Browsing by Author "Rex, Douglas K."
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Item A new through-the-scope clip with anchor prongs is safe and successful for a variety of endoscopic uses(Thieme, 2024-06-21) Guardiola, John J.; Rex, Douglas K.; Thompson, Christopher C.; Mosko, Jeffrey; Ryou, Marvin; Peetermans, Joyce; Rousseau, Matthew J.; von Renteln, Daniel; Medicine, School of MedicineBackground and study aims Endoscopic through-the-scope clips (TTSC) are used for hemostasis and closure. We documented the performance of a new TTSC with anchor prongs. Patients and methods We conducted a prospective case series of the new TTSC in 50 patients with an indication for endoscopic clipping at three hospitals in the United States and Canada. Patients were followed for 30 days after the index procedure. Outcomes included defect closure and rate of serious adverse events (SAEs) related to the device or procedure. Results Fifty patients had 56 clipping procedures. Thirty-four procedures were clipping after endoscopic mucosal resection (EMR) in the colon (33) or stomach (1), 16 after polypectomy, two for hemostasis of active bleeding, and one each for fistula closure, per-oral endoscopic myotomy mucosal closure, or anchoring a feeding tube. Complete defect closure was achieved in 32 of 33 colon EMR defects and 21 of 22 other defects. All clips were placed per labeled directions for use. In 41 patients (82.0%), prophylaxis of delayed bleeding was reported as an indication for endoscopic clipping. There were three instances of delayed bleeding. There were no device-related SAEs. The only technical difficulty was one instance of premature clip deployment. Conclusions A novel TTSC with anchor prongs showed success in a range of defect closures, an acceptable safety profile, and low incidence of technical difficulties.Item Achieving cecal intubation in the difficult colon (with videos)(Elsevier, 2021) Rex, Douglas K.; Medicine, School of MedicineItem Adjusting Detection Measures for Colonoscopy: How Far Should We Go?(Elsevier, 2021-09) Rex, Douglas K.; Medicine, School of MedicineItem Advances in CRC prevention: screening and surveillance(Elsevier, 2018) Dekker, Evelien; Rex, Douglas K.; Medicine, School of MedicineColorectal cancer (CRC) is amongst the most commonly diagnosed cancers and causes of death from cancer across the world. CRC can, however, be detected in asymptomatic patients at a curable stage, and several studies have shown lower mortality among patients who undergo screening compared to those who do not. Using colonoscopy in CRC screening also results in the detection of precancerous polyps that can be directly removed during the procedure, thereby reducing the incidence of cancer. In the past decade, convincing evidence has appeared that the effectiveness of colonoscopy as CRC prevention tool is associated with the quality of the procedure. This review aims to provide an up-to-date overview of recent efforts to improve colonoscopy effectiveness of by enhancing detection and improving the completeness and safety of resection of colorectal lesions.Item Adverse events and residual lesion rate after cold endoscopic mucosal resection of serrated lesions ≥10 mm(Elsevier, 2020) McWhinney, Connor D.; Vemulapalli, Krishna C.; El-Rahyel, Ahmed; Abdullah, Noor; Rex, Douglas K.; Medicine, School of MedicineBackground and Aims Cold endoscopic mucosal resection (EMR) is being increasingly used for large serrated lesions. We sought to measure residual lesion rates and adverse events after cold EMR of large serrated lesions. Methods In a single academic center, we retrospectively examined a database of serrated class lesions ≥ 10 mm removed with cold EMR for safety and efficacy. Results Five hundred and sixty-six serrated lesions ≥10 mm in size were removed from 312 patients. We successfully contacted 223 patients (71.5%) with no reported serious adverse events that required hospitalization, repeat endoscopy, or transfusion. The residual lesion rate per lesion at first follow-up colonoscopy was 18 out of 225 (8%; 95% CI, 5-12.1). Lesions with residual were larger at polypectomy compared with lesions without recurrence (median, 23 mm vs 16 mm, p=0.017). Conclusion Cold EMR appears to be safe and effective for the removal of large serrated lesions.Item Artificial Intelligence Improves Detection at Colonoscopy: Why aren’t we all already using it?(ScienceDirect, 2022) Rex, Douglas K.; Berzin, Tyler M.; Mori, Yuichi; Medicine, School of MedicineItem Assessment of Submucosal Distortion and Mass Effect Seen at Follow-up After Colorectal Endoscopic Mucosal Resection with ORISE(Elsevier, 2022-05) Lahr, Rachel E.; DeWitt, John M.; Zhang, Dongwei; Rex, Douglas K.; Medicine, School of MedicineRecovery from spinal cord injury (SCI) and other central nervous system (CNS) trauma is hampered by limits on axonal regeneration in the CNS. Regeneration is restricted by the lack of neuron-intrinsic regenerative capacity and by the repressive microenvironment confronting damaged axons. To address this challenge, we have developed a therapeutic strategy that co-targets kinases involved in both extrinsic and intrinsic regulatory pathways. Prior work identified a kinase inhibitor (RO48) with advantageous polypharmacology (co-inhibition of targets including ROCK2 and S6K1), which promoted CNS axon growth in vitro and corticospinal tract (CST) sprouting in a mouse pyramidotomy model. We now show that RO48 promotes neurite growth from sensory neurons and a variety of CNS neurons in vitro, and promotes CST sprouting and/or regeneration in multiple mouse models of spinal cord injury. Notably, these in vivo effects of RO48 were seen in several independent experimental series performed in distinct laboratories at different times. Finally, in a cervical dorsal hemisection model, RO48 not only promoted growth of CST axons beyond the lesion, but also improved behavioral recovery in the rotarod, gridwalk, and pellet retrieval tasks. Our results provide strong evidence for RO48 as an effective compound to promote axon growth and