Tumor overgrowth after expandable metallic stent placement: Experience in 583 patients with malignant gastroduodenal obstruction

OBJECTIVE. The objective of our study was to assess the incidence, predictive factors, and treatment of tumor overgrowth after placement of expandable metallic dual stents in patients with malignant gastroduodenal obstruction. MATERIALS AND METHODS. Expandable metallic dual stents were inserted under fluoroscopic guidance in 583 patients with symptomatic malignant gastroduodenal obstruction. We retrospectively reviewed prospectively collected patient records to determine the incidence and treatment of tumor overgrowth after stent placement and used multivariate analysis to determine factors predicting tumor overgrowth. RESULTS. Tumor overgrowth occurred after stent placement in 22 of 583 patients (3.8%) (range, 41-634 days; mean, 179.0 days). Duodenal lesions (odds ratio [OR], 4.505; p = 0.002), longer survival time (OR, 1.003; p = 0.001), and length of obstruction (OR, 0.783; p = 0.035) were independent predictors of tumor overgrowth. Twenty of the 22 patients were successfully treated by placement of a second dual stent, whereas the other two patients refused placement of a second stent or other further treatment. Overall, 19 of 20 patients (95%) showed improvement in symptoms after second stent placement. Duodenal perforation occurred in one of the 20 patients 125 days after placement of a second stent and was treated surgically. CONCLUSION. Tumor overgrowth seems to be an uncommon complication of expandable metallic dual stent placement in patients with malignant gastroduodenal obstruction. Tumor overgrowth is associated with duodenal lesions, longer survival time, and shorter stricture length. Tumor overgrowth can be successfully managed by coaxial insertion of a second dual-expandable metallic stent into the obstructed first stent.