternative strategies to prevent oxidative injury are needed. Elevated levels of reactive oxygen species induce lipid peroxidation, generating reactive lipid dicarbonyls. These lipid oxidation products may be the most salient mediators of oxidative injury, as they cause cellular and organ dysfunction by adducting to proteins, lipids, and DNA. Small-molecule compounds have been developed in the past decade to selectively and effectively scavenge these reactive lipid dicarbonyls. This review outlines evidence supporting the role of lipid dicarbonyls in disease pathogenesis, as well as preclinical data supporting the efficacy of novel dicarbonyl scavengers in treating or preventing disease.

Lenalidomide promotes the development of TP53-mutated therapy-related myeloid neoplasms.

There is a growing body of evidence that therapy-related myeloid neoplasms (t-MNs) with driver gene mutations arise in the background of clonal hematopoiesis (CH) under the positive selective pressure of chemo- and radiation therapies. Uncovering the exposure relationships that provide selective advantage to specific CH mutations is critical to understanding the pathogenesis and etiology of t-MNs. In a systematic analysis of 416 patients with t-MN and detailed prior exposure history, we found that TP53 mutations were significantly associated with prior treatment with thalidomide analogs, specifically lenalidomide. We demonstrated experimentally that lenalidomide treatment provides a selective advantage to Trp53-mutant hematopoietic stem and progenitor cells (HSPCs) in vitro and in vivo, the effect of which was specific to Trp53-mutant HSPCs and was not observed in HSPCs with other CH mutations. Because of the differences in CK1α degradation, pomalidomide treatment did not provide an equivalent level of selective advantage to Trp53-mutant HSPCs, providing a biological rationale for its use in patients at high risk for t-MN. These findings highlight the role of lenalidomide treatment in promoting TP53-mutated t-MNs and offer a potential alternative strategy to mitigate the risk of t-MN development.

N6-methyladenosine promotes induction of ADAR1-mediated A-to-I RNA editing to suppress aberrant antiviral innate immune responses.

Among over 150 distinct RNA modifications, N6-methyladenosine (m6A) and adenosine-to-inosine (A-to-I) RNA editing represent 2 of the most studied modifications on mammalian mRNAs. Although both modifications occur on adenosine residues, knowledge on potential functional crosstalk between these 2 modifications is still limited. Here, we show that the m6A modification promotes expression levels of the ADAR1, which encodes an A-to-I RNA editing enzyme, in response to interferon (IFN) stimulation. We reveal that YTH N6-methyladenosine RNA binding protein 1 (YTHDF1) mediates up-regulation of ADAR1; YTHDF1 is a reader protein that can preferentially bind m6A-modified transcripts and promote translation. Knockdown of YTHDF1 reduces the overall levels of IFN-induced A-to-I RNA editing, which consequently activates dsRNA-sensing pathway and increases expression of various IFN-stimulated genes. Physiologically, YTHDF1 deficiency inhibits virus replication in cells through regulating IFN responses. The A-to-I RNA editing activity of ADAR1 plays important roles in the YTHDF1-dependent IFN responses. Therefore, we uncover that m6A and YTHDF1 affect innate immune responses through modulating the ADAR1-mediated A-to-I RNA editing.

Do patients actually understand? An evaluation of the informed consent process for endoscopic procedures in rural Uganda.

INTRODUCTION: Improving surgical access in low- and middle-income countries is vital for the 5 billion people who lack safe surgical care. Tailoring a culturally sensitive approach to consent is essential for patient comprehension and comfort, thereby alleviating the effects of resource constraints and advancing equitable care. This study examines the consenting process for endoscopy at Kyabirwa Surgical Center in Kyabirwa, Jinja, Uganda, to assess patients' knowledge and attitudes as a potential barrier to participating in endoscopic procedures. METHODS: All adult upper endoscopy (EGD) and colonoscopy patients were recruited to participate in a survey of their demographics, knowledge, and attitudes toward their procedure. All patients received a standard consultation explaining the procedure and its risks and benefits. RESULTS: 75 patients were included; median age was 54 years and 56% (n = 42) were women. 92% (n = 69) of patients had never had an endoscopy before and 73% (n = 55) of patients were scheduled for an EGD while the remaining 27% (n = 20) were scheduled for a colonoscopy. Most patients 80% (n = 60) had a basic understanding of what an endoscopy is and 87% (n = 65) its diagnostic purpose. Few patients 15% (n = 11) knew of the most common side effects or if they would have a surgical scar 27% (n = 20). Overall, 46.7% (n = 35) of patients were moderately or severely fearful of getting an endoscopy. Additionally, 45.3% (n = 34) of patients were moderately or severely fearful of receiving anesthesia during their endoscopic procedure. Despite this fear, most patients 85.3% (n = 64) stated that they understood the benefits of the procedure either very well or extremely well. CONCLUSIONS: Most patients understood the role that an endoscopic procedure plays in their care and its potential benefits. Despite this, many patients continued to have high levels of fear associated with both the endoscopic procedure and with receiving anesthesia during their procedure. Future patient education should focus on addressing patients' fears and the risks of undergoing an endoscopy, which may improve the utilization of surgical services.

