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 duodenoj ejunal motor patterns provided by a conventional computer-aided analysis wi th those provided by the new nonlinear mathematical method borrowed from 'c haos' theory for determining how nonlinear analysis can improve fed motor p attern analysis and detect organization of postprandial contractions. Ten p atients who had been explored for an idiopathic gastroparesis, and 20 healt hy volunteers underwent duodenojejunal manometric recording for 3 h after a 750 kcal meal. Computer-aided analysis on each half-hem of the postprandia l recording period calculated the number of waves (NW) and the area under t he curve (AUC). Pressure signals were concurrently described by phase portr aits obtained by plotting each pressure Value at time t with the pressure v alue. at time t + 1 s. The shape and amplitude of phase portraits were visu ally analysed and the relative area covered (RAC) by the phase portraits wa s calculated. With conventional analysis, NW and AUC were maximal during th e 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 differ ent distribution of RAC ana more regular phase portraits in patients than i n 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 stud y of postprandial duodenojejunal motor behaviour could be improved by nonli near dynamic analysis.