Randomized trial of stent placed above and across the sphincter of Oddi inmalignant bile duct obstruction

Background: Placement of stents above an intact sphincter of Oddi might pre vent migration of bacteria and deposition of organic material into the sten t. In patients with malignant obstructive jaundice prolongation of function time of the stent would be expected if it is placed above the sphincter of Oddi. Methods: Thirty-four patients were randomized to stent placement either abo ve (n = 17) or across (n = 17) the sphincter of Oddi. Straight 10F gauge Te flon stents were used. The patients were evaluated clinically and biochemic ally at monthly intervals during follow-up. Results: The median stent function time (i.e., the time from insertion of t he stent until stent replacement, patient death, or study termination) were 110 days (25th to 75th percentiles, 61 to 320 days) for stents placed abov e the sphincter of Oddi and 126 days (25th to 75th percentiles, 89 to 175 d ays) for stents placed across the sphincter of Oddi (nonsignificant [NS]). Stent replacement rates were 58.8% (10 of 17) in patients with stents place d above the sphincter and 29.4% (5 of 17) in patients with stents placed ac ross the sphincter (NS). Significantly more patients in the former group ex perienced stent migration (9 vs. 2, p = 0.026). The median time from stent insertion until replacement of the stents placed above and across the sphin cter of Oddi were 82 days (25th to 75th percentiles, 31 to 185 days) and 89 days (25th to 75th percentiles, 13 to 150 days), respectively (NS). Conclusions: No significant difference in overall stent performance between the two groups was found, although more stents placed above the sphincter of Oddi migrated. The time until dysfunction of the stent might be increase d if migration of stents placed inside the common bile duct could be avoide d.