Use Of Impedance Planimetry In Gastroparesis: Correlating Pyloric Function With Proximal, Distal, And Total Gastric Function

INTRODUCTION: Patients with the symptoms (Sx) of gastroparesis (Gp) have unclear pathophysiology. To investigate the hypotheses that Gp Sx pats. have multiple abnormalities, we utilized several technologies: solid and liquid gastric emptying scintigraphy (GET), cutaneous and mucosal electrophysiology (EG), full thickness gastric biopsies (FTGBx) &functional luminal impedance planimetry (FLIP). METHODS: 17 symptomatic Gp Sx patients, 16 (94 %) female, and 13 (76%) idiopathic were studied. (Table 1). Pats. had baseline & follow up measures of GI Sx by standardized traditional patient reported PRO scores & Medicare-derived QOL measures (IDIOMS) pre- & post- gastric bio-electric stimulation (GES). Pats underwent cutaneous, proximal & distal mucosal EGs, proximal/liquid, distal/solid & total GET and 1-week of temporary GES to provoke possible gastric dysfunction. Subsequently, most (12/17) patients underwent FTGBs analyzed for neuromuscular status of CD-117 and S-100 cells as part of GES implant. Patients underwent subsequent pyloric function measures by FLIP for diameter & distensibility index (DI). Results, median and CIs, were compared by correlations and t-test using ‘R’ statistical software. RESULTS: FLIP evaluation revealed 15/17 (88%) patients had abnormal distensibility indices (DI). The median pyloric diameter was 13.5 [12.5, 14.4] cm, & median DI index of 5.9 [5.0, 7.4]; normal >10. Pyloric DI correlated with measurements on GETs: higher DIs had greater scores on solid GET [r = 0.55 (-0.04, 0.85), P = 0.07]. Pyloric DI correlated with GI Sx scores pre- and post-temporary GES placement: lower DIs had a trend towards greater improvements in nausea [r = -0.26(-0.73, 0.37), P = 0.49). Patients with higher DIs were found to have higher numbers of S-100 cells on FTGBx [r = 0.627, P = 0.029). We did not find any significant correlations between pyloric DI and measurements on EGs (Table 2). CONCLUSION: In a sample of patients with the Gp Sx, multiple correlations exist between proximal, distal and total gastric function with measures of pyloric physiology. Proximal gastric accommodation and/or distal antral as well as pyloric dysfunctions may play independent but related roles in pathophysiologic mechanism of gastroparesis symptoms. The identification of gastric and pyloric physiologic abnormities at baseline as well as during provocative testing may help design more optimal therapeutic plans for patients with the symptoms of gastroparesis.Table 1.: Baseline Characteristics. Continuous and discrete variables are summarized by median [IQR] and percentages, respectivelyTable 2