preampullary adjective1 •Before an ampulla, as for example (usually, more specifically) upstream of the ampulla of Vater in the lumen of the duodenum; structures and events that are preampullary thus exist in the foregut rather than in the midgut.Patients were grouped into a preampullary or postampullary group according to the obstruction in relation to the ampulla of Vater. — 2010
