NEW MEASURING ENDOSCOPIC RETROGRADE CHOLANGIOPANCREATOGRAPHY CATHETER FOR STENTING

Background: The first stent inserted by endoscopic retrograde cholangiopancreatography (ERCP) for a biliary stricture is often either too long or too short, because the length as measured on the ERCP film is a magnified image. To overcome this magnification factor, a new measuring catheter was designed to incorporate radio-opaque markers at known intervals. This is termed a radio-opaque ruler for measuring the stricture on the ERCP film. Method: The catheter is inserted until the tip sits at the position where the upper end of a stent should reach. The distance from the tip to the papilla is measured and divided by the distance between the two most distant markers. This ratio is then multiplied by the actual distance between the markers to give the exact length. One cm is added to allow for the lower end to protrude into the duodenum. When the two markers exactly mark the desired distance, the known distance between the markers becomes the exact length because the ratio is one. Results: Six patients with biliary strictures were stented using this measuring catheter. The correct stent was inserted at the first attempt every time. In two patients, the stent was trimmed down to the desired length exactly. The average time taken to complete the procedure was 35 min and no additional sedation was required after the first dose.