Self-expandable metallic stents with an anti-reflux mechanism for malignant strictures of gastroesophageal junction

A phase III, multicenter, prospective, single-blinded, noninferiority, randomized controlled trial on the performance of a novel esophageal stent with an antireflux valve (with video)

BACKGROUND AND AIMS

Self-expanding metal stents (SEMSs) when deployed across the gastroesophageal junction (GEJ) can lead to reflux with risks of aspiration. A SEMS with a tricuspid antireflux valve (SEMS-V) was designed to address this issue. The aim of this study was to evaluate the efficacy and safety of this stent.

METHODS

A phase III, multicenter, prospective, noninferiority, randomized controlled trial was conducted on patients with malignant dysphagia requiring SEMSs to be placed across the GEJ. Patients were randomized to receive SEMSs with no valve (SEMS-NV) or SEMS-V. Postdeployment dysphagia score at 2 weeks and Gastroesophageal Reflux Disease-Health Related Quality of Life (GERD-HRQL) questionnaire score at 4 weeks were measured. Patients were followed for 24 weeks.

RESULTS

Sixty patients were randomized (SEMS-NV: 30 patients, mean age 67 ± 13 years; SEMS-V: 30 patients, mean age 65 ± 12 years). Baseline dysphagia scores (SEMS-NV, 2.5 ± .8; SEMS-V, 2.5 ± .8) and GERD-HRQL scores (SEMS-NV, 11.1 ± 8.2; SEMS-V, 12.8 ± 8.3) were similar. All SEMSs were successfully deployed. A similar proportion of patients in both arms improved from advanced dysphagia to moderate to no dysphagia (SEMS-NV, 71%; SEMS-V, 74%; 95% confidence interval, 1.93 [-17.8 to 21.7]). The dysphagia scores were also similar across all follow-up time points. Mean GERD-HRQL scores improved by 7.4 ± 10.2 points in the SEMS-V arm and by 5.2 ± 8.3 in the SEMS-NV group (P = .96). The GERD-HRQL scores were similar across all follow-up time points. Aspiration pneumonia occurred in 3.3% in the SEMS-NV arm and 6.9% in the SEMS-V arm (P = .61). Migration rates were similar (SEMS-NV, 33%; SEMS-V, 48%; P = .29). Two SEMS-V spontaneously fractured. There was no perforation, food impaction, or stent-related death in either group.

CONCLUSIONS

The SEMS-V was equally effective in relieving dysphagia as compared with the SEMS-NV. Presence of the valve did not increase the risks of adverse events. GERD symptom scores were similar between the 2 stents, implying either that the valve was not effective or that all patients on proton pump inhibitors could have masked the symptoms of GERD. Studies with objective evaluations such as fluoroscopy and/or pH/impedance are recommended. (Clinical trial registration number: NCT02159898.).

Stent placement for esophageal strictures: an update

The use of stents for esophageal strictures has evolved rapidly over the past 10 years, from rigid plastic tubes to flexible self-expanding metal (SEMS), plastic (SEPS) and biodegradable stents. For the palliative treatment of malignant dysphagia both SEMS and SEPS effectively provide a rapid relief of dysphagia. SEMS are preferred over SEPS, as randomized controlled trials have shown more technical difficulties and late migration with plastic stents. Despite specific characteristics of recently developed stents, recurrent dysphagia due to food impaction, tumoral and nontumoral tissue overgrowth, or stent migration, remain a major challenge. The efficacy of stents with an antireflux valve for patients with distal esophageal cancer varies between different stent designs. Concurrent treatment with chemotherapy and/or radiotherapy seems to be safe and effective. In the future, it can be expected that removable stents will be used as a bridge to surgery to maintain luminal patency during neoadjuvant treatment. For benign strictures, new stent designs, such as fully covered SEMS and biodegradable stents, may potentially reduce complications during stent removal.

Technical feasibility and safety of a new, implantable reflux control system to prevent gastroesophageal reflux in patients with stents placed through the lower esophageal sphincter (with video)

BACKGROUND

When an esophageal stent is placed through the lower esophageal sphincter (LES), gastroesophageal reflux symptoms may persist despite high-dose proton pump inhibitor therapy. A recently developed, short segment, uncovered nitinol stent with a tricuspid-like valve can be placed inside a previously placed esophageal stent.

OBJECTIVE

To evaluate the technical feasibility and safety of a reflux control system (RCS) in distally placed esophageal stents.

DESIGN

A prospective case series.

SETTING

Two tertiary-care referral centers.

PATIENTS

This study involved 10 patients who had an "open" stent placed through the LES and 1 patient with severe bile reflux after esophagojejunostomy.

INTERVENTION

Placement of an RCS with fluoroscopic and (in selected cases) endoscopic guidance, from April to October 2010.

MAIN OUTCOME MEASUREMENTS

Technical success of RCS placement and complications.

RESULTS

Placement of an RCS was successful on the first attempt in all patients; complete expansion to the wall of the host stent was confirmed by fluoroscopy in all cases. In 3 patients, the host stent migrated in <1 month with the RCS still inside. In 8 patients, the RCS was in place for a median of 134 days (range 33-225 days). Three patients died because of malignant disease progression. Eight RCSs were removed endoscopically, together with the host stent without complications. RCS migration did not occur.

LIMITATIONS

Small number of patients, nonrandomized design, lack of pH measurements.

CONCLUSION

Placement of an RCS in a host stent is technically feasible and safe. An RCS can be considered in symptomatic patients with open esophageal stents to prevent gastroesophageal reflux.

Self-expandable metallic stent for unresectable malignant strictures in the esophagus and cardia

OBJECTIVE

Self-expandable metallic stent (EMS) placement has been the first choice for dysphagia because of the certainty over its safety, low invasiveness, and immediate efficacy. However, there still remain some problems in relation to the EMS placement site and anticancer therapies before and after EMS placement.

METHODS

Consecutive 78 patients in whom EMS was placed due to the unresectable malignant stricture in the esophagus or cardia from July 1995 to August 2003 in our department were studied.

RESULTS

Gastroesophageal reflux was found in 5 of 8 patients after placement of conventional EMS for the stricture in the gastroesophageal junction. Meanwhile, acid and bile reflux into the esophagus were not detected by pH and bilirubin monitoring, respectively, in 6 patients after placement of the EMS with an anti-reflux mechanism for the stricture in the gastroesophageal junction. The median survival period of all patients after EMS placement was 123 days. The median survival period of 7 patients with radiotherapy only after EMS placement was 138 days and that of 17 patients with radiotherapy before EMS placement was 60 days, which was shorter than that of the former (p<0.05). On the other hand, the median survival period after hospital admission due to dysphagia of these 7 patients was longer than that of 17 patients with radiotherapy only before EMS placement, although, the difference was not significant.

CONCLUSION

EMS with an antireflux mechanism is not commercially available in Japan and approval is urgently required. The indication of radiotherapy associated with EMS placement is to be studied further.