Collaborative international partnership: Enabling the development of a state-of-the-art minimally invasive surgical center in rural Uganda through telementoring.

BACKGROUND: Access to minimally invasive surgery (MIS) is limited in Sub-Saharan African countries. In 2019, the Mount Sinai Department of Surgery in New York collaborated with local Ugandans to construct the Kyabirwa Surgical Center (KSC), an independent, replicable, self-sustaining ambulatory surgical center in Uganda. We developed a focused MIS training program using a combination of in-person training and supervised telementoring. We present the results of our initial MIS telementoring experience. METHODS: We worked jointly with Ugandan staff to construct the KSC in the rural province of Jinja. A solar-powered backup battery system ensured continuous power availability. Underground fiber optic cables were installed to provide stable high-speed Internet. The local Ugandan general surgeon (JOD) underwent a mini-fellowship in MIS and then trained extensively using the Fundamentals of Laparoscopic Surgery program. After a weeklong in-person session to train the Ugandan OR team, JOD performed laparoscopic cases with telementoring, which was conducted remotely by surgeons in New York via audiovisual feeds from the KSC OR. RESULTS: From October 2021 to February 2024, JOD performed 61 telementored laparoscopic operations at KSC including 37 appendectomies and 24 cholecystectomies. Feedback was provided regarding patient positioning, port placement, surgical technique, instrument use, and critical steps of the operation. There were no intra-operative complications. Postoperatively, field medical workers visited patients at home to collect follow-up information. Two superficial wound infections (3.3%) were reported in the short-term follow-up. CONCLUSION: Telementoring can be safely implemented to assist surgeons in previously underserved areas to provide advanced laparoscopic surgical care to the local patient population.

The METTL5-TRMT112 N6-methyladenosine methyltransferase complex regulates mRNA translation via 18S rRNA methylation.

Ribosomal RNAs (rRNAs) have long been known to carry chemical modifications, including 2'O-methylation, pseudouridylation, N6-methyladenosine (m6A), and N6,6-dimethyladenosine. While the functions of many of these modifications are unclear, some are highly conserved and occur in regions of the ribosome critical for mRNA decoding. Both 28S rRNA and 18S rRNA carry single m6A sites, and while the methyltransferase ZCCHC4 has been identified as the enzyme responsible for the 28S rRNA m6A modification, the methyltransferase responsible for the 18S rRNA m6A modification has remained unclear. Here, we show that the METTL5-TRMT112 methyltransferase complex installs the m6A modification at position 1832 of human 18S rRNA. Our work supports findings that TRMT112 is required for METTL5 stability and reveals that human METTL5 mutations associated with microcephaly and intellectual disability disrupt this interaction. We show that loss of METTL5 in human cancer cell lines and in mice regulates gene expression at the translational level; additionally, Mettl5 knockout mice display reduced body size and evidence of metabolic defects. While recent work has focused heavily on m6A modifications in mRNA and their roles in mRNA processing and translation, we demonstrate here that deorphanizing putative methyltransferase enzymes can reveal previously unappreciated regulatory roles for m6A in noncoding RNAs.

Elucidation of physico-chemical principles of high-density lipoprotein-small RNA binding interactions.

Extracellular small RNAs (sRNAs) are abundant in many biofluids, but little is known about their mechanisms of transport and stability in RNase-rich environments. We previously reported that high-density lipoproteins (HDLs) in mice were enriched with multiple classes of sRNAs derived from the endogenous transcriptome, but also from exogenous organisms. Here, we show that human HDL transports tRNA-derived sRNAs (tDRs) from host and nonhost species, the profiles of which were found to be altered in human atherosclerosis. We hypothesized that HDL binds to tDRs through apolipoprotein A-I (apoA-I) and that these interactions are conferred by RNA-specific features. We tested this using microscale thermophoresis and electrophoretic mobility shift assays and found that HDL binds to tDRs and other single-stranded sRNAs with strong affinity but did not bind to double-stranded RNA or DNA. Furthermore, we show that natural and synthetic RNA modifications influenced tDR binding to HDL. We demonstrate that reconstituted HDL bound to tDRs only in the presence of apoA-I, and purified apoA-I alone were able to bind sRNA. Conversely, phosphatidylcholine vesicles did not bind tDRs. In summary, we conclude that HDL binds to single-stranded sRNAs likely through nonionic interactions with apoA-I. These results highlight binding properties that likely enable extracellular RNA communication and provide a foundation for future studies to manipulate HDL-sRNA interactions for therapeutic approaches to prevent or treat disease.

