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

Background: Placement of stents above an intact sphincter of Oddi might prevent migration of bacteria and deposition of organic material into the stent. 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 above (n = 17) or across (n = 17) the sphincter of Oddi. Straight 10F gauge Teflon stents were used. The patients were evaluated clinically and biochemically at monthly intervals during follow-up. Results: The median stent function time (i.e., the time from insertion of the stent until stent replacement, patient death, or study termination) were 110 days (25th to 75th percentiles, 61 to 320 days) for stents placed above the sphincter of Oddi and 126 days (25th to 75th percentiles, 89 to 175 days) for stents placed across the sphincter of Oddi (nonsignificant [NS]). Stent replacement rates were 58.810 of 17) in patients with stents placed above the sphincter and 29.45 of 17) in patients with stents placed across the sphincter (NS). Significantly more patients in the former group experienced stent migration (9 vs. 2, p = 0.026). The median time from stent insertion until replacement of the stents placed above and across the sphincter 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 increased if migration of stents placed inside the common bile duct could be avoided.