My scholarship is focused on esophageal diagnostic testing modalities and metrics, and how they can enhance the clinical care of patients with esophageal symptoms (dysphagia, heartburn, regurgitation, chest pain) and diseases (such as the spectrum of gastroesophageal reflux disease (GERD), achalasia and other esophageal motor disorders, and eosinophilic esophagitis (EoE)). I have engaged in extensive esophageal clinical investigations since medical school, and find this work particularly rewarding, as it corresponds directly with my clinical esophageal work that I am so enthusiastic about (in the clinic, endoscopy suite, and esophageal function laboratory). I have been productive in the field, with >25 peer-reviewed original research publications [including >10 first- or senior-author original research publications].
I am particularly interested in how metrics from ambulatory reflux monitoring studies (both traditional and novel) can best guide appropriate management in patients with suspected GERD symptoms. We found that distal esophageal acid exposure times and symptom-reflux association with impedance-detected reflux events predict symptomatic outcomes from medical and surgical antireflux therapies (AJG 2014, CGH 2015), and phenotype these patients to best guide management (NGM 2016, NGM 2016). Further, we found that mean nocturnal baseline impedance values extracted from 24-hour pH-impedance tracings predict symptomatic outcomes with antireflux therapies (APT 2016), particularly when distal esophageal acid exposure times are borderline or equivocal (CGH 2020). We have also evaluated the utility of impedance values acquired from manometry catheters in GERD (JNM 2020, DOTE 2020). We have also sought to elucidate the relationships between genetic risk factors (single nucleotide polymorphisms), esophageal symptom burden, and findings on ambulatory reflux monitoring studies (APT 2018). These works have been cited to inform guidelines and consensus statements.
I also share a deep interest in the performance and interpretation of esophageal high-resolution manometry (HRM) studies, which are performed for evaluation of esophageal symptoms or prior to planned surgical intervention. To better maximize the diagnostic yield and value of HRM studies, we have investigated protocols for HRM studies (NGM 2015), the learning curve for interpretation of HRM studies among trainees (APT 2017), the differences between HRM interpretation software systems (NGM 2016), the importance of evaluation of upper esophageal sphincter function on HRM studies (JCG 2015), differences between achalasia subtypes identified on HRM (J Gastro 2016,NGM 2017), ancillary manometry metrics for achalasia spectrum disorders (AJP-GLP 2017), the implications of updated HRM diagnostic classifications (NGM 2017), breaks in peristaltic integrity (JNM 2018), the relationships between health-related quality of life and HRM diagnoses (NGM 2017), and the associations between obesity and symptom burden in esophageal dysmotility (CGH 2020).
Further, I seek to better understand how novel metrics and maneuvers from HRM studies can help guide esophageal motor diagnosis and symptom management. In this respect, we have assessed the utility of provocative maneuvers at HRM such as multiple rapid swallows, which we have found are reproducible (NGM 2014), may guide antireflux surgical planning (NGM 2016), and represent the most common HRM abnormality among patients with systemic sclerosis (CGH 2016). We have also studied a novel HRM metric termed esophagogastric junction-contractile integral, that reflects antireflux barrier function (DOTE 2016), and changes with surgical intervention (fundoplication or myotomy; NGM 2016). I am interested in the utility of impedance values acquired from the resting landmark phase (JNM 2020) and esophageal contraction (contractile segment impedance, DOTE 2020) of HRM studies.
Beyond my peer-reviewed research publications summarized above, I have also co-authored curricula for gastroenterology trainees (NGM 2018), clinical reviews and education pieces (GIE Clinics of North America 2014, CGR 2016, New Gastroenterologist 2017, JAMA 2018, DDS 2018, JAMA 2018, CGR 2019, NGM 2019, JAMA 2020, DDS 2020), invited editorials (APT 2018, DDS 2020), book chapters (Washington Manual 2013, Diagnosis and Treatment of GERD 2016, Washington Manual 2016, Evaluation and Management of Dysphagia 2020), and society clinical practice guidelines (AJG 2020, Gastroenterology 2020).