Taxifolin inhibits NETosis through activation of Nrf2 and provides protective effects in models of lupus and antiphospholipid syndrome.

OBJECTIVES: Taxifolin (dihydroquercetin) is a bioactive plant flavonoid that exhibits anti-inflammatory and anti-oxidative properties. We hypothesized that taxifolin might be an effective dietary supplement to ameliorate symptoms arising from thrombo-inflammatory diseases such as lupus and antiphospholipid syndrome (APS). METHODS: We used in vitro assays and a mouse model to determine mechanisms by which taxifolin inhibits neutrophil extracellular trap (NET) formation (i.e., NETosis) and venous thrombosis in lupus and APS. RESULTS: At doses ranging from 0.1 to 1 µg/ml, taxifolin inhibited NETosis from control neutrophils stimulated with autoantibodies isolated from lupus and APS patients, and its suppressive effects were mitigated by blocking the antioxidant transcription factor Nrf2 (nuclear factor erythroid 2-related factor 2). Furthermore, taxifolin at a dose as low as 20 mg/kg/day reduced in vivo NETosis in thrombo-inflammatory mouse models of lupus and APS while also significantly attenuating autoantibody formation, inflammatory cytokine production, and large-vein thrombosis. CONCLUSION: Our study is the first to demonstrate the protective effects of taxifolin in the context of lupus and APS. Importantly, our study also suggests a therapeutic potential to neutralize neutrophil hyperactivity and NETosis that could have relevance to a variety of thrombo-inflammatory diseases.

Technical details and outcomes of peroral endoscopic myotomy with fundoplication: the first U.S. experience (with video).

BACKGROUND AND AIMS: Peroral endoscopic myotomy (POEM) is an established endoscopic treatment for achalasia; however, post-POEM rates of GERD remain a significant cause of concern. Single-session POEM with fundoplication (POEM-F) to treat achalasia was recently described to reduce post-POEM GERD. This study aims to report the technical feasibility, safety, and early outcomes of the first U.S. cohort of POEM-F. METHODS: We retrospectively reviewed all patients with achalasia treated with POEM-F at our center. The primary endpoint was technical success, defined as the successful completion of all steps of the POEM-F procedure. RESULTS: Six patients (mean age, 50 ± 4.8 years; 1 woman) underwent POEM-F for achalasia. Technical success was achieved in all patients (6/6), and no major immediate or delayed (up to 30 days postprocedure) adverse events were seen. At the 1-month follow-up visit, the mean Eckardt score decreased from 8.8 ± 1.1 to .3 ± .5. The GERD health-related quality of life and reflux symptom index scores obtained at the 1-month follow-up, with patients on proton pump inhibitors, were 2.3 ± 3.7 and 2.2 ± 2.5, respectively. CONCLUSIONS: This first case series on POEM-F in the United States suggests that POEM-F is feasible and safe with excellent short-term outcomes.

Novel through-the-scope suture closure of colonic EMR defects (with video).

BACKGROUND AND AIMS: Large colon polyps removed by EMR can be complicated by delayed bleeding. Prophylactic defect clip closure can reduce post-EMR bleeding. Larger defects can be challenging to close using through-the-scope clips (TTSCs), and proximal defects are difficult to reach using over-the-scope techniques. A novel, through-the-scope suturing (TTSS) device allows direct closure of mucosal defects without scope withdrawal. The goal of this study was to evaluate the rate of delayed bleeding after the closure of large colon polyp EMR sites with TTSS. METHODS: A multicenter retrospective cohort study was performed involving 13 centers. All defect closure by TTSS after EMR of colon polyps ≥2 cm from January 2021 to February 2022 were included. The primary outcome was rate of delayed bleeding. RESULTS: A total of 94 patients (52% female; mean age, 65 years) underwent EMR of predominantly right-sided (n = 62 [66%]) colon polyps (median size, 35 mm; interquartile range, 30-40 mm) followed by defect closure with TTSS during the study period. All defects were successfully closed with TTSS alone (n = 62 [66%]) or with TTSS and TTSCs (n = 32 [34%]), using a median of 1 (interquartile range, 1-1) TTSS system. Delayed bleeding occurred in 3 patients (3.2%), with 2 requiring repeated endoscopic evaluation/treatment (moderate). CONCLUSION: TTSS alone or with TTSCs was effective in achieving complete closure of all post-EMR defects, despite a large lesion size. After TTSS closure with or without adjunctive devices, delayed bleeding was seen in 3.2% of cases. Further prospective studies are needed to validate these findings before wider adoption of TTSS for large polypectomy closure.

