Since 1990, the Wallstent has been the standard self-expanding biliary metallic stents. In 1998 the Spiral Z-stent was released.
In this study, researchers performed a randomized trial to compare the Z-stent with the Wallstent in the treatment of malignant biliary obstruction.
The research team’s findings are published in the June issue of Gastrointestinal Endoscopy.
They randomized 145 patients with unresectable malignant biliary obstruction, distal to the bile duct bifurcation, to either a 10mm diameter Wallstent or a 10mm diameter Z-stent.
|Median patency rates:|
- Z-stent = 152 days
- Wallstent = 154 days
The team included 64 patients who received a Z-stent and 68 who had a Wallstent in their analysis.
The researchers found that the tumors responsible for the obstruction were pancreatic cancer (108), cholangiocarcinoma (15), metastatic cancer (6), and papillary cancer (3).
The metallic stents were successfully placed in all patients.
They identified 7 technical problems during placement of the Z-stent and 5 with the Wallstent.
Overall, there were 21 occlusions, which required reintervention. Of these, 8 occurred with the Z-stent, and 13 with the Wallstent. The median time to reintervention was 162 days for the Z-stent and 150 days for the Wallstent.
During the course of the study 104 patients died of progressive disease or other cause. A further 7 patients remain alive with patent stents.
The research team calculated that overall median patency rates were 152 days for the Z-stent, and 154 days for the Wallstent.
Dr Raj Shah’s team concluded, “The Spiral Z-stent is comparable with the Wallstent in terms of placement, occlusion rates, and overall patency”.
“Occasional early occlusion of both stents suggests tumor characteristics instead of the size of the mesh openings in the stents as important factors”.