regeneration. Further, they point to strategies for increasing robustness of interventions in pre-clinical models.Item Association of small versus diminutive adenomas and the risk for metachronous advanced adenomas: data from the New Hampshire Colonoscopy Registry(Elsevier, 2019) Anderson, Joseph C.; Rex, Douglas K.; Robinson, Christina; Butterly, Lynn F.; Medicine, School of MedicineBackground and Aims Limited data are available to investigate the impact of index adenoma size on the risk of metachronous advanced adenomas. Our goal was to examine the impact of having small (5-9 mm) versus diminutive (<5 mm) adenomas on the future risk of advanced adenomas within the categories for polyps <1 cm currently used in the United States: 1 to 2 and 3 or more tubular adenomas. Methods We included data from individuals participating in the statewide, population-based New Hampshire Colonoscopy Registry (NHCR). Groups were based on index findings: (1) 1 to 2 adenomas <5 mm (both diminutive), (2) 1 to 2 adenomas <1 cm (one or both small), (3) 3 to 10 adenomas <5 mm (all diminutive), (4) 3 to 10 adenomas <1 cm (one or more small), and (5) advanced adenomas (AA). AAs were defined as adenomas ≥1cm or those with villous elements or high-grade dysplasia or colorectal cancer (CRC). Outcomes were the absolute and adjusted risk of metachronous AAs. Covariates included age, sex, body mass index, family history of CRC, lifestyle factors, presence of serrated polyps, and time since the index examination. Results After adjusting for the covariates, we observed that having 1 to 2 adenomas with at least one 5 to 9 mm adenoma (adjusted odds ratio [AOR], 1.54; 95% confidence interval [CI], 1.12-2.11), 3 to 10 diminutive adenomas (AOR, 1.75; 95% CI, 1.03-2.95), 3 to 10 adenomas <1 cm (1 or more small) (AOR, 2.14; 95% CI, 1.39-3.29) or AAs (AOR, 2.77; 95% CI, 2.05-3.74) were associated with an increased risk for metachronous AA compared with having 1 to 2 diminutive adenomas. A further stratification of group 2 showed that those with exactly 2 small adenomas had an absolute risk of future AA of 7.6% (11/144) (95% CI, 4.3%-13.2%), higher than the absolute risk in the 1 to 2 diminutive polyp group, and similar to the risk for 3 to 10 adenomas of 8.2% (95% CI, 5.4-11.9). Conclusions For individuals with 1 to 2 adenomas <1 cm, having at least 1 small adenoma increased the metachronous risk of AA compared with having only diminutive adenomas. Furthermore, the subset with 2 small adenomas had a risk of future AA similar to the risk for 3 to 10 adenomas. These data suggest that individuals with at least 1 small adenoma may be at higher risk for future AAs and thus require closer follow-up than those with only diminutive adenomas. These data may be valuable to guideline committees for the creation of future surveillance recommendations.Item Audit of hemostatic clip use after colorectal polyp resection in an academic endoscopy unit(Thieme, 2024-04-23) Stark, Easton M.; Lahr, Rachel E.; Shultz, Jeremiah; Vemulapalli, Krishna C.; Guardiola, John J.; Rex, Douglas K.; Medicine, School of MedicineBackground and study aims Prophylactic closure of endoscopic resection defects reduces delayed hemorrhage after resection of non-pedunculated colorectal lesions ≥ 20 mm that are located proximal to the splenic flexure and removed by electrocautery. The risk of delayed hemorrhage after cold (without electrocautery) resection is much lower, and prophylactic clip closure after cold resection is generally unnecessary. The aim of this study was to audit clip use after colorectal polyp resection in routine outpatient colonoscopies at two outpatient centers within an academic medical center. Patients referred for resection of known lesions were excluded. Patients and methods Retrospective chart analysis was performed as part of a quality review of physician adherence to screening and post-polypectomy surveillance intervals. Results Among 3784 total lesions resected cold by 29 physicians, clips were placed after cold resection on 41.7% of 12 lesions ≥ 20 mm, 19.3% of 207 lesions 10 to 19 mm in size, and 2.8% of 3565 lesions 1 to 9 mm in size. Three physicians placed clips after cold resection of lesions 1 to 9 mm in 18.8%, 25.5%, and 45.0% of cases. These physicians accounted for 8.1% of 1- to 9-mm resections, but 69.7% of clips placed in this size range. Electrocautery was used for 3.1% of all resections. Clip placement overall after cold resection (3.9%) was much lower than after resection with electrocautery (71.1%), but 62.4% of all clips placed were after cold resection. Conclusions Audits of clip use in an endoscopy practice can reveal surprising findings, including high and variable rates of unnecessary use after cold resection. Audit can potentially reduce unnecessary costs, carbon emissions, and plastic waste.Item Can we do resect and discard with artificial intelligence-assisted colon polyp “optical biopsy?”(Elsevier, 2019) Rex, Douglas K.; Medicine, School of MedicineResect and discard refers to a paradigm for the management of colorectal adenomas 1-5 mm in size. In this paradigm, histology of colorectal polyps is predicted endoscopically based on surface features. Lesions that are ≤5 mm in size and predicted to be adenomas are resected endoscopically and discarded rather than submitted to pathology. Adenomas in this size range have an extremely low risk of cancer, and the cost savings of the resect and discard paradigm would be substantial. Artificial intelligence programs can improve the overall prediction for histology based on endoscopic imaging, and reduce operator dependence in endoscopic predictions. Although meta-analyses have concluded that the accuracy of endoscopic prediction is sufficiently high to institute the resect and discard paradigm in clinical practice, actual implementation has faced several obstacles. These include lack of financial incentives for endoscopists, perceived increased medical-legal risk compared with the current management paradigm of submitting all polyps to pathology, and local rules for tissue handling.