Meike M. Hirdes

Stent-in-Stent Technique for Removal of Embedded Esophageal Self-Expanding Metal Stents

OBJECTIVES:Partially covered self-expanding metal stents (SEMSs) are regularly used for malignant and occasionally for benign esophageal disorders. Safe removal of these stents can be challenging due to embedding of the uncovered stent ends. Our aim is to report the results of removal of embedded, partially covered SEMSs by induction of pressure necrosis using the stent-in-stent technique.METHODS:Consecutive patients referred to three endoscopy units in 2007–2009, treated by the stent-in-stent technique, were reviewed. The partially covered SEMSs were inserted for malignant (n=3) or benign (n=16) conditions and were left in situ for a median of 42 days (14–189). When SEMSs were found to be embedded, a fully covered self-expanding plastic stent (SEPS) or fully covered SEMS was placed inside the partially uncovered SEMS. Subsequent removal of both stents was planned after a period of 10–14 days.RESULTS:In total, 23 stent-in-stent procedures were performed in 19 patients (10 males). Placement of a fully covered stent (SEPS: n=9 and SEMS: n=14) was technically successful in all patients. In 21 of 23 (91%) procedures, both stents were successfully removed in one procedure after a median of 12 days (5–18). In two patients, a repeat stent-in-stent procedure was needed for persistent embedding of the partially uncovered SEMSs. One (5%) procedure was complicated by severe bleeding, which could be treated endoscopically. In seven (36%) patients, the initial disorder had resolved after stent removal and no further endoscopic interventions were needed. Two (10%) patients were treated with chemoradiation or surgery for esophageal cancer after stent removal. In 10 (53%) patients, a repeat endoscopic intervention was required during follow-up because of progressive dysphagia or a persisting leak or fistula.CONCLUSIONS:The stent-in-stent technique is safe and effective for the removal of partially covered SEMSs that are embedded in the esophageal wall.

A new fully covered metal stent for the treatment of benign and malignant dysphagia: a prospective follow-up study

BACKGROUND Fully covered self-expandable metal stents (FCSEMSs) are increasingly being used for malignant and benign strictures. Particularly in the latter, FCSEMSs are known for their high migration rates. A new FCSEMS with a dog-bone shape and internal covering was developed to reduce migration risk. OBJECTIVE To evaluate recurrent dysphagia and safety of the new FC stent in benign and malignant esophageal disorders. DESIGN Prospective follow-up study. SETTING Tertiary referral center. PATIENTS Between November 2009 and February 2011, 48 consecutive patients (mean age 61 years, range 28-81 years) underwent FC stent placement for malignant (n = 33) or benign (n = 15) dysphagia. INTERVENTION FC stent placement. MAIN OUTCOME MEASUREMENTS Recurrent dysphagia and complications. RESULTS Indications for FC stent placement included esophageal cancer (n = 28), extrinsic malignant compression (n = 4), recurrent malignancy after esophagectomy (n = 1), and refractory benign esophageal stricture (n = 15). In malignant strictures, recurrent dysphagia occurred in 5 patients (15%) because of stent migration (n = 3), tissue overgrowth (n = 1), and acute edema (n = 1). In benign strictures, stents were prematurely removed in 9 (60%) patients because of stent migration (n = 5), tissue overgrowth (n = 3), and pain (n = 1). Recurrent dysphagia occurred in all patients after stent removal. Major complications occurred in 10 patients (30%) with malignant strictures and in 3 patients (20%) with benign strictures and included severe pain and/or vomiting (n = 8), fistula formation (n = 2), bleeding (n = 2), and aspiration pneumonia (n = 1). LIMITATION Nonrandomized study design. CONCLUSION Although the new FC stent effectively treats malignant dysphagia, it is associated with substantial major complications. In patients with refractory benign esophageal strictures, recurrent dysphagia occurs rapidly after removal of the new FC stent.

In vitro evaluation of the radial and axial force of self-expanding esophageal stents

BACKGROUND AND STUDY AIMS Technological innovation in esophageal stent design has progressed over the past decades, but the association between the mechanical properties of stent design and clinical outcome is still poorly understood. In this study the radial force and axial force of currently available stent designs were evaluated using an in vitro testing model. METHODS A total of 10 partially and fully covered self-expanding metal stents (SEMSs), a self-expanding plastic stent (SEPS), and an uncovered biodegradable stent were evaluated. Radial force and axial force were measured using a radial force measurement machine (RX500) and a force gauge in an oven at 37°C. RESULTS A wide range of radial force measurements were observed between the different stent designs, ranging from 4 to 83 N at 15  mm expansion. All braided nitinol stents displayed comparable mechanical characteristics with a relatively low radial force (<150 N) that gradually decreased to 0 N during expansion, whereas plastic and metal stents that were constructed in a nonbraided manner displayed an initially high radial force (>300 N) followed by a steep decline to 0 N during expansion. Conversely, peak axial force was relatively high for braided nitinol SEMSs (>1.5 N), whereas nonbraided SEMSs showed a much lower peak axial force (<1.5 N). Based on radial and axial force data, five groups of stents with comparable mechanical properties could be distinguished. CONCLUSIONS All currently available stents have a characteristic radial and axial force pattern, which may aid in the understanding of the occurrence of specific symptoms and complications after stent placement. Nonetheless, the overall clinical behavior of a stent is probably more complex and cannot be explained by these factors alone.

