Comparison on the Efficacy between Partially Covered Self-Expandable Metal Stent with Funnel-Shaped Enlarged Head versus Uncovered Self-Expandable Metal Stent for Palliation of Gastric Outlet Obstruction

Abstract

Background Shape modification has been one of the methods adopted to improve stent patency but has not always translated into positive outcome. The aim of this study was to compare the efficacy of shape-modified partially covered self-expandable metal stent (SEMS) that has enlarged head versus uncovered SEMS for palliation of gastric outlet obstruction (GOO). Methods A total of 48 patients underwent insertion of either enlarged-head SEMS (n = 24) or uncovered SEMS (uSEMS) (n = 24) for palliation of GOO from July 2009 to July 2016. Patients with inoperable or advanced malignancy were included. Technical feasibility and clinical outcomes were compared. Results Technical success rate was 100% (24/24) and 95.8% (23/24) for enlarged-head SEMS group and uSEMS group, respectively. Clinical success rate was 87.5% (21/24) and 87.0% (20/23) for enlarged-head SEMS group and uSEMS group, respectively. The gastric outlet obstruction scoring system score significantly improved in both groups (p < 0.001 for both). Mean survival was similar between the groups: enlarged-head SEMS group, 99.3 days (range, 19–358 days) versus uSEMS group, 82.1 days (range, 11–231 days) (p = 0.418). The mean stent patency also showed no difference between the groups: enlarged-head SEMS group, 87.1 days (range, 8–358 days) versus uSEMS group, 60.4 days (range, 2–231 days) (p = 0.204). With enlarged-head SEMS, distal migration did not occur, but proximal migration was observed in four cases. Conclusions Distal migration was prevented by shaping the SEMS to have an enlarged head, but improvement in stent patency could not be observed.

Self-expandable metal stent of esophagogastric junction versus pyloric area obstruction in advanced gastric cancer patients

“…The other studies have noted that the analyzed factors affecting these applications include the type of stent, as well as the presence of chemotherapy and radiation therapy. [ 21 – 23 ] However, our study used a similar type of uncovered stent and patients received a similar rate of chemotherapy, indicating that our population was more homogeneous compared to other studies.…”

Covered Metal Stent after Dysfunction of Uncovered Stents for Palliation of Gastrointestinal Malignant Obstruction

“…To overcome this problem, cSEMS were developed aiming to prolong stent patency, since the covering membrane prevents SEMS from being embedded into the cancerous lesion or intestinal mucosa. However, the smooth surface of the covering reduces friction between the stent and the bowel wall, and cSEMS have been associated with a higher risk of migration [4, 9]. Since the migration of SEMS can occur with obstruction or intestinal perforation, this risk represents a major concern for endoscopists [10].…”

“…In addition to clip placement, other mechanisms have been tested to try to decrease cSEMS migration, including modifying stent designs, such as large cup- and large funnel-shaped stents [9, 34-36]. Although the results are promising with lower migration rates, there appears to be no difference in patency time, and all published studies are performed in small patient cohorts, and comparisons are difficult due to differences in stent characteristics.…”

“…However, the currently available data show no advantage of double-layered SEMS over cSEMS with regard to patency rate, and experience with these stents is limited. [9].…”

“…Although associated with good functional outcome and symptom relief, these treatment modalities carry significant morbidity [4-8]. In the last 2 decades, placement of a self-expandable metal stent (SEMS) has emerged as a safe alternative to bypass surgery, with rapid relief of obstructive symptoms, fewer postprocedural complications, shorter hospital stay, and lower costs, although late complications and the need of reintervention is higher [5, 9, 10].…”