Postprandial duodenojejunal motility in health and idiopathic severe gastroparesis: from conventional analysis to nonlinear dynamics analysis

Our aim was to compare the results of the analysis of postprandial duodenojejunal motor patterns provided by a conventional computer-aided analysis with those provided by the new nonlinear mathematical method borrowed from 'chaos' theory for determining how nonlinear analysis can improve fed motor pattern analysis and detect organization of postprandial contractions. Ten patients who had been explored for an idiopathic gastroparesis, and 20 healthy volunteers underwent duodenojejunal manometric recording for 3 h after a 750 kcal meal. Computer-aided analysis on each half-hem of the postprandial recording period calculated the number of waves (NW) and the area under the curve (AUC). Pressure signals were concurrently described by phase portraits obtained by plotting each pressure Value at time t with the pressure value. at time t + 1 s. The shape and amplitude of phase portraits were visually analysed and the relative area covered (RAC) by the phase portraits was calculated. With conventional analysis, NW and AUC were maximal during the first post-meal hour then decreased with time both in healthy volunteers and gastroparetic patients. With this analysis, the only difference between patients and controls was a lower NW (P < 0.02) in patients, observed only in the duodenum. Phase portraits analysis demonstrated lower RAG, a different distribution of RAC ana more regular phase portraits in patients than in controls. Phase portraits outlined the heterogeneity of the patient group contrasting with the homogeneity of the control group when no subgroup was demonstrated by conventional analysis. We therefore conclude that the study of postprandial duodenojejunal motor behaviour could be improved by nonlinear dynamic analysis.