Reconsideration of the Gastroparetic Syndrome.

PURPOSE OF REVIEW

Gastroparesis is a chronic disorder characterized by a constellation of foregut symptoms, including postprandial nausea, vomiting, distension, epigastric pain, and regurgitation in the absence of gastric outlet obstruction. Despite considerable research over the past decades, there remains to be only nominal understanding of disease classification, diagnostic criteria, pathogenesis, and preferred therapy.

RECENT FINDINGS

We critically reassess current approaches for disease identification and stratification, theories of causation, and treatment for gastroparesis. Gastric scintigraphy, long considered a diagnostic standard, has been re-evaluated in light of evidence showing low sensitivity, whereas newer testing modalities are incompletely validated. Present concepts of pathogenesis do not provide a unified model linking biological impairments with clinical manifestations, whereas available pharmacological and anatomical treatments lack explicit selection criteria or evidence for sustained effectiveness. We propose a disease model that embodies the re-programming of distributed neuro-immune interactions in the gastric wall by inflammatory perturbants. These interactions, combined with effects on the foregut hormonal milieu and brain-gut axis, are postulated to generate the syndromic attributes characteristically linked with gastroparesis. Research linking models of immunopathogenesis with diagnostic and therapeutic paradigms will lead to reclassifications of gastroparesis that guide future trials and technological developments.

KEY POINTS

• The term gastroparesis embodies a heterogenous array of symptoms and clinical findings based on a complex assimilation of afferent and efferent mechanisms, gastrointestinal locations, and pathologies. • There currently exists no single test or group of tests with sufficient capacity to be termed a definitional standard for gastroparesis. • Present research regarding pathogenesis suggests the importance of immune regulation of intrinsic oscillatory activity involving myenteric nerves, interstitial cells of Cajal, and smooth muscle cells. • Prokinetic pharmaceuticals remain the mainstay of management, although novel treatments are being studied that are directed to alternative muscle/nerve receptors, electromodulation of the brain-gut axis, and anatomical (endoscopic, surgical) interventions.