Through-the-scope suture closure of peroral endoscopic myotomy mucosal incision sites.

BACKGROUND : Peroral endoscopic myotomy (POEM) is now widely used for esophageal motility disorders including achalasia. Closure of the mucosal incision site is a critical step of the procedure. We evaluated the use of a novel through-the-scope (TTS) suture system for closure of POEM mucosal incision sites. METHODS : We retrospectively reviewed consecutive patients who underwent POEM with TTS suture closure at our institution between February and July 2021. Technical success was defined as complete mucosal incision site closure using TTS suturing, without the need for adjunctive devices. Continuous variables are presented as median (interquartile range [IQR]) or mean (SD). RESULTS : 35 consecutive patients (median age 58 years [IQR 46.5-72]; 54.3 % female) underwent POEM with attempted mucosal closure by TTS suturing. Technical success was achieved in 32 patients (91.4 %) with a mean closure time of 12.4 (SD 6.9) minutes. The median mucosal incision length at time of closure was 2.5 cm (IQR 2-2.5). Overall, 17 patients (53.1 %) required ≥ 2 TTS suture systems and 3 patients (8.6 %) required additional TTS clips to achieve secure mucosal closure. No adverse events were encountered. CONCLUSIONS : TTS suturing was effective and safe for POEM mucosotomy closure. However, prospective comparative trials and cost-effectiveness analyses are warranted before routine adoption.

Zenker's peroral endoscopic myotomy for management of large Zenker's diverticulum.

BACKGROUND: Zenker's diverticulum peroral endoscopic myotomy (zPOEM) is a minimally invasive treatment strategy for Zenker's diverticulum, with excellent results for management of small-to-moderate Zenker's diverticulum. We evaluated its use in the management of large Zenker's diverticulum. METHODS: This was a retrospective multicenter cohort study across 11 international centers including adult patients with large Zenker's diverticulum ≥ 40 mm treated by zPOEM between March 2017 and March 2022. The primary outcome was clinical success (dysphagia score ≤ 1 without need for further intervention). Secondary outcomes included technical success (complete myotomy as intended), adverse events (AEs), and rate of recurrence. RESULTS: 83 patients (male 62.7 %, mean age 72.6 [SD 11.5] years) underwent zPOEM for treatment of large Zenker's diverticulum (median size 50 mm, interquartile range [IQR] 41-55 mm, range 40-80 mm). The zPOEM procedure was technically successful in 82 patients (98.8 %), with a mean procedure time of 48.7 (SD 23.2) minutes. Clinical success was achieved in 71 patients (85.5 %). Median (IQR) symptom scores improved significantly from baseline for dysphagia (2 2 3 vs. 0 [0-2]; P < 0.001), regurgitation (3 2 3 4 vs. 0 [0-0]; P < 0.001), and respiratory symptoms (2 [0-3] vs. 0 [0-0]; P < 0.001). Among patients achieving clinical success, only one recurrence (1.4 %) was recorded during a median follow-up of 12.2 months (IQR 3-28). Post-procedure AEs, all mild to moderate, occurred in four patients (4.8 %). CONCLUSION: This study demonstrated safe and effective use of zPOEM in the management of large Zenker's diverticulum.

Through-the-scope suture closure of nonampullary duodenal endoscopic mucosal resection defects: a retrospective multicenter cohort study.

BACKGROUND: Delayed bleeding is among the most common adverse events associated with endoscopic mucosal resection (EMR) of nonampullary duodenal polyps. We evaluated the rate of delayed bleeding and complete defect closure using a novel through-the-scope (TTS) suturing system for the closure of duodenal EMR defects. METHODS: We reviewed the electronic medical records of patients who underwent EMR for nonampullary duodenal polyps of ≥ 10 mm and prophylactic defect closure with TTS suturing between March 2021 and May 2022 at centers in the USA. We evaluated the rates of delayed bleeding and complete defect closure. RESULTS: 36 nonconsecutive patients (61 % women; mean [SD] age, 65 [12] years) underwent EMR of ≥ 10-mm duodenal polyps followed by attempted defect closure with TTS suturing. The mean (SD) lesion size was 29 (19) mm, defect size was 37 (25) mm; eight polyps (22 %) involved > 50 % of the lumen circumference. Complete closure was achieved in all cases (78 % with TTS suturing alone), using a median of one TTS suturing kit. There were no cases of delayed bleeding and no adverse events attributed to application of the TTS suturing device. CONCLUSION: Prophylactic closure of nonampullary duodenal EMR defects using TTS suturing resulted in a high rate of complete closure and no delayed bleeding events.