BACKGROUND: The mechanisms leading to occlusion of plastic biliary stents (PBS) are not known. OBJECTIVE: To evaluate the impact of reducing duodenobiliary reflux on stent patency rate. DESIGN: A newly designed antireflux PBS (AR-PBS) was tested in vitro by using ox bile. A prospective randomized trial in human beings was conducted. SETTING: Tertiary medical center. PATIENTS: Patients with malignant bile-duct strictures were studied. INTERVENTIONS: A PBS or an AR-PBS stent was placed by using standard techniques, and the patients were followed at regular intervals. Patients presenting with stent occlusion underwentre-stent placement with either a PBS or a metal stent. MAIN OUTCOME MEASUREMENTS: In vitro: resistance to retrograde flow and comparison of the basal and peak antegrade flow pressures between the 2 stents. In vivo: stent patency rates, complications, and the efficacy of the stents in improving the liver test. RESULTS: The AR-PBS stent could withstand a retrograde pressure gradient of >320 mm Hg compared with <1 mm Hg for the PBS. Secondary to the siphon effect of the valve, the antegrade flow resistance offered by the AR-PBS was on the negative side for all flow rates compared with PBS (P < .001). The median patency of the AR-PBS in human studies was 145 days (range, 52-252 days) compared with 101 days (range, 41-210 days) for the PBS (P = .002). Both stents were equally effective in improving the liver test, and complication rates were similar in the 2 groups. LIMITATIONS: The occluded stents were not examined microscopically. CONCLUSIONS: The antireflux biliary stent remains patent for a longer time and hence duodenobiliary reflux may be contributing to stent occlusion.
RCT Entities:
BACKGROUND: The mechanisms leading to occlusion of plastic biliary stents (PBS) are not known. OBJECTIVE: To evaluate the impact of reducing duodenobiliary reflux on stent patency rate. DESIGN: A newly designed antireflux PBS (AR-PBS) was tested in vitro by using ox bile. A prospective randomized trial in human beings was conducted. SETTING: Tertiary medical center. PATIENTS: Patients with malignant bile-duct strictures were studied. INTERVENTIONS: A PBS or an AR-PBS stent was placed by using standard techniques, and the patients were followed at regular intervals. Patients presenting with stent occlusion underwent re-stent placement with either a PBS or a metal stent. MAIN OUTCOME MEASUREMENTS: In vitro: resistance to retrograde flow and comparison of the basal and peak antegrade flow pressures between the 2 stents. In vivo: stent patency rates, complications, and the efficacy of the stents in improving the liver test. RESULTS: The AR-PBS stent could withstand a retrograde pressure gradient of >320 mm Hg compared with <1 mm Hg for the PBS. Secondary to the siphon effect of the valve, the antegrade flow resistance offered by the AR-PBS was on the negative side for all flow rates compared with PBS (P < .001). The median patency of the AR-PBS in human studies was 145 days (range, 52-252 days) compared with 101 days (range, 41-210 days) for the PBS (P = .002). Both stents were equally effective in improving the liver test, and complication rates were similar in the 2 groups. LIMITATIONS: The occluded stents were not examined microscopically. CONCLUSIONS: The antireflux biliary stent remains patent for a longer time and hence duodenobiliary reflux may be contributing to stent occlusion.
Authors: Chang-Il Kwon; Mark A Gromski; Stuart Sherman; Jeffrey J Easler; Ihab I El Hajj; James Watkins; Evan L Fogel; Lee McHenry; Glen A Lehman Journal: Dig Dis Sci Date: 2016-05-06 Impact factor: 3.199