Long-term results of palliative placement of very low-axial force self-expandable metallic stents for malignant colorectal obstruction

Objectives

Stent placement is a standard option for palliative decompression in patients with malignant colorectal obstruction. Long-term stent placement is associated with perforation, migration, and stent occlusion. Perforation is associated with life expectancy. Several studies have shown that stents with a high axial force (AF), which is defined as the force required to maintain the stent straight after it has bent, are associated with a higher perforation rate. Therefore, we evaluated the long-term outcomes of using a very low AF stent (Niti-S Enteral Colonic Uncovered stent D-type) for palliative purposes.

Methods

Eighty-one consecutive patients with malignant colorectal obstruction in 33 medical institutions were evaluated. A stent with very low AF was placed using an endoscope system. We evaluated the adverse events (including perforation, migration, and stent occlusion), 1-year survival rate, and cumulative patency rate. Univariate analysis was conducted using Fisher's exact test. The overall survival and cumulative patency rates were assessed using the Kaplan–Meier method.

Results

The 1-year cumulative survival rate was 37.8% after stent placement. The 3-month, 6-month, and 1-year cumulative patency rates after stenting were 93.6%, 84.2%, and 75.8%, respectively. The major adverse events included stent migration (6.2%), stent occlusion (9.9%), and perforation (2.5%). Chemotherapy was administered in 26 cases (32.1%) after stenting, and bevacizumab was administered in five cases. However, no cases of perforation occurred following bevacizumab administration.

Conclusions

Our results suggest that very low AF stents are safe and effective. Therefore, they may be a suitable option for applications, such as palliation. (UMIN 000011304)