title: Functional anatomy of the papilla Vateri: biomechanical aspects and impact of difficult endoscopic intubation.
abstract: BACKGROUND
  Problems with intubation of the ampulla Vateri during diagnostic and therapeutic endoscopic maneuvers are a well-known feature. The ampulla Vateri was analyzed three-dimensionally to determine whether these difficulties have a structural background.
  
  
  METHODS
  Thirty-five human greater duodenal papillae were examined by light and scanning electron microscopy as well as immunohistochemically.
  
  
  RESULTS
  Histologically, highly vascularized finger-like mucosal folds project far into the lumen of the ampulla Vateri. The excretory ducts of seromucous glands containing many lysozyme-secreting Paneth cells open close to the base of the mucosal folds. Scanning electron microscopy revealed large mucosal folds inside the ampulla that continued into the pancreatic and bile duct, comparable to valves arranged in a row.
  
  
  CONCLUSIONS
  Mucosal folds form pocket-like valves in the lumen of the ampulla Vateri. They allow a unidirectional flow of secretions into the duodenum and prevent reflux from the duodenum into the ampulla Vateri. Subepithelial mucous gland secretions functionally clean the valvular crypts and protect the epithelium. The arrangement of pocket-like mucosal folds may explain endoscopic difficulties experienced when attempting to penetrate the papilla of Vater during endoscopic retrograde cholangiopancreaticographic procedures.
authors.affiliation: Department of Anatomy, Christian Albrecht University, Olshausenstrasse 40, D - 24098 Kiel, Germany. fpaulsen@anat.uni-kiel.de
authors.forename: F P
authors.initials: FP
authors.lastname: Paulsen
authors.forename: T
authors.initials: T
authors.lastname: Bobka
authors.forename: M
authors.initials: M
authors.lastname: Tsokos
authors.forename: U R
authors.initials: UR
authors.lastname: Fölsch
authors.forename: B N
authors.initials: BN
authors.lastname: Tillmann
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D002102:Cadaver; D002760:Cholangiopancreatography, Endoscopic Retrograde / Q000379:methods*; D005109:Extracellular Matrix / Q000648:ultrastructure; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007441:Intubation, Gastrointestinal / Q000379:methods; D008297:Male; D008855:Microscopy, Electron, Scanning / Q000379:methods; D008875:Middle Aged; D010183:Pancreatic Ducts / Q000033:anatomy & histology* / Q000166:cytology / Q000648:ultrastructure