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Chan, Walter

0000-0002-1709-8230

Mayo Clinic

Division of Gastroenterology, Hepatology, and Endoscopy, Brigham and Women's Hospital, Harvard Medical School.

Citations 4

Virtual Multidisciplinary Gastrointestinal Care Clinic Improves Patient Engagement, Satisfaction, and Outcomes at Reduced Costs and Healthcare Utilization: A Prospective Cohort Study
Berry, Sameer, Varma, Sanskriti , Basnayake, Chamara , Ahn, Joseph , Berinstein, J, Chan, Walter W. , Allen, John, Chey, William, Berry, Sameer , Berry, Sameer K , Ahn, Joseph C , Berinstein, Jeffrey , Chan, Walter , Cook, David J. , Allen, John I.

American Journal of Gastroenterology | March 20, 2026 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.14309/ajg.0000000000004002 Get It

INTRODUCTION: Chronic gastrointestinal (GI) conditions, including irritable bowel syndrome and other disorders of gut-brain interaction, are prevalent and costly, and fragmented care contributes to suboptimal outcomes. Virtual and multidisciplinary care models may improve outcomes. Objectives: We aimed to (i) characterize patients receiving virtual GI care, (ii) report patient engagement with and patient-reported outcomes after virtual multidisciplinary care, and (iii) report healthcare utilization and costs from a payer perspective among patients vs propensity score-matched controls identified from claims data. METHODS: We collected descriptive data on patient demographics, clinic provider visits, symptoms, and patient-reported outcomes from 3/2021 to 9/2022. To evaluate healthcare utilization and costs, we conducted difference-in-difference analyses using claims data compared with a propensity score-matched control group. RESULTS: Among 234 patients (71% women, mean age 45.4 ± 13.2 years), 51% received a new GI diagnosis, predominately disorders of gut-brain interaction (63%). Engagement criteria were met by 80% (n = 187), who completed a mean of 10 visits and median time-to-first appointment of 6 days. Dietitians (93%), psychologists (76%), and health coaches (64%) were frequently used. Engaged patients exhibited significant improvements from preclinic to postclinic in irritable bowel syndrome severity (226.7–145.6), symptom control (20.2%–86.6%), quality-of-life dysphoria (27.5–32.8), missed workdays (1.0–0.7), and satisfaction (37.4%–96.3%) (all P < 0.05). Compared with matched controls, a significantly smaller percent of patients had imaging (15% vs 44%; P < 0.0001) and GI-related emergency department visits (4% vs 10%; P = 0.0028), which contributed to reductions in GI-related costs ($443 per member per month; P = 0.047) and all-cause costs ($676 per member per month; P = 0.043), equating to annualized savings of $5,316 and $8,112, respectively. DISCUSSION: Virtual multidisciplinary GI care was associated with high engagement, improved clinical outcomes, and reduced healthcare utilization and costs.
Delayed Gastric Emptying in Prelung Transplant Patients Is Associated With Posttransplant Acute Cellular Rejection Independent of Reflux
Derousseau, Taylor, Chan, Walter W., Cangemi, David, Kaza, Vaidehi, Lo, Wai-Kit, Gavini, Sravanya, Chan, Walter W. , Lo, Wai–Kit , Chan, Walter , Derousseau, Taylor, Chan, Walter W., Cangemi, David, Kaza, Vaidehi, Lo, Wai-Kit, Gavini, Sravanya

Journal of Clinical Gastroenterology | February 8, 2021 | Volume: 56 | Issue: 2 | Pages: e121-e125

