title: [Factors related to therapeutic failure in the extraction of bile duct  stones for endoscopic retrograde colangiopancreatography ERCP].
abstract: OBJECTIVE
  Determine the factors that contribute to the technical difficulty of endoscopic clearance of common bile duct (CBD) stones in patients that underwent endoscopic retrograde cholangiopancreatography (ERCP).
  
  
  METHODS
  Prospective study included 90 patients, who underwent ERCP and an endoscopic sphincterotomy for the extraction of CBD stone. Between April 2009 and March 2010 at Arzobispo Loayza National Hospital. The technical difficult of CBD stone removal was graded in: easy (1 to 8 attempts) and difficult ( more than 8 attempts or failed).
  
  
  RESULTS
  In the bivariate analysis, we found that factors which are related to the degree of difficulty were: stone greater than or equal to 15 mm, OR = 19.8, CI (5.7 - 68.6); common bile duct greater than or equal to 15 mm, OR= 12.8, CI (3.7 - 44.3) and the use of mechanical lithotripsy, OR= 18.6, CI (1.9 -179). No association was found between the difficulty of the clearance of stone with: age, previous cholecystectomy, number of stones, stone impaction, periampullary diverticulum, sharper distal common bile duct angulation and shorter arm of common bile duct angulation.
  
  
  CONCLUSIONS
  Complete clearance of common bile duct stone was technically more difficult in patients with: stone greater than or equal to 15 mm, diameter of common bile duct greater than or equal to 15 mm and with the use of mechanical lithotripsy.
authors.affiliation: Hospital Santa Rosa Pueblo Libre – Ex Residente Hospital Loayza, Lima - Perú. dr.ramirezgarcia@gmail.com
authors.forename: Juan
authors.initials: J
authors.lastname: Ramírez García
mesh_terms: D000367:Age Factors; D000368:Aged; D002760:Cholangiopancreatography, Endoscopic Retrograde; D042882:Gallstones / Q000473:pathology / Q000601:surgery*; D006801:Humans; D008875:Middle Aged; D011446:Prospective Studies; D016717:Sphincterotomy, Endoscopic; D017211:Treatment Failure