Fully Covered,Retrievable Self-Expanding Metal Stent(Niti-S) in Palliation of Malignant Esophageal Obstruction

Abstract

"Background: The covered self expanding metal stent (SEMS) has become the main treatment option of malignant esophageal obstruction. However, the fully covered SEMS has not been as popular as the partially covered one for the fear of migration in spite of much advantage. So, we performed a prospective study to evaluate clinical efficacy of the fully covered SEMS. Methods: Between October 1998 and February 2009, 100 consecutive patients with malignant esophageal obstruction who were treated with the fully covered Niti-S stent (Niti-S, Taewoong Medical, Seoul, Korea) were included. Data collected contained technical success rate of deployment and retrieval, dysphagia score changes, success rate of esophagorespiratory fistula (ERF) resolution, survival, stent patency and complications. We also conducted analyses concerning the associations between results and variables. Result: Technical success rate of stent deployment was 100%. Dysphagia score was improved significantly from a mean of 3.1±0.8 to 1.3±0.7 (p=0.000) and 13 of 14 patients(14/100,14%) with ERF were resolved successfully with the initial stent(13/14, 92.9%). Median survival and stent patency was 74(51~97) and 54(47~67) days respectively. Recurrent dysphagia occurred in 19 patients (19/100,19%) with tumor ingrowth (2/100,2%), tumor overgrowth(7/100,7%), stent migration(6/100,6%), and food impaction(4/100,4%). Among other complications, early(≤7days) complications were chest pain (12/100, 12%), regurgitation (2/100 2%), tracheal compression (1/100, 1%) and late(>7days) ones were bleeding (2/100, 2%), persistent chest pain (2/100, 2%), and GERD (7/100, 7%). Reintervention had to be done in 19 patients (19/100,19%). Among them, endoscopic stent retrieval and replacement was done in 17 patients (17%) with 100% success rate and additional stents were inserted for the remaining two patients. There was no stent related mortality or 30 day mortality. In our analyses, there was no significant variable associated with clinical outcomes and complications. Conclusions: The fully covered Niti-S metal stent has proved its effectiveness in palliation of malignant dysphagia and safety of endoscopic retrieval with a comparably low migration rate maintaining its good advantage of lower incidence of tumor ingrowth and overgrowth. Key words; malignant dysphagia, fully covered SEMS, stent migration, stent retrieval, "