Cost Efficacy of Metal Stents for Palliation of Extrahepatic Bile Duct Obstruction in a Randomized Controlled Trial

BACKGROUND & AIMS Endoscopic stents are placed for palliation of extrahepatic bile duct obstruction. Although self-expandable metal stents (SEMS) remain patent longer than plastic stents, they are more expensive. We aimed to evaluate which type of stent (plastic, uncovered SEMS [uSEMS], or partially covered SEMS [pcSEMS]) is the most effective and we assessed costs. METHODS We performed a multicenter randomized trial in 219 patients at 18 hospitals in The Netherlands from February 2008 through February 2013. Patients were assigned randomly for placement of a plastic stent (n = 73), uSEMS (n = 75), or pcSEMS (n = 71) during endoscopic retrograde cholangiopancreatography. Patients were followed up for up to 1 year. Researchers were not blinded to groups. The main study end points included functional stent time and costs. RESULTS The mean functional stent times were 172 days for plastic stents, 288 days for uSEMS, and 299 days for pcSEMS (P < .005 for uSEMS and pcSEMS vs plastic). The initial placement of plastic stents (€1042 or

Endoscopic Corticosteroid Injections Do Not Reduce Dysphagia After Endoscopic Dilation Therapy in Patients With Benign Esophagogastric Anastomotic Strictures

1106) cost significantly less than placement of SEMS (€1973 or

Single and sequential biodegradable stent placement for refractory benign esophageal strictures: a prospective follow-up study.

2094) (P = .001). However, the total cost per patient at the end of the follow-up period did not differ significantly between plastic stents (€7320 or

A new partially covered metal stent for palliation of malignant dysphagia: a prospective follow-up study

7770) and SEMS (€6932 or

What is the optimal duration of stent placement for refractory, benign esophageal strictures?

7356) (P = .61). Furthermore, in patients with short survival times (≤3 mo) or metastatic disease, the total cost per patient did not differ between plastic stents and SEMS. No differences in costs were found between pcSEMS and uSEMS. CONCLUSIONS Although placement of SEMS (uncovered or partially covered) for palliation of extrahepatic bile duct obstruction initially is more expensive than placement of plastic stents, SEMS have longer functional time. The total costs after 1 year do not differ significantly with stent type. Dutch Clinical Trial Registration no: NTR1361.

Combination of biodegradable stent placement and single-dose brachytherapy is associated with an unacceptably high complication rate in the treatment of dysphagia from esophageal cancer

BACKGROUND & AIMS Benign anastomotic strictures are often difficult to treat. We assessed the efficacy of adding corticosteroid injections to endoscopic dilation therapy with Savary bougienage. METHODS In a multicenter, double-blind trial, 60 patients (mean age, 63 ± 9 years; 78% male) with an untreated cervical anastomotic stricture after esophagectomy with gastric tube reconstruction and dysphagia for at least solid food were randomly assigned to groups given 4 quadrant injections of 0.5 mL triamcinolone (40 mg/mL, n = 29) or saline (controls, n = 31) into the stricture, followed by Savary dilation to 16 mm. Dysphagia, complications, and quality of life were assessed after 1 and 2 weeks and 1, 3, and 6 months. The primary end point was a dysphagia-free period of 6 months. RESULTS In the corticosteroid group, 45% of the patients remained dysphagia-free for 6 months, compared with 36% of controls (relative risk, 1.26; 95% confidence interval, 0.68-2.36; P = .46). Median time to repeat dilation was 108 days (range, 15-180 days) in the corticosteroid group vs 42 days (range, 17-180 days) for controls (P = .11). A median number of 2 dilations (range, 1-7) was performed in the corticosteroid group vs 3 dilations (range, 1-9) in controls (relative risk, 0.76; 95% confidence interval, 0.42-1.38; P = .36). Two major intervention-related complications occurred, 1 submucosal laceration in the corticosteroid group and 1 hemorrhage in the control group. Four patients in the corticosteroid group, but none of the controls, developed Candida esophagitis (P = .03). CONCLUSIONS Corticosteroid injections do not provide a statistically significant decrease in frequency of repeat dilations or prolongation of the dysphagia-free period in patients with benign anastomotic esophagogastric strictures. Dutch Trial Registration Number 2236.

A fully covered self-expandable metal stent with antimigration features for benign biliary strictures: a prospective, multicenter cohort study

BACKGROUND AND STUDY AIM Although biodegradable stents do not require removal, a single biodegradable stent may only temporarily relieve dysphagia in patients with refractory benign esophageal stricture (RBES). The aim of this study was to evaluate the safety and long term efficacy of single and sequential biodegradable stent placement in patients with RBES. PATIENTS AND METHODS All patients who underwent biodegradable stent placement for RBES between August 2008 and March 2011 were prospectively followed to evaluate recurrent dysphagia and complication rates. RESULTS In total, 59 stents were placed in 28 patients. Patients had previously been treated with multiple dilations (n = 20) or multiple dilations and non-biodegradable esophageal stenting (n = 8). A total of 13 patients underwent sequential biodegradable stent placement (median 3, range 2 - 8) during the study period. After initial stent placement, the median dysphagia-free period was 90 days (range 14 - 618 days). Clinical success (absence of dysphagia ≥ 6 months after stent placement) was achieved in seven patients (25 %) and major complications occurred in eight patients (29 %). After placement of a second biodegradable stent, the median dysphagia-free period was 55 days (range 25 - 700 days) and clinical success was achieved in 15 % of patients. After placement of a third stent, the median dysphagia-free period was 106 days (range 90 - 150 days), but none of the patients was clinically dysphagia-free. CONCLUSION Placement of a single biodegradable stent is only temporarily effective in the vast majority of patients with RBES treated in a tertiary referral center. Sequential stenting may however be an option to avoid serial dilations.