Published online May 21, 2019. doi: 10.3748/wjg.v25.i19.2373
Peer-review started: March 14, 2019
First decision: March 27, 2019
Revised: March 28, 2019
Accepted: April 19, 2019
Article in press: April 20, 2019
Published online: May 21, 2019
Endoscopic biliary stenting has become an established palliative treatment for patients with unresectable malignant biliary obstruction (MBO). However, stent occlusion is considered to be the most frequent delayed adverse event of stent placement. Since duodenobiliary reflux is discussed to be a major risk factor of stent occlusion, in recent years, the design of plastic stents with an anti-reflux valve has been an attractive idea for prolonging stent patency, unfortunately without convincing results and therefore limiting their use in clinical practice.
To reduce duodenobiliary reflux and thereby prolonging stent patency, we developed a new antireflux plastic stent (ARPS) with a “duckbilled” valve attached to the duodenal end of the stent. We presumed that this valve could simulate the opening and closing function of the duck’s bill. This geometry allows unimpaired antegrade bile flow into the duodenum, while it closes instantly when the intestinal pressure increases, thereby preventing the reflux of duodenal contents.
In this study, we compared the patency of ARPSs with that of traditional plastic stents (TPSs) in patients with unresectable distal MBO. The results of the study will guide the treatment of unresectable distal MBO in the future.
From February 2016 to December 2017, consecutive patients with extrahepatic MBO were recruited in our randomized clinical trial. Eligible patients were assigned to receive either an ARPS or a TPS in a randomized manner. Patients were followed by clinic visits or telephone interviews every 1-2 mo until stent exchange, death, or the final study follow-up in October 2018. The duration of stent patency, the rates of technical and clinical success, adverse events, and patient survival were documented. All data were analyzed statistically to evaluate the efficacy and safety of this new ARPS.
During the study period, 89 patients were screened for eligibility. Of these, 51 patients were excluded; thus, 38 patients were randomized to receive ARPSs or TPSs (19 per group). Stent insertion was technically successful in all patients. No significant differences were noted in the rates of clinical success, the rates of early or late adverse events, or patient survival. There was a significant difference when comparing the duration of stent patency, which was significantly longer in the ARPS group than in the TPS group.
This new ARPS is safe and effective for the palliation of unresectable distal MBO, and has a significantly longer stent patency compared with TPS. This ARPS may be an alternative option for the treatment of unresectable distal MBO.
Multiple center studies with larger samples are expected in the future to confirm and strengthen our results.