Clinical outcomes in patients undergoing multiple self-expandable metallic stent placement by stent in stent technique for malignant gastric outlet obstruction.

88 Background: Self-expandable metallic stent (SEMS) placement is widely used for relieving the obstructive symptoms of malignant gastric outlet obstruction (MGOO). The aims were to evaluate the efficacy and safety of multiple gastroduodenal stent placement by stent in stent technique and identify predictive factors about stent patency. Methods: We retrospectively analyzed data from 170 patients with GOO receiving SEMS by stent in stent technique from July 2006 to July 2018. Among them, 90 patients had been treated with gastroduodenal SEMS placement for MGOO. Technical and clinical success rates were evaluated. And, clinical outcomes with predictors of stent patency were also analyzed. Results: Among the subjects, 34.4% were treated with secondary SEMS placement, and 9.7% were treated with third SEMS placement because of the previous stent dysfunction. The median stent patency time was 15.7 weeks (range 0-89) in the first SEMS, 10.4 weeks (range 0-44) in the second SEMS, and 11.3 weeks (range 1-29) in the third SEMS. The technical and clinical success rate were 100% and 97.8% in the first SEMS, 100% and 90.3% in the second SEMS, 100% and 100% in the third SEMS. In multivariable analysis, the first SEMS placement of covered type including Comvi stent was correlated with prolonged stent patency (OR 4.549, P = 0.001). And both chemotherapy after the first SEMS placement (OR 8.248, P = 0.006) and chemotherapy after the second SEMS placement (OR 7.467, P = 0.003) were correlated with prolonged stent patency. Serious complications such as gastrointestinal hemorrhage or perforation did not occur in any patient. Conclusions: Secondary and third gastroduodenal SEMS placement by stent in stent technique is a safe and effective treatment for the first stent dysfunction in MGOO. The stent placement of covered type and chemotherapy after stent placement is the predictor of stent patency. Keywords: Malignant gastric outlet obstruction, Self-expandable metallic stent, Stent in stent technique, Stent patency, Predictive factor