OGBN P06 Co-location of pulmonary abnormalities on high resolution CT imaging and pulmonary microaspiration reflux scan: Suggests a causative relationship

Abstract

Abstract Background The relationship between micro-aspiration of refluxate as a form of gastro-oesophageal reflux disease (GORD) and pulmonary diseases including bronchiectasis and lung fibrosis has been circumstantially suggested but not proven. Clarification of the role of GORD and microaspiration in pulmonary disease may enable targeted therapies. This study aims to determine whether there is a relationship between anatomical location of aspiration of radiological tracer on scintigraphic imaging and changes associated with pulmonary disease on high resolution computed tomographic imaging of the lung (HRCT-L). Methods Data were obtained from a prospectively populated database of patients with treatment resistant typical and atypical GORD and suspected reflux pulmonary microaspiration. Patients who underwent microaspiration studies and had concurrent HRCT-L for chest symptoms were included. Modified novel digital technique of reflux pulmonary microaspiration scintigraphy using a previously validated technique was performed to evaluate the possibility of significant GORD or extra-oesophageal symptoms, including typical symptoms such as heartburn and reflux and atypical symptoms such as throat symptoms, cough, globus, mucous, throat clearing, dysphonia and recurrent respiratory infections. HRCT-L was obtained in clinically indicated patients and compared with scintigraphic findings. Results Pulmonary reflux microaspiration scanning was performed in 121 patients (75% female, 25% male). The mean age was 67 years (range: 31 – 91 years). All patients demonstrated reflux microaspiration on scintigraphy in the supine delayed phase and all had intermittent or continuous full column gastro-oesophageal reflux. Lung parenchymal changes were apparent in 66 of 73 patients who underwent HRCT-L. Fibrotic changes were demonstrated in 51% of patients and bronchiectactic changes in 46%. Correlation at anatomical lobar levels with areas of aspiration of isotope on scintigraphic imaging was seen in 97% of fibrosis patients and 85% of bronchiectasis patients. Conclusions Modified reflux pulmonary microaspiration scintigraphy demonstrated the presence of pulmonary aspiration on delayed imaging. This is the first imaging technique with the ability to confirm the presence of lung aspiration of gastric content. Given the large proportion of cases showing lobar co-location of pulmonary abnormality on HRCT-L, this study indicates a strong relationship between aspiration of refluxate and parenchymal lung changes associated with pulmonary diseases such as IPF and bronchiectasis. There may be a significant role for modified technique scintigraphy to accurately diagnose the presence of reflux aspiration, allowing further research into pathogenesis and management of pulmonary disease.