10.1097/mcg.0000000000001502 Get It

Goal: The goal of this study was to evaluate the relationship between pretransplant delayed gastric emptying (DGE) and posttransplant acute cellular rejection (ACR) in lung transplant recipients. Background: DGE is very prevalent (23% to 91%) after lung transplantation but pretransplant prevalence has not been well studied. DGE may lead to poor posttransplant outcomes by predisposing to microaspiration. Pretransplant testing for DGE may help identify patients at risk for negative posttransplant outcomes including ACR. Materials and Methods: A retrospective review of a prospectively collected database of consecutive patients undergoing prelung transplant evaluation at a tertiary referral center from 2010 to 2015 was performed. Patients with pretransplant gastric emptying scintigraphy were included in the study. ACR diagnosis was made using International Society for Heart and Lung Transplantation (ISHLT) histologic criteria. Typical gastroparesis symptoms at the time of gastric emptying scintigraphy and pretransplant 24-hour pH impedance monitoring (MII-pH) data was collected. Logistic regression was used for multivariate analysis. Subgroup analyses were performed to account for gastroesophageal reflux (GER). Results: A total of 83 subjects (18 with DGE, 51.8% male, mean age: 53.6 y) met the criteria for inclusion. Patients with DGE were more likely to have typical symptoms of gastroparesis, though 61.1% of DGE patients were asymptomatic. ACR was more prevalent in patients with DGE (33.3% vs. 12.3%, P =0.04). This correlation was independent of GER as measured by MII-pH on subgroup analysis (75% vs. 14.3%, n=0.02). Discussion: Lung transplant recipients with pretransplant DGE have a higher incidence of ACR, independent of GER. Routine pretransplant testing for DGE may help identify patients at greater risk for adverse posttransplant outcomes as the majority of patients with DGE are asymptomatic.
Extraesophageal syndrome of gastroesophageal reflux: relationships with lung disease and transplantation outcome
Chan, Walter W. , Ahuja, Nitin K. , Gavini, Sravanya, Vela, Marcelo F. , Chan, Walter , Fisichella, Piero Marco , Rangan, Vikram

Annals of the New York Academy of Sciences | August 18, 2020 | Volume: 1482 | Issue: 1 | Pages: 95-105

10.1111/nyas.14460 Get It

AbstractGastroesophageal reflux disease (GERD) is prevalent and may be associated with both esophageal and extraesophageal syndromes, which include various pulmonary conditions. GERD may lead to pulmonary complications through the “reflux” (aspiration) or “reflex” (refluxate‐triggered, vagally mediated airway spasm) mechanisms. While GERD may cause or worsen pulmonary disorders, changes in respiratory mechanics due to lung disease may also increase reflux. Typical esophageal symptoms are frequently absent and objective assessment with reflux monitoring is often needed for diagnosis. Impedance monitoring should be considered in addition to traditional pH study due to the involvement of both acidic and weakly acidic/nonacidic reflux. Antireflux therapy may improve outcomes of some pulmonary complications of GERD, although careful selection of a candidate is paramount to successful outcomes. Further research is needed to identify the optimal testing strategy and patient phenotypes that would benefit from antireflux therapy to improve pulmonary outcomes.
Mucosal impedance for esophageal disease: evaluating the evidence
Clarke, John O. , Ahuja, Nitin K. , Chan, Walter W. , Gyawali, C. Prakash , Horsley‐Silva, Jennifer L. , Kamal, A. N. , Vela, Marcelo F. , Xiao, Yinglian , Clarke, J , Gyawali, C P , Chan, Walter , Kamal, Afrin N.

Annals of the New York Academy of Sciences | June 26, 2020 | Volume: 1481 | Issue: 1 | Pages: 247-257

10.1111/nyas.14414 Get It

AbstractImpedance has traditionally been employed in esophageal disease as a means to assess bolus flow and reflux episodes. Recent and ongoing research has provided new and novel applications for this technology. Measurement of esophageal mucosal impedance, via either multichannel intraluminal impedance catheters or specially designed endoscopically deployed impedance catheters, provides a marker of mucosal integrity. Mucosal impedance has been shown to segregate gastroesophageal reflux disease (GERD) and eosinophilic esophagitis from non‐GERD controls and may play a role in predicting response to reflux intervention. More data are needed with regard to other esophageal subgroups, outcome studies, and functional disease. Our paper reviews the history of impedance in esophageal disease, the means of assessing baseline and mucosal impedance, data with regard to the newly developed mucosal impedance probes, the clinical utility of mucosal impedance in specific clinical conditions, and limitations in our existing knowledge, along with suggestions for future studies.