Osamu Yasui

All Publications

• Cold Snare Polypectomy in Pediatric Polyposis: A Multicenter Experience. Children (Basel, Switzerland) Friesen, H. J., Attard, T. M., Liman, A. Y., Yasui, O. W., Walsh, C. M., Gugig, R., Barakat, M. T. 2025; 12 (3)

  Abstract

  Background: Cold snare polypectomy (CSP) is a well-established and recommended technique in adult gastroenterology for the safe, efficient and complete removal of nonpedunculated lesions up to 10 mm, with piecemeal excision possible for larger lesions. However, the application of CSP in pediatric patients remains underexplored. This study summarizes a multicenter experience of CSP in pediatric polyposis patients, focusing on safety, efficacy and clinical outcomes. Methods: This retrospective study was conducted at two pediatric tertiary centers, encompassing patients aged 1 to 21 years with polyposis who underwent colonoscopy with CSP and hot snare polypectomy (HSP) between January 2022 and January 2023. Patient demographics, procedure characteristics, polyp details and clinical outcomes were analyzed. Results: A total of 477 CSPs were performed in 63 colonoscopies. Satisfactory bowel preparation was noted in 79% of procedures, with a pooled mean procedure duration of 52 min and cecal intubation achieved in 98%. Polyps resected by CSP ranged from 3 to 70 mm in size and were predominantly left-sided. Tissue retrieval was complete in 94% of cases and partial in 5%. Mild intraprocedural bleeding occurred in 25% of CSP cases, requiring endoclip placement in 19%, with no post-procedural bleeding or significant complications observed. Comparatively, CSP demonstrated favorable bleeding rates relative to HSP. At two-week follow-up, four patients required emergency evaluation for unrelated complaints, but with no adverse events attributed to CSP. Conclusions: CSP is a safe and effective technique for the removal of sessile polyps in pediatric patients with polyposis. Mild intraprocedural bleeding, when observed, was effectively managed with standard hemostatic techniques. These findings support the potential of CSP as a preferred modality for sessile polyp removal in pediatric patients, though further research is warranted to define its role across broader pediatric populations and practice settings.

  View details for DOI 10.3390/children12030291

  View details for PubMedID 40150574

• Magnetic endoscopic imaging in pediatric colonoscopy: A positive impact on procedure completion rate and procedure times. Journal of pediatric gastroenterology and nutrition Liman, A., Lal, R., Yasui, O. W., Gugig, R., Barakat, M. T. 2025

  Abstract

  To assess the impact of magnetic endoscopic imaging (MEI) on pediatric colonoscopy.We analyzed demographics, procedure completion, procedure times, complications, and whether or not MEI was used for all colonoscopies between April 27, 2023, and January 18, 2024. MEI was available for every case but used at the endoscopist's discretion. Attendings were surveyed on the frequency and duration of interventions during fellow-performed colonoscopies.We analyzed 310 colonoscopies, 113 (36%) of which used MEI. The average patient age was 13.8 years (range 5 months to 23 years). For the aggregate sample and attending-performed cases, there were fewer males in the groups that used MEI (p < 0.01). There were no other statistically significant differences in demographics or procedure indication when MEI was used. Terminal ileum (TI) intubation rate was higher when MEI was used in the aggregate sample (p = 0.02) and for fellow-performed cases (p = 0.04). TI intubation times and total procedure times were quicker when MEI was used in the aggregate sample and in both strata of attending-performed cases and fellow-performed cases (p < 0.001). One complication was reported in an attending-performed case that did not use MEI. Of the 145 fellow-performed procedures, 98 (68%) had completed surveys, 36 (36%) of which used MEI. There was no statistically significant difference in the number (p = 0.89) or duration (p = 0.96) of attending interventions when MEI was used.MEI use was associated with higher TI intubation rates, faster TI intubation, and shorter total procedure times. MEI may be a valuable adjunctive tool for pediatric endoscopists.

  View details for DOI 10.1002/jpn3.70011

  View details for PubMedID 39968857

• Plasmapheresis in ANCA-Associated Vasculitis with Active Kidney Involvement in the United States (2016-2020): A Cross-Sectional Study. Kidney360 Tao, J., Yasui, O. W., Kamdar, N. S., Zheng, S., Popat, R. A., Rehkopf, D. H., Chertow, G. M. 2024

  Abstract

  Plasmapheresis is currently recommended when antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) presents with severe kidney and/or lung involvement. This cross-sectional study aimed at describing characteristics of hospitalized patients diagnosed with AAV with severe kidney involvement undergoing plasmapheresis in the US.We defined the study population as adults hospitalized for active kidney involvement with a new diagnosis of AAV (by subtype or unspecified). We established the cohort from the 2016-2020 National Inpatient Sample by ICD-10-CM codes. In this cross-sectional study, we described demographic and clinical characteristics, associated inpatient procedures, lengths of stay, hospital costs, and disposition at discharge comparing patients treated and not treated with plasmapheresis.We identified a total of 975 cases of hospitalized AAV with acute kidney involvement in the US treated by plasmapheresis over the 5-year period. Demographic characteristics of patients who received plasmapheresis were similar to those in patients who did not (n=5670). There were no regional differences in the proportion of patients who received plasmapheresis; however, plasmapheresis was deployed more frequently among patients admitted to urban teaching hospitals relative to rural and non-teaching hospitals. Cases treated with plasmapheresis were more likely to have had acute kidney injury (AKI) (96% vs. 90%, p=0.0007), AKI requiring dialysis (52% vs 16%, p<0.001), hypoxia (40% vs. 16%, p<0.0001), and respiratory failure requiring mechanical ventilation (13% vs. 3%, p=0.0003).During 2016-2020, plasmapheresis was deployed in approximately 20% of patients being admitted for AAV and acute kidney involvement in the US. As standards of care and practice evolve, the role of plasmapheresis in the management of AAV with acute kidney involvement will require further study.

  View details for DOI 10.34067/KID.0000000000000496

  View details for PubMedID 39008365