Parasites and Biliary stones

Endoscopic retrograde cholangiopancreatography ١١٣
Initial cannulation often is optimal from the long or semi-long
endoscope position. Although techniques are similar to those used for
major papilla biliary and pancreatic cannulation, small-caliber guidewires
and cannulas often are required. Common methods include primary
cannulation with a 0.02-inch hydrophilic guidewire and use of a needle-
tip catheter. Secretin can be used to facilitate pancreatic secretion and to
enhance identification of the minor papilla and its orifice; in previously
failed minor papilla cannulation, administration of synthetic porcine
secretin improved cannulation from 7.7% in the placebo group to 81.3%
in the secretin group (Devereaux et al., 2003). Methylene blue and
indigo carmine have been sprayed onto the minor papilla after secretin
administration to help identify the orifice (Park et al., 2003). Needle-
knife papillotomy has been used to access minor papilla (Song et al.,
2004). EUS has been used to inject methylene blue into the dorsal
pancreatic duct to aid in localization of an otherwise invisible minor
papilla (Dewitt et al., 2004).
Pharmacologic aids to cannulation:
A number of drugs have been used to facilitate biliary and pancreatic
duct cannulation. Glugacon and hysocyamine often are used to relax
motility and have been found to be of similar efficacy (Lahoti et al.,
1997). Use of a cholecystokinin analogue helped in obtaining a
cholangiogram after an initially failed ERCP, with visualization of the
bile duct and deep cannulation in 50% of patients (Weston et al., 1997).
Wehrmann et al. (2001) found that the uses of cholecystokinin and
nitroglycerine spray are of no significant advantage.
Injection of the contrast medium and filming:
Standard contrast media (e.g. meglumine diatrizoate) at a 50% to
60% concentration (full-strength) is used for pancreatography, while 25%