Clarke, John

ABSTRACT Introduction Chronic gastroduodenal disorders remain challenging to manage, and new diagnostic approaches are needed to better delineate underlying causes and guide therapeutic decisions. Body Surface Gastric Mapping (BSGM) technologies combine high‐resolution gastric myoelectrical activity measurements with symptom and psychological profiling to provide mechanistic insights into gastric motor and sensory dysfunction. An International Working Group convened to derive the first consensus classification of BSGM phenotypes (the “Auckland Classification”). Methods A Technical Group conducted a systematic literature and clinical database review to identify objective test biomarkers and candidate disease mechanisms. Evidence was synthesized across 50 studies (primarily in gastroparesis, chronic nausea and vomiting, and functional dyspepsia), and BSGM phenotypes were mapped to existing treatment guidelines. Subsequently, iterative review and development of consensus was performed by a Consensus Group composed of international clinical experts familiar with BSGM. Eleven statements underlying the classification were then derived and circulated as a final survey to establish agreement. Results Six BSGM phenotypes were endorsed: three defined by myoelectrical abnormalities (Dysrhythmic, High Frequency, and Low Meal Response) and three by characteristic symptom associations (Sensorimotor, Continuous, and Delayed Onset Symptoms). Published studies plausibly linked these phenotypes to mechanisms including interstitial cell of Cajal depletion, vagal impairment, hypomotility, visceral hypersensitivity, gut‐brain dysregulation, and small bowel dysfunction. Phenotypes were also mapped to existing mechanism‐based treatment guidelines. Ten out of the eleven statements had > 80% agreement. Conclusions The Auckland Classification, derived by international consensus, presents a structured framework for BSGM‐defined patient phenotypes. Evidence and mechanism‐based treatment options are suggested for each phenotype to provide a foundation for research, further validation, and a pathway for integrating BSGM into clinical care.

Background Gastro-oesophageal reflux disease (GORD) occurs in most (∼75%) patients with systemic sclerosis (SSc) and significantly impacts quality of life. Current recommendations lack depth and therefore our aim was to produce practical, consensus-based recommendations for refractory SSc-related GORD. Methods An international, multidisciplinary steering board (SB) was assembled (n=19) consisting of clinicians (rheumatologists, gastroenterologists, gastrointestinal surgeons), an expert methodologist and patient representation. After reviewing the latest definitions of GORD and refractory GORD in the published literature, the SB collectively devised a practical definition of SSc refractory-GORD. Initial recommendations were drafted/agreed on by the SB based on review of the existing guidelines, published literature and expert opinion. Two online voting rounds were conducted to determine whether items should be accepted, with >75% and >60% SB agreement required for first and second rounds, respectively. Results There was a good response/completion rate for the initial (74%) and final (84%) voting rounds. The SB agreed on all 36 draft recommendations. The majority (n=34) were approved in the first round. Recommendations were organised according to the following categories: general approach to management (n=5), assessment (n=6), non-pharmacological (n=2) and pharmacological (n=10) management, endoscopic and surgical treatment (n=3), and special circumstances including refractory GORD and SSc-interstitial lung disease (n=3), myositis and SSc connective tissue disease-overlap (n=3) and perilung transplant (n=4). Conclusion The group of experts has drafted extended and practical recommendations for the management of SSc refractory-GORD. The necessity of a structured approach and a patient assessment is highlighted in order to provide a multidisciplinary approach to the tailored choice of the treatment. Our work also has also identified significant unmet needs and has provided a research agenda to advance the field.

INTRODUCTION: Chronic gastroduodenal disorders are highly prevalent and encompass heterogeneous pathophysiology. Autonomic dysfunction may contribute, but its relative contribution to disease pathophysiology and symptoms is unclear. This study aimed to clarify the contributions of autonomic dysfunction in gastroduodenal disorders and symptom associations using multimodal testing, hypothesizing that distinct disorder subgroups would be revealed. METHODS: This prospective observational cohort study included 80 patients with chronic gastroduodenal symptoms. Participants underwent expert clinician-led autonomic evaluation, body surface gastric mapping (BSGM; Gastric Alimetry, New Zealand), and gastric emptying scintigraphy testing. BSGM phenotyping, gastric emptying cutoffs, and autonomic criteria followed standard criteria. RESULTS: Gastroparesis was diagnosed in 27 (33.8%) patients. Autonomic dysfunction was present in 21 (26.3%) patients, and abnormal BSGM in 20 (25%). Autonomic dysfunction and abnormal BSGM were both more prevalent in gastroparesis (51.9% vs 13.2%, P = 0.001; and 44.4% vs 15.1%, P = 0.005, respectively). However, these diagnoses tended not to overlap, with patients having autonomic dysfunction generally exhibiting normal BSGM tests. Autonomic dysfunction independently predicted delayed gastric emptying (OR 13.8, P < 0.001) and was associated with earlier meal responses (higher meal response ratio, P = 0.04) and worse postprandial distress symptoms ( P < 0.05). DISCUSSION: Autonomic dysfunction independently predicted delayed gastric emptying and revealed a gastroparesis mechanism distinct from gastric myoelectrical impairment. Autonomic dysfunction altered the postprandial gastric motor response and was associated with a greater symptom burden. Multimodal physiological testing including autonomic profiling reveals distinct mechanistic subgroups in patients with chronic gastroduodenal symptoms.